skia WIPjarred/canvas

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diff --git a/src/deps/skia/include/core/SkCanvas.h b/src/deps/skia/include/core/SkCanvas.h
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+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkCanvas_DEFINED
+#define SkCanvas_DEFINED
+
+#include "include/core/SkBlendMode.h"
+#include "include/core/SkClipOp.h"
+#include "include/core/SkColor.h"
+#include "include/core/SkFontTypes.h"
+#include "include/core/SkImageInfo.h"
+#include "include/core/SkM44.h"
+#include "include/core/SkMatrix.h"
+#include "include/core/SkPaint.h"
+#include "include/core/SkPoint.h"
+#include "include/core/SkRasterHandleAllocator.h"
+#include "include/core/SkRect.h"
+#include "include/core/SkRefCnt.h"
+#include "include/core/SkSamplingOptions.h"
+#include "include/core/SkScalar.h"
+#include "include/core/SkSize.h"
+#include "include/core/SkString.h"
+#include "include/core/SkSurfaceProps.h"
+#include "include/core/SkTypes.h"
+#include "include/private/SkDeque.h"
+#include "include/private/SkMacros.h"
+
+#include <cstring>
+#include <memory>
+#include <vector>
+
+#ifndef SK_SUPPORT_LEGACY_GETTOTALMATRIX
+#define SK_SUPPORT_LEGACY_GETTOTALMATRIX
+#endif
+
+class AutoLayerForImageFilter;
+class GrBackendRenderTarget;
+class GrRecordingContext;
+class GrSlug;
+class SkBaseDevice;
+class SkBitmap;
+class SkData;
+class SkDrawable;
+struct SkDrawShadowRec;
+class SkFont;
+class SkGlyphRunBuilder;
+class SkGlyphRunList;
+class SkImage;
+class SkImageFilter;
+class SkPaintFilterCanvas;
+class SkPath;
+class SkPicture;
+class SkPixmap;
+class SkRegion;
+class SkRRect;
+struct SkRSXform;
+struct SkCustomMesh;
+class SkSpecialImage;
+class SkSurface;
+class SkSurface_Base;
+class SkTextBlob;
+class SkVertices;
+
+namespace skstd {
+    template<typename T> class optional;
+}
+
+/** \class SkCanvas
+    SkCanvas provides an interface for drawing, and how the drawing is clipped and transformed.
+    SkCanvas contains a stack of SkMatrix and clip values.
+
+    SkCanvas and SkPaint together provide the state to draw into SkSurface or SkBaseDevice.
+    Each SkCanvas draw call transforms the geometry of the object by the concatenation of all
+    SkMatrix values in the stack. The transformed geometry is clipped by the intersection
+    of all of clip values in the stack. The SkCanvas draw calls use SkPaint to supply drawing
+    state such as color, SkTypeface, text size, stroke width, SkShader and so on.
+
+    To draw to a pixel-based destination, create raster surface or GPU surface.
+    Request SkCanvas from SkSurface to obtain the interface to draw.
+    SkCanvas generated by raster surface draws to memory visible to the CPU.
+    SkCanvas generated by GPU surface uses Vulkan or OpenGL to draw to the GPU.
+
+    To draw to a document, obtain SkCanvas from SVG canvas, document PDF, or SkPictureRecorder.
+    SkDocument based SkCanvas and other SkCanvas subclasses reference SkBaseDevice describing the
+    destination.
+
+    SkCanvas can be constructed to draw to SkBitmap without first creating raster surface.
+    This approach may be deprecated in the future.
+*/
+class SK_API SkCanvas {
+public:
+
+    /** Allocates raster SkCanvas that will draw directly into pixels.
+
+        SkCanvas is returned if all parameters are valid.
+        Valid parameters include:
+        info dimensions are zero or positive;
+        info contains SkColorType and SkAlphaType supported by raster surface;
+        pixels is not nullptr;
+        rowBytes is zero or large enough to contain info width pixels of SkColorType.
+
+        Pass zero for rowBytes to compute rowBytes from info width and size of pixel.
+        If rowBytes is greater than zero, it must be equal to or greater than
+        info width times bytes required for SkColorType.
+
+        Pixel buffer size should be info height times computed rowBytes.
+        Pixels are not initialized.
+        To access pixels after drawing, call flush() or peekPixels().
+
+        @param info      width, height, SkColorType, SkAlphaType, SkColorSpace, of raster surface;
+                         width, or height, or both, may be zero
+        @param pixels    pointer to destination pixels buffer
+        @param rowBytes  interval from one SkSurface row to the next, or zero
+        @param props     LCD striping orientation and setting for device independent fonts;
+                         may be nullptr
+        @return          SkCanvas if all parameters are valid; otherwise, nullptr
+    */
+    static std::unique_ptr<SkCanvas> MakeRasterDirect(const SkImageInfo& info, void* pixels,
+                                                      size_t rowBytes,
+                                                      const SkSurfaceProps* props = nullptr);
+
+    /** Allocates raster SkCanvas specified by inline image specification. Subsequent SkCanvas
+        calls draw into pixels.
+        SkColorType is set to kN32_SkColorType.
+        SkAlphaType is set to kPremul_SkAlphaType.
+        To access pixels after drawing, call flush() or peekPixels().
+
+        SkCanvas is returned if all parameters are valid.
+        Valid parameters include:
+        width and height are zero or positive;
+        pixels is not nullptr;
+        rowBytes is zero or large enough to contain width pixels of kN32_SkColorType.
+
+        Pass zero for rowBytes to compute rowBytes from width and size of pixel.
+        If rowBytes is greater than zero, it must be equal to or greater than
+        width times bytes required for SkColorType.
+
+        Pixel buffer size should be height times rowBytes.
+
+        @param width     pixel column count on raster surface created; must be zero or greater
+        @param height    pixel row count on raster surface created; must be zero or greater
+        @param pixels    pointer to destination pixels buffer; buffer size should be height
+                         times rowBytes
+        @param rowBytes  interval from one SkSurface row to the next, or zero
+        @return          SkCanvas if all parameters are valid; otherwise, nullptr
+    */
+    static std::unique_ptr<SkCanvas> MakeRasterDirectN32(int width, int height, SkPMColor* pixels,
+                                                         size_t rowBytes) {
+        return MakeRasterDirect(SkImageInfo::MakeN32Premul(width, height), pixels, rowBytes);
+    }
+
+    /** Creates an empty SkCanvas with no backing device or pixels, with
+        a width and height of zero.
+
+        @return  empty SkCanvas
+
+        example: https://fiddle.skia.org/c/@Canvas_empty_constructor
+    */
+    SkCanvas();
+
+    /** Creates SkCanvas of the specified dimensions without a SkSurface.
+        Used by subclasses with custom implementations for draw member functions.
+
+        If props equals nullptr, SkSurfaceProps are created with
+        SkSurfaceProps::InitType settings, which choose the pixel striping
+        direction and order. Since a platform may dynamically change its direction when
+        the device is rotated, and since a platform may have multiple monitors with
+        different characteristics, it is best not to rely on this legacy behavior.
+
+        @param width   zero or greater
+        @param height  zero or greater
+        @param props   LCD striping orientation and setting for device independent fonts;
+                       may be nullptr
+        @return        SkCanvas placeholder with dimensions
+
+        example: https://fiddle.skia.org/c/@Canvas_int_int_const_SkSurfaceProps_star
+    */
+    SkCanvas(int width, int height, const SkSurfaceProps* props = nullptr);
+
+    /** Private. For internal use only.
+    */
+    explicit SkCanvas(sk_sp<SkBaseDevice> device);
+
+    /** Constructs a canvas that draws into bitmap.
+        Sets kUnknown_SkPixelGeometry in constructed SkSurface.
+
+        SkBitmap is copied so that subsequently editing bitmap will not affect
+        constructed SkCanvas.
+
+        May be deprecated in the future.
+
+        @param bitmap  width, height, SkColorType, SkAlphaType, and pixel
+                       storage of raster surface
+        @return        SkCanvas that can be used to draw into bitmap
+
+        example: https://fiddle.skia.org/c/@Canvas_copy_const_SkBitmap
+    */
+    explicit SkCanvas(const SkBitmap& bitmap);
+
+#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
+    /** Private.
+     */
+    enum class ColorBehavior {
+        kLegacy, //!< placeholder
+    };
+
+    /** Private. For use by Android framework only.
+
+        @param bitmap    specifies a bitmap for the canvas to draw into
+        @param behavior  specializes this constructor; value is unused
+        @return          SkCanvas that can be used to draw into bitmap
+    */
+    SkCanvas(const SkBitmap& bitmap, ColorBehavior behavior);
+#endif
+
+    /** Constructs a canvas that draws into bitmap.
+        Use props to match the device characteristics, like LCD striping.
+
+        bitmap is copied so that subsequently editing bitmap will not affect
+        constructed SkCanvas.
+
+        @param bitmap  width, height, SkColorType, SkAlphaType,
+                       and pixel storage of raster surface
+        @param props   order and orientation of RGB striping; and whether to use
+                       device independent fonts
+        @return        SkCanvas that can be used to draw into bitmap
+
+        example: https://fiddle.skia.org/c/@Canvas_const_SkBitmap_const_SkSurfaceProps
+    */
+    SkCanvas(const SkBitmap& bitmap, const SkSurfaceProps& props);
+
+    /** Draws saved layers, if any.
+        Frees up resources used by SkCanvas.
+
+        example: https://fiddle.skia.org/c/@Canvas_destructor
+    */
+    virtual ~SkCanvas();
+
+    /** Returns SkImageInfo for SkCanvas. If SkCanvas is not associated with raster surface or
+        GPU surface, returned SkColorType is set to kUnknown_SkColorType.
+
+        @return  dimensions and SkColorType of SkCanvas
+
+        example: https://fiddle.skia.org/c/@Canvas_imageInfo
+    */
+    SkImageInfo imageInfo() const;
+
+    /** Copies SkSurfaceProps, if SkCanvas is associated with raster surface or
+        GPU surface, and returns true. Otherwise, returns false and leave props unchanged.
+
+        @param props  storage for writable SkSurfaceProps
+        @return       true if SkSurfaceProps was copied
+
+        example: https://fiddle.skia.org/c/@Canvas_getProps
+    */
+    bool getProps(SkSurfaceProps* props) const;
+
+    /** Triggers the immediate execution of all pending draw operations.
+        If SkCanvas is associated with GPU surface, resolves all pending GPU operations.
+        If SkCanvas is associated with raster surface, has no effect; raster draw
+        operations are never deferred.
+
+        DEPRECATED: Replace usage with GrDirectContext::flush()
+    */
+    void flush();
+
+    /** Gets the size of the base or root layer in global canvas coordinates. The
+        origin of the base layer is always (0,0). The area available for drawing may be
+        smaller (due to clipping or saveLayer).
+
+        @return  integral width and height of base layer
+
+        example: https://fiddle.skia.org/c/@Canvas_getBaseLayerSize
+    */
+    virtual SkISize getBaseLayerSize() const;
+
+    /** Creates SkSurface matching info and props, and associates it with SkCanvas.
+        Returns nullptr if no match found.
+
+        If props is nullptr, matches SkSurfaceProps in SkCanvas. If props is nullptr and SkCanvas
+        does not have SkSurfaceProps, creates SkSurface with default SkSurfaceProps.
+
+        @param info   width, height, SkColorType, SkAlphaType, and SkColorSpace
+        @param props  SkSurfaceProps to match; may be nullptr to match SkCanvas
+        @return       SkSurface matching info and props, or nullptr if no match is available
+
+        example: https://fiddle.skia.org/c/@Canvas_makeSurface
+    */
+    sk_sp<SkSurface> makeSurface(const SkImageInfo& info, const SkSurfaceProps* props = nullptr);
+
+    /** Returns GPU context of the GPU surface associated with SkCanvas.
+
+        @return  GPU context, if available; nullptr otherwise
+
+        example: https://fiddle.skia.org/c/@Canvas_recordingContext
+     */
+    virtual GrRecordingContext* recordingContext();
+
+    /** Sometimes a canvas is owned by a surface. If it is, getSurface() will return a bare
+     *  pointer to that surface, else this will return nullptr.
+     */
+    SkSurface* getSurface() const;
+
+    /** Returns the pixel base address, SkImageInfo, rowBytes, and origin if the pixels
+        can be read directly. The returned address is only valid
+        while SkCanvas is in scope and unchanged. Any SkCanvas call or SkSurface call
+        may invalidate the returned address and other returned values.
+
+        If pixels are inaccessible, info, rowBytes, and origin are unchanged.
+
+        @param info      storage for writable pixels' SkImageInfo; may be nullptr
+        @param rowBytes  storage for writable pixels' row bytes; may be nullptr
+        @param origin    storage for SkCanvas top layer origin, its top-left corner;
+                         may be nullptr
+        @return          address of pixels, or nullptr if inaccessible
+
+        example: https://fiddle.skia.org/c/@Canvas_accessTopLayerPixels_a
+        example: https://fiddle.skia.org/c/@Canvas_accessTopLayerPixels_b
+    */
+    void* accessTopLayerPixels(SkImageInfo* info, size_t* rowBytes, SkIPoint* origin = nullptr);
+
+    /** Returns custom context that tracks the SkMatrix and clip.
+
+        Use SkRasterHandleAllocator to blend Skia drawing with custom drawing, typically performed
+        by the host platform user interface. The custom context returned is generated by
+        SkRasterHandleAllocator::MakeCanvas, which creates a custom canvas with raster storage for
+        the drawing destination.
+
+        @return  context of custom allocation
+
+        example: https://fiddle.skia.org/c/@Canvas_accessTopRasterHandle
+    */
+    SkRasterHandleAllocator::Handle accessTopRasterHandle() const;
+
+    /** Returns true if SkCanvas has direct access to its pixels.
+
+        Pixels are readable when SkBaseDevice is raster. Pixels are not readable when SkCanvas
+        is returned from GPU surface, returned by SkDocument::beginPage, returned by
+        SkPictureRecorder::beginRecording, or SkCanvas is the base of a utility class
+        like DebugCanvas.
+
+        pixmap is valid only while SkCanvas is in scope and unchanged. Any
+        SkCanvas or SkSurface call may invalidate the pixmap values.
+
+        @param pixmap  storage for pixel state if pixels are readable; otherwise, ignored
+        @return        true if SkCanvas has direct access to pixels
+
+        example: https://fiddle.skia.org/c/@Canvas_peekPixels
+    */
+    bool peekPixels(SkPixmap* pixmap);
+
+    /** Copies SkRect of pixels from SkCanvas into dstPixels. SkMatrix and clip are
+        ignored.
+
+        Source SkRect corners are (srcX, srcY) and (imageInfo().width(), imageInfo().height()).
+        Destination SkRect corners are (0, 0) and (dstInfo.width(), dstInfo.height()).
+        Copies each readable pixel intersecting both rectangles, without scaling,
+        converting to dstInfo.colorType() and dstInfo.alphaType() if required.
+
+        Pixels are readable when SkBaseDevice is raster, or backed by a GPU.
+        Pixels are not readable when SkCanvas is returned by SkDocument::beginPage,
+        returned by SkPictureRecorder::beginRecording, or SkCanvas is the base of a utility
+        class like DebugCanvas.
+
+        The destination pixel storage must be allocated by the caller.
+
+        Pixel values are converted only if SkColorType and SkAlphaType
+        do not match. Only pixels within both source and destination rectangles
+        are copied. dstPixels contents outside SkRect intersection are unchanged.
+
+        Pass negative values for srcX or srcY to offset pixels across or down destination.
+
+        Does not copy, and returns false if:
+        - Source and destination rectangles do not intersect.
+        - SkCanvas pixels could not be converted to dstInfo.colorType() or dstInfo.alphaType().
+        - SkCanvas pixels are not readable; for instance, SkCanvas is document-based.
+        - dstRowBytes is too small to contain one row of pixels.
+
+        @param dstInfo      width, height, SkColorType, and SkAlphaType of dstPixels
+        @param dstPixels    storage for pixels; dstInfo.height() times dstRowBytes, or larger
+        @param dstRowBytes  size of one destination row; dstInfo.width() times pixel size, or larger
+        @param srcX         offset into readable pixels on x-axis; may be negative
+        @param srcY         offset into readable pixels on y-axis; may be negative
+        @return             true if pixels were copied
+    */
+    bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
+                    int srcX, int srcY);
+
+    /** Copies SkRect of pixels from SkCanvas into pixmap. SkMatrix and clip are
+        ignored.
+
+        Source SkRect corners are (srcX, srcY) and (imageInfo().width(), imageInfo().height()).
+        Destination SkRect corners are (0, 0) and (pixmap.width(), pixmap.height()).
+        Copies each readable pixel intersecting both rectangles, without scaling,
+        converting to pixmap.colorType() and pixmap.alphaType() if required.
+
+        Pixels are readable when SkBaseDevice is raster, or backed by a GPU.
+        Pixels are not readable when SkCanvas is returned by SkDocument::beginPage,
+        returned by SkPictureRecorder::beginRecording, or SkCanvas is the base of a utility
+        class like DebugCanvas.
+
+        Caller must allocate pixel storage in pixmap if needed.
+
+        Pixel values are converted only if SkColorType and SkAlphaType
+        do not match. Only pixels within both source and destination SkRect
+        are copied. pixmap pixels contents outside SkRect intersection are unchanged.
+
+        Pass negative values for srcX or srcY to offset pixels across or down pixmap.
+
+        Does not copy, and returns false if:
+        - Source and destination rectangles do not intersect.
+        - SkCanvas pixels could not be converted to pixmap.colorType() or pixmap.alphaType().
+        - SkCanvas pixels are not readable; for instance, SkCanvas is document-based.
+        - SkPixmap pixels could not be allocated.
+        - pixmap.rowBytes() is too small to contain one row of pixels.
+
+        @param pixmap  storage for pixels copied from SkCanvas
+        @param srcX    offset into readable pixels on x-axis; may be negative
+        @param srcY    offset into readable pixels on y-axis; may be negative
+        @return        true if pixels were copied
+
+        example: https://fiddle.skia.org/c/@Canvas_readPixels_2
+    */
+    bool readPixels(const SkPixmap& pixmap, int srcX, int srcY);
+
+    /** Copies SkRect of pixels from SkCanvas into bitmap. SkMatrix and clip are
+        ignored.
+
+        Source SkRect corners are (srcX, srcY) and (imageInfo().width(), imageInfo().height()).
+        Destination SkRect corners are (0, 0) and (bitmap.width(), bitmap.height()).
+        Copies each readable pixel intersecting both rectangles, without scaling,
+        converting to bitmap.colorType() and bitmap.alphaType() if required.
+
+        Pixels are readable when SkBaseDevice is raster, or backed by a GPU.
+        Pixels are not readable when SkCanvas is returned by SkDocument::beginPage,
+        returned by SkPictureRecorder::beginRecording, or SkCanvas is the base of a utility
+        class like DebugCanvas.
+
+        Caller must allocate pixel storage in bitmap if needed.
+
+        SkBitmap values are converted only if SkColorType and SkAlphaType
+        do not match. Only pixels within both source and destination rectangles
+        are copied. SkBitmap pixels outside SkRect intersection are unchanged.
+
+        Pass negative values for srcX or srcY to offset pixels across or down bitmap.
+
+        Does not copy, and returns false if:
+        - Source and destination rectangles do not intersect.
+        - SkCanvas pixels could not be converted to bitmap.colorType() or bitmap.alphaType().
+        - SkCanvas pixels are not readable; for instance, SkCanvas is document-based.
+        - bitmap pixels could not be allocated.
+        - bitmap.rowBytes() is too small to contain one row of pixels.
+
+        @param bitmap  storage for pixels copied from SkCanvas
+        @param srcX    offset into readable pixels on x-axis; may be negative
+        @param srcY    offset into readable pixels on y-axis; may be negative
+        @return        true if pixels were copied
+
+        example: https://fiddle.skia.org/c/@Canvas_readPixels_3
+    */
+    bool readPixels(const SkBitmap& bitmap, int srcX, int srcY);
+
+    /** Copies SkRect from pixels to SkCanvas. SkMatrix and clip are ignored.
+        Source SkRect corners are (0, 0) and (info.width(), info.height()).
+        Destination SkRect corners are (x, y) and
+        (imageInfo().width(), imageInfo().height()).
+
+        Copies each readable pixel intersecting both rectangles, without scaling,
+        converting to imageInfo().colorType() and imageInfo().alphaType() if required.
+
+        Pixels are writable when SkBaseDevice is raster, or backed by a GPU.
+        Pixels are not writable when SkCanvas is returned by SkDocument::beginPage,
+        returned by SkPictureRecorder::beginRecording, or SkCanvas is the base of a utility
+        class like DebugCanvas.
+
+        Pixel values are converted only if SkColorType and SkAlphaType
+        do not match. Only pixels within both source and destination rectangles
+        are copied. SkCanvas pixels outside SkRect intersection are unchanged.
+
+        Pass negative values for x or y to offset pixels to the left or
+        above SkCanvas pixels.
+
+        Does not copy, and returns false if:
+        - Source and destination rectangles do not intersect.
+        - pixels could not be converted to SkCanvas imageInfo().colorType() or
+        imageInfo().alphaType().
+        - SkCanvas pixels are not writable; for instance, SkCanvas is document-based.
+        - rowBytes is too small to contain one row of pixels.
+
+        @param info      width, height, SkColorType, and SkAlphaType of pixels
+        @param pixels    pixels to copy, of size info.height() times rowBytes, or larger
+        @param rowBytes  size of one row of pixels; info.width() times pixel size, or larger
+        @param x         offset into SkCanvas writable pixels on x-axis; may be negative
+        @param y         offset into SkCanvas writable pixels on y-axis; may be negative
+        @return          true if pixels were written to SkCanvas
+
+        example: https://fiddle.skia.org/c/@Canvas_writePixels
+    */
+    bool writePixels(const SkImageInfo& info, const void* pixels, size_t rowBytes, int x, int y);
+
+    /** Copies SkRect from pixels to SkCanvas. SkMatrix and clip are ignored.
+        Source SkRect corners are (0, 0) and (bitmap.width(), bitmap.height()).
+
+        Destination SkRect corners are (x, y) and
+        (imageInfo().width(), imageInfo().height()).
+
+        Copies each readable pixel intersecting both rectangles, without scaling,
+        converting to imageInfo().colorType() and imageInfo().alphaType() if required.
+
+        Pixels are writable when SkBaseDevice is raster, or backed by a GPU.
+        Pixels are not writable when SkCanvas is returned by SkDocument::beginPage,
+        returned by SkPictureRecorder::beginRecording, or SkCanvas is the base of a utility
+        class like DebugCanvas.
+
+        Pixel values are converted only if SkColorType and SkAlphaType
+        do not match. Only pixels within both source and destination rectangles
+        are copied. SkCanvas pixels outside SkRect intersection are unchanged.
+
+        Pass negative values for x or y to offset pixels to the left or
+        above SkCanvas pixels.
+
+        Does not copy, and returns false if:
+        - Source and destination rectangles do not intersect.
+        - bitmap does not have allocated pixels.
+        - bitmap pixels could not be converted to SkCanvas imageInfo().colorType() or
+        imageInfo().alphaType().
+        - SkCanvas pixels are not writable; for instance, SkCanvas is document based.
+        - bitmap pixels are inaccessible; for instance, bitmap wraps a texture.
+
+        @param bitmap  contains pixels copied to SkCanvas
+        @param x       offset into SkCanvas writable pixels on x-axis; may be negative
+        @param y       offset into SkCanvas writable pixels on y-axis; may be negative
+        @return        true if pixels were written to SkCanvas
+
+        example: https://fiddle.skia.org/c/@Canvas_writePixels_2
+        example: https://fiddle.skia.org/c/@State_Stack_a
+        example: https://fiddle.skia.org/c/@State_Stack_b
+    */
+    bool writePixels(const SkBitmap& bitmap, int x, int y);
+
+    /** Saves SkMatrix and clip.
+        Calling restore() discards changes to SkMatrix and clip,
+        restoring the SkMatrix and clip to their state when save() was called.
+
+        SkMatrix may be changed by translate(), scale(), rotate(), skew(), concat(), setMatrix(),
+        and resetMatrix(). Clip may be changed by clipRect(), clipRRect(), clipPath(), clipRegion().
+
+        Saved SkCanvas state is put on a stack; multiple calls to save() should be balance
+        by an equal number of calls to restore().
+
+        Call restoreToCount() with result to restore this and subsequent saves.
+
+        @return  depth of saved stack
+
+        example: https://fiddle.skia.org/c/@Canvas_save
+    */
+    int save();
+
+    /** Saves SkMatrix and clip, and allocates a SkBitmap for subsequent drawing.
+        Calling restore() discards changes to SkMatrix and clip, and draws the SkBitmap.
+
+        SkMatrix may be changed by translate(), scale(), rotate(), skew(), concat(),
+        setMatrix(), and resetMatrix(). Clip may be changed by clipRect(), clipRRect(),
+        clipPath(), clipRegion().
+
+        SkRect bounds suggests but does not define the SkBitmap size. To clip drawing to
+        a specific rectangle, use clipRect().
+
+        Optional SkPaint paint applies alpha, SkColorFilter, SkImageFilter, and
+        SkBlendMode when restore() is called.
+
+        Call restoreToCount() with returned value to restore this and subsequent saves.
+
+        @param bounds  hint to limit the size of the layer; may be nullptr
+        @param paint   graphics state for layer; may be nullptr
+        @return        depth of saved stack
+
+        example: https://fiddle.skia.org/c/@Canvas_saveLayer
+        example: https://fiddle.skia.org/c/@Canvas_saveLayer_4
+    */
+    int saveLayer(const SkRect* bounds, const SkPaint* paint);
+
+    /** Saves SkMatrix and clip, and allocates a SkBitmap for subsequent drawing.
+        Calling restore() discards changes to SkMatrix and clip, and draws the SkBitmap.
+
+        SkMatrix may be changed by translate(), scale(), rotate(), skew(), concat(),
+        setMatrix(), and resetMatrix(). Clip may be changed by clipRect(), clipRRect(),
+        clipPath(), clipRegion().
+
+        SkRect bounds suggests but does not define the layer size. To clip drawing to
+        a specific rectangle, use clipRect().
+
+        Optional SkPaint paint applies alpha, SkColorFilter, SkImageFilter, and
+        SkBlendMode when restore() is called.
+
+        Call restoreToCount() with returned value to restore this and subsequent saves.
+
+        @param bounds  hint to limit the size of layer; may be nullptr
+        @param paint   graphics state for layer; may be nullptr
+        @return        depth of saved stack
+    */
+    int saveLayer(const SkRect& bounds, const SkPaint* paint) {
+        return this->saveLayer(&bounds, paint);
+    }
+
+    /** Saves SkMatrix and clip, and allocates SkBitmap for subsequent drawing.
+
+        Calling restore() discards changes to SkMatrix and clip,
+        and blends layer with alpha opacity onto prior layer.
+
+        SkMatrix may be changed by translate(), scale(), rotate(), skew(), concat(),
+        setMatrix(), and resetMatrix(). Clip may be changed by clipRect(), clipRRect(),
+        clipPath(), clipRegion().
+
+        SkRect bounds suggests but does not define layer size. To clip drawing to
+        a specific rectangle, use clipRect().
+
+        alpha of zero is fully transparent, 255 is fully opaque.
+
+        Call restoreToCount() with returned value to restore this and subsequent saves.
+
+        @param bounds  hint to limit the size of layer; may be nullptr
+        @param alpha   opacity of layer
+        @return        depth of saved stack
+
+        example: https://fiddle.skia.org/c/@Canvas_saveLayerAlpha
+    */
+    int saveLayerAlpha(const SkRect* bounds, U8CPU alpha);
+
+    /** \enum SkCanvas::SaveLayerFlagsSet
+        SaveLayerFlags provides options that may be used in any combination in SaveLayerRec,
+        defining how layer allocated by saveLayer() operates. It may be set to zero,
+        kPreserveLCDText_SaveLayerFlag, kInitWithPrevious_SaveLayerFlag, or both flags.
+    */
+    enum SaveLayerFlagsSet {
+        kPreserveLCDText_SaveLayerFlag  = 1 << 1,
+        kInitWithPrevious_SaveLayerFlag = 1 << 2, //!< initializes with previous contents
+        // instead of matching previous layer's colortype, use F16
+        kF16ColorType                   = 1 << 4,
+    };
+
+    typedef uint32_t SaveLayerFlags;
+
+    /** \struct SkCanvas::SaveLayerRec
+        SaveLayerRec contains the state used to create the layer.
+    */
+    struct SaveLayerRec {
+        /** Sets fBounds, fPaint, and fBackdrop to nullptr. Clears fSaveLayerFlags.
+
+            @return  empty SaveLayerRec
+        */
+        SaveLayerRec() {}
+
+        /** Sets fBounds, fPaint, and fSaveLayerFlags; sets fBackdrop to nullptr.
+
+            @param bounds          layer dimensions; may be nullptr
+            @param paint           applied to layer when overlaying prior layer; may be nullptr
+            @param saveLayerFlags  SaveLayerRec options to modify layer
+            @return                SaveLayerRec with empty fBackdrop
+        */
+        SaveLayerRec(const SkRect* bounds, const SkPaint* paint, SaveLayerFlags saveLayerFlags = 0)
+            : SaveLayerRec(bounds, paint, nullptr, 1.f, saveLayerFlags) {}
+
+        /** Sets fBounds, fPaint, fBackdrop, and fSaveLayerFlags.
+
+            @param bounds          layer dimensions; may be nullptr
+            @param paint           applied to layer when overlaying prior layer;
+                                   may be nullptr
+            @param backdrop        If not null, this causes the current layer to be filtered by
+                                   backdrop, and then drawn into the new layer
+                                   (respecting the current clip).
+                                   If null, the new layer is initialized with transparent-black.
+            @param saveLayerFlags  SaveLayerRec options to modify layer
+            @return                SaveLayerRec fully specified
+        */
+        SaveLayerRec(const SkRect* bounds, const SkPaint* paint, const SkImageFilter* backdrop,
+                     SaveLayerFlags saveLayerFlags)
+            : SaveLayerRec(bounds, paint, backdrop, 1.f, saveLayerFlags) {}
+
+        /** hints at layer size limit */
+        const SkRect*        fBounds         = nullptr;
+
+        /** modifies overlay */
+        const SkPaint*       fPaint          = nullptr;
+
+        /**
+         *  If not null, this triggers the same initialization behavior as setting
+         *  kInitWithPrevious_SaveLayerFlag on fSaveLayerFlags: the current layer is copied into
+         *  the new layer, rather than initializing the new layer with transparent-black.
+         *  This is then filtered by fBackdrop (respecting the current clip).
+         */
+        const SkImageFilter* fBackdrop       = nullptr;
+
+        /** preserves LCD text, creates with prior layer contents */
+        SaveLayerFlags       fSaveLayerFlags = 0;
+
+    private:
+        friend class SkCanvas;
+        friend class SkCanvasPriv;
+
+        SaveLayerRec(const SkRect* bounds, const SkPaint* paint, const SkImageFilter* backdrop,
+                     SkScalar backdropScale, SaveLayerFlags saveLayerFlags)
+            : fBounds(bounds)
+            , fPaint(paint)
+            , fBackdrop(backdrop)
+            , fSaveLayerFlags(saveLayerFlags)
+            , fExperimentalBackdropScale(backdropScale) {}
+
+        // Relative scale factor that the image content used to initialize the layer when the
+        // kInitFromPrevious flag or a backdrop filter is used.
+        SkScalar             fExperimentalBackdropScale = 1.f;
+    };
+
+    /** Saves SkMatrix and clip, and allocates SkBitmap for subsequent drawing.
+
+        Calling restore() discards changes to SkMatrix and clip,
+        and blends SkBitmap with alpha opacity onto the prior layer.
+
+        SkMatrix may be changed by translate(), scale(), rotate(), skew(), concat(),
+        setMatrix(), and resetMatrix(). Clip may be changed by clipRect(), clipRRect(),
+        clipPath(), clipRegion().
+
+        SaveLayerRec contains the state used to create the layer.
+
+        Call restoreToCount() with returned value to restore this and subsequent saves.
+
+        @param layerRec  layer state
+        @return          depth of save state stack before this call was made.
+
+        example: https://fiddle.skia.org/c/@Canvas_saveLayer_3
+    */
+    int saveLayer(const SaveLayerRec& layerRec);
+
+    /** Removes changes to SkMatrix and clip since SkCanvas state was
+        last saved. The state is removed from the stack.
+
+        Does nothing if the stack is empty.
+
+        example: https://fiddle.skia.org/c/@AutoCanvasRestore_restore
+
+        example: https://fiddle.skia.org/c/@Canvas_restore
+    */
+    void restore();
+
+    /** Returns the number of saved states, each containing: SkMatrix and clip.
+        Equals the number of save() calls less the number of restore() calls plus one.
+        The save count of a new canvas is one.
+
+        @return  depth of save state stack
+
+        example: https://fiddle.skia.org/c/@Canvas_getSaveCount
+    */
+    int getSaveCount() const;
+
+    /** Restores state to SkMatrix and clip values when save(), saveLayer(),
+        saveLayerPreserveLCDTextRequests(), or saveLayerAlpha() returned saveCount.
+
+        Does nothing if saveCount is greater than state stack count.
+        Restores state to initial values if saveCount is less than or equal to one.
+
+        @param saveCount  depth of state stack to restore
+
+        example: https://fiddle.skia.org/c/@Canvas_restoreToCount
+    */
+    void restoreToCount(int saveCount);
+
+    /** Translates SkMatrix by dx along the x-axis and dy along the y-axis.
+
+        Mathematically, replaces SkMatrix with a translation matrix
+        premultiplied with SkMatrix.
+
+        This has the effect of moving the drawing by (dx, dy) before transforming
+        the result with SkMatrix.
+
+        @param dx  distance to translate on x-axis
+        @param dy  distance to translate on y-axis
+
+        example: https://fiddle.skia.org/c/@Canvas_translate
+    */
+    void translate(SkScalar dx, SkScalar dy);
+
+    /** Scales SkMatrix by sx on the x-axis and sy on the y-axis.
+
+        Mathematically, replaces SkMatrix with a scale matrix
+        premultiplied with SkMatrix.
+
+        This has the effect of scaling the drawing by (sx, sy) before transforming
+        the result with SkMatrix.
+
+        @param sx  amount to scale on x-axis
+        @param sy  amount to scale on y-axis
+
+        example: https://fiddle.skia.org/c/@Canvas_scale
+    */
+    void scale(SkScalar sx, SkScalar sy);
+
+    /** Rotates SkMatrix by degrees. Positive degrees rotates clockwise.
+
+        Mathematically, replaces SkMatrix with a rotation matrix
+        premultiplied with SkMatrix.
+
+        This has the effect of rotating the drawing by degrees before transforming
+        the result with SkMatrix.
+
+        @param degrees  amount to rotate, in degrees
+
+        example: https://fiddle.skia.org/c/@Canvas_rotate
+    */
+    void rotate(SkScalar degrees);
+
+    /** Rotates SkMatrix by degrees about a point at (px, py). Positive degrees rotates
+        clockwise.
+
+        Mathematically, constructs a rotation matrix; premultiplies the rotation matrix by
+        a translation matrix; then replaces SkMatrix with the resulting matrix
+        premultiplied with SkMatrix.
+
+        This has the effect of rotating the drawing about a given point before
+        transforming the result with SkMatrix.
+
+        @param degrees  amount to rotate, in degrees
+        @param px       x-axis value of the point to rotate about
+        @param py       y-axis value of the point to rotate about
+
+        example: https://fiddle.skia.org/c/@Canvas_rotate_2
+    */
+    void rotate(SkScalar degrees, SkScalar px, SkScalar py);
+
+    /** Skews SkMatrix by sx on the x-axis and sy on the y-axis. A positive value of sx
+        skews the drawing right as y-axis values increase; a positive value of sy skews
+        the drawing down as x-axis values increase.
+
+        Mathematically, replaces SkMatrix with a skew matrix premultiplied with SkMatrix.
+
+        This has the effect of skewing the drawing by (sx, sy) before transforming
+        the result with SkMatrix.
+
+        @param sx  amount to skew on x-axis
+        @param sy  amount to skew on y-axis
+
+        example: https://fiddle.skia.org/c/@Canvas_skew
+    */
+    void skew(SkScalar sx, SkScalar sy);
+
+    /** Replaces SkMatrix with matrix premultiplied with existing SkMatrix.
+
+        This has the effect of transforming the drawn geometry by matrix, before
+        transforming the result with existing SkMatrix.
+
+        @param matrix  matrix to premultiply with existing SkMatrix
+
+        example: https://fiddle.skia.org/c/@Canvas_concat
+    */
+    void concat(const SkMatrix& matrix);
+    void concat(const SkM44&);
+
+    /** Replaces SkMatrix with matrix.
+        Unlike concat(), any prior matrix state is overwritten.
+
+        @param matrix  matrix to copy, replacing existing SkMatrix
+
+        example: https://fiddle.skia.org/c/@Canvas_setMatrix
+    */
+    void setMatrix(const SkM44& matrix);
+
+    // DEPRECATED -- use SkM44 version
+    void setMatrix(const SkMatrix& matrix);
+
+    /** Sets SkMatrix to the identity matrix.
+        Any prior matrix state is overwritten.
+
+        example: https://fiddle.skia.org/c/@Canvas_resetMatrix
+    */
+    void resetMatrix();
+
+    /** Replaces clip with the intersection or difference of clip and rect,
+        with an aliased or anti-aliased clip edge. rect is transformed by SkMatrix
+        before it is combined with clip.
+
+        @param rect         SkRect to combine with clip
+        @param op           SkClipOp to apply to clip
+        @param doAntiAlias  true if clip is to be anti-aliased
+
+        example: https://fiddle.skia.org/c/@Canvas_clipRect
+    */
+    void clipRect(const SkRect& rect, SkClipOp op, bool doAntiAlias);
+
+    /** Replaces clip with the intersection or difference of clip and rect.
+        Resulting clip is aliased; pixels are fully contained by the clip.
+        rect is transformed by SkMatrix before it is combined with clip.
+
+        @param rect  SkRect to combine with clip
+        @param op    SkClipOp to apply to clip
+    */
+    void clipRect(const SkRect& rect, SkClipOp op) {
+        this->clipRect(rect, op, false);
+    }
+
+    /** Replaces clip with the intersection of clip and rect.
+        Resulting clip is aliased; pixels are fully contained by the clip.
+        rect is transformed by SkMatrix
+        before it is combined with clip.
+
+        @param rect         SkRect to combine with clip
+        @param doAntiAlias  true if clip is to be anti-aliased
+    */
+    void clipRect(const SkRect& rect, bool doAntiAlias = false) {
+        this->clipRect(rect, SkClipOp::kIntersect, doAntiAlias);
+    }
+
+    void clipIRect(const SkIRect& irect, SkClipOp op = SkClipOp::kIntersect) {
+        this->clipRect(SkRect::Make(irect), op, false);
+    }
+
+    /** Sets the maximum clip rectangle, which can be set by clipRect(), clipRRect() and
+        clipPath() and intersect the current clip with the specified rect.
+        The maximum clip affects only future clipping operations; it is not retroactive.
+        The clip restriction is not recorded in pictures.
+
+        Pass an empty rect to disable maximum clip.
+        This private API is for use by Android framework only.
+
+        DEPRECATED: Replace usage with SkAndroidFrameworkUtils::replaceClip()
+
+        @param rect  maximum allowed clip in device coordinates
+    */
+    void androidFramework_setDeviceClipRestriction(const SkIRect& rect);
+
+    /** Replaces clip with the intersection or difference of clip and rrect,
+        with an aliased or anti-aliased clip edge.
+        rrect is transformed by SkMatrix
+        before it is combined with clip.
+
+        @param rrect        SkRRect to combine with clip
+        @param op           SkClipOp to apply to clip
+        @param doAntiAlias  true if clip is to be anti-aliased
+
+        example: https://fiddle.skia.org/c/@Canvas_clipRRect
+    */
+    void clipRRect(const SkRRect& rrect, SkClipOp op, bool doAntiAlias);
+
+    /** Replaces clip with the intersection or difference of clip and rrect.
+        Resulting clip is aliased; pixels are fully contained by the clip.
+        rrect is transformed by SkMatrix before it is combined with clip.
+
+        @param rrect  SkRRect to combine with clip
+        @param op     SkClipOp to apply to clip
+    */
+    void clipRRect(const SkRRect& rrect, SkClipOp op) {
+        this->clipRRect(rrect, op, false);
+    }
+
+    /** Replaces clip with the intersection of clip and rrect,
+        with an aliased or anti-aliased clip edge.
+        rrect is transformed by SkMatrix before it is combined with clip.
+
+        @param rrect        SkRRect to combine with clip
+        @param doAntiAlias  true if clip is to be anti-aliased
+    */
+    void clipRRect(const SkRRect& rrect, bool doAntiAlias = false) {
+        this->clipRRect(rrect, SkClipOp::kIntersect, doAntiAlias);
+    }
+
+    /** Replaces clip with the intersection or difference of clip and path,
+        with an aliased or anti-aliased clip edge. SkPath::FillType determines if path
+        describes the area inside or outside its contours; and if path contour overlaps
+        itself or another path contour, whether the overlaps form part of the area.
+        path is transformed by SkMatrix before it is combined with clip.
+
+        @param path         SkPath to combine with clip
+        @param op           SkClipOp to apply to clip
+        @param doAntiAlias  true if clip is to be anti-aliased
+
+        example: https://fiddle.skia.org/c/@Canvas_clipPath
+    */
+    void clipPath(const SkPath& path, SkClipOp op, bool doAntiAlias);
+
+    /** Replaces clip with the intersection or difference of clip and path.
+        Resulting clip is aliased; pixels are fully contained by the clip.
+        SkPath::FillType determines if path
+        describes the area inside or outside its contours; and if path contour overlaps
+        itself or another path contour, whether the overlaps form part of the area.
+        path is transformed by SkMatrix
+        before it is combined with clip.
+
+        @param path  SkPath to combine with clip
+        @param op    SkClipOp to apply to clip
+    */
+    void clipPath(const SkPath& path, SkClipOp op) {
+        this->clipPath(path, op, false);
+    }
+
+    /** Replaces clip with the intersection of clip and path.
+        Resulting clip is aliased; pixels are fully contained by the clip.
+        SkPath::FillType determines if path
+        describes the area inside or outside its contours; and if path contour overlaps
+        itself or another path contour, whether the overlaps form part of the area.
+        path is transformed by SkMatrix before it is combined with clip.
+
+        @param path         SkPath to combine with clip
+        @param doAntiAlias  true if clip is to be anti-aliased
+    */
+    void clipPath(const SkPath& path, bool doAntiAlias = false) {
+        this->clipPath(path, SkClipOp::kIntersect, doAntiAlias);
+    }
+
+    void clipShader(sk_sp<SkShader>, SkClipOp = SkClipOp::kIntersect);
+
+    /** Replaces clip with the intersection or difference of clip and SkRegion deviceRgn.
+        Resulting clip is aliased; pixels are fully contained by the clip.
+        deviceRgn is unaffected by SkMatrix.
+
+        @param deviceRgn  SkRegion to combine with clip
+        @param op         SkClipOp to apply to clip
+
+        example: https://fiddle.skia.org/c/@Canvas_clipRegion
+    */
+    void clipRegion(const SkRegion& deviceRgn, SkClipOp op = SkClipOp::kIntersect);
+
+    /** Returns true if SkRect rect, transformed by SkMatrix, can be quickly determined to be
+        outside of clip. May return false even though rect is outside of clip.
+
+        Use to check if an area to be drawn is clipped out, to skip subsequent draw calls.
+
+        @param rect  SkRect to compare with clip
+        @return      true if rect, transformed by SkMatrix, does not intersect clip
+
+        example: https://fiddle.skia.org/c/@Canvas_quickReject
+    */
+    bool quickReject(const SkRect& rect) const;
+
+    /** Returns true if path, transformed by SkMatrix, can be quickly determined to be
+        outside of clip. May return false even though path is outside of clip.
+
+        Use to check if an area to be drawn is clipped out, to skip subsequent draw calls.
+
+        @param path  SkPath to compare with clip
+        @return      true if path, transformed by SkMatrix, does not intersect clip
+
+        example: https://fiddle.skia.org/c/@Canvas_quickReject_2
+    */
+    bool quickReject(const SkPath& path) const;
+
+    /** Returns bounds of clip, transformed by inverse of SkMatrix. If clip is empty,
+        return SkRect::MakeEmpty, where all SkRect sides equal zero.
+
+        SkRect returned is outset by one to account for partial pixel coverage if clip
+        is anti-aliased.
+
+        @return  bounds of clip in local coordinates
+
+        example: https://fiddle.skia.org/c/@Canvas_getLocalClipBounds
+    */
+    SkRect getLocalClipBounds() const;
+
+    /** Returns bounds of clip, transformed by inverse of SkMatrix. If clip is empty,
+        return false, and set bounds to SkRect::MakeEmpty, where all SkRect sides equal zero.
+
+        bounds is outset by one to account for partial pixel coverage if clip
+        is anti-aliased.
+
+        @param bounds  SkRect of clip in local coordinates
+        @return        true if clip bounds is not empty
+    */
+    bool getLocalClipBounds(SkRect* bounds) const {
+        *bounds = this->getLocalClipBounds();
+        return !bounds->isEmpty();
+    }
+
+    /** Returns SkIRect bounds of clip, unaffected by SkMatrix. If clip is empty,
+        return SkRect::MakeEmpty, where all SkRect sides equal zero.
+
+        Unlike getLocalClipBounds(), returned SkIRect is not outset.
+
+        @return  bounds of clip in SkBaseDevice coordinates
+
+        example: https://fiddle.skia.org/c/@Canvas_getDeviceClipBounds
+    */
+    SkIRect getDeviceClipBounds() const;
+
+    /** Returns SkIRect bounds of clip, unaffected by SkMatrix. If clip is empty,
+        return false, and set bounds to SkRect::MakeEmpty, where all SkRect sides equal zero.
+
+        Unlike getLocalClipBounds(), bounds is not outset.
+
+        @param bounds  SkRect of clip in device coordinates
+        @return        true if clip bounds is not empty
+    */
+    bool getDeviceClipBounds(SkIRect* bounds) const {
+        *bounds = this->getDeviceClipBounds();
+        return !bounds->isEmpty();
+    }
+
+    /** Fills clip with color color.
+        mode determines how ARGB is combined with destination.
+
+        @param color  unpremultiplied ARGB
+        @param mode   SkBlendMode used to combine source color and destination
+
+        example: https://fiddle.skia.org/c/@Canvas_drawColor
+    */
+    void drawColor(SkColor color, SkBlendMode mode = SkBlendMode::kSrcOver) {
+        this->drawColor(SkColor4f::FromColor(color), mode);
+    }
+
+    /** Fills clip with color color.
+        mode determines how ARGB is combined with destination.
+
+        @param color  SkColor4f representing unpremultiplied color.
+        @param mode   SkBlendMode used to combine source color and destination
+    */
+    void drawColor(const SkColor4f& color, SkBlendMode mode = SkBlendMode::kSrcOver);
+
+    /** Fills clip with color color using SkBlendMode::kSrc.
+        This has the effect of replacing all pixels contained by clip with color.
+
+        @param color  unpremultiplied ARGB
+    */
+    void clear(SkColor color) {
+        this->clear(SkColor4f::FromColor(color));
+    }
+
+    /** Fills clip with color color using SkBlendMode::kSrc.
+        This has the effect of replacing all pixels contained by clip with color.
+
+        @param color  SkColor4f representing unpremultiplied color.
+    */
+    void clear(const SkColor4f& color) {
+        this->drawColor(color, SkBlendMode::kSrc);
+    }
+
+    /** Makes SkCanvas contents undefined. Subsequent calls that read SkCanvas pixels,
+        such as drawing with SkBlendMode, return undefined results. discard() does
+        not change clip or SkMatrix.
+
+        discard() may do nothing, depending on the implementation of SkSurface or SkBaseDevice
+        that created SkCanvas.
+
+        discard() allows optimized performance on subsequent draws by removing
+        cached data associated with SkSurface or SkBaseDevice.
+        It is not necessary to call discard() once done with SkCanvas;
+        any cached data is deleted when owning SkSurface or SkBaseDevice is deleted.
+    */
+    void discard() { this->onDiscard(); }
+
+    /** Fills clip with SkPaint paint. SkPaint components, SkShader,
+        SkColorFilter, SkImageFilter, and SkBlendMode affect drawing;
+        SkMaskFilter and SkPathEffect in paint are ignored.
+
+        @param paint  graphics state used to fill SkCanvas
+
+        example: https://fiddle.skia.org/c/@Canvas_drawPaint
+    */
+    void drawPaint(const SkPaint& paint);
+
+    /** \enum SkCanvas::PointMode
+        Selects if an array of points are drawn as discrete points, as lines, or as
+        an open polygon.
+    */
+    enum PointMode {
+        kPoints_PointMode,  //!< draw each point separately
+        kLines_PointMode,   //!< draw each pair of points as a line segment
+        kPolygon_PointMode, //!< draw the array of points as a open polygon
+    };
+
+    /** Draws pts using clip, SkMatrix and SkPaint paint.
+        count is the number of points; if count is less than one, has no effect.
+        mode may be one of: kPoints_PointMode, kLines_PointMode, or kPolygon_PointMode.
+
+        If mode is kPoints_PointMode, the shape of point drawn depends on paint
+        SkPaint::Cap. If paint is set to SkPaint::kRound_Cap, each point draws a
+        circle of diameter SkPaint stroke width. If paint is set to SkPaint::kSquare_Cap
+        or SkPaint::kButt_Cap, each point draws a square of width and height
+        SkPaint stroke width.
+
+        If mode is kLines_PointMode, each pair of points draws a line segment.
+        One line is drawn for every two points; each point is used once. If count is odd,
+        the final point is ignored.
+
+        If mode is kPolygon_PointMode, each adjacent pair of points draws a line segment.
+        count minus one lines are drawn; the first and last point are used once.
+
+        Each line segment respects paint SkPaint::Cap and SkPaint stroke width.
+        SkPaint::Style is ignored, as if were set to SkPaint::kStroke_Style.
+
+        Always draws each element one at a time; is not affected by
+        SkPaint::Join, and unlike drawPath(), does not create a mask from all points
+        and lines before drawing.
+
+        @param mode   whether pts draws points or lines
+        @param count  number of points in the array
+        @param pts    array of points to draw
+        @param paint  stroke, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawPoints
+    */
+    void drawPoints(PointMode mode, size_t count, const SkPoint pts[], const SkPaint& paint);
+
+    /** Draws point at (x, y) using clip, SkMatrix and SkPaint paint.
+
+        The shape of point drawn depends on paint SkPaint::Cap.
+        If paint is set to SkPaint::kRound_Cap, draw a circle of diameter
+        SkPaint stroke width. If paint is set to SkPaint::kSquare_Cap or SkPaint::kButt_Cap,
+        draw a square of width and height SkPaint stroke width.
+        SkPaint::Style is ignored, as if were set to SkPaint::kStroke_Style.
+
+        @param x      left edge of circle or square
+        @param y      top edge of circle or square
+        @param paint  stroke, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawPoint
+    */
+    void drawPoint(SkScalar x, SkScalar y, const SkPaint& paint);
+
+    /** Draws point p using clip, SkMatrix and SkPaint paint.
+
+        The shape of point drawn depends on paint SkPaint::Cap.
+        If paint is set to SkPaint::kRound_Cap, draw a circle of diameter
+        SkPaint stroke width. If paint is set to SkPaint::kSquare_Cap or SkPaint::kButt_Cap,
+        draw a square of width and height SkPaint stroke width.
+        SkPaint::Style is ignored, as if were set to SkPaint::kStroke_Style.
+
+        @param p      top-left edge of circle or square
+        @param paint  stroke, blend, color, and so on, used to draw
+    */
+    void drawPoint(SkPoint p, const SkPaint& paint) {
+        this->drawPoint(p.x(), p.y(), paint);
+    }
+
+    /** Draws line segment from (x0, y0) to (x1, y1) using clip, SkMatrix, and SkPaint paint.
+        In paint: SkPaint stroke width describes the line thickness;
+        SkPaint::Cap draws the end rounded or square;
+        SkPaint::Style is ignored, as if were set to SkPaint::kStroke_Style.
+
+        @param x0     start of line segment on x-axis
+        @param y0     start of line segment on y-axis
+        @param x1     end of line segment on x-axis
+        @param y1     end of line segment on y-axis
+        @param paint  stroke, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawLine
+    */
+    void drawLine(SkScalar x0, SkScalar y0, SkScalar x1, SkScalar y1, const SkPaint& paint);
+
+    /** Draws line segment from p0 to p1 using clip, SkMatrix, and SkPaint paint.
+        In paint: SkPaint stroke width describes the line thickness;
+        SkPaint::Cap draws the end rounded or square;
+        SkPaint::Style is ignored, as if were set to SkPaint::kStroke_Style.
+
+        @param p0     start of line segment
+        @param p1     end of line segment
+        @param paint  stroke, blend, color, and so on, used to draw
+    */
+    void drawLine(SkPoint p0, SkPoint p1, const SkPaint& paint) {
+        this->drawLine(p0.x(), p0.y(), p1.x(), p1.y(), paint);
+    }
+
+    /** Draws SkRect rect using clip, SkMatrix, and SkPaint paint.
+        In paint: SkPaint::Style determines if rectangle is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness, and
+        SkPaint::Join draws the corners rounded or square.
+
+        @param rect   rectangle to draw
+        @param paint  stroke or fill, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawRect
+    */
+    void drawRect(const SkRect& rect, const SkPaint& paint);
+
+    /** Draws SkIRect rect using clip, SkMatrix, and SkPaint paint.
+        In paint: SkPaint::Style determines if rectangle is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness, and
+        SkPaint::Join draws the corners rounded or square.
+
+        @param rect   rectangle to draw
+        @param paint  stroke or fill, blend, color, and so on, used to draw
+    */
+    void drawIRect(const SkIRect& rect, const SkPaint& paint) {
+        SkRect r;
+        r.set(rect);    // promotes the ints to scalars
+        this->drawRect(r, paint);
+    }
+
+    /** Draws SkRegion region using clip, SkMatrix, and SkPaint paint.
+        In paint: SkPaint::Style determines if rectangle is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness, and
+        SkPaint::Join draws the corners rounded or square.
+
+        @param region  region to draw
+        @param paint   SkPaint stroke or fill, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawRegion
+    */
+    void drawRegion(const SkRegion& region, const SkPaint& paint);
+
+    /** Draws oval oval using clip, SkMatrix, and SkPaint.
+        In paint: SkPaint::Style determines if oval is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness.
+
+        @param oval   SkRect bounds of oval
+        @param paint  SkPaint stroke or fill, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawOval
+    */
+    void drawOval(const SkRect& oval, const SkPaint& paint);
+
+    /** Draws SkRRect rrect using clip, SkMatrix, and SkPaint paint.
+        In paint: SkPaint::Style determines if rrect is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness.
+
+        rrect may represent a rectangle, circle, oval, uniformly rounded rectangle, or
+        may have any combination of positive non-square radii for the four corners.
+
+        @param rrect  SkRRect with up to eight corner radii to draw
+        @param paint  SkPaint stroke or fill, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawRRect
+    */
+    void drawRRect(const SkRRect& rrect, const SkPaint& paint);
+
+    /** Draws SkRRect outer and inner
+        using clip, SkMatrix, and SkPaint paint.
+        outer must contain inner or the drawing is undefined.
+        In paint: SkPaint::Style determines if SkRRect is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness.
+        If stroked and SkRRect corner has zero length radii, SkPaint::Join can
+        draw corners rounded or square.
+
+        GPU-backed platforms optimize drawing when both outer and inner are
+        concave and outer contains inner. These platforms may not be able to draw
+        SkPath built with identical data as fast.
+
+        @param outer  SkRRect outer bounds to draw
+        @param inner  SkRRect inner bounds to draw
+        @param paint  SkPaint stroke or fill, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawDRRect_a
+        example: https://fiddle.skia.org/c/@Canvas_drawDRRect_b
+    */
+    void drawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint& paint);
+
+    /** Draws circle at (cx, cy) with radius using clip, SkMatrix, and SkPaint paint.
+        If radius is zero or less, nothing is drawn.
+        In paint: SkPaint::Style determines if circle is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness.
+
+        @param cx      circle center on the x-axis
+        @param cy      circle center on the y-axis
+        @param radius  half the diameter of circle
+        @param paint   SkPaint stroke or fill, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawCircle
+    */
+    void drawCircle(SkScalar cx, SkScalar cy, SkScalar radius, const SkPaint& paint);
+
+    /** Draws circle at center with radius using clip, SkMatrix, and SkPaint paint.
+        If radius is zero or less, nothing is drawn.
+        In paint: SkPaint::Style determines if circle is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness.
+
+        @param center  circle center
+        @param radius  half the diameter of circle
+        @param paint   SkPaint stroke or fill, blend, color, and so on, used to draw
+    */
+    void drawCircle(SkPoint center, SkScalar radius, const SkPaint& paint) {
+        this->drawCircle(center.x(), center.y(), radius, paint);
+    }
+
+    /** Draws arc using clip, SkMatrix, and SkPaint paint.
+
+        Arc is part of oval bounded by oval, sweeping from startAngle to startAngle plus
+        sweepAngle. startAngle and sweepAngle are in degrees.
+
+        startAngle of zero places start point at the right middle edge of oval.
+        A positive sweepAngle places arc end point clockwise from start point;
+        a negative sweepAngle places arc end point counterclockwise from start point.
+        sweepAngle may exceed 360 degrees, a full circle.
+        If useCenter is true, draw a wedge that includes lines from oval
+        center to arc end points. If useCenter is false, draw arc between end points.
+
+        If SkRect oval is empty or sweepAngle is zero, nothing is drawn.
+
+        @param oval        SkRect bounds of oval containing arc to draw
+        @param startAngle  angle in degrees where arc begins
+        @param sweepAngle  sweep angle in degrees; positive is clockwise
+        @param useCenter   if true, include the center of the oval
+        @param paint       SkPaint stroke or fill, blend, color, and so on, used to draw
+    */
+    void drawArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle,
+                 bool useCenter, const SkPaint& paint);
+
+    /** Draws SkRRect bounded by SkRect rect, with corner radii (rx, ry) using clip,
+        SkMatrix, and SkPaint paint.
+
+        In paint: SkPaint::Style determines if SkRRect is stroked or filled;
+        if stroked, SkPaint stroke width describes the line thickness.
+        If rx or ry are less than zero, they are treated as if they are zero.
+        If rx plus ry exceeds rect width or rect height, radii are scaled down to fit.
+        If rx and ry are zero, SkRRect is drawn as SkRect and if stroked is affected by
+        SkPaint::Join.
+
+        @param rect   SkRect bounds of SkRRect to draw
+        @param rx     axis length on x-axis of oval describing rounded corners
+        @param ry     axis length on y-axis of oval describing rounded corners
+        @param paint  stroke, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawRoundRect
+    */
+    void drawRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, const SkPaint& paint);
+
+    /** Draws SkPath path using clip, SkMatrix, and SkPaint paint.
+        SkPath contains an array of path contour, each of which may be open or closed.
+
+        In paint: SkPaint::Style determines if SkRRect is stroked or filled:
+        if filled, SkPath::FillType determines whether path contour describes inside or
+        outside of fill; if stroked, SkPaint stroke width describes the line thickness,
+        SkPaint::Cap describes line ends, and SkPaint::Join describes how
+        corners are drawn.
+
+        @param path   SkPath to draw
+        @param paint  stroke, blend, color, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawPath
+    */
+    void drawPath(const SkPath& path, const SkPaint& paint);
+
+    void drawImage(const SkImage* image, SkScalar left, SkScalar top) {
+        this->drawImage(image, left, top, SkSamplingOptions(), nullptr);
+    }
+    void drawImage(const sk_sp<SkImage>& image, SkScalar left, SkScalar top) {
+        this->drawImage(image.get(), left, top, SkSamplingOptions(), nullptr);
+    }
+
+    /** \enum SkCanvas::SrcRectConstraint
+        SrcRectConstraint controls the behavior at the edge of source SkRect,
+        provided to drawImageRect() when there is any filtering. If kStrict is set,
+        then extra code is used to ensure it nevers samples outside of the src-rect.
+    */
+    enum SrcRectConstraint {
+        kStrict_SrcRectConstraint, //!< sample only inside bounds; slower
+        kFast_SrcRectConstraint,   //!< sample outside bounds; faster
+    };
+
+    void drawImage(const SkImage*, SkScalar x, SkScalar y, const SkSamplingOptions&,
+                   const SkPaint* = nullptr);
+    void drawImage(const sk_sp<SkImage>& image, SkScalar x, SkScalar y,
+                   const SkSamplingOptions& sampling, const SkPaint* paint = nullptr) {
+        this->drawImage(image.get(), x, y, sampling, paint);
+    }
+    void drawImageRect(const SkImage*, const SkRect& src, const SkRect& dst,
+                       const SkSamplingOptions&, const SkPaint*, SrcRectConstraint);
+    void drawImageRect(const SkImage*, const SkRect& dst, const SkSamplingOptions&,
+                       const SkPaint* = nullptr);
+    void drawImageRect(const sk_sp<SkImage>& image, const SkRect& src, const SkRect& dst,
+                       const SkSamplingOptions& sampling, const SkPaint* paint,
+                       SrcRectConstraint constraint) {
+        this->drawImageRect(image.get(), src, dst, sampling, paint, constraint);
+    }
+    void drawImageRect(const sk_sp<SkImage>& image, const SkRect& dst,
+                       const SkSamplingOptions& sampling, const SkPaint* paint = nullptr) {
+        this->drawImageRect(image.get(), dst, sampling, paint);
+    }
+
+    /** Draws SkImage image stretched proportionally to fit into SkRect dst.
+        SkIRect center divides the image into nine sections: four sides, four corners, and
+        the center. Corners are unmodified or scaled down proportionately if their sides
+        are larger than dst; center and four sides are scaled to fit remaining space, if any.
+
+        Additionally transform draw using clip, SkMatrix, and optional SkPaint paint.
+
+        If SkPaint paint is supplied, apply SkColorFilter, alpha, SkImageFilter, and
+        SkBlendMode. If image is kAlpha_8_SkColorType, apply SkShader.
+        If paint contains SkMaskFilter, generate mask from image bounds.
+        Any SkMaskFilter on paint is ignored as is paint anti-aliasing state.
+
+        If generated mask extends beyond image bounds, replicate image edge colors, just
+        as SkShader made from SkImage::makeShader with SkShader::kClamp_TileMode set
+        replicates the image edge color when it samples outside of its bounds.
+
+        @param image   SkImage containing pixels, dimensions, and format
+        @param center  SkIRect edge of image corners and sides
+        @param dst     destination SkRect of image to draw to
+        @param filter  what technique to use when sampling the image
+        @param paint   SkPaint containing SkBlendMode, SkColorFilter, SkImageFilter,
+                       and so on; or nullptr
+    */
+    void drawImageNine(const SkImage* image, const SkIRect& center, const SkRect& dst,
+                       SkFilterMode filter, const SkPaint* paint = nullptr);
+
+    /** \struct SkCanvas::Lattice
+        SkCanvas::Lattice divides SkBitmap or SkImage into a rectangular grid.
+        Grid entries on even columns and even rows are fixed; these entries are
+        always drawn at their original size if the destination is large enough.
+        If the destination side is too small to hold the fixed entries, all fixed
+        entries are proportionately scaled down to fit.
+        The grid entries not on even columns and rows are scaled to fit the
+        remaining space, if any.
+    */
+    struct Lattice {
+
+        /** \enum SkCanvas::Lattice::RectType
+            Optional setting per rectangular grid entry to make it transparent,
+            or to fill the grid entry with a color.
+        */
+        enum RectType : uint8_t {
+            kDefault     = 0, //!< draws SkBitmap into lattice rectangle
+            kTransparent,     //!< skips lattice rectangle by making it transparent
+            kFixedColor,      //!< draws one of fColors into lattice rectangle
+        };
+
+        const int*      fXDivs;     //!< x-axis values dividing bitmap
+        const int*      fYDivs;     //!< y-axis values dividing bitmap
+        const RectType* fRectTypes; //!< array of fill types
+        int             fXCount;    //!< number of x-coordinates
+        int             fYCount;    //!< number of y-coordinates
+        const SkIRect*  fBounds;    //!< source bounds to draw from
+        const SkColor*  fColors;    //!< array of colors
+    };
+
+    /** Draws SkImage image stretched proportionally to fit into SkRect dst.
+
+        SkCanvas::Lattice lattice divides image into a rectangular grid.
+        Each intersection of an even-numbered row and column is fixed;
+        fixed lattice elements never scale larger than their initial
+        size and shrink proportionately when all fixed elements exceed the bitmap
+        dimension. All other grid elements scale to fill the available space, if any.
+
+        Additionally transform draw using clip, SkMatrix, and optional SkPaint paint.
+
+        If SkPaint paint is supplied, apply SkColorFilter, alpha, SkImageFilter, and
+        SkBlendMode. If image is kAlpha_8_SkColorType, apply SkShader.
+        If paint contains SkMaskFilter, generate mask from image bounds.
+        Any SkMaskFilter on paint is ignored as is paint anti-aliasing state.
+
+        If generated mask extends beyond bitmap bounds, replicate bitmap edge colors,
+        just as SkShader made from SkShader::MakeBitmapShader with
+        SkShader::kClamp_TileMode set replicates the bitmap edge color when it samples
+        outside of its bounds.
+
+        @param image    SkImage containing pixels, dimensions, and format
+        @param lattice  division of bitmap into fixed and variable rectangles
+        @param dst      destination SkRect of image to draw to
+        @param filter   what technique to use when sampling the image
+        @param paint    SkPaint containing SkBlendMode, SkColorFilter, SkImageFilter,
+                        and so on; or nullptr
+    */
+    void drawImageLattice(const SkImage* image, const Lattice& lattice, const SkRect& dst,
+                          SkFilterMode filter, const SkPaint* paint = nullptr);
+    void drawImageLattice(const SkImage* image, const Lattice& lattice, const SkRect& dst) {
+        this->drawImageLattice(image, lattice, dst, SkFilterMode::kNearest, nullptr);
+    }
+
+    /**
+     * Experimental. Controls anti-aliasing of each edge of images in an image-set.
+     */
+    enum QuadAAFlags : unsigned {
+        kLeft_QuadAAFlag    = 0b0001,
+        kTop_QuadAAFlag     = 0b0010,
+        kRight_QuadAAFlag   = 0b0100,
+        kBottom_QuadAAFlag  = 0b1000,
+
+        kNone_QuadAAFlags   = 0b0000,
+        kAll_QuadAAFlags    = 0b1111,
+    };
+
+    /** This is used by the experimental API below. */
+    struct SK_API ImageSetEntry {
+        ImageSetEntry(sk_sp<const SkImage> image, const SkRect& srcRect, const SkRect& dstRect,
+                      int matrixIndex, float alpha, unsigned aaFlags, bool hasClip);
+
+        ImageSetEntry(sk_sp<const SkImage> image, const SkRect& srcRect, const SkRect& dstRect,
+                      float alpha, unsigned aaFlags);
+
+        ImageSetEntry();
+        ~ImageSetEntry();
+        ImageSetEntry(const ImageSetEntry&);
+        ImageSetEntry& operator=(const ImageSetEntry&);
+
+        sk_sp<const SkImage> fImage;
+        SkRect fSrcRect;
+        SkRect fDstRect;
+        int fMatrixIndex = -1; // Index into the preViewMatrices arg, or < 0
+        float fAlpha = 1.f;
+        unsigned fAAFlags = kNone_QuadAAFlags; // QuadAAFlags
+        bool fHasClip = false; // True to use next 4 points in dstClip arg as quad
+    };
+
+    /**
+     * This is an experimental API for the SkiaRenderer Chromium project, and its API will surely
+     * evolve if it is not removed outright.
+     *
+     * This behaves very similarly to drawRect() combined with a clipPath() formed by clip
+     * quadrilateral. 'rect' and 'clip' are in the same coordinate space. If 'clip' is null, then it
+     * is as if the rectangle was not clipped (or, alternatively, clipped to itself). If not null,
+     * then it must provide 4 points.
+     *
+     * In addition to combining the draw and clipping into one operation, this function adds the
+     * additional capability of controlling each of the rectangle's edges anti-aliasing
+     * independently.  The edges of the clip will respect the per-edge AA flags. It is required that
+     * 'clip' be contained inside 'rect'. In terms of mapping to edge labels, the 'clip' points
+     * should be ordered top-left, top-right, bottom-right, bottom-left so that the edge between [0]
+     * and [1] is "top", [1] and [2] is "right", [2] and [3] is "bottom", and [3] and [0] is "left".
+     * This ordering matches SkRect::toQuad().
+     *
+     * This API only draws solid color, filled rectangles so it does not accept a full SkPaint.
+     */
+    void experimental_DrawEdgeAAQuad(const SkRect& rect, const SkPoint clip[4], QuadAAFlags aaFlags,
+                                     const SkColor4f& color, SkBlendMode mode);
+    void experimental_DrawEdgeAAQuad(const SkRect& rect, const SkPoint clip[4], QuadAAFlags aaFlags,
+                                     SkColor color, SkBlendMode mode) {
+        this->experimental_DrawEdgeAAQuad(rect, clip, aaFlags, SkColor4f::FromColor(color), mode);
+    }
+
+    /**
+     * This is an bulk variant of experimental_DrawEdgeAAQuad() that renders 'cnt' textured quads.
+     * For each entry, 'fDstRect' is rendered with its clip (determined by entry's 'fHasClip' and
+     * the current index in 'dstClip'). The entry's fImage is applied to the destination rectangle
+     * by sampling from 'fSrcRect' sub-image.  The corners of 'fSrcRect' map to the corners of
+     * 'fDstRect', just like in drawImageRect(), and they will be properly interpolated when
+     * applying a clip.
+     *
+     * Like experimental_DrawEdgeAAQuad(), each entry can specify edge AA flags that apply to both
+     * the destination rect and its clip.
+     *
+     * If provided, the 'dstClips' array must have length equal 4 * the number of entries with
+     * fHasClip true. If 'dstClips' is null, every entry must have 'fHasClip' set to false. The
+     * destination clip coordinates will be read consecutively with the image set entries, advancing
+     * by 4 points every time an entry with fHasClip is passed.
+     *
+     * This entry point supports per-entry manipulations to the canvas's current matrix. If an
+     * entry provides 'fMatrixIndex' >= 0, it will be drawn as if the canvas's CTM was
+     * canvas->getTotalMatrix() * preViewMatrices[fMatrixIndex]. If 'fMatrixIndex' is less than 0,
+     * the pre-view matrix transform is implicitly the identity, so it will be drawn using just the
+     * current canvas matrix. The pre-view matrix modifies the canvas's view matrix, it does not
+     * affect the local coordinates of each entry.
+     *
+     * An optional paint may be provided, which supports the same subset of features usable with
+     * drawImageRect (i.e. assumed to be filled and no path effects). When a paint is provided, the
+     * image set is drawn as if each image used the applied paint independently, so each is affected
+     * by the image, color, and/or mask filter.
+     */
+    void experimental_DrawEdgeAAImageSet(const ImageSetEntry imageSet[], int cnt,
+                                         const SkPoint dstClips[], const SkMatrix preViewMatrices[],
+                                         const SkSamplingOptions&, const SkPaint* paint = nullptr,
+                                         SrcRectConstraint constraint = kStrict_SrcRectConstraint);
+
+    /** Draws text, with origin at (x, y), using clip, SkMatrix, SkFont font,
+        and SkPaint paint.
+
+        When encoding is SkTextEncoding::kUTF8, SkTextEncoding::kUTF16, or
+        SkTextEncoding::kUTF32, this function uses the default
+        character-to-glyph mapping from the SkTypeface in font.  It does not
+        perform typeface fallback for characters not found in the SkTypeface.
+        It does not perform kerning or other complex shaping; glyphs are
+        positioned based on their default advances.
+
+        Text meaning depends on SkTextEncoding.
+
+        Text size is affected by SkMatrix and SkFont text size. Default text
+        size is 12 point.
+
+        All elements of paint: SkPathEffect, SkMaskFilter, SkShader,
+        SkColorFilter, and SkImageFilter; apply to text. By
+        default, draws filled black glyphs.
+
+        @param text        character code points or glyphs drawn
+        @param byteLength  byte length of text array
+        @param encoding    text encoding used in the text array
+        @param x           start of text on x-axis
+        @param y           start of text on y-axis
+        @param font        typeface, text size and so, used to describe the text
+        @param paint       blend, color, and so on, used to draw
+    */
+    void drawSimpleText(const void* text, size_t byteLength, SkTextEncoding encoding,
+                        SkScalar x, SkScalar y, const SkFont& font, const SkPaint& paint);
+
+    /** Draws null terminated string, with origin at (x, y), using clip, SkMatrix,
+        SkFont font, and SkPaint paint.
+
+        This function uses the default character-to-glyph mapping from the
+        SkTypeface in font.  It does not perform typeface fallback for
+        characters not found in the SkTypeface.  It does not perform kerning;
+        glyphs are positioned based on their default advances.
+
+        String str is encoded as UTF-8.
+
+        Text size is affected by SkMatrix and font text size. Default text
+        size is 12 point.
+
+        All elements of paint: SkPathEffect, SkMaskFilter, SkShader,
+        SkColorFilter, and SkImageFilter; apply to text. By
+        default, draws filled black glyphs.
+
+        @param str     character code points drawn,
+                       ending with a char value of zero
+        @param x       start of string on x-axis
+        @param y       start of string on y-axis
+        @param font    typeface, text size and so, used to describe the text
+        @param paint   blend, color, and so on, used to draw
+    */
+    void drawString(const char str[], SkScalar x, SkScalar y, const SkFont& font,
+                    const SkPaint& paint) {
+        this->drawSimpleText(str, strlen(str), SkTextEncoding::kUTF8, x, y, font, paint);
+    }
+
+    /** Draws SkString, with origin at (x, y), using clip, SkMatrix, SkFont font,
+        and SkPaint paint.
+
+        This function uses the default character-to-glyph mapping from the
+        SkTypeface in font.  It does not perform typeface fallback for
+        characters not found in the SkTypeface.  It does not perform kerning;
+        glyphs are positioned based on their default advances.
+
+        SkString str is encoded as UTF-8.
+
+        Text size is affected by SkMatrix and SkFont text size. Default text
+        size is 12 point.
+
+        All elements of paint: SkPathEffect, SkMaskFilter, SkShader,
+        SkColorFilter, and SkImageFilter; apply to text. By
+        default, draws filled black glyphs.
+
+        @param str     character code points drawn,
+                       ending with a char value of zero
+        @param x       start of string on x-axis
+        @param y       start of string on y-axis
+        @param font    typeface, text size and so, used to describe the text
+        @param paint   blend, color, and so on, used to draw
+    */
+    void drawString(const SkString& str, SkScalar x, SkScalar y, const SkFont& font,
+                    const SkPaint& paint) {
+        this->drawSimpleText(str.c_str(), str.size(), SkTextEncoding::kUTF8, x, y, font, paint);
+    }
+
+    /** Draws count glyphs, at positions relative to origin styled with font and paint with
+        supporting utf8 and cluster information.
+
+       This function draw glyphs at the given positions relative to the given origin.
+       It does not perform typeface fallback for glyphs not found in the SkTypeface in font.
+
+       The drawing obeys the current transform matrix and clipping.
+
+       All elements of paint: SkPathEffect, SkMaskFilter, SkShader,
+       SkColorFilter, and SkImageFilter; apply to text. By
+       default, draws filled black glyphs.
+
+       @param count           number of glyphs to draw
+       @param glyphs          the array of glyphIDs to draw
+       @param positions       where to draw each glyph relative to origin
+       @param clusters        array of size count of cluster information
+       @param textByteCount   size of the utf8text
+       @param utf8text        utf8text supporting information for the glyphs
+       @param origin          the origin of all the positions
+       @param font            typeface, text size and so, used to describe the text
+       @param paint           blend, color, and so on, used to draw
+    */
+    void drawGlyphs(int count, const SkGlyphID glyphs[], const SkPoint positions[],
+                    const uint32_t clusters[], int textByteCount, const char utf8text[],
+                    SkPoint origin, const SkFont& font, const SkPaint& paint);
+
+    /** Draws count glyphs, at positions relative to origin styled with font and paint.
+
+        This function draw glyphs at the given positions relative to the given origin.
+        It does not perform typeface fallback for glyphs not found in the SkTypeface in font.
+
+        The drawing obeys the current transform matrix and clipping.
+
+        All elements of paint: SkPathEffect, SkMaskFilter, SkShader,
+        SkColorFilter, and SkImageFilter; apply to text. By
+        default, draws filled black glyphs.
+
+        @param count       number of glyphs to draw
+        @param glyphs      the array of glyphIDs to draw
+        @param positions   where to draw each glyph relative to origin
+        @param origin      the origin of all the positions
+        @param font        typeface, text size and so, used to describe the text
+        @param paint       blend, color, and so on, used to draw
+    */
+    void drawGlyphs(int count, const SkGlyphID glyphs[], const SkPoint positions[],
+                    SkPoint origin, const SkFont& font, const SkPaint& paint);
+
+    /** Draws count glyphs, at positions relative to origin styled with font and paint.
+
+        This function draw glyphs using the given scaling and rotations. They are positioned
+        relative to the given origin. It does not perform typeface fallback for glyphs not found
+        in the SkTypeface in font.
+
+        The drawing obeys the current transform matrix and clipping.
+
+        All elements of paint: SkPathEffect, SkMaskFilter, SkShader,
+        SkColorFilter, and SkImageFilter; apply to text. By
+        default, draws filled black glyphs.
+
+        @param count    number of glyphs to draw
+        @param glyphs   the array of glyphIDs to draw
+        @param xforms   where to draw and orient each glyph
+        @param origin   the origin of all the positions
+        @param font     typeface, text size and so, used to describe the text
+        @param paint    blend, color, and so on, used to draw
+    */
+    void drawGlyphs(int count, const SkGlyphID glyphs[], const SkRSXform xforms[],
+                    SkPoint origin, const SkFont& font, const SkPaint& paint);
+
+    /** Draws SkTextBlob blob at (x, y), using clip, SkMatrix, and SkPaint paint.
+
+        blob contains glyphs, their positions, and paint attributes specific to text:
+        SkTypeface, SkPaint text size, SkPaint text scale x,
+        SkPaint text skew x, SkPaint::Align, SkPaint::Hinting, anti-alias, SkPaint fake bold,
+        SkPaint font embedded bitmaps, SkPaint full hinting spacing, LCD text, SkPaint linear text,
+        and SkPaint subpixel text.
+
+        SkTextEncoding must be set to SkTextEncoding::kGlyphID.
+
+        Elements of paint: anti-alias, SkBlendMode, color including alpha,
+        SkColorFilter, SkPaint dither, SkMaskFilter, SkPathEffect, SkShader, and
+        SkPaint::Style; apply to blob. If SkPaint contains SkPaint::kStroke_Style:
+        SkPaint miter limit, SkPaint::Cap, SkPaint::Join, and SkPaint stroke width;
+        apply to SkPath created from blob.
+
+        @param blob   glyphs, positions, and their paints' text size, typeface, and so on
+        @param x      horizontal offset applied to blob
+        @param y      vertical offset applied to blob
+        @param paint  blend, color, stroking, and so on, used to draw
+
+        example: https://fiddle.skia.org/c/@Canvas_drawTextBlob
+    */
+    void drawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y, const SkPaint& paint);
+
+    /** Draws SkTextBlob blob at (x, y), using clip, SkMatrix, and SkPaint paint.
+
+        blob contains glyphs, their positions, and paint attributes specific to text:
+        SkTypeface, SkPaint text size, SkPaint text scale x,
+        SkPaint text skew x, SkPaint::Align, SkPaint::Hinting, anti-alias, SkPaint fake bold,
+        SkPaint font embedded bitmaps, SkPaint full hinting spacing, LCD text, SkPaint linear text,
+        and SkPaint subpixel text.
+
+        SkTextEncoding must be set to SkTextEncoding::kGlyphID.
+
+        Elements of paint: SkPathEffect, SkMaskFilter, SkShader, SkColorFilter,
+        and SkImageFilter; apply to blob.
+
+        @param blob   glyphs, positions, and their paints' text size, typeface, and so on
+        @param x      horizontal offset applied to blob
+        @param y      vertical offset applied to blob
+        @param paint  blend, color, stroking, and so on, used to draw
+    */
+    void drawTextBlob(const sk_sp<SkTextBlob>& blob, SkScalar x, SkScalar y, const SkPaint& paint) {
+        this->drawTextBlob(blob.get(), x, y, paint);
+    }
+
+    /** Draws SkPicture picture, using clip and SkMatrix.
+        Clip and SkMatrix are unchanged by picture contents, as if
+        save() was called before and restore() was called after drawPicture().
+
+        SkPicture records a series of draw commands for later playback.
+
+        @param picture  recorded drawing commands to play
+    */
+    void drawPicture(const SkPicture* picture) {
+        this->drawPicture(picture, nullptr, nullptr);
+    }
+
+    /** Draws SkPicture picture, using clip and SkMatrix.
+        Clip and SkMatrix are unchanged by picture contents, as if
+        save() was called before and restore() was called after drawPicture().
+
+        SkPicture records a series of draw commands for later playback.
+
+        @param picture  recorded drawing commands to play
+    */
+    void drawPicture(const sk_sp<SkPicture>& picture) {
+        this->drawPicture(picture.get());
+    }
+
+    /** Draws SkPicture picture, using clip and SkMatrix; transforming picture with
+        SkMatrix matrix, if provided; and use SkPaint paint alpha, SkColorFilter,
+        SkImageFilter, and SkBlendMode, if provided.
+
+        If paint is non-null, then the picture is always drawn into a temporary layer before
+        actually landing on the canvas. Note that drawing into a layer can also change its
+        appearance if there are any non-associative blendModes inside any of the pictures elements.
+
+        @param picture  recorded drawing commands to play
+        @param matrix   SkMatrix to rotate, scale, translate, and so on; may be nullptr
+        @param paint    SkPaint to apply transparency, filtering, and so on; may be nullptr
+
+        example: https://fiddle.skia.org/c/@Canvas_drawPicture_3
+    */
+    void drawPicture(const SkPicture* picture, const SkMatrix* matrix, const SkPaint* paint);
+
+    /** Draws SkPicture picture, using clip and SkMatrix; transforming picture with
+        SkMatrix matrix, if provided; and use SkPaint paint alpha, SkColorFilter,
+        SkImageFilter, and SkBlendMode, if provided.
+
+        If paint is non-null, then the picture is always drawn into a temporary layer before
+        actually landing on the canvas. Note that drawing into a layer can also change its
+        appearance if there are any non-associative blendModes inside any of the pictures elements.
+
+        @param picture  recorded drawing commands to play
+        @param matrix   SkMatrix to rotate, scale, translate, and so on; may be nullptr
+        @param paint    SkPaint to apply transparency, filtering, and so on; may be nullptr
+    */
+    void drawPicture(const sk_sp<SkPicture>& picture, const SkMatrix* matrix,
+                     const SkPaint* paint) {
+        this->drawPicture(picture.get(), matrix, paint);
+    }
+
+    /** Draws SkVertices vertices, a triangle mesh, using clip and SkMatrix.
+        If paint contains an SkShader and vertices does not contain texCoords, the shader
+        is mapped using the vertices' positions.
+
+        SkBlendMode is ignored if SkVertices does not have colors. Otherwise, it combines
+           - the SkShader if SkPaint contains SkShader
+           - or the opaque SkPaint color if SkPaint does not contain SkShader
+        as the src of the blend and the interpolated vertex colors as the dst.
+
+        SkMaskFilter, SkPathEffect, and antialiasing on SkPaint are ignored.
+
+        @param vertices  triangle mesh to draw
+        @param mode      combines vertices' colors with SkShader if present or SkPaint opaque color
+                         if not. Ignored if the vertices do not contain color.
+        @param paint     specifies the SkShader, used as SkVertices texture, and SkColorFilter.
+
+        example: https://fiddle.skia.org/c/@Canvas_drawVertices
+    */
+    void drawVertices(const SkVertices* vertices, SkBlendMode mode, const SkPaint& paint);
+
+    /** Draws SkVertices vertices, a triangle mesh, using clip and SkMatrix.
+        If paint contains an SkShader and vertices does not contain texCoords, the shader
+        is mapped using the vertices' positions.
+
+        SkBlendMode is ignored if SkVertices does not have colors. Otherwise, it combines
+           - the SkShader if SkPaint contains SkShader
+           - or the opaque SkPaint color if SkPaint does not contain SkShader
+        as the src of the blend and the interpolated vertex colors as the dst.
+
+        SkMaskFilter, SkPathEffect, and antialiasing on SkPaint are ignored.
+
+        @param vertices  triangle mesh to draw
+        @param mode      combines vertices' colors with SkShader if present or SkPaint opaque color
+                         if not. Ignored if the vertices do not contain color.
+        @param paint     specifies the SkShader, used as SkVertices texture, may be nullptr
+
+        example: https://fiddle.skia.org/c/@Canvas_drawVertices_2
+    */
+    void drawVertices(const sk_sp<SkVertices>& vertices, SkBlendMode mode, const SkPaint& paint);
+
+#if defined(SK_ENABLE_EXPERIMENTAL_CUSTOM_MESH) && defined(SK_ENABLE_SKSL)
+    /**
+        Experimental, under active development, and subject to change without notice.
+
+        Draws a mesh using a user-defined specification (see SkCustomMeshSpecification).
+
+        SkBlender is ignored if SkCustomMesh's specification does not output fragment shader color.
+        Otherwise, it combines
+            - the SkShader if SkPaint contains SkShader
+            - or the opaque SkPaint color if SkPaint does not contain SkShader
+        as the src of the blend and the mesh's fragment color as the dst.
+
+        SkMaskFilter, SkPathEffect, and antialiasing on SkPaint are ignored.
+
+        @param cm        the custom mesh vertices and compatible specification.
+        @param blender   combines vertices colors with SkShader if present or SkPaint opaque color
+                         if not. Ignored if the custom mesh does not output color. Defaults to
+                         SkBlendMode::kModulate if nullptr.
+        @param paint     specifies the SkShader, used as SkVertices texture, may be nullptr
+    */
+    void drawCustomMesh(SkCustomMesh cm, sk_sp<SkBlender> blender, const SkPaint& paint);
+#endif
+
+    /** Draws a Coons patch: the interpolation of four cubics with shared corners,
+        associating a color, and optionally a texture SkPoint, with each corner.
+
+        SkPoint array cubics specifies four SkPath cubic starting at the top-left corner,
+        in clockwise order, sharing every fourth point. The last SkPath cubic ends at the
+        first point.
+
+        Color array color associates colors with corners in top-left, top-right,
+        bottom-right, bottom-left order.
+
+        If paint contains SkShader, SkPoint array texCoords maps SkShader as texture to
+        corners in top-left, top-right, bottom-right, bottom-left order. If texCoords is
+        nullptr, SkShader is mapped using positions (derived from cubics).
+
+        SkBlendMode is ignored if colors is null. Otherwise, it combines
+            - the SkShader if SkPaint contains SkShader
+            - or the opaque SkPaint color if SkPaint does not contain SkShader
+        as the src of the blend and the interpolated patch colors as the dst.
+
+        SkMaskFilter, SkPathEffect, and antialiasing on SkPaint are ignored.
+
+        @param cubics     SkPath cubic array, sharing common points
+        @param colors     color array, one for each corner
+        @param texCoords  SkPoint array of texture coordinates, mapping SkShader to corners;
+                          may be nullptr
+        @param mode       combines patch's colors with SkShader if present or SkPaint opaque color
+                          if not. Ignored if colors is null.
+        @param paint      SkShader, SkColorFilter, SkBlendMode, used to draw
+    */
+    void drawPatch(const SkPoint cubics[12], const SkColor colors[4],
+                   const SkPoint texCoords[4], SkBlendMode mode, const SkPaint& paint);
+
+    /** Draws a set of sprites from atlas, using clip, SkMatrix, and optional SkPaint paint.
+        paint uses anti-alias, alpha, SkColorFilter, SkImageFilter, and SkBlendMode
+        to draw, if present. For each entry in the array, SkRect tex locates sprite in
+        atlas, and SkRSXform xform transforms it into destination space.
+
+        SkMaskFilter and SkPathEffect on paint are ignored.
+
+        xform, tex, and colors if present, must contain count entries.
+        Optional colors are applied for each sprite using SkBlendMode mode, treating
+        sprite as source and colors as destination.
+        Optional cullRect is a conservative bounds of all transformed sprites.
+        If cullRect is outside of clip, canvas can skip drawing.
+
+        If atlas is nullptr, this draws nothing.
+
+        @param atlas     SkImage containing sprites
+        @param xform     SkRSXform mappings for sprites in atlas
+        @param tex       SkRect locations of sprites in atlas
+        @param colors    one per sprite, blended with sprite using SkBlendMode; may be nullptr
+        @param count     number of sprites to draw
+        @param mode      SkBlendMode combining colors and sprites
+        @param sampling  SkSamplingOptions used when sampling from the atlas image
+        @param cullRect  bounds of transformed sprites for efficient clipping; may be nullptr
+        @param paint     SkColorFilter, SkImageFilter, SkBlendMode, and so on; may be nullptr
+    */
+    void drawAtlas(const SkImage* atlas, const SkRSXform xform[], const SkRect tex[],
+                   const SkColor colors[], int count, SkBlendMode mode,
+                   const SkSamplingOptions& sampling, const SkRect* cullRect, const SkPaint* paint);
+
+    /** Draws SkDrawable drawable using clip and SkMatrix, concatenated with
+        optional matrix.
+
+        If SkCanvas has an asynchronous implementation, as is the case
+        when it is recording into SkPicture, then drawable will be referenced,
+        so that SkDrawable::draw() can be called when the operation is finalized. To force
+        immediate drawing, call SkDrawable::draw() instead.
+
+        @param drawable  custom struct encapsulating drawing commands
+        @param matrix    transformation applied to drawing; may be nullptr
+
+        example: https://fiddle.skia.org/c/@Canvas_drawDrawable
+    */
+    void drawDrawable(SkDrawable* drawable, const SkMatrix* matrix = nullptr);
+
+    /** Draws SkDrawable drawable using clip and SkMatrix, offset by (x, y).
+
+        If SkCanvas has an asynchronous implementation, as is the case
+        when it is recording into SkPicture, then drawable will be referenced,
+        so that SkDrawable::draw() can be called when the operation is finalized. To force
+        immediate drawing, call SkDrawable::draw() instead.
+
+        @param drawable  custom struct encapsulating drawing commands
+        @param x         offset into SkCanvas writable pixels on x-axis
+        @param y         offset into SkCanvas writable pixels on y-axis
+
+        example: https://fiddle.skia.org/c/@Canvas_drawDrawable_2
+    */
+    void drawDrawable(SkDrawable* drawable, SkScalar x, SkScalar y);
+
+    /** Associates SkRect on SkCanvas with an annotation; a key-value pair, where the key is
+        a null-terminated UTF-8 string, and optional value is stored as SkData.
+
+        Only some canvas implementations, such as recording to SkPicture, or drawing to
+        document PDF, use annotations.
+
+        @param rect   SkRect extent of canvas to annotate
+        @param key    string used for lookup
+        @param value  data holding value stored in annotation
+
+        example: https://fiddle.skia.org/c/@Canvas_drawAnnotation_2
+    */
+    void drawAnnotation(const SkRect& rect, const char key[], SkData* value);
+
+    /** Associates SkRect on SkCanvas when an annotation; a key-value pair, where the key is
+        a null-terminated UTF-8 string, and optional value is stored as SkData.
+
+        Only some canvas implementations, such as recording to SkPicture, or drawing to
+        document PDF, use annotations.
+
+        @param rect   SkRect extent of canvas to annotate
+        @param key    string used for lookup
+        @param value  data holding value stored in annotation
+    */
+    void drawAnnotation(const SkRect& rect, const char key[], const sk_sp<SkData>& value) {
+        this->drawAnnotation(rect, key, value.get());
+    }
+
+    /** Returns true if clip is empty; that is, nothing will draw.
+
+        May do work when called; it should not be called
+        more often than needed. However, once called, subsequent calls perform no
+        work until clip changes.
+
+        @return  true if clip is empty
+
+        example: https://fiddle.skia.org/c/@Canvas_isClipEmpty
+    */
+    virtual bool isClipEmpty() const;
+
+    /** Returns true if clip is SkRect and not empty.
+        Returns false if the clip is empty, or if it is not SkRect.
+
+        @return  true if clip is SkRect and not empty
+
+        example: https://fiddle.skia.org/c/@Canvas_isClipRect
+    */
+    virtual bool isClipRect() const;
+
+    /** Returns the current transform from local coordinates to the 'device', which for most
+     *  purposes means pixels.
+     *
+     *  @return transformation from local coordinates to device / pixels.
+     */
+    SkM44 getLocalToDevice() const;
+
+    /**
+     *  Throws away the 3rd row and column in the matrix, so be warned.
+     */
+    SkMatrix getLocalToDeviceAs3x3() const {
+        return this->getLocalToDevice().asM33();
+    }
+
+#ifdef SK_SUPPORT_LEGACY_GETTOTALMATRIX
+    /** DEPRECATED
+     *  Legacy version of getLocalToDevice(), which strips away any Z information, and
+     *  just returns a 3x3 version.
+     *
+     *  @return 3x3 version of getLocalToDevice()
+     *
+     *  example: https://fiddle.skia.org/c/@Canvas_getTotalMatrix
+     *  example: https://fiddle.skia.org/c/@Clip
+     */
+    SkMatrix getTotalMatrix() const;
+#endif
+
+    ///////////////////////////////////////////////////////////////////////////
+
+#if defined(SK_BUILD_FOR_ANDROID_FRAMEWORK) && SK_SUPPORT_GPU
+    // These methods exist to support WebView in Android Framework.
+    SkIRect topLayerBounds() const;
+    GrBackendRenderTarget topLayerBackendRenderTarget() const;
+#endif
+
+    /**
+     *  Returns the global clip as a region. If the clip contains AA, then only the bounds
+     *  of the clip may be returned.
+     */
+    void temporary_internal_getRgnClip(SkRegion* region);
+
+    void private_draw_shadow_rec(const SkPath&, const SkDrawShadowRec&);
+
+
+protected:
+    // default impl defers to getDevice()->newSurface(info)
+    virtual sk_sp<SkSurface> onNewSurface(const SkImageInfo& info, const SkSurfaceProps& props);
+
+    // default impl defers to its device
+    virtual bool onPeekPixels(SkPixmap* pixmap);
+    virtual bool onAccessTopLayerPixels(SkPixmap* pixmap);
+    virtual SkImageInfo onImageInfo() const;
+    virtual bool onGetProps(SkSurfaceProps* props) const;
+    virtual void onFlush();
+
+    // Subclass save/restore notifiers.
+    // Overriders should call the corresponding INHERITED method up the inheritance chain.
+    // getSaveLayerStrategy()'s return value may suppress full layer allocation.
+    enum SaveLayerStrategy {
+        kFullLayer_SaveLayerStrategy,
+        kNoLayer_SaveLayerStrategy,
+    };
+
+    virtual void willSave() {}
+    // Overriders should call the corresponding INHERITED method up the inheritance chain.
+    virtual SaveLayerStrategy getSaveLayerStrategy(const SaveLayerRec& ) {
+        return kFullLayer_SaveLayerStrategy;
+    }
+
+    // returns true if we should actually perform the saveBehind, or false if we should just save.
+    virtual bool onDoSaveBehind(const SkRect*) { return true; }
+    virtual void willRestore() {}
+    virtual void didRestore() {}
+
+    virtual void didConcat44(const SkM44&) {}
+    virtual void didSetM44(const SkM44&) {}
+    virtual void didTranslate(SkScalar, SkScalar) {}
+    virtual void didScale(SkScalar, SkScalar) {}
+
+#ifndef SK_ENABLE_EXPERIMENTAL_CUSTOM_MESH
+    // Define this in protected so we can still access internally for testing.
+    void drawCustomMesh(SkCustomMesh cm, sk_sp<SkBlender> blender, const SkPaint& paint);
+#endif
+
+    // NOTE: If you are adding a new onDraw virtual to SkCanvas, PLEASE add an override to
+    // SkCanvasVirtualEnforcer (in SkCanvasVirtualEnforcer.h). This ensures that subclasses using
+    // that mechanism  will be required to implement the new function.
+    virtual void onDrawPaint(const SkPaint& paint);
+    virtual void onDrawBehind(const SkPaint& paint);
+    virtual void onDrawRect(const SkRect& rect, const SkPaint& paint);
+    virtual void onDrawRRect(const SkRRect& rrect, const SkPaint& paint);
+    virtual void onDrawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint& paint);
+    virtual void onDrawOval(const SkRect& rect, const SkPaint& paint);
+    virtual void onDrawArc(const SkRect& rect, SkScalar startAngle, SkScalar sweepAngle,
+                           bool useCenter, const SkPaint& paint);
+    virtual void onDrawPath(const SkPath& path, const SkPaint& paint);
+    virtual void onDrawRegion(const SkRegion& region, const SkPaint& paint);
+
+    virtual void onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
+                                const SkPaint& paint);
+
+    virtual void onDrawGlyphRunList(const SkGlyphRunList& glyphRunList, const SkPaint& paint);
+
+    virtual void onDrawPatch(const SkPoint cubics[12], const SkColor colors[4],
+                           const SkPoint texCoords[4], SkBlendMode mode, const SkPaint& paint);
+    virtual void onDrawPoints(PointMode mode, size_t count, const SkPoint pts[],
+                              const SkPaint& paint);
+
+    virtual void onDrawImage2(const SkImage*, SkScalar dx, SkScalar dy, const SkSamplingOptions&,
+                              const SkPaint*);
+    virtual void onDrawImageRect2(const SkImage*, const SkRect& src, const SkRect& dst,
+                                  const SkSamplingOptions&, const SkPaint*, SrcRectConstraint);
+    virtual void onDrawImageLattice2(const SkImage*, const Lattice&, const SkRect& dst,
+                                     SkFilterMode, const SkPaint*);
+    virtual void onDrawAtlas2(const SkImage*, const SkRSXform[], const SkRect src[],
+                              const SkColor[], int count, SkBlendMode, const SkSamplingOptions&,
+                              const SkRect* cull, const SkPaint*);
+    virtual void onDrawEdgeAAImageSet2(const ImageSetEntry imageSet[], int count,
+                                       const SkPoint dstClips[], const SkMatrix preViewMatrices[],
+                                       const SkSamplingOptions&, const SkPaint*,
+                                       SrcRectConstraint);
+
+    virtual void onDrawVerticesObject(const SkVertices* vertices, SkBlendMode mode,
+                                      const SkPaint& paint);
+#ifdef SK_ENABLE_SKSL
+    virtual void onDrawCustomMesh(SkCustomMesh, sk_sp<SkBlender>, const SkPaint&);
+#endif
+    virtual void onDrawAnnotation(const SkRect& rect, const char key[], SkData* value);
+    virtual void onDrawShadowRec(const SkPath&, const SkDrawShadowRec&);
+
+    virtual void onDrawDrawable(SkDrawable* drawable, const SkMatrix* matrix);
+    virtual void onDrawPicture(const SkPicture* picture, const SkMatrix* matrix,
+                               const SkPaint* paint);
+
+    virtual void onDrawEdgeAAQuad(const SkRect& rect, const SkPoint clip[4], QuadAAFlags aaFlags,
+                                  const SkColor4f& color, SkBlendMode mode);
+
+    enum ClipEdgeStyle {
+        kHard_ClipEdgeStyle,
+        kSoft_ClipEdgeStyle
+    };
+
+    virtual void onClipRect(const SkRect& rect, SkClipOp op, ClipEdgeStyle edgeStyle);
+    virtual void onClipRRect(const SkRRect& rrect, SkClipOp op, ClipEdgeStyle edgeStyle);
+    virtual void onClipPath(const SkPath& path, SkClipOp op, ClipEdgeStyle edgeStyle);
+    virtual void onClipShader(sk_sp<SkShader>, SkClipOp);
+    virtual void onClipRegion(const SkRegion& deviceRgn, SkClipOp op);
+    virtual void onResetClip();
+
+    virtual void onDiscard();
+
+#if SK_SUPPORT_GPU
+    /** Experimental
+     */
+    virtual sk_sp<GrSlug> doConvertBlobToSlug(
+            const SkTextBlob& blob, SkPoint origin, const SkPaint& paint);
+
+    /** Experimental
+     */
+    virtual void doDrawSlug(GrSlug* slug);
+#endif
+
+private:
+
+    enum ShaderOverrideOpacity {
+        kNone_ShaderOverrideOpacity,        //!< there is no overriding shader (bitmap or image)
+        kOpaque_ShaderOverrideOpacity,      //!< the overriding shader is opaque
+        kNotOpaque_ShaderOverrideOpacity,   //!< the overriding shader may not be opaque
+    };
+
+    // notify our surface (if we have one) that we are about to draw, so it
+    // can perform copy-on-write or invalidate any cached images
+    // returns false if the copy failed
+    bool SK_WARN_UNUSED_RESULT predrawNotify(bool willOverwritesEntireSurface = false);
+    bool SK_WARN_UNUSED_RESULT predrawNotify(const SkRect*, const SkPaint*, ShaderOverrideOpacity);
+
+    enum class CheckForOverwrite : bool {
+        kNo = false,
+        kYes = true
+    };
+    // call the appropriate predrawNotify and create a layer if needed.
+    skstd::optional<AutoLayerForImageFilter> aboutToDraw(
+        SkCanvas* canvas,
+        const SkPaint& paint,
+        const SkRect* rawBounds = nullptr,
+        CheckForOverwrite = CheckForOverwrite::kNo,
+        ShaderOverrideOpacity = kNone_ShaderOverrideOpacity);
+
+    // The bottom-most device in the stack, only changed by init(). Image properties and the final
+    // canvas pixels are determined by this device.
+    SkBaseDevice* baseDevice() const {
+        SkASSERT(fBaseDevice);
+        return fBaseDevice.get();
+    }
+
+    // The top-most device in the stack, will change within saveLayer()'s. All drawing and clipping
+    // operations should route to this device.
+    SkBaseDevice* topDevice() const;
+
+    // Canvases maintain a sparse stack of layers, where the top-most layer receives the drawing,
+    // clip, and matrix commands. There is a layer per call to saveLayer() using the
+    // kFullLayer_SaveLayerStrategy.
+    struct Layer {
+        sk_sp<SkBaseDevice>  fDevice;
+        sk_sp<SkImageFilter> fImageFilter; // applied to layer *before* being drawn by paint
+        SkPaint              fPaint;
+        bool                 fDiscard;
+
+        Layer(sk_sp<SkBaseDevice> device, sk_sp<SkImageFilter> imageFilter, const SkPaint& paint);
+    };
+
+    // Encapsulate state needed to restore from saveBehind()
+    struct BackImage {
+        sk_sp<SkSpecialImage> fImage;
+        SkIPoint              fLoc;
+    };
+
+    class MCRec {
+    public:
+        // If not null, this MCRec corresponds with the saveLayer() record that made the layer.
+        // The base "layer" is not stored here, since it is stored inline in SkCanvas and has no
+        // restoration behavior.
+        std::unique_ptr<Layer> fLayer;
+
+        // This points to the device of the top-most layer (which may be lower in the stack), or
+        // to the canvas's fBaseDevice. The MCRec does not own the device.
+        SkBaseDevice* fDevice;
+
+        std::unique_ptr<BackImage> fBackImage;
+        SkM44 fMatrix;
+        int fDeferredSaveCount = 0;
+
+        MCRec(SkBaseDevice* device);
+        MCRec(const MCRec* prev);
+        ~MCRec();
+
+        void newLayer(sk_sp<SkBaseDevice> layerDevice,
+                      sk_sp<SkImageFilter> filter,
+                      const SkPaint& restorePaint);
+
+        void reset(SkBaseDevice* device);
+    };
+
+    SkDeque     fMCStack;
+    // points to top of stack
+    MCRec*      fMCRec;
+
+    // the first N recs that can fit here mean we won't call malloc
+    static constexpr int kMCRecSize      = 96; // most recent measurement
+    static constexpr int kMCRecCount     = 32; // common depth for save/restores
+
+    intptr_t fMCRecStorage[kMCRecSize * kMCRecCount / sizeof(intptr_t)];
+
+    // Installed via init()
+    sk_sp<SkBaseDevice> fBaseDevice;
+    const SkSurfaceProps fProps;
+
+    int         fSaveCount;         // value returned by getSaveCount()
+
+    std::unique_ptr<SkRasterHandleAllocator> fAllocator;
+
+    SkSurface_Base*  fSurfaceBase;
+    SkSurface_Base* getSurfaceBase() const { return fSurfaceBase; }
+    void setSurfaceBase(SkSurface_Base* sb) {
+        fSurfaceBase = sb;
+    }
+    friend class SkSurface_Base;
+    friend class SkSurface_Gpu;
+
+    SkIRect fClipRestrictionRect = SkIRect::MakeEmpty();
+    int fClipRestrictionSaveCount = -1;
+
+    void doSave();
+    void checkForDeferredSave();
+    void internalSetMatrix(const SkM44&);
+
+    friend class SkAndroidFrameworkUtils;
+    friend class SkCanvasPriv;      // needs to expose android functions for testing outside android
+    friend class AutoLayerForImageFilter;
+    friend class SkSurface_Raster;  // needs getDevice()
+    friend class SkNoDrawCanvas;    // needs resetForNextPicture()
+    friend class SkNWayCanvas;
+    friend class SkPictureRecord;   // predrawNotify (why does it need it? <reed>)
+    friend class SkOverdrawCanvas;
+    friend class SkRasterHandleAllocator;
+protected:
+    // For use by SkNoDrawCanvas (via SkCanvasVirtualEnforcer, which can't be a friend)
+    SkCanvas(const SkIRect& bounds);
+private:
+    SkCanvas(const SkBitmap&, std::unique_ptr<SkRasterHandleAllocator>,
+             SkRasterHandleAllocator::Handle);
+
+    SkCanvas(SkCanvas&&) = delete;
+    SkCanvas(const SkCanvas&) = delete;
+    SkCanvas& operator=(SkCanvas&&) = delete;
+    SkCanvas& operator=(const SkCanvas&) = delete;
+
+#if SK_SUPPORT_GPU
+    friend class GrSlug;
+    /** Experimental
+     * Convert a SkTextBlob to a GrSlug using the current canvas state.
+     */
+    sk_sp<GrSlug> convertBlobToSlug(const SkTextBlob& blob, SkPoint origin, const SkPaint& paint);
+
+    /** Experimental
+     * Draw an GrSlug given the current canvas state.
+     */
+    void drawSlug(GrSlug* slug);
+#endif
+
+    /** Experimental
+     *  Saves the specified subset of the current pixels in the current layer,
+     *  and then clears those pixels to transparent black.
+     *  Restores the pixels on restore() by drawing them in SkBlendMode::kDstOver.
+     *
+     *  @param subset   conservative bounds of the area to be saved / restored.
+     *  @return depth of save state stack before this call was made.
+     */
+    int only_axis_aligned_saveBehind(const SkRect* subset);
+
+    /**
+     *  Like drawPaint, but magically clipped to the most recent saveBehind buffer rectangle.
+     *  If there is no active saveBehind, then this draws nothing.
+     */
+    void drawClippedToSaveBehind(const SkPaint&);
+
+    void resetForNextPicture(const SkIRect& bounds);
+
+    // needs gettotalclip()
+    friend class SkCanvasStateUtils;
+
+    void init(sk_sp<SkBaseDevice>);
+
+    // All base onDrawX() functions should call this and skip drawing if it returns true.
+    // If 'matrix' is non-null, it maps the paint's fast bounds before checking for quick rejection
+    bool internalQuickReject(const SkRect& bounds, const SkPaint& paint,
+                             const SkMatrix* matrix = nullptr);
+
+    void internalDrawPaint(const SkPaint& paint);
+    void internalSaveLayer(const SaveLayerRec&, SaveLayerStrategy);
+    void internalSaveBehind(const SkRect*);
+
+    void internalConcat44(const SkM44&);
+
+    // shared by save() and saveLayer()
+    void internalSave();
+    void internalRestore();
+
+    enum class DeviceCompatibleWithFilter : bool {
+        // Check the src device's local-to-device matrix for compatibility with the filter, and if
+        // it is not compatible, introduce an intermediate image and transformation that allows the
+        // filter to be evaluated on the modified src content.
+        kUnknown = false,
+        // Assume that the src device's local-to-device matrix is compatible with the filter.
+        kYes     = true
+    };
+    /**
+     * Filters the contents of 'src' and draws the result into 'dst'. The filter is evaluated
+     * relative to the current canvas matrix, and src is drawn to dst using their relative transform
+     * 'paint' is applied after the filter and must not have a mask or image filter of its own.
+     * A null 'filter' behaves as if the identity filter were used.
+     *
+     * 'scaleFactor' is an extra uniform scale transform applied to downscale the 'src' image
+     * before any filtering, or as part of the copy, and is then drawn with 1/scaleFactor to 'dst'.
+     * Must be 1.0 if 'compat' is kYes (i.e. any scale factor has already been baked into the
+     * relative transforms between the devices).
+     */
+    void internalDrawDeviceWithFilter(SkBaseDevice* src, SkBaseDevice* dst,
+                                      const SkImageFilter* filter, const SkPaint& paint,
+                                      DeviceCompatibleWithFilter compat,
+                                      SkScalar scaleFactor = 1.f);
+
+    /*
+     *  Returns true if drawing the specified rect (or all if it is null) with the specified
+     *  paint (or default if null) would overwrite the entire root device of the canvas
+     *  (i.e. the canvas' surface if it had one).
+     */
+    bool wouldOverwriteEntireSurface(const SkRect*, const SkPaint*, ShaderOverrideOpacity) const;
+
+    /**
+     *  Returns true if the paint's imagefilter can be invoked directly, without needed a layer.
+     */
+    bool canDrawBitmapAsSprite(SkScalar x, SkScalar y, int w, int h, const SkSamplingOptions&,
+                               const SkPaint&);
+
+    /**
+     *  Returns true if the clip (for any active layer) contains antialiasing.
+     *  If the clip is empty, this will return false.
+     */
+    bool androidFramework_isClipAA() const;
+
+    /**
+     * Reset the clip to be wide-open (modulo any separately specified device clip restriction).
+     * This operate within the save/restore clip stack so it can be undone by restoring to an
+     * earlier save point.
+     */
+    void internal_private_resetClip();
+
+    virtual SkPaintFilterCanvas* internal_private_asPaintFilterCanvas() const { return nullptr; }
+
+    // Keep track of the device clip bounds in the canvas' global space to reject draws before
+    // invoking the top-level device.
+    SkRect fQuickRejectBounds;
+
+    // Compute the clip's bounds based on all clipped SkDevice's reported device bounds transformed
+    // into the canvas' global space.
+    SkRect computeDeviceClipBounds(bool outsetForAA=true) const;
+
+    class AutoUpdateQRBounds;
+    void validateClip() const;
+
+    std::unique_ptr<SkGlyphRunBuilder> fScratchGlyphRunBuilder;
+
+    using INHERITED = SkRefCnt;
+};
+
+/** \class SkAutoCanvasRestore
+    Stack helper class calls SkCanvas::restoreToCount when SkAutoCanvasRestore
+    goes out of scope. Use this to guarantee that the canvas is restored to a known
+    state.
+*/
+class SkAutoCanvasRestore {
+public:
+
+    /** Preserves SkCanvas::save() count. Optionally saves SkCanvas clip and SkCanvas matrix.
+
+        @param canvas  SkCanvas to guard
+        @param doSave  call SkCanvas::save()
+        @return        utility to restore SkCanvas state on destructor
+    */
+    SkAutoCanvasRestore(SkCanvas* canvas, bool doSave) : fCanvas(canvas), fSaveCount(0) {
+        if (fCanvas) {
+            fSaveCount = canvas->getSaveCount();
+            if (doSave) {
+                canvas->save();
+            }
+        }
+    }
+
+    /** Restores SkCanvas to saved state. Destructor is called when container goes out of
+        scope.
+    */
+    ~SkAutoCanvasRestore() {
+        if (fCanvas) {
+            fCanvas->restoreToCount(fSaveCount);
+        }
+    }
+
+    /** Restores SkCanvas to saved state immediately. Subsequent calls and
+        ~SkAutoCanvasRestore() have no effect.
+    */
+    void restore() {
+        if (fCanvas) {
+            fCanvas->restoreToCount(fSaveCount);
+            fCanvas = nullptr;
+        }
+    }
+
+private:
+    SkCanvas*   fCanvas;
+    int         fSaveCount;
+
+    SkAutoCanvasRestore(SkAutoCanvasRestore&&) = delete;
+    SkAutoCanvasRestore(const SkAutoCanvasRestore&) = delete;
+    SkAutoCanvasRestore& operator=(SkAutoCanvasRestore&&) = delete;
+    SkAutoCanvasRestore& operator=(const SkAutoCanvasRestore&) = delete;
+};
+
+#endif