skia WIPjarred/canvas

1 files changed, 1079 insertions, 0 deletions

diff --git a/src/deps/skia/include/core/SkSurface.h b/src/deps/skia/include/core/SkSurface.h
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+++ b/src/deps/skia/include/core/SkSurface.h
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+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkSurface_DEFINED
+#define SkSurface_DEFINED
+
+#include "include/core/SkImage.h"
+#include "include/core/SkPixmap.h"
+#include "include/core/SkRefCnt.h"
+#include "include/core/SkSurfaceProps.h"
+
+#if SK_SUPPORT_GPU
+#include "include/gpu/GrTypes.h"
+#endif
+
+#if defined(SK_BUILD_FOR_ANDROID) && __ANDROID_API__ >= 26
+#include <android/hardware_buffer.h>
+#endif
+
+#ifdef SK_METAL
+#include "include/gpu/mtl/GrMtlTypes.h"
+#endif
+
+class SkCanvas;
+class SkDeferredDisplayList;
+class SkPaint;
+class SkSurfaceCharacterization;
+class GrBackendRenderTarget;
+class GrBackendSemaphore;
+class GrBackendSurfaceMutableState;
+class GrBackendTexture;
+class GrDirectContext;
+class GrRecordingContext;
+class GrRenderTarget;
+enum GrSurfaceOrigin: int;
+
+/** \class SkSurface
+    SkSurface is responsible for managing the pixels that a canvas draws into. The pixels can be
+    allocated either in CPU memory (a raster surface) or on the GPU (a GrRenderTarget surface).
+    SkSurface takes care of allocating a SkCanvas that will draw into the surface. Call
+    surface->getCanvas() to use that canvas (but don't delete it, it is owned by the surface).
+    SkSurface always has non-zero dimensions. If there is a request for a new surface, and either
+    of the requested dimensions are zero, then nullptr will be returned.
+*/
+class SK_API SkSurface : public SkRefCnt {
+public:
+
+    /** Allocates raster SkSurface. SkCanvas returned by SkSurface draws directly into pixels.
+
+        SkSurface is returned if all parameters are valid.
+        Valid parameters include:
+        info dimensions are greater than zero;
+        info contains SkColorType and SkAlphaType supported by raster surface;
+        pixels is not nullptr;
+        rowBytes is large enough to contain info width pixels of SkColorType.
+
+        Pixel buffer size should be info height times computed rowBytes.
+        Pixels are not initialized.
+        To access pixels after drawing, peekPixels() or readPixels().
+
+        @param imageInfo     width, height, SkColorType, SkAlphaType, SkColorSpace,
+                             of raster surface; width and height must be greater than zero
+        @param pixels        pointer to destination pixels buffer
+        @param rowBytes      interval from one SkSurface row to the next
+        @param surfaceProps  LCD striping orientation and setting for device independent fonts;
+                             may be nullptr
+        @return              SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRasterDirect(const SkImageInfo& imageInfo, void* pixels,
+                                             size_t rowBytes,
+                                             const SkSurfaceProps* surfaceProps = nullptr);
+
+    static sk_sp<SkSurface> MakeRasterDirect(const SkPixmap& pm,
+                                             const SkSurfaceProps* props = nullptr) {
+        return MakeRasterDirect(pm.info(), pm.writable_addr(), pm.rowBytes(), props);
+    }
+
+    /** Allocates raster SkSurface. SkCanvas returned by SkSurface draws directly into pixels.
+        releaseProc is called with pixels and context when SkSurface is deleted.
+
+        SkSurface is returned if all parameters are valid.
+        Valid parameters include:
+        info dimensions are greater than zero;
+        info contains SkColorType and SkAlphaType supported by raster surface;
+        pixels is not nullptr;
+        rowBytes is large enough to contain info width pixels of 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 imageInfo     width, height, SkColorType, SkAlphaType, SkColorSpace,
+                             of raster surface; width and height must be greater than zero
+        @param pixels        pointer to destination pixels buffer
+        @param rowBytes      interval from one SkSurface row to the next
+        @param releaseProc   called when SkSurface is deleted; may be nullptr
+        @param context       passed to releaseProc; may be nullptr
+        @param surfaceProps  LCD striping orientation and setting for device independent fonts;
+                             may be nullptr
+        @return              SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRasterDirectReleaseProc(const SkImageInfo& imageInfo, void* pixels,
+                                    size_t rowBytes,
+                                    void (*releaseProc)(void* pixels, void* context),
+                                    void* context, const SkSurfaceProps* surfaceProps = nullptr);
+
+    /** Allocates raster SkSurface. SkCanvas returned by SkSurface draws directly into pixels.
+        Allocates and zeroes pixel memory. Pixel memory size is imageInfo.height() times
+        rowBytes, or times imageInfo.minRowBytes() if rowBytes is zero.
+        Pixel memory is deleted when SkSurface is deleted.
+
+        SkSurface is returned if all parameters are valid.
+        Valid parameters include:
+        info dimensions are greater than zero;
+        info contains SkColorType and SkAlphaType supported by raster surface;
+        rowBytes is large enough to contain info width pixels of SkColorType, or is zero.
+
+        If rowBytes is zero, a suitable value will be chosen internally.
+
+        @param imageInfo     width, height, SkColorType, SkAlphaType, SkColorSpace,
+                             of raster surface; width and height must be greater than zero
+        @param rowBytes      interval from one SkSurface row to the next; may be zero
+        @param surfaceProps  LCD striping orientation and setting for device independent fonts;
+                             may be nullptr
+        @return              SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRaster(const SkImageInfo& imageInfo, size_t rowBytes,
+                                       const SkSurfaceProps* surfaceProps);
+
+    /** Allocates raster SkSurface. SkCanvas returned by SkSurface draws directly into pixels.
+        Allocates and zeroes pixel memory. Pixel memory size is imageInfo.height() times
+        imageInfo.minRowBytes().
+        Pixel memory is deleted when SkSurface is deleted.
+
+        SkSurface is returned if all parameters are valid.
+        Valid parameters include:
+        info dimensions are greater than zero;
+        info contains SkColorType and SkAlphaType supported by raster surface.
+
+        @param imageInfo  width, height, SkColorType, SkAlphaType, SkColorSpace,
+                          of raster surface; width and height must be greater than zero
+        @param props      LCD striping orientation and setting for device independent fonts;
+                          may be nullptr
+        @return           SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRaster(const SkImageInfo& imageInfo,
+                                       const SkSurfaceProps* props = nullptr) {
+        return MakeRaster(imageInfo, 0, props);
+    }
+
+    /** Allocates raster SkSurface. SkCanvas returned by SkSurface draws directly into pixels.
+        Allocates and zeroes pixel memory. Pixel memory size is height times width times
+        four. Pixel memory is deleted when SkSurface is deleted.
+
+        Internally, sets SkImageInfo to width, height, native color type, and
+        kPremul_SkAlphaType.
+
+        SkSurface is returned if width and height are greater than zero.
+
+        Use to create SkSurface that matches SkPMColor, the native pixel arrangement on
+        the platform. SkSurface drawn to output device skips converting its pixel format.
+
+        @param width         pixel column count; must be greater than zero
+        @param height        pixel row count; must be greater than zero
+        @param surfaceProps  LCD striping orientation and setting for device independent
+                             fonts; may be nullptr
+        @return              SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRasterN32Premul(int width, int height,
+                                                const SkSurfaceProps* surfaceProps = nullptr);
+
+    /** Caller data passed to RenderTarget/TextureReleaseProc; may be nullptr. */
+    typedef void* ReleaseContext;
+
+    /** User function called when supplied render target may be deleted. */
+    typedef void (*RenderTargetReleaseProc)(ReleaseContext releaseContext);
+
+    /** User function called when supplied texture may be deleted. */
+    typedef void (*TextureReleaseProc)(ReleaseContext releaseContext);
+
+    /** Wraps a GPU-backed texture into SkSurface. Caller must ensure the texture is
+        valid for the lifetime of returned SkSurface. If sampleCnt greater than zero,
+        creates an intermediate MSAA SkSurface which is used for drawing backendTexture.
+
+        SkSurface is returned if all parameters are valid. backendTexture is valid if
+        its pixel configuration agrees with colorSpace and context; for instance, if
+        backendTexture has an sRGB configuration, then context must support sRGB,
+        and colorSpace must be present. Further, backendTexture width and height must
+        not exceed context capabilities, and the context must be able to support
+        back-end textures.
+
+        Upon success textureReleaseProc is called when it is safe to delete the texture in the
+        backend API (accounting only for use of the texture by this surface). If SkSurface creation
+        fails textureReleaseProc is called before this function returns.
+
+        If SK_SUPPORT_GPU is defined as zero, has no effect and returns nullptr.
+
+        @param context             GPU context
+        @param backendTexture      texture residing on GPU
+        @param sampleCnt           samples per pixel, or 0 to disable full scene anti-aliasing
+        @param colorSpace          range of colors; may be nullptr
+        @param surfaceProps        LCD striping orientation and setting for device independent
+                                   fonts; may be nullptr
+        @param textureReleaseProc  function called when texture can be released
+        @param releaseContext      state passed to textureReleaseProc
+        @return                    SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeFromBackendTexture(GrRecordingContext* context,
+                                                   const GrBackendTexture& backendTexture,
+                                                   GrSurfaceOrigin origin, int sampleCnt,
+                                                   SkColorType colorType,
+                                                   sk_sp<SkColorSpace> colorSpace,
+                                                   const SkSurfaceProps* surfaceProps,
+                                                   TextureReleaseProc textureReleaseProc = nullptr,
+                                                   ReleaseContext releaseContext = nullptr);
+
+    /** Wraps a GPU-backed buffer into SkSurface. Caller must ensure backendRenderTarget
+        is valid for the lifetime of returned SkSurface.
+
+        SkSurface is returned if all parameters are valid. backendRenderTarget is valid if
+        its pixel configuration agrees with colorSpace and context; for instance, if
+        backendRenderTarget has an sRGB configuration, then context must support sRGB,
+        and colorSpace must be present. Further, backendRenderTarget width and height must
+        not exceed context capabilities, and the context must be able to support
+        back-end render targets.
+
+        Upon success releaseProc is called when it is safe to delete the render target in the
+        backend API (accounting only for use of the render target by this surface). If SkSurface
+        creation fails releaseProc is called before this function returns.
+
+        If SK_SUPPORT_GPU is defined as zero, has no effect and returns nullptr.
+
+        @param context                  GPU context
+        @param backendRenderTarget      GPU intermediate memory buffer
+        @param colorSpace               range of colors
+        @param surfaceProps             LCD striping orientation and setting for device independent
+                                        fonts; may be nullptr
+        @param releaseProc              function called when backendRenderTarget can be released
+        @param releaseContext           state passed to releaseProc
+        @return                         SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeFromBackendRenderTarget(GrRecordingContext* context,
+                                                const GrBackendRenderTarget& backendRenderTarget,
+                                                GrSurfaceOrigin origin,
+                                                SkColorType colorType,
+                                                sk_sp<SkColorSpace> colorSpace,
+                                                const SkSurfaceProps* surfaceProps,
+                                                RenderTargetReleaseProc releaseProc = nullptr,
+                                                ReleaseContext releaseContext = nullptr);
+
+    /** Returns SkSurface on GPU indicated by context. Allocates memory for
+        pixels, based on the width, height, and SkColorType in SkImageInfo.  budgeted
+        selects whether allocation for pixels is tracked by context. imageInfo
+        describes the pixel format in SkColorType, and transparency in
+        SkAlphaType, and color matching in SkColorSpace.
+
+        sampleCount requests the number of samples per pixel.
+        Pass zero to disable multi-sample anti-aliasing.  The request is rounded
+        up to the next supported count, or rounded down if it is larger than the
+        maximum supported count.
+
+        surfaceOrigin pins either the top-left or the bottom-left corner to the origin.
+
+        shouldCreateWithMips hints that SkImage returned by makeImageSnapshot() is mip map.
+
+        If SK_SUPPORT_GPU is defined as zero, has no effect and returns nullptr.
+
+        @param context               GPU context
+        @param imageInfo             width, height, SkColorType, SkAlphaType, SkColorSpace;
+                                     width, or height, or both, may be zero
+        @param sampleCount           samples per pixel, or 0 to disable full scene anti-aliasing
+        @param surfaceProps          LCD striping orientation and setting for device independent
+                                     fonts; may be nullptr
+        @param shouldCreateWithMips  hint that SkSurface will host mip map images
+        @return                      SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRenderTarget(GrRecordingContext* context, SkBudgeted budgeted,
+                                             const SkImageInfo& imageInfo,
+                                             int sampleCount, GrSurfaceOrigin surfaceOrigin,
+                                             const SkSurfaceProps* surfaceProps,
+                                             bool shouldCreateWithMips = false);
+
+    /** Returns SkSurface on GPU indicated by context. Allocates memory for
+        pixels, based on the width, height, and SkColorType in SkImageInfo.  budgeted
+        selects whether allocation for pixels is tracked by context. imageInfo
+        describes the pixel format in SkColorType, and transparency in
+        SkAlphaType, and color matching in SkColorSpace.
+
+        sampleCount requests the number of samples per pixel.
+        Pass zero to disable multi-sample anti-aliasing.  The request is rounded
+        up to the next supported count, or rounded down if it is larger than the
+        maximum supported count.
+
+        SkSurface bottom-left corner is pinned to the origin.
+
+        @param context      GPU context
+        @param imageInfo    width, height, SkColorType, SkAlphaType, SkColorSpace,
+                            of raster surface; width, or height, or both, may be zero
+        @param sampleCount  samples per pixel, or 0 to disable multi-sample anti-aliasing
+        @param surfaceProps LCD striping orientation and setting for device independent
+                            fonts; may be nullptr
+        @return             SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRenderTarget(GrRecordingContext* context, SkBudgeted budgeted,
+                                             const SkImageInfo& imageInfo, int sampleCount,
+                                             const SkSurfaceProps* surfaceProps) {
+#if SK_SUPPORT_GPU
+        return MakeRenderTarget(context, budgeted, imageInfo, sampleCount,
+                                kBottomLeft_GrSurfaceOrigin, surfaceProps);
+#else
+        // TODO(kjlubick, scroggo) Remove this once Android is updated.
+        return nullptr;
+#endif
+    }
+
+    /** Returns SkSurface on GPU indicated by context. Allocates memory for
+        pixels, based on the width, height, and SkColorType in SkImageInfo.  budgeted
+        selects whether allocation for pixels is tracked by context. imageInfo
+        describes the pixel format in SkColorType, and transparency in
+        SkAlphaType, and color matching in SkColorSpace.
+
+        SkSurface bottom-left corner is pinned to the origin.
+
+        @param context    GPU context
+        @param imageInfo  width, height, SkColorType, SkAlphaType, SkColorSpace,
+                          of raster surface; width, or height, or both, may be zero
+        @return           SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRenderTarget(GrRecordingContext* context, SkBudgeted budgeted,
+                                             const SkImageInfo& imageInfo) {
+#if SK_SUPPORT_GPU
+        if (!imageInfo.width() || !imageInfo.height()) {
+            return nullptr;
+        }
+        return MakeRenderTarget(context, budgeted, imageInfo, 0, kBottomLeft_GrSurfaceOrigin,
+                                nullptr);
+#else
+        // TODO(kjlubick, scroggo) Remove this once Android is updated.
+        return nullptr;
+#endif
+    }
+
+    /** Returns SkSurface on GPU indicated by context that is compatible with the provided
+        characterization. budgeted selects whether allocation for pixels is tracked by context.
+
+        @param context           GPU context
+        @param characterization  description of the desired SkSurface
+        @return                  SkSurface if all parameters are valid; otherwise, nullptr
+    */
+    static sk_sp<SkSurface> MakeRenderTarget(GrRecordingContext* context,
+                                             const SkSurfaceCharacterization& characterization,
+                                             SkBudgeted budgeted);
+
+
+#if defined(SK_BUILD_FOR_ANDROID) && __ANDROID_API__ >= 26
+    /** Private.
+        Creates SkSurface from Android hardware buffer.
+        Returned SkSurface takes a reference on the buffer. The ref on the buffer will be released
+        when the SkSurface is destroyed and there is no pending work on the GPU involving the
+        buffer.
+
+        Only available on Android, when __ANDROID_API__ is defined to be 26 or greater.
+
+        Currently this is only supported for buffers that can be textured as well as rendered to.
+        In other words that must have both AHARDWAREBUFFER_USAGE_GPU_COLOR_OUTPUT and
+        AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE usage bits.
+
+        @param context         GPU context
+        @param hardwareBuffer  AHardwareBuffer Android hardware buffer
+        @param colorSpace      range of colors; may be nullptr
+        @param surfaceProps    LCD striping orientation and setting for device independent
+                               fonts; may be nullptr
+        @param fromWindow      Whether or not the AHardwareBuffer is part of an Android Window.
+                               Currently only used with Vulkan backend.
+        @return                created SkSurface, or nullptr
+    */
+    static sk_sp<SkSurface> MakeFromAHardwareBuffer(GrDirectContext* context,
+                                                    AHardwareBuffer* hardwareBuffer,
+                                                    GrSurfaceOrigin origin,
+                                                    sk_sp<SkColorSpace> colorSpace,
+                                                    const SkSurfaceProps* surfaceProps
+#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
+                                                    , bool fromWindow = false
+#endif  // SK_BUILD_FOR_ANDROID_FRAMEWORK
+                                                    );
+#endif
+
+#ifdef SK_METAL
+    /** Creates SkSurface from CAMetalLayer.
+        Returned SkSurface takes a reference on the CAMetalLayer. The ref on the layer will be
+        released when the SkSurface is destroyed.
+
+        Only available when Metal API is enabled.
+
+        Will grab the current drawable from the layer and use its texture as a backendRT to
+        create a renderable surface.
+
+        @param context         GPU context
+        @param layer           GrMTLHandle (expected to be a CAMetalLayer*)
+        @param sampleCnt       samples per pixel, or 0 to disable full scene anti-aliasing
+        @param colorSpace      range of colors; may be nullptr
+        @param surfaceProps    LCD striping orientation and setting for device independent
+                               fonts; may be nullptr
+        @param drawable        Pointer to drawable to be filled in when this surface is
+                               instantiated; may not be nullptr
+        @return                created SkSurface, or nullptr
+     */
+    static sk_sp<SkSurface> MakeFromCAMetalLayer(GrRecordingContext* context,
+                                                 GrMTLHandle layer,
+                                                 GrSurfaceOrigin origin,
+                                                 int sampleCnt,
+                                                 SkColorType colorType,
+                                                 sk_sp<SkColorSpace> colorSpace,
+                                                 const SkSurfaceProps* surfaceProps,
+                                                 GrMTLHandle* drawable)
+                                                 SK_API_AVAILABLE_CA_METAL_LAYER;
+
+    /** Creates SkSurface from MTKView.
+        Returned SkSurface takes a reference on the MTKView. The ref on the layer will be
+        released when the SkSurface is destroyed.
+
+        Only available when Metal API is enabled.
+
+        Will grab the current drawable from the layer and use its texture as a backendRT to
+        create a renderable surface.
+
+        @param context         GPU context
+        @param layer           GrMTLHandle (expected to be a MTKView*)
+        @param sampleCnt       samples per pixel, or 0 to disable full scene anti-aliasing
+        @param colorSpace      range of colors; may be nullptr
+        @param surfaceProps    LCD striping orientation and setting for device independent
+                               fonts; may be nullptr
+        @return                created SkSurface, or nullptr
+     */
+    static sk_sp<SkSurface> MakeFromMTKView(GrRecordingContext* context,
+                                            GrMTLHandle mtkView,
+                                            GrSurfaceOrigin origin,
+                                            int sampleCnt,
+                                            SkColorType colorType,
+                                            sk_sp<SkColorSpace> colorSpace,
+                                            const SkSurfaceProps* surfaceProps)
+                                            SK_API_AVAILABLE(macos(10.11), ios(9.0));
+#endif
+
+    /** Is this surface compatible with the provided characterization?
+
+        This method can be used to determine if an existing SkSurface is a viable destination
+        for an SkDeferredDisplayList.
+
+        @param characterization  The characterization for which a compatibility check is desired
+        @return                  true if this surface is compatible with the characterization;
+                                 false otherwise
+    */
+    bool isCompatible(const SkSurfaceCharacterization& characterization) const;
+
+    /** Returns SkSurface without backing pixels. Drawing to SkCanvas returned from SkSurface
+        has no effect. Calling makeImageSnapshot() on returned SkSurface returns nullptr.
+
+        @param width   one or greater
+        @param height  one or greater
+        @return        SkSurface if width and height are positive; otherwise, nullptr
+
+        example: https://fiddle.skia.org/c/@Surface_MakeNull
+    */
+    static sk_sp<SkSurface> MakeNull(int width, int height);
+
+    /** Returns pixel count in each row; may be zero or greater.
+
+        @return  number of pixel columns
+    */
+    int width() const { return fWidth; }
+
+    /** Returns pixel row count; may be zero or greater.
+
+        @return  number of pixel rows
+    */
+    int height() const { return fHeight; }
+
+    /** Returns an ImageInfo describing the surface.
+     */
+    SkImageInfo imageInfo();
+
+    /** Returns unique value identifying the content of SkSurface. Returned value changes
+        each time the content changes. Content is changed by drawing, or by calling
+        notifyContentWillChange().
+
+        @return  unique content identifier
+
+        example: https://fiddle.skia.org/c/@Surface_notifyContentWillChange
+    */
+    uint32_t generationID();
+
+    /** \enum SkSurface::ContentChangeMode
+        ContentChangeMode members are parameters to notifyContentWillChange().
+    */
+    enum ContentChangeMode {
+        kDiscard_ContentChangeMode, //!< discards surface on change
+        kRetain_ContentChangeMode,  //!< preserves surface on change
+    };
+
+    /** Notifies that SkSurface contents will be changed by code outside of Skia.
+        Subsequent calls to generationID() return a different value.
+
+        TODO: Can kRetain_ContentChangeMode be deprecated?
+
+        example: https://fiddle.skia.org/c/@Surface_notifyContentWillChange
+    */
+    void notifyContentWillChange(ContentChangeMode mode);
+
+    /** Returns the recording context being used by the SkSurface.
+
+        @return the recording context, if available; nullptr otherwise
+     */
+    GrRecordingContext* recordingContext();
+
+#if SK_SUPPORT_GPU
+    enum BackendHandleAccess {
+        kFlushRead_BackendHandleAccess,    //!< back-end object is readable
+        kFlushWrite_BackendHandleAccess,   //!< back-end object is writable
+        kDiscardWrite_BackendHandleAccess, //!< back-end object must be overwritten
+    };
+
+    /** Deprecated.
+    */
+    static const BackendHandleAccess kFlushRead_TextureHandleAccess =
+            kFlushRead_BackendHandleAccess;
+
+    /** Deprecated.
+    */
+    static const BackendHandleAccess kFlushWrite_TextureHandleAccess =
+            kFlushWrite_BackendHandleAccess;
+
+    /** Deprecated.
+    */
+    static const BackendHandleAccess kDiscardWrite_TextureHandleAccess =
+            kDiscardWrite_BackendHandleAccess;
+
+    /** Retrieves the back-end texture. If SkSurface has no back-end texture, an invalid
+        object is returned. Call GrBackendTexture::isValid to determine if the result
+        is valid.
+
+        The returned GrBackendTexture should be discarded if the SkSurface is drawn to or deleted.
+
+        @return                     GPU texture reference; invalid on failure
+    */
+    GrBackendTexture getBackendTexture(BackendHandleAccess backendHandleAccess);
+
+    /** Retrieves the back-end render target. If SkSurface has no back-end render target, an invalid
+        object is returned. Call GrBackendRenderTarget::isValid to determine if the result
+        is valid.
+
+        The returned GrBackendRenderTarget should be discarded if the SkSurface is drawn to
+        or deleted.
+
+        @return                     GPU render target reference; invalid on failure
+    */
+    GrBackendRenderTarget getBackendRenderTarget(BackendHandleAccess backendHandleAccess);
+
+    /** If the surface was made via MakeFromBackendTexture then it's backing texture may be
+        substituted with a different texture. The contents of the previous backing texture are
+        copied into the new texture. SkCanvas state is preserved. The original sample count is
+        used. The GrBackendFormat and dimensions of replacement texture must match that of
+        the original.
+
+        Upon success textureReleaseProc is called when it is safe to delete the texture in the
+        backend API (accounting only for use of the texture by this surface). If SkSurface creation
+        fails textureReleaseProc is called before this function returns.
+
+        @param backendTexture      the new backing texture for the surface
+        @param mode                Retain or discard current Content
+        @param textureReleaseProc  function called when texture can be released
+        @param releaseContext      state passed to textureReleaseProc
+     */
+    bool replaceBackendTexture(const GrBackendTexture& backendTexture,
+                               GrSurfaceOrigin origin,
+                               ContentChangeMode mode = kRetain_ContentChangeMode,
+                               TextureReleaseProc textureReleaseProc = nullptr,
+                               ReleaseContext releaseContext = nullptr);
+#endif
+
+    /** Returns SkCanvas that draws into SkSurface. Subsequent calls return the same SkCanvas.
+        SkCanvas returned is managed and owned by SkSurface, and is deleted when SkSurface
+        is deleted.
+
+        @return  drawing SkCanvas for SkSurface
+
+        example: https://fiddle.skia.org/c/@Surface_getCanvas
+    */
+    SkCanvas* getCanvas();
+
+    /** Returns a compatible SkSurface, or nullptr. Returned SkSurface contains
+        the same raster, GPU, or null properties as the original. Returned SkSurface
+        does not share the same pixels.
+
+        Returns nullptr if imageInfo width or height are zero, or if imageInfo
+        is incompatible with SkSurface.
+
+        @param imageInfo  width, height, SkColorType, SkAlphaType, SkColorSpace,
+                          of SkSurface; width and height must be greater than zero
+        @return           compatible SkSurface or nullptr
+
+        example: https://fiddle.skia.org/c/@Surface_makeSurface
+    */
+    sk_sp<SkSurface> makeSurface(const SkImageInfo& imageInfo);
+
+    /** Calls makeSurface(ImageInfo) with the same ImageInfo as this surface, but with the
+     *  specified width and height.
+     */
+    sk_sp<SkSurface> makeSurface(int width, int height);
+
+    /** Returns SkImage capturing SkSurface contents. Subsequent drawing to SkSurface contents
+        are not captured. SkImage allocation is accounted for if SkSurface was created with
+        SkBudgeted::kYes.
+
+        @return  SkImage initialized with SkSurface contents
+
+        example: https://fiddle.skia.org/c/@Surface_makeImageSnapshot
+    */
+    sk_sp<SkImage> makeImageSnapshot();
+
+    /**
+     *  Like the no-parameter version, this returns an image of the current surface contents.
+     *  This variant takes a rectangle specifying the subset of the surface that is of interest.
+     *  These bounds will be sanitized before being used.
+     *  - If bounds extends beyond the surface, it will be trimmed to just the intersection of
+     *    it and the surface.
+     *  - If bounds does not intersect the surface, then this returns nullptr.
+     *  - If bounds == the surface, then this is the same as calling the no-parameter variant.
+
+        example: https://fiddle.skia.org/c/@Surface_makeImageSnapshot_2
+     */
+    sk_sp<SkImage> makeImageSnapshot(const SkIRect& bounds);
+
+    /** Draws SkSurface contents to canvas, with its top-left corner at (x, y).
+
+        If SkPaint paint is not nullptr, apply SkColorFilter, alpha, SkImageFilter, and SkBlendMode.
+
+        @param canvas  SkCanvas drawn into
+        @param x       horizontal offset in SkCanvas
+        @param y       vertical offset in SkCanvas
+        @param sampling what technique to use when sampling the surface pixels
+        @param paint   SkPaint containing SkBlendMode, SkColorFilter, SkImageFilter,
+                       and so on; or nullptr
+
+        example: https://fiddle.skia.org/c/@Surface_draw
+    */
+    void draw(SkCanvas* canvas, SkScalar x, SkScalar y, const SkSamplingOptions& sampling,
+              const SkPaint* paint);
+
+    void draw(SkCanvas* canvas, SkScalar x, SkScalar y, const SkPaint* paint = nullptr) {
+        this->draw(canvas, x, y, SkSamplingOptions(), paint);
+    }
+
+    /** Copies SkSurface pixel address, row bytes, and SkImageInfo to SkPixmap, if address
+        is available, and returns true. If pixel address is not available, return
+        false and leave SkPixmap unchanged.
+
+        pixmap contents become invalid on any future change to SkSurface.
+
+        @param pixmap  storage for pixel state if pixels are readable; otherwise, ignored
+        @return        true if SkSurface has direct access to pixels
+
+        example: https://fiddle.skia.org/c/@Surface_peekPixels
+    */
+    bool peekPixels(SkPixmap* pixmap);
+
+    /** Copies SkRect of pixels to dst.
+
+        Source SkRect corners are (srcX, srcY) and SkSurface (width(), height()).
+        Destination SkRect corners are (0, 0) and (dst.width(), dst.height()).
+        Copies each readable pixel intersecting both rectangles, without scaling,
+        converting to dst.colorType() and dst.alphaType() if required.
+
+        Pixels are readable when SkSurface is raster, or backed by a GPU.
+
+        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. dst 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.
+        - SkPixmap pixels could not be allocated.
+        - dst.rowBytes() is too small to contain one row of pixels.
+
+        @param dst   storage for pixels copied from SkSurface
+        @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/@Surface_readPixels
+    */
+    bool readPixels(const SkPixmap& dst, int srcX, int srcY);
+
+    /** Copies SkRect of pixels from SkCanvas into dstPixels.
+
+        Source SkRect corners are (srcX, srcY) and SkSurface (width(), 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 SkSurface is raster, or backed by a GPU.
+
+        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.
+        - SkSurface pixels could not be converted to dstInfo.colorType() or dstInfo.alphaType().
+        - 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 SkSurface into bitmap.
+
+        Source SkRect corners are (srcX, srcY) and SkSurface (width(), 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 SkSurface is raster, or backed by a GPU.
+
+        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. dst 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.
+        - SkSurface pixels could not be converted to dst.colorType() or dst.alphaType().
+        - dst pixels could not be allocated.
+        - dst.rowBytes() is too small to contain one row of pixels.
+
+        @param dst   storage for pixels copied from SkSurface
+        @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/@Surface_readPixels_3
+    */
+    bool readPixels(const SkBitmap& dst, int srcX, int srcY);
+
+    using AsyncReadResult = SkImage::AsyncReadResult;
+
+    /** Client-provided context that is passed to client-provided ReadPixelsContext. */
+    using ReadPixelsContext = void*;
+
+    /**  Client-provided callback to asyncRescaleAndReadPixels() or
+         asyncRescaleAndReadPixelsYUV420() that is called when read result is ready or on failure.
+     */
+    using ReadPixelsCallback = void(ReadPixelsContext, std::unique_ptr<const AsyncReadResult>);
+
+    /** Controls the gamma that rescaling occurs in for asyncRescaleAndReadPixels() and
+        asyncRescaleAndReadPixelsYUV420().
+     */
+    using RescaleGamma = SkImage::RescaleGamma;
+    using RescaleMode  = SkImage::RescaleMode;
+
+    /** Makes surface pixel data available to caller, possibly asynchronously. It can also rescale
+        the surface pixels.
+
+        Currently asynchronous reads are only supported on the GPU backend and only when the
+        underlying 3D API supports transfer buffers and CPU/GPU synchronization primitives. In all
+        other cases this operates synchronously.
+
+        Data is read from the source sub-rectangle, is optionally converted to a linear gamma, is
+        rescaled to the size indicated by 'info', is then converted to the color space, color type,
+        and alpha type of 'info'. A 'srcRect' that is not contained by the bounds of the surface
+        causes failure.
+
+        When the pixel data is ready the caller's ReadPixelsCallback is called with a
+        AsyncReadResult containing pixel data in the requested color type, alpha type, and color
+        space. The AsyncReadResult will have count() == 1. Upon failure the callback is called
+        with nullptr for AsyncReadResult. For a GPU surface this flushes work but a submit must
+        occur to guarantee a finite time before the callback is called.
+
+        The data is valid for the lifetime of AsyncReadResult with the exception that if the
+        SkSurface is GPU-backed the data is immediately invalidated if the context is abandoned
+        or destroyed.
+
+        @param info            info of the requested pixels
+        @param srcRect         subrectangle of surface to read
+        @param rescaleGamma    controls whether rescaling is done in the surface's gamma or whether
+                               the source data is transformed to a linear gamma before rescaling.
+        @param rescaleMode     controls the technique of the rescaling
+        @param callback        function to call with result of the read
+        @param context         passed to callback
+     */
+    void asyncRescaleAndReadPixels(const SkImageInfo& info,
+                                   const SkIRect& srcRect,
+                                   RescaleGamma rescaleGamma,
+                                   RescaleMode rescaleMode,
+                                   ReadPixelsCallback callback,
+                                   ReadPixelsContext context);
+
+    /**
+        Similar to asyncRescaleAndReadPixels but performs an additional conversion to YUV. The
+        RGB->YUV conversion is controlled by 'yuvColorSpace'. The YUV data is returned as three
+        planes ordered y, u, v. The u and v planes are half the width and height of the resized
+        rectangle. The y, u, and v values are single bytes. Currently this fails if 'dstSize'
+        width and height are not even. A 'srcRect' that is not contained by the bounds of the
+        surface causes failure.
+
+        When the pixel data is ready the caller's ReadPixelsCallback is called with a
+        AsyncReadResult containing the planar data. The AsyncReadResult will have count() == 3.
+        Upon failure the callback is called with nullptr for AsyncReadResult. For a GPU surface this
+        flushes work but a submit must occur to guarantee a finite time before the callback is
+        called.
+
+        The data is valid for the lifetime of AsyncReadResult with the exception that if the
+        SkSurface is GPU-backed the data is immediately invalidated if the context is abandoned
+        or destroyed.
+
+        @param yuvColorSpace  The transformation from RGB to YUV. Applied to the resized image
+                              after it is converted to dstColorSpace.
+        @param dstColorSpace  The color space to convert the resized image to, after rescaling.
+        @param srcRect        The portion of the surface to rescale and convert to YUV planes.
+        @param dstSize        The size to rescale srcRect to
+        @param rescaleGamma   controls whether rescaling is done in the surface's gamma or whether
+                              the source data is transformed to a linear gamma before rescaling.
+        @param rescaleMode    controls the sampling technique of the rescaling
+        @param callback       function to call with the planar read result
+        @param context        passed to callback
+     */
+    void asyncRescaleAndReadPixelsYUV420(SkYUVColorSpace yuvColorSpace,
+                                         sk_sp<SkColorSpace> dstColorSpace,
+                                         const SkIRect& srcRect,
+                                         const SkISize& dstSize,
+                                         RescaleGamma rescaleGamma,
+                                         RescaleMode rescaleMode,
+                                         ReadPixelsCallback callback,
+                                         ReadPixelsContext context);
+
+    /** Copies SkRect of pixels from the src SkPixmap to the SkSurface.
+
+        Source SkRect corners are (0, 0) and (src.width(), src.height()).
+        Destination SkRect corners are (dstX, dstY) and
+        (dstX + Surface width(), dstY + Surface height()).
+
+        Copies each readable pixel intersecting both rectangles, without scaling,
+        converting to SkSurface colorType() and SkSurface alphaType() if required.
+
+        @param src   storage for pixels to copy to SkSurface
+        @param dstX  x-axis position relative to SkSurface to begin copy; may be negative
+        @param dstY  y-axis position relative to SkSurface to begin copy; may be negative
+
+        example: https://fiddle.skia.org/c/@Surface_writePixels
+    */
+    void writePixels(const SkPixmap& src, int dstX, int dstY);
+
+    /** Copies SkRect of pixels from the src SkBitmap to the SkSurface.
+
+        Source SkRect corners are (0, 0) and (src.width(), src.height()).
+        Destination SkRect corners are (dstX, dstY) and
+        (dstX + Surface width(), dstY + Surface height()).
+
+        Copies each readable pixel intersecting both rectangles, without scaling,
+        converting to SkSurface colorType() and SkSurface alphaType() if required.
+
+        @param src   storage for pixels to copy to SkSurface
+        @param dstX  x-axis position relative to SkSurface to begin copy; may be negative
+        @param dstY  y-axis position relative to SkSurface to begin copy; may be negative
+
+        example: https://fiddle.skia.org/c/@Surface_writePixels_2
+    */
+    void writePixels(const SkBitmap& src, int dstX, int dstY);
+
+    /** Returns SkSurfaceProps for surface.
+
+        @return  LCD striping orientation and setting for device independent fonts
+    */
+    const SkSurfaceProps& props() const { return fProps; }
+
+    /** Call to ensure all reads/writes of the surface have been issued to the underlying 3D API.
+        Skia will correctly order its own draws and pixel operations. This must to be used to ensure
+        correct ordering when the surface backing store is accessed outside Skia (e.g. direct use of
+        the 3D API or a windowing system). GrDirectContext has additional flush and submit methods
+        that apply to all surfaces and images created from a GrDirectContext. This is equivalent to
+        calling SkSurface::flush with a default GrFlushInfo followed by
+        GrDirectContext::submit(syncCpu).
+    */
+    void flushAndSubmit(bool syncCpu = false);
+
+    enum class BackendSurfaceAccess {
+        kNoAccess,  //!< back-end object will not be used by client
+        kPresent,   //!< back-end surface will be used for presenting to screen
+    };
+
+#if SK_SUPPORT_GPU
+    /** Issues pending SkSurface commands to the GPU-backed API objects and resolves any SkSurface
+        MSAA. A call to GrDirectContext::submit is always required to ensure work is actually sent
+        to the gpu. Some specific API details:
+            GL: Commands are actually sent to the driver, but glFlush is never called. Thus some
+                sync objects from the flush will not be valid until a submission occurs.
+
+            Vulkan/Metal/D3D/Dawn: Commands are recorded to the backend APIs corresponding command
+                buffer or encoder objects. However, these objects are not sent to the gpu until a
+                submission occurs.
+
+        The work that is submitted to the GPU will be dependent on the BackendSurfaceAccess that is
+        passed in.
+
+        If BackendSurfaceAccess::kNoAccess is passed in all commands will be issued to the GPU.
+
+        If BackendSurfaceAccess::kPresent is passed in and the backend API is not Vulkan, it is
+        treated the same as kNoAccess. If the backend API is Vulkan, the VkImage that backs the
+        SkSurface will be transferred back to its original queue. If the SkSurface was created by
+        wrapping a VkImage, the queue will be set to the queue which was originally passed in on
+        the GrVkImageInfo. Additionally, if the original queue was not external or foreign the
+        layout of the VkImage will be set to VK_IMAGE_LAYOUT_PRESENT_SRC_KHR.
+
+        The GrFlushInfo describes additional options to flush. Please see documentation at
+        GrFlushInfo for more info.
+
+        If the return is GrSemaphoresSubmitted::kYes, only initialized GrBackendSemaphores will be
+        submitted to the gpu during the next submit call (it is possible Skia failed to create a
+        subset of the semaphores). The client should not wait on these semaphores until after submit
+        has been called, but must keep them alive until then. If a submit flag was passed in with
+        the flush these valid semaphores can we waited on immediately. If this call returns
+        GrSemaphoresSubmitted::kNo, the GPU backend will not submit any semaphores to be signaled on
+        the GPU. Thus the client should not have the GPU wait on any of the semaphores passed in
+        with the GrFlushInfo. Regardless of whether semaphores were submitted to the GPU or not, the
+        client is still responsible for deleting any initialized semaphores.
+        Regardless of semaphore submission the context will still be flushed. It should be
+        emphasized that a return value of GrSemaphoresSubmitted::kNo does not mean the flush did not
+        happen. It simply means there were no semaphores submitted to the GPU. A caller should only
+        take this as a failure if they passed in semaphores to be submitted.
+
+        Pending surface commands are flushed regardless of the return result.
+
+        @param access  type of access the call will do on the backend object after flush
+        @param info    flush options
+    */
+    GrSemaphoresSubmitted flush(BackendSurfaceAccess access, const GrFlushInfo& info);
+
+    /** Issues pending SkSurface commands to the GPU-backed API objects and resolves any SkSurface
+        MSAA. A call to GrDirectContext::submit is always required to ensure work is actually sent
+        to the gpu. Some specific API details:
+            GL: Commands are actually sent to the driver, but glFlush is never called. Thus some
+                sync objects from the flush will not be valid until a submission occurs.
+
+            Vulkan/Metal/D3D/Dawn: Commands are recorded to the backend APIs corresponding command
+                buffer or encoder objects. However, these objects are not sent to the gpu until a
+                submission occurs.
+
+        The GrFlushInfo describes additional options to flush. Please see documentation at
+        GrFlushInfo for more info.
+
+        If a GrBackendSurfaceMutableState is passed in, at the end of the flush we will transition
+        the surface to be in the state requested by the GrBackendSurfaceMutableState. If the surface
+        (or SkImage or GrBackendSurface wrapping the same backend object) is used again after this
+        flush the state may be changed and no longer match what is requested here. This is often
+        used if the surface will be used for presenting or external use and the client wants backend
+        object to be prepped for that use. A finishedProc or semaphore on the GrFlushInfo will also
+        include the work for any requested state change.
+
+        If the backend API is Vulkan, the caller can set the GrBackendSurfaceMutableState's
+        VkImageLayout to VK_IMAGE_LAYOUT_UNDEFINED or queueFamilyIndex to VK_QUEUE_FAMILY_IGNORED to
+        tell Skia to not change those respective states.
+
+        If the return is GrSemaphoresSubmitted::kYes, only initialized GrBackendSemaphores will be
+        submitted to the gpu during the next submit call (it is possible Skia failed to create a
+        subset of the semaphores). The client should not wait on these semaphores until after submit
+        has been called, but must keep them alive until then. If a submit flag was passed in with
+        the flush these valid semaphores can we waited on immediately. If this call returns
+        GrSemaphoresSubmitted::kNo, the GPU backend will not submit any semaphores to be signaled on
+        the GPU. Thus the client should not have the GPU wait on any of the semaphores passed in
+        with the GrFlushInfo. Regardless of whether semaphores were submitted to the GPU or not, the
+        client is still responsible for deleting any initialized semaphores.
+        Regardleess of semaphore submission the context will still be flushed. It should be
+        emphasized that a return value of GrSemaphoresSubmitted::kNo does not mean the flush did not
+        happen. It simply means there were no semaphores submitted to the GPU. A caller should only
+        take this as a failure if they passed in semaphores to be submitted.
+
+        Pending surface commands are flushed regardless of the return result.
+
+        @param info    flush options
+        @param access  optional state change request after flush
+    */
+    GrSemaphoresSubmitted flush(const GrFlushInfo& info,
+                                const GrBackendSurfaceMutableState* newState = nullptr);
+#endif // SK_SUPPORT_GPU
+
+    void flush();
+
+    /** Inserts a list of GPU semaphores that the current GPU-backed API must wait on before
+        executing any more commands on the GPU for this surface. If this call returns false, then
+        the GPU back-end will not wait on any passed in semaphores, and the client will still own
+        the semaphores, regardless of the value of deleteSemaphoresAfterWait.
+
+        If deleteSemaphoresAfterWait is false then Skia will not delete the semaphores. In this case
+        it is the client's responsibility to not destroy or attempt to reuse the semaphores until it
+        knows that Skia has finished waiting on them. This can be done by using finishedProcs
+        on flush calls.
+
+        @param numSemaphores               size of waitSemaphores array
+        @param waitSemaphores              array of semaphore containers
+        @paramm deleteSemaphoresAfterWait  who owns and should delete the semaphores
+        @return                            true if GPU is waiting on semaphores
+    */
+    bool wait(int numSemaphores, const GrBackendSemaphore* waitSemaphores,
+              bool deleteSemaphoresAfterWait = true);
+
+    /** Initializes SkSurfaceCharacterization that can be used to perform GPU back-end
+        processing in a separate thread. Typically this is used to divide drawing
+        into multiple tiles. SkDeferredDisplayListRecorder records the drawing commands
+        for each tile.
+
+        Return true if SkSurface supports characterization. raster surface returns false.
+
+        @param characterization  properties for parallel drawing
+        @return                  true if supported
+
+        example: https://fiddle.skia.org/c/@Surface_characterize
+    */
+    bool characterize(SkSurfaceCharacterization* characterization) const;
+
+    /** Draws the deferred display list created via a SkDeferredDisplayListRecorder.
+        If the deferred display list is not compatible with this SkSurface, the draw is skipped
+        and false is return.
+
+        The xOffset and yOffset parameters are experimental and, if not both zero, will cause
+        the draw to be ignored.
+        When implemented, if xOffset or yOffset are non-zero, the DDL will be drawn offset by that
+        amount into the surface.
+
+        @param deferredDisplayList  drawing commands
+        @param xOffset              x-offset at which to draw the DDL
+        @param yOffset              y-offset at which to draw the DDL
+        @return                     false if deferredDisplayList is not compatible
+
+        example: https://fiddle.skia.org/c/@Surface_draw_2
+    */
+    bool draw(sk_sp<const SkDeferredDisplayList> deferredDisplayList,
+              int xOffset = 0,
+              int yOffset = 0);
+
+protected:
+    SkSurface(int width, int height, const SkSurfaceProps* surfaceProps);
+    SkSurface(const SkImageInfo& imageInfo, const SkSurfaceProps* surfaceProps);
+
+    // called by subclass if their contents have changed
+    void dirtyGenerationID() {
+        fGenerationID = 0;
+    }
+
+private:
+    const SkSurfaceProps fProps;
+    const int            fWidth;
+    const int            fHeight;
+    uint32_t             fGenerationID;
+
+    using INHERITED = SkRefCnt;
+};
+
+#endif