skia WIPjarred/canvas

1 files changed, 148 insertions, 0 deletions

diff --git a/src/deps/skia/include/core/SkShader.h b/src/deps/skia/include/core/SkShader.h
new file mode 100644
index 000000000..fba17f8ad
--- /dev/null
+++ b/src/deps/skia/include/core/SkShader.h
@@ -0,0 +1,148 @@
+/*
+ * 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 SkShader_DEFINED
+#define SkShader_DEFINED
+
+#include "include/core/SkBlendMode.h"
+#include "include/core/SkColor.h"
+#include "include/core/SkFlattenable.h"
+#include "include/core/SkImageInfo.h"
+#include "include/core/SkMatrix.h"
+#include "include/core/SkTileMode.h"
+
+class SkArenaAlloc;
+class SkBitmap;
+class SkBlender;
+class SkColorFilter;
+class SkColorSpace;
+class SkImage;
+class SkPath;
+class SkPicture;
+class SkRasterPipeline;
+class GrFragmentProcessor;
+
+/** \class SkShader
+ *
+ *  Shaders specify the source color(s) for what is being drawn. If a paint
+ *  has no shader, then the paint's color is used. If the paint has a
+ *  shader, then the shader's color(s) are use instead, but they are
+ *  modulated by the paint's alpha. This makes it easy to create a shader
+ *  once (e.g. bitmap tiling or gradient) and then change its transparency
+ *  w/o having to modify the original shader... only the paint's alpha needs
+ *  to be modified.
+ */
+class SK_API SkShader : public SkFlattenable {
+public:
+    /**
+     *  Returns true if the shader is guaranteed to produce only opaque
+     *  colors, subject to the SkPaint using the shader to apply an opaque
+     *  alpha value. Subclasses should override this to allow some
+     *  optimizations.
+     */
+    virtual bool isOpaque() const { return false; }
+
+    /**
+     *  Iff this shader is backed by a single SkImage, return its ptr (the caller must ref this
+     *  if they want to keep it longer than the lifetime of the shader). If not, return nullptr.
+     */
+    SkImage* isAImage(SkMatrix* localMatrix, SkTileMode xy[2]) const;
+
+    bool isAImage() const {
+        return this->isAImage(nullptr, (SkTileMode*)nullptr) != nullptr;
+    }
+
+    /**
+     *  If the shader subclass can be represented as a gradient, asAGradient
+     *  returns the matching GradientType enum (or kNone_GradientType if it
+     *  cannot). Also, if info is not null, asAGradient populates info with
+     *  the relevant (see below) parameters for the gradient.  fColorCount
+     *  is both an input and output parameter.  On input, it indicates how
+     *  many entries in fColors and fColorOffsets can be used, if they are
+     *  non-NULL.  After asAGradient has run, fColorCount indicates how
+     *  many color-offset pairs there are in the gradient.  If there is
+     *  insufficient space to store all of the color-offset pairs, fColors
+     *  and fColorOffsets will not be altered.  fColorOffsets specifies
+     *  where on the range of 0 to 1 to transition to the given color.
+     *  The meaning of fPoint and fRadius is dependant on the type of gradient.
+     *
+     *  None:
+     *      info is ignored.
+     *  Color:
+     *      fColorOffsets[0] is meaningless.
+     *  Linear:
+     *      fPoint[0] and fPoint[1] are the end-points of the gradient
+     *  Radial:
+     *      fPoint[0] and fRadius[0] are the center and radius
+     *  Conical:
+     *      fPoint[0] and fRadius[0] are the center and radius of the 1st circle
+     *      fPoint[1] and fRadius[1] are the center and radius of the 2nd circle
+     *  Sweep:
+     *      fPoint[0] is the center of the sweep.
+     */
+
+    enum GradientType {
+        kNone_GradientType,
+        kColor_GradientType,
+        kLinear_GradientType,
+        kRadial_GradientType,
+        kSweep_GradientType,
+        kConical_GradientType,
+        kLast_GradientType = kConical_GradientType,
+    };
+
+    struct GradientInfo {
+        int         fColorCount;    //!< In-out parameter, specifies passed size
+                                    //   of fColors/fColorOffsets on input, and
+                                    //   actual number of colors/offsets on
+                                    //   output.
+        SkColor*    fColors;        //!< The colors in the gradient.
+        SkScalar*   fColorOffsets;  //!< The unit offset for color transitions.
+        SkPoint     fPoint[2];      //!< Type specific, see above.
+        SkScalar    fRadius[2];     //!< Type specific, see above.
+        SkTileMode  fTileMode;
+        uint32_t    fGradientFlags; //!< see SkGradientShader::Flags
+    };
+
+    // DEPRECATED. skbug.com/8941
+    virtual GradientType asAGradient(GradientInfo* info) const;
+
+    //////////////////////////////////////////////////////////////////////////
+    //  Methods to create combinations or variants of shaders
+
+    /**
+     *  Return a shader that will apply the specified localMatrix to this shader.
+     *  The specified matrix will be applied before any matrix associated with this shader.
+     */
+    sk_sp<SkShader> makeWithLocalMatrix(const SkMatrix&) const;
+
+    /**
+     *  Create a new shader that produces the same colors as invoking this shader and then applying
+     *  the colorfilter.
+     */
+    sk_sp<SkShader> makeWithColorFilter(sk_sp<SkColorFilter>) const;
+
+private:
+    SkShader() = default;
+    friend class SkShaderBase;
+
+    using INHERITED = SkFlattenable;
+};
+
+class SK_API SkShaders {
+public:
+    static sk_sp<SkShader> Empty();
+    static sk_sp<SkShader> Color(SkColor);
+    static sk_sp<SkShader> Color(const SkColor4f&, sk_sp<SkColorSpace>);
+    static sk_sp<SkShader> Blend(SkBlendMode mode, sk_sp<SkShader> dst, sk_sp<SkShader> src);
+    static sk_sp<SkShader> Blend(sk_sp<SkBlender>, sk_sp<SkShader> dst, sk_sp<SkShader> src);
+
+private:
+    SkShaders() = delete;
+};
+
+#endif