Initial picture shader implementation

include/core/SkShader.h

 /*
  * 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 "SkBitmap.h"
 #include "SkFlattenable.h"
 #include "SkMask.h"
 #include "SkMatrix.h"
 #include "SkPaint.h"
 
 class SkPath;
+class SkPicture;
 class GrContext;
 class GrEffectRef;
 
 /** \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
@@ skipping 309 matching lines @@
      *  the paint.
      *
      *  @param src  The bitmap to use inside the shader
      *  @param tmx  The tiling mode to use when sampling the bitmap in the x-direction.
      *  @param tmy  The tiling mode to use when sampling the bitmap in the y-direction.
      *  @return     Returns a new shader object. Note: this function never returns null.
     */
     static SkShader* CreateBitmapShader(const SkBitmap& src,
                                         TileMode tmx, TileMode tmy);
 
+    /** Call this to create a new shader that will draw with the specified picture.
+     *
+     *  @param src  The picture to use inside the shader

[reed1, 2014/04/07 15:30:09]

// Do we ref() the argument?

[f(malita), 2014/04/07 15:45:29]

Done.

+     *  @param tmx  The tiling mode to use when sampling the bitmap in the x-direction.
+     *  @param tmy  The tiling mode to use when sampling the bitmap in the y-direction.
+     *  @return     Returns a new shader object. Note: this function never returns null.
+    */
+    static SkShader* CreatePictureShader(SkPicture& src, TileMode tmx, TileMode tmy);

[reed1, 2014/04/07 15:30:09]

I know drawPicture takes a &, but I think that is wacky. Everywhere else that we
ref() an arg we take a pointer. I think we should do that here as well.

[f(malita), 2014/04/07 15:45:29]

Done.

+
     SK_TO_STRING_VIRT()
     SK_DEFINE_FLATTENABLE_TYPE(SkShader)
 
 protected:
     enum MatrixClass {
         kLinear_MatrixClass,            // no perspective
         kFixedStepInX_MatrixClass,      // fast perspective, need to call fixedStepInX() each scanline
         kPerspective_MatrixClass        // slow perspective, need to mappoints each pixel
     };
     static MatrixClass ComputeMatrixClass(const SkMatrix&);
 
     // These can be called by your subclass after setContext() has been called
     uint8_t             getPaintAlpha() const { return fPaintAlpha; }
     const SkMatrix&     getTotalInverse() const { return fTotalInverse; }
     MatrixClass         getInverseClass() const { return (MatrixClass)fTotalInverseClass; }
 
     SkShader(SkReadBuffer& );
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 private:
     SkMatrix            fLocalMatrix;
     SkMatrix            fTotalInverse;
     uint8_t             fPaintAlpha;
     uint8_t             fTotalInverseClass;
     SkDEBUGCODE(SkBool8 fInSetContext;)
 
     typedef SkFlattenable INHERITED;
 };
 
 #endif