Initial picture shader implementation

src/core/SkPictureShader.h

Index: src/core/SkPictureShader.h
diff --git a/src/core/SkPictureShader.h b/src/core/SkPictureShader.h
new file mode 100644
index 0000000000000000000000000000000000000000..ea74b56d73d857394f9c20b227d41368f1623fa0
--- /dev/null
+++ b/src/core/SkPictureShader.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkPictureShader_DEFINED
+#define SkPictureShader_DEFINED
+
+#include "SkShader.h"
+
+class SkBitmap;
+class SkPicture;
+
+/*
+ * An SkPictureShader can be used to draw SkPicture-based patterns.
+ *
+ * The SkPicture is first rendered into a tile, which is then used to shade the area according
+ * to specified tiling rules.
+ */
+class SkPictureShader : public SkShader {
+public:
+    static SkPictureShader* Create(SkPicture*, TileMode, TileMode);
+    virtual ~SkPictureShader();
+
+    virtual bool setContext(const SkBitmap&, const SkPaint&, const SkMatrix&) SK_OVERRIDE;
+    virtual void endContext() SK_OVERRIDE;
+    virtual uint32_t getFlags() SK_OVERRIDE;
+
+    virtual ShadeProc asAShadeProc(void** ctx) SK_OVERRIDE;
+    virtual void shadeSpan(int x, int y, SkPMColor dstC[], int count) SK_OVERRIDE;
+    virtual void shadeSpan16(int x, int y, uint16_t dstC[], int count) SK_OVERRIDE;
+
+    SK_TO_STRING_OVERRIDE()
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPictureShader)
+
+#if SK_SUPPORT_GPU
+    GrEffectRef* asNewEffect(GrContext*, const SkPaint&) const SK_OVERRIDE;
+#endif
+
+protected:
+    SkPictureShader(SkReadBuffer&);
+    virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
+
+private:
+    SkPictureShader(SkPicture*, TileMode, TileMode);
+
+    bool buildBitmapShader(const SkMatrix&) const;
+
+    SkPicture*  fPicture;
+    TileMode    fTmx, fTmy;
+
+    mutable SkAutoTUnref<SkShader>  fCachedShader;
+    mutable SkSize                  fCachedTileScale;
+
+    typedef SkShader INHERITED;
+};
+
+#endif // SkPictureShader_DEFINED