add localmatrix-shader

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
@@ skipping 383 matching lines @@
      *              is incremented). The SkPicture must not be changed after
      *              successfully creating a picture shader.
      *              FIXME: src cannot be const due to SkCanvas::drawPicture
      *  @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,
                                          const SkMatrix* localMatrix = NULL);
 
+    /**
+     *  Return a shader that will apply the specified localMatrix to the proxy shader.
+     *  The specified matrix will be applied before any matrix associated with the proxy.
+     *
+     *  Note: ownership of the proxy is not transferred (though a ref is taken).
+     */
+    static SkShader* CreateLocalMatrixShader(SkShader* proxy, const SkMatrix& localMatrix);
+
+    /**
+     *  If this shader can be represented by another shader + a localMatrix, return that shader
+     *  and, if not NULL, the localMatrix. If not, return NULL and ignore the localMatrix parameter.
+     *
+     *  Note: the returned shader (if not NULL) will have been ref'd, and it is the responsibility
+     *  of the caller to balance that with unref() when they are done.
+     */
+    virtual SkShader* refAsALocalMatrixShader(SkMatrix* localMatrix) const;
+
     SK_TO_STRING_VIRT()
     SK_DEFINE_FLATTENABLE_TYPE(SkShader)
 
 protected:
     SkShader(SkReadBuffer& );
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
     bool computeTotalInverse(const ContextRec&, SkMatrix* totalInverse) const;
 
     /**
      *  Your subclass must also override contextSize() if it overrides onCreateContext().
      *  Base class impl returns NULL.
      */
     virtual Context* onCreateContext(const ContextRec&, void* storage) const;
 
 private:
     SkMatrix fLocalMatrix;
 
     typedef SkFlattenable INHERITED;
 };
 
 #endif