Update documentation around drawBitmap and shaders

include/core/SkCanvas.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 SkCanvas_DEFINED
@@ skipping 654 matching lines @@
         @param paint    The paint used to draw the path
     */
     virtual void drawPath(const SkPath& path, const SkPaint& paint);
 
     /** Draw the specified bitmap, with its top/left corner at (x,y), using the
         specified paint, transformed by the current matrix. Note: if the paint
         contains a maskfilter that generates a mask which extends beyond the
         bitmap's original width/height, then the bitmap will be drawn as if it
         were in a Shader with CLAMP mode. Thus the color outside of the original
         width/height will be the edge color replicated.
+
+        If a shader is present on the paint it will be ignored, except in the
+        case where the bitmap is kA8_Config. In that case, the color is
+        generated by the shader.
+
         @param bitmap   The bitmap to be drawn
         @param left     The position of the left side of the bitmap being drawn
         @param top      The position of the top side of the bitmap being drawn
         @param paint    The paint used to draw the bitmap, or NULL
     */
     virtual void drawBitmap(const SkBitmap& bitmap, SkScalar left, SkScalar top,
                             const SkPaint* paint = NULL);
 
     enum DrawBitmapRectFlags {
         kNone_DrawBitmapRectFlag            = 0x0,
@@ skipping 498 matching lines @@
             fCanvas->endCommentGroup();
         }
     }
 
 private:
     SkCanvas* fCanvas;
 };
 #define SkAutoCommentBlock(...) SK_REQUIRE_LOCAL_VAR(SkAutoCommentBlock)
 
 #endif