add optional origin parameter to accessTopLayerPixels

BUG=skia:
R=bsalomon@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/244763004

git-svn-id: http://skia.googlecode.com/svn/trunk@14290 2bbb7eff-a529-9590-31e7-b0007b416f81

diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index 6a15c04..0a81969 100644 (file)
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -206,15 +206,14 @@ public:
      *  If the canvas has writable pixels in its top layer (and is not recording to a picture
      *  or other non-raster target) and has direct access to its pixels (i.e. they are in
      *  local RAM) return the address of those pixels, and if not null,
-     *  return the ImageInfo and rowBytes. The returned address is only valid
+     *  return the ImageInfo, rowBytes and origin. The returned address is only valid
      *  while the canvas object is in scope and unchanged. Any API calls made on
      *  canvas (or its parent surface if any) will invalidate the
      *  returned address (and associated information).
      *
-     *  On failure, returns NULL and the info and rowBytes parameters are
-     *  ignored.
+     *  On failure, returns NULL and the info, rowBytes, and origin parameters are ignored.
      */
-    void* accessTopLayerPixels(SkImageInfo* info, size_t* rowBytes);
+    void* accessTopLayerPixels(SkImageInfo* info, size_t* rowBytes, SkIPoint* origin = NULL);
 
     /**
      *  If the canvas has readable pixels in its base layer (and is not recording to a picture

diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index c57ae9a..e8da129 100644 (file)
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -1106,8 +1106,12 @@ const void* SkCanvas::onPeekPixels(SkImageInfo* info, size_t* rowBytes) {
     return dev ? dev->peekPixels(info, rowBytes) : NULL;
 }
 
-void* SkCanvas::accessTopLayerPixels(SkImageInfo* info, size_t* rowBytes) {
-    return this->onAccessTopLayerPixels(info, rowBytes);
+void* SkCanvas::accessTopLayerPixels(SkImageInfo* info, size_t* rowBytes, SkIPoint* origin) {
+    void* pixels = this->onAccessTopLayerPixels(info, rowBytes);
+    if (pixels && origin) {
+        *origin = this->getTopDevice(false)->getOrigin();
+    }
+    return pixels;
 }
 
 void* SkCanvas::onAccessTopLayerPixels(SkImageInfo* info, size_t* rowBytes) {