Add support for reading the dst pixel value in an effect. Use in a new effect for the kDarken xfer mode.
The current implementation is to always make a copy of the entire dst before the draw.
It will only succeed if the RT is also a texture.
Obviously, there is lots of room for improvement.
Review URL: https://codereview.chromium.org/13314002
git-svn-id: http://skia.googlecode.com/svn/trunk@8449 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/GrTexture.h b/include/gpu/GrTexture.h
index c088bdd..5d8ecaa 100644
--- a/include/gpu/GrTexture.h
+++ b/include/gpu/GrTexture.h
@@ -10,6 +10,7 @@
#define GrTexture_DEFINED
#include "GrSurface.h"
+#include "SkPoint.h"
class GrRenderTarget;
class GrResourceKey;
@@ -166,4 +167,42 @@
typedef GrSurface INHERITED;
};
+/**
+ * Represents a texture that is intended to be accessed in device coords with an offset.
+ */
+class GrDeviceCoordTexture {
+public:
+ GrDeviceCoordTexture() { fOffset.set(0, 0); }
+
+ GrDeviceCoordTexture(const GrDeviceCoordTexture& other) {
+ *this = other;
+ }
+
+ GrDeviceCoordTexture(GrTexture* texture, const SkIPoint& offset)
+ : fTexture(SkSafeRef(texture))
+ , fOffset(offset) {
+ }
+
+ GrDeviceCoordTexture& operator=(const GrDeviceCoordTexture& other) {
+ fTexture.reset(SkSafeRef(other.fTexture.get()));
+ fOffset = other.fOffset;
+ return *this;
+ }
+
+ const SkIPoint& offset() const { return fOffset; }
+
+ void setOffset(const SkIPoint& offset) { fOffset = offset; }
+ void setOffset(int ox, int oy) { fOffset.set(ox, oy); }
+
+ GrTexture* texture() const { return fTexture.get(); }
+
+ GrTexture* setTexture(GrTexture* texture) {
+ fTexture.reset(SkSafeRef(texture));
+ return texture;
+ }
+private:
+ SkAutoTUnref<GrTexture> fTexture;
+ SkIPoint fOffset;
+};
+
#endif