Create fragment processor for performing input color blend with child processor

The new FP is used to implement SkXM::Mode color filters and SkXM::Mode image filters. Also, these now support all advanced SkXM::Mode xfermodes.

Review URL: https://codereview.chromium.org/1334293003

2 files changed, 12 insertions, 9 deletions

diff --git a/include/gpu/effects/GrCustomXfermode.h b/include/gpu/effects/GrCustomXfermode.h
index 557397077e..bcbd5833ca 100644
--- a/include/gpu/effects/GrCustomXfermode.h
+++ b/include/gpu/effects/GrCustomXfermode.h
@@ -10,21 +10,14 @@
 
 #include "SkXfermode.h"
 
-class GrFragmentProcessor;
 class GrTexture;
 
 /**
  * Custom Xfer modes are used for blending when the blend mode cannot be represented using blend
- * coefficients. It is assumed that all blending is done within the processors' emit code. For each
- * blend mode there should be a matching fragment processor (used when blending with a background
- * texture) and xfer processor.
+ * coefficients.
  */
 namespace GrCustomXfermode {
-    bool IsSupportedMode(SkXfermode::Mode mode); 
-
-    GrFragmentProcessor* CreateFP(GrProcessorDataManager*, SkXfermode::Mode mode,
-                                  GrTexture* background);
-
+    bool IsSupportedMode(SkXfermode::Mode mode);
     GrXPFactory* CreateXPFactory(SkXfermode::Mode mode);
 };
 
diff --git a/include/gpu/effects/GrXfermodeFragmentProcessor.h b/include/gpu/effects/GrXfermodeFragmentProcessor.h
index d93b400b8b..e2d1c0a544 100644
--- a/include/gpu/effects/GrXfermodeFragmentProcessor.h
+++ b/include/gpu/effects/GrXfermodeFragmentProcessor.h
@@ -13,6 +13,16 @@
 class GrFragmentProcessor;
 
 namespace GrXfermodeFragmentProcessor {
+    /** The color input to the returned processor is treated as the src and the passed in processor
+        is the dst. */
+    const GrFragmentProcessor* CreateFromDstProcessor(const GrFragmentProcessor* dst,
+                                                      SkXfermode::Mode mode);
+
+    /** The color input to the returned processor is treated as the dst and the passed in processor
+        is the src. */
+    const GrFragmentProcessor* CreateFromSrcProcessor(const GrFragmentProcessor* src,
+                                                      SkXfermode::Mode mode);
+
     const GrFragmentProcessor* CreateFromTwoProcessors(const GrFragmentProcessor* src,
                                                        const GrFragmentProcessor* dst,
                                                        SkXfermode::Mode mode);