Use GrTextureDomain in GrBicubicEffect to perform non-bleeding HQ filter drawBitmap.

src/gpu/effects/GrBicubicEffect.h

Index: src/gpu/effects/GrBicubicEffect.h
diff --git a/src/gpu/effects/GrBicubicEffect.h b/src/gpu/effects/GrBicubicEffect.h
index 85bec771b4706858439a457f389abb9ddec8c0c1..9101a3c20eff34b111577c1e3d3816d55fde3dcc 100644
--- a/src/gpu/effects/GrBicubicEffect.h
+++ b/src/gpu/effects/GrBicubicEffect.h
@@ -9,6 +9,7 @@
 #define GrBicubicTextureEffect_DEFINED
 
 #include "GrSingleTextureEffect.h"
+#include "GrTextureDomain.h"
 #include "GrDrawEffect.h"
 #include "gl/GrGLEffect.h"
 #include "GrTBackendEffectFactory.h"
@@ -31,46 +32,53 @@ public:
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
 
-    /**
-     * Create a simple Mitchell filter effect.
-     */
-    static GrEffectRef* Create(GrTexture* tex) {
-        return Create(tex, gMitchellCoefficients);
-    }
+    const GrTextureDomain& domain() const { return fDomain; }
 
     /**
-     * Create a simple filter effect with custom bicubic coefficients.
+     * Create a simple filter effect with custom bicubic coefficients and optional domain.
      */
     static GrEffectRef* Create(GrTexture* tex, const SkScalar coefficients[16]) {

[Stephen White, 2013/12/12 01:50:07]

Maybe this variant of the factory function should take a texture domain too, and
default to no domain (and clamp mode) if not specified. (The comment above seems
to suggest it does this, but it doesn't.)

[bsalomon, 2013/12/13 20:53:26]

Done.

-        const SkShader::TileMode tm[] = { SkShader::kClamp_TileMode, SkShader::kClamp_TileMode };
-        return Create(tex, coefficients, MakeDivByTextureWHMatrix(tex), tm);
+        static const SkShader::TileMode kTileModes[] = { SkShader::kClamp_TileMode,
+                                                         SkShader::kClamp_TileMode };
+        return Create(tex, coefficients, MakeDivByTextureWHMatrix(tex), kTileModes);
     }
 
     /**
      * Create a Mitchell filter effect with specified texture matrix and x/y tile modes.
      */
-    static GrEffectRef* Create(GrTexture* tex,
-                               const SkMatrix& matrix,
+    static GrEffectRef* Create(GrTexture* tex, const SkMatrix& matrix,
                                SkShader::TileMode tileModes[2]) {
         return Create(tex, gMitchellCoefficients, matrix, tileModes);
     }
 
     /**
-     * The most general Create method. This allows specification of the bicubic coefficients, the
-     * texture matrix, and the x/y tilemodes.
+     * Create a filter effect with custom bicubic coefficients, the texture matrix, and the x/y
+     * tilemodes.
      */
     static GrEffectRef* Create(GrTexture* tex, const SkScalar coefficients[16],
-                               const SkMatrix& matrix,
-                               const SkShader::TileMode tileModes[2]) {
+                               const SkMatrix& matrix, const SkShader::TileMode tileModes[2]) {
         AutoEffectUnref effect(SkNEW_ARGS(GrBicubicEffect, (tex, coefficients, matrix, tileModes)));
         return CreateEffectRef(effect);
     }
 
+    /**
+     * Create a Mitchell filter effect with a texture matrix and a domain.
+     */
+    static GrEffectRef* Create(GrTexture* tex, const SkMatrix& matrix, const SkRect& domain) {
+        AutoEffectUnref effect(SkNEW_ARGS(GrBicubicEffect, (tex, gMitchellCoefficients, matrix,
+                                                            domain)));
+        return CreateEffectRef(effect);
+    }
+
 private:
     GrBicubicEffect(GrTexture*, const SkScalar coefficients[16],
                     const SkMatrix &matrix, const SkShader::TileMode tileModes[2]);
+    GrBicubicEffect(GrTexture*, const SkScalar coefficients[16],
+                    const SkMatrix &matrix, const SkRect& domain);
     virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
-    float    fCoefficients[16];
+
+    float           fCoefficients[16];
+    GrTextureDomain fDomain;
 
     GR_DECLARE_EFFECT_TEST;