Implement approx-match support in image filter saveLayer() offscreen.

src/gpu/effects/GrTextureDomain.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrTextureDomain.h"
 #include "GrInvariantOutput.h"
 #include "GrSimpleTextureEffect.h"
@@ skipping 10 matching lines @@
     } else {
         fMode = mode;
     }
 
     if (fMode != kIgnore_Mode) {
         // We don't currently handle domains that are empty or don't intersect the texture.
         // It is OK if the domain rect is a line or point, but it should not be inverted. We do not
         // handle rects that do not intersect the [0..1]x[0..1] rect.
         SkASSERT(domain.fLeft <= domain.fRight);
         SkASSERT(domain.fTop <= domain.fBottom);
-        fDomain.fLeft = SkMaxScalar(domain.fLeft, kFullRect.fLeft);
-        fDomain.fRight = SkMinScalar(domain.fRight, kFullRect.fRight);
-        fDomain.fTop = SkMaxScalar(domain.fTop, kFullRect.fTop);
-        fDomain.fBottom = SkMinScalar(domain.fBottom, kFullRect.fBottom);
+        fDomain.fLeft = SkScalarPin(domain.fLeft, kFullRect.fLeft, kFullRect.fRight);
+        fDomain.fRight = SkScalarPin(domain.fRight, kFullRect.fLeft, kFullRect.fRight);
+        fDomain.fTop = SkScalarPin(domain.fTop, kFullRect.fTop, kFullRect.fBottom);
+        fDomain.fBottom = SkScalarPin(domain.fBottom, kFullRect.fTop, kFullRect.fBottom);
         SkASSERT(fDomain.fLeft <= fDomain.fRight);
         SkASSERT(fDomain.fTop <= fDomain.fBottom);
     }
 }
 
 //////////////////////////////////////////////////////////////////////////////
 
 void GrTextureDomain::GLDomain::sampleTexture(GrGLShaderBuilder* builder,
                                               const GrTextureDomain& textureDomain,
                                               const char* outColor,
@@ skipping 257 matching lines @@
     const SkMatrix& matrix = GrProcessorUnitTest::TestMatrix(random);
     bool bilerp = mode != GrTextureDomain::kRepeat_Mode ? random->nextBool() : false;
     GrCoordSet coords = random->nextBool() ? kLocal_GrCoordSet : kDevice_GrCoordSet;
     return GrTextureDomainEffect::Create(textures[texIdx],
                                          matrix,
                                          domain,
                                          mode,
                                          bilerp ? GrTextureParams::kBilerp_FilterMode : GrTextureParams::kNone_FilterMode,
                                          coords);
 }