Split AlphaThresholdEffect out into its own file

src/effects/GrAlphaThresholdFragmentProcessor.cpp

Index: src/effects/GrAlphaThresholdFragmentProcessor.cpp
diff --git a/src/effects/GrAlphaThresholdFragmentProcessor.cpp b/src/effects/GrAlphaThresholdFragmentProcessor.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..b1632abed03b77cadf7c5acbd3698fe6acaa6bf0
--- /dev/null
+++ b/src/effects/GrAlphaThresholdFragmentProcessor.cpp
@@ -0,0 +1,175 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrAlphaThresholdFragmentProcessor.h"
+
+#if SK_SUPPORT_GPU
+
+#include "GrInvariantOutput.h"
+#include "GrTextureAccess.h"
+
+#include "glsl/GrGLSLFragmentProcessor.h"
+#include "glsl/GrGLSLFragmentShaderBuilder.h"
+#include "glsl/GrGLSLUniformHandler.h"
+
+sk_sp<GrFragmentProcessor> GrAlphaThresholdFragmentProcessor::Make(GrTexture* texture,
+                                                                   GrTexture* maskTexture,
+                                                                   float innerThreshold,
+                                                                   float outerThreshold,
+                                                                   const SkIRect& bounds) {
+    return sk_sp<GrFragmentProcessor>(new GrAlphaThresholdFragmentProcessor(
+                                                    texture, maskTexture,
+                                                    innerThreshold, outerThreshold,
+                                                    bounds));
+}
+
+static SkMatrix make_div_and_translate_matrix(GrTexture* texture, int x, int y) {
+    SkMatrix matrix = GrCoordTransform::MakeDivByTextureWHMatrix(texture);
+    matrix.preTranslate(SkIntToScalar(x), SkIntToScalar(y));
+    return matrix;
+}
+
+GrAlphaThresholdFragmentProcessor::GrAlphaThresholdFragmentProcessor(GrTexture* texture,
+                                                                     GrTexture* maskTexture,
+                                                                     float innerThreshold,
+                                                                     float outerThreshold,
+                                                                     const SkIRect& bounds)
+    : fInnerThreshold(innerThreshold)
+    , fOuterThreshold(outerThreshold)
+    , fImageCoordTransform(kLocal_GrCoordSet,
+                           GrCoordTransform::MakeDivByTextureWHMatrix(texture), texture,
+                           GrTextureParams::kNone_FilterMode)
+    , fImageTextureAccess(texture)
+    , fMaskCoordTransform(kLocal_GrCoordSet,
+                          make_div_and_translate_matrix(maskTexture, -bounds.x(), -bounds.y()),
+                          maskTexture,
+                          GrTextureParams::kNone_FilterMode)
+    , fMaskTextureAccess(maskTexture) {
+    this->initClassID<GrAlphaThresholdFragmentProcessor>();
+    this->addCoordTransform(&fImageCoordTransform);
+    this->addTextureAccess(&fImageTextureAccess);
+    this->addCoordTransform(&fMaskCoordTransform);
+    this->addTextureAccess(&fMaskTextureAccess);
+}
+
+bool GrAlphaThresholdFragmentProcessor::onIsEqual(const GrFragmentProcessor& sBase) const {
+    const GrAlphaThresholdFragmentProcessor& s = sBase.cast<GrAlphaThresholdFragmentProcessor>();
+    return (this->fInnerThreshold == s.fInnerThreshold &&
+            this->fOuterThreshold == s.fOuterThreshold);
+}
+
+void GrAlphaThresholdFragmentProcessor::onComputeInvariantOutput(GrInvariantOutput* inout) const {
+    if (GrPixelConfigIsAlphaOnly(this->texture(0)->config())) {
+        inout->mulByUnknownSingleComponent();
+    } else if (GrPixelConfigIsOpaque(this->texture(0)->config()) && fOuterThreshold >= 1.f) {
+        inout->mulByUnknownOpaqueFourComponents();
+    } else {
+        inout->mulByUnknownFourComponents();
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+class GrGLAlphaThresholdFragmentProcessor : public GrGLSLFragmentProcessor {
+public:
+    void emitCode(EmitArgs&) override;
+
+protected:
+    void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;
+
+private:
+    GrGLSLProgramDataManager::UniformHandle fInnerThresholdVar;
+    GrGLSLProgramDataManager::UniformHandle fOuterThresholdVar;
+
+    typedef GrGLSLFragmentProcessor INHERITED;
+};
+
+void GrGLAlphaThresholdFragmentProcessor::emitCode(EmitArgs& args) {
+    GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
+    fInnerThresholdVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
+                                                    kFloat_GrSLType, kDefault_GrSLPrecision,
+                                                    "inner_threshold");
+    fOuterThresholdVar = uniformHandler->addUniform(kFragment_GrShaderFlag,
+                                                    kFloat_GrSLType, kDefault_GrSLPrecision,
+                                                    "outer_threshold");
+
+    GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
+    SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 0);
+    SkString maskCoords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 1);
+
+    fragBuilder->codeAppendf("vec2 coord = %s;", coords2D.c_str());
+    fragBuilder->codeAppendf("vec2 mask_coord = %s;", maskCoords2D.c_str());
+    fragBuilder->codeAppend("vec4 input_color = ");
+    fragBuilder->appendTextureLookup(args.fTexSamplers[0], "coord");
+    fragBuilder->codeAppend(";");
+    fragBuilder->codeAppend("vec4 mask_color = ");
+    fragBuilder->appendTextureLookup(args.fTexSamplers[1], "mask_coord");
+    fragBuilder->codeAppend(";");
+
+    fragBuilder->codeAppendf("float inner_thresh = %s;",
+                             uniformHandler->getUniformCStr(fInnerThresholdVar));
+    fragBuilder->codeAppendf("float outer_thresh = %s;",
+                             uniformHandler->getUniformCStr(fOuterThresholdVar));
+    fragBuilder->codeAppend("float mask = mask_color.a;");
+
+    fragBuilder->codeAppend("vec4 color = input_color;");
+    fragBuilder->codeAppend("if (mask < 0.5) {"
+                            "if (color.a > outer_thresh) {"
+                            "float scale = outer_thresh / color.a;"
+                            "color.rgb *= scale;"
+                            "color.a = outer_thresh;"
+                            "}"
+                            "} else if (color.a < inner_thresh) {"
+                            "float scale = inner_thresh / max(0.001, color.a);"
+                            "color.rgb *= scale;"
+                            "color.a = inner_thresh;"
+                            "}");
+
+    fragBuilder->codeAppendf("%s = %s;", args.fOutputColor,
+                             (GrGLSLExpr4(args.fInputColor) * GrGLSLExpr4("color")).c_str());
+}
+
+void GrGLAlphaThresholdFragmentProcessor::onSetData(const GrGLSLProgramDataManager& pdman,
+                                                    const GrProcessor& proc) {
+    const GrAlphaThresholdFragmentProcessor& atfp = proc.cast<GrAlphaThresholdFragmentProcessor>();
+    pdman.set1f(fInnerThresholdVar, atfp.innerThreshold());
+    pdman.set1f(fOuterThresholdVar, atfp.outerThreshold());
+}
+
+/////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrAlphaThresholdFragmentProcessor);
+
+const GrFragmentProcessor* GrAlphaThresholdFragmentProcessor::TestCreate(GrProcessorTestData* d) {
+    GrTexture* bmpTex = d->fTextures[GrProcessorUnitTest::kSkiaPMTextureIdx];
+    GrTexture* maskTex = d->fTextures[GrProcessorUnitTest::kAlphaTextureIdx];
+    float innerThresh = d->fRandom->nextUScalar1();
+    float outerThresh = d->fRandom->nextUScalar1();
+    const int kMaxWidth = 1000;
+    const int kMaxHeight = 1000;
+    uint32_t width = d->fRandom->nextULessThan(kMaxWidth);
+    uint32_t height = d->fRandom->nextULessThan(kMaxHeight);
+    uint32_t x = d->fRandom->nextULessThan(kMaxWidth - width);
+    uint32_t y = d->fRandom->nextULessThan(kMaxHeight - height);
+    SkIRect bounds = SkIRect::MakeXYWH(x, y, width, height);
+    return GrAlphaThresholdFragmentProcessor::Make(bmpTex, maskTex,
+                                                   innerThresh, outerThresh,
+                                                   bounds).release();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+void GrAlphaThresholdFragmentProcessor::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
+                                                              GrProcessorKeyBuilder* b) const {
+    GrGLAlphaThresholdFragmentProcessor::GenKey(*this, caps, b);
+}
+
+GrGLSLFragmentProcessor* GrAlphaThresholdFragmentProcessor::onCreateGLSLInstance() const {
+    return new GrGLAlphaThresholdFragmentProcessor;
+}
+
+#endif