YUV to RGB converter
This is a first piece of the GPU YUV decoder, which is the actual effect that performs the conversion. For now, it simply applies the conversion matrix, since it is all I need. I may add modes if different matrices need to be applied or if I add color profile support here.
I'll try to keep these cls short and easy to review, but there should be a few of them coming once this one is in.
BUG=skia:
R=senorblanco@chromium.org, senorblanco@google.com, reed@google.com, bsalomon@google.com
Author: sugoi@chromium.org
Review URL: https://codereview.chromium.org/378503006
diff --git a/src/gpu/effects/GrYUVtoRGBEffect.cpp b/src/gpu/effects/GrYUVtoRGBEffect.cpp
new file mode 100644
index 0000000..1e3810f
--- /dev/null
+++ b/src/gpu/effects/GrYUVtoRGBEffect.cpp
@@ -0,0 +1,108 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrYUVtoRGBEffect.h"
+
+#include "GrCoordTransform.h"
+#include "GrEffect.h"
+#include "gl/GrGLEffect.h"
+#include "GrTBackendEffectFactory.h"
+
+namespace {
+
+class YUVtoRGBEffect : public GrEffect {
+public:
+ static GrEffectRef* Create(GrTexture* yTexture, GrTexture* uTexture, GrTexture* vTexture) {
+ AutoEffectUnref effect(SkNEW_ARGS(YUVtoRGBEffect, (yTexture, uTexture, vTexture)));
+ return CreateEffectRef(effect);
+ }
+
+ static const char* Name() { return "YUV to RGB"; }
+
+ virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE {
+ return GrTBackendEffectFactory<YUVtoRGBEffect>::getInstance();
+ }
+
+ virtual void getConstantColorComponents(GrColor* color,
+ uint32_t* validFlags) const SK_OVERRIDE {
+ // YUV is opaque
+ *color = 0xFF;
+ *validFlags = kA_GrColorComponentFlag;
+ }
+
+ class GLEffect : public GrGLEffect {
+ public:
+ // this class always generates the same code.
+ static EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&) { return 0; }
+
+ GLEffect(const GrBackendEffectFactory& factory,
+ const GrDrawEffect&)
+ : INHERITED(factory) {
+ }
+
+ virtual void emitCode(GrGLShaderBuilder* builder,
+ const GrDrawEffect&,
+ EffectKey,
+ const char* outputColor,
+ const char* inputColor,
+ const TransformedCoordsArray& coords,
+ const TextureSamplerArray& samplers) SK_OVERRIDE {
+ const char* yuvMatrix = "yuvMatrix";
+ builder->fsCodeAppendf("\tconst mat4 %s = mat4(1.0, 0.0, 1.402, -0.701,\n\t\t\t"
+ "1.0, -0.344, -0.714, 0.529,\n\t\t\t"
+ "1.0, 1.772, 0.0, -0.886,\n\t\t\t"
+ "0.0, 0.0, 0.0, 1.0);\n",
+ yuvMatrix);
+ builder->fsCodeAppendf("\t%s = vec4(\n\t\t", outputColor);
+ builder->fsAppendTextureLookup(samplers[0], coords[0].c_str(), coords[0].type());
+ builder->fsCodeAppend(".r,\n\t\t");
+ builder->fsAppendTextureLookup(samplers[1], coords[0].c_str(), coords[0].type());
+ builder->fsCodeAppend(".r,\n\t\t");
+ builder->fsAppendTextureLookup(samplers[2], coords[0].c_str(), coords[0].type());
+ builder->fsCodeAppendf(".r,\n\t\t1.0) * %s;\n", yuvMatrix);
+ }
+
+ typedef GrGLEffect INHERITED;
+ };
+
+private:
+ YUVtoRGBEffect(GrTexture* yTexture, GrTexture* uTexture, GrTexture* vTexture)
+ : fCoordTransform(kLocal_GrCoordSet, MakeDivByTextureWHMatrix(yTexture), yTexture)
+ , fYAccess(yTexture)
+ , fUAccess(uTexture)
+ , fVAccess(vTexture) {
+ this->addCoordTransform(&fCoordTransform);
+ this->addTextureAccess(&fYAccess);
+ this->addTextureAccess(&fUAccess);
+ this->addTextureAccess(&fVAccess);
+ this->setWillNotUseInputColor();
+ }
+
+ virtual bool onIsEqual(const GrEffect& sBase) const {
+ const YUVtoRGBEffect& s = CastEffect<YUVtoRGBEffect>(sBase);
+ return fYAccess.getTexture() == s.fYAccess.getTexture() &&
+ fUAccess.getTexture() == s.fUAccess.getTexture() &&
+ fVAccess.getTexture() == s.fVAccess.getTexture();
+ }
+
+ GrCoordTransform fCoordTransform;
+ GrTextureAccess fYAccess;
+ GrTextureAccess fUAccess;
+ GrTextureAccess fVAccess;
+
+ typedef GrEffect INHERITED;
+};
+
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+GrEffectRef* GrYUVtoRGBEffect::Create(GrTexture* yTexture,
+ GrTexture* uTexture,
+ GrTexture* vTexture) {
+ return YUVtoRGBEffect::Create(yTexture, uTexture, vTexture);
+}