Add GrGradientEffects files. These implementations will be invoked from
GrGLPrograms in a further change, replacing the current CoordMapping
enums.
http://codereview.appspot.com/6250081/
git-svn-id: http://skia.googlecode.com/svn/trunk@4104 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/effects/GrGradientEffects.cpp b/src/gpu/effects/GrGradientEffects.cpp
new file mode 100644
index 0000000..3f498b3
--- /dev/null
+++ b/src/gpu/effects/GrGradientEffects.cpp
@@ -0,0 +1,365 @@
+/*
+ * 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 "GrGradientEffects.h"
+#include "gl/GrGLProgramStage.h"
+#include "GrProgramStageFactory.h"
+
+/////////////////////////////////////////////////////////////////////
+
+class GrGLRadialGradient : public GrGLProgramStage {
+
+public:
+
+ GrGLRadialGradient(const GrProgramStageFactory& factory,
+ const GrCustomStage&) : INHERITED (factory) { }
+ virtual ~GrGLRadialGradient() { }
+
+ virtual void emitVS(GrGLShaderBuilder* state,
+ const char* vertexCoords) SK_OVERRIDE { }
+ virtual void emitFS(GrGLShaderBuilder* state,
+ const char* outputColor,
+ const char* inputColor,
+ const char* samplerName) SK_OVERRIDE;
+
+ static StageKey GenKey(const GrCustomStage& s) { return 0; }
+
+private:
+
+ typedef GrGLProgramStage INHERITED;
+
+};
+
+void GrGLRadialGradient::emitFS(GrGLShaderBuilder* state,
+ const char* outputColor,
+ const char* inputColor,
+ const char* samplerName) {
+ state->fSampleCoords.printf("vec2(length(%s.xy), 0.5)",
+ state->fSampleCoords.c_str());
+ state->fComplexCoord = true;
+
+ state->emitDefaultFetch(outputColor, samplerName);
+}
+
+
+/////////////////////////////////////////////////////////////////////
+
+
+GrRadialGradient::GrRadialGradient() {
+
+}
+
+GrRadialGradient::~GrRadialGradient() {
+
+}
+
+
+const GrProgramStageFactory& GrRadialGradient::getFactory() const {
+ return GrTProgramStageFactory<GrRadialGradient>::getInstance();
+}
+
+bool GrRadialGradient::isEqual(const GrCustomStage& sBase) const {
+ return true;
+}
+
+/////////////////////////////////////////////////////////////////////
+
+class GrGLRadial2Gradient : public GrGLProgramStage {
+
+public:
+
+ GrGLRadial2Gradient(const GrProgramStageFactory& factory,
+ const GrCustomStage&);
+ virtual ~GrGLRadial2Gradient() { }
+
+ virtual void setupVariables(GrGLShaderBuilder* state,
+ int stage) SK_OVERRIDE;
+ virtual void emitVS(GrGLShaderBuilder* state,
+ const char* vertexCoords) SK_OVERRIDE;
+ virtual void emitFS(GrGLShaderBuilder* state,
+ const char* outputColor,
+ const char* inputColor,
+ const char* samplerName) SK_OVERRIDE;
+ virtual void initUniforms(const GrGLInterface*, int programID) SK_OVERRIDE;
+ virtual void setData(const GrGLInterface*,
+ const GrGLTexture&,
+ GrCustomStage*,
+ int stageNum) SK_OVERRIDE;
+
+ static StageKey GenKey(const GrCustomStage& s) {
+ return (static_cast<const GrRadial2Gradient&>(s).isDegenerate());
+ }
+
+protected:
+
+ const GrGLShaderVar* fParamVar;
+ GrGLint fParamLocation;
+
+ const char* fVSVaryingName;
+ const char* fFSVaryingName;
+
+ bool fIsDegenerate;
+
+ // @{
+ /// Values last uploaded as uniforms
+
+ GrScalar fCachedCenter;
+ GrScalar fCachedRadius;
+ SkBool8 fCachedPosRoot;
+
+ // @}
+
+private:
+
+ typedef GrGLProgramStage INHERITED;
+
+};
+
+GrGLRadial2Gradient::GrGLRadial2Gradient(
+ const GrProgramStageFactory& factory,
+ const GrCustomStage& baseData)
+ : INHERITED(factory)
+ , fParamVar(NULL)
+ , fVSVaryingName(NULL)
+ , fFSVaryingName(NULL)
+ , fCachedCenter(GR_ScalarMax)
+ , fCachedRadius(-GR_ScalarMax)
+ , fCachedPosRoot(0) {
+
+ const GrRadial2Gradient& data =
+ static_cast<const GrRadial2Gradient&>(baseData);
+ fIsDegenerate = data.isDegenerate();
+}
+
+void GrGLRadial2Gradient::setupVariables(GrGLShaderBuilder* state, int stage) {
+ fParamVar = &state->addUniform(
+ GrGLShaderBuilder::kBoth_VariableLifetime,
+ kFloat_GrSLType, "uRadial2Params", stage, 6);
+
+ fParamLocation = GrGLProgramStage::kUseUniform;
+
+ // For radial gradients without perspective we can pass the linear
+ // part of the quadratic as a varying.
+ if (state->fVaryingDims == state->fCoordDims) {
+ state->addVarying(kFloat_GrSLType, "Radial2BCoeff", stage,
+ &fVSVaryingName, &fFSVaryingName);
+ }
+}
+
+void GrGLRadial2Gradient::emitVS(GrGLShaderBuilder* state,
+ const char* vertexCoords) {
+ GrStringBuilder* code = &state->fVSCode;
+ GrStringBuilder p2;
+ GrStringBuilder p3;
+ fParamVar->appendArrayAccess(2, &p2);
+ fParamVar->appendArrayAccess(3, &p3);
+
+ // For radial gradients without perspective we can pass the linear
+ // part of the quadratic as a varying.
+ if (state->fVaryingDims == state->fCoordDims) {
+ // r2Var = 2 * (r2Parm[2] * varCoord.x - r2Param[3])
+ code->appendf("\t%s = 2.0 *(%s * %s.x - %s);\n",
+ fVSVaryingName, p2.c_str(),
+ vertexCoords, p3.c_str());
+ }
+}
+
+void GrGLRadial2Gradient::emitFS(GrGLShaderBuilder* state,
+ const char* outputColor,
+ const char* inputColor,
+ const char* samplerName) {
+ GrStringBuilder* code = &state->fFSCode;
+ GrStringBuilder cName("c");
+ GrStringBuilder ac4Name("ac4");
+ GrStringBuilder rootName("root");
+ GrStringBuilder p0;
+ GrStringBuilder p1;
+ GrStringBuilder p2;
+ GrStringBuilder p3;
+ GrStringBuilder p4;
+ GrStringBuilder p5;
+ fParamVar->appendArrayAccess(0, &p0);
+ fParamVar->appendArrayAccess(1, &p1);
+ fParamVar->appendArrayAccess(2, &p2);
+ fParamVar->appendArrayAccess(3, &p3);
+ fParamVar->appendArrayAccess(4, &p4);
+ fParamVar->appendArrayAccess(5, &p5);
+
+ // If we we're able to interpolate the linear component,
+ // bVar is the varying; otherwise compute it
+ GrStringBuilder bVar;
+ if (state->fCoordDims == state->fVaryingDims) {
+ bVar = fFSVaryingName;
+ GrAssert(2 == state->fVaryingDims);
+ } else {
+ GrAssert(3 == state->fVaryingDims);
+ bVar = "b";
+ //bVar.appendS32(stageNum);
+ code->appendf("\tfloat %s = 2.0 * (%s * %s.x - %s);\n",
+ bVar.c_str(), p2.c_str(),
+ state->fSampleCoords.c_str(), p3.c_str());
+ }
+
+ // c = (x^2)+(y^2) - params[4]
+ code->appendf("\tfloat %s = dot(%s, %s) - %s;\n",
+ cName.c_str(), state->fSampleCoords.c_str(),
+ state->fSampleCoords.c_str(),
+ p4.c_str());
+
+ // If we aren't degenerate, emit some extra code, and accept a slightly
+ // more complex coord.
+ if (fIsDegenerate) {
+
+ // ac4 = 4.0 * params[0] * c
+ code->appendf("\tfloat %s = %s * 4.0 * %s;\n",
+ ac4Name.c_str(), p0.c_str(),
+ cName.c_str());
+
+ // root = sqrt(b^2-4ac)
+ // (abs to avoid exception due to fp precision)
+ code->appendf("\tfloat %s = sqrt(abs(%s*%s - %s));\n",
+ rootName.c_str(), bVar.c_str(), bVar.c_str(),
+ ac4Name.c_str());
+
+ // x coord is: (-b + params[5] * sqrt(b^2-4ac)) * params[1]
+ // y coord is 0.5 (texture is effectively 1D)
+ state->fSampleCoords.printf("vec2((-%s + %s * %s) * %s, 0.5)",
+ bVar.c_str(), p5.c_str(),
+ rootName.c_str(), p1.c_str());
+ } else {
+ // x coord is: -c/b
+ // y coord is 0.5 (texture is effectively 1D)
+ state->fSampleCoords.printf("vec2((-%s / %s), 0.5)",
+ cName.c_str(), bVar.c_str());
+ }
+ state->fComplexCoord = true;
+
+ state->emitDefaultFetch(outputColor, samplerName);
+}
+
+void GrGLRadial2Gradient::initUniforms(const GrGLInterface* gl, int programID) {
+ GR_GL_CALL_RET(gl, fParamLocation,
+ GetUniformLocation(programID, fParamVar->getName().c_str()));
+}
+
+void GrGLRadial2Gradient::setData(const GrGLInterface* gl,
+ const GrGLTexture& texture,
+ GrCustomStage* baseData,
+ int stageNum) {
+ const GrRadial2Gradient* data =
+ static_cast<const GrRadial2Gradient*>(baseData);
+ GrAssert(data->isDegenerate() == fIsDegenerate);
+ GrScalar centerX1 = data->center();
+ GrScalar radius0 = data->radius();
+ if (fCachedCenter != centerX1 ||
+ fCachedRadius != radius0 ||
+ fCachedPosRoot != data->isPosRoot()) {
+
+ GrScalar a = GrMul(centerX1, centerX1) - GR_Scalar1;
+
+ // When we're in the degenerate (linear) case, the second
+ // value will be INF but the program doesn't read it. (We
+ // use the same 6 uniforms even though we don't need them
+ // all in the linear case just to keep the code complexity
+ // down).
+ float values[6] = {
+ GrScalarToFloat(a),
+ 1 / (2.f * GrScalarToFloat(a)),
+ GrScalarToFloat(centerX1),
+ GrScalarToFloat(radius0),
+ GrScalarToFloat(GrMul(radius0, radius0)),
+ data->isPosRoot() ? 1.f : -1.f
+ };
+
+ GR_GL_CALL(gl, Uniform1fv(fParamLocation, 6, values));
+ fCachedCenter = centerX1;
+ fCachedRadius = radius0;
+ fCachedPosRoot = data->isPosRoot();
+ }
+}
+
+
+/////////////////////////////////////////////////////////////////////
+
+GrRadial2Gradient::GrRadial2Gradient(GrScalar center,
+ GrScalar radius,
+ bool posRoot)
+ : fCenterX1 (center)
+ , fRadius0 (radius)
+ , fPosRoot (posRoot) {
+
+}
+
+GrRadial2Gradient::~GrRadial2Gradient() {
+
+}
+
+
+const GrProgramStageFactory& GrRadial2Gradient::getFactory() const {
+ return GrTProgramStageFactory<GrRadial2Gradient>::getInstance();
+}
+
+bool GrRadial2Gradient::isEqual(const GrCustomStage& sBase) const {
+ const GrRadial2Gradient& s = static_cast<const GrRadial2Gradient&>(sBase);
+ return (this->isDegenerate() == s.isDegenerate());
+}
+
+/////////////////////////////////////////////////////////////////////
+
+class GrGLSweepGradient : public GrGLProgramStage {
+
+public:
+
+ GrGLSweepGradient(const GrProgramStageFactory& factory,
+ const GrCustomStage&) : INHERITED (factory) { }
+ virtual ~GrGLSweepGradient() { }
+
+ virtual void emitVS(GrGLShaderBuilder* state,
+ const char* vertexCoords) SK_OVERRIDE { }
+ virtual void emitFS(GrGLShaderBuilder* state,
+ const char* outputColor,
+ const char* inputColor,
+ const char* samplerName) SK_OVERRIDE;
+
+ static StageKey GenKey(const GrCustomStage& s) { return 0; }
+
+private:
+
+ typedef GrGLProgramStage INHERITED;
+
+};
+
+void GrGLSweepGradient::emitFS(GrGLShaderBuilder* state,
+ const char* outputColor,
+ const char* inputColor,
+ const char* samplerName) {
+ state->fSampleCoords.printf(
+ "vec2(atan(- %s.y, - %s.x) * 0.1591549430918 + 0.5, 0.5)",
+ state->fSampleCoords.c_str(), state->fSampleCoords.c_str());
+ state->fComplexCoord = true;
+
+ state->emitDefaultFetch(outputColor, samplerName);
+}
+
+/////////////////////////////////////////////////////////////////////
+
+GrSweepGradient::GrSweepGradient() {
+
+}
+
+GrSweepGradient::~GrSweepGradient() {
+
+}
+
+const GrProgramStageFactory& GrSweepGradient::getFactory() const {
+ return GrTProgramStageFactory<GrSweepGradient>::getInstance();
+}
+
+bool GrSweepGradient::isEqual(const GrCustomStage& sBase) const {
+ return true;
+}
+