michael@0: #include "GrBicubicEffect.h"
michael@0: 
michael@0: #define DS(x) SkDoubleToScalar(x)
michael@0: 
michael@0: const SkScalar GrBicubicEffect::gMitchellCoefficients[16] = {
michael@0:     DS( 1.0 / 18.0), DS(-9.0 / 18.0), DS( 15.0 / 18.0), DS( -7.0 / 18.0),
michael@0:     DS(16.0 / 18.0), DS( 0.0 / 18.0), DS(-36.0 / 18.0), DS( 21.0 / 18.0),
michael@0:     DS( 1.0 / 18.0), DS( 9.0 / 18.0), DS( 27.0 / 18.0), DS(-21.0 / 18.0),
michael@0:     DS( 0.0 / 18.0), DS( 0.0 / 18.0), DS( -6.0 / 18.0), DS(  7.0 / 18.0),
michael@0: };
michael@0: 
michael@0: 
michael@0: class GrGLBicubicEffect : public GrGLEffect {
michael@0: public:
michael@0:     GrGLBicubicEffect(const GrBackendEffectFactory& factory,
michael@0:                       const GrDrawEffect&);
michael@0: 
michael@0:     virtual void emitCode(GrGLShaderBuilder*,
michael@0:                           const GrDrawEffect&,
michael@0:                           EffectKey,
michael@0:                           const char* outputColor,
michael@0:                           const char* inputColor,
michael@0:                           const TransformedCoordsArray&,
michael@0:                           const TextureSamplerArray&) SK_OVERRIDE;
michael@0: 
michael@0:     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
michael@0: 
michael@0:     static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
michael@0:         const GrTextureDomain& domain = drawEffect.castEffect<GrBicubicEffect>().domain();
michael@0:         return GrTextureDomain::GLDomain::DomainKey(domain);
michael@0:     }
michael@0: 
michael@0: private:
michael@0:     typedef GrGLUniformManager::UniformHandle        UniformHandle;
michael@0: 
michael@0:     UniformHandle               fCoefficientsUni;
michael@0:     UniformHandle               fImageIncrementUni;
michael@0:     GrTextureDomain::GLDomain   fDomain;
michael@0: 
michael@0:     typedef GrGLEffect INHERITED;
michael@0: };
michael@0: 
michael@0: GrGLBicubicEffect::GrGLBicubicEffect(const GrBackendEffectFactory& factory, const GrDrawEffect&)
michael@0:     : INHERITED(factory) {
michael@0: }
michael@0: 
michael@0: void GrGLBicubicEffect::emitCode(GrGLShaderBuilder* builder,
michael@0:                                  const GrDrawEffect& drawEffect,
michael@0:                                  EffectKey key,
michael@0:                                  const char* outputColor,
michael@0:                                  const char* inputColor,
michael@0:                                  const TransformedCoordsArray& coords,
michael@0:                                  const TextureSamplerArray& samplers) {
michael@0:     const GrTextureDomain& domain = drawEffect.castEffect<GrBicubicEffect>().domain();
michael@0: 
michael@0:     SkString coords2D = builder->ensureFSCoords2D(coords, 0);
michael@0:     fCoefficientsUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
michael@0:                                            kMat44f_GrSLType, "Coefficients");
michael@0:     fImageIncrementUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
michael@0:                                              kVec2f_GrSLType, "ImageIncrement");
michael@0: 
michael@0:     const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
michael@0:     const char* coeff = builder->getUniformCStr(fCoefficientsUni);
michael@0: 
michael@0:     SkString cubicBlendName;
michael@0: 
michael@0:     static const GrGLShaderVar gCubicBlendArgs[] = {
michael@0:         GrGLShaderVar("coefficients",  kMat44f_GrSLType),
michael@0:         GrGLShaderVar("t",             kFloat_GrSLType),
michael@0:         GrGLShaderVar("c0",            kVec4f_GrSLType),
michael@0:         GrGLShaderVar("c1",            kVec4f_GrSLType),
michael@0:         GrGLShaderVar("c2",            kVec4f_GrSLType),
michael@0:         GrGLShaderVar("c3",            kVec4f_GrSLType),
michael@0:     };
michael@0:     builder->fsEmitFunction(kVec4f_GrSLType,
michael@0:                             "cubicBlend",
michael@0:                             SK_ARRAY_COUNT(gCubicBlendArgs),
michael@0:                             gCubicBlendArgs,
michael@0:                             "\tvec4 ts = vec4(1.0, t, t * t, t * t * t);\n"
michael@0:                             "\tvec4 c = coefficients * ts;\n"
michael@0:                             "\treturn c.x * c0 + c.y * c1 + c.z * c2 + c.w * c3;\n",
michael@0:                             &cubicBlendName);
michael@0:     builder->fsCodeAppendf("\tvec2 coord = %s - %s * vec2(0.5);\n", coords2D.c_str(), imgInc);
michael@0:     // We unnormalize the coord in order to determine our fractional offset (f) within the texel
michael@0:     // We then snap coord to a texel center and renormalize. The snap prevents cases where the
michael@0:     // starting coords are near a texel boundary and accumulations of imgInc would cause us to skip/
michael@0:     // double hit a texel.
michael@0:     builder->fsCodeAppendf("\tcoord /= %s;\n", imgInc);
michael@0:     builder->fsCodeAppend("\tvec2 f = fract(coord);\n");
michael@0:     builder->fsCodeAppendf("\tcoord = (coord - f + vec2(0.5)) * %s;\n", imgInc);
michael@0:     builder->fsCodeAppend("\tvec4 rowColors[4];\n");
michael@0:     for (int y = 0; y < 4; ++y) {
michael@0:         for (int x = 0; x < 4; ++x) {
michael@0:             SkString coord;
michael@0:             coord.printf("coord + %s * vec2(%d, %d)", imgInc, x - 1, y - 1);
michael@0:             SkString sampleVar;
michael@0:             sampleVar.printf("rowColors[%d]", x);
michael@0:             fDomain.sampleTexture(builder, domain, sampleVar.c_str(), coord, samplers[0]);
michael@0:         }
michael@0:         builder->fsCodeAppendf("\tvec4 s%d = %s(%s, f.x, rowColors[0], rowColors[1], rowColors[2], rowColors[3]);\n", y, cubicBlendName.c_str(), coeff);
michael@0:     }
michael@0:     SkString bicubicColor;
michael@0:     bicubicColor.printf("%s(%s, f.y, s0, s1, s2, s3)", cubicBlendName.c_str(), coeff);
michael@0:     builder->fsCodeAppendf("\t%s = %s;\n", outputColor, (GrGLSLExpr4(bicubicColor.c_str()) * GrGLSLExpr4(inputColor)).c_str());
michael@0: }
michael@0: 
michael@0: void GrGLBicubicEffect::setData(const GrGLUniformManager& uman,
michael@0:                                 const GrDrawEffect& drawEffect) {
michael@0:     const GrBicubicEffect& effect = drawEffect.castEffect<GrBicubicEffect>();
michael@0:     const GrTexture& texture = *effect.texture(0);
michael@0:     float imageIncrement[2];
michael@0:     imageIncrement[0] = 1.0f / texture.width();
michael@0:     imageIncrement[1] = 1.0f / texture.height();
michael@0:     uman.set2fv(fImageIncrementUni, 1, imageIncrement);
michael@0:     uman.setMatrix4f(fCoefficientsUni, effect.coefficients());
michael@0:     fDomain.setData(uman, effect.domain(), texture.origin());
michael@0: }
michael@0: 
michael@0: static inline void convert_row_major_scalar_coeffs_to_column_major_floats(float dst[16],
michael@0:                                                                           const SkScalar src[16]) {
michael@0:     for (int y = 0; y < 4; y++) {
michael@0:         for (int x = 0; x < 4; x++) {
michael@0:             dst[x * 4 + y] = SkScalarToFloat(src[y * 4 + x]);
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: GrBicubicEffect::GrBicubicEffect(GrTexture* texture,
michael@0:                                  const SkScalar coefficients[16],
michael@0:                                  const SkMatrix &matrix,
michael@0:                                  const SkShader::TileMode tileModes[2])
michael@0:   : INHERITED(texture, matrix, GrTextureParams(tileModes, GrTextureParams::kNone_FilterMode))
michael@0:   , fDomain(GrTextureDomain::IgnoredDomain()) {
michael@0:     convert_row_major_scalar_coeffs_to_column_major_floats(fCoefficients, coefficients);
michael@0: }
michael@0: 
michael@0: GrBicubicEffect::GrBicubicEffect(GrTexture* texture,
michael@0:                                  const SkScalar coefficients[16],
michael@0:                                  const SkMatrix &matrix,
michael@0:                                  const SkRect& domain)
michael@0:   : INHERITED(texture, matrix, GrTextureParams(SkShader::kClamp_TileMode,
michael@0:                                                GrTextureParams::kNone_FilterMode))
michael@0:   , fDomain(domain, GrTextureDomain::kClamp_Mode) {
michael@0:     convert_row_major_scalar_coeffs_to_column_major_floats(fCoefficients, coefficients);
michael@0: }
michael@0: 
michael@0: GrBicubicEffect::~GrBicubicEffect() {
michael@0: }
michael@0: 
michael@0: const GrBackendEffectFactory& GrBicubicEffect::getFactory() const {
michael@0:     return GrTBackendEffectFactory<GrBicubicEffect>::getInstance();
michael@0: }
michael@0: 
michael@0: bool GrBicubicEffect::onIsEqual(const GrEffect& sBase) const {
michael@0:     const GrBicubicEffect& s = CastEffect<GrBicubicEffect>(sBase);
michael@0:     return this->textureAccess(0) == s.textureAccess(0) &&
michael@0:            !memcmp(fCoefficients, s.coefficients(), 16);
michael@0: }
michael@0: 
michael@0: void GrBicubicEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
michael@0:     // FIXME: Perhaps we can do better.
michael@0:     *validFlags = 0;
michael@0:     return;
michael@0: }
michael@0: 
michael@0: GR_DEFINE_EFFECT_TEST(GrBicubicEffect);
michael@0: 
michael@0: GrEffectRef* GrBicubicEffect::TestCreate(SkRandom* random,
michael@0:                                          GrContext* context,
michael@0:                                          const GrDrawTargetCaps&,
michael@0:                                          GrTexture* textures[]) {
michael@0:     int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
michael@0:                                       GrEffectUnitTest::kAlphaTextureIdx;
michael@0:     SkScalar coefficients[16];
michael@0:     for (int i = 0; i < 16; i++) {
michael@0:         coefficients[i] = random->nextSScalar1();
michael@0:     }
michael@0:     return GrBicubicEffect::Create(textures[texIdx], coefficients);
michael@0: }