| /* |
| * Copyright 2015 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "effects/GrCustomXfermode.h" |
| #include "effects/GrCustomXfermodePriv.h" |
| |
| #include "GrCoordTransform.h" |
| #include "GrContext.h" |
| #include "GrFragmentProcessor.h" |
| #include "GrInvariantOutput.h" |
| #include "GrProcessor.h" |
| #include "GrTexture.h" |
| #include "GrTextureAccess.h" |
| #include "SkXfermode.h" |
| #include "gl/GrGLCaps.h" |
| #include "gl/GrGLGpu.h" |
| #include "gl/GrGLProcessor.h" |
| #include "gl/GrGLProgramDataManager.h" |
| #include "gl/builders/GrGLProgramBuilder.h" |
| |
| bool GrCustomXfermode::IsSupportedMode(SkXfermode::Mode mode) { |
| return mode > SkXfermode::kLastCoeffMode && mode <= SkXfermode::kLastMode; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Static helpers |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| static GrBlendEquation hw_blend_equation(SkXfermode::Mode mode) { |
| enum { kOffset = kOverlay_GrBlendEquation - SkXfermode::kOverlay_Mode }; |
| return static_cast<GrBlendEquation>(mode + kOffset); |
| |
| GR_STATIC_ASSERT(kOverlay_GrBlendEquation == SkXfermode::kOverlay_Mode + kOffset); |
| GR_STATIC_ASSERT(kDarken_GrBlendEquation == SkXfermode::kDarken_Mode + kOffset); |
| GR_STATIC_ASSERT(kLighten_GrBlendEquation == SkXfermode::kLighten_Mode + kOffset); |
| GR_STATIC_ASSERT(kColorDodge_GrBlendEquation == SkXfermode::kColorDodge_Mode + kOffset); |
| GR_STATIC_ASSERT(kColorBurn_GrBlendEquation == SkXfermode::kColorBurn_Mode + kOffset); |
| GR_STATIC_ASSERT(kHardLight_GrBlendEquation == SkXfermode::kHardLight_Mode + kOffset); |
| GR_STATIC_ASSERT(kSoftLight_GrBlendEquation == SkXfermode::kSoftLight_Mode + kOffset); |
| GR_STATIC_ASSERT(kDifference_GrBlendEquation == SkXfermode::kDifference_Mode + kOffset); |
| GR_STATIC_ASSERT(kExclusion_GrBlendEquation == SkXfermode::kExclusion_Mode + kOffset); |
| GR_STATIC_ASSERT(kMultiply_GrBlendEquation == SkXfermode::kMultiply_Mode + kOffset); |
| GR_STATIC_ASSERT(kHSLHue_GrBlendEquation == SkXfermode::kHue_Mode + kOffset); |
| GR_STATIC_ASSERT(kHSLSaturation_GrBlendEquation == SkXfermode::kSaturation_Mode + kOffset); |
| GR_STATIC_ASSERT(kHSLColor_GrBlendEquation == SkXfermode::kColor_Mode + kOffset); |
| GR_STATIC_ASSERT(kHSLLuminosity_GrBlendEquation == SkXfermode::kLuminosity_Mode + kOffset); |
| GR_STATIC_ASSERT(kGrBlendEquationCnt == SkXfermode::kLastMode + 1 + kOffset); |
| } |
| |
| static void hard_light(GrGLFragmentBuilder* fsBuilder, |
| const char* final, |
| const char* src, |
| const char* dst) { |
| static const char kComponents[] = {'r', 'g', 'b'}; |
| for (size_t i = 0; i < SK_ARRAY_COUNT(kComponents); ++i) { |
| char component = kComponents[i]; |
| fsBuilder->codeAppendf("if (2.0 * %s.%c <= %s.a) {", src, component, src); |
| fsBuilder->codeAppendf("%s.%c = 2.0 * %s.%c * %s.%c;", |
| final, component, src, component, dst, component); |
| fsBuilder->codeAppend("} else {"); |
| fsBuilder->codeAppendf("%s.%c = %s.a * %s.a - 2.0 * (%s.a - %s.%c) * (%s.a - %s.%c);", |
| final, component, src, dst, dst, dst, component, src, src, |
| component); |
| fsBuilder->codeAppend("}"); |
| } |
| fsBuilder->codeAppendf("%s.rgb += %s.rgb * (1.0 - %s.a) + %s.rgb * (1.0 - %s.a);", |
| final, src, dst, dst, src); |
| } |
| |
| // Does one component of color-dodge |
| static void color_dodge_component(GrGLFragmentBuilder* fsBuilder, |
| const char* final, |
| const char* src, |
| const char* dst, |
| const char component) { |
| fsBuilder->codeAppendf("if (0.0 == %s.%c) {", dst, component); |
| fsBuilder->codeAppendf("%s.%c = %s.%c * (1.0 - %s.a);", |
| final, component, src, component, dst); |
| fsBuilder->codeAppend("} else {"); |
| fsBuilder->codeAppendf("float d = %s.a - %s.%c;", src, src, component); |
| fsBuilder->codeAppend("if (0.0 == d) {"); |
| fsBuilder->codeAppendf("%s.%c = %s.a * %s.a + %s.%c * (1.0 - %s.a) + %s.%c * (1.0 - %s.a);", |
| final, component, src, dst, src, component, dst, dst, component, |
| src); |
| fsBuilder->codeAppend("} else {"); |
| fsBuilder->codeAppendf("d = min(%s.a, %s.%c * %s.a / d);", |
| dst, dst, component, src); |
| fsBuilder->codeAppendf("%s.%c = d * %s.a + %s.%c * (1.0 - %s.a) + %s.%c * (1.0 - %s.a);", |
| final, component, src, src, component, dst, dst, component, src); |
| fsBuilder->codeAppend("}"); |
| fsBuilder->codeAppend("}"); |
| } |
| |
| // Does one component of color-burn |
| static void color_burn_component(GrGLFragmentBuilder* fsBuilder, |
| const char* final, |
| const char* src, |
| const char* dst, |
| const char component) { |
| fsBuilder->codeAppendf("if (%s.a == %s.%c) {", dst, dst, component); |
| fsBuilder->codeAppendf("%s.%c = %s.a * %s.a + %s.%c * (1.0 - %s.a) + %s.%c * (1.0 - %s.a);", |
| final, component, src, dst, src, component, dst, dst, component, |
| src); |
| fsBuilder->codeAppendf("} else if (0.0 == %s.%c) {", src, component); |
| fsBuilder->codeAppendf("%s.%c = %s.%c * (1.0 - %s.a);", |
| final, component, dst, component, src); |
| fsBuilder->codeAppend("} else {"); |
| fsBuilder->codeAppendf("float d = max(0.0, %s.a - (%s.a - %s.%c) * %s.a / %s.%c);", |
| dst, dst, dst, component, src, src, component); |
| fsBuilder->codeAppendf("%s.%c = %s.a * d + %s.%c * (1.0 - %s.a) + %s.%c * (1.0 - %s.a);", |
| final, component, src, src, component, dst, dst, component, src); |
| fsBuilder->codeAppend("}"); |
| } |
| |
| // Does one component of soft-light. Caller should have already checked that dst alpha > 0. |
| static void soft_light_component_pos_dst_alpha(GrGLFragmentBuilder* fsBuilder, |
| const char* final, |
| const char* src, |
| const char* dst, |
| const char component) { |
| // if (2S < Sa) |
| fsBuilder->codeAppendf("if (2.0 * %s.%c <= %s.a) {", src, component, src); |
| // (D^2 (Sa-2 S))/Da+(1-Da) S+D (-Sa+2 S+1) |
| fsBuilder->codeAppendf("%s.%c = (%s.%c*%s.%c*(%s.a - 2.0*%s.%c)) / %s.a +" |
| "(1.0 - %s.a) * %s.%c + %s.%c*(-%s.a + 2.0*%s.%c + 1.0);", |
| final, component, dst, component, dst, component, src, src, |
| component, dst, dst, src, component, dst, component, src, src, |
| component); |
| // else if (4D < Da) |
| fsBuilder->codeAppendf("} else if (4.0 * %s.%c <= %s.a) {", |
| dst, component, dst); |
| fsBuilder->codeAppendf("float DSqd = %s.%c * %s.%c;", |
| dst, component, dst, component); |
| fsBuilder->codeAppendf("float DCub = DSqd * %s.%c;", dst, component); |
| fsBuilder->codeAppendf("float DaSqd = %s.a * %s.a;", dst, dst); |
| fsBuilder->codeAppendf("float DaCub = DaSqd * %s.a;", dst); |
| // (Da^3 (-S)+Da^2 (S-D (3 Sa-6 S-1))+12 Da D^2 (Sa-2 S)-16 D^3 (Sa-2 S))/Da^2 |
| fsBuilder->codeAppendf("%s.%c =" |
| "(-DaCub*%s.%c + DaSqd*(%s.%c - %s.%c * (3.0*%s.a - 6.0*%s.%c - 1.0)) +" |
| " 12.0*%s.a*DSqd*(%s.a - 2.0*%s.%c) - 16.0*DCub * (%s.a - 2.0*%s.%c)) /" |
| "DaSqd;", |
| final, component, src, component, src, component, dst, component, |
| src, src, component, dst, src, src, component, src, src, |
| component); |
| fsBuilder->codeAppendf("} else {"); |
| // -sqrt(Da * D) (Sa-2 S)-Da S+D (Sa-2 S+1)+S |
| fsBuilder->codeAppendf("%s.%c = -sqrt(%s.a*%s.%c)*(%s.a - 2.0*%s.%c) - %s.a*%s.%c +" |
| "%s.%c*(%s.a - 2.0*%s.%c + 1.0) + %s.%c;", |
| final, component, dst, dst, component, src, src, component, dst, |
| src, component, dst, component, src, src, component, src, |
| component); |
| fsBuilder->codeAppendf("}"); |
| } |
| |
| // Adds a function that takes two colors and an alpha as input. It produces a color with the |
| // hue and saturation of the first color, the luminosity of the second color, and the input |
| // alpha. It has this signature: |
| // vec3 set_luminance(vec3 hueSatColor, float alpha, vec3 lumColor). |
| static void add_lum_function(GrGLFragmentBuilder* fsBuilder, SkString* setLumFunction) { |
| // Emit a helper that gets the luminance of a color. |
| SkString getFunction; |
| GrGLShaderVar getLumArgs[] = { |
| GrGLShaderVar("color", kVec3f_GrSLType), |
| }; |
| SkString getLumBody("return dot(vec3(0.3, 0.59, 0.11), color);"); |
| fsBuilder->emitFunction(kFloat_GrSLType, |
| "luminance", |
| SK_ARRAY_COUNT(getLumArgs), getLumArgs, |
| getLumBody.c_str(), |
| &getFunction); |
| |
| // Emit the set luminance function. |
| GrGLShaderVar setLumArgs[] = { |
| GrGLShaderVar("hueSat", kVec3f_GrSLType), |
| GrGLShaderVar("alpha", kFloat_GrSLType), |
| GrGLShaderVar("lumColor", kVec3f_GrSLType), |
| }; |
| SkString setLumBody; |
| setLumBody.printf("float diff = %s(lumColor - hueSat);", getFunction.c_str()); |
| setLumBody.append("vec3 outColor = hueSat + diff;"); |
| setLumBody.appendf("float outLum = %s(outColor);", getFunction.c_str()); |
| setLumBody.append("float minComp = min(min(outColor.r, outColor.g), outColor.b);" |
| "float maxComp = max(max(outColor.r, outColor.g), outColor.b);" |
| "if (minComp < 0.0 && outLum != minComp) {" |
| "outColor = outLum + ((outColor - vec3(outLum, outLum, outLum)) * outLum) /" |
| "(outLum - minComp);" |
| "}" |
| "if (maxComp > alpha && maxComp != outLum) {" |
| "outColor = outLum +" |
| "((outColor - vec3(outLum, outLum, outLum)) * (alpha - outLum)) /" |
| "(maxComp - outLum);" |
| "}" |
| "return outColor;"); |
| fsBuilder->emitFunction(kVec3f_GrSLType, |
| "set_luminance", |
| SK_ARRAY_COUNT(setLumArgs), setLumArgs, |
| setLumBody.c_str(), |
| setLumFunction); |
| } |
| |
| // Adds a function that creates a color with the hue and luminosity of one input color and |
| // the saturation of another color. It will have this signature: |
| // float set_saturation(vec3 hueLumColor, vec3 satColor) |
| static void add_sat_function(GrGLFragmentBuilder* fsBuilder, SkString* setSatFunction) { |
| // Emit a helper that gets the saturation of a color |
| SkString getFunction; |
| GrGLShaderVar getSatArgs[] = { GrGLShaderVar("color", kVec3f_GrSLType) }; |
| SkString getSatBody; |
| getSatBody.printf("return max(max(color.r, color.g), color.b) - " |
| "min(min(color.r, color.g), color.b);"); |
| fsBuilder->emitFunction(kFloat_GrSLType, |
| "saturation", |
| SK_ARRAY_COUNT(getSatArgs), getSatArgs, |
| getSatBody.c_str(), |
| &getFunction); |
| |
| // Emit a helper that sets the saturation given sorted input channels. This used |
| // to use inout params for min, mid, and max components but that seems to cause |
| // problems on PowerVR drivers. So instead it returns a vec3 where r, g ,b are the |
| // adjusted min, mid, and max inputs, respectively. |
| SkString helperFunction; |
| GrGLShaderVar helperArgs[] = { |
| GrGLShaderVar("minComp", kFloat_GrSLType), |
| GrGLShaderVar("midComp", kFloat_GrSLType), |
| GrGLShaderVar("maxComp", kFloat_GrSLType), |
| GrGLShaderVar("sat", kFloat_GrSLType), |
| }; |
| static const char kHelperBody[] = "if (minComp < maxComp) {" |
| "vec3 result;" |
| "result.r = 0.0;" |
| "result.g = sat * (midComp - minComp) / (maxComp - minComp);" |
| "result.b = sat;" |
| "return result;" |
| "} else {" |
| "return vec3(0, 0, 0);" |
| "}"; |
| fsBuilder->emitFunction(kVec3f_GrSLType, |
| "set_saturation_helper", |
| SK_ARRAY_COUNT(helperArgs), helperArgs, |
| kHelperBody, |
| &helperFunction); |
| |
| GrGLShaderVar setSatArgs[] = { |
| GrGLShaderVar("hueLumColor", kVec3f_GrSLType), |
| GrGLShaderVar("satColor", kVec3f_GrSLType), |
| }; |
| const char* helpFunc = helperFunction.c_str(); |
| SkString setSatBody; |
| setSatBody.appendf("float sat = %s(satColor);" |
| "if (hueLumColor.r <= hueLumColor.g) {" |
| "if (hueLumColor.g <= hueLumColor.b) {" |
| "hueLumColor.rgb = %s(hueLumColor.r, hueLumColor.g, hueLumColor.b, sat);" |
| "} else if (hueLumColor.r <= hueLumColor.b) {" |
| "hueLumColor.rbg = %s(hueLumColor.r, hueLumColor.b, hueLumColor.g, sat);" |
| "} else {" |
| "hueLumColor.brg = %s(hueLumColor.b, hueLumColor.r, hueLumColor.g, sat);" |
| "}" |
| "} else if (hueLumColor.r <= hueLumColor.b) {" |
| "hueLumColor.grb = %s(hueLumColor.g, hueLumColor.r, hueLumColor.b, sat);" |
| "} else if (hueLumColor.g <= hueLumColor.b) {" |
| "hueLumColor.gbr = %s(hueLumColor.g, hueLumColor.b, hueLumColor.r, sat);" |
| "} else {" |
| "hueLumColor.bgr = %s(hueLumColor.b, hueLumColor.g, hueLumColor.r, sat);" |
| "}" |
| "return hueLumColor;", |
| getFunction.c_str(), helpFunc, helpFunc, helpFunc, helpFunc, |
| helpFunc, helpFunc); |
| fsBuilder->emitFunction(kVec3f_GrSLType, |
| "set_saturation", |
| SK_ARRAY_COUNT(setSatArgs), setSatArgs, |
| setSatBody.c_str(), |
| setSatFunction); |
| |
| } |
| |
| static void emit_custom_xfermode_code(SkXfermode::Mode mode, |
| GrGLFragmentBuilder* fsBuilder, |
| const char* outputColor, |
| const char* inputColor, |
| const char* dstColor) { |
| // We don't try to optimize for this case at all |
| if (NULL == inputColor) { |
| fsBuilder->codeAppendf("const vec4 ones = vec4(1);"); |
| inputColor = "ones"; |
| } |
| fsBuilder->codeAppendf("// SkXfermode::Mode: %s\n", SkXfermode::ModeName(mode)); |
| |
| // These all perform src-over on the alpha channel. |
| fsBuilder->codeAppendf("%s.a = %s.a + (1.0 - %s.a) * %s.a;", |
| outputColor, inputColor, inputColor, dstColor); |
| |
| switch (mode) { |
| case SkXfermode::kOverlay_Mode: |
| // Overlay is Hard-Light with the src and dst reversed |
| hard_light(fsBuilder, outputColor, dstColor, inputColor); |
| break; |
| case SkXfermode::kDarken_Mode: |
| fsBuilder->codeAppendf("%s.rgb = min((1.0 - %s.a) * %s.rgb + %s.rgb, " |
| "(1.0 - %s.a) * %s.rgb + %s.rgb);", |
| outputColor, |
| inputColor, dstColor, inputColor, |
| dstColor, inputColor, dstColor); |
| break; |
| case SkXfermode::kLighten_Mode: |
| fsBuilder->codeAppendf("%s.rgb = max((1.0 - %s.a) * %s.rgb + %s.rgb, " |
| "(1.0 - %s.a) * %s.rgb + %s.rgb);", |
| outputColor, |
| inputColor, dstColor, inputColor, |
| dstColor, inputColor, dstColor); |
| break; |
| case SkXfermode::kColorDodge_Mode: |
| color_dodge_component(fsBuilder, outputColor, inputColor, dstColor, 'r'); |
| color_dodge_component(fsBuilder, outputColor, inputColor, dstColor, 'g'); |
| color_dodge_component(fsBuilder, outputColor, inputColor, dstColor, 'b'); |
| break; |
| case SkXfermode::kColorBurn_Mode: |
| color_burn_component(fsBuilder, outputColor, inputColor, dstColor, 'r'); |
| color_burn_component(fsBuilder, outputColor, inputColor, dstColor, 'g'); |
| color_burn_component(fsBuilder, outputColor, inputColor, dstColor, 'b'); |
| break; |
| case SkXfermode::kHardLight_Mode: |
| hard_light(fsBuilder, outputColor, inputColor, dstColor); |
| break; |
| case SkXfermode::kSoftLight_Mode: |
| fsBuilder->codeAppendf("if (0.0 == %s.a) {", dstColor); |
| fsBuilder->codeAppendf("%s.rgba = %s;", outputColor, inputColor); |
| fsBuilder->codeAppendf("} else {"); |
| soft_light_component_pos_dst_alpha(fsBuilder, outputColor, inputColor, dstColor, 'r'); |
| soft_light_component_pos_dst_alpha(fsBuilder, outputColor, inputColor, dstColor, 'g'); |
| soft_light_component_pos_dst_alpha(fsBuilder, outputColor, inputColor, dstColor, 'b'); |
| fsBuilder->codeAppendf("}"); |
| break; |
| case SkXfermode::kDifference_Mode: |
| fsBuilder->codeAppendf("%s.rgb = %s.rgb + %s.rgb -" |
| "2.0 * min(%s.rgb * %s.a, %s.rgb * %s.a);", |
| outputColor, inputColor, dstColor, inputColor, dstColor, |
| dstColor, inputColor); |
| break; |
| case SkXfermode::kExclusion_Mode: |
| fsBuilder->codeAppendf("%s.rgb = %s.rgb + %s.rgb - " |
| "2.0 * %s.rgb * %s.rgb;", |
| outputColor, dstColor, inputColor, dstColor, inputColor); |
| break; |
| case SkXfermode::kMultiply_Mode: |
| fsBuilder->codeAppendf("%s.rgb = (1.0 - %s.a) * %s.rgb + " |
| "(1.0 - %s.a) * %s.rgb + " |
| "%s.rgb * %s.rgb;", |
| outputColor, inputColor, dstColor, dstColor, inputColor, |
| inputColor, dstColor); |
| break; |
| case SkXfermode::kHue_Mode: { |
| // SetLum(SetSat(S * Da, Sat(D * Sa)), Sa*Da, D*Sa) + (1 - Sa) * D + (1 - Da) * S |
| SkString setSat, setLum; |
| add_sat_function(fsBuilder, &setSat); |
| add_lum_function(fsBuilder, &setLum); |
| fsBuilder->codeAppendf("vec4 dstSrcAlpha = %s * %s.a;", |
| dstColor, inputColor); |
| fsBuilder->codeAppendf("%s.rgb = %s(%s(%s.rgb * %s.a, dstSrcAlpha.rgb)," |
| "dstSrcAlpha.a, dstSrcAlpha.rgb);", |
| outputColor, setLum.c_str(), setSat.c_str(), inputColor, |
| dstColor); |
| fsBuilder->codeAppendf("%s.rgb += (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb;", |
| outputColor, inputColor, dstColor, dstColor, inputColor); |
| break; |
| } |
| case SkXfermode::kSaturation_Mode: { |
| // SetLum(SetSat(D * Sa, Sat(S * Da)), Sa*Da, D*Sa)) + (1 - Sa) * D + (1 - Da) * S |
| SkString setSat, setLum; |
| add_sat_function(fsBuilder, &setSat); |
| add_lum_function(fsBuilder, &setLum); |
| fsBuilder->codeAppendf("vec4 dstSrcAlpha = %s * %s.a;", |
| dstColor, inputColor); |
| fsBuilder->codeAppendf("%s.rgb = %s(%s(dstSrcAlpha.rgb, %s.rgb * %s.a)," |
| "dstSrcAlpha.a, dstSrcAlpha.rgb);", |
| outputColor, setLum.c_str(), setSat.c_str(), inputColor, |
| dstColor); |
| fsBuilder->codeAppendf("%s.rgb += (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb;", |
| outputColor, inputColor, dstColor, dstColor, inputColor); |
| break; |
| } |
| case SkXfermode::kColor_Mode: { |
| // SetLum(S * Da, Sa* Da, D * Sa) + (1 - Sa) * D + (1 - Da) * S |
| SkString setLum; |
| add_lum_function(fsBuilder, &setLum); |
| fsBuilder->codeAppendf("vec4 srcDstAlpha = %s * %s.a;", |
| inputColor, dstColor); |
| fsBuilder->codeAppendf("%s.rgb = %s(srcDstAlpha.rgb, srcDstAlpha.a, %s.rgb * %s.a);", |
| outputColor, setLum.c_str(), dstColor, inputColor); |
| fsBuilder->codeAppendf("%s.rgb += (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb;", |
| outputColor, inputColor, dstColor, dstColor, inputColor); |
| break; |
| } |
| case SkXfermode::kLuminosity_Mode: { |
| // SetLum(D * Sa, Sa* Da, S * Da) + (1 - Sa) * D + (1 - Da) * S |
| SkString setLum; |
| add_lum_function(fsBuilder, &setLum); |
| fsBuilder->codeAppendf("vec4 srcDstAlpha = %s * %s.a;", |
| inputColor, dstColor); |
| fsBuilder->codeAppendf("%s.rgb = %s(%s.rgb * %s.a, srcDstAlpha.a, srcDstAlpha.rgb);", |
| outputColor, setLum.c_str(), dstColor, inputColor); |
| fsBuilder->codeAppendf("%s.rgb += (1.0 - %s.a) * %s.rgb + (1.0 - %s.a) * %s.rgb;", |
| outputColor, inputColor, dstColor, dstColor, inputColor); |
| break; |
| } |
| default: |
| SkFAIL("Unknown Custom Xfer mode."); |
| break; |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Fragment Processor |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| GrFragmentProcessor* GrCustomXfermode::CreateFP(SkXfermode::Mode mode, GrTexture* background) { |
| if (!GrCustomXfermode::IsSupportedMode(mode)) { |
| return NULL; |
| } else { |
| return SkNEW_ARGS(GrCustomXferFP, (mode, background)); |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| class GLCustomXferFP : public GrGLFragmentProcessor { |
| public: |
| GLCustomXferFP(const GrFragmentProcessor&) {} |
| ~GLCustomXferFP() override {}; |
| |
| void emitCode(GrGLFPBuilder* builder, |
| const GrFragmentProcessor& fp, |
| const char* outputColor, |
| const char* inputColor, |
| const TransformedCoordsArray& coords, |
| const TextureSamplerArray& samplers) override { |
| SkXfermode::Mode mode = fp.cast<GrCustomXferFP>().mode(); |
| GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder(); |
| const char* dstColor = "bgColor"; |
| fsBuilder->codeAppendf("vec4 %s = ", dstColor); |
| fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType()); |
| fsBuilder->codeAppendf(";"); |
| |
| emit_custom_xfermode_code(mode, fsBuilder, outputColor, inputColor, dstColor); |
| } |
| |
| void setData(const GrGLProgramDataManager&, const GrProcessor&) override {} |
| |
| static void GenKey(const GrFragmentProcessor& proc, const GrGLSLCaps&, GrProcessorKeyBuilder* b) { |
| // The background may come from the dst or from a texture. |
| uint32_t key = proc.numTextures(); |
| SkASSERT(key <= 1); |
| key |= proc.cast<GrCustomXferFP>().mode() << 1; |
| b->add32(key); |
| } |
| |
| private: |
| typedef GrGLFragmentProcessor INHERITED; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| GrCustomXferFP::GrCustomXferFP(SkXfermode::Mode mode, GrTexture* background) |
| : fMode(mode) { |
| this->initClassID<GrCustomXferFP>(); |
| |
| SkASSERT(background); |
| fBackgroundTransform.reset(kLocal_GrCoordSet, background, |
| GrTextureParams::kNone_FilterMode); |
| this->addCoordTransform(&fBackgroundTransform); |
| fBackgroundAccess.reset(background); |
| this->addTextureAccess(&fBackgroundAccess); |
| } |
| |
| void GrCustomXferFP::getGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const { |
| GLCustomXferFP::GenKey(*this, caps, b); |
| } |
| |
| GrGLFragmentProcessor* GrCustomXferFP::createGLInstance() const { |
| return SkNEW_ARGS(GLCustomXferFP, (*this)); |
| } |
| |
| bool GrCustomXferFP::onIsEqual(const GrFragmentProcessor& other) const { |
| const GrCustomXferFP& s = other.cast<GrCustomXferFP>(); |
| return fMode == s.fMode; |
| } |
| |
| void GrCustomXferFP::onComputeInvariantOutput(GrInvariantOutput* inout) const { |
| inout->setToUnknown(GrInvariantOutput::kWill_ReadInput); |
| } |
| |
| GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrCustomXferFP); |
| GrFragmentProcessor* GrCustomXferFP::TestCreate(SkRandom* rand, |
| GrContext*, |
| const GrCaps&, |
| GrTexture* textures[]) { |
| int mode = rand->nextRangeU(SkXfermode::kLastCoeffMode + 1, SkXfermode::kLastSeparableMode); |
| |
| return SkNEW_ARGS(GrCustomXferFP, (static_cast<SkXfermode::Mode>(mode), textures[0])); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Xfer Processor |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| class CustomXP : public GrXferProcessor { |
| public: |
| static GrXferProcessor* Create(SkXfermode::Mode mode, const GrDeviceCoordTexture* dstCopy, |
| bool willReadDstColor) { |
| if (!GrCustomXfermode::IsSupportedMode(mode)) { |
| return NULL; |
| } else { |
| return SkNEW_ARGS(CustomXP, (mode, dstCopy, willReadDstColor)); |
| } |
| } |
| |
| ~CustomXP() override {}; |
| |
| const char* name() const override { return "Custom Xfermode"; } |
| |
| GrGLXferProcessor* createGLInstance() const override; |
| |
| bool hasSecondaryOutput() const override { return false; } |
| |
| SkXfermode::Mode mode() const { return fMode; } |
| bool hasHWBlendEquation() const { return -1 != static_cast<int>(fHWBlendEquation); } |
| |
| GrBlendEquation hwBlendEquation() const { |
| SkASSERT(this->hasHWBlendEquation()); |
| return fHWBlendEquation; |
| } |
| |
| private: |
| CustomXP(SkXfermode::Mode mode, const GrDeviceCoordTexture* dstCopy, bool willReadDstColor); |
| |
| GrXferProcessor::OptFlags onGetOptimizations(const GrProcOptInfo& colorPOI, |
| const GrProcOptInfo& coveragePOI, |
| bool doesStencilWrite, |
| GrColor* overrideColor, |
| const GrCaps& caps) override; |
| |
| void onGetGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override; |
| |
| bool onWillNeedXferBarrier(const GrRenderTarget* rt, |
| const GrCaps& caps, |
| GrXferBarrierType* outBarrierType) const override; |
| |
| void onGetBlendInfo(BlendInfo*) const override; |
| |
| bool onIsEqual(const GrXferProcessor& xpBase) const override; |
| |
| SkXfermode::Mode fMode; |
| GrBlendEquation fHWBlendEquation; |
| |
| typedef GrXferProcessor INHERITED; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| GrXPFactory* GrCustomXfermode::CreateXPFactory(SkXfermode::Mode mode) { |
| if (!GrCustomXfermode::IsSupportedMode(mode)) { |
| return NULL; |
| } else { |
| return SkNEW_ARGS(GrCustomXPFactory, (mode)); |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| class GLCustomXP : public GrGLXferProcessor { |
| public: |
| GLCustomXP(const GrXferProcessor&) {} |
| ~GLCustomXP() override {} |
| |
| static void GenKey(const GrXferProcessor& p, const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) { |
| const CustomXP& xp = p.cast<CustomXP>(); |
| uint32_t key = xp.numTextures(); |
| SkASSERT(key <= 1); |
| key |= xp.readsCoverage() << 1; |
| if (xp.hasHWBlendEquation()) { |
| SkASSERT(caps.advBlendEqInteraction() > 0); // 0 will mean !xp.hasHWBlendEquation(). |
| key |= caps.advBlendEqInteraction() << 2; |
| } |
| if (!xp.hasHWBlendEquation() || caps.mustEnableSpecificAdvBlendEqs()) { |
| GR_STATIC_ASSERT(GrGLSLCaps::kLast_AdvBlendEqInteraction < 4); |
| key |= xp.mode() << 4; |
| } |
| b->add32(key); |
| } |
| |
| private: |
| void onEmitCode(const EmitArgs& args) override { |
| const CustomXP& xp = args.fXP.cast<CustomXP>(); |
| GrGLXPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder(); |
| |
| if (xp.hasHWBlendEquation()) { |
| // The blend mode will be implemented in hardware; only output the src color. |
| fsBuilder->enableAdvancedBlendEquationIfNeeded(xp.hwBlendEquation()); |
| if (xp.readsCoverage()) { |
| // Do coverage modulation by multiplying it into the src color before blending. |
| // (See getOptimizations()) |
| fsBuilder->codeAppendf("%s = %s * %s;", |
| args.fOutputPrimary, args.fInputCoverage, args.fInputColor); |
| } else { |
| fsBuilder->codeAppendf("%s = %s;", args.fOutputPrimary, args.fInputColor); |
| } |
| } else { |
| const char* dstColor = fsBuilder->dstColor(); |
| emit_custom_xfermode_code(xp.mode(), fsBuilder, args.fOutputPrimary, args.fInputColor, |
| dstColor); |
| if (xp.readsCoverage()) { |
| fsBuilder->codeAppendf("%s = %s * %s + (vec4(1.0) - %s) * %s;", |
| args.fOutputPrimary, args.fOutputPrimary, |
| args.fInputCoverage, args.fInputCoverage, dstColor); |
| } |
| } |
| } |
| |
| void onSetData(const GrGLProgramDataManager&, const GrXferProcessor&) override {} |
| |
| typedef GrGLFragmentProcessor INHERITED; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| CustomXP::CustomXP(SkXfermode::Mode mode, const GrDeviceCoordTexture* dstCopy, |
| bool willReadDstColor) |
| : INHERITED(dstCopy, willReadDstColor), |
| fMode(mode), |
| fHWBlendEquation(static_cast<GrBlendEquation>(-1)) { |
| this->initClassID<CustomXP>(); |
| } |
| |
| void CustomXP::onGetGLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const { |
| GLCustomXP::GenKey(*this, caps, b); |
| } |
| |
| GrGLXferProcessor* CustomXP::createGLInstance() const { |
| SkASSERT(this->willReadDstColor() != this->hasHWBlendEquation()); |
| return SkNEW_ARGS(GLCustomXP, (*this)); |
| } |
| |
| bool CustomXP::onIsEqual(const GrXferProcessor& other) const { |
| const CustomXP& s = other.cast<CustomXP>(); |
| return fMode == s.fMode && fHWBlendEquation == s.fHWBlendEquation; |
| } |
| |
| GrXferProcessor::OptFlags CustomXP::onGetOptimizations(const GrProcOptInfo& colorPOI, |
| const GrProcOptInfo& coveragePOI, |
| bool doesStencilWrite, |
| GrColor* overrideColor, |
| const GrCaps& caps) { |
| /* |
| Most the optimizations we do here are based on tweaking alpha for coverage. |
| |
| The general SVG blend equation is defined in the spec as follows: |
| |
| Dca' = B(Sc, Dc) * Sa * Da + Y * Sca * (1-Da) + Z * Dca * (1-Sa) |
| Da' = X * Sa * Da + Y * Sa * (1-Da) + Z * Da * (1-Sa) |
| |
| (Note that Sca, Dca indicate RGB vectors that are premultiplied by alpha, |
| and that B(Sc, Dc) is a mode-specific function that accepts non-multiplied |
| RGB colors.) |
| |
| For every blend mode supported by this class, i.e. the "advanced" blend |
| modes, X=Y=Z=1 and this equation reduces to the PDF blend equation. |
| |
| It can be shown that when X=Y=Z=1, these equations can modulate alpha for |
| coverage. |
| |
| |
| == Color == |
| |
| We substitute Y=Z=1 and define a blend() function that calculates Dca' in |
| terms of premultiplied alpha only: |
| |
| blend(Sca, Dca, Sa, Da) = {Dca : if Sa == 0, |
| Sca : if Da == 0, |
| B(Sca/Sa, Dca/Da) * Sa * Da + Sca * (1-Da) + Dca * (1-Sa) : if Sa,Da != 0} |
| |
| And for coverage modulation, we use a post blend src-over model: |
| |
| Dca'' = f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca |
| |
| (Where f is the fractional coverage.) |
| |
| Next we show that canTweakAlphaForCoverage() is true by proving the |
| following relationship: |
| |
| blend(f*Sca, Dca, f*Sa, Da) == f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca |
| |
| General case (f,Sa,Da != 0): |
| |
| f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca |
| = f * (B(Sca/Sa, Dca/Da) * Sa * Da + Sca * (1-Da) + Dca * (1-Sa)) + (1-f) * Dca [Sa,Da != 0, definition of blend()] |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca * (1-Da) + f*Dca * (1-Sa) + Dca - f*Dca |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca - f*Sca * Da + f*Dca - f*Dca * Sa + Dca - f*Dca |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca - f*Sca * Da - f*Dca * Sa + Dca |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca * (1-Da) - f*Dca * Sa + Dca |
| = B(Sca/Sa, Dca/Da) * f*Sa * Da + f*Sca * (1-Da) + Dca * (1 - f*Sa) |
| = B(f*Sca/f*Sa, Dca/Da) * f*Sa * Da + f*Sca * (1-Da) + Dca * (1 - f*Sa) [f!=0] |
| = blend(f*Sca, Dca, f*Sa, Da) [definition of blend()] |
| |
| Corner cases (Sa=0, Da=0, and f=0): |
| |
| Sa=0: f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca |
| = f * Dca + (1-f) * Dca [Sa=0, definition of blend()] |
| = Dca |
| = blend(0, Dca, 0, Da) [definition of blend()] |
| = blend(f*Sca, Dca, f*Sa, Da) [Sa=0] |
| |
| Da=0: f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca |
| = f * Sca + (1-f) * Dca [Da=0, definition of blend()] |
| = f * Sca [Da=0] |
| = blend(f*Sca, 0, f*Sa, 0) [definition of blend()] |
| = blend(f*Sca, Dca, f*Sa, Da) [Da=0] |
| |
| f=0: f * blend(Sca, Dca, Sa, Da) + (1-f) * Dca |
| = Dca [f=0] |
| = blend(0, Dca, 0, Da) [definition of blend()] |
| = blend(f*Sca, Dca, f*Sa, Da) [f=0] |
| |
| == Alpha == |
| |
| We substitute X=Y=Z=1 and define a blend() function that calculates Da': |
| |
| blend(Sa, Da) = Sa * Da + Sa * (1-Da) + Da * (1-Sa) |
| = Sa * Da + Sa - Sa * Da + Da - Da * Sa |
| = Sa + Da - Sa * Da |
| |
| We use the same model for coverage modulation as we did with color: |
| |
| Da'' = f * blend(Sa, Da) + (1-f) * Da |
| |
| And show that canTweakAlphaForCoverage() is true by proving the following |
| relationship: |
| |
| blend(f*Sa, Da) == f * blend(Sa, Da) + (1-f) * Da |
| |
| |
| f * blend(Sa, Da) + (1-f) * Da |
| = f * (Sa + Da - Sa * Da) + (1-f) * Da |
| = f*Sa + f*Da - f*Sa * Da + Da - f*Da |
| = f*Sa - f*Sa * Da + Da |
| = f*Sa + Da - f*Sa * Da |
| = blend(f*Sa, Da) |
| */ |
| |
| OptFlags flags = kNone_Opt; |
| if (colorPOI.allStagesMultiplyInput()) { |
| flags |= kCanTweakAlphaForCoverage_OptFlag; |
| } |
| if (coveragePOI.isSolidWhite()) { |
| flags |= kIgnoreCoverage_OptFlag; |
| } |
| if (caps.advancedBlendEquationSupport() && !coveragePOI.isFourChannelOutput()) { |
| // This blend mode can be implemented in hardware. |
| fHWBlendEquation = hw_blend_equation(fMode); |
| } |
| return flags; |
| } |
| |
| bool CustomXP::onWillNeedXferBarrier(const GrRenderTarget* rt, |
| const GrCaps& caps, |
| GrXferBarrierType* outBarrierType) const { |
| if (this->hasHWBlendEquation() && !caps.advancedCoherentBlendEquationSupport()) { |
| *outBarrierType = kBlend_GrXferBarrierType; |
| return true; |
| } |
| return false; |
| } |
| |
| void CustomXP::onGetBlendInfo(BlendInfo* blendInfo) const { |
| if (this->hasHWBlendEquation()) { |
| blendInfo->fEquation = this->hwBlendEquation(); |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| GrCustomXPFactory::GrCustomXPFactory(SkXfermode::Mode mode) |
| : fMode(mode) { |
| this->initClassID<GrCustomXPFactory>(); |
| } |
| |
| GrXferProcessor* |
| GrCustomXPFactory::onCreateXferProcessor(const GrCaps& caps, |
| const GrProcOptInfo& colorPOI, |
| const GrProcOptInfo& coveragePOI, |
| const GrDeviceCoordTexture* dstCopy) const { |
| return CustomXP::Create(fMode, dstCopy, this->willReadDstColor(caps, colorPOI, coveragePOI)); |
| } |
| |
| bool GrCustomXPFactory::willReadDstColor(const GrCaps& caps, |
| const GrProcOptInfo& colorPOI, |
| const GrProcOptInfo& coveragePOI) const { |
| if (!caps.advancedBlendEquationSupport()) { |
| // No hardware support for advanced blend equations; we will need to do it in the shader. |
| return true; |
| } |
| if (coveragePOI.isFourChannelOutput()) { |
| // Advanced blend equations can't tweak alpha for RGB coverage. |
| return true; |
| } |
| return false; |
| } |
| |
| void GrCustomXPFactory::getInvariantOutput(const GrProcOptInfo& colorPOI, |
| const GrProcOptInfo& coveragePOI, |
| GrXPFactory::InvariantOutput* output) const { |
| output->fWillBlendWithDst = true; |
| output->fBlendedColorFlags = 0; |
| } |
| |
| GR_DEFINE_XP_FACTORY_TEST(GrCustomXPFactory); |
| GrXPFactory* GrCustomXPFactory::TestCreate(SkRandom* rand, |
| GrContext*, |
| const GrCaps&, |
| GrTexture*[]) { |
| int mode = rand->nextRangeU(SkXfermode::kLastCoeffMode + 1, SkXfermode::kLastSeparableMode); |
| |
| return SkNEW_ARGS(GrCustomXPFactory, (static_cast<SkXfermode::Mode>(mode))); |
| } |
| |
