void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const GrRRectShadowGeoProc& rsgp = args.fGP.cast<GrRRectShadowGeoProc>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// emit attributes
varyingHandler->emitAttributes(rsgp);
fragBuilder->codeAppend("vec4 shadowParams;");
varyingHandler->addPassThroughAttribute(rsgp.inShadowParams(), "shadowParams");
// setup pass through color
varyingHandler->addPassThroughAttribute(rsgp.inColor(), args.fOutputColor);
// Setup position
this->setupPosition(vertBuilder, gpArgs, rsgp.inPosition()->fName);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
rsgp.inPosition()->fName,
args.fFPCoordTransformHandler);
fragBuilder->codeAppend("float d = length(shadowParams.xy);");
fragBuilder->codeAppend("float distance = shadowParams.z * (1.0 - d);");
fragBuilder->codeAppend("float factor = 1.0 - clamp(distance, 0.0, shadowParams.w);");
fragBuilder->codeAppend("factor = exp(-factor * factor * 4.0) - 0.018;");
fragBuilder->codeAppendf("%s = vec4(factor);",
args.fOutputCoverage);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const PLSFinishEffect& fe = args.fGP.cast<PLSFinishEffect>();
GrGLSLVertexBuilder* vsBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
fUseEvenOdd = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kLow_GrSLPrecision,
"useEvenOdd");
const char* useEvenOdd = uniformHandler->getUniformCStr(fUseEvenOdd);
varyingHandler->emitAttributes(fe);
this->setupPosition(vsBuilder, gpArgs, fe.inPosition()->fName);
this->emitTransforms(vsBuilder, varyingHandler, uniformHandler, gpArgs->fPositionVar,
fe.inPosition()->fName, fe.localMatrix(), args.fTransformsIn,
args.fTransformsOut);
GrGLSLPPFragmentBuilder* fsBuilder = args.fFragBuilder;
SkAssertResult(fsBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kPixelLocalStorage_GLSLFeature));
fsBuilder->declAppendf(GR_GL_PLS_PATH_DATA_DECL);
fsBuilder->codeAppend("float coverage;");
fsBuilder->codeAppendf("if (%s != 0.0) {", useEvenOdd);
fsBuilder->codeAppend("coverage = float(abs(pls.windings[0]) % 2) * 0.25;");
fsBuilder->codeAppend("coverage += float(abs(pls.windings[1]) % 2) * 0.25;");
fsBuilder->codeAppend("coverage += float(abs(pls.windings[2]) % 2) * 0.25;");
fsBuilder->codeAppend("coverage += float(abs(pls.windings[3]) % 2) * 0.25;");
fsBuilder->codeAppend("} else {");
fsBuilder->codeAppend("coverage = pls.windings[0] != 0 ? 0.25 : 0.0;");
fsBuilder->codeAppend("coverage += pls.windings[1] != 0 ? 0.25 : 0.0;");
fsBuilder->codeAppend("coverage += pls.windings[2] != 0 ? 0.25 : 0.0;");
fsBuilder->codeAppend("coverage += pls.windings[3] != 0 ? 0.25 : 0.0;");
fsBuilder->codeAppend("}");
if (!fe.colorIgnored()) {
this->setupUniformColor(fsBuilder, uniformHandler, args.fOutputColor,
&fColorUniform);
}
fsBuilder->codeAppendf("%s = vec4(coverage);", args.fOutputCoverage);
fsBuilder->codeAppendf("%s = vec4(1.0, 0.0, 1.0, 1.0);", args.fOutputColor);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldLCDTextGeoProc& dfTexEffect =
args.fGP.cast<GrDistanceFieldLCDTextGeoProc>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(dfTexEffect);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// setup pass through color
if (!dfTexEffect.colorIgnored()) {
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
}
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
dfTexEffect.inPosition()->fName,
dfTexEffect.viewMatrix(),
&fViewMatrixUniform);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
dfTexEffect.inPosition()->fName,
args.fTransformsIn,
args.fTransformsOut);
// set up varyings
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
GrGLSLVertToFrag recipScale(kFloat_GrSLType);
GrGLSLVertToFrag uv(kVec2f_GrSLType);
varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);
// compute numbers to be hardcoded to convert texture coordinates from float to int
SkASSERT(dfTexEffect.numTextures() == 1);
GrTexture* atlas = dfTexEffect.textureAccess(0).getTexture();
SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
GrGLSLVertToFrag st(kVec2f_GrSLType);
varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
atlas->width(), atlas->height(),
dfTexEffect.inTextureCoords()->fName);
// add frag shader code
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
// create LCD offset adjusted by inverse of transform
// Use highp to work around aliasing issues
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
fragBuilder->codeAppendf("vec2 uv = %s;\n", uv.fsIn());
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
SkScalar lcdDelta = 1.0f / (3.0f * atlas->width());
if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
fragBuilder->codeAppendf("float delta = -%.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
} else {
fragBuilder->codeAppendf("float delta = %.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
}
if (isUniformScale) {
fragBuilder->codeAppendf("float st_grad_len = abs(dFdy(%s.y));", st.fsIn());
fragBuilder->codeAppend("vec2 offset = vec2(st_grad_len*delta, 0.0);");
} else if (isSimilarity) {
// For a similarity matrix with rotation, the gradient will not be aligned
// with the texel coordinate axes, so we need to calculate it.
// We use dFdy because of a Mali 400 bug, and rotate -90 degrees to
// get the gradient in the x direction.
fragBuilder->codeAppendf("vec2 st_grad = dFdy(%s);", st.fsIn());
fragBuilder->codeAppend("float st_grad_len = length(st_grad);");
fragBuilder->codeAppend("vec2 offset = delta*vec2(st_grad.y, -st_grad.x);");
} else {
fragBuilder->codeAppendf("vec2 st = %s;\n", st.fsIn());
fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
fragBuilder->codeAppend("vec2 offset = delta*Jdx;");
}
// green is distance to uv center
fragBuilder->codeAppend("\tvec4 texColor = ");
fragBuilder->appendTextureLookup(args.fSamplers[0], "uv", kVec2f_GrSLType);
fragBuilder->codeAppend(";\n");
fragBuilder->codeAppend("\tvec3 distance;\n");
fragBuilder->codeAppend("\tdistance.y = texColor.r;\n");
// red is distance to left offset
fragBuilder->codeAppend("\tvec2 uv_adjusted = uv - offset;\n");
fragBuilder->codeAppend("\ttexColor = ");
fragBuilder->appendTextureLookup(args.fSamplers[0], "uv_adjusted", kVec2f_GrSLType);
fragBuilder->codeAppend(";\n");
fragBuilder->codeAppend("\tdistance.x = texColor.r;\n");
// blue is distance to right offset
fragBuilder->codeAppend("\tuv_adjusted = uv + offset;\n");
fragBuilder->codeAppend("\ttexColor = ");
fragBuilder->appendTextureLookup(args.fSamplers[0], "uv_adjusted", kVec2f_GrSLType);
fragBuilder->codeAppend(";\n");
fragBuilder->codeAppend("\tdistance.z = texColor.r;\n");
fragBuilder->codeAppend("\tdistance = "
"vec3(" SK_DistanceFieldMultiplier ")*(distance - vec3(" SK_DistanceFieldThreshold"));");
// adjust width based on gamma
const char* distanceAdjustUniName = nullptr;
fDistanceAdjustUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec3f_GrSLType, kDefault_GrSLPrecision,
"DistanceAdjust", &distanceAdjustUniName);
fragBuilder->codeAppendf("distance -= %s;", distanceAdjustUniName);
// To be strictly correct, we should compute the anti-aliasing factor separately
// for each color component. However, this is only important when using perspective
// transformations, and even then using a single factor seems like a reasonable
// trade-off between quality and speed.
fragBuilder->codeAppend("float afwidth;");
if (isSimilarity) {
// For similarity transform (uniform scale-only is a subset of this), we adjust for the
// effect of the transformation on the distance by using the length of the gradient of
// the texture coordinates. We use st coordinates to ensure we're mapping 1:1 from texel
// space to pixel space.
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*st_grad_len;");
} else {
// For general transforms, to determine the amount of correction we multiply a unit
// vector pointing along the SDF gradient direction by the Jacobian of the st coords
// (which is the inverse transform for this fragment) and take the length of the result.
fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance.r), dFdy(distance.r));");
// the length of the gradient may be 0, so we need to check for this
// this also compensates for the Adreno, which likes to drop tiles on division by 0
fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
}
fragBuilder->codeAppend(
"vec4 val = vec4(smoothstep(vec3(-afwidth), vec3(afwidth), distance), 1.0);");
// set alpha to be max of rgb coverage
fragBuilder->codeAppend("val.a = max(max(val.r, val.g), val.b);");
fragBuilder->codeAppendf("%s = val;", args.fOutputCoverage);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldA8TextGeoProc& dfTexEffect =
args.fGP.cast<GrDistanceFieldA8TextGeoProc>();
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(dfTexEffect);
#ifdef SK_GAMMA_APPLY_TO_A8
// adjust based on gamma
const char* distanceAdjustUniName = nullptr;
// width, height, 1/(3*width)
fDistanceAdjustUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType, kDefault_GrSLPrecision,
"DistanceAdjust", &distanceAdjustUniName);
#endif
// Setup pass through color
if (!dfTexEffect.colorIgnored()) {
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
}
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
dfTexEffect.inPosition()->fName,
dfTexEffect.viewMatrix(),
&fViewMatrixUniform);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
dfTexEffect.inPosition()->fName,
args.fTransformsIn,
args.fTransformsOut);
// add varyings
GrGLSLVertToFrag recipScale(kFloat_GrSLType);
GrGLSLVertToFrag uv(kVec2f_GrSLType);
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);
// compute numbers to be hardcoded to convert texture coordinates from float to int
SkASSERT(dfTexEffect.numTextures() == 1);
GrTexture* atlas = dfTexEffect.textureAccess(0).getTexture();
SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
GrGLSLVertToFrag st(kVec2f_GrSLType);
varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
atlas->width(), atlas->height(),
dfTexEffect.inTextureCoords()->fName);
// Use highp to work around aliasing issues
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
fragBuilder->codeAppendf("vec2 uv = %s;\n", uv.fsIn());
fragBuilder->codeAppend("\tfloat texColor = ");
fragBuilder->appendTextureLookup(args.fSamplers[0],
"uv",
kVec2f_GrSLType);
fragBuilder->codeAppend(".r;\n");
fragBuilder->codeAppend("\tfloat distance = "
SK_DistanceFieldMultiplier "*(texColor - " SK_DistanceFieldThreshold ");");
#ifdef SK_GAMMA_APPLY_TO_A8
// adjust width based on gamma
fragBuilder->codeAppendf("distance -= %s;", distanceAdjustUniName);
#endif
fragBuilder->codeAppend("float afwidth;");
if (isUniformScale) {
// For uniform scale, we adjust for the effect of the transformation on the distance
// by using the length of the gradient of the t coordinate in the y direction.
// We use st coordinates to ensure we're mapping 1:1 from texel space to pixel space.
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppendf("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(%s.y));",
st.fsIn());
} else if (isSimilarity) {
// For similarity transform, we adjust the effect of the transformation on the distance
// by using the length of the gradient of the texture coordinates. We use st coordinates
// to ensure we're mapping 1:1 from texel space to pixel space.
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppendf("float st_grad_len = length(dFdy(%s));", st.fsIn());
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*st_grad_len);");
} else {
// For general transforms, to determine the amount of correction we multiply a unit
// vector pointing along the SDF gradient direction by the Jacobian of the st coords
// (which is the inverse transform for this fragment) and take the length of the result.
fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance), dFdy(distance));");
// the length of the gradient may be 0, so we need to check for this
// this also compensates for the Adreno, which likes to drop tiles on division by 0
fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppendf("vec2 Jdx = dFdx(%s);", st.fsIn());
fragBuilder->codeAppendf("vec2 Jdy = dFdy(%s);", st.fsIn());
fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
}
fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
}
void GrGLQuadEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
const GrQuadEffect& gp = args.fGP.cast<GrQuadEffect>();
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(gp);
GrGLSLVertToFrag v(kVec4f_GrSLType);
varyingHandler->addVarying("HairQuadEdge", &v);
vertBuilder->codeAppendf("%s = %s;", v.vsOut(), gp.inHairQuadEdge()->fName);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup pass through color
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor, &fColorUniform);
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
gp.inPosition()->fName,
gp.viewMatrix(),
&fViewMatrixUniform);
// emit transforms with position
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
gp.inPosition()->fName,
gp.localMatrix(),
args.fFPCoordTransformHandler);
fragBuilder->codeAppendf("float edgeAlpha;");
switch (fEdgeType) {
case kHairlineAA_GrProcessorEdgeType: {
fragBuilder->codeAppendf("vec2 duvdx = dFdx(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 duvdy = dFdy(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 gF = vec2(2.0 * %s.x * duvdx.x - duvdx.y,"
" 2.0 * %s.x * duvdy.x - duvdy.y);",
v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("edgeAlpha = (%s.x * %s.x - %s.y);",
v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppend("edgeAlpha = sqrt(edgeAlpha * edgeAlpha / dot(gF, gF));");
fragBuilder->codeAppend("edgeAlpha = max(1.0 - edgeAlpha, 0.0);");
// Add line below for smooth cubic ramp
// fragBuilder->codeAppend("edgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);");
break;
}
case kFillAA_GrProcessorEdgeType: {
fragBuilder->codeAppendf("vec2 duvdx = dFdx(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 duvdy = dFdy(%s.xy);", v.fsIn());
fragBuilder->codeAppendf("vec2 gF = vec2(2.0 * %s.x * duvdx.x - duvdx.y,"
" 2.0 * %s.x * duvdy.x - duvdy.y);",
v.fsIn(), v.fsIn());
fragBuilder->codeAppendf("edgeAlpha = (%s.x * %s.x - %s.y);",
v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppend("edgeAlpha = edgeAlpha / sqrt(dot(gF, gF));");
fragBuilder->codeAppend("edgeAlpha = clamp(0.5 - edgeAlpha, 0.0, 1.0);");
// Add line below for smooth cubic ramp
// fragBuilder->codeAppend("edgeAlpha = edgeAlpha*edgeAlpha*(3.0-2.0*edgeAlpha);");
break;
}
case kFillBW_GrProcessorEdgeType: {
fragBuilder->codeAppendf("edgeAlpha = (%s.x * %s.x - %s.y);",
v.fsIn(), v.fsIn(), v.fsIn());
fragBuilder->codeAppend("edgeAlpha = float(edgeAlpha < 0.0);");
break;
}
default:
SkFAIL("Shouldn't get here");
}
if (0xff != gp.coverageScale()) {
const char* coverageScale;
fCoverageScaleUniform = uniformHandler->addUniform(kFragment_GrShaderFlag,
kFloat_GrSLType,
kDefault_GrSLPrecision,
"Coverage",
&coverageScale);
fragBuilder->codeAppendf("%s = vec4(%s * edgeAlpha);", args.fOutputCoverage, coverageScale);
} else {
fragBuilder->codeAppendf("%s = vec4(edgeAlpha);", args.fOutputCoverage);
}
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const GrBitmapTextGeoProc& cte = args.fGP.cast<GrBitmapTextGeoProc>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(cte);
// compute numbers to be hardcoded to convert texture coordinates from int to float
SkASSERT(cte.numTextures() == 1);
SkDEBUGCODE(GrTexture* atlas = cte.textureAccess(0).getTexture());
SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
GrGLSLVertToFrag v(kVec2f_GrSLType);
varyingHandler->addVarying("TextureCoords", &v, kHigh_GrSLPrecision);
vertBuilder->codeAppendf("%s = %s;", v.vsOut(),
cte.inTextureCoords()->fName);
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup pass through color
if (!cte.colorIgnored()) {
if (cte.hasVertexColor()) {
varyingHandler->addPassThroughAttribute(cte.inColor(), args.fOutputColor);
} else {
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor,
&fColorUniform);
}
}
// Setup position
this->setupPosition(vertBuilder, gpArgs, cte.inPosition()->fName);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
cte.inPosition()->fName,
cte.localMatrix(),
args.fTransformsIn,
args.fTransformsOut);
if (cte.maskFormat() == kARGB_GrMaskFormat) {
fragBuilder->codeAppendf("%s = ", args.fOutputColor);
fragBuilder->appendTextureLookupAndModulate(args.fOutputColor,
args.fTexSamplers[0],
v.fsIn(),
kVec2f_GrSLType);
fragBuilder->codeAppend(";");
fragBuilder->codeAppendf("%s = vec4(1);", args.fOutputCoverage);
} else {
fragBuilder->codeAppendf("%s = ", args.fOutputCoverage);
fragBuilder->appendTextureLookup(args.fTexSamplers[0], v.fsIn(), kVec2f_GrSLType);
fragBuilder->codeAppend(";");
if (cte.maskFormat() == kA565_GrMaskFormat) {
// set alpha to be max of rgb coverage
fragBuilder->codeAppendf("%s.a = max(max(%s.r, %s.g), %s.b);",
args.fOutputCoverage, args.fOutputCoverage,
args.fOutputCoverage, args.fOutputCoverage);
}
}
}
void GLSLPathProcessor::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
using InstanceAttribs = GrCCPRPathProcessor::InstanceAttribs;
const GrCCPRPathProcessor& proc = args.fGP.cast<GrCCPRPathProcessor>();
GrGLSLUniformHandler* uniHandler = args.fUniformHandler;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
const char* atlasAdjust;
fAtlasAdjustUniform = uniHandler->addUniform(
kVertex_GrShaderFlag,
kVec2f_GrSLType, kHigh_GrSLPrecision, "atlas_adjust", &atlasAdjust);
varyingHandler->emitAttributes(proc);
GrGLSLVertToFrag texcoord(kVec2f_GrSLType);
GrGLSLVertToFrag color(kVec4f_GrSLType);
varyingHandler->addVarying("texcoord", &texcoord, kHigh_GrSLPrecision);
varyingHandler->addFlatPassThroughAttribute(&proc.getInstanceAttrib(InstanceAttribs::kColor),
args.fOutputColor, kLow_GrSLPrecision);
// Vertex shader.
GrGLSLVertexBuilder* v = args.fVertBuilder;
// Find the intersections of (bloated) devBounds and devBounds45 in order to come up with an
// octagon that circumscribes the (bloated) path. A vertex is the intersection of two lines:
// one edge from the path's bounding box and one edge from its 45-degree bounding box.
v->codeAppendf("highp mat2 N = mat2(%s);", proc.getEdgeNormsAttrib().fName);
// N[0] is the normal for the edge we are intersecting from the regular bounding box, pointing
// out of the octagon.
v->codeAppendf("highp vec2 refpt = (min(N[0].x, N[0].y) < 0) ? %s.xy : %s.zw;",
proc.getInstanceAttrib(InstanceAttribs::kDevBounds).fName,
proc.getInstanceAttrib(InstanceAttribs::kDevBounds).fName);
v->codeAppendf("refpt += N[0] * %f;", kAABloatRadius); // bloat for AA.
// N[1] is the normal for the edge we are intersecting from the 45-degree bounding box, pointing
// out of the octagon.
v->codeAppendf("highp vec2 refpt45 = (N[1].x < 0) ? %s.xy : %s.zw;",
proc.getInstanceAttrib(InstanceAttribs::kDevBounds45).fName,
proc.getInstanceAttrib(InstanceAttribs::kDevBounds45).fName);
v->codeAppendf("refpt45 *= mat2(.5,.5,-.5,.5);"); // transform back to device space.
v->codeAppendf("refpt45 += N[1] * %f;", kAABloatRadius); // bloat for AA.
v->codeAppend ("highp vec2 K = vec2(dot(N[0], refpt), dot(N[1], refpt45));");
v->codeAppendf("highp vec2 octocoord = K * inverse(N);");
gpArgs->fPositionVar.set(kVec2f_GrSLType, "octocoord");
// Convert to atlas coordinates in order to do our texture lookup.
v->codeAppendf("highp vec2 atlascoord = octocoord + vec2(%s);",
proc.getInstanceAttrib(InstanceAttribs::kAtlasOffset).fName);
if (kTopLeft_GrSurfaceOrigin == proc.atlas()->origin()) {
v->codeAppendf("%s = atlascoord * %s;", texcoord.vsOut(), atlasAdjust);
} else {
SkASSERT(kBottomLeft_GrSurfaceOrigin == proc.atlas()->origin());
v->codeAppendf("%s = vec2(atlascoord.x * %s.x, 1 - atlascoord.y * %s.y);",
texcoord.vsOut(), atlasAdjust, atlasAdjust);
}
// Convert to (local) path cordinates.
v->codeAppendf("highp vec2 pathcoord = inverse(mat2(%s)) * (octocoord - %s);",
proc.getInstanceAttrib(InstanceAttribs::kViewMatrix).fName,
proc.getInstanceAttrib(InstanceAttribs::kViewTranslate).fName);
this->emitTransforms(v, varyingHandler, uniHandler, gpArgs->fPositionVar, "pathcoord",
args.fFPCoordTransformHandler);
// Fragment shader.
GrGLSLPPFragmentBuilder* f = args.fFragBuilder;
f->codeAppend ("mediump float coverage_count = ");
f->appendTextureLookup(args.fTexSamplers[0], texcoord.fsIn(), kVec2f_GrSLType);
f->codeAppend (".a;");
if (SkPath::kWinding_FillType == proc.fillType()) {
f->codeAppendf("%s = vec4(min(abs(coverage_count), 1));", args.fOutputCoverage);
} else {
SkASSERT(SkPath::kEvenOdd_FillType == proc.fillType());
f->codeAppend ("mediump float t = mod(abs(coverage_count), 2);");
f->codeAppendf("%s = vec4(1 - abs(t - 1));", args.fOutputCoverage);
}
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const PLSQuadEdgeEffect& qe = args.fGP.cast<PLSQuadEdgeEffect>();
GrGLSLVertexBuilder* vsBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(qe);
GrGLSLVertToFrag uv(kVec2f_GrSLType);
varyingHandler->addVarying("uv", &uv, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = %s;", uv.vsOut(), qe.inUV()->fName);
GrGLSLVertToFrag ep1(kVec2f_GrSLType);
varyingHandler->addVarying("endpoint1", &ep1, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);", ep1.vsOut(),
qe.inEndpoint1()->fName, qe.inEndpoint1()->fName);
GrGLSLVertToFrag ep2(kVec2f_GrSLType);
varyingHandler->addVarying("endpoint2", &ep2, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);", ep2.vsOut(),
qe.inEndpoint2()->fName, qe.inEndpoint2()->fName);
GrGLSLVertToFrag delta(kVec2f_GrSLType);
varyingHandler->addVarying("delta", &delta, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x - %s.x, %s.y - %s.y) * 0.5;",
delta.vsOut(), ep1.vsOut(), ep2.vsOut(), ep2.vsOut(),
ep1.vsOut());
GrGLSLVertToFrag windings(kInt_GrSLType);
varyingHandler->addFlatVarying("windings", &windings, kLow_GrSLPrecision);
vsBuilder->codeAppendf("%s = %s;",
windings.vsOut(), qe.inWindings()->fName);
// Setup position
this->setupPosition(vsBuilder, gpArgs, qe.inPosition()->fName);
// emit transforms
this->emitTransforms(vsBuilder, varyingHandler, uniformHandler, gpArgs->fPositionVar,
qe.inPosition()->fName, qe.localMatrix(), args.fTransformsIn,
args.fTransformsOut);
GrGLSLPPFragmentBuilder* fsBuilder = args.fFragBuilder;
SkAssertResult(fsBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kPixelLocalStorage_GLSLFeature));
SkAssertResult(fsBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
static const int QUAD_ARGS = 2;
GrGLSLShaderVar inQuadArgs[QUAD_ARGS] = {
GrGLSLShaderVar("dot", kFloat_GrSLType, 0, kHigh_GrSLPrecision),
GrGLSLShaderVar("uv", kVec2f_GrSLType, 0, kHigh_GrSLPrecision)
};
SkString inQuadName;
const char* inQuadCode = "if (uv.x * uv.x <= uv.y) {"
"return dot >= 0.0;"
"} else {"
"return false;"
"}";
fsBuilder->emitFunction(kBool_GrSLType, "in_quad", QUAD_ARGS, inQuadArgs, inQuadCode,
&inQuadName);
fsBuilder->declAppendf(GR_GL_PLS_PATH_DATA_DECL);
// keep the derivative instructions outside the conditional
fsBuilder->codeAppendf("highp vec2 uvdX = dFdx(%s);", uv.fsIn());
fsBuilder->codeAppendf("highp vec2 uvdY = dFdy(%s);", uv.fsIn());
fsBuilder->codeAppend("highp vec2 uvIncX = uvdX * 0.45 + uvdY * -0.1;");
fsBuilder->codeAppend("highp vec2 uvIncY = uvdX * 0.1 + uvdY * 0.55;");
fsBuilder->codeAppendf("highp vec2 uv = %s.xy - uvdX * 0.35 - uvdY * 0.25;",
uv.fsIn());
fsBuilder->codeAppendf("highp vec2 firstSample = %s.xy - vec2(0.25);",
fsBuilder->fragmentPosition());
fsBuilder->codeAppendf("highp float d = dot(%s, (firstSample - %s).yx) * 2.0;",
delta.fsIn(), ep1.fsIn());
fsBuilder->codeAppendf("pls.windings[0] += %s(d, uv) ? %s : 0;", inQuadName.c_str(),
windings.fsIn());
fsBuilder->codeAppend("uv += uvIncX;");
fsBuilder->codeAppendf("d += %s.x;", delta.fsIn());
fsBuilder->codeAppendf("pls.windings[1] += %s(d, uv) ? %s : 0;", inQuadName.c_str(),
windings.fsIn());
fsBuilder->codeAppend("uv += uvIncY;");
fsBuilder->codeAppendf("d += %s.y;", delta.fsIn());
fsBuilder->codeAppendf("pls.windings[2] += %s(d, uv) ? %s : 0;", inQuadName.c_str(),
windings.fsIn());
fsBuilder->codeAppend("uv -= uvIncX;");
fsBuilder->codeAppendf("d -= %s.x;", delta.fsIn());
fsBuilder->codeAppendf("pls.windings[3] += %s(d, uv) ? %s : 0;", inQuadName.c_str(),
windings.fsIn());
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const PLSAATriangleEffect& te = args.fGP.cast<PLSAATriangleEffect>();
GrGLSLVertexBuilder* vsBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
varyingHandler->emitAttributes(te);
this->setupPosition(vsBuilder, gpArgs, te.inPosition()->fName);
GrGLSLVertToFrag v1(kVec2f_GrSLType);
varyingHandler->addVarying("Vertex1", &v1, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);",
v1.vsOut(),
te.inVertex1()->fName,
te.inVertex1()->fName);
GrGLSLVertToFrag v2(kVec2f_GrSLType);
varyingHandler->addVarying("Vertex2", &v2, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);",
v2.vsOut(),
te.inVertex2()->fName,
te.inVertex2()->fName);
GrGLSLVertToFrag v3(kVec2f_GrSLType);
varyingHandler->addVarying("Vertex3", &v3, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x, %s.y);",
v3.vsOut(),
te.inVertex3()->fName,
te.inVertex3()->fName);
GrGLSLVertToFrag delta1(kVec2f_GrSLType);
varyingHandler->addVarying("delta1", &delta1, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x - %s.x, %s.y - %s.y) * 0.5;",
delta1.vsOut(), v1.vsOut(), v2.vsOut(), v2.vsOut(), v1.vsOut());
GrGLSLVertToFrag delta2(kVec2f_GrSLType);
varyingHandler->addVarying("delta2", &delta2, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x - %s.x, %s.y - %s.y) * 0.5;",
delta2.vsOut(), v2.vsOut(), v3.vsOut(), v3.vsOut(), v2.vsOut());
GrGLSLVertToFrag delta3(kVec2f_GrSLType);
varyingHandler->addVarying("delta3", &delta3, kHigh_GrSLPrecision);
vsBuilder->codeAppendf("%s = vec2(%s.x - %s.x, %s.y - %s.y) * 0.5;",
delta3.vsOut(), v3.vsOut(), v1.vsOut(), v1.vsOut(), v3.vsOut());
GrGLSLVertToFrag windings(kInt_GrSLType);
varyingHandler->addFlatVarying("windings", &windings, kLow_GrSLPrecision);
vsBuilder->codeAppendf("%s = %s;",
windings.vsOut(), te.inWindings()->fName);
// emit transforms
this->emitTransforms(vsBuilder, varyingHandler, uniformHandler, gpArgs->fPositionVar,
te.inPosition()->fName, te.localMatrix(), args.fTransformsIn,
args.fTransformsOut);
GrGLSLPPFragmentBuilder* fsBuilder = args.fFragBuilder;
SkAssertResult(fsBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kPixelLocalStorage_GLSLFeature));
SkAssertResult(fsBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
fsBuilder->declAppendf(GR_GL_PLS_PATH_DATA_DECL);
// Compute four subsamples, each shifted a quarter pixel along x and y from
// gl_FragCoord. The oriented box positioning of the subsamples is of course not
// optimal, but it greatly simplifies the math and this simplification is necessary for
// performance reasons.
fsBuilder->codeAppendf("highp vec2 firstSample = %s.xy - vec2(0.25);",
fsBuilder->fragmentPosition());
fsBuilder->codeAppendf("highp vec2 delta1 = %s;", delta1.fsIn());
fsBuilder->codeAppendf("highp vec2 delta2 = %s;", delta2.fsIn());
fsBuilder->codeAppendf("highp vec2 delta3 = %s;", delta3.fsIn());
// Check whether first sample is inside the triangle by computing three dot products. If
// all are < 0, we're inside. The first vector in each case is half of what it is
// "supposed" to be, because we re-use them later as adjustment factors for which half
// is the correct value, so we multiply the dots by two to compensate.
fsBuilder->codeAppendf("highp float d1 = dot(delta1, (firstSample - %s).yx) * 2.0;",
v1.fsIn());
fsBuilder->codeAppendf("highp float d2 = dot(delta2, (firstSample - %s).yx) * 2.0;",
v2.fsIn());
fsBuilder->codeAppendf("highp float d3 = dot(delta3, (firstSample - %s).yx) * 2.0;",
v3.fsIn());
fsBuilder->codeAppend("highp float dmax = max(d1, max(d2, d3));");
fsBuilder->codeAppendf("pls.windings[0] += (dmax <= 0.0) ? %s : 0;", windings.fsIn());
// for subsequent samples, we don't recalculate the entire dot product -- just adjust it
// to the value it would have if we did recompute it.
fsBuilder->codeAppend("d1 += delta1.x;");
fsBuilder->codeAppend("d2 += delta2.x;");
fsBuilder->codeAppend("d3 += delta3.x;");
fsBuilder->codeAppend("dmax = max(d1, max(d2, d3));");
fsBuilder->codeAppendf("pls.windings[1] += (dmax <= 0.0) ? %s : 0;", windings.fsIn());
fsBuilder->codeAppend("d1 += delta1.y;");
fsBuilder->codeAppend("d2 += delta2.y;");
fsBuilder->codeAppend("d3 += delta3.y;");
fsBuilder->codeAppend("dmax = max(d1, max(d2, d3));");
fsBuilder->codeAppendf("pls.windings[2] += (dmax <= 0.0) ? %s : 0;", windings.fsIn());
fsBuilder->codeAppend("d1 -= delta1.x;");
fsBuilder->codeAppend("d2 -= delta2.x;");
fsBuilder->codeAppend("d3 -= delta3.x;");
fsBuilder->codeAppend("dmax = max(d1, max(d2, d3));");
fsBuilder->codeAppendf("pls.windings[3] += (dmax <= 0.0) ? %s : 0;", windings.fsIn());
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldPathGeoProc& dfTexEffect = args.fGP.cast<GrDistanceFieldPathGeoProc>();
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(dfTexEffect);
GrGLSLVertToFrag v(kVec2f_GrSLType);
varyingHandler->addVarying("TextureCoords", &v, kHigh_GrSLPrecision);
// setup pass through color
if (!dfTexEffect.colorIgnored()) {
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
}
vertBuilder->codeAppendf("%s = %s;", v.vsOut(), dfTexEffect.inTextureCoords()->fName);
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
dfTexEffect.inPosition()->fName,
dfTexEffect.viewMatrix(),
&fViewMatrixUniform);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
dfTexEffect.inPosition()->fName,
args.fFPCoordTransformHandler);
const char* textureSizeUniName = nullptr;
fTextureSizeUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"TextureSize", &textureSizeUniName);
// Use highp to work around aliasing issues
fragBuilder->appendPrecisionModifier(kHigh_GrSLPrecision);
fragBuilder->codeAppendf("vec2 uv = %s;", v.fsIn());
fragBuilder->codeAppend("float texColor = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0],
"uv",
kVec2f_GrSLType);
fragBuilder->codeAppend(".r;");
fragBuilder->codeAppend("float distance = "
SK_DistanceFieldMultiplier "*(texColor - " SK_DistanceFieldThreshold ");");
fragBuilder->appendPrecisionModifier(kHigh_GrSLPrecision);
fragBuilder->codeAppendf("vec2 st = uv*%s;", textureSizeUniName);
fragBuilder->codeAppend("float afwidth;");
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
bool isGammaCorrect =
SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
if (isUniformScale) {
// For uniform scale, we adjust for the effect of the transformation on the distance
// by using the length of the gradient of the t coordinate in the y direction.
// We use st coordinates to ensure we're mapping 1:1 from texel space to pixel space.
// this gives us a smooth step across approximately one fragment
#ifdef SK_VULKAN
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdx(st.x));");
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(st.y));");
#endif
} else if (isSimilarity) {
// For similarity transform, we adjust the effect of the transformation on the distance
// by using the length of the gradient of the texture coordinates. We use st coordinates
// to ensure we're mapping 1:1 from texel space to pixel space.
// this gives us a smooth step across approximately one fragment
#ifdef SK_VULKAN
fragBuilder->codeAppend("float st_grad_len = length(dFdx(st));");
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppend("float st_grad_len = length(dFdy(st));");
#endif
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*st_grad_len);");
} else {
// For general transforms, to determine the amount of correction we multiply a unit
// vector pointing along the SDF gradient direction by the Jacobian of the st coords
// (which is the inverse transform for this fragment) and take the length of the result.
fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance), dFdy(distance));");
// the length of the gradient may be 0, so we need to check for this
// this also compensates for the Adreno, which likes to drop tiles on division by 0
fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
}
// The smoothstep falloff compensates for the non-linear sRGB response curve. If we are
// doing gamma-correct rendering (to an sRGB or F16 buffer), then we actually want distance
// mapped linearly to coverage, so use a linear step:
if (isGammaCorrect) {
fragBuilder->codeAppend(
"float val = clamp(distance + afwidth / (2.0 * afwidth), 0.0, 1.0);");
} else {
fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
}
fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldPathGeoProc& dfTexEffect = args.fGP.cast<GrDistanceFieldPathGeoProc>();
GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkAssertResult(fragBuilder->enableFeature(
GrGLSLFragmentShaderBuilder::kStandardDerivatives_GLSLFeature));
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(dfTexEffect);
GrGLSLVertToFrag v(kVec2f_GrSLType);
varyingHandler->addVarying("TextureCoords", &v, kHigh_GrSLPrecision);
// setup pass through color
if (!dfTexEffect.colorIgnored()) {
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
}
vertBuilder->codeAppendf("%s = %s;", v.vsOut(), dfTexEffect.inTextureCoords()->fName);
// Setup position
this->setupPosition(vertBuilder,
uniformHandler,
gpArgs,
dfTexEffect.inPosition()->fName,
dfTexEffect.viewMatrix(),
&fViewMatrixUniform);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
gpArgs->fPositionVar,
dfTexEffect.inPosition()->fName,
args.fTransformsIn,
args.fTransformsOut);
const char* textureSizeUniName = nullptr;
fTextureSizeUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"TextureSize", &textureSizeUniName);
// Use highp to work around aliasing issues
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
fragBuilder->codeAppendf("vec2 uv = %s;", v.fsIn());
fragBuilder->codeAppend("float texColor = ");
fragBuilder->appendTextureLookup(args.fSamplers[0],
"uv",
kVec2f_GrSLType);
fragBuilder->codeAppend(".r;");
fragBuilder->codeAppend("float distance = "
SK_DistanceFieldMultiplier "*(texColor - " SK_DistanceFieldThreshold ");");
fragBuilder->codeAppend(GrGLSLShaderVar::PrecisionString(args.fGLSLCaps,
kHigh_GrSLPrecision));
fragBuilder->codeAppendf("vec2 st = uv*%s;", textureSizeUniName);
fragBuilder->codeAppend("float afwidth;");
if (dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag) {
// For uniform scale, we adjust for the effect of the transformation on the distance
// by using the length of the gradient of the texture coordinates. We use st coordinates
// to ensure we're mapping 1:1 from texel space to pixel space.
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(st.y));");
} else {
// For general transforms, to determine the amount of correction we multiply a unit
// vector pointing along the SDF gradient direction by the Jacobian of the st coords
// (which is the inverse transform for this fragment) and take the length of the result.
fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance), dFdy(distance));");
// the length of the gradient may be 0, so we need to check for this
// this also compensates for the Adreno, which likes to drop tiles on division by 0
fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
// this gives us a smooth step across approximately one fragment
fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
}
fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
}