void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override {
const GrBitmapTextGeoProc& btgp = args.fGP.cast<GrBitmapTextGeoProc>();
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(btgp);
const char* atlasSizeInvName;
fAtlasSizeInvUniform = uniformHandler->addUniform(kVertex_GrShaderFlag,
kFloat2_GrSLType,
kHigh_GrSLPrecision,
"AtlasSizeInv",
&atlasSizeInvName);
GrGLSLVarying uv(kFloat2_GrSLType);
GrSLType texIdxType = args.fShaderCaps->integerSupport() ? kInt_GrSLType : kFloat_GrSLType;
GrGLSLVarying texIdx(texIdxType);
append_index_uv_varyings(args, btgp.inTextureCoords().name(), atlasSizeInvName, &uv,
&texIdx, nullptr);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Setup pass through color
if (btgp.hasVertexColor()) {
varyingHandler->addPassThroughAttribute(btgp.inColor(), args.fOutputColor);
} else {
this->setupUniformColor(fragBuilder, uniformHandler, args.fOutputColor,
&fColorUniform);
}
// Setup position
gpArgs->fPositionVar = btgp.inPosition().asShaderVar();
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
btgp.inPosition().asShaderVar(),
btgp.localMatrix(),
args.fFPCoordTransformHandler);
fragBuilder->codeAppend("half4 texColor;");
append_multitexture_lookup(args, btgp.numTextureSamplers(),
texIdx, uv.fsIn(), "texColor");
if (btgp.maskFormat() == kARGB_GrMaskFormat) {
// modulate by color
fragBuilder->codeAppendf("%s = %s * texColor;", args.fOutputColor, args.fOutputColor);
fragBuilder->codeAppendf("%s = half4(1);", args.fOutputCoverage);
} else {
fragBuilder->codeAppendf("%s = texColor;", args.fOutputCoverage);
}
}
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);
const char* atlasSizeInvName;
fAtlasSizeInvUniform = uniformHandler->addUniform(kVertex_GrShaderFlag,
kFloat2_GrSLType,
kHigh_GrSLPrecision,
"AtlasSizeInv",
&atlasSizeInvName);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
// setup pass through color
varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
// Setup position
gpArgs->fPositionVar = dfTexEffect.inPosition()->asShaderVar();
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
dfTexEffect.inPosition()->asShaderVar(),
dfTexEffect.localMatrix(),
args.fFPCoordTransformHandler);
// set up varyings
GrGLSLVarying uv(kFloat2_GrSLType);
GrSLType texIdxType = args.fShaderCaps->integerSupport() ? kInt_GrSLType : kFloat_GrSLType;
GrGLSLVarying texIdx(texIdxType);
GrGLSLVarying st(kFloat2_GrSLType);
append_index_uv_varyings(args, dfTexEffect.inTextureCoords()->fName, atlasSizeInvName,
&uv, &texIdx, &st);
GrGLSLVarying delta(kFloat_GrSLType);
varyingHandler->addVarying("Delta", &delta);
if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
vertBuilder->codeAppendf("%s = -%s.x/3.0;", delta.vsOut(), atlasSizeInvName);
} else {
vertBuilder->codeAppendf("%s = %s.x/3.0;", delta.vsOut(), atlasSizeInvName);
}
// add frag shader code
bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
bool isGammaCorrect =
SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
// create LCD offset adjusted by inverse of transform
// Use highp to work around aliasing issues
fragBuilder->codeAppendf("float2 uv = %s;\n", uv.fsIn());
if (isUniformScale) {
#ifdef SK_VULKAN
fragBuilder->codeAppendf("half st_grad_len = abs(dFdx(%s.x));", st.fsIn());
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppendf("half st_grad_len = abs(dFdy(%s.y));", st.fsIn());
#endif
fragBuilder->codeAppendf("half2 offset = half2(st_grad_len*%s, 0.0);", delta.fsIn());
} 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.
#ifdef SK_VULKAN
fragBuilder->codeAppendf("half2 st_grad = dFdx(%s);", st.fsIn());
fragBuilder->codeAppendf("half2 offset = %s*st_grad;", delta.fsIn());
#else
// We use dFdy because of a Mali 400 bug, and rotate -90 degrees to
// get the gradient in the x direction.
fragBuilder->codeAppendf("half2 st_grad = dFdy(%s);", st.fsIn());
fragBuilder->codeAppendf("half2 offset = %s*half2(st_grad.y, -st_grad.x);",
delta.fsIn());
#endif
fragBuilder->codeAppend("half st_grad_len = length(st_grad);");
} else {
fragBuilder->codeAppendf("half2 st = %s;\n", st.fsIn());
fragBuilder->codeAppend("half2 Jdx = dFdx(st);");
fragBuilder->codeAppend("half2 Jdy = dFdy(st);");
fragBuilder->codeAppendf("half2 offset = %s*Jdx;", delta.fsIn());
}
// sample the texture by index
fragBuilder->codeAppend("half4 texColor;");
append_multitexture_lookup(args, dfTexEffect.numTextureSamplers(),
texIdx, "uv", "texColor");
// green is distance to uv center
fragBuilder->codeAppend("half3 distance;");
fragBuilder->codeAppend("distance.y = texColor.r;");
// red is distance to left offset
fragBuilder->codeAppend("half2 uv_adjusted = uv - offset;");
append_multitexture_lookup(args, dfTexEffect.numTextureSamplers(),
texIdx, "uv_adjusted", "texColor");
fragBuilder->codeAppend("distance.x = texColor.r;");
// blue is distance to right offset
fragBuilder->codeAppend("uv_adjusted = uv + offset;");
append_multitexture_lookup(args, dfTexEffect.numTextureSamplers(),
texIdx, "uv_adjusted", "texColor");
fragBuilder->codeAppend("distance.z = texColor.r;");
fragBuilder->codeAppend("distance = "
"half3(" SK_DistanceFieldMultiplier ")*(distance - half3(" SK_DistanceFieldThreshold"));");
// adjust width based on gamma
const char* distanceAdjustUniName = nullptr;
fDistanceAdjustUni = uniformHandler->addUniform(kFragment_GrShaderFlag, kHalf3_GrSLType,
"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("half 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("half2 dist_grad = half2(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("half dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = half2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppend("half2 grad = half2(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->codeAppendf("%s = "
"half4(clamp((distance + half3(afwidth)) / half3(2.0 * afwidth), 0.0, 1.0), 1.0);",
args.fOutputCoverage);
} else {
fragBuilder->codeAppendf(
"%s = half4(smoothstep(half3(-afwidth), half3(afwidth), distance), 1.0);",
args.fOutputCoverage);
}
}
void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
const GrDistanceFieldPathGeoProc& dfPathEffect =
args.fGP.cast<GrDistanceFieldPathGeoProc>();
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
// emit attributes
varyingHandler->emitAttributes(dfPathEffect);
const char* atlasSizeInvName;
fAtlasSizeInvUniform = uniformHandler->addUniform(kVertex_GrShaderFlag,
kFloat2_GrSLType,
kHigh_GrSLPrecision,
"AtlasSizeInv",
&atlasSizeInvName);
GrGLSLVarying uv(kFloat2_GrSLType);
GrSLType texIdxType = args.fShaderCaps->integerSupport() ? kInt_GrSLType : kFloat_GrSLType;
GrGLSLVarying texIdx(texIdxType);
GrGLSLVarying st(kFloat2_GrSLType);
append_index_uv_varyings(args, dfPathEffect.inTextureCoords()->fName, atlasSizeInvName, &uv,
&texIdx, &st);
// setup pass through color
varyingHandler->addPassThroughAttribute(dfPathEffect.inColor(), args.fOutputColor);
if (dfPathEffect.matrix().hasPerspective()) {
// Setup position
this->writeOutputPosition(vertBuilder,
uniformHandler,
gpArgs,
dfPathEffect.inPosition()->fName,
dfPathEffect.matrix(),
&fMatrixUniform);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
dfPathEffect.inPosition()->asShaderVar(),
args.fFPCoordTransformHandler);
} else {
// Setup position
this->writeOutputPosition(vertBuilder, gpArgs, dfPathEffect.inPosition()->fName);
// emit transforms
this->emitTransforms(vertBuilder,
varyingHandler,
uniformHandler,
dfPathEffect.inPosition()->asShaderVar(),
dfPathEffect.matrix(),
args.fFPCoordTransformHandler);
}
// Use highp to work around aliasing issues
fragBuilder->codeAppendf("float2 uv = %s;", uv.fsIn());
fragBuilder->codeAppend("half4 texColor;");
append_multitexture_lookup(args, dfPathEffect.numTextureSamplers(), texIdx, "uv",
"texColor");
fragBuilder->codeAppend("half distance = "
SK_DistanceFieldMultiplier "*(texColor.r - " SK_DistanceFieldThreshold ");");
fragBuilder->codeAppend("half afwidth;");
bool isUniformScale = (dfPathEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
kUniformScale_DistanceFieldEffectMask;
bool isSimilarity = SkToBool(dfPathEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
bool isGammaCorrect =
SkToBool(dfPathEffect.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->codeAppendf("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdx(%s.x));",
st.fsIn());
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppendf("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(%s.y));",
st.fsIn());
#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->codeAppendf("half st_grad_len = length(dFdx(%s));", st.fsIn());
#else
// We use the y gradient because there is a bug in the Mali 400 in the x direction.
fragBuilder->codeAppendf("half st_grad_len = length(dFdy(%s));", st.fsIn());
#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("half2 dist_grad = half2(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("half dg_len2 = dot(dist_grad, dist_grad);");
fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
fragBuilder->codeAppend("dist_grad = half2(0.7071, 0.7071);");
fragBuilder->codeAppend("} else {");
fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
fragBuilder->codeAppend("}");
fragBuilder->codeAppendf("half2 Jdx = dFdx(%s);", st.fsIn());
fragBuilder->codeAppendf("half2 Jdy = dFdy(%s);", st.fsIn());
fragBuilder->codeAppend("half2 grad = half2(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(
"half val = clamp((distance + afwidth) / (2.0 * afwidth), 0.0, 1.0);");
} else {
fragBuilder->codeAppend("half val = smoothstep(-afwidth, afwidth, distance);");
}
fragBuilder->codeAppendf("%s = half4(val);", args.fOutputCoverage);
}
