/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrShaderVar.h"
#include "GrShaderCaps.h"
#include "GrSwizzle.h"
#include "glsl/GrGLSLShaderBuilder.h"
#include "glsl/GrGLSLColorSpaceXformHelper.h"
#include "glsl/GrGLSLProgramBuilder.h"
GrGLSLShaderBuilder::GrGLSLShaderBuilder(GrGLSLProgramBuilder* program)
: fProgramBuilder(program)
, fInputs(GrGLSLProgramBuilder::kVarsPerBlock)
, fOutputs(GrGLSLProgramBuilder::kVarsPerBlock)
, fFeaturesAddedMask(0)
, fCodeIndex(kCode)
, fFinalized(false) {
// We push back some dummy pointers which will later become our header
for (int i = 0; i <= kCode; i++) {
fShaderStrings.push_back();
fCompilerStrings.push_back(nullptr);
fCompilerStringLengths.push_back(0);
}
this->main() = "void main() {";
}
void GrGLSLShaderBuilder::declAppend(const GrShaderVar& var) {
SkString tempDecl;
var.appendDecl(fProgramBuilder->shaderCaps(), &tempDecl);
this->codeAppendf("%s;", tempDecl.c_str());
}
void GrGLSLShaderBuilder::declareGlobal(const GrShaderVar& v) {
v.appendDecl(this->getProgramBuilder()->shaderCaps(), &this->definitions());
this->definitions().append(";");
}
void GrGLSLShaderBuilder::emitFunction(GrSLType returnType,
const char* name,
int argCnt,
const GrShaderVar* args,
const char* body,
SkString* outName) {
this->functions().append(GrGLSLTypeString(returnType));
fProgramBuilder->nameVariable(outName, '\0', name);
this->functions().appendf(" %s", outName->c_str());
this->functions().append("(");
for (int i = 0; i < argCnt; ++i) {
args[i].appendDecl(fProgramBuilder->shaderCaps(), &this->functions());
if (i < argCnt - 1) {
this->functions().append(", ");
}
}
this->functions().append(") {\n");
this->functions().append(body);
this->functions().append("}\n\n");
}
static inline void append_texture_swizzle(SkString* out, GrSwizzle swizzle) {
if (swizzle != GrSwizzle::RGBA()) {
out->appendf(".%s", swizzle.c_str());
}
}
void GrGLSLShaderBuilder::appendTextureLookup(SkString* out,
SamplerHandle samplerHandle,
const char* coordName,
GrSLType varyingType) const {
const GrShaderVar& sampler = fProgramBuilder->samplerVariable(samplerHandle);
GrSLType samplerType = sampler.getType();
if (samplerType == kTexture2DRectSampler_GrSLType) {
if (varyingType == kVec2f_GrSLType) {
out->appendf("texture(%s, textureSize(%s) * %s)",
sampler.c_str(), sampler.c_str(), coordName);
} else {
out->appendf("texture(%s, vec3(textureSize(%s) * %s.xy, %s.z))",
sampler.c_str(), sampler.c_str(), coordName, coordName);
}
} else {
out->appendf("texture(%s, %s)", sampler.c_str(), coordName);
}
append_texture_swizzle(out, fProgramBuilder->samplerSwizzle(samplerHandle));
}
void GrGLSLShaderBuilder::appendTextureLookup(SamplerHandle samplerHandle,
const char* coordName,
GrSLType varyingType,
GrGLSLColorSpaceXformHelper* colorXformHelper) {
if (colorXformHelper && colorXformHelper->isValid()) {
// With a color gamut transform, we need to wrap the lookup in another function call
SkString lookup;
this->appendTextureLookup(&lookup, samplerHandle, coordName, varyingType);
this->appendColorGamutXform(lookup.c_str(), colorXformHelper);
} else {
this->appendTextureLookup(&this->code(), samplerHandle, coordName, varyingType);
}
}
void GrGLSLShaderBuilder::appendTextureLookupAndModulate(
const char* modulation,
SamplerHandle samplerHandle,
const char* coordName,
GrSLType varyingType,
GrGLSLColorSpaceXformHelper* colorXformHelper) {
SkString lookup;
this->appendTextureLookup(&lookup, samplerHandle, coordName, varyingType);
if (colorXformHelper && colorXformHelper->isValid()) {
SkString xform;
this->appendColorGamutXform(&xform, lookup.c_str(), colorXformHelper);
this->codeAppend((GrGLSLExpr4(modulation) * GrGLSLExpr4(xform)).c_str());
} else {
this->codeAppend((GrGLSLExpr4(modulation) * GrGLSLExpr4(lookup)).c_str());
}
}
void GrGLSLShaderBuilder::appendColorGamutXform(SkString* out,
const char* srcColor,
GrGLSLColorSpaceXformHelper* colorXformHelper) {
// Our color is (r, g, b, a), but we want to multiply (r, g, b, 1) by our matrix, then
// re-insert the original alpha. The supplied srcColor is likely to be of the form
// "texture(...)", and we don't want to evaluate that twice, so wrap everything in a function.
static const GrShaderVar gColorGamutXformArgs[] = {
GrShaderVar("color", kVec4f_GrSLType),
GrShaderVar("xform", kMat44f_GrSLType),
};
SkString functionBody;
// Gamut xform, clamp to destination gamut. We only support/have premultiplied textures, so we
// always just clamp to alpha.
functionBody.append("\tcolor.rgb = clamp((xform * vec4(color.rgb, 1.0)).rgb, 0.0, color.a);\n");
functionBody.append("\treturn color;");
SkString colorGamutXformFuncName;
this->emitFunction(kVec4f_GrSLType,
"colorGamutXform",
SK_ARRAY_COUNT(gColorGamutXformArgs),
gColorGamutXformArgs,
functionBody.c_str(),
&colorGamutXformFuncName);
GrGLSLUniformHandler* uniformHandler = fProgramBuilder->uniformHandler();
out->appendf("%s(%s, %s)", colorGamutXformFuncName.c_str(), srcColor,
uniformHandler->getUniformCStr(colorXformHelper->gamutXformUniform()));
}
void GrGLSLShaderBuilder::appendColorGamutXform(const char* srcColor,
GrGLSLColorSpaceXformHelper* colorXformHelper) {
SkString xform;
this->appendColorGamutXform(&xform, srcColor, colorXformHelper);
this->codeAppend(xform.c_str());
}
void GrGLSLShaderBuilder::appendTexelFetch(SkString* out,
SamplerHandle samplerHandle,
const char* coordExpr) const {
const GrShaderVar& sampler = fProgramBuilder->samplerVariable(samplerHandle);
SkASSERT(fProgramBuilder->shaderCaps()->texelFetchSupport());
SkASSERT(GrSLTypeIsCombinedSamplerType(sampler.getType()));
out->appendf("texelFetch(%s, %s)", sampler.c_str(), coordExpr);
append_texture_swizzle(out, fProgramBuilder->samplerSwizzle(samplerHandle));
}
void GrGLSLShaderBuilder::appendTexelFetch(SamplerHandle samplerHandle, const char* coordExpr) {
this->appendTexelFetch(&this->code(), samplerHandle, coordExpr);
}
void GrGLSLShaderBuilder::appendImageStorageLoad(SkString* out, ImageStorageHandle handle,
const char* coordExpr) {
const GrShaderVar& imageStorage = fProgramBuilder->imageStorageVariable(handle);
out->appendf("imageLoad(%s, %s)", imageStorage.c_str(), coordExpr);
}
void GrGLSLShaderBuilder::appendImageStorageLoad(ImageStorageHandle handle, const char* coordExpr) {
this->appendImageStorageLoad(&this->code(), handle, coordExpr);
}
bool GrGLSLShaderBuilder::addFeature(uint32_t featureBit, const char* extensionName) {
if (featureBit & fFeaturesAddedMask) {
return false;
}
this->extensions().appendf("#extension %s: require\n", extensionName);
fFeaturesAddedMask |= featureBit;
return true;
}
void GrGLSLShaderBuilder::appendDecls(const VarArray& vars, SkString* out) const {
for (int i = 0; i < vars.count(); ++i) {
vars[i].appendDecl(fProgramBuilder->shaderCaps(), out);
out->append(";\n");
}
}
void GrGLSLShaderBuilder::addLayoutQualifier(const char* param, InterfaceQualifier interface) {
SkASSERT(fProgramBuilder->shaderCaps()->generation() >= k330_GrGLSLGeneration ||
fProgramBuilder->shaderCaps()->mustEnableAdvBlendEqs());
fLayoutParams[interface].push_back() = param;
}
void GrGLSLShaderBuilder::compileAndAppendLayoutQualifiers() {
static const char* interfaceQualifierNames[] = {
"in",
"out"
};
for (int interface = 0; interface <= kLastInterfaceQualifier; ++interface) {
const SkTArray<SkString>& params = fLayoutParams[interface];
if (params.empty()) {
continue;
}
this->layoutQualifiers().appendf("layout(%s", params[0].c_str());
for (int i = 1; i < params.count(); ++i) {
this->layoutQualifiers().appendf(", %s", params[i].c_str());
}
this->layoutQualifiers().appendf(") %s;\n", interfaceQualifierNames[interface]);
}
GR_STATIC_ASSERT(0 == GrGLSLShaderBuilder::kIn_InterfaceQualifier);
GR_STATIC_ASSERT(1 == GrGLSLShaderBuilder::kOut_InterfaceQualifier);
GR_STATIC_ASSERT(SK_ARRAY_COUNT(interfaceQualifierNames) == kLastInterfaceQualifier + 1);
}
void GrGLSLShaderBuilder::finalize(uint32_t visibility) {
SkASSERT(!fFinalized);
this->versionDecl() = fProgramBuilder->shaderCaps()->versionDeclString();
this->compileAndAppendLayoutQualifiers();
SkASSERT(visibility);
fProgramBuilder->appendUniformDecls((GrShaderFlags) visibility, &this->uniforms());
this->appendDecls(fInputs, &this->inputs());
this->appendDecls(fOutputs, &this->outputs());
this->onFinalize();
// append the 'footer' to code
this->code().append("}");
for (int i = 0; i <= fCodeIndex; i++) {
fCompilerStrings[i] = fShaderStrings[i].c_str();
fCompilerStringLengths[i] = (int)fShaderStrings[i].size();
}
fFinalized = true;
}