/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkSLGLSLCodeGenerator.h"
#include "SkSLCompiler.h"
#include "ir/SkSLExpressionStatement.h"
#include "ir/SkSLExtension.h"
#include "ir/SkSLIndexExpression.h"
#include "ir/SkSLModifiersDeclaration.h"
#include "ir/SkSLNop.h"
#include "ir/SkSLVariableReference.h"
#ifndef SKSL_STANDALONE
#include "SkOnce.h"
#endif
namespace SkSL {
void GLSLCodeGenerator::write(const char* s) {
if (s[0] == 0) {
return;
}
if (fAtLineStart) {
for (int i = 0; i < fIndentation; i++) {
fOut->writeText(" ");
}
}
fOut->writeText(s);
fAtLineStart = false;
}
void GLSLCodeGenerator::writeLine(const char* s) {
this->write(s);
fOut->writeText(fLineEnding);
fAtLineStart = true;
}
void GLSLCodeGenerator::write(const String& s) {
this->write(s.c_str());
}
void GLSLCodeGenerator::write(StringFragment s) {
if (!s.fLength) {
return;
}
if (fAtLineStart) {
for (int i = 0; i < fIndentation; i++) {
fOut->writeText(" ");
}
}
fOut->write(s.fChars, s.fLength);
fAtLineStart = false;
}
void GLSLCodeGenerator::writeLine(const String& s) {
this->writeLine(s.c_str());
}
void GLSLCodeGenerator::writeLine() {
this->writeLine("");
}
void GLSLCodeGenerator::writeExtension(const String& name) {
this->writeExtension(name, true);
}
void GLSLCodeGenerator::writeExtension(const String& name, bool require) {
fExtensions.writeText("#extension ");
fExtensions.write(name.c_str(), name.length());
fExtensions.writeText(require ? " : require\n" : " : enable\n");
}
bool GLSLCodeGenerator::usesPrecisionModifiers() const {
return fProgram.fSettings.fCaps->usesPrecisionModifiers();
}
String GLSLCodeGenerator::getTypeName(const Type& type) {
switch (type.kind()) {
case Type::kVector_Kind: {
Type component = type.componentType();
String result;
if (component == *fContext.fFloat_Type || component == *fContext.fHalf_Type) {
result = "vec";
}
else if (component == *fContext.fDouble_Type) {
result = "dvec";
}
else if (component == *fContext.fInt_Type ||
component == *fContext.fShort_Type ||
component == *fContext.fByte_Type) {
result = "ivec";
}
else if (component == *fContext.fUInt_Type ||
component == *fContext.fUShort_Type ||
component == *fContext.fUByte_Type) {
result = "uvec";
}
else if (component == *fContext.fBool_Type) {
result = "bvec";
}
else {
ABORT("unsupported vector type");
}
result += to_string(type.columns());
return result;
}
case Type::kMatrix_Kind: {
String result;
Type component = type.componentType();
if (component == *fContext.fFloat_Type || component == *fContext.fHalf_Type) {
result = "mat";
}
else if (component == *fContext.fDouble_Type) {
result = "dmat";
}
else {
ABORT("unsupported matrix type");
}
result += to_string(type.columns());
if (type.columns() != type.rows()) {
result += "x";
result += to_string(type.rows());
}
return result;
}
case Type::kArray_Kind: {
String result = this->getTypeName(type.componentType()) + "[";
if (type.columns() != -1) {
result += to_string(type.columns());
}
result += "]";
return result;
}
case Type::kScalar_Kind: {
if (type == *fContext.fHalf_Type) {
return "float";
}
else if (type == *fContext.fShort_Type) {
return "int";
}
else if (type == *fContext.fUShort_Type) {
return "uint";
}
else if (type == *fContext.fByte_Type) {
return "int";
}
else if (type == *fContext.fUByte_Type) {
return "uint";
}
else {
return type.name();
}
break;
}
default:
return type.name();
}
}
void GLSLCodeGenerator::writeType(const Type& type) {
if (type.kind() == Type::kStruct_Kind) {
for (const Type* search : fWrittenStructs) {
if (*search == type) {
// already written
this->write(type.fName);
return;
}
}
fWrittenStructs.push_back(&type);
this->write("struct ");
this->write(type.fName);
this->writeLine(" {");
fIndentation++;
for (const auto& f : type.fields()) {
this->writeModifiers(f.fModifiers, false);
this->writeTypePrecision(*f.fType);
// sizes (which must be static in structs) are part of the type name here
this->writeType(*f.fType);
this->write(" ");
this->write(f.fName);
this->writeLine(";");
}
fIndentation--;
this->write("}");
} else {
this->write(this->getTypeName(type));
}
}
void GLSLCodeGenerator::writeExpression(const Expression& expr, Precedence parentPrecedence) {
switch (expr.fKind) {
case Expression::kBinary_Kind:
this->writeBinaryExpression((BinaryExpression&) expr, parentPrecedence);
break;
case Expression::kBoolLiteral_Kind:
this->writeBoolLiteral((BoolLiteral&) expr);
break;
case Expression::kConstructor_Kind:
this->writeConstructor((Constructor&) expr, parentPrecedence);
break;
case Expression::kIntLiteral_Kind:
this->writeIntLiteral((IntLiteral&) expr);
break;
case Expression::kFieldAccess_Kind:
this->writeFieldAccess(((FieldAccess&) expr));
break;
case Expression::kFloatLiteral_Kind:
this->writeFloatLiteral(((FloatLiteral&) expr));
break;
case Expression::kFunctionCall_Kind:
this->writeFunctionCall((FunctionCall&) expr);
break;
case Expression::kPrefix_Kind:
this->writePrefixExpression((PrefixExpression&) expr, parentPrecedence);
break;
case Expression::kPostfix_Kind:
this->writePostfixExpression((PostfixExpression&) expr, parentPrecedence);
break;
case Expression::kSetting_Kind:
this->writeSetting((Setting&) expr);
break;
case Expression::kSwizzle_Kind:
this->writeSwizzle((Swizzle&) expr);
break;
case Expression::kVariableReference_Kind:
this->writeVariableReference((VariableReference&) expr);
break;
case Expression::kTernary_Kind:
this->writeTernaryExpression((TernaryExpression&) expr, parentPrecedence);
break;
case Expression::kIndex_Kind:
this->writeIndexExpression((IndexExpression&) expr);
break;
default:
ABORT("unsupported expression: %s", expr.description().c_str());
}
}
static bool is_abs(Expression& expr) {
if (expr.fKind != Expression::kFunctionCall_Kind) {
return false;
}
return ((FunctionCall&) expr).fFunction.fName == "abs";
}
// turns min(abs(x), y) into ((tmpVar1 = abs(x)) < (tmpVar2 = y) ? tmpVar1 : tmpVar2) to avoid a
// Tegra3 compiler bug.
void GLSLCodeGenerator::writeMinAbsHack(Expression& absExpr, Expression& otherExpr) {
SkASSERT(!fProgram.fSettings.fCaps->canUseMinAndAbsTogether());
String tmpVar1 = "minAbsHackVar" + to_string(fVarCount++);
String tmpVar2 = "minAbsHackVar" + to_string(fVarCount++);
this->fFunctionHeader += String(" ") + this->getTypePrecision(absExpr.fType) +
this->getTypeName(absExpr.fType) + " " + tmpVar1 + ";\n";
this->fFunctionHeader += String(" ") + this->getTypePrecision(otherExpr.fType) +
this->getTypeName(otherExpr.fType) + " " + tmpVar2 + ";\n";
this->write("((" + tmpVar1 + " = ");
this->writeExpression(absExpr, kTopLevel_Precedence);
this->write(") < (" + tmpVar2 + " = ");
this->writeExpression(otherExpr, kAssignment_Precedence);
this->write(") ? " + tmpVar1 + " : " + tmpVar2 + ")");
}
void GLSLCodeGenerator::writeInverseSqrtHack(const Expression& x) {
this->write("(1.0 / sqrt(");
this->writeExpression(x, kTopLevel_Precedence);
this->write("))");
}
void GLSLCodeGenerator::writeDeterminantHack(const Expression& mat) {
String name;
if (mat.fType == *fContext.fFloat2x2_Type || mat.fType == *fContext.fHalf2x2_Type) {
name = "_determinant2";
if (fWrittenIntrinsics.find(name) == fWrittenIntrinsics.end()) {
fWrittenIntrinsics.insert(name);
fExtraFunctions.writeText((
"float " + name + "(mat2 m) {"
" return m[0][0] * m[1][1] - m[0][1] * m[1][0];"
"}"
).c_str());
}
}
else if (mat.fType == *fContext.fFloat3x3_Type || mat.fType == *fContext.fHalf3x3_Type) {
name = "_determinant3";
if (fWrittenIntrinsics.find(name) == fWrittenIntrinsics.end()) {
fWrittenIntrinsics.insert(name);
fExtraFunctions.writeText((
"float " + name + "(mat3 m) {"
" float a00 = m[0][0], a01 = m[0][1], a02 = m[0][2];"
" float a10 = m[1][0], a11 = m[1][1], a12 = m[1][2];"
" float a20 = m[2][0], a21 = m[2][1], a22 = m[2][2];"
" float b01 = a22 * a11 - a12 * a21;"
" float b11 = -a22 * a10 + a12 * a20;"
" float b21 = a21 * a10 - a11 * a20;"
" return a00 * b01 + a01 * b11 + a02 * b21;"
"}"
).c_str());
}
}
else if (mat.fType == *fContext.fFloat4x4_Type || mat.fType == *fContext.fHalf4x4_Type) {
name = "_determinant3";
if (fWrittenIntrinsics.find(name) == fWrittenIntrinsics.end()) {
fWrittenIntrinsics.insert(name);
fExtraFunctions.writeText((
"mat4 " + name + "(mat4 m) {"
" float a00 = m[0][0], a01 = m[0][1], a02 = m[0][2], a03 = m[0][3];"
" float a10 = m[1][0], a11 = m[1][1], a12 = m[1][2], a13 = m[1][3];"
" float a20 = m[2][0], a21 = m[2][1], a22 = m[2][2], a23 = m[2][3];"
" float a30 = m[3][0], a31 = m[3][1], a32 = m[3][2], a33 = m[3][3];"
" float b00 = a00 * a11 - a01 * a10;"
" float b01 = a00 * a12 - a02 * a10;"
" float b02 = a00 * a13 - a03 * a10;"
" float b03 = a01 * a12 - a02 * a11;"
" float b04 = a01 * a13 - a03 * a11;"
" float b05 = a02 * a13 - a03 * a12;"
" float b06 = a20 * a31 - a21 * a30;"
" float b07 = a20 * a32 - a22 * a30;"
" float b08 = a20 * a33 - a23 * a30;"
" float b09 = a21 * a32 - a22 * a31;"
" float b10 = a21 * a33 - a23 * a31;"
" float b11 = a22 * a33 - a23 * a32;"
" return b00 * b11 - b01 * b10 + b02 * b09 + b03 * b08 - b04 * b07 + b05 * b06;"
"}"
).c_str());
}
}
else {
SkASSERT(false);
}
this->write(name + "(");
this->writeExpression(mat, kTopLevel_Precedence);
this->write(")");
}
void GLSLCodeGenerator::writeInverseHack(const Expression& mat) {
String name;
if (mat.fType == *fContext.fFloat2x2_Type || mat.fType == *fContext.fHalf2x2_Type) {
name = "_inverse2";
if (fWrittenIntrinsics.find(name) == fWrittenIntrinsics.end()) {
fWrittenIntrinsics.insert(name);
fExtraFunctions.writeText((
"mat2 " + name + "(mat2 m) {"
" return mat2(m[1][1], -m[0][1], -m[1][0], m[0][0]) / "
"(m[0][0] * m[1][1] - m[0][1] * m[1][0]);"
"}"
).c_str());
}
}
else if (mat.fType == *fContext.fFloat3x3_Type || mat.fType == *fContext.fHalf3x3_Type) {
name = "_inverse3";
if (fWrittenIntrinsics.find(name) == fWrittenIntrinsics.end()) {
fWrittenIntrinsics.insert(name);
fExtraFunctions.writeText((
"mat3 " + name + "(mat3 m) {"
" float a00 = m[0][0], a01 = m[0][1], a02 = m[0][2];"
" float a10 = m[1][0], a11 = m[1][1], a12 = m[1][2];"
" float a20 = m[2][0], a21 = m[2][1], a22 = m[2][2];"
" float b01 = a22 * a11 - a12 * a21;"
" float b11 = -a22 * a10 + a12 * a20;"
" float b21 = a21 * a10 - a11 * a20;"
" float det = a00 * b01 + a01 * b11 + a02 * b21;"
" return mat3(b01, (-a22 * a01 + a02 * a21), (a12 * a01 - a02 * a11),"
" b11, (a22 * a00 - a02 * a20), (-a12 * a00 + a02 * a10),"
" b21, (-a21 * a00 + a01 * a20), (a11 * a00 - a01 * a10)) / det;"
"}"
).c_str());
}
}
else if (mat.fType == *fContext.fFloat4x4_Type || mat.fType == *fContext.fHalf4x4_Type) {
name = "_inverse4";
if (fWrittenIntrinsics.find(name) == fWrittenIntrinsics.end()) {
fWrittenIntrinsics.insert(name);
fExtraFunctions.writeText((
"mat4 " + name + "(mat4 m) {"
" float a00 = m[0][0], a01 = m[0][1], a02 = m[0][2], a03 = m[0][3];"
" float a10 = m[1][0], a11 = m[1][1], a12 = m[1][2], a13 = m[1][3];"
" float a20 = m[2][0], a21 = m[2][1], a22 = m[2][2], a23 = m[2][3];"
" float a30 = m[3][0], a31 = m[3][1], a32 = m[3][2], a33 = m[3][3];"
" float b00 = a00 * a11 - a01 * a10;"
" float b01 = a00 * a12 - a02 * a10;"
" float b02 = a00 * a13 - a03 * a10;"
" float b03 = a01 * a12 - a02 * a11;"
" float b04 = a01 * a13 - a03 * a11;"
" float b05 = a02 * a13 - a03 * a12;"
" float b06 = a20 * a31 - a21 * a30;"
" float b07 = a20 * a32 - a22 * a30;"
" float b08 = a20 * a33 - a23 * a30;"
" float b09 = a21 * a32 - a22 * a31;"
" float b10 = a21 * a33 - a23 * a31;"
" float b11 = a22 * a33 - a23 * a32;"
" float det = b00 * b11 - b01 * b10 + b02 * b09 + b03 * b08 - "
" b04 * b07 + b05 * b06;"
" return mat4("
" a11 * b11 - a12 * b10 + a13 * b09,"
" a02 * b10 - a01 * b11 - a03 * b09,"
" a31 * b05 - a32 * b04 + a33 * b03,"
" a22 * b04 - a21 * b05 - a23 * b03,"
" a12 * b08 - a10 * b11 - a13 * b07,"
" a00 * b11 - a02 * b08 + a03 * b07,"
" a32 * b02 - a30 * b05 - a33 * b01,"
" a20 * b05 - a22 * b02 + a23 * b01,"
" a10 * b10 - a11 * b08 + a13 * b06,"
" a01 * b08 - a00 * b10 - a03 * b06,"
" a30 * b04 - a31 * b02 + a33 * b00,"
" a21 * b02 - a20 * b04 - a23 * b00,"
" a11 * b07 - a10 * b09 - a12 * b06,"
" a00 * b09 - a01 * b07 + a02 * b06,"
" a31 * b01 - a30 * b03 - a32 * b00,"
" a20 * b03 - a21 * b01 + a22 * b00) / det;"
"}"
).c_str());
}
}
else {
SkASSERT(false);
}
this->write(name + "(");
this->writeExpression(mat, kTopLevel_Precedence);
this->write(")");
}
void GLSLCodeGenerator::writeTransposeHack(const Expression& mat) {
String name = "transpose" + to_string(mat.fType.columns()) + to_string(mat.fType.rows());
if (fWrittenIntrinsics.find(name) == fWrittenIntrinsics.end()) {
fWrittenIntrinsics.insert(name);
String type = this->getTypeName(mat.fType);
const Type& base = mat.fType.componentType();
String transposed = this->getTypeName(base.toCompound(fContext,
mat.fType.rows(),
mat.fType.columns()));
fExtraFunctions.writeText((transposed + " " + name + "(" + type + " m) {\nreturn " +
transposed + "(").c_str());
const char* separator = "";
for (int row = 0; row < mat.fType.rows(); ++row) {
for (int column = 0; column < mat.fType.columns(); ++column) {
fExtraFunctions.writeText(separator);
fExtraFunctions.writeText(("m[" + to_string(column) + "][" + to_string(row) +
"]").c_str());
separator = ", ";
}
}
fExtraFunctions.writeText("); }");
}
this->write(name + "(");
this->writeExpression(mat, kTopLevel_Precedence);
this->write(")");
}
std::unordered_map<StringFragment, GLSLCodeGenerator::FunctionClass>*
GLSLCodeGenerator::fFunctionClasses = nullptr;
void GLSLCodeGenerator::writeFunctionCall(const FunctionCall& c) {
#ifdef SKSL_STANDALONE
if (!fFunctionClasses) {
#else
static SkOnce once;
once([] {
#endif
fFunctionClasses = new std::unordered_map<StringFragment, FunctionClass>();
(*fFunctionClasses)["abs"] = FunctionClass::kAbs;
(*fFunctionClasses)["atan"] = FunctionClass::kAtan;
(*fFunctionClasses)["determinant"] = FunctionClass::kDeterminant;
(*fFunctionClasses)["dFdx"] = FunctionClass::kDerivative;
(*fFunctionClasses)["dFdy"] = FunctionClass::kDerivative;
(*fFunctionClasses)["fwidth"] = FunctionClass::kDerivative;
(*fFunctionClasses)["fma"] = FunctionClass::kFMA;
(*fFunctionClasses)["fract"] = FunctionClass::kFract;
(*fFunctionClasses)["inverse"] = FunctionClass::kInverse;
(*fFunctionClasses)["inverseSqrt"] = FunctionClass::kInverseSqrt;
(*fFunctionClasses)["min"] = FunctionClass::kMin;
(*fFunctionClasses)["pow"] = FunctionClass::kPow;
(*fFunctionClasses)["saturate"] = FunctionClass::kSaturate;
(*fFunctionClasses)["texture"] = FunctionClass::kTexture;
(*fFunctionClasses)["transpose"] = FunctionClass::kTranspose;
}
#ifndef SKSL_STANDALONE
);
#endif
const auto found = c.fFunction.fBuiltin ? fFunctionClasses->find(c.fFunction.fName) :
fFunctionClasses->end();
bool isTextureFunctionWithBias = false;
bool nameWritten = false;
if (found != fFunctionClasses->end()) {
switch (found->second) {
case FunctionClass::kAbs: {
if (!fProgram.fSettings.fCaps->emulateAbsIntFunction())
break;
SkASSERT(c.fArguments.size() == 1);
if (c.fArguments[0]->fType != *fContext.fInt_Type)
break;
// abs(int) on Intel OSX is incorrect, so emulate it:
String name = "_absemulation";
this->write(name);
nameWritten = true;
if (fWrittenIntrinsics.find(name) == fWrittenIntrinsics.end()) {
fWrittenIntrinsics.insert(name);
fExtraFunctions.writeText((
"int " + name + "(int x) {\n"
" return x * sign(x);\n"
"}\n"
).c_str());
}
break;
}
case FunctionClass::kAtan:
if (fProgram.fSettings.fCaps->mustForceNegatedAtanParamToFloat() &&
c.fArguments.size() == 2 &&
c.fArguments[1]->fKind == Expression::kPrefix_Kind) {
const PrefixExpression& p = (PrefixExpression&) *c.fArguments[1];
if (p.fOperator == Token::MINUS) {
this->write("atan(");
this->writeExpression(*c.fArguments[0], kSequence_Precedence);
this->write(", -1.0 * ");
this->writeExpression(*p.fOperand, kMultiplicative_Precedence);
this->write(")");
return;
}
}
break;
case FunctionClass::kDerivative:
if (!fFoundDerivatives &&
fProgram.fSettings.fCaps->shaderDerivativeExtensionString()) {
SkASSERT(fProgram.fSettings.fCaps->shaderDerivativeSupport());
this->writeExtension(fProgram.fSettings.fCaps->shaderDerivativeExtensionString());
fFoundDerivatives = true;
}
break;
case FunctionClass::kDeterminant:
if (fProgram.fSettings.fCaps->generation() < k150_GrGLSLGeneration) {
SkASSERT(c.fArguments.size() == 1);
this->writeDeterminantHack(*c.fArguments[0]);
return;
}
break;
case FunctionClass::kFMA:
if (!fProgram.fSettings.fCaps->builtinFMASupport()) {
SkASSERT(c.fArguments.size() == 3);
this->write("((");
this->writeExpression(*c.fArguments[0], kSequence_Precedence);
this->write(") * (");
this->writeExpression(*c.fArguments[1], kSequence_Precedence);
this->write(") + (");
this->writeExpression(*c.fArguments[2], kSequence_Precedence);
this->write("))");
return;
}
break;
case FunctionClass::kFract:
if (!fProgram.fSettings.fCaps->canUseFractForNegativeValues()) {
SkASSERT(c.fArguments.size() == 1);
this->write("(0.5 - sign(");
this->writeExpression(*c.fArguments[0], kSequence_Precedence);
this->write(") * (0.5 - fract(abs(");
this->writeExpression(*c.fArguments[0], kSequence_Precedence);
this->write("))))");
return;
}
break;
case FunctionClass::kInverse:
if (fProgram.fSettings.fCaps->generation() < k140_GrGLSLGeneration) {
SkASSERT(c.fArguments.size() == 1);
this->writeInverseHack(*c.fArguments[0]);
return;
}
break;
case FunctionClass::kInverseSqrt:
if (fProgram.fSettings.fCaps->generation() < k130_GrGLSLGeneration) {
SkASSERT(c.fArguments.size() == 1);
this->writeInverseSqrtHack(*c.fArguments[0]);
return;
}
break;
case FunctionClass::kMin:
if (!fProgram.fSettings.fCaps->canUseMinAndAbsTogether()) {
SkASSERT(c.fArguments.size() == 2);
if (is_abs(*c.fArguments[0])) {
this->writeMinAbsHack(*c.fArguments[0], *c.fArguments[1]);
return;
}
if (is_abs(*c.fArguments[1])) {
// note that this violates the GLSL left-to-right evaluation semantics.
// I doubt it will ever end up mattering, but it's worth calling out.
this->writeMinAbsHack(*c.fArguments[1], *c.fArguments[0]);
return;
}
}
break;
case FunctionClass::kPow:
if (!fProgram.fSettings.fCaps->removePowWithConstantExponent()) {
break;
}
// pow(x, y) on some NVIDIA drivers causes crashes if y is a
// constant. It's hard to tell what constitutes "constant" here
// so just replace in all cases.
// Change pow(x, y) into exp2(y * log2(x))
this->write("exp2(");
this->writeExpression(*c.fArguments[1], kMultiplicative_Precedence);
this->write(" * log2(");
this->writeExpression(*c.fArguments[0], kSequence_Precedence);
this->write("))");
return;
case FunctionClass::kSaturate:
SkASSERT(c.fArguments.size() == 1);
this->write("clamp(");
this->writeExpression(*c.fArguments[0], kSequence_Precedence);
this->write(", 0.0, 1.0)");
return;
case FunctionClass::kTexture: {
const char* dim = "";
bool proj = false;
switch (c.fArguments[0]->fType.dimensions()) {
case SpvDim1D:
dim = "1D";
isTextureFunctionWithBias = true;
if (c.fArguments[1]->fType == *fContext.fFloat_Type) {
proj = false;
} else {
SkASSERT(c.fArguments[1]->fType == *fContext.fFloat2_Type);
proj = true;
}
break;
case SpvDim2D:
dim = "2D";
if (c.fArguments[0]->fType != *fContext.fSamplerExternalOES_Type) {
isTextureFunctionWithBias = true;
}
if (c.fArguments[1]->fType == *fContext.fFloat2_Type) {
proj = false;
} else {
SkASSERT(c.fArguments[1]->fType == *fContext.fFloat3_Type);
proj = true;
}
break;
case SpvDim3D:
dim = "3D";
isTextureFunctionWithBias = true;
if (c.fArguments[1]->fType == *fContext.fFloat3_Type) {
proj = false;
} else {
SkASSERT(c.fArguments[1]->fType == *fContext.fFloat4_Type);
proj = true;
}
break;
case SpvDimCube:
dim = "Cube";
isTextureFunctionWithBias = true;
proj = false;
break;
case SpvDimRect:
dim = "Rect";
proj = false;
break;
case SpvDimBuffer:
SkASSERT(false); // doesn't exist
dim = "Buffer";
proj = false;
break;
case SpvDimSubpassData:
SkASSERT(false); // doesn't exist
dim = "SubpassData";
proj = false;
break;
}
this->write("texture");
if (fProgram.fSettings.fCaps->generation() < k130_GrGLSLGeneration) {
this->write(dim);
}
if (proj) {
this->write("Proj");
}
nameWritten = true;
break;
}
case FunctionClass::kTranspose:
if (fProgram.fSettings.fCaps->generation() < k130_GrGLSLGeneration) {
SkASSERT(c.fArguments.size() == 1);
this->writeTransposeHack(*c.fArguments[0]);
return;
}
break;
}
}
if (!nameWritten) {
this->write(c.fFunction.fName);
}
this->write("(");
const char* separator = "";
for (const auto& arg : c.fArguments) {
this->write(separator);
separator = ", ";
this->writeExpression(*arg, kSequence_Precedence);
}
if (fProgram.fSettings.fSharpenTextures && isTextureFunctionWithBias) {
this->write(", -0.5");
}
this->write(")");
}
void GLSLCodeGenerator::writeConstructor(const Constructor& c, Precedence parentPrecedence) {
if (c.fArguments.size() == 1 &&
this->getTypeName(c.fType) == this->getTypeName(c.fArguments[0]->fType)) {
// in cases like half(float), they're different types as far as SkSL is concerned but the
// same type as far as GLSL is concerned. We avoid a redundant float(float) by just writing
// out the inner expression here.
this->writeExpression(*c.fArguments[0], parentPrecedence);
return;
}
this->writeType(c.fType);
this->write("(");
const char* separator = "";
for (const auto& arg : c.fArguments) {
this->write(separator);
separator = ", ";
this->writeExpression(*arg, kSequence_Precedence);
}
this->write(")");
}
void GLSLCodeGenerator::writeFragCoord() {
if (!fProgram.fSettings.fCaps->canUseFragCoord()) {
if (!fSetupFragCoordWorkaround) {
const char* precision = usesPrecisionModifiers() ? "highp " : "";
fFunctionHeader += precision;
fFunctionHeader += " float sk_FragCoord_InvW = 1. / sk_FragCoord_Workaround.w;\n";
fFunctionHeader += precision;
fFunctionHeader += " vec4 sk_FragCoord_Resolved = "
"vec4(sk_FragCoord_Workaround.xyz * sk_FragCoord_InvW, sk_FragCoord_InvW);\n";
// Ensure that we get exact .5 values for x and y.
fFunctionHeader += " sk_FragCoord_Resolved.xy = floor(sk_FragCoord_Resolved.xy) + "
"vec2(.5);\n";
fSetupFragCoordWorkaround = true;
}
this->write("sk_FragCoord_Resolved");
return;
}
// We only declare "gl_FragCoord" when we're in the case where we want to use layout qualifiers
// to reverse y. Otherwise it isn't necessary and whether the "in" qualifier appears in the
// declaration varies in earlier GLSL specs. So it is simpler to omit it.
if (!fProgram.fSettings.fFlipY) {
this->write("gl_FragCoord");
} else if (const char* extension =
fProgram.fSettings.fCaps->fragCoordConventionsExtensionString()) {
if (!fSetupFragPositionGlobal) {
if (fProgram.fSettings.fCaps->generation() < k150_GrGLSLGeneration) {
this->writeExtension(extension);
}
fGlobals.writeText("layout(origin_upper_left) in vec4 gl_FragCoord;\n");
fSetupFragPositionGlobal = true;
}
this->write("gl_FragCoord");
} else {
if (!fSetupFragPositionLocal) {
fFunctionHeader += usesPrecisionModifiers() ? "highp " : "";
fFunctionHeader += " vec4 sk_FragCoord = vec4(gl_FragCoord.x, " SKSL_RTHEIGHT_NAME
" - gl_FragCoord.y, gl_FragCoord.z, gl_FragCoord.w);\n";
fSetupFragPositionLocal = true;
}
this->write("sk_FragCoord");
}
}
void GLSLCodeGenerator::writeVariableReference(const VariableReference& ref) {
switch (ref.fVariable.fModifiers.fLayout.fBuiltin) {
case SK_FRAGCOLOR_BUILTIN:
if (fProgram.fSettings.fCaps->mustDeclareFragmentShaderOutput()) {
this->write("sk_FragColor");
} else {
this->write("gl_FragColor");
}
break;
case SK_FRAGCOORD_BUILTIN:
this->writeFragCoord();
break;
case SK_WIDTH_BUILTIN:
this->write("u_skRTWidth");
break;
case SK_HEIGHT_BUILTIN:
this->write("u_skRTHeight");
break;
case SK_CLOCKWISE_BUILTIN:
this->write(fProgram.fSettings.fFlipY ? "(!gl_FrontFacing)" : "gl_FrontFacing");
break;
case SK_VERTEXID_BUILTIN:
this->write("gl_VertexID");
break;
case SK_INSTANCEID_BUILTIN:
this->write("gl_InstanceID");
break;
case SK_CLIPDISTANCE_BUILTIN:
this->write("gl_ClipDistance");
break;
case SK_IN_BUILTIN:
this->write("gl_in");
break;
case SK_INVOCATIONID_BUILTIN:
this->write("gl_InvocationID");
break;
case SK_LASTFRAGCOLOR_BUILTIN:
this->write(fProgram.fSettings.fCaps->fbFetchColorName());
break;
default:
this->write(ref.fVariable.fName);
}
}
void GLSLCodeGenerator::writeIndexExpression(const IndexExpression& expr) {
this->writeExpression(*expr.fBase, kPostfix_Precedence);
this->write("[");
this->writeExpression(*expr.fIndex, kTopLevel_Precedence);
this->write("]");
}
bool is_sk_position(const FieldAccess& f) {
return "sk_Position" == f.fBase->fType.fields()[f.fFieldIndex].fName;
}
void GLSLCodeGenerator::writeFieldAccess(const FieldAccess& f) {
if (f.fOwnerKind == FieldAccess::kDefault_OwnerKind) {
this->writeExpression(*f.fBase, kPostfix_Precedence);
this->write(".");
}
switch (f.fBase->fType.fields()[f.fFieldIndex].fModifiers.fLayout.fBuiltin) {
case SK_CLIPDISTANCE_BUILTIN:
this->write("gl_ClipDistance");
break;
default:
StringFragment name = f.fBase->fType.fields()[f.fFieldIndex].fName;
if (name == "sk_Position") {
this->write("gl_Position");
} else if (name == "sk_PointSize") {
this->write("gl_PointSize");
} else {
this->write(f.fBase->fType.fields()[f.fFieldIndex].fName);
}
}
}
void GLSLCodeGenerator::writeSwizzle(const Swizzle& swizzle) {
this->writeExpression(*swizzle.fBase, kPostfix_Precedence);
this->write(".");
for (int c : swizzle.fComponents) {
this->write(&("x\0y\0z\0w\0"[c * 2]));
}
}
GLSLCodeGenerator::Precedence GLSLCodeGenerator::GetBinaryPrecedence(Token::Kind op) {
switch (op) {
case Token::STAR: // fall through
case Token::SLASH: // fall through
case Token::PERCENT: return GLSLCodeGenerator::kMultiplicative_Precedence;
case Token::PLUS: // fall through
case Token::MINUS: return GLSLCodeGenerator::kAdditive_Precedence;
case Token::SHL: // fall through
case Token::SHR: return GLSLCodeGenerator::kShift_Precedence;
case Token::LT: // fall through
case Token::GT: // fall through
case Token::LTEQ: // fall through
case Token::GTEQ: return GLSLCodeGenerator::kRelational_Precedence;
case Token::EQEQ: // fall through
case Token::NEQ: return GLSLCodeGenerator::kEquality_Precedence;
case Token::BITWISEAND: return GLSLCodeGenerator::kBitwiseAnd_Precedence;
case Token::BITWISEXOR: return GLSLCodeGenerator::kBitwiseXor_Precedence;
case Token::BITWISEOR: return GLSLCodeGenerator::kBitwiseOr_Precedence;
case Token::LOGICALAND: return GLSLCodeGenerator::kLogicalAnd_Precedence;
case Token::LOGICALXOR: return GLSLCodeGenerator::kLogicalXor_Precedence;
case Token::LOGICALOR: return GLSLCodeGenerator::kLogicalOr_Precedence;
case Token::EQ: // fall through
case Token::PLUSEQ: // fall through
case Token::MINUSEQ: // fall through
case Token::STAREQ: // fall through
case Token::SLASHEQ: // fall through
case Token::PERCENTEQ: // fall through
case Token::SHLEQ: // fall through
case Token::SHREQ: // fall through
case Token::LOGICALANDEQ: // fall through
case Token::LOGICALXOREQ: // fall through
case Token::LOGICALOREQ: // fall through
case Token::BITWISEANDEQ: // fall through
case Token::BITWISEXOREQ: // fall through
case Token::BITWISEOREQ: return GLSLCodeGenerator::kAssignment_Precedence;
case Token::COMMA: return GLSLCodeGenerator::kSequence_Precedence;
default: ABORT("unsupported binary operator");
}
}
void GLSLCodeGenerator::writeBinaryExpression(const BinaryExpression& b,
Precedence parentPrecedence) {
if (fProgram.fSettings.fCaps->unfoldShortCircuitAsTernary() &&
(b.fOperator == Token::LOGICALAND || b.fOperator == Token::LOGICALOR)) {
this->writeShortCircuitWorkaroundExpression(b, parentPrecedence);
return;
}
Precedence precedence = GetBinaryPrecedence(b.fOperator);
if (precedence >= parentPrecedence) {
this->write("(");
}
bool positionWorkaround = fProgramKind == Program::Kind::kVertex_Kind &&
Compiler::IsAssignment(b.fOperator) &&
Expression::kFieldAccess_Kind == b.fLeft->fKind &&
is_sk_position((FieldAccess&) *b.fLeft) &&
!strstr(b.fRight->description().c_str(), "sk_RTAdjust") &&
!fProgram.fSettings.fCaps->canUseFragCoord();
if (positionWorkaround) {
this->write("sk_FragCoord_Workaround = (");
}
this->writeExpression(*b.fLeft, precedence);
this->write(" ");
this->write(Compiler::OperatorName(b.fOperator));
this->write(" ");
this->writeExpression(*b.fRight, precedence);
if (positionWorkaround) {
this->write(")");
}
if (precedence >= parentPrecedence) {
this->write(")");
}
}
void GLSLCodeGenerator::writeShortCircuitWorkaroundExpression(const BinaryExpression& b,
Precedence parentPrecedence) {
if (kTernary_Precedence >= parentPrecedence) {
this->write("(");
}
// Transform:
// a && b => a ? b : false
// a || b => a ? true : b
this->writeExpression(*b.fLeft, kTernary_Precedence);
this->write(" ? ");
if (b.fOperator == Token::LOGICALAND) {
this->writeExpression(*b.fRight, kTernary_Precedence);
} else {
BoolLiteral boolTrue(fContext, -1, true);
this->writeBoolLiteral(boolTrue);
}
this->write(" : ");
if (b.fOperator == Token::LOGICALAND) {
BoolLiteral boolFalse(fContext, -1, false);
this->writeBoolLiteral(boolFalse);
} else {
this->writeExpression(*b.fRight, kTernary_Precedence);
}
if (kTernary_Precedence >= parentPrecedence) {
this->write(")");
}
}
void GLSLCodeGenerator::writeTernaryExpression(const TernaryExpression& t,
Precedence parentPrecedence) {
if (kTernary_Precedence >= parentPrecedence) {
this->write("(");
}
this->writeExpression(*t.fTest, kTernary_Precedence);
this->write(" ? ");
this->writeExpression(*t.fIfTrue, kTernary_Precedence);
this->write(" : ");
this->writeExpression(*t.fIfFalse, kTernary_Precedence);
if (kTernary_Precedence >= parentPrecedence) {
this->write(")");
}
}
void GLSLCodeGenerator::writePrefixExpression(const PrefixExpression& p,
Precedence parentPrecedence) {
if (kPrefix_Precedence >= parentPrecedence) {
this->write("(");
}
this->write(Compiler::OperatorName(p.fOperator));
this->writeExpression(*p.fOperand, kPrefix_Precedence);
if (kPrefix_Precedence >= parentPrecedence) {
this->write(")");
}
}
void GLSLCodeGenerator::writePostfixExpression(const PostfixExpression& p,
Precedence parentPrecedence) {
if (kPostfix_Precedence >= parentPrecedence) {
this->write("(");
}
this->writeExpression(*p.fOperand, kPostfix_Precedence);
this->write(Compiler::OperatorName(p.fOperator));
if (kPostfix_Precedence >= parentPrecedence) {
this->write(")");
}
}
void GLSLCodeGenerator::writeBoolLiteral(const BoolLiteral& b) {
this->write(b.fValue ? "true" : "false");
}
void GLSLCodeGenerator::writeIntLiteral(const IntLiteral& i) {
if (i.fType == *fContext.fUInt_Type) {
this->write(to_string(i.fValue & 0xffffffff) + "u");
} else if (i.fType == *fContext.fUShort_Type) {
this->write(to_string(i.fValue & 0xffff) + "u");
} else if (i.fType == *fContext.fUByte_Type) {
this->write(to_string(i.fValue & 0xff) + "u");
} else {
this->write(to_string((int32_t) i.fValue));
}
}
void GLSLCodeGenerator::writeFloatLiteral(const FloatLiteral& f) {
this->write(to_string(f.fValue));
}
void GLSLCodeGenerator::writeSetting(const Setting& s) {
ABORT("internal error; setting was not folded to a constant during compilation\n");
}
void GLSLCodeGenerator::writeFunction(const FunctionDefinition& f) {
if (fProgramKind != Program::kPipelineStage_Kind) {
this->writeTypePrecision(f.fDeclaration.fReturnType);
this->writeType(f.fDeclaration.fReturnType);
this->write(" " + f.fDeclaration.fName + "(");
const char* separator = "";
for (const auto& param : f.fDeclaration.fParameters) {
this->write(separator);
separator = ", ";
this->writeModifiers(param->fModifiers, false);
std::vector<int> sizes;
const Type* type = ¶m->fType;
while (type->kind() == Type::kArray_Kind) {
sizes.push_back(type->columns());
type = &type->componentType();
}
this->writeTypePrecision(*type);
this->writeType(*type);
this->write(" " + param->fName);
for (int s : sizes) {
if (s <= 0) {
this->write("[]");
} else {
this->write("[" + to_string(s) + "]");
}
}
}
this->writeLine(") {");
fIndentation++;
}
fFunctionHeader = "";
OutputStream* oldOut = fOut;
StringStream buffer;
fOut = &buffer;
this->writeStatements(((Block&) *f.fBody).fStatements);
if (fProgramKind != Program::kPipelineStage_Kind) {
fIndentation--;
this->writeLine("}");
}
fOut = oldOut;
this->write(fFunctionHeader);
this->write(buffer.str());
}
void GLSLCodeGenerator::writeModifiers(const Modifiers& modifiers,
bool globalContext) {
if (modifiers.fFlags & Modifiers::kFlat_Flag) {
this->write("flat ");
}
if (modifiers.fFlags & Modifiers::kNoPerspective_Flag) {
this->write("noperspective ");
}
String layout = modifiers.fLayout.description();
if (layout.size()) {
this->write(layout + " ");
}
if (modifiers.fFlags & Modifiers::kReadOnly_Flag) {
this->write("readonly ");
}
if (modifiers.fFlags & Modifiers::kWriteOnly_Flag) {
this->write("writeonly ");
}
if (modifiers.fFlags & Modifiers::kCoherent_Flag) {
this->write("coherent ");
}
if (modifiers.fFlags & Modifiers::kVolatile_Flag) {
this->write("volatile ");
}
if (modifiers.fFlags & Modifiers::kRestrict_Flag) {
this->write("restrict ");
}
if ((modifiers.fFlags & Modifiers::kIn_Flag) &&
(modifiers.fFlags & Modifiers::kOut_Flag)) {
this->write("inout ");
} else if (modifiers.fFlags & Modifiers::kIn_Flag) {
if (globalContext &&
fProgram.fSettings.fCaps->generation() < GrGLSLGeneration::k130_GrGLSLGeneration) {
this->write(fProgramKind == Program::kVertex_Kind ? "attribute "
: "varying ");
} else {
this->write("in ");
}
} else if (modifiers.fFlags & Modifiers::kOut_Flag) {
if (globalContext &&
fProgram.fSettings.fCaps->generation() < GrGLSLGeneration::k130_GrGLSLGeneration) {
this->write("varying ");
} else {
this->write("out ");
}
}
if (modifiers.fFlags & Modifiers::kUniform_Flag) {
this->write("uniform ");
}
if (modifiers.fFlags & Modifiers::kConst_Flag) {
this->write("const ");
}
if (modifiers.fFlags & Modifiers::kPLS_Flag) {
this->write("__pixel_localEXT ");
}
if (modifiers.fFlags & Modifiers::kPLSIn_Flag) {
this->write("__pixel_local_inEXT ");
}
if (modifiers.fFlags & Modifiers::kPLSOut_Flag) {
this->write("__pixel_local_outEXT ");
}
if (usesPrecisionModifiers()) {
if (modifiers.fFlags & Modifiers::kLowp_Flag) {
this->write("lowp ");
}
if (modifiers.fFlags & Modifiers::kMediump_Flag) {
this->write("mediump ");
}
if (modifiers.fFlags & Modifiers::kHighp_Flag) {
this->write("highp ");
}
}
}
void GLSLCodeGenerator::writeInterfaceBlock(const InterfaceBlock& intf) {
if (intf.fTypeName == "sk_PerVertex") {
return;
}
this->writeModifiers(intf.fVariable.fModifiers, true);
this->writeLine(intf.fTypeName + " {");
fIndentation++;
const Type* structType = &intf.fVariable.fType;
while (structType->kind() == Type::kArray_Kind) {
structType = &structType->componentType();
}
for (const auto& f : structType->fields()) {
this->writeModifiers(f.fModifiers, false);
this->writeTypePrecision(*f.fType);
this->writeType(*f.fType);
this->writeLine(" " + f.fName + ";");
}
fIndentation--;
this->write("}");
if (intf.fInstanceName.size()) {
this->write(" ");
this->write(intf.fInstanceName);
for (const auto& size : intf.fSizes) {
this->write("[");
if (size) {
this->writeExpression(*size, kTopLevel_Precedence);
}
this->write("]");
}
}
this->writeLine(";");
}
void GLSLCodeGenerator::writeVarInitializer(const Variable& var, const Expression& value) {
this->writeExpression(value, kTopLevel_Precedence);
}
const char* GLSLCodeGenerator::getTypePrecision(const Type& type) {
if (usesPrecisionModifiers()) {
switch (type.kind()) {
case Type::kScalar_Kind:
if (type == *fContext.fShort_Type || type == *fContext.fUShort_Type ||
type == *fContext.fByte_Type || type == *fContext.fUByte_Type) {
if (fProgram.fSettings.fForceHighPrecision ||
fProgram.fSettings.fCaps->incompleteShortIntPrecision()) {
return "highp ";
}
return "mediump ";
}
if (type == *fContext.fHalf_Type) {
return fProgram.fSettings.fForceHighPrecision ? "highp " : "mediump ";
}
if (type == *fContext.fFloat_Type || type == *fContext.fInt_Type ||
type == *fContext.fUInt_Type) {
return "highp ";
}
return "";
case Type::kVector_Kind: // fall through
case Type::kMatrix_Kind:
return this->getTypePrecision(type.componentType());
default:
break;
}
}
return "";
}
void GLSLCodeGenerator::writeTypePrecision(const Type& type) {
this->write(this->getTypePrecision(type));
}
void GLSLCodeGenerator::writeVarDeclarations(const VarDeclarations& decl, bool global) {
if (!decl.fVars.size()) {
return;
}
bool wroteType = false;
for (const auto& stmt : decl.fVars) {
VarDeclaration& var = (VarDeclaration&) *stmt;
if (wroteType) {
this->write(", ");
} else {
this->writeModifiers(var.fVar->fModifiers, global);
this->writeTypePrecision(decl.fBaseType);
this->writeType(decl.fBaseType);
this->write(" ");
wroteType = true;
}
this->write(var.fVar->fName);
for (const auto& size : var.fSizes) {
this->write("[");
if (size) {
this->writeExpression(*size, kTopLevel_Precedence);
}
this->write("]");
}
if (var.fValue) {
this->write(" = ");
this->writeVarInitializer(*var.fVar, *var.fValue);
}
if (!fFoundImageDecl && var.fVar->fType == *fContext.fImage2D_Type) {
if (fProgram.fSettings.fCaps->imageLoadStoreExtensionString()) {
this->writeExtension(fProgram.fSettings.fCaps->imageLoadStoreExtensionString());
}
fFoundImageDecl = true;
}
if (!fFoundExternalSamplerDecl && var.fVar->fType == *fContext.fSamplerExternalOES_Type) {
if (fProgram.fSettings.fCaps->externalTextureExtensionString()) {
this->writeExtension(fProgram.fSettings.fCaps->externalTextureExtensionString());
}
if (fProgram.fSettings.fCaps->secondExternalTextureExtensionString()) {
this->writeExtension(
fProgram.fSettings.fCaps->secondExternalTextureExtensionString());
}
fFoundExternalSamplerDecl = true;
}
}
if (wroteType) {
this->write(";");
}
}
void GLSLCodeGenerator::writeStatement(const Statement& s) {
switch (s.fKind) {
case Statement::kBlock_Kind:
this->writeBlock((Block&) s);
break;
case Statement::kExpression_Kind:
this->writeExpression(*((ExpressionStatement&) s).fExpression, kTopLevel_Precedence);
this->write(";");
break;
case Statement::kReturn_Kind:
this->writeReturnStatement((ReturnStatement&) s);
break;
case Statement::kVarDeclarations_Kind:
this->writeVarDeclarations(*((VarDeclarationsStatement&) s).fDeclaration, false);
break;
case Statement::kIf_Kind:
this->writeIfStatement((IfStatement&) s);
break;
case Statement::kFor_Kind:
this->writeForStatement((ForStatement&) s);
break;
case Statement::kWhile_Kind:
this->writeWhileStatement((WhileStatement&) s);
break;
case Statement::kDo_Kind:
this->writeDoStatement((DoStatement&) s);
break;
case Statement::kSwitch_Kind:
this->writeSwitchStatement((SwitchStatement&) s);
break;
case Statement::kBreak_Kind:
this->write("break;");
break;
case Statement::kContinue_Kind:
this->write("continue;");
break;
case Statement::kDiscard_Kind:
this->write("discard;");
break;
case Statement::kNop_Kind:
this->write(";");
break;
default:
ABORT("unsupported statement: %s", s.description().c_str());
}
}
void GLSLCodeGenerator::writeStatements(const std::vector<std::unique_ptr<Statement>>& statements) {
for (const auto& s : statements) {
if (!s->isEmpty()) {
this->writeStatement(*s);
this->writeLine();
}
}
}
void GLSLCodeGenerator::writeBlock(const Block& b) {
this->writeLine("{");
fIndentation++;
this->writeStatements(b.fStatements);
fIndentation--;
this->write("}");
}
void GLSLCodeGenerator::writeIfStatement(const IfStatement& stmt) {
this->write("if (");
this->writeExpression(*stmt.fTest, kTopLevel_Precedence);
this->write(") ");
this->writeStatement(*stmt.fIfTrue);
if (stmt.fIfFalse) {
this->write(" else ");
this->writeStatement(*stmt.fIfFalse);
}
}
void GLSLCodeGenerator::writeForStatement(const ForStatement& f) {
this->write("for (");
if (f.fInitializer && !f.fInitializer->isEmpty()) {
this->writeStatement(*f.fInitializer);
} else {
this->write("; ");
}
if (f.fTest) {
if (fProgram.fSettings.fCaps->addAndTrueToLoopCondition()) {
std::unique_ptr<Expression> and_true(new BinaryExpression(
-1, f.fTest->clone(), Token::LOGICALAND,
std::unique_ptr<BoolLiteral>(new BoolLiteral(fContext, -1,
true)),
*fContext.fBool_Type));
this->writeExpression(*and_true, kTopLevel_Precedence);
} else {
this->writeExpression(*f.fTest, kTopLevel_Precedence);
}
}
this->write("; ");
if (f.fNext) {
this->writeExpression(*f.fNext, kTopLevel_Precedence);
}
this->write(") ");
this->writeStatement(*f.fStatement);
}
void GLSLCodeGenerator::writeWhileStatement(const WhileStatement& w) {
this->write("while (");
this->writeExpression(*w.fTest, kTopLevel_Precedence);
this->write(") ");
this->writeStatement(*w.fStatement);
}
void GLSLCodeGenerator::writeDoStatement(const DoStatement& d) {
if (!fProgram.fSettings.fCaps->rewriteDoWhileLoops()) {
this->write("do ");
this->writeStatement(*d.fStatement);
this->write(" while (");
this->writeExpression(*d.fTest, kTopLevel_Precedence);
this->write(");");
return;
}
// Otherwise, do the do while loop workaround, to rewrite loops of the form:
// do {
// CODE;
// } while (CONDITION)
//
// to loops of the form
// bool temp = false;
// while (true) {
// if (temp) {
// if (!CONDITION) {
// break;
// }
// }
// temp = true;
// CODE;
// }
String tmpVar = "_tmpLoopSeenOnce" + to_string(fVarCount++);
this->write("bool ");
this->write(tmpVar);
this->writeLine(" = false;");
this->writeLine("while (true) {");
fIndentation++;
this->write("if (");
this->write(tmpVar);
this->writeLine(") {");
fIndentation++;
this->write("if (!");
this->writeExpression(*d.fTest, kPrefix_Precedence);
this->writeLine(") {");
fIndentation++;
this->writeLine("break;");
fIndentation--;
this->writeLine("}");
fIndentation--;
this->writeLine("}");
this->write(tmpVar);
this->writeLine(" = true;");
this->writeStatement(*d.fStatement);
this->writeLine();
fIndentation--;
this->write("}");
}
void GLSLCodeGenerator::writeSwitchStatement(const SwitchStatement& s) {
this->write("switch (");
this->writeExpression(*s.fValue, kTopLevel_Precedence);
this->writeLine(") {");
fIndentation++;
for (const auto& c : s.fCases) {
if (c->fValue) {
this->write("case ");
this->writeExpression(*c->fValue, kTopLevel_Precedence);
this->writeLine(":");
} else {
this->writeLine("default:");
}
fIndentation++;
for (const auto& stmt : c->fStatements) {
this->writeStatement(*stmt);
this->writeLine();
}
fIndentation--;
}
fIndentation--;
this->write("}");
}
void GLSLCodeGenerator::writeReturnStatement(const ReturnStatement& r) {
this->write("return");
if (r.fExpression) {
this->write(" ");
this->writeExpression(*r.fExpression, kTopLevel_Precedence);
}
this->write(";");
}
void GLSLCodeGenerator::writeHeader() {
this->write(fProgram.fSettings.fCaps->versionDeclString());
this->writeLine();
}
void GLSLCodeGenerator::writeProgramElement(const ProgramElement& e) {
switch (e.fKind) {
case ProgramElement::kExtension_Kind:
this->writeExtension(((Extension&) e).fName);
break;
case ProgramElement::kVar_Kind: {
VarDeclarations& decl = (VarDeclarations&) e;
if (decl.fVars.size() > 0) {
int builtin = ((VarDeclaration&) *decl.fVars[0]).fVar->fModifiers.fLayout.fBuiltin;
if (builtin == -1) {
// normal var
this->writeVarDeclarations(decl, true);
this->writeLine();
} else if (builtin == SK_FRAGCOLOR_BUILTIN &&
fProgram.fSettings.fCaps->mustDeclareFragmentShaderOutput() &&
((VarDeclaration&) *decl.fVars[0]).fVar->fWriteCount) {
if (fProgram.fSettings.fFragColorIsInOut) {
this->write("inout ");
} else {
this->write("out ");
}
if (usesPrecisionModifiers()) {
this->write("mediump ");
}
this->writeLine("vec4 sk_FragColor;");
}
}
break;
}
case ProgramElement::kInterfaceBlock_Kind:
this->writeInterfaceBlock((InterfaceBlock&) e);
break;
case ProgramElement::kFunction_Kind:
this->writeFunction((FunctionDefinition&) e);
break;
case ProgramElement::kModifiers_Kind: {
const Modifiers& modifiers = ((ModifiersDeclaration&) e).fModifiers;
if (!fFoundGSInvocations && modifiers.fLayout.fInvocations >= 0) {
if (fProgram.fSettings.fCaps->gsInvocationsExtensionString()) {
this->writeExtension(fProgram.fSettings.fCaps->gsInvocationsExtensionString());
}
fFoundGSInvocations = true;
}
this->writeModifiers(modifiers, true);
this->writeLine(";");
break;
}
case ProgramElement::kEnum_Kind:
break;
default:
printf("%s\n", e.description().c_str());
ABORT("unsupported program element");
}
}
void GLSLCodeGenerator::writeInputVars() {
if (fProgram.fInputs.fRTWidth) {
const char* precision = usesPrecisionModifiers() ? "highp " : "";
fGlobals.writeText("uniform ");
fGlobals.writeText(precision);
fGlobals.writeText("float " SKSL_RTWIDTH_NAME ";\n");
}
if (fProgram.fInputs.fRTHeight) {
const char* precision = usesPrecisionModifiers() ? "highp " : "";
fGlobals.writeText("uniform ");
fGlobals.writeText(precision);
fGlobals.writeText("float " SKSL_RTHEIGHT_NAME ";\n");
}
}
bool GLSLCodeGenerator::generateCode() {
if (fProgramKind != Program::kPipelineStage_Kind) {
this->writeHeader();
}
if (Program::kGeometry_Kind == fProgramKind &&
fProgram.fSettings.fCaps->geometryShaderExtensionString()) {
this->writeExtension(fProgram.fSettings.fCaps->geometryShaderExtensionString());
}
OutputStream* rawOut = fOut;
StringStream body;
fOut = &body;
for (const auto& e : fProgram) {
this->writeProgramElement(e);
}
fOut = rawOut;
write_stringstream(fExtensions, *rawOut);
this->writeInputVars();
write_stringstream(fGlobals, *rawOut);
if (!fProgram.fSettings.fCaps->canUseFragCoord()) {
Layout layout;
switch (fProgram.fKind) {
case Program::kVertex_Kind: {
Modifiers modifiers(layout, Modifiers::kOut_Flag | Modifiers::kHighp_Flag);
this->writeModifiers(modifiers, true);
this->write("vec4 sk_FragCoord_Workaround;\n");
break;
}
case Program::kFragment_Kind: {
Modifiers modifiers(layout, Modifiers::kIn_Flag | Modifiers::kHighp_Flag);
this->writeModifiers(modifiers, true);
this->write("vec4 sk_FragCoord_Workaround;\n");
break;
}
default:
break;
}
}
if (this->usesPrecisionModifiers()) {
this->writeLine("precision mediump float;");
}
write_stringstream(fExtraFunctions, *rawOut);
write_stringstream(body, *rawOut);
return true;
}
}