blob: 2433a70e771b07cc47164db25d39dad8cf897693 [file] [log] [blame]
* 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 "src/gpu/glsl/GrGLSLGeometryProcessor.h"
#include "src/gpu/GrCoordTransform.h"
#include "src/gpu/GrPipeline.h"
#include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h"
#include "src/gpu/glsl/GrGLSLUniformHandler.h"
#include "src/gpu/glsl/GrGLSLVarying.h"
#include "src/gpu/glsl/GrGLSLVertexGeoBuilder.h"
#include <unordered_map>
void GrGLSLGeometryProcessor::emitCode(EmitArgs& args) {
GrGPArgs gpArgs;
this->onEmitCode(args, &gpArgs);
if (gpArgs.fLocalCoordVar.getType() != kVoid_GrSLType) {
this->collectTransforms(args.fVertBuilder, args.fVaryingHandler, args.fUniformHandler,
gpArgs.fLocalCoordVar, args.fFPCoordTransformHandler);
if (args.fGP.willUseTessellationShaders()) {
// Tessellation shaders are temporarily responsible for integrating their own code strings
// while we work out full support.
GrGLSLVertexBuilder* vBuilder = args.fVertBuilder;
if (!args.fGP.willUseGeoShader()) {
// Emit the vertex position to the hardware in the normalized window coordinates it expects.
SkASSERT(kFloat2_GrSLType == gpArgs.fPositionVar.getType() ||
kFloat3_GrSLType == gpArgs.fPositionVar.getType());
vBuilder->emitNormalizedSkPosition(gpArgs.fPositionVar.c_str(), args.fRTAdjustName,
if (kFloat2_GrSLType == gpArgs.fPositionVar.getType()) {
} else {
// Since we have a geometry shader, leave the vertex position in Skia device space for now.
// The geometry Shader will operate in device space, and then convert the final positions to
// normalized hardware window coordinates under the hood, once everything else has finished.
// The subclass must call setNoPerspective on the varying handler, if applicable.
vBuilder->codeAppendf("sk_Position = float4(%s", gpArgs.fPositionVar.c_str());
switch (gpArgs.fPositionVar.getType()) {
case kFloat_GrSLType:
vBuilder->codeAppend(", 0");
case kFloat2_GrSLType:
vBuilder->codeAppend(", 0");
case kFloat3_GrSLType:
vBuilder->codeAppend(", 1");
case kFloat4_GrSLType:
SK_ABORT("Invalid position var type");
void GrGLSLGeometryProcessor::collectTransforms(GrGLSLVertexBuilder* vb,
GrGLSLVaryingHandler* varyingHandler,
GrGLSLUniformHandler* uniformHandler,
const GrShaderVar& localCoordsVar,
FPCoordTransformHandler* handler) {
SkASSERT(localCoordsVar.getType() == kFloat2_GrSLType ||
localCoordsVar.getType() == kFloat3_GrSLType);
// Cached varyings produced by parent FPs. If parent FPs introduce transformations, but all
// subsequent children are not transformed, they should share the same varying.
std::unordered_map<const GrFragmentProcessor*, GrShaderVar> localCoordsMap;
GrGLSLVarying baseLocalCoord;
auto getBaseLocalCoord = [&baseLocalCoord, &localCoordsVar, vb, varyingHandler]() {
if (baseLocalCoord.type() == kVoid_GrSLType) {
// Initialize to the GP provided coordinate
SkString baseLocalCoordName = SkStringPrintf("LocalCoord");
baseLocalCoord = GrGLSLVarying(localCoordsVar.getType());
varyingHandler->addVarying(baseLocalCoordName.c_str(), &baseLocalCoord);
vb->codeAppendf("%s = %s;\n", baseLocalCoord.vsOut(),
return GrShaderVar(SkString(baseLocalCoord.fsIn()), baseLocalCoord.type(),
for (int i = 0; *handler; ++*handler, ++i) {
auto [coordTransform, fp] = handler->get();
// FIXME: GrCoordTransform is used solely as a vehicle for iterating over all FPs that
// require sample coordinates directly. We should make this iteration lighter weight.
// FPs that use local coordinates need a varying to convey the coordinate. This may be the
// base GP's local coord if transforms have to be computed in the FS, or it may be a unique
// varying that computes the equivalent transformation hierarchy in the VS.
GrShaderVar varyingVar;
// If the FP references local coords, we need to make sure the vertex shader sets up the
// right transforms or pass-through variables for the FP to evaluate in the fragment shader
if (fp.referencesSampleCoords()) {
if (fp.isSampledWithExplicitCoords()) {
// If the FP local coords are evaluated in the fragment shader, we only need to
// produce the original local coordinate to pass into the root; any other situation,
// the FP will have a 2nd parameter to its function and the caller sends the coords
if (!fp.parent()) {
varyingVar = getBaseLocalCoord();
} else {
// The FP's local coordinates are determined by the const/uniform transform
// hierarchy from this FP to the root, and can be computed in the vertex shader.
// If this hierarchy would be the identity transform, then we should use the
// original local coordinate.
// NOTE: The actual transform logic is handled in emitTransformCode(), this just
// needs to determine if a unique varying should be added for the FP.
GrShaderVar transformedLocalCoord;
const GrFragmentProcessor* coordOwner = nullptr;
const GrFragmentProcessor* node = &fp;
while(node) {
SkASSERT(!node->isSampledWithExplicitCoords() &&
(node->sampleMatrix().isNoOp() ||
if (node->sampleMatrix().isConstUniform()) {
// We can stop once we hit an FP that adds transforms; this FP can reuse
// that FPs varying (possibly vivifying it if this was the first use).
transformedLocalCoord = localCoordsMap[node];
coordOwner = node;
} // else intervening FP is an identity transform so skip past it
node = node->parent();
if (coordOwner) {
// The FP will use coordOwner's varying; add varying if this was the first use
if (transformedLocalCoord.getType() == kVoid_GrSLType) {
GrGLSLVarying v(kFloat2_GrSLType);
if (GrSLTypeVecLength(localCoordsVar.getType()) == 3 ||
coordOwner->hasPerspectiveTransform()) {
v = GrGLSLVarying(kFloat3_GrSLType);
SkString strVaryingName;
strVaryingName.printf("TransformedCoords_%d", i);
varyingHandler->addVarying(strVaryingName.c_str(), &v);
fTransformInfos.push_back({GrShaderVar(v.vsOut(), v.type()),
transformedLocalCoord = GrShaderVar(SkString(v.fsIn()), v.type(),
localCoordsMap[coordOwner] = transformedLocalCoord;
varyingVar = transformedLocalCoord;
} else {
// The FP transform hierarchy is the identity, so use the original local coord
varyingVar = getBaseLocalCoord();
if (varyingVar.getType() != kVoid_GrSLType) {
handler->specifyCoordsForCurrCoordTransform(GrShaderVar(), varyingVar);
} else {
// Must stay parallel with calls to handler
void GrGLSLGeometryProcessor::emitTransformCode(GrGLSLVertexBuilder* vb,
GrGLSLUniformHandler* uniformHandler) {
std::unordered_map<const GrFragmentProcessor*, GrShaderVar> localCoordsMap;
for (const auto& tr : fTransformInfos) {
// If we recorded a transform info, its sample matrix must be const/uniform
SkString localCoords;
// Build a concatenated matrix expression that we apply to the root local coord.
// If we have an expression cached from an early FP in the hierarchy chain, we can stop
// there instead of going all the way to the GP.
SkString transformExpression;
const auto* base = tr.fFP;
while(base) {
GrShaderVar cachedBaseCoord = localCoordsMap[base];
if (cachedBaseCoord.getType() != kVoid_GrSLType) {
// Can stop here, as this varying already holds all transforms from higher FPs
if (cachedBaseCoord.getType() == kFloat3_GrSLType) {
localCoords = cachedBaseCoord.getName();
} else {
localCoords = SkStringPrintf("%s.xy1", cachedBaseCoord.getName().c_str());
} else if (base->sampleMatrix().isConstUniform()) {
// The FP knows the matrix expression it's sampled with, but its parent defined
// the uniform (when the expression is not a constant).
GrShaderVar uniform = uniformHandler->liftUniformToVertexShader(
*base->parent(), SkString(base->sampleMatrix().fExpression));
// Accumulate the base matrix expression as a preConcat
SkString matrix;
if (uniform.getType() != kVoid_GrSLType) {
SkASSERT(uniform.getType() == kFloat3x3_GrSLType);
matrix = uniform.getName();
} else {
// No uniform found, so presumably this is a constant
matrix = SkString(base->sampleMatrix().fExpression);
if (!transformExpression.isEmpty()) {
transformExpression.append(" * ");
transformExpression.appendf("(%s)", matrix.c_str());
} else {
// This intermediate FP is just a pass through and doesn't need to be built
// in to the expression, but must visit its parents in case they add transforms
base = base->parent();
if (localCoords.isEmpty()) {
// Must use GP's local coords
if (tr.fLocalCoords.getType() == kFloat3_GrSLType) {
localCoords = tr.fLocalCoords.getName();
} else {
localCoords = SkStringPrintf("%s.xy1", tr.fLocalCoords.getName().c_str());
if (tr.fOutputCoords.getType() == kFloat2_GrSLType) {
vb->codeAppendf("%s = ((%s) * %s).xy", tr.fOutputCoords.getName().c_str(),
} else {
SkASSERT(tr.fOutputCoords.getType() == kFloat3_GrSLType);
vb->codeAppendf("%s = (%s) * %s", tr.fOutputCoords.getName().c_str(),
localCoordsMap.insert({ tr.fFP, tr.fOutputCoords });
void GrGLSLGeometryProcessor::setTransformDataHelper(const GrGLSLProgramDataManager& pdman,
const CoordTransformRange& transformRange) {
int i = 0;
for (auto [transform, fp] : transformRange) {
if (fInstalledTransforms[i].fHandle.isValid()) {
SkMatrix m = GetTransformMatrix(transform, SkMatrix::I());
if (!SkMatrixPriv::CheapEqual(fInstalledTransforms[i].fCurrentValue, m)) {
if (fInstalledTransforms[i].fType == kFloat4_GrSLType) {
float values[4] = {m.getScaleX(), m.getTranslateX(),
m.getScaleY(), m.getTranslateY()};
pdman.set4fv(fInstalledTransforms[i].fHandle.toIndex(), 1, values);
} else {
SkASSERT(!m.isScaleTranslate() || !fp.isSampledWithExplicitCoords());
SkASSERT(fInstalledTransforms[i].fType == kFloat3x3_GrSLType);
pdman.setSkMatrix(fInstalledTransforms[i].fHandle.toIndex(), m);
fInstalledTransforms[i].fCurrentValue = m;
SkASSERT(i == fInstalledTransforms.count());
void GrGLSLGeometryProcessor::setTransform(const GrGLSLProgramDataManager& pdman,
const UniformHandle& uniform,
const SkMatrix& matrix,
SkMatrix* state) const {
if (!uniform.isValid() || (state && SkMatrixPriv::CheapEqual(*state, matrix))) {
// No update needed
if (state) {
*state = matrix;
if (matrix.isScaleTranslate()) {
// ComputeMatrixKey and writeX() assume the uniform is a float4 (can't assert since nothing
// is exposed on a handle, but should be caught lower down).
float values[4] = {matrix.getScaleX(), matrix.getTranslateX(),
matrix.getScaleY(), matrix.getTranslateY()};
pdman.set4fv(uniform, 1, values);
} else {
pdman.setSkMatrix(uniform, matrix);
static void write_vertex_position(GrGLSLVertexBuilder* vertBuilder,
GrGLSLUniformHandler* uniformHandler,
const GrShaderVar& inPos,
const SkMatrix& matrix,
const char* matrixName,
GrShaderVar* outPos,
GrGLSLGeometryProcessor::UniformHandle* matrixUniform) {
SkASSERT(inPos.getType() == kFloat3_GrSLType || inPos.getType() == kFloat2_GrSLType);
SkString outName = vertBuilder->newTmpVarName(inPos.getName().c_str());
if (matrix.isIdentity()) {
// Direct assignment, we won't use a uniform for the matrix.
outPos->set(inPos.getType(), outName.c_str());
vertBuilder->codeAppendf("float%d %s = %s;", GrSLTypeVecLength(inPos.getType()),
outName.c_str(), inPos.getName().c_str());
} else {
bool useCompactTransform = matrix.isScaleTranslate();
const char* mangledMatrixName;
*matrixUniform = uniformHandler->addUniform(nullptr,
useCompactTransform ? kFloat4_GrSLType
: kFloat3x3_GrSLType,
if (inPos.getType() == kFloat3_GrSLType) {
// A float3 stays a float3 whether or not the matrix adds perspective
if (useCompactTransform) {
vertBuilder->codeAppendf("float3 %s = %s.xz1 * %s + %s.yw0;\n",
outName.c_str(), mangledMatrixName,
inPos.getName().c_str(), mangledMatrixName);
} else {
vertBuilder->codeAppendf("float3 %s = %s * %s;\n", outName.c_str(),
mangledMatrixName, inPos.getName().c_str());
outPos->set(kFloat3_GrSLType, outName.c_str());
} else if (matrix.hasPerspective()) {
// A float2 is promoted to a float3 if we add perspective via the matrix
vertBuilder->codeAppendf("float3 %s = (%s * %s.xy1);",
outName.c_str(), mangledMatrixName, inPos.getName().c_str());
outPos->set(kFloat3_GrSLType, outName.c_str());
} else {
if (useCompactTransform) {
vertBuilder->codeAppendf("float2 %s = %s.xz * %s + %s.yw;\n",
outName.c_str(), mangledMatrixName,
inPos.getName().c_str(), mangledMatrixName);
} else {
vertBuilder->codeAppendf("float2 %s = (%s * %s.xy1).xy;\n",
outName.c_str(), mangledMatrixName,
outPos->set(kFloat2_GrSLType, outName.c_str());
void GrGLSLGeometryProcessor::writeOutputPosition(GrGLSLVertexBuilder* vertBuilder,
GrGPArgs* gpArgs,
const char* posName) {
// writeOutputPosition assumes the incoming pos name points to a float2 variable
GrShaderVar inPos(posName, kFloat2_GrSLType);
write_vertex_position(vertBuilder, nullptr, inPos, SkMatrix::I(), "viewMatrix",
&gpArgs->fPositionVar, nullptr);
void GrGLSLGeometryProcessor::writeOutputPosition(GrGLSLVertexBuilder* vertBuilder,
GrGLSLUniformHandler* uniformHandler,
GrGPArgs* gpArgs,
const char* posName,
const SkMatrix& mat,
UniformHandle* viewMatrixUniform) {
GrShaderVar inPos(posName, kFloat2_GrSLType);
write_vertex_position(vertBuilder, uniformHandler, inPos, mat, "viewMatrix",
&gpArgs->fPositionVar, viewMatrixUniform);
void GrGLSLGeometryProcessor::writeLocalCoord(GrGLSLVertexBuilder* vertBuilder,
GrGLSLUniformHandler* uniformHandler,
GrGPArgs* gpArgs,
GrShaderVar localVar,
const SkMatrix& localMatrix,
UniformHandle* localMatrixUniform) {
write_vertex_position(vertBuilder, uniformHandler, localVar, localMatrix, "localMatrix",
&gpArgs->fLocalCoordVar, localMatrixUniform);