2 * Copyright 2015 Google Inc.
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
8 #include "GrGLSLFragmentProcessor.h"
9 #include "GrFragmentProcessor.h"
10 #include "GrProcessor.h"
11 #include "glsl/GrGLSLFragmentShaderBuilder.h"
12 #include "glsl/GrGLSLProgramBuilder.h"
14 void GrGLSLFragmentProcessor::setData(const GrGLSLProgramDataManager& pdman,
15 const GrFragmentProcessor& processor) {
16 this->onSetData(pdman, processor);
17 SkASSERT(fChildProcessors.count() == processor.numChildProcessors());
18 for (int i = 0; i < fChildProcessors.count(); ++i) {
19 fChildProcessors[i]->setData(pdman, processor.childProcessor(i));
23 void GrGLSLFragmentProcessor::emitChild(int childIndex, const char* inputColor, EmitArgs& args) {
24 this->internalEmitChild(childIndex, inputColor, args.fOutputColor, args);
27 void GrGLSLFragmentProcessor::emitChild(int childIndex, const char* inputColor,
28 SkString* outputColor, EmitArgs& args) {
30 SkASSERT(outputColor);
31 GrGLSLFragmentBuilder* fb = args.fBuilder->getFragmentShaderBuilder();
32 outputColor->append(fb->getMangleString());
33 fb->codeAppendf("vec4 %s;", outputColor->c_str());
34 this->internalEmitChild(childIndex, inputColor, outputColor->c_str(), args);
37 void GrGLSLFragmentProcessor::internalEmitChild(int childIndex, const char* inputColor,
38 const char* outputColor, EmitArgs& args) {
39 GrGLSLFragmentBuilder* fb = args.fBuilder->getFragmentShaderBuilder();
41 fb->onBeforeChildProcEmitCode(); // call first so mangleString is updated
43 const GrFragmentProcessor& childProc = args.fFp.childProcessor(childIndex);
46 * We now want to find the subset of coords and samplers that belong to the child and its
47 * descendants and put that into childCoords and childSamplers. To do so, we'll do a forwards
51 * Each GrFragmentProcessor has a copy of all the transforms and textures of itself and
52 * all procs in its subtree. For example, suppose we have frag proc A, who has two children B
53 * and D. B has a child C, and D has two children E and F. Each frag proc's transforms array
54 * contains its own transforms, followed by the transforms of all its descendants (i.e. preorder
55 * traversal). Suppose procs A, B, C, D, E, F have 1, 2, 1, 1, 3, 2 transforms respectively.
58 * [a1,b1,b2,c1,d1,e1,e2,e3,f1,f2]
62 * [b1,b2,c1] [d1,e1,e2,e3,f1,f2]
66 * [c1] [e1,e2,e3] [f1,f2]
68 * So if we're inside proc A's emitCode, and A is about to call emitCode on proc D, we want the
69 * EmitArgs that's passed onto D to only contain its and its descendants' coords. The
70 * EmitArgs given to A would contain the transforms [a1,b1,b2,c1,d1,e1,e2,e3,f1,f2], and we want
71 * to extract the subset [d1,e1,e2,e3,f1,f2] to pass on to D. We can do this with a linear
72 * search since we know that A has 1 transform (using A.numTransformsExclChildren()), and B's
73 * subtree has 3 transforms (using B.numTransforms()), so we know the start of D's transforms is
74 * 4 after the start of A's transforms.
75 * Textures work the same way as transforms.
77 int firstCoordAt = args.fFp.numTransformsExclChildren();
78 int firstSamplerAt = args.fFp.numTexturesExclChildren();
79 for (int i = 0; i < childIndex; ++i) {
80 firstCoordAt += args.fFp.childProcessor(i).numTransforms();
81 firstSamplerAt += args.fFp.childProcessor(i).numTextures();
83 GrGLSLTransformedCoordsArray childCoords;
84 TextureSamplerArray childSamplers;
85 if (childProc.numTransforms() > 0) {
86 childCoords.push_back_n(childProc.numTransforms(), &args.fCoords[firstCoordAt]);
88 if (childProc.numTextures() > 0) {
89 childSamplers.push_back_n(childProc.numTextures(), &args.fSamplers[firstSamplerAt]);
92 // emit the code for the child in its own scope
93 fb->codeAppend("{\n");
94 fb->codeAppendf("// Child Index %d (mangle: %s): %s\n", childIndex,
95 fb->getMangleString().c_str(), childProc.name());
96 EmitArgs childArgs(args.fBuilder,
102 this->childProcessor(childIndex)->emitCode(childArgs);
103 fb->codeAppend("}\n");
105 fb->onAfterChildProcEmitCode();