Line data    Source code

       1             : /*
       2             :  * Copyright 2014 Google Inc.
       3             :  *
       4             :  * Use of this source code is governed by a BSD-style license that can be
       5             :  * found in the LICENSE file.
       6             :  */
       7             : 
       8             : #include "GrGLSLGeometryShaderBuilder.h"
       9             : #include "GrGLSLProgramBuilder.h"
      10             : #include "GrGLSLVarying.h"
      11             : 
      12           0 : static const char* input_type_name(GrGLSLGeometryBuilder::InputType in) {
      13             :     using InputType = GrGLSLGeometryBuilder::InputType;
      14           0 :     switch (in) {
      15           0 :         case InputType::kPoints: return "points";
      16           0 :         case InputType::kLines: return "lines";
      17           0 :         case InputType::kLinesAdjacency: return "lines_adjacency";
      18           0 :         case InputType::kTriangles: return "triangles";
      19           0 :         case InputType::kTrianglesAdjacency: return "triangles_adjacency";
      20             :     }
      21           0 :     SkFAIL("invalid input type");
      22           0 :     return "unknown_input";
      23             : }
      24             : 
      25           0 : static const char* output_type_name(GrGLSLGeometryBuilder::OutputType out) {
      26             :     using OutputType = GrGLSLGeometryBuilder::OutputType;
      27           0 :     switch (out) {
      28           0 :         case OutputType::kPoints: return "points";
      29           0 :         case OutputType::kLineStrip: return "line_strip";
      30           0 :         case OutputType::kTriangleStrip: return "triangle_strip";
      31             :     }
      32           0 :     SkFAIL("invalid output type");
      33           0 :     return "unknown_output";
      34             : }
      35             : 
      36           0 : GrGLSLGeometryBuilder::GrGLSLGeometryBuilder(GrGLSLProgramBuilder* program)
      37             :     : INHERITED(program)
      38           0 :     , fNumInvocations(0) {
      39           0 : }
      40             : 
      41           0 : void GrGLSLGeometryBuilder::configure(InputType inputType, OutputType outputType, int maxVertices,
      42             :                                       int numInvocations) {
      43           0 :     SkASSERT(!this->isConfigured());
      44           0 :     fNumInvocations = numInvocations;
      45           0 :     if (this->getProgramBuilder()->shaderCaps()->mustImplementGSInvocationsWithLoop()) {
      46           0 :         maxVertices *= numInvocations;
      47           0 :         numInvocations = 1;
      48             :     }
      49           0 :     this->addLayoutQualifier(input_type_name(inputType), kIn_InterfaceQualifier);
      50           0 :     this->addLayoutQualifier(SkStringPrintf("invocations = %i", numInvocations).c_str(),
      51           0 :                              kIn_InterfaceQualifier);
      52           0 :     this->addLayoutQualifier(output_type_name(outputType), kOut_InterfaceQualifier);
      53           0 :     this->addLayoutQualifier(SkStringPrintf("max_vertices = %i", maxVertices).c_str(),
      54           0 :                              kOut_InterfaceQualifier);
      55           0 : }
      56             : 
      57           0 : void GrGLSLGeometryBuilder::onFinalize() {
      58           0 :     SkASSERT(this->isConfigured());
      59           0 :     fProgramBuilder->varyingHandler()->getGeomDecls(&this->inputs(), &this->outputs());
      60           0 :     GrShaderVar sk_InvocationID("sk_InvocationID", kInt_GrSLType);
      61           0 :     this->declareGlobal(sk_InvocationID);
      62           0 :     SkASSERT(sk_InvocationID.getName() == SkString("sk_InvocationID"));
      63           0 :     if (this->getProgramBuilder()->shaderCaps()->mustImplementGSInvocationsWithLoop()) {
      64           0 :         SkString invokeFn;
      65           0 :         this->emitFunction(kVoid_GrSLType, "invoke", 0, nullptr, this->code().c_str(), &invokeFn);
      66           0 :         this->code().printf("for (sk_InvocationID = 0; sk_InvocationID < %i; ++sk_InvocationID) {"
      67             :                                 "%s();"
      68             :                                 "EndPrimitive();"
      69           0 :                             "}", fNumInvocations, invokeFn.c_str());
      70             :     } else {
      71           0 :         this->codePrependf("sk_InvocationID = gl_InvocationID;");
      72             :     }
      73           0 : }