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 "GrGLSLVertexShaderBuilder.h" 9 #include "glsl/GrGLSLProgramBuilder.h" 10 #include "glsl/GrGLSLUniformHandler.h" 11 #include "glsl/GrGLSLVarying.h" 12 13 GrGLSLVertexBuilder::GrGLSLVertexBuilder(GrGLSLProgramBuilder* program) 14 : INHERITED(program) 15 , fRtAdjustName(nullptr) { 16 } 17 18 void GrGLSLVertexBuilder::transformToNormalizedDeviceSpace(const GrShaderVar& posVar) { 19 SkASSERT(!fRtAdjustName); 20 21 // setup RT Uniform 22 fProgramBuilder->addRTAdjustmentUniform(kHigh_GrSLPrecision, 23 fProgramBuilder->rtAdjustment(), 24 &fRtAdjustName); 25 if (this->getProgramBuilder()->desc().header().fSnapVerticesToPixelCenters) { 26 if (kVec3f_GrSLType == posVar.getType()) { 27 const char* p = posVar.c_str(); 28 this->codeAppendf("{vec2 _posTmp = vec2(%s.x/%s.z, %s.y/%s.z);", p, p, p, p); 29 } else { 30 SkASSERT(kVec2f_GrSLType == posVar.getType()); 31 this->codeAppendf("{vec2 _posTmp = %s;", posVar.c_str()); 32 } 33 this->codeAppendf("_posTmp = floor(_posTmp) + vec2(0.5, 0.5);" 34 "gl_Position = vec4(_posTmp.x * %s.x + %s.y," 35 "_posTmp.y * %s.z + %s.w, 0, 1);}", 36 fRtAdjustName, fRtAdjustName, fRtAdjustName, fRtAdjustName); 37 } else if (kVec3f_GrSLType == posVar.getType()) { 38 this->codeAppendf("gl_Position = vec4(dot(%s.xz, %s.xy), dot(%s.yz, %s.zw), 0, %s.z);", 39 posVar.c_str(), fRtAdjustName, 40 posVar.c_str(), fRtAdjustName, 41 posVar.c_str()); 42 } else { 43 SkASSERT(kVec2f_GrSLType == posVar.getType()); 44 this->codeAppendf("gl_Position = vec4(%s.x * %s.x + %s.y, %s.y * %s.z + %s.w, 0, 1);", 45 posVar.c_str(), fRtAdjustName, fRtAdjustName, 46 posVar.c_str(), fRtAdjustName, fRtAdjustName); 47 } 48 // We could have the GrGeometryProcessor do this, but its just easier to have it performed 49 // here. If we ever need to set variable pointsize, then we can reinvestigate 50 this->codeAppend("gl_PointSize = 1.0;"); 51 } 52 53 void GrGLSLVertexBuilder::onFinalize() { 54 fProgramBuilder->varyingHandler()->getVertexDecls(&this->inputs(), &this->outputs()); 55 } 56 57
