1// 2// Copyright (c) 2002-2012 The ANGLE Project Authors. All rights reserved. 3// Use of this source code is governed by a BSD-style license that can be 4// found in the LICENSE file. 5// 6 7#include "compiler/translator/VersionGLSL.h" 8 9static const int GLSL_VERSION_110 = 110; 10static const int GLSL_VERSION_120 = 120; 11 12// We need to scan for the following: 13// 1. "invariant" keyword: This can occur in both - vertex and fragment shaders 14// but only at the global scope. 15// 2. "gl_PointCoord" built-in variable: This can only occur in fragment shader 16// but inside any scope. 17// 3. Call to a matrix constructor with another matrix as argument. 18// (These constructors were reserved in GLSL version 1.10.) 19// 4. Arrays as "out" function parameters. 20// GLSL spec section 6.1.1: "When calling a function, expressions that do 21// not evaluate to l-values cannot be passed to parameters declared as 22// out or inout." 23// GLSL 1.1 section 5.8: "Other binary or unary expressions, 24// non-dereferenced arrays, function names, swizzles with repeated fields, 25// and constants cannot be l-values." 26// GLSL 1.2 relaxed the restriction on arrays, section 5.8: "Variables that 27// are built-in types, entire structures or arrays... are all l-values." 28// 29// TODO(alokp): The following two cases of invariant decalaration get lost 30// during parsing - they do not get carried over to the intermediate tree. 31// Handle these cases: 32// 1. When a pragma is used to force all output variables to be invariant: 33// - #pragma STDGL invariant(all) 34// 2. When a previously decalared or built-in variable is marked invariant: 35// - invariant gl_Position; 36// - varying vec3 color; invariant color; 37// 38TVersionGLSL::TVersionGLSL(sh::GLenum type) 39 : mVersion(GLSL_VERSION_110) 40{ 41} 42 43void TVersionGLSL::visitSymbol(TIntermSymbol *node) 44{ 45 if (node->getSymbol() == "gl_PointCoord") 46 updateVersion(GLSL_VERSION_120); 47} 48 49bool TVersionGLSL::visitAggregate(Visit, TIntermAggregate *node) 50{ 51 bool visitChildren = true; 52 53 switch (node->getOp()) 54 { 55 case EOpSequence: 56 // We need to visit sequence children to get to global or inner scope. 57 visitChildren = true; 58 break; 59 case EOpDeclaration: 60 { 61 const TIntermSequence &sequence = *(node->getSequence()); 62 TQualifier qualifier = sequence.front()->getAsTyped()->getQualifier(); 63 if ((qualifier == EvqInvariantVaryingIn) || 64 (qualifier == EvqInvariantVaryingOut)) 65 { 66 updateVersion(GLSL_VERSION_120); 67 } 68 break; 69 } 70 case EOpInvariantDeclaration: 71 updateVersion(GLSL_VERSION_120); 72 break; 73 case EOpParameters: 74 { 75 const TIntermSequence ¶ms = *(node->getSequence()); 76 for (TIntermSequence::const_iterator iter = params.begin(); 77 iter != params.end(); ++iter) 78 { 79 const TIntermTyped *param = (*iter)->getAsTyped(); 80 if (param->isArray()) 81 { 82 TQualifier qualifier = param->getQualifier(); 83 if ((qualifier == EvqOut) || (qualifier == EvqInOut)) 84 { 85 updateVersion(GLSL_VERSION_120); 86 break; 87 } 88 } 89 } 90 // Fully processed. No need to visit children. 91 visitChildren = false; 92 break; 93 } 94 case EOpConstructMat2: 95 case EOpConstructMat3: 96 case EOpConstructMat4: 97 { 98 const TIntermSequence &sequence = *(node->getSequence()); 99 if (sequence.size() == 1) 100 { 101 TIntermTyped *typed = sequence.front()->getAsTyped(); 102 if (typed && typed->isMatrix()) 103 { 104 updateVersion(GLSL_VERSION_120); 105 } 106 } 107 break; 108 } 109 default: 110 break; 111 } 112 113 return visitChildren; 114} 115 116void TVersionGLSL::updateVersion(int version) 117{ 118 mVersion = std::max(version, mVersion); 119} 120 121