1 /* 2 * Copyright 2016 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 #ifndef SKSL_INDEX 9 #define SKSL_INDEX 10 11 #include "SkSLContext.h" 12 #include "SkSLExpression.h" 13 #include "SkSLUtil.h" 14 15 namespace SkSL { 16 17 /** 18 * Given a type, returns the type that will result from extracting an array value from it. 19 */ 20 static const Type& index_type(const Context& context, const Type& type) { 21 if (type.kind() == Type::kMatrix_Kind) { 22 if (type.componentType() == *context.fFloat_Type) { 23 switch (type.rows()) { 24 case 2: return *context.fVec2_Type; 25 case 3: return *context.fVec3_Type; 26 case 4: return *context.fVec4_Type; 27 default: ASSERT(false); 28 } 29 } else { 30 ASSERT(type.componentType() == *context.fDouble_Type); 31 switch (type.rows()) { 32 case 2: return *context.fDVec2_Type; 33 case 3: return *context.fDVec3_Type; 34 case 4: return *context.fDVec4_Type; 35 default: ASSERT(false); 36 } 37 } 38 } 39 return type.componentType(); 40 } 41 42 /** 43 * An expression which extracts a value from an array or matrix, as in 'm[2]'. 44 */ 45 struct IndexExpression : public Expression { 46 IndexExpression(const Context& context, std::unique_ptr<Expression> base, 47 std::unique_ptr<Expression> index) 48 : INHERITED(base->fPosition, kIndex_Kind, index_type(context, base->fType)) 49 , fBase(std::move(base)) 50 , fIndex(std::move(index)) { 51 ASSERT(fIndex->fType == *context.fInt_Type || fIndex->fType == *context.fUInt_Type); 52 } 53 54 bool hasSideEffects() const override { 55 return fBase->hasSideEffects() || fIndex->hasSideEffects(); 56 } 57 58 String description() const override { 59 return fBase->description() + "[" + fIndex->description() + "]"; 60 } 61 62 std::unique_ptr<Expression> fBase; 63 std::unique_ptr<Expression> fIndex; 64 65 typedef Expression INHERITED; 66 }; 67 68 } // namespace 69 70 #endif 71
