ethannicholas | b3058bd | 2016-07-01 08:22:01 -0700 | [diff] [blame^] | 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 "SkSLExpression.h" |
| 12 | #include "SkSLUtil.h" |
| 13 | |
| 14 | namespace SkSL { |
| 15 | |
| 16 | /** |
| 17 | * Given a type, returns the type that will result from extracting an array value from it. |
| 18 | */ |
| 19 | static std::shared_ptr<Type> index_type(const Type& type) { |
| 20 | if (type.kind() == Type::kMatrix_Kind) { |
| 21 | if (type.componentType() == kFloat_Type) { |
| 22 | switch (type.columns()) { |
| 23 | case 2: return kVec2_Type; |
| 24 | case 3: return kVec3_Type; |
| 25 | case 4: return kVec4_Type; |
| 26 | default: ASSERT(false); |
| 27 | } |
| 28 | } else { |
| 29 | ASSERT(type.componentType() == kDouble_Type); |
| 30 | switch (type.columns()) { |
| 31 | case 2: return kDVec2_Type; |
| 32 | case 3: return kDVec3_Type; |
| 33 | case 4: return kDVec4_Type; |
| 34 | default: ASSERT(false); |
| 35 | } |
| 36 | } |
| 37 | } |
| 38 | return type.componentType(); |
| 39 | } |
| 40 | |
| 41 | /** |
| 42 | * An expression which extracts a value from an array or matrix, as in 'm[2]'. |
| 43 | */ |
| 44 | struct IndexExpression : public Expression { |
| 45 | IndexExpression(std::unique_ptr<Expression> base, std::unique_ptr<Expression> index) |
| 46 | : INHERITED(base->fPosition, kIndex_Kind, index_type(*base->fType)) |
| 47 | , fBase(std::move(base)) |
| 48 | , fIndex(std::move(index)) { |
| 49 | ASSERT(fIndex->fType == kInt_Type); |
| 50 | } |
| 51 | |
| 52 | std::string description() const override { |
| 53 | return fBase->description() + "[" + fIndex->description() + "]"; |
| 54 | } |
| 55 | |
| 56 | const std::unique_ptr<Expression> fBase; |
| 57 | const std::unique_ptr<Expression> fIndex; |
| 58 | |
| 59 | typedef Expression INHERITED; |
| 60 | }; |
| 61 | |
| 62 | } // namespace |
| 63 | |
| 64 | #endif |