1 /* 2 * Copyright 2017 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_CPPCODEGENERATOR 9 #define SKSL_CPPCODEGENERATOR 10 11 #include "src/sksl/SkSLGLSLCodeGenerator.h" 12 #include "src/sksl/SkSLSectionAndParameterHelper.h" 13 14 #include <set> 15 16 namespace SkSL { 17 18 class CPPCodeGenerator : public GLSLCodeGenerator { 19 public: 20 CPPCodeGenerator(const Context* context, const Program* program, ErrorReporter* errors, 21 String name, OutputStream* out); 22 23 bool generateCode() override; 24 25 private: 26 void writef(const char* s, va_list va) SKSL_PRINTF_LIKE(2, 0); 27 28 void writef(const char* s, ...) SKSL_PRINTF_LIKE(2, 3); 29 30 bool writeSection(const char* name, const char* prefix = ""); 31 32 void writeHeader() override; 33 34 bool usesPrecisionModifiers() const override; 35 36 String getTypeName(const Type& type) override; 37 38 void writeBinaryExpression(const BinaryExpression& b, Precedence parentPrecedence) override; 39 40 void writeIndexExpression(const IndexExpression& i) override; 41 42 void writeIntLiteral(const IntLiteral& i) override; 43 44 void writeSwizzle(const Swizzle& swizzle) override; 45 46 void writeFieldAccess(const FieldAccess& access) override; 47 48 void writeVariableReference(const VariableReference& ref) override; 49 50 String getSamplerHandle(const Variable& var); 51 52 void writeIfStatement(const IfStatement& s) override; 53 54 void writeReturnStatement(const ReturnStatement& s) override; 55 56 void writeSwitchStatement(const SwitchStatement& s) override; 57 58 void writeFunctionCall(const FunctionCall& c) override; 59 60 void writeFunction(const FunctionDefinition& f) override; 61 62 void writeSetting(const Setting& s) override; 63 64 void writeProgramElement(const ProgramElement& p) override; 65 66 void addUniform(const Variable& var); 67 68 // writes a printf escape that will be filled in at runtime by the given C++ expression string 69 void writeRuntimeValue(const Type& type, const Layout& layout, const String& cppCode); 70 71 void writeVarInitializer(const Variable& var, const Expression& value) override; 72 73 void writeInputVars() override; 74 75 void writePrivateVars(); 76 77 void writePrivateVarValues(); 78 79 void writeCodeAppend(const String& code); 80 81 bool writeEmitCode(std::vector<const Variable*>& uniforms); 82 83 void writeSetData(std::vector<const Variable*>& uniforms); 84 85 void writeGetKey(); 86 87 void writeOnTextureSampler(); 88 89 void writeClone(); 90 91 void writeTest(); 92 93 // If the returned C++ is included in the generated code, then the variable name stored in 94 // cppVar will refer to a valid SkString that matches the Expression. Successful returns leave 95 // the output buffer (and related state) unmodified. 96 // 97 // In the simplest cases, this will return "SkString {cppVar}(\"{e}\");", while more advanced 98 // cases will properly insert format arguments. 99 String convertSKSLExpressionToCPP(const Expression& e, const String& cppVar); 100 101 // Process accumulated sksl to split it into appended code sections, properly interleaved with 102 // the extra emit code blocks, based on statement/block locations and the inserted tokens 103 // from newExtraEmitCodeBlock(). It is necessary to split the sksl after the program has been 104 // fully walked since many elements redirect fOut to simultaneously build header sections and 105 // bodies that are then concatenated; due to this it is not possible to split the sksl emission 106 // on the fly. 107 void flushEmittedCode(); 108 109 // Start a new extra emit code block for accumulating C++ code. This will insert a token into 110 // the sksl stream to mark the fence between previous complete sksl statements and where the 111 // C++ code added to the new block will be added to emitCode(). These tokens are removed by 112 // flushEmittedCode() as it consumes them before passing pure sksl to writeCodeAppend(). 113 void newExtraEmitCodeBlock(); 114 115 // Append CPP code to the current extra emit code block. 116 void addExtraEmitCodeLine(const String& toAppend); 117 118 int getChildFPIndex(const Variable& var) const; 119 120 String fName; 121 String fFullName; 122 SectionAndParameterHelper fSectionAndParameterHelper; 123 std::vector<String> fExtraEmitCodeBlocks; 124 125 std::vector<String> fFormatArgs; 126 std::set<int> fWrittenTransformedCoords; 127 // if true, we are writing a C++ expression instead of a GLSL expression 128 bool fCPPMode = false; 129 bool fInMain = false; 130 131 // if not null, we are accumulating SkSL for emitCode into fOut, which 132 // replaced the original buffer with a StringStream. The original buffer is 133 // stored here for restoration. 134 OutputStream* fCPPBuffer = nullptr; 135 136 typedef GLSLCodeGenerator INHERITED; 137 }; 138 139 } 140 141 #endif 142