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
16namespace SkSL {
17
18class CPPCodeGenerator : public GLSLCodeGenerator {
19public:
20 CPPCodeGenerator(const Context* context, const Program* program, ErrorReporter* errors,
21 String name, OutputStream* out);
22
23 bool generateCode() override;
24
25private:
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 String formatRuntimeValue(const Type& type, const Layout& layout, const String& cppCode,
71 std::vector<String>* formatArgs);
72
73 void writeVarInitializer(const Variable& var, const Expression& value) override;
74
75 void writeInputVars() override;
76
77 void writePrivateVars();
78
79 void writePrivateVarValues();
80
81 void writeCodeAppend(const String& code);
82
83 bool writeEmitCode(std::vector<const Variable*>& uniforms);
84
85 void writeSetData(std::vector<const Variable*>& uniforms);
86
87 void writeGetKey();
88
89 void writeOnTextureSampler();
90
91 void writeClone();
92
93 void writeDumpInfo();
94
95 void writeTest();
96
97 // If the returned C++ is included in the generated code, then the variable name stored in
98 // cppVar will refer to a valid SkString that matches the Expression. Successful returns leave
99 // the output buffer (and related state) unmodified.
100 //
101 // In the simplest cases, this will return "SkString {cppVar}(\"{e}\");", while more advanced
102 // cases will properly insert format arguments.
103 String convertSKSLExpressionToCPP(const Expression& e, const String& cppVar);
104
105 // Process accumulated sksl to split it into appended code sections, properly interleaved with
106 // the extra emit code blocks, based on statement/block locations and the inserted tokens
107 // from newExtraEmitCodeBlock(). It is necessary to split the sksl after the program has been
108 // fully walked since many elements redirect fOut to simultaneously build header sections and
109 // bodies that are then concatenated; due to this it is not possible to split the sksl emission
110 // on the fly.
111 void flushEmittedCode();
112
113 // Start a new extra emit code block for accumulating C++ code. This will insert a token into
114 // the sksl stream to mark the fence between previous complete sksl statements and where the
115 // C++ code added to the new block will be added to emitCode(). These tokens are removed by
116 // flushEmittedCode() as it consumes them before passing pure sksl to writeCodeAppend().
117 void newExtraEmitCodeBlock();
118
119 // Append CPP code to the current extra emit code block.
120 void addExtraEmitCodeLine(const String& toAppend);
121
122 int getChildFPIndex(const Variable& var) const;
123
124 String fName;
125 String fFullName;
126 SectionAndParameterHelper fSectionAndParameterHelper;
127 std::vector<String> fExtraEmitCodeBlocks;
128
129 std::vector<String> fFormatArgs;
130 // true if the sksl declared its main() function with a float2 parameter AND referenced that
131 // parameter in its body.
132 bool fAccessSampleCoordsDirectly = false;
133
134 // if true, we are writing a C++ expression instead of a GLSL expression
135 bool fCPPMode = false;
136 bool fInMain = false;
137
138 // if not null, we are accumulating SkSL for emitCode into fOut, which
139 // replaced the original buffer with a StringStream. The original buffer is
140 // stored here for restoration.
141 OutputStream* fCPPBuffer = nullptr;
142
143 typedef GLSLCodeGenerator INHERITED;
144};
145
146} // namespace SkSL
147
148#endif
149