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
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