1/**************************************************************************/
2/* shader_preprocessor.h */
3/**************************************************************************/
4/* This file is part of: */
5/* GODOT ENGINE */
6/* https://godotengine.org */
7/**************************************************************************/
8/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
9/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
10/* */
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12/* a copy of this software and associated documentation files (the */
13/* "Software"), to deal in the Software without restriction, including */
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15/* distribute, sublicense, and/or sell copies of the Software, and to */
16/* permit persons to whom the Software is furnished to do so, subject to */
17/* the following conditions: */
18/* */
19/* The above copyright notice and this permission notice shall be */
20/* included in all copies or substantial portions of the Software. */
21/* */
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28/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
29/**************************************************************************/
30
31#ifndef SHADER_PREPROCESSOR_H
32#define SHADER_PREPROCESSOR_H
33
34#include "core/string/ustring.h"
35#include "core/templates/list.h"
36#include "core/templates/local_vector.h"
37#include "core/templates/rb_map.h"
38#include "core/templates/rb_set.h"
39#include "core/typedefs.h"
40
41#include "core/io/resource_loader.h"
42#include "core/object/script_language.h"
43#include "core/os/os.h"
44#include "scene/resources/shader.h"
45#include "scene/resources/shader_include.h"
46
47class ShaderPreprocessor {
48public:
49 enum CompletionType {
50 COMPLETION_TYPE_NONE,
51 COMPLETION_TYPE_DIRECTIVE,
52 COMPLETION_TYPE_PRAGMA_DIRECTIVE,
53 COMPLETION_TYPE_PRAGMA,
54 COMPLETION_TYPE_CONDITION,
55 COMPLETION_TYPE_INCLUDE_PATH,
56 };
57
58 struct FilePosition {
59 String file;
60 int line = 0;
61 };
62
63 struct Region {
64 String file;
65 int from_line = -1;
66 int to_line = -1;
67 bool enabled = false;
68 Region *parent = nullptr;
69 };
70
71private:
72 struct Token {
73 char32_t text;
74 int line;
75
76 Token();
77 Token(char32_t p_text, int p_line);
78 };
79
80 // The real preprocessor that understands basic shader and preprocessor language syntax.
81 class Tokenizer {
82 public:
83 String code;
84 int line;
85 int index;
86 int size;
87 LocalVector<Token> generated;
88
89 private:
90 void add_generated(const Token &p_t);
91 char32_t next();
92
93 public:
94 int get_line() const;
95 int get_index() const;
96 char32_t peek();
97 int consume_line_continuations(int p_offset);
98
99 void get_and_clear_generated(LocalVector<char32_t> *r_out);
100 void backtrack(char32_t p_what);
101 LocalVector<Token> advance(char32_t p_what);
102 void skip_whitespace();
103 bool consume_empty_line();
104 String get_identifier(bool *r_is_cursor = nullptr, bool p_started = false);
105 String peek_identifier();
106 Token get_token();
107
108 Tokenizer(const String &p_code);
109 };
110
111 class CommentRemover {
112 private:
113 LocalVector<char32_t> stripped;
114 String code;
115 int index;
116 int line;
117 int comment_line_open;
118 int comments_open;
119 int strings_open;
120
121 public:
122 String get_error() const;
123 int get_error_line() const;
124 char32_t peek() const;
125
126 bool advance(char32_t p_what);
127 String strip();
128
129 CommentRemover(const String &p_code);
130 };
131
132 struct Define {
133 Vector<String> arguments;
134 String body;
135 };
136
137 struct Branch {
138 Vector<bool> conditions;
139 Branch *parent = nullptr;
140 bool else_defined = false;
141
142 Branch() {}
143
144 Branch(bool p_condition, Branch *p_parent) :
145 parent(p_parent) {
146 conditions.push_back(p_condition);
147 }
148 };
149
150 struct State {
151 RBMap<String, Define *> defines;
152 List<Branch> branches;
153 Branch *current_branch = nullptr;
154 int condition_depth = 0;
155 RBSet<String> includes;
156 List<uint64_t> cyclic_include_hashes; // Holds code hash of includes.
157 int include_depth = 0;
158 String current_filename;
159 String current_shader_type;
160 String error;
161 List<FilePosition> include_positions;
162 bool save_regions = false;
163 RBMap<String, List<Region>> regions;
164 Region *previous_region = nullptr;
165 bool disabled = false;
166 CompletionType completion_type = COMPLETION_TYPE_NONE;
167 HashSet<Ref<ShaderInclude>> shader_includes;
168 };
169
170private:
171 LocalVector<char32_t> output;
172 State *state = nullptr;
173
174private:
175 static bool is_char_word(char32_t p_char);
176 static bool is_char_space(char32_t p_char);
177 static bool is_char_end(char32_t p_char);
178 static String vector_to_string(const LocalVector<char32_t> &p_v, int p_start = 0, int p_end = -1);
179 static String tokens_to_string(const LocalVector<Token> &p_tokens);
180
181 void _set_expected_error(const String &p_what, int p_line) {
182 set_error(vformat(RTR("Expected a '%s'."), p_what), p_line);
183 }
184
185 void _set_unexpected_token_error(const String &p_what, int p_line) {
186 set_error(vformat(RTR("Unexpected token: '%s'."), p_what), p_line);
187 }
188
189 void process_directive(Tokenizer *p_tokenizer);
190 void process_define(Tokenizer *p_tokenizer);
191 void process_elif(Tokenizer *p_tokenizer);
192 void process_else(Tokenizer *p_tokenizer);
193 void process_endif(Tokenizer *p_tokenizer);
194 void process_if(Tokenizer *p_tokenizer);
195 void process_ifdef(Tokenizer *p_tokenizer);
196 void process_ifndef(Tokenizer *p_tokenizer);
197 void process_include(Tokenizer *p_tokenizer);
198 void process_pragma(Tokenizer *p_tokenizer);
199 void process_undef(Tokenizer *p_tokenizer);
200
201 void add_region(int p_line, bool p_enabled, Region *p_parent_region);
202 void start_branch_condition(Tokenizer *p_tokenizer, bool p_success, bool p_continue = false);
203
204 Error expand_condition(const String &p_string, int p_line, String &r_result);
205 void expand_output_macros(int p_start, int p_line);
206 Error expand_macros(const String &p_string, int p_line, String &r_result);
207 bool expand_macros_once(const String &p_line, int p_line_number, const RBMap<String, Define *>::Element *p_define_pair, String &r_expanded);
208 bool find_match(const String &p_string, const String &p_value, int &r_index, int &r_index_start);
209 void concatenate_macro_body(String &r_body);
210
211 String next_directive(Tokenizer *p_tokenizer, const Vector<String> &p_directives);
212 void add_to_output(const String &p_str);
213 void set_error(const String &p_error, int p_line);
214
215 static Define *create_define(const String &p_body);
216
217 void clear_state();
218
219 Error preprocess(State *p_state, const String &p_code, String &r_result);
220
221public:
222 typedef void (*IncludeCompletionFunction)(List<ScriptLanguage::CodeCompletionOption> *);
223
224 Error preprocess(const String &p_code, const String &p_filename, String &r_result, String *r_error_text = nullptr, List<FilePosition> *r_error_position = nullptr, List<Region> *r_regions = nullptr, HashSet<Ref<ShaderInclude>> *r_includes = nullptr, List<ScriptLanguage::CodeCompletionOption> *r_completion_options = nullptr, List<ScriptLanguage::CodeCompletionOption> *r_completion_defines = nullptr, IncludeCompletionFunction p_include_completion_func = nullptr);
225
226 static void get_keyword_list(List<String> *r_keywords, bool p_include_shader_keywords, bool p_ignore_context_keywords = false);
227 static void get_pragma_list(List<String> *r_pragmas);
228
229 ShaderPreprocessor();
230 ~ShaderPreprocessor();
231};
232
233#endif // SHADER_PREPROCESSOR_H
234