1 | /* |
2 | * Copyright © 2008 Kristian Høgsberg |
3 | * |
4 | * Permission is hereby granted, free of charge, to any person obtaining |
5 | * a copy of this software and associated documentation files (the |
6 | * "Software"), to deal in the Software without restriction, including |
7 | * without limitation the rights to use, copy, modify, merge, publish, |
8 | * distribute, sublicense, and/or sell copies of the Software, and to |
9 | * permit persons to whom the Software is furnished to do so, subject to |
10 | * the following conditions: |
11 | * |
12 | * The above copyright notice and this permission notice (including the |
13 | * next paragraph) shall be included in all copies or substantial |
14 | * portions of the Software. |
15 | * |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
17 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
18 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
19 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
20 | * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
21 | * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
22 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
23 | * SOFTWARE. |
24 | */ |
25 | |
26 | /** \file wayland-util.h |
27 | * |
28 | * \brief Utility classes, functions, and macros. |
29 | */ |
30 | |
31 | #ifndef WAYLAND_UTIL_H |
32 | #define WAYLAND_UTIL_H |
33 | |
34 | #include <math.h> |
35 | #include <stddef.h> |
36 | #include <inttypes.h> |
37 | #include <stdarg.h> |
38 | |
39 | #ifdef __cplusplus |
40 | extern "C" { |
41 | #endif |
42 | |
43 | /** Visibility attribute */ |
44 | #if defined(__GNUC__) && __GNUC__ >= 4 |
45 | #define WL_EXPORT __attribute__ ((visibility("default"))) |
46 | #else |
47 | #define WL_EXPORT |
48 | #endif |
49 | |
50 | /** Deprecated attribute */ |
51 | #if defined(__GNUC__) && __GNUC__ >= 4 |
52 | #define WL_DEPRECATED __attribute__ ((deprecated)) |
53 | #else |
54 | #define WL_DEPRECATED |
55 | #endif |
56 | |
57 | /** |
58 | * Printf-style argument attribute |
59 | * |
60 | * \param x Ordinality of the format string argument |
61 | * \param y Ordinality of the argument to check against the format string |
62 | * |
63 | * \sa https://gcc.gnu.org/onlinedocs/gcc-3.2.1/gcc/Function-Attributes.html |
64 | */ |
65 | #if defined(__GNUC__) && __GNUC__ >= 4 |
66 | #define WL_PRINTF(x, y) __attribute__((__format__(__printf__, x, y))) |
67 | #else |
68 | #define WL_PRINTF(x, y) |
69 | #endif |
70 | |
71 | /** \class wl_object |
72 | * |
73 | * \brief A protocol object. |
74 | * |
75 | * A `wl_object` is an opaque struct identifying the protocol object |
76 | * underlying a `wl_proxy` or `wl_resource`. |
77 | * |
78 | * \note Functions accessing a `wl_object` are not normally used by client code. |
79 | * Clients should normally use the higher level interface generated by the |
80 | * scanner to interact with compositor objects. |
81 | * |
82 | */ |
83 | struct wl_object; |
84 | |
85 | /** |
86 | * Protocol message signature |
87 | * |
88 | * A wl_message describes the signature of an actual protocol message, such as a |
89 | * request or event, that adheres to the Wayland protocol wire format. The |
90 | * protocol implementation uses a wl_message within its demarshal machinery for |
91 | * decoding messages between a compositor and its clients. In a sense, a |
92 | * wl_message is to a protocol message like a class is to an object. |
93 | * |
94 | * The `name` of a wl_message is the name of the corresponding protocol message. |
95 | * |
96 | * The `signature` is an ordered list of symbols representing the data types |
97 | * of message arguments and, optionally, a protocol version and indicators for |
98 | * nullability. A leading integer in the `signature` indicates the _since_ |
99 | * version of the protocol message. A `?` preceding a data type symbol indicates |
100 | * that the following argument type is nullable. While it is a protocol violation |
101 | * to send messages with non-nullable arguments set to `NULL`, event handlers in |
102 | * clients might still get called with non-nullable object arguments set to |
103 | * `NULL`. This can happen when the client destroyed the object being used as |
104 | * argument on its side and an event referencing that object was sent before the |
105 | * server knew about its destruction. As this race cannot be prevented, clients |
106 | * should - as a general rule - program their event handlers such that they can |
107 | * handle object arguments declared non-nullable being `NULL` gracefully. |
108 | * |
109 | * When no arguments accompany a message, `signature` is an empty string. |
110 | * |
111 | * Symbols: |
112 | * |
113 | * * `i`: int |
114 | * * `u`: uint |
115 | * * `f`: fixed |
116 | * * `s`: string |
117 | * * `o`: object |
118 | * * `n`: new_id |
119 | * * `a`: array |
120 | * * `h`: fd |
121 | * * `?`: following argument is nullable |
122 | * |
123 | * While demarshaling primitive arguments is straightforward, when demarshaling |
124 | * messages containing `object` or `new_id` arguments, the protocol |
125 | * implementation often must determine the type of the object. The `types` of a |
126 | * wl_message is an array of wl_interface references that correspond to `o` and |
127 | * `n` arguments in `signature`, with `NULL` placeholders for arguments with |
128 | * non-object types. |
129 | * |
130 | * Consider the protocol event wl_display `delete_id` that has a single `uint` |
131 | * argument. The wl_message is: |
132 | * |
133 | * \code |
134 | * { "delete_id", "u", [NULL] } |
135 | * \endcode |
136 | * |
137 | * Here, the message `name` is `"delete_id"`, the `signature` is `"u"`, and the |
138 | * argument `types` is `[NULL]`, indicating that the `uint` argument has no |
139 | * corresponding wl_interface since it is a primitive argument. |
140 | * |
141 | * In contrast, consider a `wl_foo` interface supporting protocol request `bar` |
142 | * that has existed since version 2, and has two arguments: a `uint` and an |
143 | * object of type `wl_baz_interface` that may be `NULL`. Such a `wl_message` |
144 | * might be: |
145 | * |
146 | * \code |
147 | * { "bar", "2u?o", [NULL, &wl_baz_interface] } |
148 | * \endcode |
149 | * |
150 | * Here, the message `name` is `"bar"`, and the `signature` is `"2u?o"`. Notice |
151 | * how the `2` indicates the protocol version, the `u` indicates the first |
152 | * argument type is `uint`, and the `?o` indicates that the second argument |
153 | * is an object that may be `NULL`. Lastly, the argument `types` array indicates |
154 | * that no wl_interface corresponds to the first argument, while the type |
155 | * `wl_baz_interface` corresponds to the second argument. |
156 | * |
157 | * \sa wl_argument |
158 | * \sa wl_interface |
159 | * \sa <a href="https://wayland.freedesktop.org/docs/html/ch04.html#sect-Protocol-Wire-Format">Wire Format</a> |
160 | */ |
161 | struct wl_message { |
162 | /** Message name */ |
163 | const char *name; |
164 | /** Message signature */ |
165 | const char *signature; |
166 | /** Object argument interfaces */ |
167 | const struct wl_interface **types; |
168 | }; |
169 | |
170 | /** |
171 | * Protocol object interface |
172 | * |
173 | * A wl_interface describes the API of a protocol object defined in the Wayland |
174 | * protocol specification. The protocol implementation uses a wl_interface |
175 | * within its marshalling machinery for encoding client requests. |
176 | * |
177 | * The `name` of a wl_interface is the name of the corresponding protocol |
178 | * interface, and `version` represents the version of the interface. The members |
179 | * `method_count` and `event_count` represent the number of `methods` (requests) |
180 | * and `events` in the respective wl_message members. |
181 | * |
182 | * For example, consider a protocol interface `foo`, marked as version `1`, with |
183 | * two requests and one event. |
184 | * |
185 | * \code |
186 | * <interface name="foo" version="1"> |
187 | * <request name="a"></request> |
188 | * <request name="b"></request> |
189 | * <event name="c"></event> |
190 | * </interface> |
191 | * \endcode |
192 | * |
193 | * Given two wl_message arrays `foo_requests` and `foo_events`, a wl_interface |
194 | * for `foo` might be: |
195 | * |
196 | * \code |
197 | * struct wl_interface foo_interface = { |
198 | * "foo", 1, |
199 | * 2, foo_requests, |
200 | * 1, foo_events |
201 | * }; |
202 | * \endcode |
203 | * |
204 | * \note The server side of the protocol may define interface <em>implementation |
205 | * types</em> that incorporate the term `interface` in their name. Take |
206 | * care to not confuse these server-side `struct`s with a wl_interface |
207 | * variable whose name also ends in `interface`. For example, while the |
208 | * server may define a type `struct wl_foo_interface`, the client may |
209 | * define a `struct wl_interface wl_foo_interface`. |
210 | * |
211 | * \sa wl_message |
212 | * \sa wl_proxy |
213 | * \sa <a href="https://wayland.freedesktop.org/docs/html/ch04.html#sect-Protocol-Interfaces">Interfaces</a> |
214 | * \sa <a href="https://wayland.freedesktop.org/docs/html/ch04.html#sect-Protocol-Versioning">Versioning</a> |
215 | */ |
216 | struct wl_interface { |
217 | /** Interface name */ |
218 | const char *name; |
219 | /** Interface version */ |
220 | int version; |
221 | /** Number of methods (requests) */ |
222 | int method_count; |
223 | /** Method (request) signatures */ |
224 | const struct wl_message *methods; |
225 | /** Number of events */ |
226 | int event_count; |
227 | /** Event signatures */ |
228 | const struct wl_message *events; |
229 | }; |
230 | |
231 | /** \class wl_list |
232 | * |
233 | * \brief Doubly-linked list |
234 | * |
235 | * On its own, an instance of `struct wl_list` represents the sentinel head of |
236 | * a doubly-linked list, and must be initialized using wl_list_init(). |
237 | * When empty, the list head's `next` and `prev` members point to the list head |
238 | * itself, otherwise `next` references the first element in the list, and `prev` |
239 | * refers to the last element in the list. |
240 | * |
241 | * Use the `struct wl_list` type to represent both the list head and the links |
242 | * between elements within the list. Use wl_list_empty() to determine if the |
243 | * list is empty in O(1). |
244 | * |
245 | * All elements in the list must be of the same type. The element type must have |
246 | * a `struct wl_list` member, often named `link` by convention. Prior to |
247 | * insertion, there is no need to initialize an element's `link` - invoking |
248 | * wl_list_init() on an individual list element's `struct wl_list` member is |
249 | * unnecessary if the very next operation is wl_list_insert(). However, a |
250 | * common idiom is to initialize an element's `link` prior to removal - ensure |
251 | * safety by invoking wl_list_init() before wl_list_remove(). |
252 | * |
253 | * Consider a list reference `struct wl_list foo_list`, an element type as |
254 | * `struct element`, and an element's link member as `struct wl_list link`. |
255 | * |
256 | * The following code initializes a list and adds three elements to it. |
257 | * |
258 | * \code |
259 | * struct wl_list foo_list; |
260 | * |
261 | * struct element { |
262 | * int foo; |
263 | * struct wl_list link; |
264 | * }; |
265 | * struct element e1, e2, e3; |
266 | * |
267 | * wl_list_init(&foo_list); |
268 | * wl_list_insert(&foo_list, &e1.link); // e1 is the first element |
269 | * wl_list_insert(&foo_list, &e2.link); // e2 is now the first element |
270 | * wl_list_insert(&e2.link, &e3.link); // insert e3 after e2 |
271 | * \endcode |
272 | * |
273 | * The list now looks like <em>[e2, e3, e1]</em>. |
274 | * |
275 | * The `wl_list` API provides some iterator macros. For example, to iterate |
276 | * a list in ascending order: |
277 | * |
278 | * \code |
279 | * struct element *e; |
280 | * wl_list_for_each(e, foo_list, link) { |
281 | * do_something_with_element(e); |
282 | * } |
283 | * \endcode |
284 | * |
285 | * See the documentation of each iterator for details. |
286 | * \sa http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/include/linux/list.h |
287 | */ |
288 | struct wl_list { |
289 | /** Previous list element */ |
290 | struct wl_list *prev; |
291 | /** Next list element */ |
292 | struct wl_list *next; |
293 | }; |
294 | |
295 | /** |
296 | * Initializes the list. |
297 | * |
298 | * \param list List to initialize |
299 | * |
300 | * \memberof wl_list |
301 | */ |
302 | void |
303 | wl_list_init(struct wl_list *list); |
304 | |
305 | /** |
306 | * Inserts an element into the list, after the element represented by \p list. |
307 | * When \p list is a reference to the list itself (the head), set the containing |
308 | * struct of \p elm as the first element in the list. |
309 | * |
310 | * \note If \p elm is already part of a list, inserting it again will lead to |
311 | * list corruption. |
312 | * |
313 | * \param list List element after which the new element is inserted |
314 | * \param elm Link of the containing struct to insert into the list |
315 | * |
316 | * \memberof wl_list |
317 | */ |
318 | void |
319 | wl_list_insert(struct wl_list *list, struct wl_list *elm); |
320 | |
321 | /** |
322 | * Removes an element from the list. |
323 | * |
324 | * \note This operation leaves \p elm in an invalid state. |
325 | * |
326 | * \param elm Link of the containing struct to remove from the list |
327 | * |
328 | * \memberof wl_list |
329 | */ |
330 | void |
331 | wl_list_remove(struct wl_list *elm); |
332 | |
333 | /** |
334 | * Determines the length of the list. |
335 | * |
336 | * \note This is an O(n) operation. |
337 | * |
338 | * \param list List whose length is to be determined |
339 | * |
340 | * \return Number of elements in the list |
341 | * |
342 | * \memberof wl_list |
343 | */ |
344 | int |
345 | wl_list_length(const struct wl_list *list); |
346 | |
347 | /** |
348 | * Determines if the list is empty. |
349 | * |
350 | * \param list List whose emptiness is to be determined |
351 | * |
352 | * \return 1 if empty, or 0 if not empty |
353 | * |
354 | * \memberof wl_list |
355 | */ |
356 | int |
357 | wl_list_empty(const struct wl_list *list); |
358 | |
359 | /** |
360 | * Inserts all of the elements of one list into another, after the element |
361 | * represented by \p list. |
362 | * |
363 | * \note This leaves \p other in an invalid state. |
364 | * |
365 | * \param list List element after which the other list elements will be inserted |
366 | * \param other List of elements to insert |
367 | * |
368 | * \memberof wl_list |
369 | */ |
370 | void |
371 | wl_list_insert_list(struct wl_list *list, struct wl_list *other); |
372 | |
373 | /** |
374 | * Retrieves a pointer to a containing struct, given a member name. |
375 | * |
376 | * This macro allows "conversion" from a pointer to a member to its containing |
377 | * struct. This is useful if you have a contained item like a wl_list, |
378 | * wl_listener, or wl_signal, provided via a callback or other means, and would |
379 | * like to retrieve the struct that contains it. |
380 | * |
381 | * To demonstrate, the following example retrieves a pointer to |
382 | * `example_container` given only its `destroy_listener` member: |
383 | * |
384 | * \code |
385 | * struct example_container { |
386 | * struct wl_listener destroy_listener; |
387 | * // other members... |
388 | * }; |
389 | * |
390 | * void example_container_destroy(struct wl_listener *listener, void *data) |
391 | * { |
392 | * struct example_container *ctr; |
393 | * |
394 | * ctr = wl_container_of(listener, ctr, destroy_listener); |
395 | * // destroy ctr... |
396 | * } |
397 | * \endcode |
398 | * |
399 | * \note `sample` need not be a valid pointer. A null or uninitialised pointer |
400 | * is sufficient. |
401 | * |
402 | * \param ptr Valid pointer to the contained member |
403 | * \param sample Pointer to a struct whose type contains \p ptr |
404 | * \param member Named location of \p ptr within the \p sample type |
405 | * |
406 | * \return The container for the specified pointer |
407 | */ |
408 | #define wl_container_of(ptr, sample, member) \ |
409 | (__typeof__(sample))((char *)(ptr) - \ |
410 | offsetof(__typeof__(*sample), member)) |
411 | |
412 | /** |
413 | * Iterates over a list. |
414 | * |
415 | * This macro expresses a for-each iterator for wl_list. Given a list and |
416 | * wl_list link member name (often named `link` by convention), this macro |
417 | * assigns each element in the list to \p pos, which can then be referenced in |
418 | * a trailing code block. For example, given a wl_list of `struct message` |
419 | * elements: |
420 | * |
421 | * \code |
422 | * struct message { |
423 | * char *contents; |
424 | * wl_list link; |
425 | * }; |
426 | * |
427 | * struct wl_list *message_list; |
428 | * // Assume message_list now "contains" many messages |
429 | * |
430 | * struct message *m; |
431 | * wl_list_for_each(m, message_list, link) { |
432 | * do_something_with_message(m); |
433 | * } |
434 | * \endcode |
435 | * |
436 | * \param pos Cursor that each list element will be assigned to |
437 | * \param head Head of the list to iterate over |
438 | * \param member Name of the link member within the element struct |
439 | * |
440 | * \relates wl_list |
441 | */ |
442 | #define wl_list_for_each(pos, head, member) \ |
443 | for (pos = wl_container_of((head)->next, pos, member); \ |
444 | &pos->member != (head); \ |
445 | pos = wl_container_of(pos->member.next, pos, member)) |
446 | |
447 | /** |
448 | * Iterates over a list, safe against removal of the list element. |
449 | * |
450 | * \note Only removal of the current element, \p pos, is safe. Removing |
451 | * any other element during traversal may lead to a loop malfunction. |
452 | * |
453 | * \sa wl_list_for_each() |
454 | * |
455 | * \param pos Cursor that each list element will be assigned to |
456 | * \param tmp Temporary pointer of the same type as \p pos |
457 | * \param head Head of the list to iterate over |
458 | * \param member Name of the link member within the element struct |
459 | * |
460 | * \relates wl_list |
461 | */ |
462 | #define wl_list_for_each_safe(pos, tmp, head, member) \ |
463 | for (pos = wl_container_of((head)->next, pos, member), \ |
464 | tmp = wl_container_of((pos)->member.next, tmp, member); \ |
465 | &pos->member != (head); \ |
466 | pos = tmp, \ |
467 | tmp = wl_container_of(pos->member.next, tmp, member)) |
468 | |
469 | /** |
470 | * Iterates backwards over a list. |
471 | * |
472 | * \sa wl_list_for_each() |
473 | * |
474 | * \param pos Cursor that each list element will be assigned to |
475 | * \param head Head of the list to iterate over |
476 | * \param member Name of the link member within the element struct |
477 | * |
478 | * \relates wl_list |
479 | */ |
480 | #define wl_list_for_each_reverse(pos, head, member) \ |
481 | for (pos = wl_container_of((head)->prev, pos, member); \ |
482 | &pos->member != (head); \ |
483 | pos = wl_container_of(pos->member.prev, pos, member)) |
484 | |
485 | /** |
486 | * Iterates backwards over a list, safe against removal of the list element. |
487 | * |
488 | * \note Only removal of the current element, \p pos, is safe. Removing |
489 | * any other element during traversal may lead to a loop malfunction. |
490 | * |
491 | * \sa wl_list_for_each() |
492 | * |
493 | * \param pos Cursor that each list element will be assigned to |
494 | * \param tmp Temporary pointer of the same type as \p pos |
495 | * \param head Head of the list to iterate over |
496 | * \param member Name of the link member within the element struct |
497 | * |
498 | * \relates wl_list |
499 | */ |
500 | #define wl_list_for_each_reverse_safe(pos, tmp, head, member) \ |
501 | for (pos = wl_container_of((head)->prev, pos, member), \ |
502 | tmp = wl_container_of((pos)->member.prev, tmp, member); \ |
503 | &pos->member != (head); \ |
504 | pos = tmp, \ |
505 | tmp = wl_container_of(pos->member.prev, tmp, member)) |
506 | |
507 | /** |
508 | * \class wl_array |
509 | * |
510 | * Dynamic array |
511 | * |
512 | * A wl_array is a dynamic array that can only grow until released. It is |
513 | * intended for relatively small allocations whose size is variable or not known |
514 | * in advance. While construction of a wl_array does not require all elements to |
515 | * be of the same size, wl_array_for_each() does require all elements to have |
516 | * the same type and size. |
517 | * |
518 | */ |
519 | struct wl_array { |
520 | /** Array size */ |
521 | size_t size; |
522 | /** Allocated space */ |
523 | size_t alloc; |
524 | /** Array data */ |
525 | void *data; |
526 | }; |
527 | |
528 | /** |
529 | * Initializes the array. |
530 | * |
531 | * \param array Array to initialize |
532 | * |
533 | * \memberof wl_array |
534 | */ |
535 | void |
536 | wl_array_init(struct wl_array *array); |
537 | |
538 | /** |
539 | * Releases the array data. |
540 | * |
541 | * \note Leaves the array in an invalid state. |
542 | * |
543 | * \param array Array whose data is to be released |
544 | * |
545 | * \memberof wl_array |
546 | */ |
547 | void |
548 | wl_array_release(struct wl_array *array); |
549 | |
550 | /** |
551 | * Increases the size of the array by \p size bytes. |
552 | * |
553 | * \param array Array whose size is to be increased |
554 | * \param size Number of bytes to increase the size of the array by |
555 | * |
556 | * \return A pointer to the beginning of the newly appended space, or NULL when |
557 | * resizing fails. |
558 | * |
559 | * \memberof wl_array |
560 | */ |
561 | void * |
562 | wl_array_add(struct wl_array *array, size_t size); |
563 | |
564 | /** |
565 | * Copies the contents of \p source to \p array. |
566 | * |
567 | * \param array Destination array to copy to |
568 | * \param source Source array to copy from |
569 | * |
570 | * \return 0 on success, or -1 on failure |
571 | * |
572 | * \memberof wl_array |
573 | */ |
574 | int |
575 | wl_array_copy(struct wl_array *array, struct wl_array *source); |
576 | |
577 | /** |
578 | * Iterates over an array. |
579 | * |
580 | * This macro expresses a for-each iterator for wl_array. It assigns each |
581 | * element in the array to \p pos, which can then be referenced in a trailing |
582 | * code block. \p pos must be a pointer to the array element type, and all |
583 | * array elements must be of the same type and size. |
584 | * |
585 | * \param pos Cursor that each array element will be assigned to |
586 | * \param array Array to iterate over |
587 | * |
588 | * \relates wl_array |
589 | * \sa wl_list_for_each() |
590 | */ |
591 | #define wl_array_for_each(pos, array) \ |
592 | for (pos = (array)->data; \ |
593 | (const char *) pos < ((const char *) (array)->data + (array)->size); \ |
594 | (pos)++) |
595 | |
596 | /** |
597 | * Fixed-point number |
598 | * |
599 | * A `wl_fixed_t` is a 24.8 signed fixed-point number with a sign bit, 23 bits |
600 | * of integer precision and 8 bits of decimal precision. Consider `wl_fixed_t` |
601 | * as an opaque struct with methods that facilitate conversion to and from |
602 | * `double` and `int` types. |
603 | */ |
604 | typedef int32_t wl_fixed_t; |
605 | |
606 | /** |
607 | * Converts a fixed-point number to a floating-point number. |
608 | * |
609 | * \param f Fixed-point number to convert |
610 | * |
611 | * \return Floating-point representation of the fixed-point argument |
612 | */ |
613 | static inline double |
614 | wl_fixed_to_double(wl_fixed_t f) |
615 | { |
616 | union { |
617 | double d; |
618 | int64_t i; |
619 | } u; |
620 | |
621 | u.i = ((1023LL + 44LL) << 52) + (1LL << 51) + f; |
622 | |
623 | return u.d - (3LL << 43); |
624 | } |
625 | |
626 | /** |
627 | * Converts a floating-point number to a fixed-point number. |
628 | * |
629 | * \param d Floating-point number to convert |
630 | * |
631 | * \return Fixed-point representation of the floating-point argument |
632 | */ |
633 | static inline wl_fixed_t |
634 | wl_fixed_from_double(double d) |
635 | { |
636 | union { |
637 | double d; |
638 | int64_t i; |
639 | } u; |
640 | |
641 | u.d = d + (3LL << (51 - 8)); |
642 | |
643 | return u.i; |
644 | } |
645 | |
646 | /** |
647 | * Converts a fixed-point number to an integer. |
648 | * |
649 | * \param f Fixed-point number to convert |
650 | * |
651 | * \return Integer component of the fixed-point argument |
652 | */ |
653 | static inline int |
654 | wl_fixed_to_int(wl_fixed_t f) |
655 | { |
656 | return f / 256; |
657 | } |
658 | |
659 | /** |
660 | * Converts an integer to a fixed-point number. |
661 | * |
662 | * \param i Integer to convert |
663 | * |
664 | * \return Fixed-point representation of the integer argument |
665 | */ |
666 | static inline wl_fixed_t |
667 | wl_fixed_from_int(int i) |
668 | { |
669 | return i * 256; |
670 | } |
671 | |
672 | /** |
673 | * Protocol message argument data types |
674 | * |
675 | * This union represents all of the argument types in the Wayland protocol wire |
676 | * format. The protocol implementation uses wl_argument within its marshalling |
677 | * machinery for dispatching messages between a client and a compositor. |
678 | * |
679 | * \sa wl_message |
680 | * \sa wl_interface |
681 | * \sa <a href="https://wayland.freedesktop.org/docs/html/ch04.html#sect-Protocol-wire-Format">Wire Format</a> |
682 | */ |
683 | union wl_argument { |
684 | int32_t i; /**< `int` */ |
685 | uint32_t u; /**< `uint` */ |
686 | wl_fixed_t f; /**< `fixed` */ |
687 | const char *s; /**< `string` */ |
688 | struct wl_object *o; /**< `object` */ |
689 | uint32_t n; /**< `new_id` */ |
690 | struct wl_array *a; /**< `array` */ |
691 | int32_t h; /**< `fd` */ |
692 | }; |
693 | |
694 | /** |
695 | * Dispatcher function type alias |
696 | * |
697 | * A dispatcher is a function that handles the emitting of callbacks in client |
698 | * code. For programs directly using the C library, this is done by using |
699 | * libffi to call function pointers. When binding to languages other than C, |
700 | * dispatchers provide a way to abstract the function calling process to be |
701 | * friendlier to other function calling systems. |
702 | * |
703 | * A dispatcher takes five arguments: The first is the dispatcher-specific |
704 | * implementation associated with the target object. The second is the object |
705 | * upon which the callback is being invoked (either wl_proxy or wl_resource). |
706 | * The third and fourth arguments are the opcode and the wl_message |
707 | * corresponding to the callback. The final argument is an array of arguments |
708 | * received from the other process via the wire protocol. |
709 | * |
710 | * \param "const void *" Dispatcher-specific implementation data |
711 | * \param "void *" Callback invocation target (wl_proxy or `wl_resource`) |
712 | * \param uint32_t Callback opcode |
713 | * \param "const struct wl_message *" Callback message signature |
714 | * \param "union wl_argument *" Array of received arguments |
715 | * |
716 | * \return 0 on success, or -1 on failure |
717 | */ |
718 | typedef int (*wl_dispatcher_func_t)(const void *, void *, uint32_t, |
719 | const struct wl_message *, |
720 | union wl_argument *); |
721 | |
722 | /** |
723 | * Log function type alias |
724 | * |
725 | * The C implementation of the Wayland protocol abstracts the details of |
726 | * logging. Users may customize the logging behavior, with a function conforming |
727 | * to the `wl_log_func_t` type, via `wl_log_set_handler_client` and |
728 | * `wl_log_set_handler_server`. |
729 | * |
730 | * A `wl_log_func_t` must conform to the expectations of `vprintf`, and |
731 | * expects two arguments: a string to write and a corresponding variable |
732 | * argument list. While the string to write may contain format specifiers and |
733 | * use values in the variable argument list, the behavior of any `wl_log_func_t` |
734 | * depends on the implementation. |
735 | * |
736 | * \note Take care to not confuse this with `wl_protocol_logger_func_t`, which |
737 | * is a specific server-side logger for requests and events. |
738 | * |
739 | * \param "const char *" String to write to the log, containing optional format |
740 | * specifiers |
741 | * \param "va_list" Variable argument list |
742 | * |
743 | * \sa wl_log_set_handler_client |
744 | * \sa wl_log_set_handler_server |
745 | */ |
746 | typedef void (*wl_log_func_t)(const char *, va_list) WL_PRINTF(1, 0); |
747 | |
748 | /** |
749 | * Return value of an iterator function |
750 | * |
751 | * \sa wl_client_for_each_resource_iterator_func_t |
752 | * \sa wl_client_for_each_resource |
753 | */ |
754 | enum wl_iterator_result { |
755 | /** Stop the iteration */ |
756 | WL_ITERATOR_STOP, |
757 | /** Continue the iteration */ |
758 | WL_ITERATOR_CONTINUE |
759 | }; |
760 | |
761 | #ifdef __cplusplus |
762 | } |
763 | #endif |
764 | |
765 | #endif |
766 | |