1 /*
2 * Copyright © 2008 Kristian Høgsberg
3 * Copyright © 2020 Andri Yngvason
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 */
24
25 #define _POSIX_C_SOURCE 200112L
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <limits.h>
29 #include <png.h>
30 #include <stdbool.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <sys/mman.h>
35 #include <sys/param.h>
36 #include <sys/stat.h>
37 #include <sys/wait.h>
38 #include <unistd.h>
39 #include <assert.h>
40 #include <gbm.h>
41 #include <xf86drm.h>
42 #include <drm_fourcc.h>
43 #include <wayland-client-protocol.h>
44 #include "wlr-screencopy-unstable-v1-client-protocol.h"
45 #include "linux-dmabuf-unstable-v1-client-protocol.h"
46
47 struct format {
48 uint32_t format;
49 bool is_bgr;
50 };
51
52 static int drm_fd = -1;
53 static struct gbm_device *gbm_device = NULL;
54
55 static struct zwp_linux_dmabuf_v1 *dmabuf = NULL;
56 static struct zwlr_screencopy_manager_v1 *screencopy_manager = NULL;
57 static struct wl_output *output = NULL;
58
59 static struct {
60 struct gbm_bo *bo;
61 struct wl_buffer *wl_buffer;
62 int width, height;
63 uint32_t format;
64 bool y_invert;
65 } buffer;
66
67 bool buffer_copy_done = false;
68 static bool have_linux_dmabuf = false;
69
70 // wl_shm_format describes little-endian formats, libpng uses big-endian
71 // formats (so Wayland's ABGR is libpng's RGBA).
72 static const struct format formats[] = {
73 {DRM_FORMAT_XRGB8888, true},
74 {DRM_FORMAT_ARGB8888, true},
75 {DRM_FORMAT_XBGR8888, false},
76 {DRM_FORMAT_ABGR8888, false},
77 };
78
find_render_node(char * node,size_t maxlen)79 static bool find_render_node(char *node, size_t maxlen) {
80 bool r = false;
81 drmDevice *devices[64];
82
83 int n = drmGetDevices2(0, devices, sizeof(devices) / sizeof(devices[0]));
84 for (int i = 0; i < n; ++i) {
85 drmDevice *dev = devices[i];
86 if (!(dev->available_nodes & (1 << DRM_NODE_RENDER))) {
87 continue;
88 }
89
90 strncpy(node, dev->nodes[DRM_NODE_RENDER], maxlen - 1);
91 node[maxlen - 1] = '\0';
92 r = true;
93 break;
94 }
95
96 drmFreeDevices(devices, n);
97 return r;
98 }
99
dmabuf_created(void * data,struct zwp_linux_buffer_params_v1 * params,struct wl_buffer * wl_buffer)100 static void dmabuf_created(void *data,
101 struct zwp_linux_buffer_params_v1 *params,
102 struct wl_buffer *wl_buffer) {
103 buffer.wl_buffer = wl_buffer;
104
105 zwlr_screencopy_frame_v1_copy(data, buffer.wl_buffer);
106 }
107
dmabuf_failed(void * data,struct zwp_linux_buffer_params_v1 * params)108 static void dmabuf_failed(void *data,
109 struct zwp_linux_buffer_params_v1 *params) {
110 fprintf(stderr, "Failed to create dmabuf\n");
111 exit(EXIT_FAILURE);
112 }
113
114 static const struct zwp_linux_buffer_params_v1_listener params_listener = {
115 .created = dmabuf_created,
116 .failed = dmabuf_failed,
117 };
118
frame_handle_buffer(void * data,struct zwlr_screencopy_frame_v1 * frame,uint32_t wl_format,uint32_t width,uint32_t height,uint32_t stride)119 static void frame_handle_buffer(void *data,
120 struct zwlr_screencopy_frame_v1 *frame, uint32_t wl_format,
121 uint32_t width, uint32_t height, uint32_t stride) {
122 // Not implemented
123 }
124
frame_handle_linux_dmabuf(void * data,struct zwlr_screencopy_frame_v1 * frame,uint32_t fourcc,uint32_t width,uint32_t height)125 static void frame_handle_linux_dmabuf(void *data,
126 struct zwlr_screencopy_frame_v1 *frame, uint32_t fourcc,
127 uint32_t width, uint32_t height) {
128 buffer.width = width;
129 buffer.height = height;
130 buffer.format = fourcc;
131 have_linux_dmabuf = true;
132 }
133
frame_handle_buffer_done(void * data,struct zwlr_screencopy_frame_v1 * frame)134 static void frame_handle_buffer_done(void *data,
135 struct zwlr_screencopy_frame_v1 *frame) {
136 assert(!buffer.bo);
137
138 if (!have_linux_dmabuf) {
139 fprintf(stderr, "linux-dmabuf is not supported\n");
140 exit(EXIT_FAILURE);
141 }
142
143 buffer.bo = gbm_bo_create(gbm_device, buffer.width, buffer.height,
144 buffer.format,
145 GBM_BO_USE_LINEAR | GBM_BO_USE_RENDERING);
146 if (buffer.bo == NULL) {
147 fprintf(stderr, "failed to create GBM buffer object\n");
148 exit(EXIT_FAILURE);
149 }
150
151 struct zwp_linux_buffer_params_v1 *params;
152 params = zwp_linux_dmabuf_v1_create_params(dmabuf);
153 assert(params);
154
155 int fd = gbm_bo_get_fd(buffer.bo);
156 uint32_t off = gbm_bo_get_offset(buffer.bo, 0);
157 uint32_t bo_stride = gbm_bo_get_stride(buffer.bo);
158 uint64_t mod = gbm_bo_get_modifier(buffer.bo);
159 zwp_linux_buffer_params_v1_add(params, fd, 0, off, bo_stride, mod >> 32,
160 mod & 0xffffffff);
161
162 zwp_linux_buffer_params_v1_add_listener(params, ¶ms_listener, frame);
163
164 zwp_linux_buffer_params_v1_create(params, buffer.width, buffer.height,
165 buffer.format, /* flags */ 0);
166 }
167
frame_handle_flags(void * data,struct zwlr_screencopy_frame_v1 * frame,uint32_t flags)168 static void frame_handle_flags(void *data,
169 struct zwlr_screencopy_frame_v1 *frame, uint32_t flags) {
170 buffer.y_invert = flags & ZWLR_SCREENCOPY_FRAME_V1_FLAGS_Y_INVERT;
171 }
172
frame_handle_ready(void * data,struct zwlr_screencopy_frame_v1 * frame,uint32_t tv_sec_hi,uint32_t tv_sec_lo,uint32_t tv_nsec)173 static void frame_handle_ready(void *data,
174 struct zwlr_screencopy_frame_v1 *frame, uint32_t tv_sec_hi,
175 uint32_t tv_sec_lo, uint32_t tv_nsec) {
176 buffer_copy_done = true;
177 }
178
frame_handle_failed(void * data,struct zwlr_screencopy_frame_v1 * frame)179 static void frame_handle_failed(void *data,
180 struct zwlr_screencopy_frame_v1 *frame) {
181 fprintf(stderr, "failed to copy frame\n");
182 exit(EXIT_FAILURE);
183 }
184
185 static const struct zwlr_screencopy_frame_v1_listener frame_listener = {
186 .buffer = frame_handle_buffer,
187 .linux_dmabuf = frame_handle_linux_dmabuf,
188 .buffer_done = frame_handle_buffer_done,
189 .flags = frame_handle_flags,
190 .ready = frame_handle_ready,
191 .failed = frame_handle_failed,
192 };
193
dmabuf_format(void * data,struct zwp_linux_dmabuf_v1 * zwp_linux_dmabuf,uint32_t format)194 static void dmabuf_format(void *data,
195 struct zwp_linux_dmabuf_v1 *zwp_linux_dmabuf, uint32_t format) {
196 // deprecated
197 }
198
dmabuf_modifier(void * data,struct zwp_linux_dmabuf_v1 * zwp_linux_dmabuf,uint32_t format,uint32_t modifier_hi,uint32_t modifier_lo)199 static void dmabuf_modifier(void *data,
200 struct zwp_linux_dmabuf_v1 *zwp_linux_dmabuf, uint32_t format,
201 uint32_t modifier_hi, uint32_t modifier_lo) {
202 // TODO?
203 }
204
205 static const struct zwp_linux_dmabuf_v1_listener dmabuf_listener = {
206 .format = dmabuf_format,
207 .modifier = dmabuf_modifier,
208 };
209
handle_global(void * data,struct wl_registry * registry,uint32_t name,const char * interface,uint32_t version)210 static void handle_global(void *data, struct wl_registry *registry,
211 uint32_t name, const char *interface, uint32_t version) {
212 if (strcmp(interface, wl_output_interface.name) == 0 && output == NULL) {
213 output = wl_registry_bind(registry, name, &wl_output_interface, 1);
214 } else if (strcmp(interface, zwp_linux_dmabuf_v1_interface.name) == 0) {
215 dmabuf = wl_registry_bind(registry, name,
216 &zwp_linux_dmabuf_v1_interface, 3);
217 zwp_linux_dmabuf_v1_add_listener(dmabuf, &dmabuf_listener, data);
218 } else if (strcmp(interface,
219 zwlr_screencopy_manager_v1_interface.name) == 0) {
220 screencopy_manager = wl_registry_bind(registry, name,
221 &zwlr_screencopy_manager_v1_interface, 3);
222 }
223 }
224
handle_global_remove(void * data,struct wl_registry * registry,uint32_t name)225 static void handle_global_remove(void *data, struct wl_registry *registry,
226 uint32_t name) {
227 // Who cares?
228 }
229
230 static const struct wl_registry_listener registry_listener = {
231 .global = handle_global,
232 .global_remove = handle_global_remove,
233 };
234
write_image(char * filename,uint32_t format,int width,int height,int stride,bool y_invert,png_bytep data)235 static void write_image(char *filename, uint32_t format, int width,
236 int height, int stride, bool y_invert, png_bytep data) {
237 const struct format *fmt = NULL;
238 for (size_t i = 0; i < sizeof(formats) / sizeof(formats[0]); ++i) {
239 if (formats[i].format == format) {
240 fmt = &formats[i];
241 break;
242 }
243 }
244
245 if (fmt == NULL) {
246 fprintf(stderr, "unsupported format %"PRIu32"\n", format);
247 exit(EXIT_FAILURE);
248 }
249
250 FILE *f = fopen(filename, "wb");
251 if (f == NULL) {
252 fprintf(stderr, "failed to open output file\n");
253 exit(EXIT_FAILURE);
254 }
255
256 png_structp png =
257 png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
258 png_infop info = png_create_info_struct(png);
259
260 png_init_io(png, f);
261
262 png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_RGBA,
263 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
264 PNG_FILTER_TYPE_DEFAULT);
265
266 if (fmt->is_bgr) {
267 png_set_bgr(png);
268 }
269
270 png_write_info(png, info);
271
272 for (size_t i = 0; i < (size_t)height; ++i) {
273 png_bytep row;
274 if (y_invert) {
275 row = data + (height - i - 1) * stride;
276 } else {
277 row = data + i * stride;
278 }
279 png_write_row(png, row);
280 }
281
282 png_write_end(png, NULL);
283
284 png_destroy_write_struct(&png, &info);
285
286 fclose(f);
287 }
288
main(int argc,char * argv[])289 int main(int argc, char *argv[]) {
290 char render_node[256];
291 if (!find_render_node(render_node, sizeof(render_node))) {
292 fprintf(stderr, "Failed to find a DRM render node\n");
293 return EXIT_FAILURE;
294 }
295
296 printf("Using render node: %s\n", render_node);
297
298 drm_fd = open(render_node, O_RDWR);
299 if (drm_fd < 0) {
300 perror("Failed to open drm render node");
301 return EXIT_FAILURE;
302 }
303
304 gbm_device = gbm_create_device(drm_fd);
305 if (!gbm_device) {
306 fprintf(stderr, "Failed to create gbm device\n");
307 return EXIT_FAILURE;
308 }
309
310 struct wl_display *display = wl_display_connect(NULL);
311 if (display == NULL) {
312 perror("failed to create display");
313 return EXIT_FAILURE;
314 }
315
316 struct wl_registry *registry = wl_display_get_registry(display);
317 wl_registry_add_listener(registry, ®istry_listener, NULL);
318 wl_display_roundtrip(display);
319
320 if (dmabuf == NULL) {
321 fprintf(stderr, "compositor is missing linux-dmabuf-unstable-v1\n");
322 return EXIT_FAILURE;
323 }
324 if (screencopy_manager == NULL) {
325 fprintf(stderr, "compositor doesn't support wlr-screencopy-unstable-v1\n");
326 return EXIT_FAILURE;
327 }
328 if (output == NULL) {
329 fprintf(stderr, "no output available\n");
330 return EXIT_FAILURE;
331 }
332
333 struct zwlr_screencopy_frame_v1 *frame =
334 zwlr_screencopy_manager_v1_capture_output(screencopy_manager, 0, output);
335 zwlr_screencopy_frame_v1_add_listener(frame, &frame_listener, NULL);
336
337 while (!buffer_copy_done && wl_display_dispatch(display) != -1) {
338 // This space is intentionally left blank
339 }
340
341 uint32_t stride = 0;
342 void *map_data = NULL;
343 void *data = gbm_bo_map(buffer.bo, 0, 0, buffer.width, buffer.height,
344 GBM_BO_TRANSFER_READ, &stride, &map_data);
345 if (!data) {
346 perror("Failed to map gbm bo");
347 return EXIT_FAILURE;
348 }
349
350 write_image("wayland-screenshot.png", buffer.format, buffer.width,
351 buffer.height, stride, buffer.y_invert, data);
352
353 gbm_bo_unmap(buffer.bo, map_data);
354 gbm_bo_destroy(buffer.bo);
355 wl_buffer_destroy(buffer.wl_buffer);
356
357 gbm_device_destroy(gbm_device);
358 close(drm_fd);
359
360 return EXIT_SUCCESS;
361 }
362