xref: /openbmc/qemu/ui/egl-helpers.c (revision 53c7c924)
1 /*
2  * Copyright (C) 2015-2016 Gerd Hoffmann <kraxel@redhat.com>
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
16  */
17 #include "qemu/osdep.h"
18 
19 #include "qemu/drm.h"
20 #include "qemu/error-report.h"
21 #include "ui/console.h"
22 #include "ui/egl-helpers.h"
23 #include "sysemu/sysemu.h"
24 #include "qapi/error.h"
25 #include "trace.h"
26 
27 EGLDisplay *qemu_egl_display;
28 EGLConfig qemu_egl_config;
29 DisplayGLMode qemu_egl_mode;
30 bool qemu_egl_angle_d3d;
31 
32 /* ------------------------------------------------------------------ */
33 
34 const char *qemu_egl_get_error_string(void)
35 {
36     EGLint error = eglGetError();
37 
38     switch (error) {
39     case EGL_SUCCESS:
40         return "EGL_SUCCESS";
41     case EGL_NOT_INITIALIZED:
42         return "EGL_NOT_INITIALIZED";
43     case EGL_BAD_ACCESS:
44         return "EGL_BAD_ACCESS";
45     case EGL_BAD_ALLOC:
46         return "EGL_BAD_ALLOC";
47     case EGL_BAD_ATTRIBUTE:
48         return "EGL_BAD_ATTRIBUTE";
49     case EGL_BAD_CONTEXT:
50         return "EGL_BAD_CONTEXT";
51     case EGL_BAD_CONFIG:
52         return "EGL_BAD_CONFIG";
53     case EGL_BAD_CURRENT_SURFACE:
54         return "EGL_BAD_CURRENT_SURFACE";
55     case EGL_BAD_DISPLAY:
56         return "EGL_BAD_DISPLAY";
57     case EGL_BAD_SURFACE:
58         return "EGL_BAD_SURFACE";
59     case EGL_BAD_MATCH:
60         return "EGL_BAD_MATCH";
61     case EGL_BAD_PARAMETER:
62         return "EGL_BAD_PARAMETER";
63     case EGL_BAD_NATIVE_PIXMAP:
64         return "EGL_BAD_NATIVE_PIXMAP";
65     case EGL_BAD_NATIVE_WINDOW:
66         return "EGL_BAD_NATIVE_WINDOW";
67     case EGL_CONTEXT_LOST:
68         return "EGL_CONTEXT_LOST";
69     default:
70         return "Unknown EGL error";
71     }
72 }
73 
74 static void egl_fb_delete_texture(egl_fb *fb)
75 {
76     if (!fb->delete_texture) {
77         return;
78     }
79 
80     glDeleteTextures(1, &fb->texture);
81     fb->delete_texture = false;
82 }
83 
84 void egl_fb_destroy(egl_fb *fb)
85 {
86     if (!fb->framebuffer) {
87         return;
88     }
89 
90     egl_fb_delete_texture(fb);
91     glDeleteFramebuffers(1, &fb->framebuffer);
92 
93     fb->width = 0;
94     fb->height = 0;
95     fb->texture = 0;
96     fb->framebuffer = 0;
97 }
98 
99 void egl_fb_setup_default(egl_fb *fb, int width, int height)
100 {
101     fb->width = width;
102     fb->height = height;
103     fb->framebuffer = 0; /* default framebuffer */
104 }
105 
106 void egl_fb_setup_for_tex(egl_fb *fb, int width, int height,
107                           GLuint texture, bool delete)
108 {
109     egl_fb_delete_texture(fb);
110 
111     fb->width = width;
112     fb->height = height;
113     fb->texture = texture;
114     fb->delete_texture = delete;
115     if (!fb->framebuffer) {
116         glGenFramebuffers(1, &fb->framebuffer);
117     }
118 
119     glBindFramebuffer(GL_FRAMEBUFFER_EXT, fb->framebuffer);
120     glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
121                               GL_TEXTURE_2D, fb->texture, 0);
122 }
123 
124 void egl_fb_setup_new_tex(egl_fb *fb, int width, int height)
125 {
126     GLuint texture;
127 
128     glGenTextures(1, &texture);
129     glBindTexture(GL_TEXTURE_2D, texture);
130     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height,
131                  0, GL_BGRA, GL_UNSIGNED_BYTE, 0);
132 
133     egl_fb_setup_for_tex(fb, width, height, texture, true);
134 }
135 
136 void egl_fb_blit(egl_fb *dst, egl_fb *src, bool flip)
137 {
138     GLuint x1 = 0;
139     GLuint y1 = 0;
140     GLuint x2, y2;
141     GLuint w = src->width;
142     GLuint h = src->height;
143 
144     glBindFramebuffer(GL_READ_FRAMEBUFFER, src->framebuffer);
145     glBindFramebuffer(GL_DRAW_FRAMEBUFFER, dst->framebuffer);
146     glViewport(0, 0, dst->width, dst->height);
147 
148     if (src->dmabuf) {
149         x1 = src->dmabuf->x;
150         y1 = src->dmabuf->y;
151         w = src->dmabuf->width;
152         h = src->dmabuf->height;
153     }
154 
155     w = (x1 + w) > src->width ? src->width - x1 : w;
156     h = (y1 + h) > src->height ? src->height - y1 : h;
157 
158     y2 = flip ? y1 : h + y1;
159     y1 = flip ? h + y1 : y1;
160     x2 = x1 + w;
161 
162     glBlitFramebuffer(x1, y1, x2, y2,
163                       0, 0, dst->width, dst->height,
164                       GL_COLOR_BUFFER_BIT, GL_LINEAR);
165 }
166 
167 void egl_fb_read(DisplaySurface *dst, egl_fb *src)
168 {
169     glBindFramebuffer(GL_READ_FRAMEBUFFER, src->framebuffer);
170     glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
171     glReadPixels(0, 0, surface_width(dst), surface_height(dst),
172                  GL_BGRA, GL_UNSIGNED_BYTE, surface_data(dst));
173 }
174 
175 void egl_fb_read_rect(DisplaySurface *dst, egl_fb *src, int x, int y, int w, int h)
176 {
177     assert(surface_width(dst) == src->width);
178     assert(surface_height(dst) == src->height);
179     assert(surface_format(dst) == PIXMAN_x8r8g8b8);
180 
181     glBindFramebuffer(GL_READ_FRAMEBUFFER, src->framebuffer);
182     glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
183     glPixelStorei(GL_PACK_ROW_LENGTH, surface_stride(dst) / 4);
184     glReadPixels(x, y, w, h,
185                  GL_BGRA, GL_UNSIGNED_BYTE, surface_data(dst) + x * 4);
186     glPixelStorei(GL_PACK_ROW_LENGTH, 0);
187 }
188 
189 void egl_texture_blit(QemuGLShader *gls, egl_fb *dst, egl_fb *src, bool flip)
190 {
191     glBindFramebuffer(GL_FRAMEBUFFER_EXT, dst->framebuffer);
192     glViewport(0, 0, dst->width, dst->height);
193     glEnable(GL_TEXTURE_2D);
194     glBindTexture(GL_TEXTURE_2D, src->texture);
195     qemu_gl_run_texture_blit(gls, flip);
196 }
197 
198 void egl_texture_blend(QemuGLShader *gls, egl_fb *dst, egl_fb *src, bool flip,
199                        int x, int y, double scale_x, double scale_y)
200 {
201     glBindFramebuffer(GL_FRAMEBUFFER_EXT, dst->framebuffer);
202     int w = scale_x * src->width;
203     int h = scale_y * src->height;
204     if (flip) {
205         glViewport(x, y, w, h);
206     } else {
207         glViewport(x, dst->height - h - y, w, h);
208     }
209     glEnable(GL_TEXTURE_2D);
210     glBindTexture(GL_TEXTURE_2D, src->texture);
211     glEnable(GL_BLEND);
212     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
213     qemu_gl_run_texture_blit(gls, flip);
214     glDisable(GL_BLEND);
215 }
216 
217 /* ---------------------------------------------------------------------- */
218 
219 EGLContext qemu_egl_rn_ctx;
220 
221 #ifdef CONFIG_GBM
222 
223 int qemu_egl_rn_fd;
224 struct gbm_device *qemu_egl_rn_gbm_dev;
225 
226 int egl_rendernode_init(const char *rendernode, DisplayGLMode mode)
227 {
228     qemu_egl_rn_fd = -1;
229     int rc;
230 
231     qemu_egl_rn_fd = qemu_drm_rendernode_open(rendernode);
232     if (qemu_egl_rn_fd == -1) {
233         error_report("egl: no drm render node available");
234         goto err;
235     }
236 
237     qemu_egl_rn_gbm_dev = gbm_create_device(qemu_egl_rn_fd);
238     if (!qemu_egl_rn_gbm_dev) {
239         error_report("egl: gbm_create_device failed");
240         goto err;
241     }
242 
243     rc = qemu_egl_init_dpy_mesa((EGLNativeDisplayType)qemu_egl_rn_gbm_dev,
244                                 mode);
245     if (rc != 0) {
246         /* qemu_egl_init_dpy_mesa reports error */
247         goto err;
248     }
249 
250     if (!epoxy_has_egl_extension(qemu_egl_display,
251                                  "EGL_KHR_surfaceless_context")) {
252         error_report("egl: EGL_KHR_surfaceless_context not supported");
253         goto err;
254     }
255     if (!epoxy_has_egl_extension(qemu_egl_display,
256                                  "EGL_MESA_image_dma_buf_export")) {
257         error_report("egl: EGL_MESA_image_dma_buf_export not supported");
258         goto err;
259     }
260 
261     qemu_egl_rn_ctx = qemu_egl_init_ctx();
262     if (!qemu_egl_rn_ctx) {
263         error_report("egl: egl_init_ctx failed");
264         goto err;
265     }
266 
267     return 0;
268 
269 err:
270     if (qemu_egl_rn_gbm_dev) {
271         gbm_device_destroy(qemu_egl_rn_gbm_dev);
272     }
273     if (qemu_egl_rn_fd != -1) {
274         close(qemu_egl_rn_fd);
275     }
276 
277     return -1;
278 }
279 
280 int egl_get_fd_for_texture(uint32_t tex_id, EGLint *stride, EGLint *fourcc,
281                            EGLuint64KHR *modifier)
282 {
283     EGLImageKHR image;
284     EGLint num_planes, fd;
285 
286     image = eglCreateImageKHR(qemu_egl_display, eglGetCurrentContext(),
287                               EGL_GL_TEXTURE_2D_KHR,
288                               (EGLClientBuffer)(unsigned long)tex_id,
289                               NULL);
290     if (!image) {
291         return -1;
292     }
293 
294     eglExportDMABUFImageQueryMESA(qemu_egl_display, image, fourcc,
295                                   &num_planes, modifier);
296     if (num_planes != 1) {
297         eglDestroyImageKHR(qemu_egl_display, image);
298         return -1;
299     }
300     eglExportDMABUFImageMESA(qemu_egl_display, image, &fd, stride, NULL);
301     eglDestroyImageKHR(qemu_egl_display, image);
302 
303     return fd;
304 }
305 
306 void egl_dmabuf_import_texture(QemuDmaBuf *dmabuf)
307 {
308     EGLImageKHR image = EGL_NO_IMAGE_KHR;
309     EGLint attrs[64];
310     int i = 0;
311 
312     if (dmabuf->texture != 0) {
313         return;
314     }
315 
316     attrs[i++] = EGL_WIDTH;
317     attrs[i++] = dmabuf->backing_width;
318     attrs[i++] = EGL_HEIGHT;
319     attrs[i++] = dmabuf->backing_height;
320     attrs[i++] = EGL_LINUX_DRM_FOURCC_EXT;
321     attrs[i++] = dmabuf->fourcc;
322 
323     attrs[i++] = EGL_DMA_BUF_PLANE0_FD_EXT;
324     attrs[i++] = dmabuf->fd;
325     attrs[i++] = EGL_DMA_BUF_PLANE0_PITCH_EXT;
326     attrs[i++] = dmabuf->stride;
327     attrs[i++] = EGL_DMA_BUF_PLANE0_OFFSET_EXT;
328     attrs[i++] = 0;
329 #ifdef EGL_DMA_BUF_PLANE0_MODIFIER_LO_EXT
330     if (dmabuf->modifier) {
331         attrs[i++] = EGL_DMA_BUF_PLANE0_MODIFIER_LO_EXT;
332         attrs[i++] = (dmabuf->modifier >>  0) & 0xffffffff;
333         attrs[i++] = EGL_DMA_BUF_PLANE0_MODIFIER_HI_EXT;
334         attrs[i++] = (dmabuf->modifier >> 32) & 0xffffffff;
335     }
336 #endif
337     attrs[i++] = EGL_NONE;
338 
339     image = eglCreateImageKHR(qemu_egl_display,
340                               EGL_NO_CONTEXT,
341                               EGL_LINUX_DMA_BUF_EXT,
342                               NULL, attrs);
343     if (image == EGL_NO_IMAGE_KHR) {
344         error_report("eglCreateImageKHR failed");
345         return;
346     }
347 
348     glGenTextures(1, &dmabuf->texture);
349     glBindTexture(GL_TEXTURE_2D, dmabuf->texture);
350     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
351     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
352 
353     glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, (GLeglImageOES)image);
354     eglDestroyImageKHR(qemu_egl_display, image);
355 }
356 
357 void egl_dmabuf_release_texture(QemuDmaBuf *dmabuf)
358 {
359     if (dmabuf->texture == 0) {
360         return;
361     }
362 
363     glDeleteTextures(1, &dmabuf->texture);
364     dmabuf->texture = 0;
365 }
366 
367 void egl_dmabuf_create_sync(QemuDmaBuf *dmabuf)
368 {
369     EGLSyncKHR sync;
370 
371     if (epoxy_has_egl_extension(qemu_egl_display,
372                                 "EGL_KHR_fence_sync") &&
373         epoxy_has_egl_extension(qemu_egl_display,
374                                 "EGL_ANDROID_native_fence_sync")) {
375         sync = eglCreateSyncKHR(qemu_egl_display,
376                                 EGL_SYNC_NATIVE_FENCE_ANDROID, NULL);
377         if (sync != EGL_NO_SYNC_KHR) {
378             dmabuf->sync = sync;
379         }
380     }
381 }
382 
383 void egl_dmabuf_create_fence(QemuDmaBuf *dmabuf)
384 {
385     if (dmabuf->sync) {
386         dmabuf->fence_fd = eglDupNativeFenceFDANDROID(qemu_egl_display,
387                                                       dmabuf->sync);
388         eglDestroySyncKHR(qemu_egl_display, dmabuf->sync);
389         dmabuf->sync = NULL;
390     }
391 }
392 
393 #endif /* CONFIG_GBM */
394 
395 /* ---------------------------------------------------------------------- */
396 
397 EGLSurface qemu_egl_init_surface_x11(EGLContext ectx, EGLNativeWindowType win)
398 {
399     EGLSurface esurface;
400     EGLBoolean b;
401 
402     esurface = eglCreateWindowSurface(qemu_egl_display,
403                                       qemu_egl_config,
404                                       win, NULL);
405     if (esurface == EGL_NO_SURFACE) {
406         error_report("egl: eglCreateWindowSurface failed");
407         return NULL;
408     }
409 
410     b = eglMakeCurrent(qemu_egl_display, esurface, esurface, ectx);
411     if (b == EGL_FALSE) {
412         error_report("egl: eglMakeCurrent failed");
413         return NULL;
414     }
415 
416     return esurface;
417 }
418 
419 /* ---------------------------------------------------------------------- */
420 
421 #if defined(CONFIG_X11) || defined(CONFIG_GBM) || defined(WIN32)
422 
423 /*
424  * Taken from glamor_egl.h from the Xorg xserver, which is MIT licensed
425  *
426  * Create an EGLDisplay from a native display type. This is a little quirky
427  * for a few reasons.
428  *
429  * 1: GetPlatformDisplayEXT and GetPlatformDisplay are the API you want to
430  * use, but have different function signatures in the third argument; this
431  * happens not to matter for us, at the moment, but it means epoxy won't alias
432  * them together.
433  *
434  * 2: epoxy 1.3 and earlier don't understand EGL client extensions, which
435  * means you can't call "eglGetPlatformDisplayEXT" directly, as the resolver
436  * will crash.
437  *
438  * 3: You can't tell whether you have EGL 1.5 at this point, because
439  * eglQueryString(EGL_VERSION) is a property of the display, which we don't
440  * have yet. So you have to query for extensions no matter what. Fortunately
441  * epoxy_has_egl_extension _does_ let you query for client extensions, so
442  * we don't have to write our own extension string parsing.
443  *
444  * 4. There is no EGL_KHR_platform_base to complement the EXT one, thus one
445  * needs to know EGL 1.5 is supported in order to use the eglGetPlatformDisplay
446  * function pointer.
447  * We can workaround this (circular dependency) by probing for the EGL 1.5
448  * platform extensions (EGL_KHR_platform_gbm and friends) yet it doesn't seem
449  * like mesa will be able to advertise these (even though it can do EGL 1.5).
450  */
451 static EGLDisplay qemu_egl_get_display(EGLNativeDisplayType native,
452                                        EGLenum platform)
453 {
454     EGLDisplay dpy = EGL_NO_DISPLAY;
455 
456     /* In practise any EGL 1.5 implementation would support the EXT extension */
457     if (epoxy_has_egl_extension(NULL, "EGL_EXT_platform_base")) {
458         if (platform != 0) {
459             dpy = eglGetPlatformDisplayEXT(platform, native, NULL);
460         }
461     }
462 
463     if (dpy == EGL_NO_DISPLAY) {
464         /* fallback */
465         dpy = eglGetDisplay(native);
466     }
467     return dpy;
468 }
469 
470 static int qemu_egl_init_dpy(EGLNativeDisplayType dpy,
471                              EGLenum platform,
472                              DisplayGLMode mode)
473 {
474     static const EGLint conf_att_core[] = {
475         EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
476         EGL_RENDERABLE_TYPE, EGL_OPENGL_BIT,
477         EGL_RED_SIZE,   5,
478         EGL_GREEN_SIZE, 5,
479         EGL_BLUE_SIZE,  5,
480         EGL_ALPHA_SIZE, 0,
481         EGL_NONE,
482     };
483     static const EGLint conf_att_gles[] = {
484         EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
485         EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
486         EGL_RED_SIZE,   5,
487         EGL_GREEN_SIZE, 5,
488         EGL_BLUE_SIZE,  5,
489         EGL_ALPHA_SIZE, 0,
490         EGL_NONE,
491     };
492     EGLint major, minor;
493     EGLBoolean b;
494     EGLint n;
495     bool gles = (mode == DISPLAYGL_MODE_ES);
496 
497     qemu_egl_display = qemu_egl_get_display(dpy, platform);
498     if (qemu_egl_display == EGL_NO_DISPLAY) {
499         error_report("egl: eglGetDisplay failed: %s", qemu_egl_get_error_string());
500         return -1;
501     }
502 
503     b = eglInitialize(qemu_egl_display, &major, &minor);
504     if (b == EGL_FALSE) {
505         error_report("egl: eglInitialize failed: %s", qemu_egl_get_error_string());
506         return -1;
507     }
508 
509     b = eglBindAPI(gles ?  EGL_OPENGL_ES_API : EGL_OPENGL_API);
510     if (b == EGL_FALSE) {
511         error_report("egl: eglBindAPI failed (%s mode): %s",
512                      gles ? "gles" : "core", qemu_egl_get_error_string());
513         return -1;
514     }
515 
516     b = eglChooseConfig(qemu_egl_display,
517                         gles ? conf_att_gles : conf_att_core,
518                         &qemu_egl_config, 1, &n);
519     if (b == EGL_FALSE || n != 1) {
520         error_report("egl: eglChooseConfig failed (%s mode): %s",
521                      gles ? "gles" : "core", qemu_egl_get_error_string());
522         return -1;
523     }
524 
525     qemu_egl_mode = gles ? DISPLAYGL_MODE_ES : DISPLAYGL_MODE_CORE;
526     return 0;
527 }
528 
529 #endif
530 
531 #if defined(CONFIG_X11) || defined(CONFIG_GBM)
532 int qemu_egl_init_dpy_x11(EGLNativeDisplayType dpy, DisplayGLMode mode)
533 {
534 #ifdef EGL_KHR_platform_x11
535     return qemu_egl_init_dpy(dpy, EGL_PLATFORM_X11_KHR, mode);
536 #else
537     return qemu_egl_init_dpy(dpy, 0, mode);
538 #endif
539 }
540 
541 int qemu_egl_init_dpy_mesa(EGLNativeDisplayType dpy, DisplayGLMode mode)
542 {
543 #ifdef EGL_MESA_platform_gbm
544     return qemu_egl_init_dpy(dpy, EGL_PLATFORM_GBM_MESA, mode);
545 #else
546     return qemu_egl_init_dpy(dpy, 0, mode);
547 #endif
548 }
549 #endif
550 
551 
552 #ifdef WIN32
553 int qemu_egl_init_dpy_win32(EGLNativeDisplayType dpy, DisplayGLMode mode)
554 {
555     /* prefer GL ES, as that's what ANGLE supports */
556     if (mode == DISPLAYGL_MODE_ON) {
557         mode = DISPLAYGL_MODE_ES;
558     }
559 
560     if (qemu_egl_init_dpy(dpy, 0, mode) < 0) {
561         return -1;
562     }
563 
564 #ifdef EGL_D3D11_DEVICE_ANGLE
565     if (epoxy_has_egl_extension(qemu_egl_display, "EGL_EXT_device_query")) {
566         EGLDeviceEXT device;
567         void *d3d11_device;
568 
569         if (!eglQueryDisplayAttribEXT(qemu_egl_display,
570                                       EGL_DEVICE_EXT,
571                                       (EGLAttrib *)&device)) {
572             return 0;
573         }
574 
575         if (!eglQueryDeviceAttribEXT(device,
576                                      EGL_D3D11_DEVICE_ANGLE,
577                                      (EGLAttrib *)&d3d11_device)) {
578             return 0;
579         }
580 
581         trace_egl_init_d3d11_device(device);
582         qemu_egl_angle_d3d = device != NULL;
583     }
584 #endif
585 
586     return 0;
587 }
588 #endif
589 
590 bool qemu_egl_has_dmabuf(void)
591 {
592     if (qemu_egl_display == EGL_NO_DISPLAY) {
593         return false;
594     }
595 
596     return epoxy_has_egl_extension(qemu_egl_display,
597                                    "EGL_EXT_image_dma_buf_import");
598 }
599 
600 EGLContext qemu_egl_init_ctx(void)
601 {
602     static const EGLint ctx_att_core[] = {
603         EGL_CONTEXT_OPENGL_PROFILE_MASK, EGL_CONTEXT_OPENGL_CORE_PROFILE_BIT,
604         EGL_NONE
605     };
606     static const EGLint ctx_att_gles[] = {
607         EGL_CONTEXT_CLIENT_VERSION, 2,
608         EGL_NONE
609     };
610     bool gles = (qemu_egl_mode == DISPLAYGL_MODE_ES);
611     EGLContext ectx;
612     EGLBoolean b;
613 
614     ectx = eglCreateContext(qemu_egl_display, qemu_egl_config, EGL_NO_CONTEXT,
615                             gles ? ctx_att_gles : ctx_att_core);
616     if (ectx == EGL_NO_CONTEXT) {
617         error_report("egl: eglCreateContext failed");
618         return NULL;
619     }
620 
621     b = eglMakeCurrent(qemu_egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE, ectx);
622     if (b == EGL_FALSE) {
623         error_report("egl: eglMakeCurrent failed");
624         return NULL;
625     }
626 
627     return ectx;
628 }
629 
630 bool egl_init(const char *rendernode, DisplayGLMode mode, Error **errp)
631 {
632     ERRP_GUARD();
633 
634     if (mode == DISPLAYGL_MODE_OFF) {
635         error_setg(errp, "egl: turning off GL doesn't make sense");
636         return false;
637     }
638 
639 #ifdef WIN32
640     if (qemu_egl_init_dpy_win32(EGL_DEFAULT_DISPLAY, mode) < 0) {
641         error_setg(errp, "egl: init failed");
642         return false;
643     }
644     qemu_egl_rn_ctx = qemu_egl_init_ctx();
645     if (!qemu_egl_rn_ctx) {
646         error_setg(errp, "egl: egl_init_ctx failed");
647         return false;
648     }
649 #elif defined(CONFIG_GBM)
650     if (egl_rendernode_init(rendernode, mode) < 0) {
651         error_setg(errp, "egl: render node init failed");
652         return false;
653     }
654 #endif
655 
656     if (!qemu_egl_rn_ctx) {
657         error_setg(errp, "egl: not available on this platform");
658         return false;
659     }
660 
661     display_opengl = 1;
662     return true;
663 }
664