1 #define GL_GLEXT_PROTOTYPES
7 #include <X11/extensions/Xcomposite.h>
8 #include <X11/extensions/Xdamage.h>
9 #include <X11/extensions/shape.h>
13 typedef struct CompositedWindow
28 typedef struct CompositedScreen
38 GLXContext glx_context;
41 unsigned geometry_loc;
42 unsigned vertex_buffer;
43 unsigned vertex_array;
44 CompositedWindow *windows;
46 unsigned windows_capacity;
50 typedef struct Compositor
53 CompositedScreen *screens;
56 PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribsARB;
57 PFNGLXBINDTEXIMAGEEXTPROC glXBindTexImageEXT;
58 PFNGLXRELEASETEXIMAGEEXTPROC glXReleaseTexImageEXT;
62 static const char *vshader =
64 "uniform vec4 geometry;\n"
66 "out vec2 texcoord;\n"
69 " gl_Position = vec4((geometry.xy+vertex*geometry.zw)*2.0-1.0, 0.0, 1.0);\n"
70 " texcoord = vec2(vertex.x, 1.0-vertex.y);\n"
73 static const char *fshader =
75 "uniform sampler2D window;\n"
77 "out vec4 frag_color;\n"
80 " frag_color = texture(window, texcoord);\n"
83 static const float vertices[] =
91 int terminate_requested = 0;
93 int x_error_handler(Display *display, XErrorEvent *event)
95 printf("Ignoring X error %d on resource %lx\n", event->error_code, event->resourceid);
100 int with_error(const char *message)
102 fprintf(stderr, "%s\n", message);
106 int initialize_gl(Compositor *compositor, CompositedScreen *screen)
110 GLXFBConfig *configs;
113 XSetWindowAttributes win_attr;
116 attribs[i++] = GLX_DRAWABLE_TYPE;
117 attribs[i++] = GLX_WINDOW_BIT;
118 attribs[i++] = GLX_RENDER_TYPE;
119 attribs[i++] = GLX_RGBA_BIT;
120 attribs[i++] = GLX_DOUBLEBUFFER;
122 attribs[i++] = GLX_BIND_TO_TEXTURE_RGBA_EXT;
126 configs = glXChooseFBConfig(compositor->display, screen->number, attribs, &nconfigs);
127 if(!configs || !nconfigs)
128 return with_error("Could not find a suitable FBConfig");
129 screen->fbconfig = configs[0];
132 vi = glXGetVisualFromFBConfig(compositor->display, screen->fbconfig);
133 win_attr.colormap = XCreateColormap(compositor->display, screen->root, vi->visual, AllocNone);
134 screen->render_window = XCreateWindow(compositor->display, screen->overlay, 0, 0, screen->width, screen->height, 0, vi->depth, InputOutput, vi->visual, CWColormap, &win_attr);
135 XMapWindow(compositor->display, screen->render_window);
137 screen->glx_window = glXCreateWindow(compositor->display, screen->fbconfig, screen->render_window, NULL);
140 attribs[i++] = GLX_CONTEXT_FLAGS_ARB;
141 attribs[i++] = GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
142 attribs[i++] = GLX_CONTEXT_MAJOR_VERSION_ARB;
144 attribs[i++] = GLX_CONTEXT_MINOR_VERSION_ARB;
148 screen->glx_context = compositor->glXCreateContextAttribsARB(compositor->display, screen->fbconfig, NULL, True, attribs);
155 void use_gl(Compositor *compositor, CompositedScreen *screen)
157 glXMakeContextCurrent(compositor->display, screen->glx_window, screen->glx_window, screen->glx_context);
160 unsigned compile_shader(GLenum type, const char *source)
167 shader = glCreateShader(type);
168 glShaderSource(shader, 1, &source, NULL);
169 glCompileShader(shader);
170 glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
171 glGetShaderInfoLog(shader, sizeof(info_log), &length, info_log);
174 fprintf(stderr, "Shader compilation failed:\n%s\n", info_log);
175 glDeleteShader(shader);
179 printf("Shader info log:\n%s\n", info_log);
184 int create_gl_resources(Compositor *compositor, CompositedScreen *screen)
190 use_gl(compositor, screen);
192 screen->shaders[0] = compile_shader(GL_VERTEX_SHADER, vshader);
193 screen->shaders[1] = compile_shader(GL_FRAGMENT_SHADER, fshader);
194 if(!screen->shaders[0] || !screen->shaders[1])
197 screen->program = glCreateProgram();
198 glAttachShader(screen->program, screen->shaders[0]);
199 glAttachShader(screen->program, screen->shaders[1]);
200 glBindAttribLocation(screen->program, 0, "vertex");
201 glLinkProgram(screen->program);
203 screen->geometry_loc = glGetUniformLocation(screen->program, "geometry");
205 glGetProgramiv(screen->program, GL_LINK_STATUS, &status);
206 glGetProgramInfoLog(screen->program, sizeof(info_log), &length, info_log);
209 fprintf(stderr, "Program link failed:\n%s\n", info_log);
210 glDeleteProgram(screen->program);
214 printf("Program info log:\n%s\n", info_log);
216 glGenBuffers(1, &screen->vertex_buffer);
217 glBindBuffer(GL_ARRAY_BUFFER, screen->vertex_buffer);
218 glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
220 glGenVertexArrays(1, &screen->vertex_array);
221 glBindVertexArray(screen->vertex_array);
222 glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, NULL);
223 glEnableVertexAttribArray(0);
225 glBindBuffer(GL_ARRAY_BUFFER, 0);
230 CompositedWindow *find_window(CompositedScreen *screen, Window w)
234 for(i=0; i<screen->nwindows; ++i)
235 if(screen->windows[i].window==w)
236 return &screen->windows[i];
241 void create_window_pixmap(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window)
248 glXDestroyPixmap(compositor->display, window->glx_pixmap);
249 XFreePixmap(compositor->display, window->pixmap);
253 attribs[i++] = GLX_TEXTURE_TARGET_EXT;
254 attribs[i++] = GLX_TEXTURE_2D_EXT;
255 attribs[i++] = GLX_TEXTURE_FORMAT_EXT;
256 attribs[i++] = GLX_TEXTURE_FORMAT_RGBA_EXT;
259 window->pixmap = XCompositeNameWindowPixmap(compositor->display, window->window);
260 window->glx_pixmap = glXCreatePixmap(compositor->display, screen->fbconfig, window->pixmap, attribs);
263 CompositedWindow *add_window(Compositor *compositor, CompositedScreen *screen, Window w)
265 CompositedWindow *window;
266 XWindowAttributes win_attr;
268 if(w==screen->root || w==screen->overlay)
271 if(!XGetWindowAttributes(compositor->display, w, &win_attr))
273 printf("XGetWindowAttributes failed; probably the window was already destroyed\n");
276 if(win_attr.class==InputOnly)
279 if(find_window(screen, w))
282 if(screen->nwindows==screen->windows_capacity)
284 screen->windows = (CompositedWindow *)realloc(screen->windows, (screen->windows_capacity+1)*sizeof(CompositedWindow));
285 ++screen->windows_capacity;
288 window = &screen->windows[screen->nwindows++];
291 window->x = win_attr.x;
292 window->y = win_attr.y;
293 window->width = win_attr.width;
294 window->height = win_attr.height;
295 window->border = win_attr.border_width;
296 window->map_state = win_attr.map_state;
298 window->damage = XDamageCreate(compositor->display, window->window, XDamageReportNonEmpty);
299 window->pixmap = None;
300 window->glx_pixmap = None;
302 XCompositeRedirectWindow(compositor->display, window->window, CompositeRedirectManual);
303 if(window->map_state==IsViewable)
304 create_window_pixmap(compositor, screen, window);
306 glGenTextures(1, &window->texture);
307 glBindTexture(GL_TEXTURE_2D, window->texture);
308 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
309 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
310 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
315 void remove_window(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window, int destroyed)
319 glDeleteTextures(1, &window->texture);
322 XDamageDestroy(compositor->display, window->damage);
325 glXDestroyPixmap(compositor->display, window->glx_pixmap);
326 XFreePixmap(compositor->display, window->pixmap);
328 XCompositeUnredirectWindow(compositor->display, window->window, CompositeRedirectManual);
332 for(i=window-screen->windows; i<screen->nwindows; ++i)
333 screen->windows[i] = screen->windows[i+1];
336 CompositedWindow *reorder_window(CompositedScreen *screen, CompositedWindow *window, Window above)
339 CompositedWindow hold;
341 i = window-screen->windows;
344 for(j=0; j<screen->nwindows; ++j)
345 if(screen->windows[j].window==above)
348 if(j>=screen->nwindows || i==j+1)
361 screen->windows[i] = screen->windows[i+1];
366 screen->windows[i] = screen->windows[i-1];
368 screen->windows[j] = hold;
370 return &screen->windows[j];
373 CompositedScreen *find_screen_by_root(Compositor *compositor, Window root)
377 for(i=0; i<compositor->nscreens; ++i)
378 if(compositor->screens[i].root==root)
379 return &compositor->screens[i];
384 CompositedScreen *find_screen_by_window(Compositor *compositor, Window w)
388 for(i=0; i<compositor->nscreens; ++i)
389 for(j=0; j<compositor->screens[i].nwindows; ++j)
390 if(compositor->screens[i].windows[j].window==w)
391 return &compositor->screens[i];
396 int initialize_screen(Compositor *compositor, unsigned number)
398 CompositedScreen *screen;
399 const char *extensions;
409 screen = &compositor->screens[number];
410 screen->number = number;
412 extensions = glXQueryExtensionsString(compositor->display, screen->number);
413 if(!strstr(extensions, "GLX_ARB_create_context"))
414 return with_error("GLX_ARB_create_context is required");
415 if(!strstr(extensions, "GLX_EXT_texture_from_pixmap"))
416 return with_error("GLX_EXT_texture_from_pixmap is required");
418 screen->root = RootWindow(compositor->display, screen->number);
419 XSelectInput(compositor->display, screen->root, SubstructureNotifyMask);
420 screen->overlay = XCompositeGetOverlayWindow(compositor->display, screen->root);
421 XGetGeometry(compositor->display, screen->overlay, &dummy_root, &x, &y, &screen->width, &screen->height, &border, &depth);
422 XShapeCombineRectangles(compositor->display, screen->overlay, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted);
424 if(!initialize_gl(compositor, screen))
427 if(!create_gl_resources(compositor, screen))
430 XQueryTree(compositor->display, screen->root, &dummy_root, &dummy_parent, &children, &nchildren);
432 screen->windows = (CompositedWindow *)malloc(nchildren*sizeof(CompositedWindow));
433 screen->nwindows = 0;
434 screen->windows_capacity = nchildren;
436 for(i=0; i<nchildren; ++i)
437 add_window(compositor, screen, children[i]);
446 int initialize_compositor(Compositor *compositor)
454 compositor->display = XOpenDisplay(NULL);
455 if(!compositor->display)
456 return with_error("Could not open X display");
458 XSetErrorHandler(&x_error_handler);
460 if(!XCompositeQueryExtension(compositor->display, &event_base, &error_base))
461 return with_error("XComposite is required but was not found");
462 else if(!XCompositeQueryVersion(compositor->display, &major_ver, &minor_ver))
463 return with_error("Cannot determine XComposite version");
464 else if(major_ver==0 && minor_ver<3)
465 return with_error("XComposite 0.3 or later is required");
467 if(!glXQueryExtension(compositor->display, &event_base, &error_base))
468 return with_error("GLX is required but was not found");
469 else if(!glXQueryVersion(compositor->display, &major_ver, &minor_ver))
470 return with_error("Cannot determine GLX version");
471 else if(major_ver<1 || (major_ver==1 && minor_ver<4))
472 return with_error("GLX 1.4 or later is required");
474 if(!XDamageQueryExtension(compositor->display, &compositor->damage_event, &error_base))
475 return with_error("XDamage is required but was not found");
476 else if(!XDamageQueryVersion(compositor->display, &major_ver, &minor_ver))
477 return with_error("Cannot determine XDamage version");
479 return with_error("XDamage 1.0 or later is required");
481 if(!XShapeQueryExtension(compositor->display, &event_base, &error_base))
482 return with_error("XShape is required but was not found");
483 else if(!XShapeQueryVersion(compositor->display, &major_ver, &minor_ver))
484 return with_error("Cannot determine XShape version");
485 else if(major_ver<1 || (major_ver==1 && minor_ver<1))
486 return with_error("XShape 1.1 or later is required");
488 compositor->glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((unsigned char *)"glXCreateContextAttribsARB");
489 compositor->glXBindTexImageEXT = (PFNGLXBINDTEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXBindTexImageEXT");
490 compositor->glXReleaseTexImageEXT = (PFNGLXRELEASETEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXReleaseTexImageEXT");
492 compositor->nscreens = ScreenCount(compositor->display);
493 compositor->screens = (CompositedScreen *)malloc(compositor->nscreens*sizeof(CompositedScreen));
494 for(i=0; i<compositor->nscreens; ++i)
495 if(!initialize_screen(compositor, i))
498 compositor->dirty = 1;
503 void shutdown_screen(Compositor *compositor, CompositedScreen *screen)
507 use_gl(compositor, screen);
509 for(i=0; i<screen->nwindows; ++i)
511 glDeleteTextures(1, &screen->windows[i].texture);
512 if(screen->windows[i].pixmap)
514 glXDestroyPixmap(compositor->display, screen->windows[i].glx_pixmap);
515 XFreePixmap(compositor->display, screen->windows[i].pixmap);
516 XDamageDestroy(compositor->display, screen->windows[i].damage);
520 glXMakeContextCurrent(compositor->display, 0, 0, NULL);
521 glXDestroyContext(compositor->display, screen->glx_context);
522 glXDestroyWindow(compositor->display, screen->glx_window);
523 XDestroyWindow(compositor->display, screen->render_window);
525 XCompositeReleaseOverlayWindow(compositor->display, screen->overlay);
527 free(screen->windows);
530 void shutdown_compositor(Compositor *compositor)
534 for(i=0; i<compositor->nscreens; ++i)
535 shutdown_screen(compositor, &compositor->screens[i]);
536 free(compositor->screens);
538 XCloseDisplay(compositor->display);
541 void mark_dirty(Compositor *compositor, CompositedScreen *screen)
543 compositor->dirty = 1;
547 void process_create_window_event(Compositor *compositor, XCreateWindowEvent *event)
549 CompositedScreen *screen = find_screen_by_root(compositor, event->parent);
553 add_window(compositor, screen, event->window);
556 void process_destroy_window_event(Compositor *compositor, XDestroyWindowEvent *event)
558 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
562 CompositedWindow *window = find_window(screen, event->window);
564 remove_window(compositor, screen, window, 1);
567 void process_map_event(Compositor *compositor, XMapEvent *event)
569 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
573 CompositedWindow *window = find_window(screen, event->window);
577 window->map_state = IsViewable;
578 create_window_pixmap(compositor, screen, window);
580 mark_dirty(compositor, screen);
583 void process_unmap_event(Compositor *compositor, XUnmapEvent *event)
585 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
589 CompositedWindow *window = find_window(screen, event->window);
591 window->map_state = IsUnviewable;
593 mark_dirty(compositor, screen);
596 void process_reparent_event(Compositor *compositor, XReparentEvent *event)
598 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
602 CompositedWindow *window;
603 if(event->parent==screen->root)
604 window = add_window(compositor, screen, event->window);
607 window = find_window(screen, event->window);
611 remove_window(compositor, screen, window, 0);
614 if(window && window->map_state==IsViewable)
615 mark_dirty(compositor, screen);
618 void process_configure_event(Compositor *compositor, XConfigureEvent *event)
620 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
624 CompositedWindow *window = find_window(screen, event->window);
628 window->x = event->x;
629 window->y = event->y;
630 if((unsigned)event->width!=window->width || (unsigned)event->height!=window->height || (unsigned)event->border_width!=window->border)
632 window->width = event->width;
633 window->height = event->height;
634 window->border = event->border_width;
635 create_window_pixmap(compositor, screen, window);
637 reorder_window(screen, window, event->above);
639 if(window->map_state==IsViewable)
640 mark_dirty(compositor, screen);
643 void process_damage_event(Compositor *compositor, XDamageNotifyEvent *event)
645 CompositedScreen *screen = find_screen_by_window(compositor, event->drawable);
649 CompositedWindow *window = find_window(screen, event->drawable);
650 if(window->map_state==IsViewable)
651 mark_dirty(compositor, screen);
654 int process_event(Compositor *compositor)
657 if(compositor->dirty)
659 if(!XCheckMaskEvent(compositor->display, -1, &event))
663 XNextEvent(compositor->display, &event);
668 process_create_window_event(compositor, &event.xcreatewindow);
671 process_destroy_window_event(compositor, &event.xdestroywindow);
674 process_map_event(compositor, &event.xmap);
677 process_unmap_event(compositor, &event.xunmap);
680 process_reparent_event(compositor, &event.xreparent);
682 case ConfigureNotify:
683 process_configure_event(compositor, &event.xconfigure);
686 if(event.type==compositor->damage_event+XDamageNotify)
687 process_damage_event(compositor, (XDamageNotifyEvent *)&event);
689 printf("Event %d\n", event.type);
695 void refresh_screens(Compositor *compositor)
699 for(i=0; i<compositor->nscreens; ++i)
701 CompositedScreen *screen = &compositor->screens[i];
705 use_gl(compositor, screen);
707 glClearColor(0.5f, 0.5f, 0.5f, 0.0f);
708 glClear(GL_COLOR_BUFFER_BIT);
710 glUseProgram(screen->program);
711 glBindVertexArray(screen->vertex_array);
712 for(j=0; j<screen->nwindows; ++j)
714 CompositedWindow *window = &screen->windows[j];
715 if(window->map_state==IsViewable)
717 glBindTexture(GL_TEXTURE_2D, window->texture);
718 compositor->glXBindTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT, NULL);
719 glUniform4f(screen->geometry_loc, (float)window->x/screen->width, (float)(screen->height-window->y-window->height)/screen->height, (float)(window->width+2*window->border)/screen->width, (float)(window->height+2*window->border)/screen->height);
720 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
721 compositor->glXReleaseTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT);
722 XDamageSubtract(compositor->display, window->damage, None, None);
725 glXSwapBuffers(compositor->display, screen->glx_window);
730 compositor->dirty = 0;
733 void sighandler(int sig)
735 terminate_requested = 1;
741 Compositor compositor;
743 signal(SIGINT, &sighandler);
744 signal(SIGTERM, &sighandler);
746 if(!initialize_compositor(&compositor))
749 while(!terminate_requested)
751 if(!process_event(&compositor))
752 refresh_screens(&compositor);
755 shutdown_compositor(&compositor);