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 void 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);
313 CompositedScreen *find_screen_by_root(Compositor *compositor, Window root)
317 for(i=0; i<compositor->nscreens; ++i)
318 if(compositor->screens[i].root==root)
319 return &compositor->screens[i];
324 CompositedScreen *find_screen_by_window(Compositor *compositor, Window w)
328 for(i=0; i<compositor->nscreens; ++i)
329 for(j=0; j<compositor->screens[i].nwindows; ++j)
330 if(compositor->screens[i].windows[j].window==w)
331 return &compositor->screens[i];
336 int initialize_screen(Compositor *compositor, unsigned number)
338 CompositedScreen *screen;
339 const char *extensions;
349 screen = &compositor->screens[number];
350 screen->number = number;
352 extensions = glXQueryExtensionsString(compositor->display, screen->number);
353 if(!strstr(extensions, "GLX_ARB_create_context"))
354 return with_error("GLX_ARB_create_context is required");
355 if(!strstr(extensions, "GLX_EXT_texture_from_pixmap"))
356 return with_error("GLX_EXT_texture_from_pixmap is required");
358 screen->root = RootWindow(compositor->display, screen->number);
359 XSelectInput(compositor->display, screen->root, SubstructureNotifyMask);
360 screen->overlay = XCompositeGetOverlayWindow(compositor->display, screen->root);
361 XGetGeometry(compositor->display, screen->overlay, &dummy_root, &x, &y, &screen->width, &screen->height, &border, &depth);
362 XShapeCombineRectangles(compositor->display, screen->overlay, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted);
364 if(!initialize_gl(compositor, screen))
367 if(!create_gl_resources(compositor, screen))
370 XQueryTree(compositor->display, screen->root, &dummy_root, &dummy_parent, &children, &nchildren);
372 screen->windows = (CompositedWindow *)malloc(nchildren*sizeof(CompositedWindow));
373 screen->nwindows = 0;
374 screen->windows_capacity = nchildren;
376 for(i=0; i<nchildren; ++i)
377 add_window(compositor, screen, children[i]);
386 int initialize_compositor(Compositor *compositor)
394 compositor->display = XOpenDisplay(NULL);
395 if(!compositor->display)
396 return with_error("Could not open X display");
398 XSetErrorHandler(&x_error_handler);
400 if(!XCompositeQueryExtension(compositor->display, &event_base, &error_base))
401 return with_error("XComposite is required but was not found");
402 else if(!XCompositeQueryVersion(compositor->display, &major_ver, &minor_ver))
403 return with_error("Cannot determine XComposite version");
404 else if(major_ver==0 && minor_ver<3)
405 return with_error("XComposite 0.3 or later is required");
407 if(!glXQueryExtension(compositor->display, &event_base, &error_base))
408 return with_error("GLX is required but was not found");
409 else if(!glXQueryVersion(compositor->display, &major_ver, &minor_ver))
410 return with_error("Cannot determine GLX version");
411 else if(major_ver<1 || (major_ver==1 && minor_ver<4))
412 return with_error("GLX 1.4 or later is required");
414 if(!XDamageQueryExtension(compositor->display, &compositor->damage_event, &error_base))
415 return with_error("XDamage is required but was not found");
416 else if(!XDamageQueryVersion(compositor->display, &major_ver, &minor_ver))
417 return with_error("Cannot determine XDamage version");
419 return with_error("XDamage 1.0 or later is required");
421 if(!XShapeQueryExtension(compositor->display, &event_base, &error_base))
422 return with_error("XShape is required but was not found");
423 else if(!XShapeQueryVersion(compositor->display, &major_ver, &minor_ver))
424 return with_error("Cannot determine XShape version");
425 else if(major_ver<1 || (major_ver==1 && minor_ver<1))
426 return with_error("XShape 1.1 or later is required");
428 compositor->glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((unsigned char *)"glXCreateContextAttribsARB");
429 compositor->glXBindTexImageEXT = (PFNGLXBINDTEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXBindTexImageEXT");
430 compositor->glXReleaseTexImageEXT = (PFNGLXRELEASETEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXReleaseTexImageEXT");
432 compositor->nscreens = ScreenCount(compositor->display);
433 compositor->screens = (CompositedScreen *)malloc(compositor->nscreens*sizeof(CompositedScreen));
434 for(i=0; i<compositor->nscreens; ++i)
435 if(!initialize_screen(compositor, i))
438 compositor->dirty = 1;
443 void shutdown_screen(Compositor *compositor, CompositedScreen *screen)
447 use_gl(compositor, screen);
449 for(i=0; i<screen->nwindows; ++i)
451 glDeleteTextures(1, &screen->windows[i].texture);
452 if(screen->windows[i].pixmap)
454 glXDestroyPixmap(compositor->display, screen->windows[i].glx_pixmap);
455 XFreePixmap(compositor->display, screen->windows[i].pixmap);
456 XDamageDestroy(compositor->display, screen->windows[i].damage);
460 glXMakeContextCurrent(compositor->display, 0, 0, NULL);
461 glXDestroyContext(compositor->display, screen->glx_context);
462 glXDestroyWindow(compositor->display, screen->glx_window);
463 XDestroyWindow(compositor->display, screen->render_window);
465 XCompositeReleaseOverlayWindow(compositor->display, screen->overlay);
467 free(screen->windows);
470 void shutdown_compositor(Compositor *compositor)
474 for(i=0; i<compositor->nscreens; ++i)
475 shutdown_screen(compositor, &compositor->screens[i]);
476 free(compositor->screens);
478 XCloseDisplay(compositor->display);
481 void process_create_window_event(Compositor *compositor, XCreateWindowEvent *event)
483 CompositedScreen *screen = find_screen_by_root(compositor, event->parent);
487 add_window(compositor, screen, event->window);
490 void process_map_event(Compositor *compositor, XMapEvent *event)
492 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
496 CompositedWindow *window = find_window(screen, event->window);
499 window->map_state = IsViewable;
500 create_window_pixmap(compositor, screen, window);
504 void process_unmap_event(Compositor *compositor, XUnmapEvent *event)
506 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
510 CompositedWindow *window = find_window(screen, event->window);
512 window->map_state = IsUnviewable;
515 void process_damage_event(Compositor *compositor, XDamageNotifyEvent *event)
517 CompositedScreen *screen = find_screen_by_window(compositor, event->drawable);
522 compositor->dirty = 1;
525 int process_event(Compositor *compositor)
528 if(compositor->dirty)
530 if(!XCheckMaskEvent(compositor->display, -1, &event))
534 XNextEvent(compositor->display, &event);
539 process_create_window_event(compositor, &event.xcreatewindow);
542 process_map_event(compositor, &event.xmap);
545 process_unmap_event(compositor, &event.xunmap);
548 if(event.type==compositor->damage_event+XDamageNotify)
549 process_damage_event(compositor, (XDamageNotifyEvent *)&event);
551 printf("Event %d\n", event.type);
557 void refresh_screens(Compositor *compositor)
561 for(i=0; i<compositor->nscreens; ++i)
563 CompositedScreen *screen = &compositor->screens[i];
564 use_gl(compositor, screen);
566 glClearColor(0.5f, 0.5f, 0.5f, 0.0f);
567 glClear(GL_COLOR_BUFFER_BIT);
569 glUseProgram(screen->program);
570 glBindVertexArray(screen->vertex_array);
571 for(j=0; j<screen->nwindows; ++j)
573 CompositedWindow *window = &screen->windows[j];
574 if(window->map_state==IsViewable)
576 glBindTexture(GL_TEXTURE_2D, window->texture);
577 compositor->glXBindTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT, NULL);
578 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);
579 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
580 compositor->glXReleaseTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT);
581 XDamageSubtract(compositor->display, window->damage, None, None);
584 glXSwapBuffers(compositor->display, screen->glx_window);
589 compositor->dirty = 0;
592 void sighandler(int sig)
594 terminate_requested = 1;
600 Compositor compositor;
602 signal(SIGINT, &sighandler);
603 signal(SIGTERM, &sighandler);
605 if(!initialize_compositor(&compositor))
608 while(!terminate_requested)
610 if(!process_event(&compositor))
611 refresh_screens(&compositor);
614 shutdown_compositor(&compositor);