1 #define GL_GLEXT_PROTOTYPES
6 #include <X11/extensions/Xcomposite.h>
7 #include <X11/extensions/Xdamage.h>
8 #include <X11/extensions/shape.h>
12 typedef struct CompositedWindow
26 typedef struct CompositedScreen
36 GLXContext glx_context;
39 unsigned geometry_loc;
40 unsigned vertex_buffer;
41 unsigned vertex_array;
42 CompositedWindow *windows;
44 unsigned windows_capacity;
47 typedef struct Compositor
50 CompositedScreen *screens;
53 PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribsARB;
54 PFNGLXBINDTEXIMAGEEXTPROC glXBindTexImageEXT;
55 PFNGLXRELEASETEXIMAGEEXTPROC glXReleaseTexImageEXT;
58 static const char *vshader =
60 "uniform vec4 geometry;\n"
62 "out vec2 texcoord;\n"
65 " gl_Position = vec4((geometry.xy+vertex*geometry.zw)*2.0-1.0, 0.0, 1.0);\n"
66 " texcoord = vec2(vertex.x, 1.0-vertex.y);\n"
69 static const char *fshader =
71 "uniform sampler2D window;\n"
73 "out vec4 frag_color;\n"
76 " frag_color = texture(window, texcoord);\n"
79 static const float vertices[] =
87 int with_error(const char *message)
89 fprintf(stderr, "%s\n", message);
93 int initialize_gl(Compositor *compositor, CompositedScreen *screen)
100 XSetWindowAttributes win_attr;
103 attribs[i++] = GLX_DRAWABLE_TYPE;
104 attribs[i++] = GLX_WINDOW_BIT;
105 attribs[i++] = GLX_RENDER_TYPE;
106 attribs[i++] = GLX_RGBA_BIT;
107 attribs[i++] = GLX_DOUBLEBUFFER;
109 attribs[i++] = GLX_BIND_TO_TEXTURE_RGBA_EXT;
113 configs = glXChooseFBConfig(compositor->display, screen->number, attribs, &nconfigs);
114 if(!configs || !nconfigs)
115 return with_error("Could not find a suitable FBConfig");
116 screen->fbconfig = configs[0];
119 vi = glXGetVisualFromFBConfig(compositor->display, screen->fbconfig);
120 win_attr.colormap = XCreateColormap(compositor->display, screen->root, vi->visual, AllocNone);
121 screen->render_window = XCreateWindow(compositor->display, screen->overlay, 0, 0, screen->width, screen->height, 0, vi->depth, InputOutput, vi->visual, CWColormap, &win_attr);
122 XMapWindow(compositor->display, screen->render_window);
124 screen->glx_window = glXCreateWindow(compositor->display, screen->fbconfig, screen->render_window, NULL);
127 attribs[i++] = GLX_CONTEXT_FLAGS_ARB;
128 attribs[i++] = GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
129 attribs[i++] = GLX_CONTEXT_MAJOR_VERSION_ARB;
131 attribs[i++] = GLX_CONTEXT_MINOR_VERSION_ARB;
135 screen->glx_context = compositor->glXCreateContextAttribsARB(compositor->display, screen->fbconfig, NULL, True, attribs);
142 void use_gl(Compositor *compositor, CompositedScreen *screen)
144 glXMakeContextCurrent(compositor->display, screen->glx_window, screen->glx_window, screen->glx_context);
147 unsigned compile_shader(GLenum type, const char *source)
154 shader = glCreateShader(type);
155 glShaderSource(shader, 1, &source, NULL);
156 glCompileShader(shader);
157 glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
158 glGetShaderInfoLog(shader, sizeof(info_log), &length, info_log);
161 fprintf(stderr, "Shader compilation failed:\n%s\n", info_log);
162 glDeleteShader(shader);
166 printf("Shader info log:\n%s\n", info_log);
171 int create_gl_resources(Compositor *compositor, CompositedScreen *screen)
177 use_gl(compositor, screen);
179 screen->shaders[0] = compile_shader(GL_VERTEX_SHADER, vshader);
180 screen->shaders[1] = compile_shader(GL_FRAGMENT_SHADER, fshader);
181 if(!screen->shaders[0] || !screen->shaders[1])
184 screen->program = glCreateProgram();
185 glAttachShader(screen->program, screen->shaders[0]);
186 glAttachShader(screen->program, screen->shaders[1]);
187 glBindAttribLocation(screen->program, 0, "vertex");
188 glLinkProgram(screen->program);
190 screen->geometry_loc = glGetUniformLocation(screen->program, "geometry");
192 glGetProgramiv(screen->program, GL_LINK_STATUS, &status);
193 glGetProgramInfoLog(screen->program, sizeof(info_log), &length, info_log);
196 fprintf(stderr, "Program link failed:\n%s\n", info_log);
197 glDeleteProgram(screen->program);
201 printf("Program info log:\n%s\n", info_log);
203 glGenBuffers(1, &screen->vertex_buffer);
204 glBindBuffer(GL_ARRAY_BUFFER, screen->vertex_buffer);
205 glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
207 glGenVertexArrays(1, &screen->vertex_array);
208 glBindVertexArray(screen->vertex_array);
209 glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, NULL);
210 glEnableVertexAttribArray(0);
212 glBindBuffer(GL_ARRAY_BUFFER, 0);
217 CompositedWindow *find_window(CompositedScreen *screen, Window w)
221 for(i=0; i<screen->nwindows; ++i)
222 if(screen->windows[i].window==w)
223 return &screen->windows[i];
228 void create_window_pixmap(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window)
235 glXDestroyPixmap(compositor->display, window->glx_pixmap);
236 XFreePixmap(compositor->display, window->pixmap);
240 attribs[i++] = GLX_TEXTURE_TARGET_EXT;
241 attribs[i++] = GLX_TEXTURE_2D_EXT;
242 attribs[i++] = GLX_TEXTURE_FORMAT_EXT;
243 attribs[i++] = GLX_TEXTURE_FORMAT_RGBA_EXT;
246 window->pixmap = XCompositeNameWindowPixmap(compositor->display, window->window);
247 window->glx_pixmap = glXCreatePixmap(compositor->display, screen->fbconfig, window->pixmap, attribs);
250 void add_window(Compositor *compositor, CompositedScreen *screen, Window w)
252 CompositedWindow *window;
253 XWindowAttributes win_attr;
255 if(w==screen->root || w==screen->overlay)
258 XGetWindowAttributes(compositor->display, w, &win_attr);
259 if(win_attr.class==InputOnly)
262 if(find_window(screen, w))
265 if(screen->nwindows==screen->windows_capacity)
267 screen->windows = (CompositedWindow *)realloc(screen->windows, (screen->windows_capacity+1)*sizeof(CompositedWindow));
268 ++screen->windows_capacity;
271 window = &screen->windows[screen->nwindows++];
274 window->x = win_attr.x;
275 window->y = win_attr.y;
276 window->width = win_attr.width;
277 window->height = win_attr.height;
278 window->map_state = win_attr.map_state;
280 window->damage = XDamageCreate(compositor->display, window->window, XDamageReportNonEmpty);
281 window->pixmap = None;
282 window->glx_pixmap = None;
284 XCompositeRedirectWindow(compositor->display, window->window, CompositeRedirectManual);
285 if(window->map_state==IsViewable)
286 create_window_pixmap(compositor, screen, window);
288 glGenTextures(1, &window->texture);
289 glBindTexture(GL_TEXTURE_2D, window->texture);
290 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
291 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
292 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
295 CompositedScreen *find_screen_by_root(Compositor *compositor, Window root)
299 for(i=0; i<compositor->nscreens; ++i)
300 if(compositor->screens[i].root==root)
301 return &compositor->screens[i];
306 int initialize_screen(Compositor *compositor, unsigned number)
308 CompositedScreen *screen;
309 const char *extensions;
319 screen = &compositor->screens[number];
320 screen->number = number;
322 extensions = glXQueryExtensionsString(compositor->display, screen->number);
323 if(!strstr(extensions, "GLX_ARB_create_context"))
324 return with_error("GLX_ARB_create_context is required");
325 if(!strstr(extensions, "GLX_EXT_texture_from_pixmap"))
326 return with_error("GLX_EXT_texture_from_pixmap is required");
328 screen->root = RootWindow(compositor->display, screen->number);
329 XSelectInput(compositor->display, screen->root, SubstructureNotifyMask);
330 screen->overlay = XCompositeGetOverlayWindow(compositor->display, screen->root);
331 XGetGeometry(compositor->display, screen->overlay, &dummy_root, &x, &y, &screen->width, &screen->height, &border, &depth);
332 XShapeCombineRectangles(compositor->display, screen->overlay, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted);
334 if(!initialize_gl(compositor, screen))
337 if(!create_gl_resources(compositor, screen))
340 XQueryTree(compositor->display, screen->root, &dummy_root, &dummy_parent, &children, &nchildren);
342 screen->windows = (CompositedWindow *)malloc(nchildren*sizeof(CompositedWindow));
343 screen->nwindows = 0;
344 screen->windows_capacity = nchildren;
346 for(i=0; i<nchildren; ++i)
347 add_window(compositor, screen, children[i]);
354 int initialize_compositor(Compositor *compositor)
362 compositor->display = XOpenDisplay(NULL);
363 if(!compositor->display)
364 return with_error("Could not open X display");
366 if(!XCompositeQueryExtension(compositor->display, &event_base, &error_base))
367 return with_error("XComposite is required but was not found");
368 else if(!XCompositeQueryVersion(compositor->display, &major_ver, &minor_ver))
369 return with_error("Cannot determine XComposite version");
370 else if(major_ver==0 && minor_ver<3)
371 return with_error("XComposite 0.3 or later is required");
373 if(!glXQueryExtension(compositor->display, &event_base, &error_base))
374 return with_error("GLX is required but was not found");
375 else if(!glXQueryVersion(compositor->display, &major_ver, &minor_ver))
376 return with_error("Cannot determine GLX version");
377 else if(major_ver<1 || (major_ver==1 && minor_ver<4))
378 return with_error("GLX 1.4 or later is required");
380 if(!XDamageQueryExtension(compositor->display, &compositor->damage_event, &error_base))
381 return with_error("XDamage is required but was not found");
382 else if(!XDamageQueryVersion(compositor->display, &major_ver, &minor_ver))
383 return with_error("Cannot determine XDamage version");
385 return with_error("XDamage 1.0 or later is required");
387 if(!XShapeQueryExtension(compositor->display, &event_base, &error_base))
388 return with_error("XShape is required but was not found");
389 else if(!XShapeQueryVersion(compositor->display, &major_ver, &minor_ver))
390 return with_error("Cannot determine XShape version");
391 else if(major_ver<1 || (major_ver==1 && minor_ver<1))
392 return with_error("XShape 1.1 or later is required");
394 compositor->glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((unsigned char *)"glXCreateContextAttribsARB");
395 compositor->glXBindTexImageEXT = (PFNGLXBINDTEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXBindTexImageEXT");
396 compositor->glXReleaseTexImageEXT = (PFNGLXRELEASETEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXReleaseTexImageEXT");
398 compositor->nscreens = ScreenCount(compositor->display);
399 compositor->screens = (CompositedScreen *)malloc(compositor->nscreens*sizeof(CompositedScreen));
400 for(i=0; i<compositor->nscreens; ++i)
401 if(!initialize_screen(compositor, i))
407 void shutdown_screen(Compositor *compositor, CompositedScreen *screen)
409 glXDestroyContext(compositor->display, screen->glx_context);
410 glXDestroyWindow(compositor->display, screen->glx_window);
411 XDestroyWindow(compositor->display, screen->render_window);
413 XCompositeReleaseOverlayWindow(compositor->display, screen->overlay);
416 void shutdown_compositor(Compositor *compositor)
420 glXMakeContextCurrent(compositor->display, 0, 0, NULL);
421 for(i=0; i<compositor->nscreens; ++i)
422 shutdown_screen(compositor, &compositor->screens[i]);
425 void process_create_window_event(Compositor *compositor, XCreateWindowEvent *event)
427 CompositedScreen *screen = find_screen_by_root(compositor, event->parent);
431 add_window(compositor, screen, event->window);
434 void process_map_event(Compositor *compositor, XMapEvent *event)
436 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
440 CompositedWindow *window = find_window(screen, event->window);
443 window->map_state = IsViewable;
444 create_window_pixmap(compositor, screen, window);
448 void process_unmap_event(Compositor *compositor, XUnmapEvent *event)
450 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
454 CompositedWindow *window = find_window(screen, event->window);
456 window->map_state = IsUnviewable;
459 void process_event(Compositor *compositor)
462 XNextEvent(compositor->display, &event);
466 process_create_window_event(compositor, &event.xcreatewindow);
469 process_map_event(compositor, &event.xmap);
472 process_unmap_event(compositor, &event.xunmap);
475 if(event.type!=compositor->damage_event+XDamageNotify)
476 printf("Event %d\n", event.type);
480 void refresh_screens(Compositor *compositor)
484 for(i=0; i<compositor->nscreens; ++i)
486 CompositedScreen *screen = &compositor->screens[i];
487 use_gl(compositor, screen);
489 glClearColor(0.5f, 0.5f, 0.5f, 0.0f);
490 glClear(GL_COLOR_BUFFER_BIT);
492 glUseProgram(screen->program);
493 glBindVertexArray(screen->vertex_array);
494 XGrabServer(compositor->display);
496 for(j=0; j<screen->nwindows; ++j)
498 CompositedWindow *window = &screen->windows[j];
499 if(window->map_state==IsViewable)
501 glBindTexture(GL_TEXTURE_2D, window->texture);
502 compositor->glXBindTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT, NULL);
503 glUniform4f(screen->geometry_loc, (float)window->x/screen->width, (float)(screen->height-window->y-window->height)/screen->height, (float)window->width/screen->width, (float)window->height/screen->height);
504 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
505 compositor->glXReleaseTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT);
506 XDamageSubtract(compositor->display, window->damage, None, None);
509 XUngrabServer(compositor->display);
510 glXSwapBuffers(compositor->display, screen->glx_window);
516 Compositor compositor;
518 if(!initialize_compositor(&compositor))
523 process_event(&compositor);
524 refresh_screens(&compositor);
527 shutdown_compositor(&compositor);