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
27 typedef struct CompositedScreen
37 GLXContext glx_context;
40 unsigned geometry_loc;
41 unsigned vertex_buffer;
42 unsigned vertex_array;
43 CompositedWindow *windows;
45 unsigned windows_capacity;
49 typedef struct Compositor
52 CompositedScreen *screens;
55 PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribsARB;
56 PFNGLXBINDTEXIMAGEEXTPROC glXBindTexImageEXT;
57 PFNGLXRELEASETEXIMAGEEXTPROC glXReleaseTexImageEXT;
61 static const char *vshader =
63 "uniform vec4 geometry;\n"
65 "out vec2 texcoord;\n"
68 " gl_Position = vec4((geometry.xy+vertex*geometry.zw)*2.0-1.0, 0.0, 1.0);\n"
69 " texcoord = vec2(vertex.x, 1.0-vertex.y);\n"
72 static const char *fshader =
74 "uniform sampler2D window;\n"
76 "out vec4 frag_color;\n"
79 " frag_color = texture(window, texcoord);\n"
82 static const float vertices[] =
90 int with_error(const char *message)
92 fprintf(stderr, "%s\n", message);
96 int initialize_gl(Compositor *compositor, CompositedScreen *screen)
100 GLXFBConfig *configs;
103 XSetWindowAttributes win_attr;
106 attribs[i++] = GLX_DRAWABLE_TYPE;
107 attribs[i++] = GLX_WINDOW_BIT;
108 attribs[i++] = GLX_RENDER_TYPE;
109 attribs[i++] = GLX_RGBA_BIT;
110 attribs[i++] = GLX_DOUBLEBUFFER;
112 attribs[i++] = GLX_BIND_TO_TEXTURE_RGBA_EXT;
116 configs = glXChooseFBConfig(compositor->display, screen->number, attribs, &nconfigs);
117 if(!configs || !nconfigs)
118 return with_error("Could not find a suitable FBConfig");
119 screen->fbconfig = configs[0];
122 vi = glXGetVisualFromFBConfig(compositor->display, screen->fbconfig);
123 win_attr.colormap = XCreateColormap(compositor->display, screen->root, vi->visual, AllocNone);
124 screen->render_window = XCreateWindow(compositor->display, screen->overlay, 0, 0, screen->width, screen->height, 0, vi->depth, InputOutput, vi->visual, CWColormap, &win_attr);
125 XMapWindow(compositor->display, screen->render_window);
127 screen->glx_window = glXCreateWindow(compositor->display, screen->fbconfig, screen->render_window, NULL);
130 attribs[i++] = GLX_CONTEXT_FLAGS_ARB;
131 attribs[i++] = GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
132 attribs[i++] = GLX_CONTEXT_MAJOR_VERSION_ARB;
134 attribs[i++] = GLX_CONTEXT_MINOR_VERSION_ARB;
138 screen->glx_context = compositor->glXCreateContextAttribsARB(compositor->display, screen->fbconfig, NULL, True, attribs);
145 void use_gl(Compositor *compositor, CompositedScreen *screen)
147 glXMakeContextCurrent(compositor->display, screen->glx_window, screen->glx_window, screen->glx_context);
150 unsigned compile_shader(GLenum type, const char *source)
157 shader = glCreateShader(type);
158 glShaderSource(shader, 1, &source, NULL);
159 glCompileShader(shader);
160 glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
161 glGetShaderInfoLog(shader, sizeof(info_log), &length, info_log);
164 fprintf(stderr, "Shader compilation failed:\n%s\n", info_log);
165 glDeleteShader(shader);
169 printf("Shader info log:\n%s\n", info_log);
174 int create_gl_resources(Compositor *compositor, CompositedScreen *screen)
180 use_gl(compositor, screen);
182 screen->shaders[0] = compile_shader(GL_VERTEX_SHADER, vshader);
183 screen->shaders[1] = compile_shader(GL_FRAGMENT_SHADER, fshader);
184 if(!screen->shaders[0] || !screen->shaders[1])
187 screen->program = glCreateProgram();
188 glAttachShader(screen->program, screen->shaders[0]);
189 glAttachShader(screen->program, screen->shaders[1]);
190 glBindAttribLocation(screen->program, 0, "vertex");
191 glLinkProgram(screen->program);
193 screen->geometry_loc = glGetUniformLocation(screen->program, "geometry");
195 glGetProgramiv(screen->program, GL_LINK_STATUS, &status);
196 glGetProgramInfoLog(screen->program, sizeof(info_log), &length, info_log);
199 fprintf(stderr, "Program link failed:\n%s\n", info_log);
200 glDeleteProgram(screen->program);
204 printf("Program info log:\n%s\n", info_log);
206 glGenBuffers(1, &screen->vertex_buffer);
207 glBindBuffer(GL_ARRAY_BUFFER, screen->vertex_buffer);
208 glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
210 glGenVertexArrays(1, &screen->vertex_array);
211 glBindVertexArray(screen->vertex_array);
212 glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, NULL);
213 glEnableVertexAttribArray(0);
215 glBindBuffer(GL_ARRAY_BUFFER, 0);
220 CompositedWindow *find_window(CompositedScreen *screen, Window w)
224 for(i=0; i<screen->nwindows; ++i)
225 if(screen->windows[i].window==w)
226 return &screen->windows[i];
231 void create_window_pixmap(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window)
238 glXDestroyPixmap(compositor->display, window->glx_pixmap);
239 XFreePixmap(compositor->display, window->pixmap);
243 attribs[i++] = GLX_TEXTURE_TARGET_EXT;
244 attribs[i++] = GLX_TEXTURE_2D_EXT;
245 attribs[i++] = GLX_TEXTURE_FORMAT_EXT;
246 attribs[i++] = GLX_TEXTURE_FORMAT_RGBA_EXT;
249 window->pixmap = XCompositeNameWindowPixmap(compositor->display, window->window);
250 window->glx_pixmap = glXCreatePixmap(compositor->display, screen->fbconfig, window->pixmap, attribs);
253 void add_window(Compositor *compositor, CompositedScreen *screen, Window w)
255 CompositedWindow *window;
256 XWindowAttributes win_attr;
258 if(w==screen->root || w==screen->overlay)
261 XGetWindowAttributes(compositor->display, w, &win_attr);
262 if(win_attr.class==InputOnly)
265 if(find_window(screen, w))
268 if(screen->nwindows==screen->windows_capacity)
270 screen->windows = (CompositedWindow *)realloc(screen->windows, (screen->windows_capacity+1)*sizeof(CompositedWindow));
271 ++screen->windows_capacity;
274 window = &screen->windows[screen->nwindows++];
277 window->x = win_attr.x;
278 window->y = win_attr.y;
279 window->width = win_attr.width;
280 window->height = win_attr.height;
281 window->border = win_attr.border_width;
282 window->map_state = win_attr.map_state;
284 window->damage = XDamageCreate(compositor->display, window->window, XDamageReportNonEmpty);
285 window->pixmap = None;
286 window->glx_pixmap = None;
288 XCompositeRedirectWindow(compositor->display, window->window, CompositeRedirectManual);
289 if(window->map_state==IsViewable)
290 create_window_pixmap(compositor, screen, window);
292 glGenTextures(1, &window->texture);
293 glBindTexture(GL_TEXTURE_2D, window->texture);
294 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
295 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
296 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
299 CompositedScreen *find_screen_by_root(Compositor *compositor, Window root)
303 for(i=0; i<compositor->nscreens; ++i)
304 if(compositor->screens[i].root==root)
305 return &compositor->screens[i];
310 CompositedScreen *find_screen_by_window(Compositor *compositor, Window w)
314 for(i=0; i<compositor->nscreens; ++i)
315 for(j=0; j<compositor->screens[i].nwindows; ++j)
316 if(compositor->screens[i].windows[j].window==w)
317 return &compositor->screens[i];
322 int initialize_screen(Compositor *compositor, unsigned number)
324 CompositedScreen *screen;
325 const char *extensions;
335 screen = &compositor->screens[number];
336 screen->number = number;
338 extensions = glXQueryExtensionsString(compositor->display, screen->number);
339 if(!strstr(extensions, "GLX_ARB_create_context"))
340 return with_error("GLX_ARB_create_context is required");
341 if(!strstr(extensions, "GLX_EXT_texture_from_pixmap"))
342 return with_error("GLX_EXT_texture_from_pixmap is required");
344 screen->root = RootWindow(compositor->display, screen->number);
345 XSelectInput(compositor->display, screen->root, SubstructureNotifyMask);
346 screen->overlay = XCompositeGetOverlayWindow(compositor->display, screen->root);
347 XGetGeometry(compositor->display, screen->overlay, &dummy_root, &x, &y, &screen->width, &screen->height, &border, &depth);
348 XShapeCombineRectangles(compositor->display, screen->overlay, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted);
350 if(!initialize_gl(compositor, screen))
353 if(!create_gl_resources(compositor, screen))
356 XQueryTree(compositor->display, screen->root, &dummy_root, &dummy_parent, &children, &nchildren);
358 screen->windows = (CompositedWindow *)malloc(nchildren*sizeof(CompositedWindow));
359 screen->nwindows = 0;
360 screen->windows_capacity = nchildren;
362 for(i=0; i<nchildren; ++i)
363 add_window(compositor, screen, children[i]);
370 int initialize_compositor(Compositor *compositor)
378 compositor->display = XOpenDisplay(NULL);
379 if(!compositor->display)
380 return with_error("Could not open X display");
382 if(!XCompositeQueryExtension(compositor->display, &event_base, &error_base))
383 return with_error("XComposite is required but was not found");
384 else if(!XCompositeQueryVersion(compositor->display, &major_ver, &minor_ver))
385 return with_error("Cannot determine XComposite version");
386 else if(major_ver==0 && minor_ver<3)
387 return with_error("XComposite 0.3 or later is required");
389 if(!glXQueryExtension(compositor->display, &event_base, &error_base))
390 return with_error("GLX is required but was not found");
391 else if(!glXQueryVersion(compositor->display, &major_ver, &minor_ver))
392 return with_error("Cannot determine GLX version");
393 else if(major_ver<1 || (major_ver==1 && minor_ver<4))
394 return with_error("GLX 1.4 or later is required");
396 if(!XDamageQueryExtension(compositor->display, &compositor->damage_event, &error_base))
397 return with_error("XDamage is required but was not found");
398 else if(!XDamageQueryVersion(compositor->display, &major_ver, &minor_ver))
399 return with_error("Cannot determine XDamage version");
401 return with_error("XDamage 1.0 or later is required");
403 if(!XShapeQueryExtension(compositor->display, &event_base, &error_base))
404 return with_error("XShape is required but was not found");
405 else if(!XShapeQueryVersion(compositor->display, &major_ver, &minor_ver))
406 return with_error("Cannot determine XShape version");
407 else if(major_ver<1 || (major_ver==1 && minor_ver<1))
408 return with_error("XShape 1.1 or later is required");
410 compositor->glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((unsigned char *)"glXCreateContextAttribsARB");
411 compositor->glXBindTexImageEXT = (PFNGLXBINDTEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXBindTexImageEXT");
412 compositor->glXReleaseTexImageEXT = (PFNGLXRELEASETEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXReleaseTexImageEXT");
414 compositor->nscreens = ScreenCount(compositor->display);
415 compositor->screens = (CompositedScreen *)malloc(compositor->nscreens*sizeof(CompositedScreen));
416 for(i=0; i<compositor->nscreens; ++i)
417 if(!initialize_screen(compositor, i))
423 void shutdown_screen(Compositor *compositor, CompositedScreen *screen)
425 glXDestroyContext(compositor->display, screen->glx_context);
426 glXDestroyWindow(compositor->display, screen->glx_window);
427 XDestroyWindow(compositor->display, screen->render_window);
429 XCompositeReleaseOverlayWindow(compositor->display, screen->overlay);
432 void shutdown_compositor(Compositor *compositor)
436 glXMakeContextCurrent(compositor->display, 0, 0, NULL);
437 for(i=0; i<compositor->nscreens; ++i)
438 shutdown_screen(compositor, &compositor->screens[i]);
441 void process_create_window_event(Compositor *compositor, XCreateWindowEvent *event)
443 CompositedScreen *screen = find_screen_by_root(compositor, event->parent);
447 add_window(compositor, screen, event->window);
450 void process_map_event(Compositor *compositor, XMapEvent *event)
452 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
456 CompositedWindow *window = find_window(screen, event->window);
459 window->map_state = IsViewable;
460 create_window_pixmap(compositor, screen, window);
464 void process_unmap_event(Compositor *compositor, XUnmapEvent *event)
466 CompositedScreen *screen = find_screen_by_root(compositor, event->event);
470 CompositedWindow *window = find_window(screen, event->window);
472 window->map_state = IsUnviewable;
475 void process_damage_event(Compositor *compositor, XDamageNotifyEvent *event)
477 CompositedScreen *screen = find_screen_by_window(compositor, event->drawable);
482 compositor->dirty = 1;
485 int process_event(Compositor *compositor)
488 if(compositor->dirty)
490 if(!XCheckMaskEvent(compositor->display, -1, &event))
494 XNextEvent(compositor->display, &event);
499 process_create_window_event(compositor, &event.xcreatewindow);
502 process_map_event(compositor, &event.xmap);
505 process_unmap_event(compositor, &event.xunmap);
508 if(event.type==compositor->damage_event+XDamageNotify)
509 process_damage_event(compositor, (XDamageNotifyEvent *)&event);
511 printf("Event %d\n", event.type);
517 void refresh_screens(Compositor *compositor)
521 for(i=0; i<compositor->nscreens; ++i)
523 CompositedScreen *screen = &compositor->screens[i];
524 use_gl(compositor, screen);
526 glClearColor(0.5f, 0.5f, 0.5f, 0.0f);
527 glClear(GL_COLOR_BUFFER_BIT);
529 glUseProgram(screen->program);
530 glBindVertexArray(screen->vertex_array);
531 for(j=0; j<screen->nwindows; ++j)
533 CompositedWindow *window = &screen->windows[j];
534 if(window->map_state==IsViewable)
536 glBindTexture(GL_TEXTURE_2D, window->texture);
537 compositor->glXBindTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT, NULL);
538 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);
539 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
540 compositor->glXReleaseTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT);
541 XDamageSubtract(compositor->display, window->damage, None, None);
544 glXSwapBuffers(compositor->display, screen->glx_window);
549 compositor->dirty = 0;
554 Compositor compositor;
556 if(!initialize_compositor(&compositor))
561 if(!process_event(&compositor))
562 refresh_screens(&compositor);
565 shutdown_compositor(&compositor);