source/main.c

   1 #define GL_GLEXT_PROTOTYPES
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <signal.h>
   6 #include <X11/Xlib.h>
   7 #include <X11/extensions/Xcomposite.h>
   8 #include <X11/extensions/Xdamage.h>
   9 #include <X11/extensions/shape.h>
  10 #include <X11/extensions/Xrandr.h>
  11 #include <GL/gl.h>
  12 #include <GL/glx.h>
  13
  14 typedef struct CompositedWindow
  15 {
  16         Window window;
  17         int x;
  18         int y;
  19         unsigned width;
  20         unsigned height;
  21         unsigned border;
  22         int map_state;
  23         Damage damage;
  24         Pixmap pixmap;
  25         GLXPixmap glx_pixmap;
  26         unsigned texture;
  27 } CompositedWindow;
  28
  29 typedef struct CompositedMonitor
  30 {
  31         int enabled;
  32         int x;
  33         int y;
  34         unsigned width;
  35         unsigned height;
  36         unsigned vertex_buffer;
  37         unsigned index_buffer;
  38         unsigned vertex_array;
  39         unsigned tessellation;
  40         unsigned nelements;
  41 } CompositedMonitor;
  42
  43 typedef struct CompositedScreen
  44 {
  45         int number;
  46         Window root;
  47         unsigned width;
  48         unsigned height;
  49         Window overlay;
  50         Window render_window;
  51         GLXFBConfig fbconfig;
  52         GLXWindow glx_window;
  53         GLXContext glx_context;
  54         unsigned shaders[2];
  55         unsigned program;
  56         unsigned geometry_loc;
  57         unsigned window_vertex_buffer;
  58         unsigned window_vertex_array;
  59         unsigned framebuffer;
  60         unsigned fb_texture;
  61         CompositedWindow *windows;
  62         unsigned nwindows;
  63         unsigned windows_capacity;
  64         CompositedMonitor *monitors;
  65         unsigned nmonitors;
  66         int dirty;
  67 } CompositedScreen;
  68
  69 typedef struct Compositor
  70 {
  71         Display *display;
  72         CompositedScreen *screens;
  73         unsigned nscreens;
  74         int damage_event;
  75         PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribsARB;
  76         PFNGLXBINDTEXIMAGEEXTPROC glXBindTexImageEXT;
  77         PFNGLXRELEASETEXIMAGEEXTPROC glXReleaseTexImageEXT;
  78         int dirty;
  79 } Compositor;
  80
  81 static const char *vshader =
  82         "#version 150\n"
  83         "uniform vec4 geometry;\n"
  84         "in vec2 vertex;\n"
  85         "in vec2 texture_coord;\n"
  86         "out vec2 texcoord;\n"
  87         "void main()\n"
  88         "{\n"
  89         "  gl_Position = vec4((geometry.xy+vertex*geometry.zw)*2.0-1.0, 0.0, 1.0);\n"
  90         "  texcoord = texture_coord;\n"
  91         "}\n";
  92
  93 static const char *fshader =
  94         "#version 150\n"
  95         "uniform sampler2D image;\n"
  96         "in vec2 texcoord;\n"
  97         "out vec4 frag_color;\n"
  98         "void main()\n"
  99         "{\n"
 100         "       frag_color = texture(image, texcoord);\n"
 101         "}\n";
 102
 103 static const float window_vertices[] =
 104 {
 105         /* vertex    texcoord */
 106         0.0f, 1.0f,  0.0f, 0.0f,
 107         0.0f, 0.0f,  0.0f, 1.0f,
 108         1.0f, 1.0f,  1.0f, 0.0f,
 109         1.0f, 0.0f,  1.0f, 1.0f
 110 };
 111
 112 int terminate_requested = 0;
 113
 114 int x_error_handler(Display *display, XErrorEvent *event)
 115 {
 116         printf("Ignoring X error %d on resource %lx\n", event->error_code, event->resourceid);
 117         (void)display;
 118         return 0;
 119 }
 120
 121 int with_error(const char *message)
 122 {
 123         fprintf(stderr, "%s\n", message);
 124         return 0;
 125 }
 126
 127 int initialize_gl(Compositor *compositor, CompositedScreen *screen)
 128 {
 129         int attribs[9];
 130         unsigned i;
 131         GLXFBConfig *configs;
 132         int nconfigs;
 133         XVisualInfo *vi;
 134         XSetWindowAttributes win_attr;
 135
 136         i = 0;
 137         attribs[i++] = GLX_DRAWABLE_TYPE;
 138         attribs[i++] = GLX_WINDOW_BIT;
 139         attribs[i++] = GLX_RENDER_TYPE;
 140         attribs[i++] = GLX_RGBA_BIT;
 141         attribs[i++] = GLX_DOUBLEBUFFER;
 142         attribs[i++] = True;
 143         attribs[i++] = GLX_BIND_TO_TEXTURE_RGBA_EXT;
 144         attribs[i++] = True;
 145         attribs[i] = None;
 146
 147         configs = glXChooseFBConfig(compositor->display, screen->number, attribs, &nconfigs);
 148         if(!configs || !nconfigs)
 149                 return with_error("Could not find a suitable FBConfig");
 150         screen->fbconfig = configs[0];
 151         XFree(configs);
 152
 153         vi = glXGetVisualFromFBConfig(compositor->display, screen->fbconfig);
 154         win_attr.colormap = XCreateColormap(compositor->display, screen->root, vi->visual, AllocNone);
 155         screen->render_window = XCreateWindow(compositor->display, screen->overlay, 0, 0, screen->width, screen->height, 0, vi->depth, InputOutput, vi->visual, CWColormap, &win_attr);
 156         XMapWindow(compositor->display, screen->render_window);
 157
 158         screen->glx_window = glXCreateWindow(compositor->display, screen->fbconfig, screen->render_window, NULL);
 159
 160         i = 0;
 161         attribs[i++] = GLX_CONTEXT_FLAGS_ARB;
 162         attribs[i++] = GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
 163         attribs[i++] = GLX_CONTEXT_MAJOR_VERSION_ARB;
 164         attribs[i++] = 3;
 165         attribs[i++] = GLX_CONTEXT_MINOR_VERSION_ARB;
 166         attribs[i++] = 1;
 167         attribs[i] = None;
 168
 169         screen->glx_context = compositor->glXCreateContextAttribsARB(compositor->display, screen->fbconfig, NULL, True, attribs);
 170
 171         XFree(vi);
 172
 173         return 1;
 174 }
 175
 176 void use_gl(Compositor *compositor, CompositedScreen *screen)
 177 {
 178         glXMakeContextCurrent(compositor->display, screen->glx_window, screen->glx_window, screen->glx_context);
 179 }
 180
 181 unsigned compile_shader(GLenum type, const char *source)
 182 {
 183         unsigned shader;
 184         int status;
 185         char info_log[1024];
 186         GLsizei length;
 187
 188         shader = glCreateShader(type);
 189         glShaderSource(shader, 1, &source, NULL);
 190         glCompileShader(shader);
 191         glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
 192         glGetShaderInfoLog(shader, sizeof(info_log), &length, info_log);
 193         if(!status)
 194         {
 195                 fprintf(stderr, "Shader compilation failed:\n%s\n", info_log);
 196                 glDeleteShader(shader);
 197                 return 0;
 198         }
 199         else if(length)
 200                 printf("Shader info log:\n%s\n", info_log);
 201
 202         return shader;
 203 }
 204
 205 unsigned link_program(unsigned *shaders, unsigned nshaders)
 206 {
 207         unsigned program;
 208         unsigned i;
 209         int status;
 210         char info_log[1024];
 211         GLsizei length;
 212
 213         program = glCreateProgram();
 214         for(i=0; i<nshaders; ++i)
 215                 glAttachShader(program, shaders[i]);
 216         glBindAttribLocation(program, 0, "vertex");
 217         glBindAttribLocation(program, 1, "texture_coord");
 218         glBindFragDataLocation(program, 0, "frag_color");
 219         glLinkProgram(program);
 220
 221         glGetProgramiv(program, GL_LINK_STATUS, &status);
 222         glGetProgramInfoLog(program, sizeof(info_log), &length, info_log);
 223         if(!status)
 224         {
 225                 fprintf(stderr, "Program link failed:\n%s\n", info_log);
 226                 glDeleteProgram(program);
 227                 return 0;
 228         }
 229         else if(length)
 230                 printf("Program info log:\n%s\n", info_log);
 231
 232         return program;
 233 }
 234
 235 int create_gl_resources(Compositor *compositor, CompositedScreen *screen)
 236 {
 237         unsigned stride;
 238
 239         use_gl(compositor, screen);
 240
 241         screen->shaders[0] = compile_shader(GL_VERTEX_SHADER, vshader);
 242         screen->shaders[1] = compile_shader(GL_FRAGMENT_SHADER, fshader);
 243         if(!screen->shaders[0] || !screen->shaders[1])
 244                 return 0;
 245
 246         screen->program = link_program(screen->shaders, 2);
 247         if(!screen->program)
 248                 return 0;
 249
 250         screen->geometry_loc = glGetUniformLocation(screen->program, "geometry");
 251
 252         glGenBuffers(1, &screen->window_vertex_buffer);
 253         glBindBuffer(GL_ARRAY_BUFFER, screen->window_vertex_buffer);
 254         glBufferData(GL_ARRAY_BUFFER, sizeof(window_vertices), window_vertices, GL_STATIC_DRAW);
 255
 256         stride = 4*sizeof(float);
 257         glGenVertexArrays(1, &screen->window_vertex_array);
 258         glBindVertexArray(screen->window_vertex_array);
 259         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, stride, NULL);
 260         glEnableVertexAttribArray(0);
 261         glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, (void *)(2*sizeof(float)));
 262         glEnableVertexAttribArray(1);
 263         glBindVertexArray(0);
 264
 265         glBindBuffer(GL_ARRAY_BUFFER, 0);
 266
 267         glGenTextures(1, &screen->fb_texture);
 268         glBindTexture(GL_TEXTURE_2D, screen->fb_texture);
 269         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, screen->width, screen->height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
 270         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 271         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 272         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 273         glBindTexture(GL_TEXTURE_2D, 0);
 274
 275         glGenFramebuffers(1, &screen->framebuffer);
 276         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, screen->framebuffer);
 277         glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, screen->fb_texture, 0);
 278         glDepthMask(GL_FALSE);
 279         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 280
 281         return 1;
 282 }
 283
 284 CompositedWindow *find_window(CompositedScreen *screen, Window w)
 285 {
 286         unsigned i;
 287
 288         for(i=0; i<screen->nwindows; ++i)
 289                 if(screen->windows[i].window==w)
 290                         return &screen->windows[i];
 291
 292         return NULL;
 293 }
 294
 295 void create_window_pixmap(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window)
 296 {
 297         int attribs[5];
 298         unsigned i;
 299
 300         if(window->pixmap)
 301         {
 302                 glXDestroyPixmap(compositor->display, window->glx_pixmap);
 303                 XFreePixmap(compositor->display, window->pixmap);
 304         }
 305
 306         i = 0;
 307         attribs[i++] = GLX_TEXTURE_TARGET_EXT;
 308         attribs[i++] = GLX_TEXTURE_2D_EXT;
 309         attribs[i++] = GLX_TEXTURE_FORMAT_EXT;
 310         attribs[i++] = GLX_TEXTURE_FORMAT_RGBA_EXT;
 311         attribs[i++] = None;
 312
 313         window->pixmap = XCompositeNameWindowPixmap(compositor->display, window->window);
 314         window->glx_pixmap = glXCreatePixmap(compositor->display, screen->fbconfig, window->pixmap, attribs);
 315 }
 316
 317 CompositedWindow *add_window(Compositor *compositor, CompositedScreen *screen, Window w)
 318 {
 319         CompositedWindow *window;
 320         XWindowAttributes win_attr;
 321
 322         if(w==screen->root || w==screen->overlay)
 323                 return NULL;
 324
 325         if(!XGetWindowAttributes(compositor->display, w, &win_attr))
 326         {
 327                 printf("XGetWindowAttributes failed; probably the window was already destroyed\n");
 328                 return NULL;
 329         }
 330         if(win_attr.class==InputOnly)
 331                 return NULL;
 332
 333         if(find_window(screen, w))
 334                 return NULL;
 335
 336         if(screen->nwindows==screen->windows_capacity)
 337         {
 338                 screen->windows = (CompositedWindow *)realloc(screen->windows, (screen->windows_capacity+1)*sizeof(CompositedWindow));
 339                 ++screen->windows_capacity;
 340         }
 341
 342         window = &screen->windows[screen->nwindows++];
 343
 344         window->window = w;
 345         window->x = win_attr.x;
 346         window->y = win_attr.y;
 347         window->width = win_attr.width;
 348         window->height = win_attr.height;
 349         window->border = win_attr.border_width;
 350         window->map_state = win_attr.map_state;
 351
 352         window->damage = XDamageCreate(compositor->display, window->window, XDamageReportNonEmpty);
 353         window->pixmap = None;
 354         window->glx_pixmap = None;
 355
 356         XCompositeRedirectWindow(compositor->display, window->window, CompositeRedirectManual);
 357         if(window->map_state==IsViewable)
 358                 create_window_pixmap(compositor, screen, window);
 359
 360         glGenTextures(1, &window->texture);
 361         glBindTexture(GL_TEXTURE_2D, window->texture);
 362         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 363         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 364         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 365
 366         return window;
 367 }
 368
 369 void remove_window(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window, int destroyed)
 370 {
 371         unsigned i;
 372
 373         glDeleteTextures(1, &window->texture);
 374         if(!destroyed)
 375         {
 376                 XDamageDestroy(compositor->display, window->damage);
 377                 if(window->pixmap)
 378                 {
 379                         glXDestroyPixmap(compositor->display, window->glx_pixmap);
 380                         XFreePixmap(compositor->display, window->pixmap);
 381                 }
 382                 XCompositeUnredirectWindow(compositor->display, window->window, CompositeRedirectManual);
 383         }
 384
 385         --screen->nwindows;
 386         for(i=window-screen->windows; i<screen->nwindows; ++i)
 387                 screen->windows[i] = screen->windows[i+1];
 388 }
 389
 390 CompositedWindow *reorder_window(CompositedScreen *screen, CompositedWindow *window, Window above)
 391 {
 392         unsigned i, j;
 393         CompositedWindow hold;
 394
 395         i = window-screen->windows;
 396         if(above)
 397         {
 398                 for(j=0; j<screen->nwindows; ++j)
 399                         if(screen->windows[j].window==above)
 400                                 break;
 401
 402                 if(j>=screen->nwindows || i==j+1)
 403                         return window;
 404
 405                 if(j<i)
 406                         ++j;
 407         }
 408         else
 409                 j = 0;
 410
 411         hold = *window;
 412         if(i<j)
 413         {
 414                 for(; i<j; ++i)
 415                         screen->windows[i] = screen->windows[i+1];
 416         }
 417         else
 418         {
 419                 for(; i>j; --i)
 420                         screen->windows[i] = screen->windows[i-1];
 421         }
 422         screen->windows[j] = hold;
 423
 424         return &screen->windows[j];
 425 }
 426
 427 CompositedScreen *find_screen_by_root(Compositor *compositor, Window root)
 428 {
 429         unsigned i;
 430
 431         for(i=0; i<compositor->nscreens; ++i)
 432                 if(compositor->screens[i].root==root)
 433                         return &compositor->screens[i];
 434
 435         return NULL;
 436 }
 437
 438 CompositedScreen *find_screen_by_window(Compositor *compositor, Window w)
 439 {
 440         unsigned i, j;
 441
 442         for(i=0; i<compositor->nscreens; ++i)
 443                 for(j=0; j<compositor->screens[i].nwindows; ++j)
 444                         if(compositor->screens[i].windows[j].window==w)
 445                                 return &compositor->screens[i];
 446
 447         return NULL;
 448 }
 449
 450 void update_monitor_vertices(CompositedScreen *screen, CompositedMonitor *monitor)
 451 {
 452         unsigned t;
 453         unsigned data_size;
 454         float *vertex_data;
 455         unsigned short *index_data;
 456         unsigned x, y;
 457         unsigned i;
 458
 459         t = monitor->tessellation;
 460
 461         data_size = (t+1)*(t+1)*4*sizeof(float);
 462         vertex_data = (float *)malloc(data_size);
 463         for(y=0; y<=t; ++y)
 464                 for(x=0; x<=t; ++x)
 465                 {
 466                         float xf, yf;
 467                         float *v;
 468
 469                         xf = (float)x/t;
 470                         yf = (float)y/t;
 471                         v = vertex_data+(y*(t+1)+x)*4;
 472                         v[0] = xf;
 473                         v[1] = yf;
 474                         v[2] = (monitor->x+xf*monitor->width)/screen->width;
 475                         v[3] = (monitor->y+yf*monitor->height)/screen->height;
 476                 }
 477         glBindBuffer(GL_ARRAY_BUFFER, monitor->vertex_buffer);
 478         glBufferData(GL_ARRAY_BUFFER, data_size, vertex_data, GL_STATIC_DRAW);
 479         glBindBuffer(GL_ARRAY_BUFFER, 0);
 480         free(vertex_data);
 481
 482         monitor->nelements = t*((t+1)*2+1)-1;
 483         data_size = monitor->nelements*sizeof(unsigned short);
 484         index_data = (unsigned short *)malloc(data_size);
 485         i = 0;
 486         for(y=0; y<t; ++y)
 487         {
 488                 if(y>0)
 489                         index_data[i++] = 0xFFFF;
 490                 for(x=0; x<=t; ++x)
 491                 {
 492                         index_data[i++] = (y+1)*(t+1)+x;
 493                         index_data[i++] = y*(t+1)+x;
 494                 }
 495         }
 496         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, monitor->index_buffer);
 497         glBufferData(GL_ELEMENT_ARRAY_BUFFER, data_size, index_data, GL_STATIC_DRAW);
 498         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 499         free(index_data);
 500 }
 501
 502 int initialize_monitor(Compositor *compositor, CompositedScreen *screen, CompositedMonitor *monitor, XRRScreenResources *xrr_res, unsigned index)
 503 {
 504         XRROutputInfo *output;
 505         XRRCrtcInfo *crtc;
 506         unsigned buffers[2];
 507         unsigned stride;
 508
 509         output = XRRGetOutputInfo(compositor->display, xrr_res, xrr_res->outputs[index]);
 510         monitor->enabled = !!output->crtc;
 511         if(!monitor->enabled)
 512         {
 513                 XRRFreeOutputInfo(output);
 514                 return 1;
 515         }
 516
 517         crtc = XRRGetCrtcInfo(compositor->display, xrr_res, output->crtc);
 518         monitor->x = crtc->x;
 519         monitor->y = crtc->y;
 520         monitor->width = crtc->width;
 521         monitor->height = crtc->height;
 522         XRRFreeCrtcInfo(crtc);
 523         XRRFreeOutputInfo(output);
 524
 525         glGenBuffers(2, buffers);
 526         monitor->vertex_buffer = buffers[0];
 527         monitor->index_buffer = buffers[1];
 528
 529         monitor->tessellation = 20;
 530         update_monitor_vertices(screen, monitor);
 531         stride = 4*sizeof(float);
 532
 533         glGenVertexArrays(1, &monitor->vertex_array);
 534         glBindVertexArray(monitor->vertex_array);
 535         glBindBuffer(GL_ARRAY_BUFFER, monitor->vertex_buffer);
 536         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, stride, NULL);
 537         glEnableVertexAttribArray(0);
 538         glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, (void *)(2*sizeof(float)));
 539         glEnableVertexAttribArray(1);
 540         glBindBuffer(GL_ARRAY_BUFFER, 0);
 541         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, monitor->index_buffer);
 542         glBindVertexArray(0);
 543
 544         return 1;
 545 }
 546
 547 int initialize_screen(Compositor *compositor, unsigned number)
 548 {
 549         CompositedScreen *screen;
 550         const char *extensions;
 551         Window dummy_root;
 552         int x, y;
 553         unsigned border;
 554         unsigned depth;
 555         XRRScreenResources *xrr_res;
 556         Window dummy_parent;
 557         Window *children;
 558         unsigned nchildren;
 559         unsigned i;
 560
 561         screen = &compositor->screens[number];
 562         screen->number = number;
 563
 564         extensions = glXQueryExtensionsString(compositor->display, screen->number);
 565         if(!strstr(extensions, "GLX_ARB_create_context"))
 566                 return with_error("GLX_ARB_create_context is required");
 567         if(!strstr(extensions, "GLX_EXT_texture_from_pixmap"))
 568                 return with_error("GLX_EXT_texture_from_pixmap is required");
 569
 570         screen->root = RootWindow(compositor->display, screen->number);
 571         XSelectInput(compositor->display, screen->root, SubstructureNotifyMask);
 572         screen->overlay = XCompositeGetOverlayWindow(compositor->display, screen->root);
 573         XGetGeometry(compositor->display, screen->overlay, &dummy_root, &x, &y, &screen->width, &screen->height, &border, &depth);
 574         XShapeCombineRectangles(compositor->display, screen->overlay, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted);
 575
 576         if(!initialize_gl(compositor, screen))
 577                 return 0;
 578
 579         if(!create_gl_resources(compositor, screen))
 580                 return 0;
 581
 582         xrr_res = XRRGetScreenResources(compositor->display, screen->root);
 583         screen->nmonitors = xrr_res->noutput;
 584         screen->monitors = (CompositedMonitor *)malloc(screen->nmonitors*sizeof(CompositedMonitor));
 585         for(i=0; i<screen->nmonitors; ++i)
 586                 if(!initialize_monitor(compositor, screen, &screen->monitors[i], xrr_res, i))
 587                         return 0;
 588         XRRFreeScreenResources(xrr_res);
 589
 590         XQueryTree(compositor->display, screen->root, &dummy_root, &dummy_parent, &children, &nchildren);
 591
 592         screen->windows = (CompositedWindow *)malloc(nchildren*sizeof(CompositedWindow));
 593         screen->nwindows = 0;
 594         screen->windows_capacity = nchildren;
 595
 596         for(i=0; i<nchildren; ++i)
 597                 add_window(compositor, screen, children[i]);
 598
 599         XFree(children);
 600
 601         screen->dirty = 1;
 602
 603         return 1;
 604 }
 605
 606 int initialize_compositor(Compositor *compositor)
 607 {
 608         int event_base;
 609         int error_base;
 610         int major_ver;
 611         int minor_ver;
 612         unsigned i;
 613
 614         compositor->display = XOpenDisplay(NULL);
 615         if(!compositor->display)
 616                 return with_error("Could not open X display");
 617
 618         XSetErrorHandler(&x_error_handler);
 619
 620         if(!XCompositeQueryExtension(compositor->display, &event_base, &error_base))
 621                 return with_error("XComposite is required but was not found");
 622         else if(!XCompositeQueryVersion(compositor->display, &major_ver, &minor_ver))
 623                 return with_error("Cannot determine XComposite version");
 624         else if(major_ver==0 && minor_ver<3)
 625                 return with_error("XComposite 0.3 or later is required");
 626
 627         if(!glXQueryExtension(compositor->display, &event_base, &error_base))
 628                 return with_error("GLX is required but was not found");
 629         else if(!glXQueryVersion(compositor->display, &major_ver, &minor_ver))
 630                 return with_error("Cannot determine GLX version");
 631         else if(major_ver<1 || (major_ver==1 && minor_ver<4))
 632                 return with_error("GLX 1.4 or later is required");
 633
 634         if(!XDamageQueryExtension(compositor->display, &compositor->damage_event, &error_base))
 635                 return with_error("XDamage is required but was not found");
 636         else if(!XDamageQueryVersion(compositor->display, &major_ver, &minor_ver))
 637                 return with_error("Cannot determine XDamage version");
 638         else if(major_ver<1)
 639                 return with_error("XDamage 1.0 or later is required");
 640
 641         if(!XShapeQueryExtension(compositor->display, &event_base, &error_base))
 642                 return with_error("XShape is required but was not found");
 643         else if(!XShapeQueryVersion(compositor->display, &major_ver, &minor_ver))
 644                 return with_error("Cannot determine XShape version");
 645         else if(major_ver<1 || (major_ver==1 && minor_ver<1))
 646                 return with_error("XShape 1.1 or later is required");
 647
 648         if(!XRRQueryExtension(compositor->display, &event_base, &error_base))
 649                 return with_error("XRandR is required but was not found");
 650         else if(!XRRQueryVersion(compositor->display, &major_ver, &minor_ver))
 651                 return with_error("Cannot determine XRandR version");
 652         else if(major_ver<1 || (major_ver==1 && minor_ver<2))
 653                 return with_error("XRandR 1.2 or later is required");
 654
 655         compositor->glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((unsigned char *)"glXCreateContextAttribsARB");
 656         compositor->glXBindTexImageEXT = (PFNGLXBINDTEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXBindTexImageEXT");
 657         compositor->glXReleaseTexImageEXT = (PFNGLXRELEASETEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXReleaseTexImageEXT");
 658
 659         compositor->nscreens = ScreenCount(compositor->display);
 660         compositor->screens = (CompositedScreen *)malloc(compositor->nscreens*sizeof(CompositedScreen));
 661         for(i=0; i<compositor->nscreens; ++i)
 662                 if(!initialize_screen(compositor, i))
 663                         return 0;
 664
 665         compositor->dirty = 1;
 666
 667         return 1;
 668 }
 669
 670 void shutdown_screen(Compositor *compositor, CompositedScreen *screen)
 671 {
 672         unsigned i;
 673
 674         use_gl(compositor, screen);
 675
 676         for(i=0; i<screen->nwindows; ++i)
 677         {
 678                 glDeleteTextures(1, &screen->windows[i].texture);
 679                 if(screen->windows[i].pixmap)
 680                 {
 681                         glXDestroyPixmap(compositor->display, screen->windows[i].glx_pixmap);
 682                         XFreePixmap(compositor->display, screen->windows[i].pixmap);
 683                         XDamageDestroy(compositor->display, screen->windows[i].damage);
 684                 }
 685         }
 686
 687         for(i=0; i<screen->nmonitors; ++i)
 688                 if(screen->monitors[i].enabled)
 689                 {
 690                         glDeleteBuffers(1, &screen->monitors[i].vertex_buffer);
 691                         glDeleteBuffers(1, &screen->monitors[i].index_buffer);
 692                         glDeleteVertexArrays(1, &screen->monitors[i].vertex_array);
 693                 }
 694
 695         glDeleteBuffers(1, &screen->window_vertex_buffer);
 696         glDeleteVertexArrays(1, &screen->window_vertex_array);
 697         glDeleteFramebuffers(1, &screen->framebuffer);
 698         glDeleteTextures(1, &screen->fb_texture);
 699         glDeleteProgram(screen->program);
 700         glDeleteShader(screen->shaders[0]);
 701         glDeleteShader(screen->shaders[1]);
 702
 703         glXMakeContextCurrent(compositor->display, 0, 0, NULL);
 704         glXDestroyContext(compositor->display, screen->glx_context);
 705         glXDestroyWindow(compositor->display, screen->glx_window);
 706         XDestroyWindow(compositor->display, screen->render_window);
 707
 708         XCompositeReleaseOverlayWindow(compositor->display, screen->overlay);
 709
 710         free(screen->windows);
 711         free(screen->monitors);
 712 }
 713
 714 void shutdown_compositor(Compositor *compositor)
 715 {
 716         unsigned i;
 717
 718         for(i=0; i<compositor->nscreens; ++i)
 719                 shutdown_screen(compositor, &compositor->screens[i]);
 720         free(compositor->screens);
 721
 722         XCloseDisplay(compositor->display);
 723 }
 724
 725 void mark_dirty(Compositor *compositor, CompositedScreen *screen)
 726 {
 727         compositor->dirty = 1;
 728         screen->dirty = 1;
 729 }
 730
 731 void process_create_window_event(Compositor *compositor, XCreateWindowEvent *event)
 732 {
 733         CompositedScreen *screen;
 734
 735         if((screen = find_screen_by_root(compositor, event->parent)))
 736                 add_window(compositor, screen, event->window);
 737 }
 738
 739 void process_destroy_window_event(Compositor *compositor, XDestroyWindowEvent *event)
 740 {
 741         CompositedScreen *screen;
 742         CompositedWindow *window;
 743
 744         if((screen = find_screen_by_root(compositor, event->event)))
 745                 if((window = find_window(screen, event->window)))
 746                         remove_window(compositor, screen, window, 1);
 747 }
 748
 749 void process_map_event(Compositor *compositor, XMapEvent *event)
 750 {
 751         CompositedScreen *screen;
 752         CompositedWindow *window;
 753
 754         screen = find_screen_by_root(compositor, event->event);
 755         if(!screen)
 756                 return;
 757
 758         window = find_window(screen, event->window);
 759         if(!window)
 760                 return;
 761
 762         window->map_state = IsViewable;
 763         create_window_pixmap(compositor, screen, window);
 764
 765         mark_dirty(compositor, screen);
 766 }
 767
 768 void process_unmap_event(Compositor *compositor, XUnmapEvent *event)
 769 {
 770         CompositedScreen *screen;
 771         CompositedWindow *window;
 772
 773         screen = find_screen_by_root(compositor, event->event);
 774         if(!screen)
 775                 return;
 776
 777         window = find_window(screen, event->window);
 778         if(window)
 779                 window->map_state = IsUnviewable;
 780
 781         mark_dirty(compositor, screen);
 782 }
 783
 784 void process_reparent_event(Compositor *compositor, XReparentEvent *event)
 785 {
 786         CompositedScreen *screen;
 787         CompositedWindow *window;
 788
 789         screen = find_screen_by_root(compositor, event->event);
 790         if(!screen)
 791                 return;
 792
 793         if(event->parent==screen->root)
 794                 window = add_window(compositor, screen, event->window);
 795         else
 796         {
 797                 window = find_window(screen, event->window);
 798                 if(!window)
 799                         return;
 800
 801                 remove_window(compositor, screen, window, 0);
 802         }
 803
 804         if(window && window->map_state==IsViewable)
 805                 mark_dirty(compositor, screen);
 806 }
 807
 808 void process_configure_event(Compositor *compositor, XConfigureEvent *event)
 809 {
 810         CompositedScreen *screen;
 811         CompositedWindow *window;
 812
 813         screen = find_screen_by_root(compositor, event->event);
 814         if(!screen)
 815                 return;
 816
 817         window = find_window(screen, event->window);
 818         if(!window)
 819                 return;
 820
 821         window->x = event->x;
 822         window->y = event->y;
 823         if((unsigned)event->width!=window->width || (unsigned)event->height!=window->height || (unsigned)event->border_width!=window->border)
 824         {
 825                 window->width = event->width;
 826                 window->height = event->height;
 827                 window->border = event->border_width;
 828                 create_window_pixmap(compositor, screen, window);
 829         }
 830         reorder_window(screen, window, event->above);
 831
 832         if(window->map_state==IsViewable)
 833                 mark_dirty(compositor, screen);
 834 }
 835
 836 void process_damage_event(Compositor *compositor, XDamageNotifyEvent *event)
 837 {
 838         CompositedScreen *screen;
 839         CompositedWindow *window;
 840
 841         screen = find_screen_by_window(compositor, event->drawable);
 842         if(!screen)
 843                 return;
 844
 845         window = find_window(screen, event->drawable);
 846         if(window->map_state==IsViewable)
 847                 mark_dirty(compositor, screen);
 848 }
 849
 850 int process_event(Compositor *compositor)
 851 {
 852         XEvent event;
 853         if(compositor->dirty)
 854         {
 855                 if(!XCheckMaskEvent(compositor->display, -1, &event))
 856                         return 0;
 857         }
 858         else
 859                 XNextEvent(compositor->display, &event);
 860
 861         switch(event.type)
 862         {
 863         case CreateNotify:
 864                 process_create_window_event(compositor, &event.xcreatewindow);
 865                 break;
 866         case DestroyNotify:
 867                 process_destroy_window_event(compositor, &event.xdestroywindow);
 868                 break;
 869         case MapNotify:
 870                 process_map_event(compositor, &event.xmap);
 871                 break;
 872         case UnmapNotify:
 873                 process_unmap_event(compositor, &event.xunmap);
 874                 break;
 875         case ReparentNotify:
 876                 process_reparent_event(compositor, &event.xreparent);
 877                 break;
 878         case ConfigureNotify:
 879                 process_configure_event(compositor, &event.xconfigure);
 880                 break;
 881         default:
 882                 if(event.type==compositor->damage_event+XDamageNotify)
 883                         process_damage_event(compositor, (XDamageNotifyEvent *)&event);
 884                 else
 885                         printf("Event %d\n", event.type);
 886         }
 887
 888         return 1;
 889 }
 890
 891 void refresh_screen(Compositor *compositor, CompositedScreen *screen)
 892 {
 893         unsigned i;
 894
 895         use_gl(compositor, screen);
 896
 897         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, screen->framebuffer);
 898
 899         glClearColor(0.5f, 0.5f, 0.5f, 0.0f);
 900         glClear(GL_COLOR_BUFFER_BIT);
 901
 902         glUseProgram(screen->program);
 903         glBindVertexArray(screen->window_vertex_array);
 904         for(i=0; i<screen->nwindows; ++i)
 905         {
 906                 CompositedWindow *window = &screen->windows[i];
 907                 if(window->map_state!=IsViewable)
 908                         continue;
 909
 910                 glBindTexture(GL_TEXTURE_2D, window->texture);
 911                 compositor->glXBindTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT, NULL);
 912                 glUniform4f(screen->geometry_loc,
 913                         (float)window->x/screen->width, ((float)screen->height-window->y-window->height)/screen->height,
 914                         (float)(window->width+2*window->border)/screen->width, (float)(window->height+2*window->border)/screen->height);
 915                 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 916                 compositor->glXReleaseTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT);
 917                 XDamageSubtract(compositor->display, window->damage, None, None);
 918         }
 919
 920         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 921         glClearColor(0.5f, 0.0f, 0.5f, 0.0f);
 922         glClear(GL_COLOR_BUFFER_BIT);
 923         glBindTexture(GL_TEXTURE_2D, screen->fb_texture);
 924         glEnable(GL_PRIMITIVE_RESTART);
 925         glPrimitiveRestartIndex(0xFFFF);
 926
 927         for(i=0; i<screen->nmonitors; ++i)
 928         {
 929                 CompositedMonitor *monitor = &screen->monitors[i];
 930                 if(!monitor->enabled)
 931                         continue;
 932
 933                 glUniform4f(screen->geometry_loc,
 934                         (float)monitor->x/screen->width, (float)monitor->y/screen->height,
 935                         (float)monitor->width/screen->width, (float)monitor->height/screen->height);
 936
 937                 glBindVertexArray(monitor->vertex_array);
 938                 glDrawElements(GL_TRIANGLE_STRIP, monitor->nelements, GL_UNSIGNED_SHORT, NULL);
 939         }
 940
 941         glXSwapBuffers(compositor->display, screen->glx_window);
 942
 943         screen->dirty = 0;
 944 }
 945
 946 void refresh_all_screens(Compositor *compositor)
 947 {
 948         unsigned i;
 949
 950         for(i=0; i<compositor->nscreens; ++i)
 951         {
 952                 CompositedScreen *screen = &compositor->screens[i];
 953                 if(screen->dirty)
 954                         refresh_screen(compositor, screen);
 955         }
 956
 957         compositor->dirty = 0;
 958 }
 959
 960 void sighandler(int sig)
 961 {
 962         terminate_requested = 1;
 963         (void)sig;
 964 }
 965
 966 int main()
 967 {
 968         Compositor compositor;
 969
 970         signal(SIGINT, &sighandler);
 971         signal(SIGTERM, &sighandler);
 972
 973         if(!initialize_compositor(&compositor))
 974                 return 1;
 975
 976         while(!terminate_requested)
 977         {
 978                 if(!process_event(&compositor))
 979                         refresh_all_screens(&compositor);
 980         }
 981
 982         shutdown_compositor(&compositor);
 983
 984         return 0;
 985 }