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 <math.h>
   7 #include <X11/Xlib.h>
   8 #include <X11/Xatom.h>
   9 #include <X11/extensions/Xcomposite.h>
  10 #include <X11/extensions/Xdamage.h>
  11 #include <X11/extensions/shape.h>
  12 #include <X11/extensions/Xrandr.h>
  13 #include <GL/gl.h>
  14 #include <GL/glx.h>
  15
  16 typedef struct CompositedWindow
  17 {
  18         Window window;
  19         int x;
  20         int y;
  21         unsigned width;
  22         unsigned height;
  23         unsigned border;
  24         int map_state;
  25         Damage damage;
  26         Pixmap pixmap;
  27         GLXPixmap glx_pixmap;
  28         unsigned texture;
  29 } CompositedWindow;
  30
  31 typedef struct CompositedMonitor
  32 {
  33         char *name;
  34         int enabled;
  35         int x;
  36         int y;
  37         unsigned width;
  38         unsigned height;
  39         float keystone_vertical;
  40         float cylinder_depth;
  41         float vertical_center;
  42         float perspective;
  43         unsigned vertex_buffer;
  44         unsigned index_buffer;
  45         unsigned vertex_array;
  46         unsigned tessellation;
  47         unsigned nelements;
  48 } CompositedMonitor;
  49
  50 typedef struct CompositedScreen
  51 {
  52         int number;
  53         Window root;
  54         unsigned width;
  55         unsigned height;
  56         Window overlay;
  57         Window render_window;
  58         GLXFBConfig fbconfig;
  59         GLXWindow glx_window;
  60         GLXContext glx_context;
  61         unsigned shaders[2];
  62         unsigned program;
  63         unsigned geometry_loc;
  64         unsigned window_vertex_buffer;
  65         unsigned window_vertex_array;
  66         unsigned framebuffer;
  67         unsigned fb_texture;
  68         CompositedWindow *windows;
  69         unsigned nwindows;
  70         unsigned windows_capacity;
  71         CompositedMonitor *monitors;
  72         unsigned nmonitors;
  73         int dirty;
  74 } CompositedScreen;
  75
  76 typedef struct Compositor
  77 {
  78         Display *display;
  79         CompositedScreen *screens;
  80         unsigned nscreens;
  81         int damage_event;
  82         PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribsARB;
  83         PFNGLXBINDTEXIMAGEEXTPROC glXBindTexImageEXT;
  84         PFNGLXRELEASETEXIMAGEEXTPROC glXReleaseTexImageEXT;
  85         Atom correction_atom;
  86         Atom monitors_atom;
  87         int dirty;
  88 } Compositor;
  89
  90 static const char *vshader =
  91         "#version 150\n"
  92         "uniform vec4 geometry;\n"
  93         "in vec2 vertex;\n"
  94         "in vec2 texture_coord;\n"
  95         "out vec2 texcoord;\n"
  96         "void main()\n"
  97         "{\n"
  98         "  gl_Position = vec4((geometry.xy+vertex*geometry.zw)*2.0-1.0, 0.0, 1.0);\n"
  99         "  texcoord = texture_coord;\n"
 100         "}\n";
 101
 102 static const char *fshader =
 103         "#version 150\n"
 104         "uniform sampler2D image;\n"
 105         "in vec2 texcoord;\n"
 106         "out vec4 frag_color;\n"
 107         "void main()\n"
 108         "{\n"
 109         "       frag_color = texture(image, texcoord);\n"
 110         "}\n";
 111
 112 static const float window_vertices[] =
 113 {
 114         /* vertex    texcoord */
 115         0.0f, 1.0f,  0.0f, 0.0f,
 116         0.0f, 0.0f,  0.0f, 1.0f,
 117         1.0f, 1.0f,  1.0f, 0.0f,
 118         1.0f, 0.0f,  1.0f, 1.0f
 119 };
 120
 121 int terminate_requested = 0;
 122
 123 int x_error_handler(Display *display, XErrorEvent *event)
 124 {
 125         printf("Ignoring X error %d on resource %lx\n", event->error_code, event->resourceid);
 126         (void)display;
 127         return 0;
 128 }
 129
 130 int with_error(const char *message)
 131 {
 132         fprintf(stderr, "%s\n", message);
 133         return 0;
 134 }
 135
 136 int initialize_gl(Compositor *compositor, CompositedScreen *screen)
 137 {
 138         int attribs[9];
 139         unsigned i;
 140         GLXFBConfig *configs;
 141         int nconfigs;
 142         XVisualInfo *vi;
 143         XSetWindowAttributes win_attr;
 144
 145         i = 0;
 146         attribs[i++] = GLX_DRAWABLE_TYPE;
 147         attribs[i++] = GLX_WINDOW_BIT;
 148         attribs[i++] = GLX_RENDER_TYPE;
 149         attribs[i++] = GLX_RGBA_BIT;
 150         attribs[i++] = GLX_DOUBLEBUFFER;
 151         attribs[i++] = True;
 152         attribs[i++] = GLX_BIND_TO_TEXTURE_RGBA_EXT;
 153         attribs[i++] = True;
 154         attribs[i] = None;
 155
 156         configs = glXChooseFBConfig(compositor->display, screen->number, attribs, &nconfigs);
 157         if(!configs || !nconfigs)
 158                 return with_error("Could not find a suitable FBConfig");
 159         screen->fbconfig = configs[0];
 160         XFree(configs);
 161
 162         vi = glXGetVisualFromFBConfig(compositor->display, screen->fbconfig);
 163         win_attr.colormap = XCreateColormap(compositor->display, screen->root, vi->visual, AllocNone);
 164         screen->render_window = XCreateWindow(compositor->display, screen->overlay, 0, 0, screen->width, screen->height, 0, vi->depth, InputOutput, vi->visual, CWColormap, &win_attr);
 165         XMapWindow(compositor->display, screen->render_window);
 166
 167         screen->glx_window = glXCreateWindow(compositor->display, screen->fbconfig, screen->render_window, NULL);
 168
 169         i = 0;
 170         attribs[i++] = GLX_CONTEXT_FLAGS_ARB;
 171         attribs[i++] = GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
 172         attribs[i++] = GLX_CONTEXT_MAJOR_VERSION_ARB;
 173         attribs[i++] = 3;
 174         attribs[i++] = GLX_CONTEXT_MINOR_VERSION_ARB;
 175         attribs[i++] = 1;
 176         attribs[i] = None;
 177
 178         screen->glx_context = compositor->glXCreateContextAttribsARB(compositor->display, screen->fbconfig, NULL, True, attribs);
 179
 180         XFree(vi);
 181
 182         return 1;
 183 }
 184
 185 void use_gl(Compositor *compositor, CompositedScreen *screen)
 186 {
 187         glXMakeContextCurrent(compositor->display, screen->glx_window, screen->glx_window, screen->glx_context);
 188 }
 189
 190 unsigned compile_shader(GLenum type, const char *source)
 191 {
 192         unsigned shader;
 193         int status;
 194         char info_log[1024];
 195         GLsizei length;
 196
 197         shader = glCreateShader(type);
 198         glShaderSource(shader, 1, &source, NULL);
 199         glCompileShader(shader);
 200         glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
 201         glGetShaderInfoLog(shader, sizeof(info_log), &length, info_log);
 202         if(!status)
 203         {
 204                 fprintf(stderr, "Shader compilation failed:\n%s\n", info_log);
 205                 glDeleteShader(shader);
 206                 return 0;
 207         }
 208         else if(length)
 209                 printf("Shader info log:\n%s\n", info_log);
 210
 211         return shader;
 212 }
 213
 214 unsigned link_program(unsigned *shaders, unsigned nshaders)
 215 {
 216         unsigned program;
 217         unsigned i;
 218         int status;
 219         char info_log[1024];
 220         GLsizei length;
 221
 222         program = glCreateProgram();
 223         for(i=0; i<nshaders; ++i)
 224                 glAttachShader(program, shaders[i]);
 225         glBindAttribLocation(program, 0, "vertex");
 226         glBindAttribLocation(program, 1, "texture_coord");
 227         glBindFragDataLocation(program, 0, "frag_color");
 228         glLinkProgram(program);
 229
 230         glGetProgramiv(program, GL_LINK_STATUS, &status);
 231         glGetProgramInfoLog(program, sizeof(info_log), &length, info_log);
 232         if(!status)
 233         {
 234                 fprintf(stderr, "Program link failed:\n%s\n", info_log);
 235                 glDeleteProgram(program);
 236                 return 0;
 237         }
 238         else if(length)
 239                 printf("Program info log:\n%s\n", info_log);
 240
 241         return program;
 242 }
 243
 244 int create_gl_resources(Compositor *compositor, CompositedScreen *screen)
 245 {
 246         unsigned stride;
 247
 248         use_gl(compositor, screen);
 249
 250         screen->shaders[0] = compile_shader(GL_VERTEX_SHADER, vshader);
 251         screen->shaders[1] = compile_shader(GL_FRAGMENT_SHADER, fshader);
 252         if(!screen->shaders[0] || !screen->shaders[1])
 253                 return 0;
 254
 255         screen->program = link_program(screen->shaders, 2);
 256         if(!screen->program)
 257                 return 0;
 258
 259         screen->geometry_loc = glGetUniformLocation(screen->program, "geometry");
 260
 261         glGenBuffers(1, &screen->window_vertex_buffer);
 262         glBindBuffer(GL_ARRAY_BUFFER, screen->window_vertex_buffer);
 263         glBufferData(GL_ARRAY_BUFFER, sizeof(window_vertices), window_vertices, GL_STATIC_DRAW);
 264
 265         stride = 4*sizeof(float);
 266         glGenVertexArrays(1, &screen->window_vertex_array);
 267         glBindVertexArray(screen->window_vertex_array);
 268         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, stride, NULL);
 269         glEnableVertexAttribArray(0);
 270         glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, (void *)(2*sizeof(float)));
 271         glEnableVertexAttribArray(1);
 272         glBindVertexArray(0);
 273
 274         glBindBuffer(GL_ARRAY_BUFFER, 0);
 275
 276         glGenTextures(1, &screen->fb_texture);
 277         glBindTexture(GL_TEXTURE_2D, screen->fb_texture);
 278         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, screen->width, screen->height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
 279         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 280         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 281         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 282         glBindTexture(GL_TEXTURE_2D, 0);
 283
 284         glGenFramebuffers(1, &screen->framebuffer);
 285         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, screen->framebuffer);
 286         glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, screen->fb_texture, 0);
 287         glDepthMask(GL_FALSE);
 288         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 289
 290         return 1;
 291 }
 292
 293 CompositedWindow *find_window(CompositedScreen *screen, Window w)
 294 {
 295         unsigned i;
 296
 297         for(i=0; i<screen->nwindows; ++i)
 298                 if(screen->windows[i].window==w)
 299                         return &screen->windows[i];
 300
 301         return NULL;
 302 }
 303
 304 void create_window_pixmap(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window)
 305 {
 306         int attribs[5];
 307         unsigned i;
 308
 309         if(window->pixmap)
 310         {
 311                 glXDestroyPixmap(compositor->display, window->glx_pixmap);
 312                 XFreePixmap(compositor->display, window->pixmap);
 313         }
 314
 315         i = 0;
 316         attribs[i++] = GLX_TEXTURE_TARGET_EXT;
 317         attribs[i++] = GLX_TEXTURE_2D_EXT;
 318         attribs[i++] = GLX_TEXTURE_FORMAT_EXT;
 319         attribs[i++] = GLX_TEXTURE_FORMAT_RGBA_EXT;
 320         attribs[i++] = None;
 321
 322         window->pixmap = XCompositeNameWindowPixmap(compositor->display, window->window);
 323         window->glx_pixmap = glXCreatePixmap(compositor->display, screen->fbconfig, window->pixmap, attribs);
 324 }
 325
 326 CompositedWindow *add_window(Compositor *compositor, CompositedScreen *screen, Window w)
 327 {
 328         CompositedWindow *window;
 329         XWindowAttributes win_attr;
 330
 331         if(w==screen->root || w==screen->overlay)
 332                 return NULL;
 333
 334         if(!XGetWindowAttributes(compositor->display, w, &win_attr))
 335         {
 336                 printf("XGetWindowAttributes failed; probably the window was already destroyed\n");
 337                 return NULL;
 338         }
 339         if(win_attr.class==InputOnly)
 340                 return NULL;
 341
 342         if(find_window(screen, w))
 343                 return NULL;
 344
 345         if(screen->nwindows==screen->windows_capacity)
 346         {
 347                 screen->windows = (CompositedWindow *)realloc(screen->windows, (screen->windows_capacity+1)*sizeof(CompositedWindow));
 348                 ++screen->windows_capacity;
 349         }
 350
 351         window = &screen->windows[screen->nwindows++];
 352
 353         window->window = w;
 354         window->x = win_attr.x;
 355         window->y = win_attr.y;
 356         window->width = win_attr.width;
 357         window->height = win_attr.height;
 358         window->border = win_attr.border_width;
 359         window->map_state = win_attr.map_state;
 360
 361         window->damage = XDamageCreate(compositor->display, window->window, XDamageReportNonEmpty);
 362         window->pixmap = None;
 363         window->glx_pixmap = None;
 364
 365         XCompositeRedirectWindow(compositor->display, window->window, CompositeRedirectManual);
 366         if(window->map_state==IsViewable)
 367                 create_window_pixmap(compositor, screen, window);
 368
 369         glGenTextures(1, &window->texture);
 370         glBindTexture(GL_TEXTURE_2D, window->texture);
 371         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 372         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 373         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 374
 375         return window;
 376 }
 377
 378 void remove_window(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window, int destroyed)
 379 {
 380         unsigned i;
 381
 382         glDeleteTextures(1, &window->texture);
 383         if(!destroyed)
 384         {
 385                 XDamageDestroy(compositor->display, window->damage);
 386                 if(window->pixmap)
 387                 {
 388                         glXDestroyPixmap(compositor->display, window->glx_pixmap);
 389                         XFreePixmap(compositor->display, window->pixmap);
 390                 }
 391                 XCompositeUnredirectWindow(compositor->display, window->window, CompositeRedirectManual);
 392         }
 393
 394         --screen->nwindows;
 395         for(i=window-screen->windows; i<screen->nwindows; ++i)
 396                 screen->windows[i] = screen->windows[i+1];
 397 }
 398
 399 CompositedWindow *reorder_window(CompositedScreen *screen, CompositedWindow *window, Window above)
 400 {
 401         unsigned i, j;
 402         CompositedWindow hold;
 403
 404         i = window-screen->windows;
 405         if(above)
 406         {
 407                 for(j=0; j<screen->nwindows; ++j)
 408                         if(screen->windows[j].window==above)
 409                                 break;
 410
 411                 if(j>=screen->nwindows || i==j+1)
 412                         return window;
 413
 414                 if(j<i)
 415                         ++j;
 416         }
 417         else
 418                 j = 0;
 419
 420         hold = *window;
 421         if(i<j)
 422         {
 423                 for(; i<j; ++i)
 424                         screen->windows[i] = screen->windows[i+1];
 425         }
 426         else
 427         {
 428                 for(; i>j; --i)
 429                         screen->windows[i] = screen->windows[i-1];
 430         }
 431         screen->windows[j] = hold;
 432
 433         return &screen->windows[j];
 434 }
 435
 436 CompositedScreen *find_screen_by_root(Compositor *compositor, Window root)
 437 {
 438         unsigned i;
 439
 440         for(i=0; i<compositor->nscreens; ++i)
 441                 if(compositor->screens[i].root==root)
 442                         return &compositor->screens[i];
 443
 444         return NULL;
 445 }
 446
 447 CompositedScreen *find_screen_by_window(Compositor *compositor, Window w)
 448 {
 449         unsigned i, j;
 450
 451         for(i=0; i<compositor->nscreens; ++i)
 452                 for(j=0; j<compositor->screens[i].nwindows; ++j)
 453                         if(compositor->screens[i].windows[j].window==w)
 454                                 return &compositor->screens[i];
 455
 456         return NULL;
 457 }
 458
 459 void update_monitor_vertices(CompositedScreen *screen, CompositedMonitor *monitor)
 460 {
 461         unsigned t;
 462         unsigned data_size;
 463         float *vertex_data;
 464         unsigned short *index_data;
 465         unsigned x, y;
 466         unsigned i;
 467         float aspect;
 468         float cyl_w_sq;
 469         float sin_ksv;
 470         float cos_ksv;
 471
 472         t = monitor->tessellation;
 473
 474         data_size = (t+1)*(t+1)*4*sizeof(float);
 475         vertex_data = (float *)malloc(data_size);
 476         aspect = (float)monitor->width/monitor->height;
 477         cyl_w_sq = 0.25f-(0.5f-monitor->cylinder_depth)*(0.5f-monitor->cylinder_depth);
 478         sin_ksv = monitor->keystone_vertical/sqrt(1.0f+monitor->keystone_vertical*monitor->keystone_vertical);
 479         cos_ksv = sqrt(1.0f-sin_ksv*sin_ksv);
 480         for(y=0; y<=t; ++y)
 481                 for(x=0; x<=t; ++x)
 482                 {
 483                         float xf, yf, z, rz;
 484                         float scale;
 485                         float *v;
 486
 487                         xf = (float)x/t;
 488                         yf = (float)y/t;
 489
 490                         v = vertex_data+(y*(t+1)+x)*4;
 491                         v[2] = (monitor->x+xf*monitor->width)/screen->width;
 492                         v[3] = ((float)screen->height-monitor->y-monitor->height+yf*monitor->height)/screen->height;
 493
 494                         z = sqrt(0.25f-(xf-0.5f)*(xf-0.5f)*4.0f*cyl_w_sq)-0.5f+monitor->cylinder_depth;
 495                         if(monitor->keystone_vertical>0)
 496                         {
 497                                 rz = (1.0f-yf)/aspect*sin_ksv+z*cos_ksv;
 498                                 yf = 1.0f-((1.0f-yf)*cos_ksv-z*aspect*sin_ksv);
 499                                 z = rz;
 500                         }
 501                         else if(monitor->keystone_vertical<0)
 502                         {
 503                                 rz = z*cos_ksv-yf/aspect*sin_ksv;
 504                                 yf = yf*cos_ksv+z*aspect*sin_ksv;
 505                                 z = rz;
 506                         }
 507                         scale = monitor->perspective/(monitor->perspective+z);
 508                         v[0] = 0.5f+(xf-0.5f)*scale;
 509                         v[1] = monitor->vertical_center+(yf-monitor->vertical_center)*scale;
 510                 }
 511         glBindBuffer(GL_ARRAY_BUFFER, monitor->vertex_buffer);
 512         glBufferData(GL_ARRAY_BUFFER, data_size, vertex_data, GL_STATIC_DRAW);
 513         glBindBuffer(GL_ARRAY_BUFFER, 0);
 514         free(vertex_data);
 515
 516         monitor->nelements = t*((t+1)*2+1)-1;
 517         data_size = monitor->nelements*sizeof(unsigned short);
 518         index_data = (unsigned short *)malloc(data_size);
 519         i = 0;
 520         for(y=0; y<t; ++y)
 521         {
 522                 if(y>0)
 523                         index_data[i++] = 0xFFFF;
 524                 for(x=0; x<=t; ++x)
 525                 {
 526                         index_data[i++] = (y+1)*(t+1)+x;
 527                         index_data[i++] = y*(t+1)+x;
 528                 }
 529         }
 530         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, monitor->index_buffer);
 531         glBufferData(GL_ELEMENT_ARRAY_BUFFER, data_size, index_data, GL_STATIC_DRAW);
 532         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 533         free(index_data);
 534 }
 535
 536 int initialize_monitor(Compositor *compositor, CompositedScreen *screen, XRRScreenResources *xrr_res, unsigned index)
 537 {
 538         CompositedMonitor *monitor;
 539         XRROutputInfo *output;
 540         int namelen;
 541         XRRCrtcInfo *crtc;
 542         unsigned buffers[2];
 543         unsigned stride;
 544
 545         monitor = &screen->monitors[index];
 546
 547         output = XRRGetOutputInfo(compositor->display, xrr_res, xrr_res->outputs[index]);
 548         namelen = strlen(output->name);
 549         monitor->name = (char *)malloc(namelen+1);
 550         strcpy(monitor->name, output->name);
 551         monitor->enabled = !!output->crtc;
 552         if(!monitor->enabled)
 553         {
 554                 XRRFreeOutputInfo(output);
 555                 return 1;
 556         }
 557
 558         crtc = XRRGetCrtcInfo(compositor->display, xrr_res, output->crtc);
 559         monitor->x = crtc->x;
 560         monitor->y = crtc->y;
 561         monitor->width = crtc->width;
 562         monitor->height = crtc->height;
 563         XRRFreeCrtcInfo(crtc);
 564         XRRFreeOutputInfo(output);
 565
 566         monitor->keystone_vertical = 0.0f;
 567         monitor->cylinder_depth = 0.0f;
 568         monitor->vertical_center = 0.5f;
 569         monitor->perspective = 1.0f;
 570
 571         glGenBuffers(2, buffers);
 572         monitor->vertex_buffer = buffers[0];
 573         monitor->index_buffer = buffers[1];
 574
 575         monitor->tessellation = 50;
 576         update_monitor_vertices(screen, monitor);
 577         stride = 4*sizeof(float);
 578
 579         glGenVertexArrays(1, &monitor->vertex_array);
 580         glBindVertexArray(monitor->vertex_array);
 581         glBindBuffer(GL_ARRAY_BUFFER, monitor->vertex_buffer);
 582         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, stride, NULL);
 583         glEnableVertexAttribArray(0);
 584         glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, (void *)(2*sizeof(float)));
 585         glEnableVertexAttribArray(1);
 586         glBindBuffer(GL_ARRAY_BUFFER, 0);
 587         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, monitor->index_buffer);
 588         glBindVertexArray(0);
 589
 590         return 1;
 591 }
 592
 593 CompositedMonitor *find_monitor_by_name(CompositedScreen *screen, char *name)
 594 {
 595         unsigned i;
 596
 597         for(i=0; i<screen->nmonitors; ++i)
 598                 if(!strcmp(screen->monitors[i].name, name))
 599                         return &screen->monitors[i];
 600
 601         return NULL;
 602 }
 603
 604 void update_geometry_correction(Compositor *compositor, CompositedScreen *screen)
 605 {
 606         Atom prop_type;
 607         int prop_format;
 608         unsigned long overflow;
 609         unsigned long names_length;
 610         char *names;
 611         unsigned long values_length;
 612         short *values;
 613         char *name_ptr;
 614         unsigned i;
 615
 616         XGetWindowProperty(compositor->display, screen->root, compositor->monitors_atom, 0, 64, False, XA_STRING,
 617                 &prop_type, &prop_format, &names_length, &overflow, (unsigned char **)&names);
 618         if(prop_type!=XA_STRING || prop_format!=8)
 619                 return;
 620
 621         XGetWindowProperty(compositor->display, screen->root, compositor->correction_atom, 0, 64, False, XA_INTEGER,
 622                 &prop_type, &prop_format, &values_length, &overflow, (unsigned char **)&values);
 623         if(prop_type!=XA_INTEGER || prop_format!=16)
 624         {
 625                 XFree(names);
 626                 return;
 627         }
 628
 629         use_gl(compositor, screen);
 630
 631         name_ptr = names;
 632         for(i=0; i*4<values_length; ++i)
 633         {
 634                 CompositedMonitor *monitor;
 635
 636                 if(name_ptr>=names+names_length)
 637                         break;
 638
 639                 monitor = find_monitor_by_name(screen, name_ptr);
 640                 if(monitor)
 641                 {
 642                         monitor->keystone_vertical = values[i*4]/10000.0f;
 643                         monitor->cylinder_depth = values[i*4+1]/10000.0f;
 644                         monitor->vertical_center = values[i*4+2]/10000.0f;
 645                         monitor->perspective = values[i*4+3]/10000.0f;
 646
 647                         if(monitor->enabled)
 648                                 update_monitor_vertices(screen, monitor);
 649                 }
 650
 651                 name_ptr += strlen(name_ptr)+1;
 652         }
 653
 654         XFree(names);
 655         XFree(values);
 656 }
 657
 658 int initialize_screen(Compositor *compositor, unsigned number)
 659 {
 660         CompositedScreen *screen;
 661         const char *extensions;
 662         Window dummy_root;
 663         int x, y;
 664         unsigned border;
 665         unsigned depth;
 666         XRRScreenResources *xrr_res;
 667         Window dummy_parent;
 668         Window *children;
 669         unsigned nchildren;
 670         unsigned i;
 671
 672         screen = &compositor->screens[number];
 673         screen->number = number;
 674
 675         extensions = glXQueryExtensionsString(compositor->display, screen->number);
 676         if(!strstr(extensions, "GLX_ARB_create_context"))
 677                 return with_error("GLX_ARB_create_context is required");
 678         if(!strstr(extensions, "GLX_EXT_texture_from_pixmap"))
 679                 return with_error("GLX_EXT_texture_from_pixmap is required");
 680
 681         screen->root = RootWindow(compositor->display, screen->number);
 682         XSelectInput(compositor->display, screen->root, SubstructureNotifyMask|PropertyChangeMask);
 683         screen->overlay = XCompositeGetOverlayWindow(compositor->display, screen->root);
 684         XGetGeometry(compositor->display, screen->overlay, &dummy_root, &x, &y, &screen->width, &screen->height, &border, &depth);
 685         XShapeCombineRectangles(compositor->display, screen->overlay, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted);
 686
 687         if(!initialize_gl(compositor, screen))
 688                 return 0;
 689
 690         if(!create_gl_resources(compositor, screen))
 691                 return 0;
 692
 693         xrr_res = XRRGetScreenResources(compositor->display, screen->root);
 694         screen->nmonitors = xrr_res->noutput;
 695         screen->monitors = (CompositedMonitor *)malloc(screen->nmonitors*sizeof(CompositedMonitor));
 696         for(i=0; i<screen->nmonitors; ++i)
 697                 if(!initialize_monitor(compositor, screen, xrr_res, i))
 698                         return 0;
 699         XRRFreeScreenResources(xrr_res);
 700
 701         update_geometry_correction(compositor, screen);
 702
 703         XQueryTree(compositor->display, screen->root, &dummy_root, &dummy_parent, &children, &nchildren);
 704
 705         screen->windows = (CompositedWindow *)malloc(nchildren*sizeof(CompositedWindow));
 706         screen->nwindows = 0;
 707         screen->windows_capacity = nchildren;
 708
 709         for(i=0; i<nchildren; ++i)
 710                 add_window(compositor, screen, children[i]);
 711
 712         XFree(children);
 713
 714         screen->dirty = 1;
 715
 716         return 1;
 717 }
 718
 719 int initialize_compositor(Compositor *compositor)
 720 {
 721         int event_base;
 722         int error_base;
 723         int major_ver;
 724         int minor_ver;
 725         unsigned i;
 726
 727         compositor->display = XOpenDisplay(NULL);
 728         if(!compositor->display)
 729                 return with_error("Could not open X display");
 730
 731         XSetErrorHandler(&x_error_handler);
 732
 733         if(!XCompositeQueryExtension(compositor->display, &event_base, &error_base))
 734                 return with_error("XComposite is required but was not found");
 735         else if(!XCompositeQueryVersion(compositor->display, &major_ver, &minor_ver))
 736                 return with_error("Cannot determine XComposite version");
 737         else if(major_ver==0 && minor_ver<3)
 738                 return with_error("XComposite 0.3 or later is required");
 739
 740         if(!glXQueryExtension(compositor->display, &event_base, &error_base))
 741                 return with_error("GLX is required but was not found");
 742         else if(!glXQueryVersion(compositor->display, &major_ver, &minor_ver))
 743                 return with_error("Cannot determine GLX version");
 744         else if(major_ver<1 || (major_ver==1 && minor_ver<4))
 745                 return with_error("GLX 1.4 or later is required");
 746
 747         if(!XDamageQueryExtension(compositor->display, &compositor->damage_event, &error_base))
 748                 return with_error("XDamage is required but was not found");
 749         else if(!XDamageQueryVersion(compositor->display, &major_ver, &minor_ver))
 750                 return with_error("Cannot determine XDamage version");
 751         else if(major_ver<1)
 752                 return with_error("XDamage 1.0 or later is required");
 753
 754         if(!XShapeQueryExtension(compositor->display, &event_base, &error_base))
 755                 return with_error("XShape is required but was not found");
 756         else if(!XShapeQueryVersion(compositor->display, &major_ver, &minor_ver))
 757                 return with_error("Cannot determine XShape version");
 758         else if(major_ver<1 || (major_ver==1 && minor_ver<1))
 759                 return with_error("XShape 1.1 or later is required");
 760
 761         if(!XRRQueryExtension(compositor->display, &event_base, &error_base))
 762                 return with_error("XRandR is required but was not found");
 763         else if(!XRRQueryVersion(compositor->display, &major_ver, &minor_ver))
 764                 return with_error("Cannot determine XRandR version");
 765         else if(major_ver<1 || (major_ver==1 && minor_ver<2))
 766                 return with_error("XRandR 1.2 or later is required");
 767
 768         compositor->glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((unsigned char *)"glXCreateContextAttribsARB");
 769         compositor->glXBindTexImageEXT = (PFNGLXBINDTEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXBindTexImageEXT");
 770         compositor->glXReleaseTexImageEXT = (PFNGLXRELEASETEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXReleaseTexImageEXT");
 771
 772         compositor->correction_atom = XInternAtom(compositor->display, "GEOMETRY_CORRECTION", False);
 773         compositor->monitors_atom = XInternAtom(compositor->display, "GEOMETRY_CORRECTION_MONITORS", False);
 774
 775         compositor->nscreens = ScreenCount(compositor->display);
 776         compositor->screens = (CompositedScreen *)malloc(compositor->nscreens*sizeof(CompositedScreen));
 777         for(i=0; i<compositor->nscreens; ++i)
 778                 if(!initialize_screen(compositor, i))
 779                         return 0;
 780
 781         compositor->dirty = 1;
 782
 783         return 1;
 784 }
 785
 786 void shutdown_screen(Compositor *compositor, CompositedScreen *screen)
 787 {
 788         unsigned i;
 789
 790         use_gl(compositor, screen);
 791
 792         for(i=0; i<screen->nwindows; ++i)
 793         {
 794                 glDeleteTextures(1, &screen->windows[i].texture);
 795                 if(screen->windows[i].pixmap)
 796                 {
 797                         glXDestroyPixmap(compositor->display, screen->windows[i].glx_pixmap);
 798                         XFreePixmap(compositor->display, screen->windows[i].pixmap);
 799                         XDamageDestroy(compositor->display, screen->windows[i].damage);
 800                 }
 801         }
 802
 803         for(i=0; i<screen->nmonitors; ++i)
 804         {
 805                 free(screen->monitors[i].name);
 806                 if(screen->monitors[i].enabled)
 807                 {
 808                         glDeleteBuffers(1, &screen->monitors[i].vertex_buffer);
 809                         glDeleteBuffers(1, &screen->monitors[i].index_buffer);
 810                         glDeleteVertexArrays(1, &screen->monitors[i].vertex_array);
 811                 }
 812         }
 813
 814         glDeleteBuffers(1, &screen->window_vertex_buffer);
 815         glDeleteVertexArrays(1, &screen->window_vertex_array);
 816         glDeleteFramebuffers(1, &screen->framebuffer);
 817         glDeleteTextures(1, &screen->fb_texture);
 818         glDeleteProgram(screen->program);
 819         glDeleteShader(screen->shaders[0]);
 820         glDeleteShader(screen->shaders[1]);
 821
 822         glXMakeContextCurrent(compositor->display, 0, 0, NULL);
 823         glXDestroyContext(compositor->display, screen->glx_context);
 824         glXDestroyWindow(compositor->display, screen->glx_window);
 825         XDestroyWindow(compositor->display, screen->render_window);
 826
 827         XCompositeReleaseOverlayWindow(compositor->display, screen->overlay);
 828
 829         free(screen->windows);
 830         free(screen->monitors);
 831 }
 832
 833 void shutdown_compositor(Compositor *compositor)
 834 {
 835         unsigned i;
 836
 837         for(i=0; i<compositor->nscreens; ++i)
 838                 shutdown_screen(compositor, &compositor->screens[i]);
 839         free(compositor->screens);
 840
 841         XCloseDisplay(compositor->display);
 842 }
 843
 844 void mark_dirty(Compositor *compositor, CompositedScreen *screen)
 845 {
 846         compositor->dirty = 1;
 847         screen->dirty = 1;
 848 }
 849
 850 void process_create_window_event(Compositor *compositor, XCreateWindowEvent *event)
 851 {
 852         CompositedScreen *screen;
 853
 854         if((screen = find_screen_by_root(compositor, event->parent)))
 855                 add_window(compositor, screen, event->window);
 856 }
 857
 858 void process_destroy_window_event(Compositor *compositor, XDestroyWindowEvent *event)
 859 {
 860         CompositedScreen *screen;
 861         CompositedWindow *window;
 862
 863         if((screen = find_screen_by_root(compositor, event->event)))
 864                 if((window = find_window(screen, event->window)))
 865                         remove_window(compositor, screen, window, 1);
 866 }
 867
 868 void process_map_event(Compositor *compositor, XMapEvent *event)
 869 {
 870         CompositedScreen *screen;
 871         CompositedWindow *window;
 872
 873         screen = find_screen_by_root(compositor, event->event);
 874         if(!screen)
 875                 return;
 876
 877         window = find_window(screen, event->window);
 878         if(!window)
 879                 return;
 880
 881         window->map_state = IsViewable;
 882         create_window_pixmap(compositor, screen, window);
 883
 884         mark_dirty(compositor, screen);
 885 }
 886
 887 void process_unmap_event(Compositor *compositor, XUnmapEvent *event)
 888 {
 889         CompositedScreen *screen;
 890         CompositedWindow *window;
 891
 892         screen = find_screen_by_root(compositor, event->event);
 893         if(!screen)
 894                 return;
 895
 896         window = find_window(screen, event->window);
 897         if(window)
 898                 window->map_state = IsUnviewable;
 899
 900         mark_dirty(compositor, screen);
 901 }
 902
 903 void process_reparent_event(Compositor *compositor, XReparentEvent *event)
 904 {
 905         CompositedScreen *screen;
 906         CompositedWindow *window;
 907
 908         screen = find_screen_by_root(compositor, event->event);
 909         if(!screen)
 910                 return;
 911
 912         if(event->parent==screen->root)
 913                 window = add_window(compositor, screen, event->window);
 914         else
 915         {
 916                 window = find_window(screen, event->window);
 917                 if(!window)
 918                         return;
 919
 920                 remove_window(compositor, screen, window, 0);
 921         }
 922
 923         if(window && window->map_state==IsViewable)
 924                 mark_dirty(compositor, screen);
 925 }
 926
 927 void process_configure_event(Compositor *compositor, XConfigureEvent *event)
 928 {
 929         CompositedScreen *screen;
 930         CompositedWindow *window;
 931
 932         screen = find_screen_by_root(compositor, event->event);
 933         if(!screen)
 934                 return;
 935
 936         window = find_window(screen, event->window);
 937         if(!window)
 938                 return;
 939
 940         window->x = event->x;
 941         window->y = event->y;
 942         if((unsigned)event->width!=window->width || (unsigned)event->height!=window->height || (unsigned)event->border_width!=window->border)
 943         {
 944                 window->width = event->width;
 945                 window->height = event->height;
 946                 window->border = event->border_width;
 947                 create_window_pixmap(compositor, screen, window);
 948         }
 949         reorder_window(screen, window, event->above);
 950
 951         if(window->map_state==IsViewable)
 952                 mark_dirty(compositor, screen);
 953 }
 954
 955 void process_property_event(Compositor *compositor, XPropertyEvent *event)
 956 {
 957         CompositedScreen *screen;
 958
 959         if(event->atom!=compositor->correction_atom)
 960                 return;
 961
 962         screen = find_screen_by_root(compositor, event->window);
 963         if(!screen)
 964                 return;
 965
 966         update_geometry_correction(compositor, screen);
 967 }
 968
 969 void process_damage_event(Compositor *compositor, XDamageNotifyEvent *event)
 970 {
 971         CompositedScreen *screen;
 972         CompositedWindow *window;
 973
 974         screen = find_screen_by_window(compositor, event->drawable);
 975         if(!screen)
 976                 return;
 977
 978         window = find_window(screen, event->drawable);
 979         if(window->map_state==IsViewable)
 980                 mark_dirty(compositor, screen);
 981 }
 982
 983 int process_event(Compositor *compositor)
 984 {
 985         XEvent event;
 986         if(compositor->dirty)
 987         {
 988                 if(!XCheckMaskEvent(compositor->display, -1, &event))
 989                         return 0;
 990         }
 991         else
 992                 XNextEvent(compositor->display, &event);
 993
 994         switch(event.type)
 995         {
 996         case CreateNotify:
 997                 process_create_window_event(compositor, &event.xcreatewindow);
 998                 break;
 999         case DestroyNotify:
1000                 process_destroy_window_event(compositor, &event.xdestroywindow);
1001                 break;
1002         case MapNotify:
1003                 process_map_event(compositor, &event.xmap);
1004                 break;
1005         case UnmapNotify:
1006                 process_unmap_event(compositor, &event.xunmap);
1007                 break;
1008         case ReparentNotify:
1009                 process_reparent_event(compositor, &event.xreparent);
1010                 break;
1011         case ConfigureNotify:
1012                 process_configure_event(compositor, &event.xconfigure);
1013                 break;
1014         case PropertyNotify:
1015                 process_property_event(compositor, &event.xproperty);
1016                 break;
1017         default:
1018                 if(event.type==compositor->damage_event+XDamageNotify)
1019                         process_damage_event(compositor, (XDamageNotifyEvent *)&event);
1020                 else
1021                         printf("Event %d\n", event.type);
1022         }
1023
1024         return 1;
1025 }
1026
1027 void refresh_screen(Compositor *compositor, CompositedScreen *screen)
1028 {
1029         unsigned i;
1030
1031         use_gl(compositor, screen);
1032
1033         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, screen->framebuffer);
1034
1035         glClearColor(0.5f, 0.5f, 0.5f, 0.0f);
1036         glClear(GL_COLOR_BUFFER_BIT);
1037
1038         glUseProgram(screen->program);
1039         glBindVertexArray(screen->window_vertex_array);
1040         for(i=0; i<screen->nwindows; ++i)
1041         {
1042                 CompositedWindow *window = &screen->windows[i];
1043                 if(window->map_state!=IsViewable)
1044                         continue;
1045
1046                 glBindTexture(GL_TEXTURE_2D, window->texture);
1047                 compositor->glXBindTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT, NULL);
1048                 glUniform4f(screen->geometry_loc,
1049                         (float)window->x/screen->width, ((float)screen->height-window->y-window->height)/screen->height,
1050                         (float)(window->width+2*window->border)/screen->width, (float)(window->height+2*window->border)/screen->height);
1051                 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
1052                 compositor->glXReleaseTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT);
1053                 XDamageSubtract(compositor->display, window->damage, None, None);
1054         }
1055
1056         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
1057         glClearColor(0.5f, 0.0f, 0.5f, 0.0f);
1058         glClear(GL_COLOR_BUFFER_BIT);
1059         glBindTexture(GL_TEXTURE_2D, screen->fb_texture);
1060         glEnable(GL_PRIMITIVE_RESTART);
1061         glPrimitiveRestartIndex(0xFFFF);
1062
1063         for(i=0; i<screen->nmonitors; ++i)
1064         {
1065                 CompositedMonitor *monitor = &screen->monitors[i];
1066                 if(!monitor->enabled)
1067                         continue;
1068
1069                 glUniform4f(screen->geometry_loc,
1070                         (float)monitor->x/screen->width, ((float)screen->height-monitor->y-monitor->height)/screen->height,
1071                         (float)monitor->width/screen->width, (float)monitor->height/screen->height);
1072
1073                 glBindVertexArray(monitor->vertex_array);
1074                 glDrawElements(GL_TRIANGLE_STRIP, monitor->nelements, GL_UNSIGNED_SHORT, NULL);
1075         }
1076
1077         glBindVertexArray(0);
1078
1079         glXSwapBuffers(compositor->display, screen->glx_window);
1080
1081         screen->dirty = 0;
1082 }
1083
1084 void refresh_all_screens(Compositor *compositor)
1085 {
1086         unsigned i;
1087
1088         for(i=0; i<compositor->nscreens; ++i)
1089         {
1090                 CompositedScreen *screen = &compositor->screens[i];
1091                 if(screen->dirty)
1092                         refresh_screen(compositor, screen);
1093         }
1094
1095         compositor->dirty = 0;
1096 }
1097
1098 void sighandler(int sig)
1099 {
1100         terminate_requested = 1;
1101         (void)sig;
1102 }
1103
1104 int main()
1105 {
1106         Compositor compositor;
1107
1108         signal(SIGINT, &sighandler);
1109         signal(SIGTERM, &sighandler);
1110
1111         if(!initialize_compositor(&compositor))
1112                 return 1;
1113
1114         while(!terminate_requested)
1115         {
1116                 if(!process_event(&compositor))
1117                         refresh_all_screens(&compositor);
1118         }
1119
1120         shutdown_compositor(&compositor);
1121
1122         return 0;
1123 }