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 unsigned create_2d_texture()
 245 {
 246         unsigned texture;
 247         glGenTextures(1, &texture);
 248         glBindTexture(GL_TEXTURE_2D, texture);
 249         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 250         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 251         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 252         return texture;
 253 }
 254
 255 int create_gl_resources(Compositor *compositor, CompositedScreen *screen)
 256 {
 257         unsigned stride;
 258
 259         use_gl(compositor, screen);
 260
 261         screen->shaders[0] = compile_shader(GL_VERTEX_SHADER, vshader);
 262         screen->shaders[1] = compile_shader(GL_FRAGMENT_SHADER, fshader);
 263         if(!screen->shaders[0] || !screen->shaders[1])
 264                 return 0;
 265
 266         screen->program = link_program(screen->shaders, 2);
 267         if(!screen->program)
 268                 return 0;
 269
 270         screen->geometry_loc = glGetUniformLocation(screen->program, "geometry");
 271
 272         glGenBuffers(1, &screen->window_vertex_buffer);
 273         glBindBuffer(GL_ARRAY_BUFFER, screen->window_vertex_buffer);
 274         glBufferData(GL_ARRAY_BUFFER, sizeof(window_vertices), window_vertices, GL_STATIC_DRAW);
 275
 276         stride = 4*sizeof(float);
 277         glGenVertexArrays(1, &screen->window_vertex_array);
 278         glBindVertexArray(screen->window_vertex_array);
 279         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, stride, NULL);
 280         glEnableVertexAttribArray(0);
 281         glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, (void *)(2*sizeof(float)));
 282         glEnableVertexAttribArray(1);
 283         glBindVertexArray(0);
 284
 285         glBindBuffer(GL_ARRAY_BUFFER, 0);
 286
 287         screen->fb_texture = create_2d_texture();
 288         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, screen->width, screen->height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
 289         glBindTexture(GL_TEXTURE_2D, 0);
 290
 291         glGenFramebuffers(1, &screen->framebuffer);
 292         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, screen->framebuffer);
 293         glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, screen->fb_texture, 0);
 294         glDepthMask(GL_FALSE);
 295         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 296
 297         return 1;
 298 }
 299
 300 CompositedWindow *find_window(CompositedScreen *screen, Window w)
 301 {
 302         unsigned i;
 303
 304         for(i=0; i<screen->nwindows; ++i)
 305                 if(screen->windows[i].window==w)
 306                         return &screen->windows[i];
 307
 308         return NULL;
 309 }
 310
 311 CompositedWindow *find_window_global(Compositor *compositor, Window w, CompositedScreen **screen)
 312 {
 313         unsigned i, j;
 314
 315         for(i=0; i<compositor->nscreens; ++i)
 316                 for(j=0; j<compositor->screens[i].nwindows; ++j)
 317                         if(compositor->screens[i].windows[j].window==w)
 318                         {
 319                                 if(screen)
 320                                         *screen = &compositor->screens[i];
 321                                 return &compositor->screens[i].windows[j];
 322                         }
 323
 324         if(screen)
 325                 *screen = NULL;
 326         return NULL;
 327 }
 328
 329 void create_window_pixmap(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window)
 330 {
 331         int attribs[5];
 332         unsigned i;
 333
 334         if(window->pixmap)
 335         {
 336                 glXDestroyPixmap(compositor->display, window->glx_pixmap);
 337                 XFreePixmap(compositor->display, window->pixmap);
 338         }
 339
 340         i = 0;
 341         attribs[i++] = GLX_TEXTURE_TARGET_EXT;
 342         attribs[i++] = GLX_TEXTURE_2D_EXT;
 343         attribs[i++] = GLX_TEXTURE_FORMAT_EXT;
 344         attribs[i++] = GLX_TEXTURE_FORMAT_RGBA_EXT;
 345         attribs[i++] = None;
 346
 347         window->pixmap = XCompositeNameWindowPixmap(compositor->display, window->window);
 348         window->glx_pixmap = glXCreatePixmap(compositor->display, screen->fbconfig, window->pixmap, attribs);
 349 }
 350
 351 CompositedWindow *add_window(Compositor *compositor, CompositedScreen *screen, Window w)
 352 {
 353         CompositedWindow *window;
 354         XWindowAttributes win_attr;
 355
 356         if(w==screen->root || w==screen->overlay)
 357                 return NULL;
 358
 359         if(!XGetWindowAttributes(compositor->display, w, &win_attr))
 360         {
 361                 printf("XGetWindowAttributes failed; probably the window was already destroyed\n");
 362                 return NULL;
 363         }
 364         if(win_attr.class==InputOnly)
 365                 return NULL;
 366
 367         if(find_window(screen, w))
 368                 return NULL;
 369
 370         if(screen->nwindows==screen->windows_capacity)
 371         {
 372                 screen->windows = (CompositedWindow *)realloc(screen->windows, (screen->windows_capacity+1)*sizeof(CompositedWindow));
 373                 ++screen->windows_capacity;
 374         }
 375
 376         window = &screen->windows[screen->nwindows++];
 377
 378         window->window = w;
 379         window->x = win_attr.x;
 380         window->y = win_attr.y;
 381         window->width = win_attr.width;
 382         window->height = win_attr.height;
 383         window->border = win_attr.border_width;
 384         window->map_state = win_attr.map_state;
 385
 386         window->damage = XDamageCreate(compositor->display, window->window, XDamageReportNonEmpty);
 387         window->pixmap = None;
 388         window->glx_pixmap = None;
 389
 390         XCompositeRedirectWindow(compositor->display, window->window, CompositeRedirectManual);
 391         if(window->map_state==IsViewable)
 392                 create_window_pixmap(compositor, screen, window);
 393
 394         window->texture = create_2d_texture();
 395
 396         return window;
 397 }
 398
 399 void remove_window(Compositor *compositor, CompositedScreen *screen, CompositedWindow *window, int destroyed)
 400 {
 401         unsigned i;
 402
 403         glDeleteTextures(1, &window->texture);
 404         if(!destroyed)
 405         {
 406                 XDamageDestroy(compositor->display, window->damage);
 407                 if(window->pixmap)
 408                 {
 409                         glXDestroyPixmap(compositor->display, window->glx_pixmap);
 410                         XFreePixmap(compositor->display, window->pixmap);
 411                 }
 412                 XCompositeUnredirectWindow(compositor->display, window->window, CompositeRedirectManual);
 413         }
 414
 415         --screen->nwindows;
 416         for(i=window-screen->windows; i<screen->nwindows; ++i)
 417                 screen->windows[i] = screen->windows[i+1];
 418 }
 419
 420 CompositedWindow *reorder_window(CompositedScreen *screen, CompositedWindow *window, Window above)
 421 {
 422         unsigned i, j;
 423         CompositedWindow hold;
 424
 425         i = window-screen->windows;
 426         if(above)
 427         {
 428                 for(j=0; j<screen->nwindows; ++j)
 429                         if(screen->windows[j].window==above)
 430                                 break;
 431
 432                 if(j>=screen->nwindows || i==j+1)
 433                         return window;
 434
 435                 if(j<i)
 436                         ++j;
 437         }
 438         else
 439                 j = 0;
 440
 441         hold = *window;
 442         if(i<j)
 443         {
 444                 for(; i<j; ++i)
 445                         screen->windows[i] = screen->windows[i+1];
 446         }
 447         else
 448         {
 449                 for(; i>j; --i)
 450                         screen->windows[i] = screen->windows[i-1];
 451         }
 452         screen->windows[j] = hold;
 453
 454         return &screen->windows[j];
 455 }
 456
 457 CompositedScreen *find_screen_by_root(Compositor *compositor, Window root)
 458 {
 459         unsigned i;
 460
 461         for(i=0; i<compositor->nscreens; ++i)
 462                 if(compositor->screens[i].root==root)
 463                         return &compositor->screens[i];
 464
 465         return NULL;
 466 }
 467
 468 void update_monitor_vertices(CompositedScreen *screen, CompositedMonitor *monitor)
 469 {
 470         unsigned t;
 471         unsigned data_size;
 472         float *vertex_data;
 473         unsigned short *index_data;
 474         unsigned x, y;
 475         unsigned i;
 476         float aspect;
 477         float cyl_radius;
 478         float cyl_arc;
 479         float sin_ksv;
 480         float cos_ksv;
 481         float distance;
 482         float eye[3];
 483         float look[3];
 484
 485         t = monitor->tessellation;
 486
 487         data_size = (t+1)*(t+1)*4*sizeof(float);
 488         vertex_data = (float *)malloc(data_size);
 489
 490         aspect = (float)monitor->width/monitor->height;
 491
 492         if(monitor->cylinder_depth)
 493         {
 494                 cyl_radius = (monitor->cylinder_depth*monitor->cylinder_depth+0.25f)/(2.0f*monitor->cylinder_depth);
 495                 cyl_arc = 2.0f*asin(0.5f/cyl_radius);
 496         }
 497
 498         sin_ksv = monitor->keystone_vertical/sqrt(1.0f+monitor->keystone_vertical*monitor->keystone_vertical);
 499         cos_ksv = sqrt(1.0f-sin_ksv*sin_ksv);
 500         distance = monitor->perspective+sin_ksv*((sin_ksv>0)-monitor->vertical_center)/aspect;
 501
 502         eye[0] = 0.0f;
 503         eye[1] = (monitor->vertical_center-0.5f)/aspect+sin_ksv*distance;
 504         eye[2] = cos_ksv*distance;
 505
 506         look[0] = 0.0f;
 507         look[1] = -sin_ksv;
 508         look[2] = -cos_ksv;
 509
 510         for(y=0; y<=t; ++y)
 511                 for(x=0; x<=t; ++x)
 512                 {
 513                         float *v;
 514
 515                         v = vertex_data+(y*(t+1)+x)*3;
 516                         v[0] = (float)x/t-0.5f;
 517                         v[1] = ((float)y/t-0.5f)/aspect;
 518                         v[2] = 0;
 519                         if(monitor->cylinder_depth)
 520                         {
 521                                 v[2] = (1.0f-cos(v[0]*cyl_arc))*cyl_radius-monitor->cylinder_depth;
 522                                 v[0] = sin(v[0]*cyl_arc)*cyl_radius;
 523                         }
 524                 }
 525
 526         for(y=t; y<=t; --y)
 527                 for(x=t; x<=t; --x)
 528                 {
 529                         float *v;
 530                         float px, py, pz;
 531                         float scale;
 532
 533                         v = vertex_data+(y*(t+1)+x)*3;
 534                         px = v[0]-eye[0];
 535                         py = (v[0]-eye[0])*look[0] - (v[1]-eye[1])*look[2] + (v[2]-eye[2])*look[1];
 536                         pz = (v[0]-eye[0])*look[0] + (v[1]-eye[1])*look[1] + (v[2]-eye[2])*look[2];
 537                         scale = monitor->perspective/pz;
 538
 539                         v = vertex_data+(y*(t+1)+x)*4;
 540                         v[0] = px*scale+0.5f;
 541                         v[1] = py*aspect*scale+monitor->vertical_center;
 542                         v[2] = (monitor->x+(float)x*monitor->width/t)/screen->width;
 543                         v[3] = 1.0f-(monitor->y+(1.0f-(float)y/t)*monitor->height)/screen->height;
 544                 }
 545
 546         glBindBuffer(GL_ARRAY_BUFFER, monitor->vertex_buffer);
 547         glBufferData(GL_ARRAY_BUFFER, data_size, vertex_data, GL_STATIC_DRAW);
 548         glBindBuffer(GL_ARRAY_BUFFER, 0);
 549         free(vertex_data);
 550
 551         monitor->nelements = t*((t+1)*2+1)-1;
 552         data_size = monitor->nelements*sizeof(unsigned short);
 553         index_data = (unsigned short *)malloc(data_size);
 554         i = 0;
 555         for(y=0; y<t; ++y)
 556         {
 557                 if(y>0)
 558                         index_data[i++] = 0xFFFF;
 559                 for(x=0; x<=t; ++x)
 560                 {
 561                         index_data[i++] = (y+1)*(t+1)+x;
 562                         index_data[i++] = y*(t+1)+x;
 563                 }
 564         }
 565         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, monitor->index_buffer);
 566         glBufferData(GL_ELEMENT_ARRAY_BUFFER, data_size, index_data, GL_STATIC_DRAW);
 567         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 568         free(index_data);
 569 }
 570
 571 int initialize_monitor(Compositor *compositor, CompositedScreen *screen, XRRScreenResources *xrr_res, unsigned index)
 572 {
 573         CompositedMonitor *monitor;
 574         XRROutputInfo *output;
 575         int namelen;
 576         XRRCrtcInfo *crtc;
 577         unsigned buffers[2];
 578         unsigned stride;
 579
 580         monitor = &screen->monitors[index];
 581
 582         output = XRRGetOutputInfo(compositor->display, xrr_res, xrr_res->outputs[index]);
 583         namelen = strlen(output->name);
 584         monitor->name = (char *)malloc(namelen+1);
 585         strcpy(monitor->name, output->name);
 586         monitor->enabled = !!output->crtc;
 587         if(!monitor->enabled)
 588         {
 589                 XRRFreeOutputInfo(output);
 590                 return 1;
 591         }
 592
 593         crtc = XRRGetCrtcInfo(compositor->display, xrr_res, output->crtc);
 594         monitor->x = crtc->x;
 595         monitor->y = crtc->y;
 596         monitor->width = crtc->width;
 597         monitor->height = crtc->height;
 598         XRRFreeCrtcInfo(crtc);
 599         XRRFreeOutputInfo(output);
 600
 601         monitor->keystone_vertical = 0.0f;
 602         monitor->cylinder_depth = 0.0f;
 603         monitor->vertical_center = 0.5f;
 604         monitor->perspective = 1.0f;
 605
 606         glGenBuffers(2, buffers);
 607         monitor->vertex_buffer = buffers[0];
 608         monitor->index_buffer = buffers[1];
 609
 610         monitor->tessellation = 50;
 611         update_monitor_vertices(screen, monitor);
 612         stride = 4*sizeof(float);
 613
 614         glGenVertexArrays(1, &monitor->vertex_array);
 615         glBindVertexArray(monitor->vertex_array);
 616         glBindBuffer(GL_ARRAY_BUFFER, monitor->vertex_buffer);
 617         glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, stride, NULL);
 618         glEnableVertexAttribArray(0);
 619         glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, stride, (void *)(2*sizeof(float)));
 620         glEnableVertexAttribArray(1);
 621         glBindBuffer(GL_ARRAY_BUFFER, 0);
 622         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, monitor->index_buffer);
 623         glBindVertexArray(0);
 624
 625         return 1;
 626 }
 627
 628 CompositedMonitor *find_monitor_by_name(CompositedScreen *screen, char *name)
 629 {
 630         unsigned i;
 631
 632         for(i=0; i<screen->nmonitors; ++i)
 633                 if(!strcmp(screen->monitors[i].name, name))
 634                         return &screen->monitors[i];
 635
 636         return NULL;
 637 }
 638
 639 void update_geometry_correction(Compositor *compositor, CompositedScreen *screen)
 640 {
 641         Atom prop_type;
 642         int prop_format;
 643         unsigned long overflow;
 644         unsigned long names_length;
 645         char *names;
 646         unsigned long values_length;
 647         short *values;
 648         char *name_ptr;
 649         unsigned i;
 650
 651         XGetWindowProperty(compositor->display, screen->root, compositor->monitors_atom, 0, 64, False, XA_STRING,
 652                 &prop_type, &prop_format, &names_length, &overflow, (unsigned char **)&names);
 653         if(prop_type!=XA_STRING || prop_format!=8)
 654                 return;
 655
 656         XGetWindowProperty(compositor->display, screen->root, compositor->correction_atom, 0, 64, False, XA_INTEGER,
 657                 &prop_type, &prop_format, &values_length, &overflow, (unsigned char **)&values);
 658         if(prop_type!=XA_INTEGER || prop_format!=16)
 659         {
 660                 XFree(names);
 661                 return;
 662         }
 663
 664         use_gl(compositor, screen);
 665
 666         name_ptr = names;
 667         for(i=0; i*4<values_length; ++i)
 668         {
 669                 CompositedMonitor *monitor;
 670
 671                 if(name_ptr>=names+names_length)
 672                         break;
 673
 674                 monitor = find_monitor_by_name(screen, name_ptr);
 675                 if(monitor)
 676                 {
 677                         monitor->keystone_vertical = values[i*4]/10000.0f;
 678                         monitor->cylinder_depth = values[i*4+1]/10000.0f;
 679                         monitor->vertical_center = values[i*4+2]/10000.0f;
 680                         monitor->perspective = values[i*4+3]/10000.0f;
 681
 682                         if(monitor->enabled)
 683                                 update_monitor_vertices(screen, monitor);
 684                 }
 685
 686                 name_ptr += strlen(name_ptr)+1;
 687         }
 688
 689         XFree(names);
 690         XFree(values);
 691 }
 692
 693 int initialize_screen(Compositor *compositor, unsigned number)
 694 {
 695         CompositedScreen *screen;
 696         const char *extensions;
 697         Window dummy_root;
 698         int x, y;
 699         unsigned border;
 700         unsigned depth;
 701         XRRScreenResources *xrr_res;
 702         Window dummy_parent;
 703         Window *children;
 704         unsigned nchildren;
 705         unsigned i;
 706
 707         screen = &compositor->screens[number];
 708         screen->number = number;
 709
 710         extensions = glXQueryExtensionsString(compositor->display, screen->number);
 711         if(!strstr(extensions, "GLX_ARB_create_context"))
 712                 return with_error("GLX_ARB_create_context is required");
 713         if(!strstr(extensions, "GLX_EXT_texture_from_pixmap"))
 714                 return with_error("GLX_EXT_texture_from_pixmap is required");
 715
 716         screen->root = RootWindow(compositor->display, screen->number);
 717         XSelectInput(compositor->display, screen->root, SubstructureNotifyMask|PropertyChangeMask);
 718         screen->overlay = XCompositeGetOverlayWindow(compositor->display, screen->root);
 719         XGetGeometry(compositor->display, screen->overlay, &dummy_root, &x, &y, &screen->width, &screen->height, &border, &depth);
 720         XShapeCombineRectangles(compositor->display, screen->overlay, ShapeInput, 0, 0, NULL, 0, ShapeSet, Unsorted);
 721
 722         if(!initialize_gl(compositor, screen))
 723                 return 0;
 724
 725         if(!create_gl_resources(compositor, screen))
 726                 return 0;
 727
 728         xrr_res = XRRGetScreenResources(compositor->display, screen->root);
 729         screen->nmonitors = xrr_res->noutput;
 730         screen->monitors = (CompositedMonitor *)malloc(screen->nmonitors*sizeof(CompositedMonitor));
 731         for(i=0; i<screen->nmonitors; ++i)
 732                 if(!initialize_monitor(compositor, screen, xrr_res, i))
 733                         return 0;
 734         XRRFreeScreenResources(xrr_res);
 735
 736         update_geometry_correction(compositor, screen);
 737
 738         XQueryTree(compositor->display, screen->root, &dummy_root, &dummy_parent, &children, &nchildren);
 739
 740         screen->windows = (CompositedWindow *)malloc(nchildren*sizeof(CompositedWindow));
 741         screen->nwindows = 0;
 742         screen->windows_capacity = nchildren;
 743
 744         for(i=0; i<nchildren; ++i)
 745                 add_window(compositor, screen, children[i]);
 746
 747         XFree(children);
 748
 749         screen->dirty = 1;
 750
 751         return 1;
 752 }
 753
 754 int initialize_compositor(Compositor *compositor)
 755 {
 756         int event_base;
 757         int error_base;
 758         int major_ver;
 759         int minor_ver;
 760         unsigned i;
 761
 762         compositor->display = XOpenDisplay(NULL);
 763         if(!compositor->display)
 764                 return with_error("Could not open X display");
 765
 766         XSetErrorHandler(&x_error_handler);
 767
 768         if(!XCompositeQueryExtension(compositor->display, &event_base, &error_base))
 769                 return with_error("XComposite is required but was not found");
 770         else if(!XCompositeQueryVersion(compositor->display, &major_ver, &minor_ver))
 771                 return with_error("Cannot determine XComposite version");
 772         else if(major_ver==0 && minor_ver<3)
 773                 return with_error("XComposite 0.3 or later is required");
 774
 775         if(!glXQueryExtension(compositor->display, &event_base, &error_base))
 776                 return with_error("GLX is required but was not found");
 777         else if(!glXQueryVersion(compositor->display, &major_ver, &minor_ver))
 778                 return with_error("Cannot determine GLX version");
 779         else if(major_ver<1 || (major_ver==1 && minor_ver<4))
 780                 return with_error("GLX 1.4 or later is required");
 781
 782         if(!XDamageQueryExtension(compositor->display, &compositor->damage_event, &error_base))
 783                 return with_error("XDamage is required but was not found");
 784         else if(!XDamageQueryVersion(compositor->display, &major_ver, &minor_ver))
 785                 return with_error("Cannot determine XDamage version");
 786         else if(major_ver<1)
 787                 return with_error("XDamage 1.0 or later is required");
 788
 789         if(!XShapeQueryExtension(compositor->display, &event_base, &error_base))
 790                 return with_error("XShape is required but was not found");
 791         else if(!XShapeQueryVersion(compositor->display, &major_ver, &minor_ver))
 792                 return with_error("Cannot determine XShape version");
 793         else if(major_ver<1 || (major_ver==1 && minor_ver<1))
 794                 return with_error("XShape 1.1 or later is required");
 795
 796         if(!XRRQueryExtension(compositor->display, &event_base, &error_base))
 797                 return with_error("XRandR is required but was not found");
 798         else if(!XRRQueryVersion(compositor->display, &major_ver, &minor_ver))
 799                 return with_error("Cannot determine XRandR version");
 800         else if(major_ver<1 || (major_ver==1 && minor_ver<2))
 801                 return with_error("XRandR 1.2 or later is required");
 802
 803         compositor->glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((unsigned char *)"glXCreateContextAttribsARB");
 804         compositor->glXBindTexImageEXT = (PFNGLXBINDTEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXBindTexImageEXT");
 805         compositor->glXReleaseTexImageEXT = (PFNGLXRELEASETEXIMAGEEXTPROC)glXGetProcAddress((unsigned char *)"glXReleaseTexImageEXT");
 806
 807         compositor->correction_atom = XInternAtom(compositor->display, "GEOMETRY_CORRECTION", False);
 808         compositor->monitors_atom = XInternAtom(compositor->display, "GEOMETRY_CORRECTION_MONITORS", False);
 809
 810         compositor->nscreens = ScreenCount(compositor->display);
 811         compositor->screens = (CompositedScreen *)malloc(compositor->nscreens*sizeof(CompositedScreen));
 812         for(i=0; i<compositor->nscreens; ++i)
 813                 if(!initialize_screen(compositor, i))
 814                         return 0;
 815
 816         compositor->dirty = 1;
 817
 818         return 1;
 819 }
 820
 821 void shutdown_screen(Compositor *compositor, CompositedScreen *screen)
 822 {
 823         unsigned i;
 824
 825         use_gl(compositor, screen);
 826
 827         for(i=0; i<screen->nwindows; ++i)
 828         {
 829                 glDeleteTextures(1, &screen->windows[i].texture);
 830                 if(screen->windows[i].pixmap)
 831                 {
 832                         glXDestroyPixmap(compositor->display, screen->windows[i].glx_pixmap);
 833                         XFreePixmap(compositor->display, screen->windows[i].pixmap);
 834                         XDamageDestroy(compositor->display, screen->windows[i].damage);
 835                 }
 836         }
 837
 838         for(i=0; i<screen->nmonitors; ++i)
 839         {
 840                 free(screen->monitors[i].name);
 841                 if(screen->monitors[i].enabled)
 842                 {
 843                         glDeleteBuffers(1, &screen->monitors[i].vertex_buffer);
 844                         glDeleteBuffers(1, &screen->monitors[i].index_buffer);
 845                         glDeleteVertexArrays(1, &screen->monitors[i].vertex_array);
 846                 }
 847         }
 848
 849         glDeleteBuffers(1, &screen->window_vertex_buffer);
 850         glDeleteVertexArrays(1, &screen->window_vertex_array);
 851         glDeleteFramebuffers(1, &screen->framebuffer);
 852         glDeleteTextures(1, &screen->fb_texture);
 853         glDeleteProgram(screen->program);
 854         glDeleteShader(screen->shaders[0]);
 855         glDeleteShader(screen->shaders[1]);
 856
 857         glXMakeContextCurrent(compositor->display, 0, 0, NULL);
 858         glXDestroyContext(compositor->display, screen->glx_context);
 859         glXDestroyWindow(compositor->display, screen->glx_window);
 860         XDestroyWindow(compositor->display, screen->render_window);
 861
 862         XCompositeReleaseOverlayWindow(compositor->display, screen->overlay);
 863
 864         free(screen->windows);
 865         free(screen->monitors);
 866 }
 867
 868 void shutdown_compositor(Compositor *compositor)
 869 {
 870         unsigned i;
 871
 872         for(i=0; i<compositor->nscreens; ++i)
 873                 shutdown_screen(compositor, &compositor->screens[i]);
 874         free(compositor->screens);
 875
 876         XCloseDisplay(compositor->display);
 877 }
 878
 879 void mark_dirty(Compositor *compositor, CompositedScreen *screen)
 880 {
 881         compositor->dirty = 1;
 882         screen->dirty = 1;
 883 }
 884
 885 void process_create_window_event(Compositor *compositor, XCreateWindowEvent *event)
 886 {
 887         CompositedScreen *screen;
 888
 889         if((screen = find_screen_by_root(compositor, event->parent)))
 890                 add_window(compositor, screen, event->window);
 891 }
 892
 893 void process_destroy_window_event(Compositor *compositor, XDestroyWindowEvent *event)
 894 {
 895         CompositedScreen *screen;
 896         CompositedWindow *window;
 897
 898         if((screen = find_screen_by_root(compositor, event->event)))
 899                 if((window = find_window(screen, event->window)))
 900                         remove_window(compositor, screen, window, 1);
 901 }
 902
 903 void process_map_event(Compositor *compositor, XMapEvent *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         window = find_window(screen, event->window);
 913         if(!window)
 914                 return;
 915
 916         window->map_state = IsViewable;
 917         create_window_pixmap(compositor, screen, window);
 918
 919         mark_dirty(compositor, screen);
 920 }
 921
 922 void process_unmap_event(Compositor *compositor, XUnmapEvent *event)
 923 {
 924         CompositedScreen *screen;
 925         CompositedWindow *window;
 926
 927         screen = find_screen_by_root(compositor, event->event);
 928         if(!screen)
 929                 return;
 930
 931         window = find_window(screen, event->window);
 932         if(window)
 933                 window->map_state = IsUnviewable;
 934
 935         mark_dirty(compositor, screen);
 936 }
 937
 938 void process_reparent_event(Compositor *compositor, XReparentEvent *event)
 939 {
 940         CompositedScreen *screen;
 941         CompositedWindow *window;
 942
 943         screen = find_screen_by_root(compositor, event->event);
 944         if(!screen)
 945                 return;
 946
 947         if(event->parent==screen->root)
 948                 window = add_window(compositor, screen, event->window);
 949         else
 950         {
 951                 window = find_window(screen, event->window);
 952                 if(!window)
 953                         return;
 954
 955                 remove_window(compositor, screen, window, 0);
 956         }
 957
 958         if(window && window->map_state==IsViewable)
 959                 mark_dirty(compositor, screen);
 960 }
 961
 962 void process_configure_event(Compositor *compositor, XConfigureEvent *event)
 963 {
 964         CompositedScreen *screen;
 965         CompositedWindow *window;
 966
 967         screen = find_screen_by_root(compositor, event->event);
 968         if(!screen)
 969                 return;
 970
 971         window = find_window(screen, event->window);
 972         if(!window)
 973                 return;
 974
 975         window->x = event->x;
 976         window->y = event->y;
 977         if((unsigned)event->width!=window->width || (unsigned)event->height!=window->height || (unsigned)event->border_width!=window->border)
 978         {
 979                 window->width = event->width;
 980                 window->height = event->height;
 981                 window->border = event->border_width;
 982                 create_window_pixmap(compositor, screen, window);
 983         }
 984         reorder_window(screen, window, event->above);
 985
 986         if(window->map_state==IsViewable)
 987                 mark_dirty(compositor, screen);
 988 }
 989
 990 void process_property_event(Compositor *compositor, XPropertyEvent *event)
 991 {
 992         CompositedScreen *screen;
 993
 994         if(event->atom!=compositor->correction_atom)
 995                 return;
 996
 997         screen = find_screen_by_root(compositor, event->window);
 998         if(!screen)
 999                 return;
1000
1001         update_geometry_correction(compositor, screen);
1002 }
1003
1004 void process_damage_event(Compositor *compositor, XDamageNotifyEvent *event)
1005 {
1006         CompositedScreen *screen;
1007         CompositedWindow *window;
1008
1009         window = find_window_global(compositor, event->drawable, &screen);
1010         if(window && window->map_state==IsViewable)
1011                 mark_dirty(compositor, screen);
1012 }
1013
1014 int process_event(Compositor *compositor)
1015 {
1016         XEvent event;
1017         if(compositor->dirty)
1018         {
1019                 if(!XCheckMaskEvent(compositor->display, -1, &event))
1020                         return 0;
1021         }
1022         else
1023                 XNextEvent(compositor->display, &event);
1024
1025         switch(event.type)
1026         {
1027         case CreateNotify:
1028                 process_create_window_event(compositor, &event.xcreatewindow);
1029                 break;
1030         case DestroyNotify:
1031                 process_destroy_window_event(compositor, &event.xdestroywindow);
1032                 break;
1033         case MapNotify:
1034                 process_map_event(compositor, &event.xmap);
1035                 break;
1036         case UnmapNotify:
1037                 process_unmap_event(compositor, &event.xunmap);
1038                 break;
1039         case ReparentNotify:
1040                 process_reparent_event(compositor, &event.xreparent);
1041                 break;
1042         case ConfigureNotify:
1043                 process_configure_event(compositor, &event.xconfigure);
1044                 break;
1045         case PropertyNotify:
1046                 process_property_event(compositor, &event.xproperty);
1047                 break;
1048         default:
1049                 if(event.type==compositor->damage_event+XDamageNotify)
1050                         process_damage_event(compositor, (XDamageNotifyEvent *)&event);
1051                 else
1052                         printf("Event %d\n", event.type);
1053         }
1054
1055         return 1;
1056 }
1057
1058 void refresh_screen(Compositor *compositor, CompositedScreen *screen)
1059 {
1060         unsigned i;
1061
1062         use_gl(compositor, screen);
1063
1064         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, screen->framebuffer);
1065
1066         glClearColor(0.5f, 0.5f, 0.5f, 0.0f);
1067         glClear(GL_COLOR_BUFFER_BIT);
1068
1069         glUseProgram(screen->program);
1070         glBindVertexArray(screen->window_vertex_array);
1071         for(i=0; i<screen->nwindows; ++i)
1072         {
1073                 CompositedWindow *window = &screen->windows[i];
1074                 if(window->map_state!=IsViewable)
1075                         continue;
1076
1077                 XDamageSubtract(compositor->display, window->damage, None, None);
1078
1079                 glBindTexture(GL_TEXTURE_2D, window->texture);
1080                 compositor->glXBindTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT, NULL);
1081                 glUniform4f(screen->geometry_loc,
1082                         (float)window->x/screen->width, 1.0f-(float)(window->y+window->height)/screen->height,
1083                         (float)(window->width+2*window->border)/screen->width, (float)(window->height+2*window->border)/screen->height);
1084                 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
1085                 compositor->glXReleaseTexImageEXT(compositor->display, window->glx_pixmap, GLX_FRONT_LEFT_EXT);
1086         }
1087
1088         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
1089         glClearColor(0.5f, 0.0f, 0.5f, 0.0f);
1090         glClear(GL_COLOR_BUFFER_BIT);
1091         glBindTexture(GL_TEXTURE_2D, screen->fb_texture);
1092         glEnable(GL_PRIMITIVE_RESTART);
1093         glPrimitiveRestartIndex(0xFFFF);
1094
1095         for(i=0; i<screen->nmonitors; ++i)
1096         {
1097                 CompositedMonitor *monitor = &screen->monitors[i];
1098                 if(!monitor->enabled)
1099                         continue;
1100
1101                 glUniform4f(screen->geometry_loc,
1102                         (float)monitor->x/screen->width, 1.0f-(float)(monitor->y+monitor->height)/screen->height,
1103                         (float)monitor->width/screen->width, (float)monitor->height/screen->height);
1104
1105                 glBindVertexArray(monitor->vertex_array);
1106                 glDrawElements(GL_TRIANGLE_STRIP, monitor->nelements, GL_UNSIGNED_SHORT, NULL);
1107         }
1108
1109         glBindVertexArray(0);
1110
1111         glXSwapBuffers(compositor->display, screen->glx_window);
1112
1113         screen->dirty = 0;
1114 }
1115
1116 void refresh_all_screens(Compositor *compositor)
1117 {
1118         unsigned i;
1119
1120         for(i=0; i<compositor->nscreens; ++i)
1121         {
1122                 CompositedScreen *screen = &compositor->screens[i];
1123                 if(screen->dirty)
1124                         refresh_screen(compositor, screen);
1125         }
1126
1127         compositor->dirty = 0;
1128 }
1129
1130 void sighandler(int sig)
1131 {
1132         terminate_requested = 1;
1133         (void)sig;
1134 }
1135
1136 int main()
1137 {
1138         Compositor compositor;
1139
1140         signal(SIGINT, &sighandler);
1141         signal(SIGTERM, &sighandler);
1142
1143         if(!initialize_compositor(&compositor))
1144                 return 1;
1145
1146         while(!terminate_requested)
1147         {
1148                 if(!process_event(&compositor))
1149                         refresh_all_screens(&compositor);
1150         }
1151
1152         shutdown_compositor(&compositor);
1153
1154         return 0;
1155 }