git.mutantstargoat.com Git - laserbrain_demo/blob - src/app.cc

   1 #include <stdio.h>
   2 #include <assert.h>
   3 #include <goatvr.h>
   4 #include "app.h"
   5 #include "opengl.h"
   6 #include "sdr.h"
   7 #include "texture.h"
   8 #include "mesh.h"
   9 #include "meshgen.h"
  10 #include "scene.h"
  11 #include "metascene.h"
  12 #include "datamap.h"
  13 #include "ui.h"
  14 #include "opt.h"
  15 #include "post.h"
  16 #include "renderer.h"
  17 #include "avatar.h"
  18 #include "vrinput.h"
  19 #include "exman.h"
  20 #include "blob_exhibit.h"
  21 #include "dbg_gui.h"
  22
  23 #define NEAR_CLIP       5.0
  24 #define FAR_CLIP        10000.0
  25
  26 static void draw_scene();
  27 static void toggle_flight();
  28 static void calc_framerate();
  29
  30 long time_msec;
  31 int win_width, win_height;
  32 float win_aspect;
  33 bool fb_srgb;
  34 bool opt_gear_wireframe;
  35
  36 TextureSet texman;
  37 SceneSet sceneman;
  38
  39 unsigned int sdr_ltmap, sdr_ltmap_notex;
  40
  41 static Avatar avatar;
  42
  43 static float cam_dist = 0.0;
  44 static float floor_y;   // last floor height
  45 static float user_eye_height = 165;
  46
  47 static float walk_speed = 300.0f;
  48 static float mouse_speed = 0.5f;
  49 static bool show_walk_mesh, noclip = false;
  50
  51 static bool have_headtracking, have_handtracking, should_swap;
  52
  53 static int prev_mx, prev_my;
  54 static bool bnstate[8];
  55 static bool keystate[256];
  56 static bool gpad_bnstate[64];
  57 static Vec2 joy_move, joy_look;
  58 static float joy_deadzone = 0.01;
  59
  60 static float framerate;
  61
  62 static Mat4 view_matrix, mouse_view_matrix, proj_matrix;
  63 static MetaScene *mscn;
  64 static unsigned int sdr_post_gamma;
  65
  66 static long prev_msec;
  67
  68 static ExhibitManager *exman;
  69 static BlobExhibit *blobs;
  70 static bool show_blobs;
  71
  72 static Renderer *rend;
  73
  74 static bool show_debug_gui;
  75
  76
  77 bool app_init(int argc, char **argv)
  78 {
  79         if(!init_options(argc, argv, "demo.conf")) {
  80                 return false;
  81         }
  82         app_resize(opt.width, opt.height);
  83         app_fullscreen(opt.fullscreen);
  84
  85         if(opt.vr) {
  86                 if(goatvr_init() == -1) {
  87                         return false;
  88                 }
  89                 goatvr_set_origin_mode(GOATVR_HEAD);
  90                 goatvr_set_units_scale(100.0f);
  91
  92                 goatvr_startvr();
  93                 should_swap = goatvr_should_swap() != 0;
  94                 user_eye_height = goatvr_get_eye_height();
  95                 have_headtracking = goatvr_have_headtracking();
  96                 have_handtracking = goatvr_have_handtracking();
  97
  98                 goatvr_recenter();
  99         }
 100
 101         if(fb_srgb) {
 102                 int srgb_capable;
 103                 glGetIntegerv(GL_FRAMEBUFFER_SRGB_CAPABLE_EXT, &srgb_capable);
 104                 printf("Framebuffer %s sRGB-capable\n", srgb_capable ? "is" : "is not");
 105                 if(srgb_capable) {
 106                         glEnable(GL_FRAMEBUFFER_SRGB);
 107                 } else {
 108                         fb_srgb = 0;
 109                 }
 110         }
 111
 112         glEnable(GL_MULTISAMPLE);
 113         glEnable(GL_DEPTH_TEST);
 114         glEnable(GL_CULL_FACE);
 115         glEnable(GL_LIGHTING);
 116         glEnable(GL_NORMALIZE);
 117
 118         if(!init_debug_gui()) {
 119                 return false;
 120         }
 121
 122         Mesh::use_custom_sdr_attr = false;
 123
 124         float ambient[] = {0.0, 0.0, 0.0, 0.0};
 125         glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambient);
 126
 127         glClearColor(1, 1, 1, 1);
 128
 129         init_audio();
 130
 131         if(!init_vrhands()) {
 132                 return false;
 133         }
 134
 135         mscn = new MetaScene;
 136         if(!mscn->load(opt.scenefile ? opt.scenefile : "data/museum.scene")) {
 137                 return false;
 138         }
 139
 140         avatar.pos = mscn->start_pos;
 141         Vec3 dir = rotate(Vec3(0, 0, 1), mscn->start_rot);
 142         dir.y = 0;
 143         avatar.body_rot = rad_to_deg(acos(dot(dir, Vec3(0, 0, 1))));
 144
 145         exman = new ExhibitManager;
 146         if(!exman->load(mscn, "data/exhibits")) {
 147                 //return false;
 148         }
 149
 150         blobs = new BlobExhibit;
 151         blobs->node = new SceneNode;
 152         blobs->init();
 153         blobs->node->set_position(Vec3(-680, 160, -100));
 154         blobs->node->set_scaling(Vec3(28, 28, 28));
 155         blobs->node->update(0);
 156
 157         exman->add(blobs);
 158
 159         if(!(sdr_ltmap_notex = create_program_load("sdr/lightmap.v.glsl", "sdr/lightmap-notex.p.glsl"))) {
 160                 return false;
 161         }
 162         set_uniform_int(sdr_ltmap_notex, "texmap", MTL_TEX_DIFFUSE);
 163         set_uniform_int(sdr_ltmap_notex, "lightmap", MTL_TEX_LIGHTMAP);
 164
 165         if(!(sdr_ltmap = create_program_load("sdr/lightmap.v.glsl", "sdr/lightmap-tex.p.glsl"))) {
 166                 return false;
 167         }
 168         set_uniform_int(sdr_ltmap, "texmap", MTL_TEX_DIFFUSE);
 169         set_uniform_int(sdr_ltmap, "lightmap", MTL_TEX_LIGHTMAP);
 170
 171         if(!fb_srgb) {
 172                 sdr_post_gamma = create_program_load("sdr/post_gamma.v.glsl", "sdr/post_gamma.p.glsl");
 173         }
 174
 175         rend = new Renderer;
 176         rend->set_scene(mscn);
 177
 178         glUseProgram(0);
 179
 180         if(opt.vr || opt.fullscreen) {
 181                 app_grab_mouse(true);
 182         }
 183
 184         if(mscn->music && opt.music) {
 185                 mscn->music->play(AUDIO_PLAYMODE_LOOP);
 186         }
 187         return true;
 188 }
 189
 190 void app_cleanup()
 191 {
 192         if(mscn->music) {
 193                 mscn->music->stop();
 194         }
 195         destroy_audio();
 196
 197         app_grab_mouse(false);
 198         if(opt.vr) {
 199                 goatvr_shutdown();
 200         }
 201         destroy_vrhands();
 202
 203         delete rend;
 204
 205         delete exman;
 206
 207         texman.clear();
 208         sceneman.clear();
 209
 210         cleanup_debug_gui();
 211 }
 212
 213 static bool constrain_walk_mesh(const Vec3 &v, Vec3 *newv)
 214 {
 215         Mesh *wm = mscn->walk_mesh;
 216         if(!wm) {
 217                 *newv = v;
 218                 return true;
 219         }
 220
 221         Ray downray = Ray(v, Vec3(0, -1, 0));
 222         HitPoint hit;
 223         if(mscn->walk_mesh->intersect(downray, &hit)) {
 224                 *newv = hit.pos;
 225                 newv->y += user_eye_height;
 226                 return true;
 227         }
 228         return false;
 229 }
 230
 231 static void update(float dt)
 232 {
 233         texman.update();
 234         sceneman.update();
 235
 236         mscn->update(dt);
 237         exman->update(dt);
 238
 239         float speed = walk_speed * dt;
 240         Vec3 dir;
 241
 242         // joystick
 243         float jdeadsq = joy_deadzone * joy_deadzone;
 244         float jmove_lensq = length_sq(joy_move);
 245         float jlook_lensq = length_sq(joy_look);
 246
 247         if(jmove_lensq > jdeadsq) {
 248                 float len = sqrt(jmove_lensq);
 249                 jmove_lensq -= jdeadsq;
 250
 251                 float mag = len * len;
 252                 dir.x += mag * joy_move.x / len * 2.0 * speed;
 253                 dir.z += mag * joy_move.y / len * 2.0 * speed;
 254         }
 255         if(jlook_lensq > jdeadsq) {
 256                 float len = sqrt(jlook_lensq);
 257                 jlook_lensq -= jdeadsq;
 258
 259                 float mag = len * len;
 260                 avatar.body_rot += mag * joy_look.x / len * 200.0 * dt;
 261                 avatar.head_alt += mag * joy_look.y / len * 100.0 * dt;
 262                 if(avatar.head_alt < -90.0f) avatar.head_alt = -90.0f;
 263                 if(avatar.head_alt > 90.0f) avatar.head_alt = 90.0f;
 264         }
 265
 266         // keyboard move
 267         if(keystate[(int)'w']) {
 268                 dir.z -= speed;
 269         }
 270         if(keystate[(int)'s']) {
 271                 dir.z += speed;
 272         }
 273         if(keystate[(int)'d']) {
 274                 dir.x += speed;
 275         }
 276         if(keystate[(int)'a']) {
 277                 dir.x -= speed;
 278         }
 279         if(keystate[(int)'q'] || gpad_bnstate[GPAD_UP]) {
 280                 avatar.pos.y += speed;
 281         }
 282         if(keystate[(int)'z'] || gpad_bnstate[GPAD_DOWN]) {
 283                 avatar.pos.y -= speed;
 284         }
 285
 286         float theta = M_PI * avatar.body_rot / 180.0f;
 287         Vec3 newpos;
 288         newpos.x = avatar.pos.x + cos(theta) * dir.x - sin(theta) * dir.z;
 289         newpos.y = avatar.pos.y;
 290         newpos.z = avatar.pos.z + sin(theta) * dir.x + cos(theta) * dir.z;
 291
 292         if(noclip) {
 293                 avatar.pos = newpos;
 294         } else {
 295                 if(!constrain_walk_mesh(newpos, &avatar.pos)) {
 296                         float dtheta = M_PI / 32.0;
 297                         float theta = dtheta;
 298                         Vec2 dir2d = newpos.xz() - avatar.pos.xz();
 299
 300                         for(int i=0; i<16; i++) {
 301                                 Vec2 dvec = rotate(dir2d, theta);
 302                                 Vec3 pos = avatar.pos + Vec3(dvec.x, 0, dvec.y);
 303                                 if(constrain_walk_mesh(pos, &avatar.pos)) {
 304                                         break;
 305                                 }
 306                                 dvec = rotate(dir2d, -theta);
 307                                 pos = avatar.pos + Vec3(dvec.x, 0, dvec.y);
 308                                 if(constrain_walk_mesh(pos, &avatar.pos)) {
 309                                         break;
 310                                 }
 311                                 theta += dtheta;
 312                         }
 313                 }
 314                 floor_y = avatar.pos.y - user_eye_height;
 315         }
 316
 317         // TODO move to avatar
 318         // calculate mouselook view matrix
 319         mouse_view_matrix = Mat4::identity;
 320         mouse_view_matrix.pre_translate(0, 0, -cam_dist);
 321         if(!have_headtracking) {
 322                 mouse_view_matrix.pre_rotate_x(deg_to_rad(avatar.head_alt));
 323         }
 324         mouse_view_matrix.pre_rotate_y(deg_to_rad(avatar.body_rot));
 325         mouse_view_matrix.pre_translate(-avatar.pos.x, -avatar.pos.y, -avatar.pos.z);
 326
 327         // update hand-tracking
 328         if(have_handtracking) {
 329                 update_vrhands(&avatar);
 330         }
 331 }
 332
 333 static void set_light(int idx, const Vec3 &pos, const Vec3 &color)
 334 {
 335         unsigned int lt = GL_LIGHT0 + idx;
 336         float posv[] = { pos.x, pos.y, pos.z, 1 };
 337         float colv[] = { color.x, color.y, color.z, 1 };
 338
 339         glEnable(lt);
 340         glLightfv(lt, GL_POSITION, posv);
 341         glLightfv(lt, GL_DIFFUSE, colv);
 342         glLightfv(lt, GL_SPECULAR, colv);
 343 }
 344
 345 void app_display()
 346 {
 347         float dt = (float)(time_msec - prev_msec) / 1000.0f;
 348         prev_msec = time_msec;
 349
 350         if(show_debug_gui) {
 351                 ImGui::GetIOPtr()->DeltaTime = dt;
 352                 ImGui::NewFrame();
 353
 354                 ImGui::ShowTestWindow();
 355         }
 356
 357         if(opt.vr) {
 358                 // VR mode
 359                 goatvr_draw_start();
 360                 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 361
 362                 update(dt);
 363
 364                 for(int i=0; i<2; i++) {
 365                         // for each eye
 366                         goatvr_draw_eye(i);
 367
 368                         proj_matrix = goatvr_projection_matrix(i, NEAR_CLIP, FAR_CLIP);
 369                         glMatrixMode(GL_PROJECTION);
 370                         glLoadMatrixf(proj_matrix[0]);
 371
 372                         view_matrix = mouse_view_matrix * Mat4(goatvr_view_matrix(i));
 373                         glMatrixMode(GL_MODELVIEW);
 374                         glLoadMatrixf(view_matrix[0]);
 375
 376                         draw_scene();
 377                         if(have_handtracking) {
 378                                 draw_vrhands();
 379                         }
 380
 381                         if(show_debug_gui) {
 382                                 ImGui::Render();
 383                         }
 384                 }
 385                 goatvr_draw_done();
 386
 387                 if(should_swap) {
 388                         app_swap_buffers();
 389                 }
 390
 391         } else {
 392                 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 393
 394                 update(dt);
 395
 396                 proj_matrix.perspective(deg_to_rad(50.0), win_aspect, NEAR_CLIP, FAR_CLIP);
 397                 glMatrixMode(GL_PROJECTION);
 398                 glLoadMatrixf(proj_matrix[0]);
 399
 400                 view_matrix = mouse_view_matrix;
 401                 glMatrixMode(GL_MODELVIEW);
 402                 glLoadMatrixf(view_matrix[0]);
 403
 404                 draw_scene();
 405
 406                 if(!fb_srgb && sdr_post_gamma) {
 407                         slow_post(sdr_post_gamma);
 408                         glUseProgram(0);
 409                 }
 410
 411                 if(show_debug_gui) {
 412                         ImGui::Render();
 413                 }
 414                 app_swap_buffers();
 415         }
 416         assert(glGetError() == GL_NO_ERROR);
 417
 418         calc_framerate();
 419 }
 420
 421
 422 static void draw_scene()
 423 {
 424         static const Vec3 lpos[] = { Vec3(-50, 75, 100), Vec3(100, 0, 30), Vec3(-10, -10, 60) };
 425         set_light(0, lpos[0], Vec3(1.0, 0.8, 0.7) * 0.8);
 426         set_light(1, lpos[1], Vec3(0.6, 0.7, 1.0) * 0.6);
 427         set_light(2, lpos[2], Vec3(0.8, 1.0, 0.8) * 0.3);
 428
 429         rend->draw();
 430
 431         if(show_blobs) {
 432                 blobs->draw();
 433         }
 434
 435         /*
 436         if(have_handtracking) {
 437                 Mat4 head_xform = inverse(mouse_view_matrix);//goatvr_head_matrix();
 438                 Mat4 head_dir_xform = head_xform.upper3x3();
 439
 440                 glUseProgram(0);
 441                 glPushAttrib(GL_ENABLE_BIT);
 442                 glDisable(GL_LIGHTING);
 443                 glBegin(GL_LINES);
 444                 for(int i=0; i<2; i++) {
 445                         if(hand[i].valid) {
 446                                 glColor3f(i, 1 - i, i);
 447                         } else {
 448                                 glColor3f(0.5, 0.5, 0.5);
 449                         }
 450                         Vec3 v = head_xform * hand[i].pos;
 451                         Vec3 dir = head_dir_xform * rotate(Vec3(0, 0, -1), hand[i].rot) * 20.0f;
 452                         Vec3 up = head_dir_xform * rotate(Vec3(0, 1, 0), hand[i].rot) * 10.0f;
 453                         Vec3 right = head_dir_xform * rotate(Vec3(1, 0, 0), hand[i].rot) * 10.0f;
 454
 455                         glVertex3f(v.x, v.y, v.z);
 456                         glVertex3f(v.x + dir.x, v.y + dir.y, v.z + dir.z);
 457                         glVertex3f(v.x - right.x, v.y - right.y, v.z - right.z);
 458                         glVertex3f(v.x + right.x, v.y + right.y, v.z + right.z);
 459                         glVertex3f(v.x - up.x, v.y - up.y, v.z - up.z);
 460                         glVertex3f(v.x + up.x, v.y + up.y, v.z + up.z);
 461                 }
 462                 glEnd();
 463                 glPopAttrib();
 464         }
 465         */
 466
 467         if(show_walk_mesh && mscn->walk_mesh) {
 468                 glPushAttrib(GL_ENABLE_BIT);
 469                 glEnable(GL_BLEND);
 470                 glBlendFunc(GL_ONE, GL_ONE);
 471                 glDisable(GL_LIGHTING);
 472                 glEnable(GL_POLYGON_OFFSET_FILL);
 473
 474                 glUseProgram(0);
 475
 476                 glPolygonOffset(-1, 1);
 477                 glDepthMask(0);
 478
 479                 glColor3f(0.3, 0.08, 0.01);
 480                 mscn->walk_mesh->draw();
 481
 482                 glDepthMask(1);
 483
 484                 glPopAttrib();
 485         }
 486
 487         print_text(Vec2(9 * win_width / 10, 20), Vec3(1, 1, 0), "fps: %.1f", framerate);
 488         draw_ui();
 489 }
 490
 491
 492 void app_reshape(int x, int y)
 493 {
 494         glViewport(0, 0, x, y);
 495         goatvr_set_fb_size(x, y, 1.0f);
 496         debug_gui_reshape(x, y);
 497 }
 498
 499 void app_keyboard(int key, bool pressed)
 500 {
 501         unsigned int mod = app_get_modifiers();
 502
 503         if(!debug_gui_key(key, pressed, mod)) {
 504                 // the debug gui indicated that we should ignore the event
 505                 return;
 506         }
 507
 508         if(pressed) {
 509                 switch(key) {
 510                 case 27:
 511                         app_quit();
 512                         break;
 513
 514                 case '\n':
 515                 case '\r':
 516                         if(mod & MOD_ALT) {
 517                                 app_toggle_fullscreen();
 518                         }
 519                         break;
 520
 521                 case '\t':
 522                         show_debug_gui = !show_debug_gui;
 523                         show_message("debug gui %s", show_debug_gui ? "enabled" : "disabled");
 524                         break;
 525
 526                 case '`':
 527                         app_toggle_grab_mouse();
 528                         show_message("mouse %s", app_is_mouse_grabbed() ? "grabbed" : "released");
 529                         break;
 530
 531                 case 'w':
 532                         if(mod & MOD_CTRL) {
 533                                 show_walk_mesh = !show_walk_mesh;
 534                                 show_message("walk mesh: %s", show_walk_mesh ? "on" : "off");
 535                         }
 536                         break;
 537
 538                 case 'c':
 539                         if(mod & MOD_CTRL) {
 540                                 noclip = !noclip;
 541                                 show_message(noclip ? "no clip" : "clip");
 542                         }
 543                         break;
 544
 545                 case 'f':
 546                         toggle_flight();
 547                         break;
 548
 549                 case 'p':
 550                         if(mod & MOD_CTRL) {
 551                                 fb_srgb = !fb_srgb;
 552                                 show_message("gamma correction for non-sRGB framebuffers: %s\n", fb_srgb ? "off" : "on");
 553                         }
 554                         break;
 555
 556                 case '=':
 557                         walk_speed *= 1.25;
 558                         show_message("walk speed: %g", walk_speed);
 559                         break;
 560
 561                 case '-':
 562                         walk_speed *= 0.75;
 563                         show_message("walk speed: %g", walk_speed);
 564                         break;
 565
 566                 case ']':
 567                         mouse_speed *= 1.2;
 568                         show_message("mouse speed: %g", mouse_speed);
 569                         break;
 570
 571                 case '[':
 572                         mouse_speed *= 0.8;
 573                         show_message("mouse speed: %g", mouse_speed);
 574                         break;
 575
 576                 case 'b':
 577                         show_blobs = !show_blobs;
 578                         show_message("blobs: %s\n", show_blobs ? "on" : "off");
 579                         break;
 580
 581                 case ' ':
 582                         goatvr_recenter();
 583                         show_message("VR recenter\n");
 584                         break;
 585                 }
 586         }
 587
 588         if(key < 256 && !(mod & (MOD_CTRL | MOD_ALT))) {
 589                 keystate[key] = pressed;
 590         }
 591 }
 592
 593 void app_mouse_button(int bn, bool pressed, int x, int y)
 594 {
 595         if(!debug_gui_mbutton(bn, pressed, x, y)) {
 596                 // the debug GUI indicated we should ignore the event
 597                 return;
 598         }
 599
 600         prev_mx = x;
 601         prev_my = y;
 602         bnstate[bn] = pressed;
 603 }
 604
 605 static inline void mouse_look(float dx, float dy)
 606 {
 607         float scrsz = (float)win_height;
 608         avatar.body_rot += dx * 512.0 / scrsz;
 609         avatar.head_alt += dy * 512.0 / scrsz;
 610
 611         if(avatar.head_alt < -90) avatar.head_alt = -90;
 612         if(avatar.head_alt > 90) avatar.head_alt = 90;
 613 }
 614
 615 static void mouse_zoom(float dx, float dy)
 616 {
 617         cam_dist += dy * 0.1;
 618         if(cam_dist < 0.0) cam_dist = 0.0;
 619 }
 620
 621 void app_mouse_motion(int x, int y)
 622 {
 623         if(!debug_gui_mmotion(x, y)) {
 624                 // the debug GUI indicated we should ignore the event
 625                 return;
 626         }
 627
 628         int dx = x - prev_mx;
 629         int dy = y - prev_my;
 630         prev_mx = x;
 631         prev_my = y;
 632
 633         if(!dx && !dy) return;
 634
 635         if(bnstate[0]) {
 636                 mouse_look(dx, dy);
 637         }
 638         if(bnstate[2]) {
 639                 mouse_zoom(dx, dy);
 640         }
 641 }
 642
 643 void app_mouse_delta(int dx, int dy)
 644 {
 645         if(bnstate[2]) {
 646                 mouse_zoom(dx * mouse_speed, dy * mouse_speed);
 647         } else {
 648                 mouse_look(dx * mouse_speed, dy * mouse_speed);
 649         }
 650 }
 651
 652 void app_gamepad_axis(int axis, float val)
 653 {
 654         switch(axis) {
 655         case 0:
 656                 joy_move.x = val;
 657                 break;
 658         case 1:
 659                 joy_move.y = val;
 660                 break;
 661
 662         case 2:
 663                 joy_look.x = val;
 664                 break;
 665         case 3:
 666                 joy_look.y = val;
 667                 break;
 668         }
 669 }
 670
 671 void app_gamepad_button(int bn, bool pressed)
 672 {
 673         gpad_bnstate[bn] = pressed;
 674
 675         if(pressed) {
 676                 switch(bn) {
 677                 case GPAD_LSTICK:
 678                         toggle_flight();
 679                         break;
 680
 681                 case GPAD_X:
 682                         show_blobs = !show_blobs;
 683                         show_message("blobs: %s\n", show_blobs ? "on" : "off");
 684                         break;
 685
 686                 case GPAD_START:
 687                         goatvr_recenter();
 688                         show_message("VR recenter\n");
 689                         break;
 690
 691                 default:
 692                         break;
 693                 }
 694         }
 695 }
 696
 697 static void toggle_flight()
 698 {
 699         static float prev_walk_speed = -1.0;
 700         if(prev_walk_speed < 0.0) {
 701                 noclip = true;
 702                 prev_walk_speed = walk_speed;
 703                 walk_speed = 1000.0;
 704                 show_message("fly mode\n");
 705         } else {
 706                 noclip = false;
 707                 walk_speed = prev_walk_speed;
 708                 prev_walk_speed = -1.0;
 709                 show_message("walk mode\n");
 710         }
 711 }
 712
 713 static void calc_framerate()
 714 {
 715         static int ncalc;
 716         static int nframes;
 717         static long prev_upd;
 718
 719         long elapsed = time_msec - prev_upd;
 720         if(elapsed >= 1000) {
 721                 framerate = (float)nframes / (float)(elapsed * 0.001);
 722                 nframes = 1;
 723                 prev_upd = time_msec;
 724
 725                 /*if(++ncalc >= 5) {
 726                         printf("fps: %f\n", framerate);
 727                         ncalc = 0;
 728                 }*/
 729         } else {
 730                 ++nframes;
 731         }
 732 }