src/graphics/grgl1.cpp

   1 /*
   2  * Copyright (C) Volition, Inc. 1999.  All rights reserved.
   3  *
   4  * All source code herein is the property of Volition, Inc. You may not sell
   5  * or otherwise commercially exploit the source or things you created based on
   6  * the source.
   7  */
   8
   9 #include "gropengl.h"
  10 #include "grgl1.h"
  11 #include "gropenglinternal.h"
  12 #include "2d.h"
  13 #include "mouse.h"
  14 #include "pstypes.h"
  15 #include "cfile.h"
  16 #include "bmpman.h"
  17 #include "grinternal.h"
  18
  19
  20 int OGL_fog_mode = 0;
  21
  22 int GL_one_inited = 0;
  23
  24
  25 volatile int GL_activate = 0;
  26 volatile int GL_deactivate = 0;
  27
  28 static GLuint Gr_saved_screen_tex = 0;
  29
  30 static int Gr_opengl_mouse_saved = 0;
  31 static int Gr_opengl_mouse_saved_x = 0;
  32 static int Gr_opengl_mouse_saved_y = 0;
  33 static int Gr_opengl_mouse_saved_w = 0;
  34 static int Gr_opengl_mouse_saved_h = 0;
  35 static ubyte *Gr_opengl_mouse_saved_data = NULL;
  36
  37
  38 PFNGLSECONDARYCOLORPOINTERPROC vglSecondaryColorPointer = NULL;
  39
  40
  41 static gr_alpha_blend GL_current_alpha_blend = (gr_alpha_blend) -1;
  42 static gr_zbuffer_type GL_current_zbuffer_type = (gr_zbuffer_type) -1;
  43
  44 void opengl1_set_state(gr_texture_source ts, gr_alpha_blend ab, gr_zbuffer_type zt)
  45 {
  46         opengl1_set_texture_state(ts);
  47
  48         if (ab != GL_current_alpha_blend) {
  49                 switch (ab) {
  50                         case ALPHA_BLEND_NONE:                  // 1*SrcPixel + 0*DestPixel
  51                                 glBlendFunc(GL_ONE, GL_ZERO);
  52                                 break;
  53                         case ALPHA_BLEND_ADDITIVE:              // 1*SrcPixel + 1*DestPixel
  54                                 glBlendFunc(GL_ONE, GL_ONE);
  55                                 break;
  56                         case ALPHA_BLEND_ALPHA_ADDITIVE:        // Alpha*SrcPixel + 1*DestPixel
  57                                 glBlendFunc(GL_SRC_ALPHA, GL_ONE);
  58                                 break;
  59                         case ALPHA_BLEND_ALPHA_BLEND_ALPHA:     // Alpha*SrcPixel + (1-Alpha)*DestPixel
  60                                 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  61                                 break;
  62                         case ALPHA_BLEND_ALPHA_BLEND_SRC_COLOR: // Alpha*SrcPixel + (1-SrcPixel)*DestPixel
  63                                 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_COLOR);
  64                                 break;
  65                         default:
  66                                 break;
  67                 }
  68
  69                 GL_current_alpha_blend = ab;
  70         }
  71
  72         if (zt != GL_current_zbuffer_type) {
  73                 switch (zt) {
  74                         case ZBUFFER_TYPE_NONE:
  75                                 glDepthFunc(GL_ALWAYS);
  76                                 glDepthMask(GL_FALSE);
  77                                 break;
  78                         case ZBUFFER_TYPE_READ:
  79                                 glDepthFunc(GL_LESS);
  80                                 glDepthMask(GL_FALSE);
  81                                 break;
  82                         case ZBUFFER_TYPE_WRITE:
  83                                 glDepthFunc(GL_ALWAYS);
  84                                 glDepthMask(GL_TRUE);
  85                                 break;
  86                         case ZBUFFER_TYPE_FULL:
  87                                 glDepthFunc(GL_LESS);
  88                                 glDepthMask(GL_TRUE);
  89                                 break;
  90                         default:
  91                                 break;
  92                 }
  93
  94                 GL_current_zbuffer_type = zt;
  95         }
  96 }
  97
  98 void opengl1_cleanup()
  99 {
 100         if ( !GL_one_inited ) {
 101                 return;
 102         }
 103
 104         gr_opengl1_reset_clip();
 105         gr_opengl1_clear();
 106         gr_opengl1_flip();
 107
 108         gr_opengl1_free_screen(0);
 109
 110         if (Gr_opengl_mouse_saved_data) {
 111                 free(Gr_opengl_mouse_saved_data);
 112                 Gr_opengl_mouse_saved_data = NULL;
 113         }
 114
 115         opengl1_tcache_cleanup();
 116
 117         GL_one_inited = 0;
 118 }
 119
 120 static void opengl1_init_func_pointers()
 121 {
 122         gr_screen.gf_flip = gr_opengl1_flip;
 123         gr_screen.gf_set_clip = gr_opengl1_set_clip;
 124         gr_screen.gf_reset_clip = gr_opengl1_reset_clip;
 125
 126         gr_screen.gf_clear = gr_opengl1_clear;
 127
 128         gr_screen.gf_aabitmap = gr_opengl1_aabitmap;
 129         gr_screen.gf_aabitmap_ex = gr_opengl1_aabitmap_ex;
 130
 131         gr_screen.gf_rect = gr_opengl1_rect;
 132         gr_screen.gf_shade = gr_opengl1_shade;
 133         gr_screen.gf_string = gr_opengl1_string;
 134         gr_screen.gf_circle = gr_opengl1_circle;
 135
 136         gr_screen.gf_line = gr_opengl1_line;
 137         gr_screen.gf_aaline = gr_opengl1_aaline;
 138         gr_screen.gf_pixel = gr_opengl1_pixel;
 139         gr_screen.gf_scaler = gr_opengl1_scaler;
 140         gr_screen.gf_tmapper = gr_opengl1_tmapper;
 141
 142         gr_screen.gf_gradient = gr_opengl1_gradient;
 143
 144         gr_screen.gf_print_screen = gr_opengl1_print_screen;
 145
 146         gr_screen.gf_fade_in = gr_opengl1_fade_in;
 147         gr_screen.gf_fade_out = gr_opengl1_fade_out;
 148         gr_screen.gf_flash = gr_opengl1_flash;
 149
 150         gr_screen.gf_zbuffer_clear = gr_opengl1_zbuffer_clear;
 151
 152         gr_screen.gf_save_screen = gr_opengl1_save_screen;
 153         gr_screen.gf_restore_screen = gr_opengl1_restore_screen;
 154         gr_screen.gf_free_screen = gr_opengl1_free_screen;
 155
 156         gr_screen.gf_dump_frame_start = gr_opengl1_dump_frame_start;
 157         gr_screen.gf_dump_frame_stop = gr_opengl1_dump_frame_stop;
 158         gr_screen.gf_dump_frame = gr_opengl1_dump_frame;
 159
 160         gr_screen.gf_set_gamma = gr_opengl1_set_gamma;
 161
 162         gr_screen.gf_lock = gr_opengl1_lock;
 163         gr_screen.gf_unlock = gr_opengl1_unlock;
 164
 165         gr_screen.gf_fog_set = gr_opengl1_fog_set;
 166
 167         gr_screen.gf_get_region = gr_opengl1_get_region;
 168
 169         gr_screen.gf_set_cull = gr_opengl1_set_cull;
 170
 171         gr_screen.gf_cross_fade = gr_opengl1_cross_fade;
 172
 173         gr_screen.gf_preload_init = gr_opengl1_preload_init;
 174         gr_screen.gf_preload = gr_opengl1_preload;
 175
 176         gr_screen.gf_zbias = gr_opengl1_zbias;
 177
 178         gr_screen.gf_force_windowed = gr_opengl_force_windowed;
 179         gr_screen.gf_force_fullscreen = gr_opengl_force_fullscreen;
 180         gr_screen.gf_toggle_fullscreen = gr_opengl_toggle_fullscreen;
 181
 182         gr_screen.gf_set_viewport = gr_opengl1_set_viewport;
 183
 184         gr_screen.gf_activate = gr_opengl1_activate;
 185
 186         gr_screen.gf_release_texture = gr_opengl1_release_texture;
 187 }
 188
 189 void opengl1_init()
 190 {
 191         if (GL_one_inited) {
 192                 return;
 193         }
 194
 195         /*
 196           1 = use secondary color ext
 197           2 = use opengl linear fog
 198          */
 199         OGL_fog_mode = 2;
 200
 201         // only available with OpenGL 1.2+, must get ptr for Windows
 202         vglSecondaryColorPointer = (PFNGLSECONDARYCOLORPOINTERPROC)SDL_GL_GetProcAddress("glSecondaryColorPointer");
 203
 204         if (vglSecondaryColorPointer) {
 205                 OGL_fog_mode = 1;
 206         }
 207
 208         mprintf(("  Fog mode : %s\n", (OGL_fog_mode == 1) ? "secondary color" : "linear"));
 209
 210         glShadeModel(GL_SMOOTH);
 211         glEnable(GL_DITHER);
 212         glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
 213         glHint(GL_FOG_HINT, GL_NICEST);
 214
 215         glEnable(GL_DEPTH_TEST);
 216         glEnable(GL_BLEND);
 217
 218         glEnable(GL_TEXTURE_2D);
 219
 220         glDepthRange(0.0, 1.0);
 221
 222         glPixelStorei(GL_PACK_ALIGNMENT, 1);
 223         glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 224
 225         glFlush();
 226
 227         opengl1_init_func_pointers();
 228         opengl1_tcache_init();
 229
 230         gr_opengl1_clear();
 231         gr_opengl1_set_cull(1);
 232
 233         GL_one_inited = 1;
 234 }
 235
 236 void gr_opengl1_activate(int active)
 237 {
 238         if (active) {
 239                 GL_activate++;
 240
 241                 // don't grab key/mouse if cmdline says so or if we're fullscreen
 242         //      if(!Cmdline_no_grab && !(SDL_GetVideoSurface()->flags & SDL_FULLSCREEN)) {
 243         //              SDL_WM_GrabInput(SDL_GRAB_ON);
 244         //      }
 245         } else {
 246                 GL_deactivate++;
 247
 248                 // let go of mouse/keyboard
 249         //      SDL_WM_GrabInput(SDL_GRAB_OFF);
 250         }
 251 }
 252
 253 void gr_opengl1_clear()
 254 {
 255         glClearColor(gr_screen.current_clear_color.red / 255.0f,
 256                 gr_screen.current_clear_color.green / 255.0f,
 257                 gr_screen.current_clear_color.blue / 255.0f, 1.0f);
 258
 259         glClear( GL_COLOR_BUFFER_BIT );
 260 }
 261
 262 void gr_opengl1_flip()
 263 {
 264         if ( !GL_one_inited ) {
 265                 return;
 266         }
 267
 268         gr_reset_clip();
 269
 270         mouse_eval_deltas();
 271
 272         Gr_opengl_mouse_saved = 0;
 273
 274         if ( mouse_is_visible() )       {
 275                 int mx, my;
 276
 277                 gr_reset_clip();
 278                 mouse_get_pos( &mx, &my );
 279
 280                 gr_opengl1_save_mouse_area(mx,my,32,32);
 281
 282                 if (Gr_cursor == -1) {
 283 #ifndef NDEBUG
 284                         gr_set_color(255,255,255);
 285                         gr_line(mx, my, mx+7, my + 7);
 286                         gr_line(mx, my, mx+5, my );
 287                         gr_line(mx, my, mx, my+5);
 288 #endif
 289                 } else {
 290                         gr_set_bitmap(Gr_cursor);
 291                         gr_bitmap(mx, my);
 292                 }
 293          }
 294
 295 #ifndef NDEBUG
 296         GLenum error = GL_NO_ERROR;
 297
 298         do {
 299                 error = glGetError();
 300
 301                 if (error != GL_NO_ERROR) {
 302                         nprintf(("Warning", "!!DEBUG!! OpenGL Error: %d\n", error));
 303                 }
 304         } while (error != GL_NO_ERROR);
 305 #endif
 306
 307         SDL_GL_SwapWindow(GL_window);
 308
 309         opengl1_tcache_frame();
 310
 311         int cnt = GL_activate;
 312         if ( cnt )      {
 313                 GL_activate-=cnt;
 314                 opengl1_tcache_flush();
 315                 // gr_opengl_clip_cursor(1); /* mouse grab, see opengl_activate */
 316         }
 317
 318         cnt = GL_deactivate;
 319         if ( cnt )      {
 320                 GL_deactivate-=cnt;
 321                 // gr_opengl_clip_cursor(0);  /* mouse grab, see opengl_activate */
 322         }
 323 }
 324
 325 void gr_opengl1_set_clip(int x,int y,int w,int h)
 326 {
 327         // check for sanity of parameters
 328         if (x < 0)
 329                 x = 0;
 330         if (y < 0)
 331                 y = 0;
 332
 333         if (x >= gr_screen.max_w)
 334                 x = gr_screen.max_w - 1;
 335         if (y >= gr_screen.max_h)
 336                 y = gr_screen.max_h - 1;
 337
 338         if (x + w > gr_screen.max_w)
 339                 w = gr_screen.max_w - x;
 340         if (y + h > gr_screen.max_h)
 341                 h = gr_screen.max_h - y;
 342
 343         if (w > gr_screen.max_w)
 344                 w = gr_screen.max_w;
 345         if (h > gr_screen.max_h)
 346                 h = gr_screen.max_h;
 347
 348         gr_screen.offset_x = x;
 349         gr_screen.offset_y = y;
 350         gr_screen.clip_left = 0;
 351         gr_screen.clip_right = w-1;
 352         gr_screen.clip_top = 0;
 353         gr_screen.clip_bottom = h-1;
 354         gr_screen.clip_width = w;
 355         gr_screen.clip_height = h;
 356
 357         x = fl2i((x * GL_viewport_scale_w) + 0.5f) + GL_viewport_x;
 358         y = fl2i((y * GL_viewport_scale_h) + 0.5f) + GL_viewport_y;
 359         w = fl2i((w * GL_viewport_scale_w) + 0.5f);
 360         h = fl2i((h * GL_viewport_scale_h) + 0.5f);
 361
 362         glEnable(GL_SCISSOR_TEST);
 363         glScissor(x, GL_viewport_h-y-h, w, h);
 364 }
 365
 366 void gr_opengl1_reset_clip()
 367 {
 368         gr_screen.offset_x = 0;
 369         gr_screen.offset_y = 0;
 370         gr_screen.clip_left = 0;
 371         gr_screen.clip_top = 0;
 372         gr_screen.clip_right = gr_screen.max_w - 1;
 373         gr_screen.clip_bottom = gr_screen.max_h - 1;
 374         gr_screen.clip_width = gr_screen.max_w;
 375         gr_screen.clip_height = gr_screen.max_h;
 376
 377         glDisable(GL_SCISSOR_TEST);
 378 }
 379
 380 void gr_opengl1_print_screen(const char *filename)
 381 {
 382         char tmp[MAX_FILENAME_LEN];
 383         ubyte *buf = NULL;
 384
 385         SDL_strlcpy( tmp, filename, SDL_arraysize(tmp) );
 386         SDL_strlcat( tmp, NOX(".tga"), SDL_arraysize(tmp) );
 387
 388         buf = (ubyte*)malloc(GL_viewport_w * GL_viewport_h * 3);
 389
 390         if (buf == NULL) {
 391                 return;
 392         }
 393
 394         CFILE *f = cfopen(tmp, "wb", CFILE_NORMAL, CF_TYPE_ROOT);
 395
 396         if (f == NULL) {
 397                 free(buf);
 398                 return;
 399         }
 400
 401         // Write the TGA header
 402         cfwrite_ubyte( 0, f );  //      IDLength;
 403         cfwrite_ubyte( 0, f );  //      ColorMapType;
 404         cfwrite_ubyte( 2, f );  //      ImageType;              // 2 = 24bpp, uncompressed, 10=24bpp rle compressed
 405         cfwrite_ushort( 0, f ); // CMapStart;
 406         cfwrite_ushort( 0, f ); //      CMapLength;
 407         cfwrite_ubyte( 0, f );  // CMapDepth;
 408         cfwrite_ushort( 0, f ); //      XOffset;
 409         cfwrite_ushort( 0, f ); //      YOffset;
 410         cfwrite_ushort( (ushort)GL_viewport_w, f );     //      Width;
 411         cfwrite_ushort( (ushort)GL_viewport_h, f );     //      Height;
 412         cfwrite_ubyte( 24, f ); //PixelDepth;
 413         cfwrite_ubyte( 0, f );  //ImageDesc;
 414
 415         memset(buf, 0, GL_viewport_w * GL_viewport_h * 3);
 416
 417         glReadPixels(GL_viewport_x, GL_viewport_y, GL_viewport_w, GL_viewport_h, GL_BGR, GL_UNSIGNED_BYTE, buf);
 418
 419         cfwrite(buf, GL_viewport_w * GL_viewport_h * 3, 1, f);
 420
 421         cfclose(f);
 422
 423         free(buf);
 424 }
 425
 426 void gr_opengl1_fog_set(int fog_mode, int r, int g, int b, float fog_near, float fog_far)
 427 {
 428         SDL_assert((r >= 0) && (r < 256));
 429         SDL_assert((g >= 0) && (g < 256));
 430         SDL_assert((b >= 0) && (b < 256));
 431
 432         if (fog_mode == GR_FOGMODE_NONE) {
 433                 if (gr_screen.current_fog_mode != fog_mode) {
 434                         glDisable(GL_FOG);
 435
 436                         if (OGL_fog_mode == 1) {
 437                                 glDisable(GL_COLOR_SUM);
 438                         }
 439                 }
 440
 441                 gr_screen.current_fog_mode = fog_mode;
 442
 443                 return;
 444         }
 445
 446         if (gr_screen.current_fog_mode != fog_mode) {
 447                 glEnable(GL_FOG);
 448
 449                 if (OGL_fog_mode == 1) {
 450                         glEnable(GL_COLOR_SUM);
 451                 } else if (OGL_fog_mode == 2) {
 452                         glFogi(GL_FOG_MODE, GL_LINEAR);
 453                 }
 454
 455                 gr_screen.current_fog_mode = fog_mode;
 456         }
 457
 458         if ( (gr_screen.current_fog_color.red != r) ||
 459                         (gr_screen.current_fog_color.green != g) ||
 460                         (gr_screen.current_fog_color.blue != b) ) {
 461                 GLfloat fc[4];
 462
 463                 gr_init_color( &gr_screen.current_fog_color, r, g, b );
 464
 465                 fc[0] = r / 255.0f;
 466                 fc[1] = g / 255.0f;
 467                 fc[2] = b / 255.0f;
 468                 fc[3] = 1.0f;
 469
 470                 glFogfv(GL_FOG_COLOR, fc);
 471         }
 472
 473         if( (fog_near >= 0.0f) && (fog_far >= 0.0f) &&
 474                         ((fog_near != gr_screen.fog_near) ||
 475                         (fog_far != gr_screen.fog_far)) ) {
 476                 gr_screen.fog_near = fog_near;
 477                 gr_screen.fog_far = fog_far;
 478
 479                 if (OGL_fog_mode == 2) {
 480                         glFogf(GL_FOG_START, fog_near);
 481                         glFogf(GL_FOG_END, fog_far);
 482                 }
 483         }
 484 }
 485
 486 void gr_opengl1_set_cull(int cull)
 487 {
 488         if (cull) {
 489                 glEnable (GL_CULL_FACE);
 490                 glFrontFace (GL_CCW);
 491         } else {
 492                 glDisable (GL_CULL_FACE);
 493         }
 494 }
 495
 496 void gr_opengl1_zbuffer_clear(int mode)
 497 {
 498         if (mode) {
 499                 Gr_zbuffering = 1;
 500                 Gr_zbuffering_mode = GR_ZBUFF_FULL;
 501                 Gr_global_zbuffering = 1;
 502
 503                 opengl1_set_state( TEXTURE_SOURCE_NONE, ALPHA_BLEND_NONE, ZBUFFER_TYPE_FULL );
 504                 glClear ( GL_DEPTH_BUFFER_BIT );
 505         } else {
 506                 Gr_zbuffering = 0;
 507                 Gr_zbuffering_mode = GR_ZBUFF_NONE;
 508                 Gr_global_zbuffering = 0;
 509         }
 510 }
 511
 512 void gr_opengl1_fade_in(int instantaneous)
 513 {
 514         // Empty - DDOI
 515 }
 516
 517 void gr_opengl1_fade_out(int instantaneous)
 518 {
 519         // Empty - DDOI
 520 }
 521
 522 void gr_opengl1_get_region(int front, int w, int h, ubyte *data)
 523 {
 524         if (front) {
 525                 glReadBuffer(GL_FRONT);
 526         } else {
 527                 glReadBuffer(GL_BACK);
 528         }
 529
 530         opengl1_set_state(TEXTURE_SOURCE_NO_FILTERING, ALPHA_BLEND_NONE, ZBUFFER_TYPE_NONE);
 531
 532         glPixelStorei(GL_UNPACK_ROW_LENGTH, GL_viewport_w);
 533
 534         int x = GL_viewport_x;
 535         int y = (GL_viewport_y+GL_viewport_h)-h-1;
 536
 537         GLenum pxtype = GL_UNSIGNED_SHORT_1_5_5_5_REV;
 538
 539         if (gr_screen.bytes_per_pixel == 4) {
 540                 pxtype = GL_UNSIGNED_BYTE;
 541         }
 542
 543         glReadPixels(x, y, w, h, GL_BGRA, pxtype, data);
 544
 545         glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 546 }
 547
 548 void gr_opengl1_save_mouse_area(int x, int y, int w, int h)
 549 {
 550         int x1, y1, x2, y2;
 551
 552         if (Gr_saved_screen_tex) {
 553                 // already saved, don't need it again
 554                 return;
 555         }
 556
 557         w = fl2i((w * GL_viewport_scale_w) + 0.5f);
 558         h = fl2i((h * GL_viewport_scale_h) + 0.5f);
 559
 560         x1 = x;
 561         y1 = y;
 562         x2 = x+w-1;
 563         y2 = y+h-1;
 564
 565         CAP(x1, 0, GL_viewport_w);
 566         CAP(x2, 0, GL_viewport_w);
 567         CAP(y1, 0, GL_viewport_h);
 568         CAP(y2, 0, GL_viewport_h);
 569
 570         Gr_opengl_mouse_saved_x = x1;
 571         Gr_opengl_mouse_saved_y = y1;
 572         Gr_opengl_mouse_saved_w = x2 - x1 + 1;
 573         Gr_opengl_mouse_saved_h = y2 - y1 + 1;
 574
 575         if ( (Gr_opengl_mouse_saved_w < 1) || (Gr_opengl_mouse_saved_h < 1) ) {
 576                 return;
 577         }
 578
 579         if (Gr_opengl_mouse_saved_data == NULL) {
 580                 Gr_opengl_mouse_saved_data = (ubyte*)malloc(w * h * 3);
 581
 582                 if ( !Gr_opengl_mouse_saved_data ) {
 583                         return;
 584                 }
 585         }
 586
 587         x1 = GL_viewport_x+Gr_opengl_mouse_saved_x;
 588         y1 = (GL_viewport_y+GL_viewport_h)-Gr_opengl_mouse_saved_y-Gr_opengl_mouse_saved_h;
 589
 590         glReadBuffer(GL_BACK);
 591
 592         glReadPixels(x1, y1, Gr_opengl_mouse_saved_w, Gr_opengl_mouse_saved_h,
 593                         GL_BGR, GL_UNSIGNED_BYTE, Gr_opengl_mouse_saved_data);
 594
 595         Gr_opengl_mouse_saved = 1;
 596 }
 597
 598 int gr_opengl1_save_screen()
 599 {
 600         gr_reset_clip();
 601
 602         if (Gr_saved_screen_tex) {
 603                 mprintf(( "Screen already saved!\n" ));
 604                 return -1;
 605         }
 606
 607         glGenTextures(1, &Gr_saved_screen_tex);
 608
 609         if ( !Gr_saved_screen_tex ) {
 610                 mprintf(( "Couldn't create texture for saved screen!\n" ));
 611                 return -1;
 612         }
 613
 614         glBindTexture(GL_TEXTURE_2D, Gr_saved_screen_tex);
 615
 616         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 617         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 618         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 619         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 620         glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 621
 622         glReadBuffer(GL_FRONT);
 623
 624         glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, GL_viewport_x, GL_viewport_y,
 625                         GL_viewport_w, GL_viewport_h, 0);
 626
 627         if (Gr_opengl_mouse_saved) {
 628                 int x = Gr_opengl_mouse_saved_x;
 629                 int y = GL_viewport_h-Gr_opengl_mouse_saved_y-Gr_opengl_mouse_saved_h;
 630
 631                 glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, Gr_opengl_mouse_saved_w,
 632                                 Gr_opengl_mouse_saved_h, GL_BGR, GL_UNSIGNED_BYTE,
 633                                 Gr_opengl_mouse_saved_data);
 634         }
 635
 636         glBindTexture(GL_TEXTURE_2D, 0);
 637
 638         return 0;
 639 }
 640
 641 void gr_opengl1_restore_screen(int)
 642 {
 643         gr_reset_clip();
 644
 645         if ( !Gr_saved_screen_tex ) {
 646                 gr_clear();
 647                 return;
 648         }
 649
 650         int x = 0;
 651         int y = 0;
 652         int w = fl2i(GL_viewport_w / GL_viewport_scale_w + 0.5f);
 653         int h = fl2i(GL_viewport_h / GL_viewport_scale_h + 0.5f);
 654
 655         const int tex_coord[] = { 0, 1, 0, 0, 1, 1, 1, 0 };     // y-flipped
 656         const int ver_coord[] = { x, y, x, h, w, y, w, h };
 657
 658         glColor4ub(255, 255, 255, 255);
 659
 660         glBindTexture(GL_TEXTURE_2D, Gr_saved_screen_tex);
 661
 662         opengl1_set_state(TEXTURE_SOURCE_NO_FILTERING, ALPHA_BLEND_NONE, ZBUFFER_TYPE_NONE);
 663
 664         glEnableClientState(GL_TEXTURE_COORD_ARRAY);
 665         glEnableClientState(GL_VERTEX_ARRAY);
 666
 667         glTexCoordPointer(2, GL_INT, 0, &tex_coord);
 668         glVertexPointer(2, GL_INT, 0, &ver_coord);
 669
 670         glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 671
 672         glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 673         glDisableClientState(GL_VERTEX_ARRAY);
 674
 675         glBindTexture(GL_TEXTURE_2D, 0);
 676 }
 677
 678 void gr_opengl1_free_screen(int)
 679 {
 680         if (Gr_saved_screen_tex) {
 681                 glDeleteTextures(1, &Gr_saved_screen_tex);
 682                 Gr_saved_screen_tex = 0;
 683         }
 684 }
 685
 686 void gr_opengl1_dump_frame_start(int first_frame, int frames_between_dumps)
 687 {
 688         STUB_FUNCTION;
 689 }
 690
 691 void gr_opengl1_dump_frame_stop()
 692 {
 693         STUB_FUNCTION;
 694 }
 695
 696 void gr_opengl1_dump_frame()
 697 {
 698         STUB_FUNCTION;
 699 }
 700
 701 uint gr_opengl1_lock()
 702 {
 703         return 1;
 704 }
 705
 706 void gr_opengl1_unlock()
 707 {
 708 }
 709
 710 void gr_opengl1_zbias(int bias)
 711 {
 712         if (bias) {
 713                 glEnable(GL_POLYGON_OFFSET_FILL);
 714                 glPolygonOffset(0.0f, GLfloat(-bias));
 715         } else {
 716                 glDisable(GL_POLYGON_OFFSET_FILL);
 717         }
 718 }
 719
 720 void gr_opengl1_set_viewport(int width, int height)
 721 {
 722         int w, h, x, y;
 723
 724         float ratio = gr_screen.max_w / i2fl(gr_screen.max_h);
 725
 726         w = width;
 727         h = fl2i((width / ratio) + 0.5f);
 728
 729         if (h > height) {
 730                 h = height;
 731                 w = fl2i((height * ratio) + 0.5f);
 732         }
 733
 734         x = (width - w) / 2;
 735         y = (height - h) / 2;
 736
 737         GL_viewport_x = x;
 738         GL_viewport_y = y;
 739         GL_viewport_w = w;
 740         GL_viewport_h = h;
 741         GL_viewport_scale_w = w / i2fl(gr_screen.max_w);
 742         GL_viewport_scale_h = h / i2fl(gr_screen.max_h);
 743
 744         glViewport(GL_viewport_x, GL_viewport_y, GL_viewport_w, GL_viewport_h);
 745
 746         glMatrixMode(GL_PROJECTION);
 747         glLoadIdentity();
 748         glOrtho(0, GL_viewport_w, GL_viewport_h, 0, 0.0, 1.0);
 749         glMatrixMode(GL_MODELVIEW);
 750         glLoadIdentity();
 751         glScalef(GL_viewport_scale_w, GL_viewport_scale_h, 1.0f);
 752
 753         // free mouse cursor storage, since the size might have changed
 754         if (Gr_opengl_mouse_saved_data) {
 755                 free(Gr_opengl_mouse_saved_data);
 756                 Gr_opengl_mouse_saved_data = NULL;
 757         }
 758
 759         // clear screen once to fix issues with edges on non-4:3
 760         gr_opengl1_clear();
 761 }