texmap/ntmap.c

   1 /*
   2 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
   3 SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
   4 END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
   5 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
   6 IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
   7 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
   8 FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
   9 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
  10 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
  11 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
  12 */
  13 /*
  14  * $Source: /cvs/cvsroot/d2x/texmap/ntmap.c,v $
  15  * $Revision: 1.6 $
  16  * $Author: bradleyb $
  17  * $Date: 2002-02-23 22:24:10 $
  18  *
  19  * Start of conversion to new texture mapper.
  20  *
  21  * $Log: not supported by cvs2svn $
  22  * Revision 1.5  2001/10/25 09:12:16  bradleyb
  23  * Completed tmap selection code.
  24  *
  25  * Revision 1.4  2001/10/25 02:22:46  bradleyb
  26  * adding support for runtime selection of tmap funcs
  27  *
  28  * Revision 1.3  2001/01/31 15:18:04  bradleyb
  29  * Makefile and conf.h fixes
  30  *
  31  * Revision 1.2  2001/01/31 14:04:46  bradleyb
  32  * Fix compiler warnings
  33  *
  34  * Revision 1.1.1.1  2001/01/19 03:30:16  bradleyb
  35  * Import of d2x-0.0.8
  36  *
  37  * Revision 1.4  1999/10/18 00:31:55  donut
  38  * allow FP_TMAP to be used without NO_ASM
  39  *
  40  * Revision 1.3  1999/08/05 22:53:41  sekmu
  41  *
  42  * D3D patch(es) from ADB
  43  *
  44  * Revision 1.2  1999/07/07 21:31:09  donut
  45  * removed unused vars from ntmap_scanline_lighted and slightly optomized it
  46  *
  47  * Revision 1.1.1.1  1999/06/14 22:14:06  donut
  48  * Import of d1x 1.37 source.
  49  *
  50  * Revision 1.52  1995/03/14  15:13:06  john
  51  * Increased MAX_Y_Pointers to 480.
  52  *
  53  * Revision 1.51  1995/02/23  14:25:09  john
  54  * Added editor tmap.
  55  *
  56  * Revision 1.50  1995/02/20  18:22:58  john
  57  * Put all the externs in the assembly modules into tmap_inc.asm.
  58  * Also, moved all the C versions of the inner loops into a new module,
  59  * scanline.c.
  60  *
  61  * Revision 1.49  1995/02/20  17:09:11  john
  62  * Added code so that you can build the tmapper with no assembly!
  63  *
  64  * Revision 1.48  1995/01/06  11:11:30  mike
  65  * even when not in editor, have 400 lines in texture map scanline table.
  66  *
  67  * Revision 1.47  1994/12/15  16:43:25  matt
  68  * Took out code only needed by editor
  69  *
  70  * Revision 1.46  1994/12/09  22:35:37  mike
  71  * fix bug in before call to asm_tmap_scanline_per causing write of pixel onto past right border onto left.
  72  *
  73  * Revision 1.45  1994/12/06  16:31:06  mike
  74  * fix bug in asm_tmap_scanline_matt interface.
  75  *
  76  * Revision 1.44  1994/12/04  20:37:18  mike
  77  * *** empty log message ***
  78  *
  79  * Revision 1.43  1994/12/02  23:30:04  mike
  80  * optimizations.
  81  *
  82  * Revision 1.42  1994/11/30  00:57:43  mike
  83  * optimizations.
  84  *
  85  * Revision 1.41  1994/11/28  13:34:27  mike
  86  * optimizations.
  87  *
  88  * Revision 1.40  1994/11/28  01:30:01  mike
  89  * kill warning.
  90  *
  91  * Revision 1.39  1994/11/28  01:28:59  mike
  92  * optimizations.
  93  *
  94  * Revision 1.38  1994/11/21  14:08:07  john
  95  * Took out all multiple instead of divide code.
  96  *
  97  * Revision 1.37  1994/11/19  15:21:52  mike
  98  * rip out unused code.
  99  *
 100  * Revision 1.36  1994/11/14  11:42:51  mike
 101  * optimization.
 102  *
 103  * Revision 1.35  1994/11/12  16:41:36  mike
 104  * *** empty log message ***
 105  *
 106  * Revision 1.34  1994/11/10  21:28:41  mike
 107  * remove call to init_interface_vars_to_assembler.
 108  *
 109  * Revision 1.33  1994/11/10  11:08:59  mike
 110  * detail level stuff.
 111  *
 112  * Revision 1.32  1994/11/09  22:55:52  matt
 113  * Added variable Current_seg_depth for detail level optimization
 114  *
 115  * Revision 1.31  1994/11/09  19:57:31  john
 116  * Added texture rle caching.
 117  *
 118  * Revision 1.30  1994/11/09  19:54:48  mike
 119  * Call flat shader if Tmap_flat_flag set.
 120  *
 121  * Revision 1.29  1994/11/02  21:33:31  john
 122  * Added Burger Bill's optimization, ie.. 2 muls per 8 pixels.
 123  *
 124  * Revision 1.28  1994/11/02  11:32:16  john
 125  * Added code for c callable inner loop and code to
 126  * test dividing out z0.
 127  *
 128  * Revision 1.27  1994/10/28  20:54:32  matt
 129  * Added error checking
 130  *
 131  * Revision 1.26  1994/10/25  11:20:20  mike
 132  * fix bug in lighting overflow checking for one scanline tall linear texture maps.
 133  *
 134  * Revision 1.25  1994/08/03  15:40:33  mike
 135  * Prevent divide overflows, decrease occurrence of precision-caused glitches.
 136  *
 137  * Revision 1.24  1994/07/27  09:31:16  mike
 138  * Fix concave texture map problem, decrease occurrence of unimportant int 3.
 139  *
 140  * Revision 1.23  1994/06/17  12:23:31  mike
 141  * Support non-lighted texture maps.
 142  *
 143  * Revision 1.22  1994/06/11  08:10:24  mike
 144  * Fix mysterious hang bug, lighting value was out of range.
 145  *
 146  * Revision 1.21  1994/06/09  16:10:16  mike
 147  * Change SC2000 from constant to variable.
 148  *
 149  */
 150
 151 #ifdef HAVE_CONFIG_H
 152 #include <conf.h>
 153 #endif
 154
 155 #ifdef RCS
 156 static char rcsid[] = "$Id: ntmap.c,v 1.6 2002-02-23 22:24:10 bradleyb Exp $";
 157 #endif
 158
 159 #define VESA 0
 160 #define NUM_TMAPS 16
 161
 162 #define HEADLIGHT_LIGHTING 0
 163
 164 #define WIREFRAME 0
 165 #define PERSPECTIVE 1
 166
 167 #include "pstypes.h"
 168 #include "fix.h"
 169 #include "vecmat.h"
 170 #include "gr.h"
 171 #include "3d.h"
 172 #include "error.h"
 173
 174 #include "texmap.h"
 175 #include "texmapl.h"
 176 #include "rle.h"
 177 #include "scanline.h"
 178
 179 //#include "../main/textures.h"
 180
 181 #ifdef EDITOR
 182 #define EDITOR_TMAP 1       //if in, include extra stuff
 183 #endif
 184
 185 #define F15_5 (F1_0*15 + F0_5)
 186
 187 // Temporary texture map, interface from Matt's 3d system to Mike's texture mapper.
 188 g3ds_tmap Tmap1;
 189
 190 grs_bitmap Texmap_ptrs[NUM_TMAPS];
 191 grs_bitmap Texmap4_ptrs[NUM_TMAPS];
 192
 193 fix Range_max=0; // debug, kill me
 194
 195 int     Interpolation_method=0; // 0 = choose best method
 196 int     Lighting_on=1;                  // initialize to no lighting
 197 int     Tmap_flat_flag = 0;             //      1 = render texture maps as flat shaded polygons.
 198 int     Current_seg_depth;              // HACK INTERFACE: how far away the current segment (& thus texture) is
 199 int     Max_perspective_depth;
 200 int     Max_linear_depth;
 201 int     Max_flat_depth;
 202
 203 extern int Window_clip_left, Window_clip_bot, Window_clip_right, Window_clip_top;
 204
 205 // These variables are the interface to assembler.  They get set for each texture map, which is a real waste of time.
 206 //      They should be set only when they change, which is generally when the window bounds change.  And, even still, it's
 207 //      a pretty bad interface.
 208 int     bytes_per_row=-1;
 209 unsigned char *write_buffer;
 210 int     window_left;
 211 int     window_right;
 212 int     window_top;
 213 int     window_bottom;
 214 int     window_width;
 215 int     window_height;
 216
 217 #define MAX_Y_POINTERS  1024
 218
 219 int     y_pointers[MAX_Y_POINTERS];
 220
 221 fix fix_recip[FIX_RECIP_TABLE_SIZE];
 222
 223 int     Lighting_enabled;
 224 int     Fix_recip_table_computed=0;
 225
 226 fix fx_l, fx_u, fx_v, fx_z, fx_du_dx, fx_dv_dx, fx_dz_dx, fx_dl_dx;
 227 int fx_xleft, fx_xright, fx_y;
 228 unsigned char * pixptr;
 229 int per2_flag = 0;
 230 int Transparency_on = 0;
 231 int dither_intensity_lighting = 0;
 232
 233 ubyte * tmap_flat_cthru_table;
 234 ubyte tmap_flat_color;
 235 ubyte tmap_flat_shade_value;
 236
 237
 238
 239 // -------------------------------------------------------------------------------------
 240 void init_fix_recip_table(void)
 241 {
 242         int     i;
 243
 244         fix_recip[0] = F1_0;
 245
 246         for (i=1; i<FIX_RECIP_TABLE_SIZE; i++)
 247                 fix_recip[i] = F1_0/i;
 248
 249         Fix_recip_table_computed = 1;
 250 }
 251
 252 // -------------------------------------------------------------------------------------
 253 //      Initialize interface variables to assembler.
 254 //      These things used to be constants.  This routine is now (10/6/93) getting called for
 255 //      every texture map.  It should get called whenever the window changes, or, preferably,
 256 //      not at all.  I'm pretty sure these variables are only being used for range checking.
 257 void init_interface_vars_to_assembler(void)
 258 {
 259         grs_bitmap      *bp;
 260
 261         bp = &grd_curcanv->cv_bitmap;
 262
 263         Assert(bp!=NULL);
 264         Assert(bp->bm_data!=NULL);
 265         Assert(bp->bm_h <= MAX_Y_POINTERS);
 266
 267         //      If bytes_per_row has changed, create new table of pointers.
 268         if (bytes_per_row != (int) bp->bm_rowsize) {
 269                 int     y_val, i;
 270
 271                 bytes_per_row = (int) bp->bm_rowsize;
 272
 273                 y_val = 0;
 274                 for (i=0; i<MAX_Y_POINTERS; i++) {
 275                         y_pointers[i] = y_val;
 276                         y_val += bytes_per_row;
 277                 }
 278         }
 279
 280         write_buffer = (unsigned char *) bp->bm_data;
 281
 282         window_left = 0;
 283         window_right = (int) bp->bm_w-1;
 284         window_top = 0;
 285         window_bottom = (int) bp->bm_h-1;
 286
 287         Window_clip_left = window_left;
 288         Window_clip_right = window_right;
 289         Window_clip_top = window_top;
 290         Window_clip_bot = window_bottom;
 291
 292         window_width = bp->bm_w;
 293         window_height = bp->bm_h;
 294
 295         if (!Fix_recip_table_computed)
 296                 init_fix_recip_table();
 297 }
 298
 299 // -------------------------------------------------------------------------------------
 300 //                             VARIABLES
 301 extern g3ds_tmap Tmap1;
 302
 303 // -------------------------------------------------------------------------------------
 304 //      Returns number preceding val modulo modulus.
 305 //      prevmod(3,4) = 2
 306 //      prevmod(0,4) = 3
 307 int prevmod(int val,int modulus)
 308 {
 309         if (val > 0)
 310                 return val-1;
 311         else
 312                 return modulus-1;
 313 //      return (val + modulus - 1) % modulus;
 314 }
 315
 316
 317 //      Returns number succeeding val modulo modulus.
 318 //      succmod(3,4) = 0
 319 //      succmod(0,4) = 1
 320 int succmod(int val,int modulus)
 321 {
 322         if (val < modulus-1)
 323                 return val+1;
 324         else
 325                 return 0;
 326
 327 //      return (val + 1) % modulus;
 328 }
 329
 330 // -------------------------------------------------------------------------------------
 331 //      Select topmost vertex (minimum y coordinate) and bottommost (maximum y coordinate) in
 332 //      texture map.  If either is part of a horizontal edge, then select leftmost vertex for
 333 //      top, rightmost vertex for bottom.
 334 //      Important: Vertex is selected with integer precision.  So, if there are vertices at
 335 //      (0.0,0.7) and (0.5,0.3), the first vertex is selected, because they y coordinates are
 336 //      considered the same, so the smaller x is favored.
 337 //      Parameters:
 338 //              nv              number of vertices
 339 //              v3d     pointer to 3d vertices containing u,v,x2d,y2d coordinates
 340 //      Results in:
 341 //              *min_y_ind
 342 //              *max_y_ind
 343 // -------------------------------------------------------------------------------------
 344 void compute_y_bounds(g3ds_tmap *t, int *vlt, int *vlb, int *vrt, int *vrb,int *bottom_y_ind)
 345 {
 346         int     i;
 347         int     min_y,max_y;
 348         int     min_y_ind;
 349         int     original_vrt;
 350         fix     min_x;
 351
 352         // Scan all vertices, set min_y_ind to vertex with smallest y coordinate.
 353         min_y = f2i(t->verts[0].y2d);
 354         max_y = min_y;
 355         min_y_ind = 0;
 356         min_x = f2i(t->verts[0].x2d);
 357         *bottom_y_ind = 0;
 358
 359         for (i=1; i<t->nv; i++) {
 360                 if (f2i(t->verts[i].y2d) < min_y) {
 361                         min_y = f2i(t->verts[i].y2d);
 362                         min_y_ind = i;
 363                         min_x = f2i(t->verts[i].x2d);
 364                 } else if (f2i(t->verts[i].y2d) == min_y) {
 365                         if (f2i(t->verts[i].x2d) < min_x) {
 366                                 min_y_ind = i;
 367                                 min_x = f2i(t->verts[i].x2d);
 368                         }
 369                 }
 370                 if (f2i(t->verts[i].y2d) > max_y) {
 371                         max_y = f2i(t->verts[i].y2d);
 372                         *bottom_y_ind = i;
 373                 }
 374         }
 375
 376 //--removed mk, 11/27/94--      //      Check for a non-upright-hourglass polygon and fix, if necessary, by bashing a y coordinate.
 377 //--removed mk, 11/27/94--      //      min_y_ind = index of minimum y coordinate, *bottom_y_ind = index of maximum y coordinate
 378 //--removed mk, 11/27/94--{
 379 //--removed mk, 11/27/94--      int     max_temp, min_temp;
 380 //--removed mk, 11/27/94--
 381 //--removed mk, 11/27/94--      max_temp = *bottom_y_ind;
 382 //--removed mk, 11/27/94--      if (*bottom_y_ind < min_y_ind)
 383 //--removed mk, 11/27/94--              max_temp += t->nv;
 384 //--removed mk, 11/27/94--
 385 //--removed mk, 11/27/94--      for (i=min_y_ind; i<max_temp; i++) {
 386 //--removed mk, 11/27/94--              if (f2i(t->verts[i%t->nv].y2d) > f2i(t->verts[(i+1)%t->nv].y2d)) {
 387 //--removed mk, 11/27/94--                      Int3();
 388 //--removed mk, 11/27/94--                      t->verts[(i+1)%t->nv].y2d = t->verts[i%t->nv].y2d;
 389 //--removed mk, 11/27/94--              }
 390 //--removed mk, 11/27/94--      }
 391 //--removed mk, 11/27/94--
 392 //--removed mk, 11/27/94--      min_temp = min_y_ind;
 393 //--removed mk, 11/27/94--      if (min_y_ind < *bottom_y_ind)
 394 //--removed mk, 11/27/94--              min_temp += t->nv;
 395 //--removed mk, 11/27/94--
 396 //--removed mk, 11/27/94--      for (i=*bottom_y_ind; i<min_temp; i++) {
 397 //--removed mk, 11/27/94--              if (f2i(t->verts[i%t->nv].y2d) < f2i(t->verts[(i+1)%t->nv].y2d)) {
 398 //--removed mk, 11/27/94--                      Int3();
 399 //--removed mk, 11/27/94--                      t->verts[(i+1)%t->nv].y2d = t->verts[i%t->nv].y2d;
 400 //--removed mk, 11/27/94--              }
 401 //--removed mk, 11/27/94--      }
 402 //--removed mk, 11/27/94--}
 403
 404         // Set "vertex left top", etc. based on vertex with topmost y coordinate
 405         *vlt = min_y_ind;
 406         *vrt = *vlt;
 407         *vlb = prevmod(*vlt,t->nv);
 408         *vrb = succmod(*vrt,t->nv);
 409
 410         // If right edge is horizontal, then advance along polygon bound until it no longer is or until all
 411         // vertices have been examined.
 412         // (Left edge cannot be horizontal, because *vlt is set to leftmost point with highest y coordinate.)
 413
 414         original_vrt = *vrt;
 415
 416         while (f2i(t->verts[*vrt].y2d) == f2i(t->verts[*vrb].y2d)) {
 417                 if (succmod(*vrt,t->nv) == original_vrt) {
 418                         break;
 419                 }
 420                 *vrt = succmod(*vrt,t->nv);
 421                 *vrb = succmod(*vrt,t->nv);
 422         }
 423 }
 424
 425 // -------------------------------------------------------------------------------------
 426 //      Returns dx/dy given two vertices.
 427 //      If dy == 0, returns 0.0
 428 // -------------------------------------------------------------------------------------
 429 //--fix compute_dx_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex)
 430 //--{
 431 //--    int     dy;
 432 //--
 433 //--    // compute delta x with respect to y for any edge
 434 //--    dy = f2i(t->verts[bottom_vertex].y2d - t->verts[top_vertex].y2d) + 1;
 435 //--    if (dy)
 436 //--            return (t->verts[bottom_vertex].x2d - t->verts[top_vertex].x2d) / dy;
 437 //--    else
 438 //--            return 0;
 439 //--
 440 //--}
 441
 442 fix compute_du_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 443 {
 444         return fixmul(t->verts[bottom_vertex].u - t->verts[top_vertex].u, recip_dy);
 445 }
 446
 447
 448 fix compute_dv_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 449 {
 450         return fixmul(t->verts[bottom_vertex].v - t->verts[top_vertex].v, recip_dy);
 451 }
 452
 453 fix compute_dl_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 454 {
 455         return fixmul(t->verts[bottom_vertex].l - t->verts[top_vertex].l, recip_dy);
 456
 457 }
 458
 459 fix compute_dx_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 460 {
 461         return fixmul(t->verts[bottom_vertex].x2d - t->verts[top_vertex].x2d, recip_dy);
 462 }
 463
 464 fix compute_du_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 465 {
 466         return fixmul(fixmul(t->verts[bottom_vertex].u,t->verts[bottom_vertex].z) - fixmul(t->verts[top_vertex].u,t->verts[top_vertex].z), recip_dy);
 467 }
 468
 469
 470 fix compute_dv_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 471 {
 472         return fixmul(fixmul(t->verts[bottom_vertex].v,t->verts[bottom_vertex].z) - fixmul(t->verts[top_vertex].v,t->verts[top_vertex].z), recip_dy);
 473
 474 }
 475
 476 fix compute_dz_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 477 {
 478         return fixmul(t->verts[bottom_vertex].z - t->verts[top_vertex].z, recip_dy);
 479
 480 }
 481 int Skip_short_flag=0;
 482
 483 // -------------------------------------------------------------------------------------
 484 //      Texture map current scanline in perspective.
 485 // -------------------------------------------------------------------------------------
 486 void ntmap_scanline_lighted(grs_bitmap *srcb, int y, fix xleft, fix xright, fix uleft, fix uright, fix vleft, fix vright, fix zleft, fix zright, fix lleft, fix lright)
 487 {
 488         fix     dx,recip_dx;
 489
 490         fx_xright = f2i(xright);
 491         //edited 06/27/99 Matt Mueller - moved these tests up from within the switch so as not to do a bunch of needless calculations when we are just gonna return anyway.  Slight fps boost?
 492         if (fx_xright < Window_clip_left)
 493                 return;
 494         fx_xleft = f2i(xleft);
 495         if (fx_xleft > Window_clip_right)
 496                 return;
 497         //end edit -MM
 498
 499         dx = fx_xright - fx_xleft;
 500         if ((dx < 0) || (xright < 0) || (xleft > xright))               // the (xleft > xright) term is not redundant with (dx < 0) because dx is computed using integers
 501                 return;
 502
 503         // setup to call assembler scanline renderer
 504         if (dx < FIX_RECIP_TABLE_SIZE)
 505                 recip_dx = fix_recip[dx];
 506         else
 507                 recip_dx = F1_0/dx;
 508
 509         fx_u = uleft;
 510         fx_v = vleft;
 511         fx_z = zleft;
 512
 513         fx_du_dx = fixmul(uright - uleft,recip_dx);
 514         fx_dv_dx = fixmul(vright - vleft,recip_dx);
 515         fx_dz_dx = fixmul(zright - zleft,recip_dx);
 516         fx_y = y;
 517         pixptr = srcb->bm_data;
 518
 519         switch (Lighting_enabled) {
 520                 case 0:
 521                         //added 05/17/99 Matt Mueller - prevent writing before the buffer
 522             if ((fx_y == 0) && (fx_xleft < 0))
 523                                 fx_xleft = 0;
 524                         //end addition -MM
 525                         if (fx_xright > Window_clip_right)
 526                                 fx_xright = Window_clip_right;
 527
 528                         cur_tmap_scanline_per();
 529                         break;
 530                 case 1: {
 531                         fix     mul_thing;
 532
 533                         if (lleft < 0) lleft = 0;
 534                         if (lright < 0) lright = 0;
 535                         if (lleft > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2)) lleft = (NUM_LIGHTING_LEVELS*F1_0-F1_0/2);
 536                         if (lright > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2)) lright = (NUM_LIGHTING_LEVELS*F1_0-F1_0/2);
 537
 538                         fx_l = lleft;
 539                         fx_dl_dx = fixmul(lright - lleft,recip_dx);
 540
 541                         //      This is a pretty ugly hack to prevent lighting overflows.
 542                         mul_thing = dx * fx_dl_dx;
 543                         if (lleft + mul_thing < 0)
 544                                 fx_dl_dx += 12;
 545                         else if (lleft + mul_thing > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2))
 546                                 fx_dl_dx -= 12;
 547
 548                         //added 05/17/99 Matt Mueller - prevent writing before the buffer
 549             if ((fx_y == 0) && (fx_xleft < 0))
 550                                 fx_xleft = 0;
 551                         //end addition -MM
 552                         if (fx_xright > Window_clip_right)
 553                                 fx_xright = Window_clip_right;
 554
 555                         cur_tmap_scanline_per();
 556                         break;
 557                 }
 558                 case 2:
 559 #ifdef EDITOR_TMAP
 560                         fx_xright = f2i(xright);
 561                         fx_xleft = f2i(xleft);
 562
 563                         tmap_flat_color = 1;
 564                         cur_tmap_scanline_flat();
 565 #else
 566                         Int3(); //      Illegal, called an editor only routine!
 567 #endif
 568                         break;
 569         }
 570
 571 }
 572
 573 int Do_vertical_scan=0;
 574
 575 int     Break_on_flat=0;
 576
 577 // -------------------------------------------------------------------------------------
 578 //      Render a texture map with lighting using perspective interpolation in inner and outer loops.
 579 // -------------------------------------------------------------------------------------
 580 void ntexture_map_lighted(grs_bitmap *srcb, g3ds_tmap *t)
 581 {
 582         int     vlt,vrt,vlb,vrb;        // vertex left top, vertex right top, vertex left bottom, vertex right bottom
 583         int     topy,boty,y, dy;
 584         fix     dx_dy_left,dx_dy_right;
 585         fix     du_dy_left,du_dy_right;
 586         fix     dv_dy_left,dv_dy_right;
 587         fix     dz_dy_left,dz_dy_right;
 588         fix     dl_dy_left,dl_dy_right;
 589         fix     recip_dyl, recip_dyr;
 590         int     max_y_vertex;
 591         fix     xleft,xright,uleft,vleft,uright,vright,zleft,zright,lleft,lright;
 592         int     next_break_left, next_break_right;
 593
 594         g3ds_vertex *v3d;
 595
 596         //remove stupid warnings in compile
 597         dl_dy_left = F1_0;
 598         dl_dy_right = F1_0;
 599         lleft = F1_0;
 600         lright = F1_0;
 601
 602         v3d = t->verts;
 603
 604         // Determine top and bottom y coords.
 605         compute_y_bounds(t,&vlt,&vlb,&vrt,&vrb,&max_y_vertex);
 606
 607         // Set top and bottom (of entire texture map) y coordinates.
 608         topy = f2i(v3d[vlt].y2d);
 609         boty = f2i(v3d[max_y_vertex].y2d);
 610         if (topy > Window_clip_bot)
 611                 return;
 612         if (boty > Window_clip_bot)
 613                 boty = Window_clip_bot;
 614
 615         // Set amount to change x coordinate for each advance to next scanline.
 616         dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
 617         if (dy < FIX_RECIP_TABLE_SIZE)
 618                 recip_dyl = fix_recip[dy];
 619         else
 620                 recip_dyl = F1_0/dy;
 621
 622         dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dyl);
 623         du_dy_left = compute_du_dy(t,vlt,vlb, recip_dyl);
 624         dv_dy_left = compute_dv_dy(t,vlt,vlb, recip_dyl);
 625         dz_dy_left = compute_dz_dy(t,vlt,vlb, recip_dyl);
 626
 627         dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
 628         if (dy < FIX_RECIP_TABLE_SIZE)
 629                 recip_dyr = fix_recip[dy];
 630         else
 631                 recip_dyr = F1_0/dy;
 632
 633         du_dy_right = compute_du_dy(t,vrt,vrb, recip_dyr);
 634         dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dyr);
 635         dv_dy_right = compute_dv_dy(t,vrt,vrb, recip_dyr);
 636         dz_dy_right = compute_dz_dy(t,vrt,vrb, recip_dyr);
 637
 638         if (Lighting_enabled) {
 639                 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dyl);
 640                 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dyr);
 641
 642                 lleft = v3d[vlt].l;
 643                 lright = v3d[vrt].l;
 644         }
 645
 646         // Set initial values for x, u, v
 647         xleft = v3d[vlt].x2d;
 648         xright = v3d[vrt].x2d;
 649
 650         zleft = v3d[vlt].z;
 651         zright = v3d[vrt].z;
 652
 653         uleft = fixmul(v3d[vlt].u,zleft);
 654         uright = fixmul(v3d[vrt].u,zright);
 655         vleft = fixmul(v3d[vlt].v,zleft);
 656         vright = fixmul(v3d[vrt].v,zright);
 657
 658         // scan all rows in texture map from top through first break.
 659         next_break_left = f2i(v3d[vlb].y2d);
 660         next_break_right = f2i(v3d[vrb].y2d);
 661
 662         for (y = topy; y < boty; y++) {
 663
 664                 // See if we have reached the end of the current left edge, and if so, set
 665                 // new values for dx_dy and x,u,v
 666                 if (y == next_break_left) {
 667                         fix     recip_dy;
 668
 669                         // Handle problem of double points.  Search until y coord is different.  Cannot get
 670                         // hung in an infinite loop because we know there is a vertex with a lower y coordinate
 671                         // because in the for loop, we don't scan all spanlines.
 672                         while (y == f2i(v3d[vlb].y2d)) {
 673                                 vlt = vlb;
 674                                 vlb = prevmod(vlb,t->nv);
 675                         }
 676                         next_break_left = f2i(v3d[vlb].y2d);
 677
 678                         dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
 679                         if (dy < FIX_RECIP_TABLE_SIZE)
 680                                 recip_dy = fix_recip[dy];
 681                         else
 682                                 recip_dy = F1_0/dy;
 683
 684                         dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
 685
 686                         xleft = v3d[vlt].x2d;
 687                         zleft = v3d[vlt].z;
 688                         uleft = fixmul(v3d[vlt].u,zleft);
 689                         vleft = fixmul(v3d[vlt].v,zleft);
 690                         lleft = v3d[vlt].l;
 691
 692                         du_dy_left = compute_du_dy(t,vlt,vlb, recip_dy);
 693                         dv_dy_left = compute_dv_dy(t,vlt,vlb, recip_dy);
 694                         dz_dy_left = compute_dz_dy(t,vlt,vlb, recip_dy);
 695
 696                         if (Lighting_enabled) {
 697                                 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dy);
 698                                 lleft = v3d[vlt].l;
 699                         }
 700                 }
 701
 702                 // See if we have reached the end of the current left edge, and if so, set
 703                 // new values for dx_dy and x.  Not necessary to set new values for u,v.
 704                 if (y == next_break_right) {
 705                         fix     recip_dy;
 706
 707                         while (y == f2i(v3d[vrb].y2d)) {
 708                                 vrt = vrb;
 709                                 vrb = succmod(vrb,t->nv);
 710                         }
 711
 712                         next_break_right = f2i(v3d[vrb].y2d);
 713
 714                         dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
 715                         if (dy < FIX_RECIP_TABLE_SIZE)
 716                                 recip_dy = fix_recip[dy];
 717                         else
 718                                 recip_dy = F1_0/dy;
 719
 720                         dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
 721
 722                         xright = v3d[vrt].x2d;
 723                         zright = v3d[vrt].z;
 724                         uright = fixmul(v3d[vrt].u,zright);
 725                         vright = fixmul(v3d[vrt].v,zright);
 726
 727                         du_dy_right = compute_du_dy(t,vrt,vrb, recip_dy);
 728                         dv_dy_right = compute_dv_dy(t,vrt,vrb, recip_dy);
 729                         dz_dy_right = compute_dz_dy(t,vrt,vrb, recip_dy);
 730
 731                         if (Lighting_enabled) {
 732                                 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dy);
 733                                 lright = v3d[vrt].l;
 734                         }
 735                 }
 736
 737                 if (Lighting_enabled) {
 738                         if (y >= Window_clip_top)
 739                                 ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
 740                         lleft += dl_dy_left;
 741                         lright += dl_dy_right;
 742                 } else
 743                         if (y >= Window_clip_top)
 744                                 ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
 745
 746                 uleft += du_dy_left;
 747                 vleft += dv_dy_left;
 748
 749                 uright += du_dy_right;
 750                 vright += dv_dy_right;
 751
 752                 xleft += dx_dy_left;
 753                 xright += dx_dy_right;
 754
 755                 zleft += dz_dy_left;
 756                 zright += dz_dy_right;
 757
 758         }
 759
 760         // We can get lleft or lright out of bounds here because we compute dl_dy using fixed point values,
 761         //      but we plot an integer number of scanlines, therefore doing an integer number of additions of the delta.
 762
 763 //if (Break_on_flat)
 764 //      mprintf(0, "[%i %i %i] ", y, f2i(xleft), f2i(xright));
 765
 766         ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
 767 }
 768
 769
 770 // -------------------------------------------------------------------------------------
 771 //      Texture map current scanline using linear interpolation.
 772 // -------------------------------------------------------------------------------------
 773 void ntmap_scanline_lighted_linear(grs_bitmap *srcb, int y, fix xleft, fix xright, fix uleft, fix uright, fix vleft, fix vright, fix lleft, fix lright)
 774 {
 775         fix     u,v,l;
 776         fix     dx,recip_dx;
 777
 778         fix     du_dx,dv_dx,dl_dx;
 779
 780         u = uleft;
 781         v = vleft;
 782         l = lleft;
 783
 784         dx = f2i(xright) - f2i(xleft);
 785         if ((dx < 0) || (xright < 0) || (xleft > xright))               // the (xleft > xright) term is not redundant with (dx < 0) because dx is computed using integers
 786                 return;
 787
 788                 // setup to call assembler scanline renderer
 789                 if (dx < FIX_RECIP_TABLE_SIZE)
 790                         recip_dx = fix_recip[dx];
 791                 else
 792                         recip_dx = F1_0/dx;
 793
 794                 du_dx = fixmul(uright - uleft,recip_dx);
 795                 dv_dx = fixmul(vright - vleft,recip_dx);
 796
 797                 fx_u = uleft;
 798                 fx_v = vleft;
 799                 fx_du_dx = du_dx;
 800                 fx_dv_dx = dv_dx;
 801                 fx_y = y;
 802                 fx_xright = f2i(xright);
 803                 fx_xleft = f2i(xleft);
 804                 pixptr = srcb->bm_data;
 805
 806                 switch (Lighting_enabled) {
 807                         case 0:
 808                                 //added 07/11/99 adb - prevent writing before the buffer
 809                                 if (fx_xleft < 0)
 810                                         fx_xleft = 0;
 811                                 //end addition -adb
 812
 813                                 cur_tmap_scanline_lin_nolight();
 814                                 break;
 815                         case 1:
 816                                 if (lleft < F1_0/2)
 817                                         lleft = F1_0/2;
 818                                 if (lright < F1_0/2)
 819                                         lright = F1_0/2;
 820
 821                                 if (lleft > MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS)
 822                                         lleft = MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS;
 823                                 if (lright > MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS)
 824                                         lright = MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS;
 825
 826                                 //added 07/11/99 adb - prevent writing before the buffer
 827                                 if (fx_xleft < 0)
 828                                         fx_xleft = 0;
 829                                 //end addition -adb
 830
 831 {
 832                         fix mul_thing;
 833
 834                         fx_l = lleft;
 835                         fx_dl_dx = fixmul(lright - lleft,recip_dx);
 836
 837                         //      This is a pretty ugly hack to prevent lighting overflows.
 838                         mul_thing = dx * fx_dl_dx;
 839                         if (lleft + mul_thing < 0)
 840                                 fx_dl_dx += 12;
 841                         else if (lleft + mul_thing > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2))
 842                                 fx_dl_dx -= 12;
 843 }
 844
 845                                 fx_l = lleft;
 846                                 dl_dx = fixmul(lright - lleft,recip_dx);
 847                                 fx_dl_dx = dl_dx;
 848                                 cur_tmap_scanline_lin();
 849                                 break;
 850                         case 2:
 851 #ifdef EDITOR_TMAP
 852                                 fx_xright = f2i(xright);
 853                                 fx_xleft = f2i(xleft);
 854                                 tmap_flat_color = 1;
 855                                 cur_tmap_scanline_flat();
 856 #else
 857                                 Int3(); //      Illegal, called an editor only routine!
 858 #endif
 859                                 break;
 860                 }
 861 }
 862
 863 // -------------------------------------------------------------------------------------
 864 //      Render a texture map with lighting using perspective interpolation in inner and outer loops.
 865 // -------------------------------------------------------------------------------------
 866 void ntexture_map_lighted_linear(grs_bitmap *srcb, g3ds_tmap *t)
 867 {
 868         int     vlt,vrt,vlb,vrb;        // vertex left top, vertex right top, vertex left bottom, vertex right bottom
 869         int     topy,boty,y, dy;
 870         fix     dx_dy_left,dx_dy_right;
 871         fix     du_dy_left,du_dy_right;
 872         fix     dv_dy_left,dv_dy_right;
 873         fix     dl_dy_left,dl_dy_right;
 874         int     max_y_vertex;
 875         fix     xleft,xright,uleft,vleft,uright,vright,lleft,lright;
 876         int     next_break_left, next_break_right;
 877         fix     recip_dyl, recip_dyr;
 878
 879         g3ds_vertex *v3d;
 880
 881         //remove stupid warnings in compile
 882         dl_dy_left = F1_0;
 883         dl_dy_right = F1_0;
 884         lleft = F1_0;
 885         lright = F1_0;
 886
 887         v3d = t->verts;
 888
 889         // Determine top and bottom y coords.
 890         compute_y_bounds(t,&vlt,&vlb,&vrt,&vrb,&max_y_vertex);
 891
 892         // Set top and bottom (of entire texture map) y coordinates.
 893         topy = f2i(v3d[vlt].y2d);
 894         boty = f2i(v3d[max_y_vertex].y2d);
 895
 896         if (topy > Window_clip_bot)
 897                 return;
 898         if (boty > Window_clip_bot)
 899                 boty = Window_clip_bot;
 900
 901         dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
 902         if (dy < FIX_RECIP_TABLE_SIZE)
 903                 recip_dyl = fix_recip[dy];
 904         else
 905                 recip_dyl = F1_0/dy;
 906
 907         dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
 908         if (dy < FIX_RECIP_TABLE_SIZE)
 909                 recip_dyr = fix_recip[dy];
 910         else
 911                 recip_dyr = F1_0/dy;
 912
 913         // Set amount to change x coordinate for each advance to next scanline.
 914         dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dyl);
 915         dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dyr);
 916
 917         du_dy_left = compute_du_dy_lin(t,vlt,vlb, recip_dyl);
 918         du_dy_right = compute_du_dy_lin(t,vrt,vrb, recip_dyr);
 919
 920         dv_dy_left = compute_dv_dy_lin(t,vlt,vlb, recip_dyl);
 921         dv_dy_right = compute_dv_dy_lin(t,vrt,vrb, recip_dyr);
 922
 923         if (Lighting_enabled) {
 924                 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dyl);
 925                 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dyr);
 926
 927                 lleft = v3d[vlt].l;
 928                 lright = v3d[vrt].l;
 929         }
 930
 931         // Set initial values for x, u, v
 932         xleft = v3d[vlt].x2d;
 933         xright = v3d[vrt].x2d;
 934
 935         uleft = v3d[vlt].u;
 936         uright = v3d[vrt].u;
 937         vleft = v3d[vlt].v;
 938         vright = v3d[vrt].v;
 939
 940         // scan all rows in texture map from top through first break.
 941         next_break_left = f2i(v3d[vlb].y2d);
 942         next_break_right = f2i(v3d[vrb].y2d);
 943
 944         for (y = topy; y < boty; y++) {
 945
 946                 // See if we have reached the end of the current left edge, and if so, set
 947                 // new values for dx_dy and x,u,v
 948                 if (y == next_break_left) {
 949                         fix     recip_dy;
 950
 951                         // Handle problem of double points.  Search until y coord is different.  Cannot get
 952                         // hung in an infinite loop because we know there is a vertex with a lower y coordinate
 953                         // because in the for loop, we don't scan all spanlines.
 954                         while (y == f2i(v3d[vlb].y2d)) {
 955                                 vlt = vlb;
 956                                 vlb = prevmod(vlb,t->nv);
 957                         }
 958                         next_break_left = f2i(v3d[vlb].y2d);
 959
 960                         dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
 961                         if (dy < FIX_RECIP_TABLE_SIZE)
 962                                 recip_dy = fix_recip[dy];
 963                         else
 964                                 recip_dy = F1_0/dy;
 965
 966                         dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
 967
 968                         xleft = v3d[vlt].x2d;
 969                         uleft = v3d[vlt].u;
 970                         vleft = v3d[vlt].v;
 971                         lleft = v3d[vlt].l;
 972
 973                         du_dy_left = compute_du_dy_lin(t,vlt,vlb, recip_dy);
 974                         dv_dy_left = compute_dv_dy_lin(t,vlt,vlb, recip_dy);
 975
 976                         if (Lighting_enabled) {
 977                                 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dy);
 978                                 lleft = v3d[vlt].l;
 979                         }
 980                 }
 981
 982                 // See if we have reached the end of the current left edge, and if so, set
 983                 // new values for dx_dy and x.  Not necessary to set new values for u,v.
 984                 if (y == next_break_right) {
 985                         fix     recip_dy;
 986
 987                         while (y == f2i(v3d[vrb].y2d)) {
 988                                 vrt = vrb;
 989                                 vrb = succmod(vrb,t->nv);
 990                         }
 991
 992                         dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
 993                         if (dy < FIX_RECIP_TABLE_SIZE)
 994                                 recip_dy = fix_recip[dy];
 995                         else
 996                                 recip_dy = F1_0/dy;
 997
 998                         next_break_right = f2i(v3d[vrb].y2d);
 999                         dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
1000
1001                         xright = v3d[vrt].x2d;
1002                         uright = v3d[vrt].u;
1003                         vright = v3d[vrt].v;
1004
1005                         du_dy_right = compute_du_dy_lin(t,vrt,vrb, recip_dy);
1006                         dv_dy_right = compute_dv_dy_lin(t,vrt,vrb, recip_dy);
1007
1008                         if (Lighting_enabled) {
1009                                 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dy);
1010                                 lright = v3d[vrt].l;
1011                         }
1012                 }
1013
1014                 if (Lighting_enabled) {
1015                         ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
1016                         lleft += dl_dy_left;
1017                         lright += dl_dy_right;
1018                 } else
1019                         ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
1020
1021                 uleft += du_dy_left;
1022                 vleft += dv_dy_left;
1023
1024                 uright += du_dy_right;
1025                 vright += dv_dy_right;
1026
1027                 xleft += dx_dy_left;
1028                 xright += dx_dy_right;
1029
1030         }
1031
1032         // We can get lleft or lright out of bounds here because we compute dl_dy using fixed point values,
1033         //      but we plot an integer number of scanlines, therefore doing an integer number of additions of the delta.
1034
1035         ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
1036 }
1037
1038 // fix  DivNum = F1_0*12;
1039
1040 extern void draw_tmap_flat(grs_bitmap *bp,int nverts,g3s_point **vertbuf);
1041
1042 // -------------------------------------------------------------------------------------
1043 // Interface from Matt's data structures to Mike's texture mapper.
1044 // -------------------------------------------------------------------------------------
1045 void draw_tmap(grs_bitmap *bp,int nverts,g3s_point **vertbuf)
1046 {
1047         int     i;
1048
1049         //      These variables are used in system which renders texture maps which lie on one scanline as a line.
1050         // fix  div_numerator;
1051         int     lighting_on_save = Lighting_on;
1052
1053         Assert(nverts <= MAX_TMAP_VERTS);
1054
1055
1056 #ifdef USE_MULT_CODE
1057         if ( !divide_table_filled ) fill_divide_table();
1058 #endif
1059
1060         // -- now called from g3_start_frame -- init_interface_vars_to_assembler();
1061
1062         //      If no transparency and seg depth is large, render as flat shaded.
1063         if ((Current_seg_depth > Max_linear_depth) && ((bp->bm_flags & 3) == 0)) {
1064                 draw_tmap_flat(bp, nverts, vertbuf);
1065                 return;
1066         }
1067
1068         if ( bp->bm_flags & BM_FLAG_RLE )
1069                 bp = rle_expand_texture( bp );          // Expand if rle'd
1070
1071         Transparency_on = bp->bm_flags & BM_FLAG_TRANSPARENT;
1072         if (bp->bm_flags & BM_FLAG_NO_LIGHTING)
1073                 Lighting_on = 0;
1074
1075
1076         // Setup texture map in Tmap1
1077         Tmap1.nv = nverts;                                              // Initialize number of vertices
1078
1079 //      div_numerator = DivNum; //f1_0*3;
1080
1081         for (i=0; i<nverts; i++) {
1082                 g3ds_vertex     *tvp = &Tmap1.verts[i];
1083                 g3s_point       *vp = vertbuf[i];
1084
1085                 tvp->x2d = vp->p3_sx;
1086                 tvp->y2d = vp->p3_sy;
1087
1088                 //      Check for overflow on fixdiv.  Will overflow on vp->z <= something small.  Allow only as low as 256.
1089                 if (vp->p3_z < 256) {
1090                         vp->p3_z = 256;
1091                         // Int3();              // we would overflow if we divided!
1092                 }
1093
1094                 tvp->z = fixdiv(F1_0*12, vp->p3_z);
1095                 tvp->u = vp->p3_u << 6; //* bp->bm_w;
1096                 tvp->v = vp->p3_v << 6; //* bp->bm_h;
1097
1098                 Assert(Lighting_on < 3);
1099
1100                 if (Lighting_on)
1101                         tvp->l = vp->p3_l * NUM_LIGHTING_LEVELS;
1102         }
1103
1104
1105         Lighting_enabled = Lighting_on;
1106
1107         // Now, call my texture mapper.
1108         if (Lighting_on) {
1109                 switch (Interpolation_method) { // 0 = choose, 1 = linear, 2 = /8 perspective, 3 = full perspective
1110                         case 0:                                                         // choose best interpolation
1111                                 per2_flag = 1;
1112                                 if (Current_seg_depth > Max_perspective_depth)
1113                                         ntexture_map_lighted_linear(bp, &Tmap1);
1114                                 else
1115                                         ntexture_map_lighted(bp, &Tmap1);
1116                                 break;
1117                         case 1:                                                         // linear interpolation
1118                                 per2_flag = 1;
1119                                 ntexture_map_lighted_linear(bp, &Tmap1);
1120                                 break;
1121                         case 2:                                                         // perspective every 8th pixel interpolation
1122                                 per2_flag = 1;
1123                                 ntexture_map_lighted(bp, &Tmap1);
1124                                 break;
1125                         case 3:                                                         // perspective every pixel interpolation
1126                                 per2_flag = 0;                                  // this hack means do divide every pixel
1127                                 ntexture_map_lighted(bp, &Tmap1);
1128                                 break;
1129                         default:
1130                                 Assert(0);                              // Illegal value for Interpolation_method, must be 0,1,2,3
1131                 }
1132         } else {
1133                 switch (Interpolation_method) { // 0 = choose, 1 = linear, 2 = /8 perspective, 3 = full perspective
1134                         case 0:                                                         // choose best interpolation
1135                                 per2_flag = 1;
1136                                 if (Current_seg_depth > Max_perspective_depth)
1137                                         ntexture_map_lighted_linear(bp, &Tmap1);
1138                                 else
1139                                         ntexture_map_lighted(bp, &Tmap1);
1140                                 break;
1141                         case 1:                                                         // linear interpolation
1142                                 per2_flag = 1;
1143                                 ntexture_map_lighted_linear(bp, &Tmap1);
1144                                 break;
1145                         case 2:                                                         // perspective every 8th pixel interpolation
1146                                 per2_flag = 1;
1147                                 ntexture_map_lighted(bp, &Tmap1);
1148                                 break;
1149                         case 3:                                                         // perspective every pixel interpolation
1150                                 per2_flag = 0;                                  // this hack means do divide every pixel
1151                                 ntexture_map_lighted(bp, &Tmap1);
1152                                 break;
1153                         default:
1154                                 Assert(0);                              // Illegal value for Interpolation_method, must be 0,1,2,3
1155                 }
1156         }
1157
1158         Lighting_on = lighting_on_save;
1159
1160 }