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: 1.2 $
  16  * $Author: bradleyb $
  17  * $Date: 2001-01-31 14:04:46 $
  18  *
  19  * Start of conversion to new texture mapper.
  20  *
  21  * $Log: not supported by cvs2svn $
  22  * Revision 1.1.1.1  2001/01/19 03:30:16  bradleyb
  23  * Import of d2x-0.0.8
  24  *
  25  * Revision 1.4  1999/10/18 00:31:55  donut
  26  * allow FP_TMAP to be used without NO_ASM
  27  *
  28  * Revision 1.3  1999/08/05 22:53:41  sekmu
  29  *
  30  * D3D patch(es) from ADB
  31  *
  32  * Revision 1.2  1999/07/07 21:31:09  donut
  33  * removed unused vars from ntmap_scanline_lighted and slightly optomized it
  34  *
  35  * Revision 1.1.1.1  1999/06/14 22:14:06  donut
  36  * Import of d1x 1.37 source.
  37  *
  38  * Revision 1.52  1995/03/14  15:13:06  john
  39  * Increased MAX_Y_Pointers to 480.
  40  *
  41  * Revision 1.51  1995/02/23  14:25:09  john
  42  * Added editor tmap.
  43  *
  44  * Revision 1.50  1995/02/20  18:22:58  john
  45  * Put all the externs in the assembly modules into tmap_inc.asm.
  46  * Also, moved all the C versions of the inner loops into a new module,
  47  * scanline.c.
  48  *
  49  * Revision 1.49  1995/02/20  17:09:11  john
  50  * Added code so that you can build the tmapper with no assembly!
  51  *
  52  * Revision 1.48  1995/01/06  11:11:30  mike
  53  * even when not in editor, have 400 lines in texture map scanline table.
  54  *
  55  * Revision 1.47  1994/12/15  16:43:25  matt
  56  * Took out code only needed by editor
  57  *
  58  * Revision 1.46  1994/12/09  22:35:37  mike
  59  * fix bug in before call to asm_tmap_scanline_per causing write of pixel onto past right border onto left.
  60  *
  61  * Revision 1.45  1994/12/06  16:31:06  mike
  62  * fix bug in asm_tmap_scanline_matt interface.
  63  *
  64  * Revision 1.44  1994/12/04  20:37:18  mike
  65  * *** empty log message ***
  66  *
  67  * Revision 1.43  1994/12/02  23:30:04  mike
  68  * optimizations.
  69  *
  70  * Revision 1.42  1994/11/30  00:57:43  mike
  71  * optimizations.
  72  *
  73  * Revision 1.41  1994/11/28  13:34:27  mike
  74  * optimizations.
  75  *
  76  * Revision 1.40  1994/11/28  01:30:01  mike
  77  * kill warning.
  78  *
  79  * Revision 1.39  1994/11/28  01:28:59  mike
  80  * optimizations.
  81  *
  82  * Revision 1.38  1994/11/21  14:08:07  john
  83  * Took out all multiple instead of divide code.
  84  *
  85  * Revision 1.37  1994/11/19  15:21:52  mike
  86  * rip out unused code.
  87  *
  88  * Revision 1.36  1994/11/14  11:42:51  mike
  89  * optimization.
  90  *
  91  * Revision 1.35  1994/11/12  16:41:36  mike
  92  * *** empty log message ***
  93  *
  94  * Revision 1.34  1994/11/10  21:28:41  mike
  95  * remove call to init_interface_vars_to_assembler.
  96  *
  97  * Revision 1.33  1994/11/10  11:08:59  mike
  98  * detail level stuff.
  99  *
 100  * Revision 1.32  1994/11/09  22:55:52  matt
 101  * Added variable Current_seg_depth for detail level optimization
 102  *
 103  * Revision 1.31  1994/11/09  19:57:31  john
 104  * Added texture rle caching.
 105  *
 106  * Revision 1.30  1994/11/09  19:54:48  mike
 107  * Call flat shader if Tmap_flat_flag set.
 108  *
 109  * Revision 1.29  1994/11/02  21:33:31  john
 110  * Added Burger Bill's optimization, ie.. 2 muls per 8 pixels.
 111  *
 112  * Revision 1.28  1994/11/02  11:32:16  john
 113  * Added code for c callable inner loop and code to
 114  * test dividing out z0.
 115  *
 116  * Revision 1.27  1994/10/28  20:54:32  matt
 117  * Added error checking
 118  *
 119  * Revision 1.26  1994/10/25  11:20:20  mike
 120  * fix bug in lighting overflow checking for one scanline tall linear texture maps.
 121  *
 122  * Revision 1.25  1994/08/03  15:40:33  mike
 123  * Prevent divide overflows, decrease occurrence of precision-caused glitches.
 124  *
 125  * Revision 1.24  1994/07/27  09:31:16  mike
 126  * Fix concave texture map problem, decrease occurrence of unimportant int 3.
 127  *
 128  * Revision 1.23  1994/06/17  12:23:31  mike
 129  * Support non-lighted texture maps.
 130  *
 131  * Revision 1.22  1994/06/11  08:10:24  mike
 132  * Fix mysterious hang bug, lighting value was out of range.
 133  *
 134  * Revision 1.21  1994/06/09  16:10:16  mike
 135  * Change SC2000 from constant to variable.
 136  *
 137  */
 138
 139 #ifdef RCS
 140 static char rcsid[] = "$Id: ntmap.c,v 1.2 2001-01-31 14:04:46 bradleyb Exp $";
 141 #endif
 142
 143 #include <conf.h>
 144
 145 #define VESA 0
 146 #define NUM_TMAPS 16
 147
 148 #define HEADLIGHT_LIGHTING 0
 149
 150 #define WIREFRAME 0
 151 #define PERSPECTIVE 1
 152
 153 #include "pstypes.h"
 154 #include "fix.h"
 155 #include "vecmat.h"
 156 #include "gr.h"
 157 #include "3d.h"
 158 #include "error.h"
 159 #include "rle.h"
 160
 161 #include "texmap.h"
 162 #include "texmapl.h"
 163 #ifdef NO_ASM
 164 #include "scanline.h"
 165 #endif
 166
 167 //#include "../main/textures.h"
 168
 169 #ifdef EDITOR
 170 #define EDITOR_TMAP 1       //if in, include extra stuff
 171 #endif
 172
 173 #define F15_5 (F1_0*15 + F0_5)
 174
 175 // Temporary texture map, interface from Matt's 3d system to Mike's texture mapper.
 176 g3ds_tmap Tmap1;
 177
 178 grs_bitmap Texmap_ptrs[NUM_TMAPS];
 179 grs_bitmap Texmap4_ptrs[NUM_TMAPS];
 180
 181 fix Range_max=0; // debug, kill me
 182
 183 int     Interpolation_method=0; // 0 = choose best method
 184 int     Lighting_on=1;                  // initialize to no lighting
 185 int     Tmap_flat_flag = 0;             //      1 = render texture maps as flat shaded polygons.
 186 int     Current_seg_depth;              // HACK INTERFACE: how far away the current segment (& thus texture) is
 187 int     Max_perspective_depth;
 188 int     Max_linear_depth;
 189 int     Max_flat_depth;
 190
 191 extern int Window_clip_left, Window_clip_bot, Window_clip_right, Window_clip_top;
 192
 193 // These variables are the interface to assembler.  They get set for each texture map, which is a real waste of time.
 194 //      They should be set only when they change, which is generally when the window bounds change.  And, even still, it's
 195 //      a pretty bad interface.
 196 int     bytes_per_row=-1;
 197 unsigned char *write_buffer;
 198 int     window_left;
 199 int     window_right;
 200 int     window_top;
 201 int     window_bottom;
 202 int     window_width;
 203 int     window_height;
 204
 205 #ifdef EDITOR_TMAP
 206 #define MAX_Y_POINTERS  600
 207 #else
 208 #define MAX_Y_POINTERS  600
 209 #endif
 210 int     y_pointers[MAX_Y_POINTERS];
 211
 212 fix fix_recip[FIX_RECIP_TABLE_SIZE];
 213
 214 int     Lighting_enabled;
 215 int     Fix_recip_table_computed=0;
 216
 217 fix fx_l, fx_u, fx_v, fx_z, fx_du_dx, fx_dv_dx, fx_dz_dx, fx_dl_dx;
 218 int fx_xleft, fx_xright, fx_y;
 219 unsigned char * pixptr;
 220 int per2_flag = 0;
 221 int Transparency_on = 0;
 222 int dither_intensity_lighting = 0;
 223
 224 ubyte * tmap_flat_cthru_table;
 225 ubyte tmap_flat_color;
 226 ubyte tmap_flat_shade_value;
 227
 228
 229
 230 // -------------------------------------------------------------------------------------
 231 void init_fix_recip_table(void)
 232 {
 233         int     i;
 234
 235         fix_recip[0] = F1_0;
 236
 237         for (i=1; i<FIX_RECIP_TABLE_SIZE; i++)
 238                 fix_recip[i] = F1_0/i;
 239
 240         Fix_recip_table_computed = 1;
 241 }
 242
 243 // -------------------------------------------------------------------------------------
 244 //      Initialize interface variables to assembler.
 245 //      These things used to be constants.  This routine is now (10/6/93) getting called for
 246 //      every texture map.  It should get called whenever the window changes, or, preferably,
 247 //      not at all.  I'm pretty sure these variables are only being used for range checking.
 248 void init_interface_vars_to_assembler(void)
 249 {
 250         grs_bitmap      *bp;
 251
 252         bp = &grd_curcanv->cv_bitmap;
 253
 254         Assert(bp!=NULL);
 255         Assert(bp->bm_data!=NULL);
 256         Assert(bp->bm_h <= MAX_Y_POINTERS);
 257
 258         //      If bytes_per_row has changed, create new table of pointers.
 259         if (bytes_per_row != (int) bp->bm_rowsize) {
 260                 int     y_val, i;
 261
 262                 bytes_per_row = (int) bp->bm_rowsize;
 263
 264                 y_val = 0;
 265                 for (i=0; i<MAX_Y_POINTERS; i++) {
 266                         y_pointers[i] = y_val;
 267                         y_val += bytes_per_row;
 268                 }
 269         }
 270
 271         write_buffer = (unsigned char *) bp->bm_data;
 272
 273         window_left = 0;
 274         window_right = (int) bp->bm_w-1;
 275         window_top = 0;
 276         window_bottom = (int) bp->bm_h-1;
 277
 278         Window_clip_left = window_left;
 279         Window_clip_right = window_right;
 280         Window_clip_top = window_top;
 281         Window_clip_bot = window_bottom;
 282
 283         window_width = bp->bm_w;
 284         window_height = bp->bm_h;
 285
 286         if (!Fix_recip_table_computed)
 287                 init_fix_recip_table();
 288 }
 289
 290 // -------------------------------------------------------------------------------------
 291 //                             VARIABLES
 292 extern g3ds_tmap Tmap1;
 293
 294 // -------------------------------------------------------------------------------------
 295 //      Returns number preceding val modulo modulus.
 296 //      prevmod(3,4) = 2
 297 //      prevmod(0,4) = 3
 298 int prevmod(int val,int modulus)
 299 {
 300         if (val > 0)
 301                 return val-1;
 302         else
 303                 return modulus-1;
 304 //      return (val + modulus - 1) % modulus;
 305 }
 306
 307
 308 //      Returns number succeeding val modulo modulus.
 309 //      succmod(3,4) = 0
 310 //      succmod(0,4) = 1
 311 int succmod(int val,int modulus)
 312 {
 313         if (val < modulus-1)
 314                 return val+1;
 315         else
 316                 return 0;
 317
 318 //      return (val + 1) % modulus;
 319 }
 320
 321 // -------------------------------------------------------------------------------------
 322 //      Select topmost vertex (minimum y coordinate) and bottommost (maximum y coordinate) in
 323 //      texture map.  If either is part of a horizontal edge, then select leftmost vertex for
 324 //      top, rightmost vertex for bottom.
 325 //      Important: Vertex is selected with integer precision.  So, if there are vertices at
 326 //      (0.0,0.7) and (0.5,0.3), the first vertex is selected, because they y coordinates are
 327 //      considered the same, so the smaller x is favored.
 328 //      Parameters:
 329 //              nv              number of vertices
 330 //              v3d     pointer to 3d vertices containing u,v,x2d,y2d coordinates
 331 //      Results in:
 332 //              *min_y_ind
 333 //              *max_y_ind
 334 // -------------------------------------------------------------------------------------
 335 void compute_y_bounds(g3ds_tmap *t, int *vlt, int *vlb, int *vrt, int *vrb,int *bottom_y_ind)
 336 {
 337         int     i;
 338         int     min_y,max_y;
 339         int     min_y_ind;
 340         int     original_vrt;
 341         fix     min_x;
 342
 343         // Scan all vertices, set min_y_ind to vertex with smallest y coordinate.
 344         min_y = f2i(t->verts[0].y2d);
 345         max_y = min_y;
 346         min_y_ind = 0;
 347         min_x = f2i(t->verts[0].x2d);
 348         *bottom_y_ind = 0;
 349
 350         for (i=1; i<t->nv; i++) {
 351                 if (f2i(t->verts[i].y2d) < min_y) {
 352                         min_y = f2i(t->verts[i].y2d);
 353                         min_y_ind = i;
 354                         min_x = f2i(t->verts[i].x2d);
 355                 } else if (f2i(t->verts[i].y2d) == min_y) {
 356                         if (f2i(t->verts[i].x2d) < min_x) {
 357                                 min_y_ind = i;
 358                                 min_x = f2i(t->verts[i].x2d);
 359                         }
 360                 }
 361                 if (f2i(t->verts[i].y2d) > max_y) {
 362                         max_y = f2i(t->verts[i].y2d);
 363                         *bottom_y_ind = i;
 364                 }
 365         }
 366
 367 //--removed mk, 11/27/94--      //      Check for a non-upright-hourglass polygon and fix, if necessary, by bashing a y coordinate.
 368 //--removed mk, 11/27/94--      //      min_y_ind = index of minimum y coordinate, *bottom_y_ind = index of maximum y coordinate
 369 //--removed mk, 11/27/94--{
 370 //--removed mk, 11/27/94--      int     max_temp, min_temp;
 371 //--removed mk, 11/27/94--
 372 //--removed mk, 11/27/94--      max_temp = *bottom_y_ind;
 373 //--removed mk, 11/27/94--      if (*bottom_y_ind < min_y_ind)
 374 //--removed mk, 11/27/94--              max_temp += t->nv;
 375 //--removed mk, 11/27/94--
 376 //--removed mk, 11/27/94--      for (i=min_y_ind; i<max_temp; i++) {
 377 //--removed mk, 11/27/94--              if (f2i(t->verts[i%t->nv].y2d) > f2i(t->verts[(i+1)%t->nv].y2d)) {
 378 //--removed mk, 11/27/94--                      Int3();
 379 //--removed mk, 11/27/94--                      t->verts[(i+1)%t->nv].y2d = t->verts[i%t->nv].y2d;
 380 //--removed mk, 11/27/94--              }
 381 //--removed mk, 11/27/94--      }
 382 //--removed mk, 11/27/94--
 383 //--removed mk, 11/27/94--      min_temp = min_y_ind;
 384 //--removed mk, 11/27/94--      if (min_y_ind < *bottom_y_ind)
 385 //--removed mk, 11/27/94--              min_temp += t->nv;
 386 //--removed mk, 11/27/94--
 387 //--removed mk, 11/27/94--      for (i=*bottom_y_ind; i<min_temp; i++) {
 388 //--removed mk, 11/27/94--              if (f2i(t->verts[i%t->nv].y2d) < f2i(t->verts[(i+1)%t->nv].y2d)) {
 389 //--removed mk, 11/27/94--                      Int3();
 390 //--removed mk, 11/27/94--                      t->verts[(i+1)%t->nv].y2d = t->verts[i%t->nv].y2d;
 391 //--removed mk, 11/27/94--              }
 392 //--removed mk, 11/27/94--      }
 393 //--removed mk, 11/27/94--}
 394
 395         // Set "vertex left top", etc. based on vertex with topmost y coordinate
 396         *vlt = min_y_ind;
 397         *vrt = *vlt;
 398         *vlb = prevmod(*vlt,t->nv);
 399         *vrb = succmod(*vrt,t->nv);
 400
 401         // If right edge is horizontal, then advance along polygon bound until it no longer is or until all
 402         // vertices have been examined.
 403         // (Left edge cannot be horizontal, because *vlt is set to leftmost point with highest y coordinate.)
 404
 405         original_vrt = *vrt;
 406
 407         while (f2i(t->verts[*vrt].y2d) == f2i(t->verts[*vrb].y2d)) {
 408                 if (succmod(*vrt,t->nv) == original_vrt) {
 409                         break;
 410                 }
 411                 *vrt = succmod(*vrt,t->nv);
 412                 *vrb = succmod(*vrt,t->nv);
 413         }
 414 }
 415
 416 // -------------------------------------------------------------------------------------
 417 //      Returns dx/dy given two vertices.
 418 //      If dy == 0, returns 0.0
 419 // -------------------------------------------------------------------------------------
 420 //--fix compute_dx_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex)
 421 //--{
 422 //--    int     dy;
 423 //--
 424 //--    // compute delta x with respect to y for any edge
 425 //--    dy = f2i(t->verts[bottom_vertex].y2d - t->verts[top_vertex].y2d) + 1;
 426 //--    if (dy)
 427 //--            return (t->verts[bottom_vertex].x2d - t->verts[top_vertex].x2d) / dy;
 428 //--    else
 429 //--            return 0;
 430 //--
 431 //--}
 432
 433 fix compute_du_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 434 {
 435         return fixmul(t->verts[bottom_vertex].u - t->verts[top_vertex].u, recip_dy);
 436 }
 437
 438
 439 fix compute_dv_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 440 {
 441         return fixmul(t->verts[bottom_vertex].v - t->verts[top_vertex].v, recip_dy);
 442 }
 443
 444 fix compute_dl_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 445 {
 446         return fixmul(t->verts[bottom_vertex].l - t->verts[top_vertex].l, recip_dy);
 447
 448 }
 449
 450 fix compute_dx_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 451 {
 452         return fixmul(t->verts[bottom_vertex].x2d - t->verts[top_vertex].x2d, recip_dy);
 453 }
 454
 455 fix compute_du_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 456 {
 457         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);
 458 }
 459
 460
 461 fix compute_dv_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 462 {
 463         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);
 464
 465 }
 466
 467 fix compute_dz_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
 468 {
 469         return fixmul(t->verts[bottom_vertex].z - t->verts[top_vertex].z, recip_dy);
 470
 471 }
 472 int Skip_short_flag=0;
 473
 474 // -------------------------------------------------------------------------------------
 475 //      Texture map current scanline in perspective.
 476 // -------------------------------------------------------------------------------------
 477 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)
 478 {
 479         fix     dx,recip_dx;
 480
 481         fx_xright = f2i(xright);
 482         //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?
 483         if (fx_xright < Window_clip_left)
 484                 return;
 485         fx_xleft = f2i(xleft);
 486         if (fx_xleft > Window_clip_right)
 487                 return;
 488         //end edit -MM
 489
 490         dx = fx_xright - fx_xleft;
 491         if ((dx < 0) || (xright < 0) || (xleft > xright))               // the (xleft > xright) term is not redundant with (dx < 0) because dx is computed using integers
 492                 return;
 493
 494         // setup to call assembler scanline renderer
 495         if (dx < FIX_RECIP_TABLE_SIZE)
 496                 recip_dx = fix_recip[dx];
 497         else
 498                 recip_dx = F1_0/dx;
 499
 500         fx_u = uleft;
 501         fx_v = vleft;
 502         fx_z = zleft;
 503
 504         fx_du_dx = fixmul(uright - uleft,recip_dx);
 505         fx_dv_dx = fixmul(vright - vleft,recip_dx);
 506         fx_dz_dx = fixmul(zright - zleft,recip_dx);
 507         fx_y = y;
 508         pixptr = srcb->bm_data;
 509
 510         switch (Lighting_enabled) {
 511                 case 0:
 512                         //added 05/17/99 Matt Mueller - prevent writing before the buffer
 513             if ((fx_y == 0) && (fx_xleft < 0))
 514                                 fx_xleft = 0;
 515                         //end addition -MM
 516                         if (fx_xright > Window_clip_right)
 517                                 fx_xright = Window_clip_right;
 518
 519                         #if (defined(NO_ASM) && !defined(ASM_PER)) || defined(FP_TMAP)
 520                                 c_tmap_scanline_per_nolight();
 521                         #else
 522                                 asm_tmap_scanline_per();
 523                         #endif
 524                         break;
 525                 case 1: {
 526                         fix     mul_thing;
 527
 528                         if (lleft < 0) lleft = 0;
 529                         if (lright < 0) lright = 0;
 530                         if (lleft > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2)) lleft = (NUM_LIGHTING_LEVELS*F1_0-F1_0/2);
 531                         if (lright > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2)) lright = (NUM_LIGHTING_LEVELS*F1_0-F1_0/2);
 532
 533                         fx_l = lleft;
 534                         fx_dl_dx = fixmul(lright - lleft,recip_dx);
 535
 536                         //      This is a pretty ugly hack to prevent lighting overflows.
 537                         mul_thing = dx * fx_dl_dx;
 538                         if (lleft + mul_thing < 0)
 539                                 fx_dl_dx += 12;
 540                         else if (lleft + mul_thing > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2))
 541                                 fx_dl_dx -= 12;
 542
 543                         //added 05/17/99 Matt Mueller - prevent writing before the buffer
 544             if ((fx_y == 0) && (fx_xleft < 0))
 545                                 fx_xleft = 0;
 546                         //end addition -MM
 547                         if (fx_xright > Window_clip_right)
 548                                 fx_xright = Window_clip_right;
 549
 550                         #if (defined(NO_ASM) && !defined(ASM_PER)) || defined(FP_TMAP)
 551                                 c_tmap_scanline_per();
 552                         #else
 553                                 asm_tmap_scanline_per();
 554                         #endif
 555                         break;
 556                 }
 557                 case 2:
 558 #ifdef EDITOR_TMAP
 559                         fx_xright = f2i(xright);
 560                         fx_xleft = f2i(xleft);
 561
 562 #if defined(FL1_WITH_FLAT) || defined(NO_ASM)
 563                         tmap_flat_color = 1;
 564                         #ifdef NO_ASM
 565                         c_tmap_scanline_flat();
 566                         #else
 567                         asm_tmap_scanline_flat();
 568                         #endif
 569 #else
 570                         asm_tmap_scanline_matt();
 571 #endif
 572 #else
 573                         Int3(); //      Illegal, called an editor only routine!
 574 #endif
 575                         break;
 576         }
 577
 578 }
 579
 580 int Do_vertical_scan=0;
 581
 582 int     Break_on_flat=0;
 583
 584 // -------------------------------------------------------------------------------------
 585 //      Render a texture map with lighting using perspective interpolation in inner and outer loops.
 586 // -------------------------------------------------------------------------------------
 587 void ntexture_map_lighted(grs_bitmap *srcb, g3ds_tmap *t)
 588 {
 589         int     vlt,vrt,vlb,vrb;        // vertex left top, vertex right top, vertex left bottom, vertex right bottom
 590         int     topy,boty,y, dy;
 591         fix     dx_dy_left,dx_dy_right;
 592         fix     du_dy_left,du_dy_right;
 593         fix     dv_dy_left,dv_dy_right;
 594         fix     dz_dy_left,dz_dy_right;
 595         fix     dl_dy_left,dl_dy_right;
 596         fix     recip_dyl, recip_dyr;
 597         int     max_y_vertex;
 598         fix     xleft,xright,uleft,vleft,uright,vright,zleft,zright,lleft,lright;
 599         int     next_break_left, next_break_right;
 600
 601         g3ds_vertex *v3d;
 602
 603         //remove stupid warnings in compile
 604         dl_dy_left = F1_0;
 605         dl_dy_right = F1_0;
 606         lleft = F1_0;
 607         lright = F1_0;
 608
 609         v3d = t->verts;
 610
 611         // Determine top and bottom y coords.
 612         compute_y_bounds(t,&vlt,&vlb,&vrt,&vrb,&max_y_vertex);
 613
 614         // Set top and bottom (of entire texture map) y coordinates.
 615         topy = f2i(v3d[vlt].y2d);
 616         boty = f2i(v3d[max_y_vertex].y2d);
 617         if (topy > Window_clip_bot)
 618                 return;
 619         if (boty > Window_clip_bot)
 620                 boty = Window_clip_bot;
 621
 622         // Set amount to change x coordinate for each advance to next scanline.
 623         dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
 624         if (dy < FIX_RECIP_TABLE_SIZE)
 625                 recip_dyl = fix_recip[dy];
 626         else
 627                 recip_dyl = F1_0/dy;
 628
 629         dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dyl);
 630         du_dy_left = compute_du_dy(t,vlt,vlb, recip_dyl);
 631         dv_dy_left = compute_dv_dy(t,vlt,vlb, recip_dyl);
 632         dz_dy_left = compute_dz_dy(t,vlt,vlb, recip_dyl);
 633
 634         dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
 635         if (dy < FIX_RECIP_TABLE_SIZE)
 636                 recip_dyr = fix_recip[dy];
 637         else
 638                 recip_dyr = F1_0/dy;
 639
 640         du_dy_right = compute_du_dy(t,vrt,vrb, recip_dyr);
 641         dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dyr);
 642         dv_dy_right = compute_dv_dy(t,vrt,vrb, recip_dyr);
 643         dz_dy_right = compute_dz_dy(t,vrt,vrb, recip_dyr);
 644
 645         if (Lighting_enabled) {
 646                 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dyl);
 647                 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dyr);
 648
 649                 lleft = v3d[vlt].l;
 650                 lright = v3d[vrt].l;
 651         }
 652
 653         // Set initial values for x, u, v
 654         xleft = v3d[vlt].x2d;
 655         xright = v3d[vrt].x2d;
 656
 657         zleft = v3d[vlt].z;
 658         zright = v3d[vrt].z;
 659
 660         uleft = fixmul(v3d[vlt].u,zleft);
 661         uright = fixmul(v3d[vrt].u,zright);
 662         vleft = fixmul(v3d[vlt].v,zleft);
 663         vright = fixmul(v3d[vrt].v,zright);
 664
 665         // scan all rows in texture map from top through first break.
 666         next_break_left = f2i(v3d[vlb].y2d);
 667         next_break_right = f2i(v3d[vrb].y2d);
 668
 669         for (y = topy; y < boty; y++) {
 670
 671                 // See if we have reached the end of the current left edge, and if so, set
 672                 // new values for dx_dy and x,u,v
 673                 if (y == next_break_left) {
 674                         fix     recip_dy;
 675
 676                         // Handle problem of double points.  Search until y coord is different.  Cannot get
 677                         // hung in an infinite loop because we know there is a vertex with a lower y coordinate
 678                         // because in the for loop, we don't scan all spanlines.
 679                         while (y == f2i(v3d[vlb].y2d)) {
 680                                 vlt = vlb;
 681                                 vlb = prevmod(vlb,t->nv);
 682                         }
 683                         next_break_left = f2i(v3d[vlb].y2d);
 684
 685                         dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
 686                         if (dy < FIX_RECIP_TABLE_SIZE)
 687                                 recip_dy = fix_recip[dy];
 688                         else
 689                                 recip_dy = F1_0/dy;
 690
 691                         dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
 692
 693                         xleft = v3d[vlt].x2d;
 694                         zleft = v3d[vlt].z;
 695                         uleft = fixmul(v3d[vlt].u,zleft);
 696                         vleft = fixmul(v3d[vlt].v,zleft);
 697                         lleft = v3d[vlt].l;
 698
 699                         du_dy_left = compute_du_dy(t,vlt,vlb, recip_dy);
 700                         dv_dy_left = compute_dv_dy(t,vlt,vlb, recip_dy);
 701                         dz_dy_left = compute_dz_dy(t,vlt,vlb, recip_dy);
 702
 703                         if (Lighting_enabled) {
 704                                 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dy);
 705                                 lleft = v3d[vlt].l;
 706                         }
 707                 }
 708
 709                 // See if we have reached the end of the current left edge, and if so, set
 710                 // new values for dx_dy and x.  Not necessary to set new values for u,v.
 711                 if (y == next_break_right) {
 712                         fix     recip_dy;
 713
 714                         while (y == f2i(v3d[vrb].y2d)) {
 715                                 vrt = vrb;
 716                                 vrb = succmod(vrb,t->nv);
 717                         }
 718
 719                         next_break_right = f2i(v3d[vrb].y2d);
 720
 721                         dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
 722                         if (dy < FIX_RECIP_TABLE_SIZE)
 723                                 recip_dy = fix_recip[dy];
 724                         else
 725                                 recip_dy = F1_0/dy;
 726
 727                         dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
 728
 729                         xright = v3d[vrt].x2d;
 730                         zright = v3d[vrt].z;
 731                         uright = fixmul(v3d[vrt].u,zright);
 732                         vright = fixmul(v3d[vrt].v,zright);
 733
 734                         du_dy_right = compute_du_dy(t,vrt,vrb, recip_dy);
 735                         dv_dy_right = compute_dv_dy(t,vrt,vrb, recip_dy);
 736                         dz_dy_right = compute_dz_dy(t,vrt,vrb, recip_dy);
 737
 738                         if (Lighting_enabled) {
 739                                 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dy);
 740                                 lright = v3d[vrt].l;
 741                         }
 742                 }
 743
 744                 if (Lighting_enabled) {
 745                         if (y >= Window_clip_top)
 746                                 ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
 747                         lleft += dl_dy_left;
 748                         lright += dl_dy_right;
 749                 } else
 750                         if (y >= Window_clip_top)
 751                                 ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
 752
 753                 uleft += du_dy_left;
 754                 vleft += dv_dy_left;
 755
 756                 uright += du_dy_right;
 757                 vright += dv_dy_right;
 758
 759                 xleft += dx_dy_left;
 760                 xright += dx_dy_right;
 761
 762                 zleft += dz_dy_left;
 763                 zright += dz_dy_right;
 764
 765         }
 766
 767         // We can get lleft or lright out of bounds here because we compute dl_dy using fixed point values,
 768         //      but we plot an integer number of scanlines, therefore doing an integer number of additions of the delta.
 769
 770 //if (Break_on_flat)
 771 //      mprintf(0, "[%i %i %i] ", y, f2i(xleft), f2i(xright));
 772
 773         ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
 774 }
 775
 776
 777 // -------------------------------------------------------------------------------------
 778 //      Texture map current scanline using linear interpolation.
 779 // -------------------------------------------------------------------------------------
 780 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)
 781 {
 782         fix     u,v,l;
 783         fix     dx,recip_dx;
 784
 785         fix     du_dx,dv_dx,dl_dx;
 786
 787         u = uleft;
 788         v = vleft;
 789         l = lleft;
 790
 791         dx = f2i(xright) - f2i(xleft);
 792         if ((dx < 0) || (xright < 0) || (xleft > xright))               // the (xleft > xright) term is not redundant with (dx < 0) because dx is computed using integers
 793                 return;
 794
 795                 // setup to call assembler scanline renderer
 796                 if (dx < FIX_RECIP_TABLE_SIZE)
 797                         recip_dx = fix_recip[dx];
 798                 else
 799                         recip_dx = F1_0/dx;
 800
 801                 du_dx = fixmul(uright - uleft,recip_dx);
 802                 dv_dx = fixmul(vright - vleft,recip_dx);
 803
 804                 fx_u = uleft;
 805                 fx_v = vleft;
 806                 fx_du_dx = du_dx;
 807                 fx_dv_dx = dv_dx;
 808                 fx_y = y;
 809                 fx_xright = f2i(xright);
 810                 fx_xleft = f2i(xleft);
 811                 pixptr = srcb->bm_data;
 812
 813                 switch (Lighting_enabled) {
 814                         case 0:
 815                                 //added 07/11/99 adb - prevent writing before the buffer
 816                                 if (fx_xleft < 0)
 817                                         fx_xleft = 0;
 818                                 //end addition -adb
 819
 820                                 #ifdef NO_ASM
 821                                         c_tmap_scanline_lin_nolight();
 822                                 #else
 823                                         #ifdef NO_ASM_NOLIGHT
 824                                         asm_tmap_scanline_lin_lighted();
 825                                         #else
 826                                         asm_tmap_scanline_lin();
 827                                         #endif
 828                                 #endif
 829                                 break;
 830                         case 1:
 831                                 if (lleft < F1_0/2)
 832                                         lleft = F1_0/2;
 833                                 if (lright < F1_0/2)
 834                                         lright = F1_0/2;
 835
 836                                 if (lleft > MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS)
 837                                         lleft = MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS;
 838                                 if (lright > MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS)
 839                                         lright = MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS;
 840
 841                                 //added 07/11/99 adb - prevent writing before the buffer
 842                                 if (fx_xleft < 0)
 843                                         fx_xleft = 0;
 844                                 //end addition -adb
 845
 846 {
 847                         fix mul_thing;
 848
 849                         fx_l = lleft;
 850                         fx_dl_dx = fixmul(lright - lleft,recip_dx);
 851
 852                         //      This is a pretty ugly hack to prevent lighting overflows.
 853                         mul_thing = dx * fx_dl_dx;
 854                         if (lleft + mul_thing < 0)
 855                                 fx_dl_dx += 12;
 856                         else if (lleft + mul_thing > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2))
 857                                 fx_dl_dx -= 12;
 858 }
 859
 860                                 fx_l = lleft;
 861                                 dl_dx = fixmul(lright - lleft,recip_dx);
 862                                 fx_dl_dx = dl_dx;
 863                                 #ifdef NO_ASM
 864                                         c_tmap_scanline_lin();
 865                                 #else
 866                                         asm_tmap_scanline_lin_lighted();
 867                                 #endif
 868                                 break;
 869                         case 2:
 870 #ifdef EDITOR_TMAP
 871                                 fx_xright = f2i(xright);
 872                                 fx_xleft = f2i(xleft);
 873 #if defined(FL1_WITH_FLAT) || defined(NO_ASM)
 874                                 tmap_flat_color = 1;
 875                                 #ifdef NO_ASM
 876                                 c_tmap_scanline_flat();
 877                                 #else
 878                                 asm_tmap_scanline_flat();
 879                                 #endif
 880 #else
 881                                 asm_tmap_scanline_matt();
 882 #endif
 883 #else
 884                                 Int3(); //      Illegal, called an editor only routine!
 885 #endif
 886                                 break;
 887                 }
 888 }
 889
 890 // -------------------------------------------------------------------------------------
 891 //      Render a texture map with lighting using perspective interpolation in inner and outer loops.
 892 // -------------------------------------------------------------------------------------
 893 void ntexture_map_lighted_linear(grs_bitmap *srcb, g3ds_tmap *t)
 894 {
 895         int     vlt,vrt,vlb,vrb;        // vertex left top, vertex right top, vertex left bottom, vertex right bottom
 896         int     topy,boty,y, dy;
 897         fix     dx_dy_left,dx_dy_right;
 898         fix     du_dy_left,du_dy_right;
 899         fix     dv_dy_left,dv_dy_right;
 900         fix     dl_dy_left,dl_dy_right;
 901         int     max_y_vertex;
 902         fix     xleft,xright,uleft,vleft,uright,vright,lleft,lright;
 903         int     next_break_left, next_break_right;
 904         fix     recip_dyl, recip_dyr;
 905
 906         g3ds_vertex *v3d;
 907
 908         //remove stupid warnings in compile
 909         dl_dy_left = F1_0;
 910         dl_dy_right = F1_0;
 911         lleft = F1_0;
 912         lright = F1_0;
 913
 914         v3d = t->verts;
 915
 916         // Determine top and bottom y coords.
 917         compute_y_bounds(t,&vlt,&vlb,&vrt,&vrb,&max_y_vertex);
 918
 919         // Set top and bottom (of entire texture map) y coordinates.
 920         topy = f2i(v3d[vlt].y2d);
 921         boty = f2i(v3d[max_y_vertex].y2d);
 922
 923         if (topy > Window_clip_bot)
 924                 return;
 925         if (boty > Window_clip_bot)
 926                 boty = Window_clip_bot;
 927
 928         dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
 929         if (dy < FIX_RECIP_TABLE_SIZE)
 930                 recip_dyl = fix_recip[dy];
 931         else
 932                 recip_dyl = F1_0/dy;
 933
 934         dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
 935         if (dy < FIX_RECIP_TABLE_SIZE)
 936                 recip_dyr = fix_recip[dy];
 937         else
 938                 recip_dyr = F1_0/dy;
 939
 940         // Set amount to change x coordinate for each advance to next scanline.
 941         dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dyl);
 942         dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dyr);
 943
 944         du_dy_left = compute_du_dy_lin(t,vlt,vlb, recip_dyl);
 945         du_dy_right = compute_du_dy_lin(t,vrt,vrb, recip_dyr);
 946
 947         dv_dy_left = compute_dv_dy_lin(t,vlt,vlb, recip_dyl);
 948         dv_dy_right = compute_dv_dy_lin(t,vrt,vrb, recip_dyr);
 949
 950         if (Lighting_enabled) {
 951                 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dyl);
 952                 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dyr);
 953
 954                 lleft = v3d[vlt].l;
 955                 lright = v3d[vrt].l;
 956         }
 957
 958         // Set initial values for x, u, v
 959         xleft = v3d[vlt].x2d;
 960         xright = v3d[vrt].x2d;
 961
 962         uleft = v3d[vlt].u;
 963         uright = v3d[vrt].u;
 964         vleft = v3d[vlt].v;
 965         vright = v3d[vrt].v;
 966
 967         // scan all rows in texture map from top through first break.
 968         next_break_left = f2i(v3d[vlb].y2d);
 969         next_break_right = f2i(v3d[vrb].y2d);
 970
 971         for (y = topy; y < boty; y++) {
 972
 973                 // See if we have reached the end of the current left edge, and if so, set
 974                 // new values for dx_dy and x,u,v
 975                 if (y == next_break_left) {
 976                         fix     recip_dy;
 977
 978                         // Handle problem of double points.  Search until y coord is different.  Cannot get
 979                         // hung in an infinite loop because we know there is a vertex with a lower y coordinate
 980                         // because in the for loop, we don't scan all spanlines.
 981                         while (y == f2i(v3d[vlb].y2d)) {
 982                                 vlt = vlb;
 983                                 vlb = prevmod(vlb,t->nv);
 984                         }
 985                         next_break_left = f2i(v3d[vlb].y2d);
 986
 987                         dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
 988                         if (dy < FIX_RECIP_TABLE_SIZE)
 989                                 recip_dy = fix_recip[dy];
 990                         else
 991                                 recip_dy = F1_0/dy;
 992
 993                         dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
 994
 995                         xleft = v3d[vlt].x2d;
 996                         uleft = v3d[vlt].u;
 997                         vleft = v3d[vlt].v;
 998                         lleft = v3d[vlt].l;
 999
1000                         du_dy_left = compute_du_dy_lin(t,vlt,vlb, recip_dy);
1001                         dv_dy_left = compute_dv_dy_lin(t,vlt,vlb, recip_dy);
1002
1003                         if (Lighting_enabled) {
1004                                 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dy);
1005                                 lleft = v3d[vlt].l;
1006                         }
1007                 }
1008
1009                 // See if we have reached the end of the current left edge, and if so, set
1010                 // new values for dx_dy and x.  Not necessary to set new values for u,v.
1011                 if (y == next_break_right) {
1012                         fix     recip_dy;
1013
1014                         while (y == f2i(v3d[vrb].y2d)) {
1015                                 vrt = vrb;
1016                                 vrb = succmod(vrb,t->nv);
1017                         }
1018
1019                         dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
1020                         if (dy < FIX_RECIP_TABLE_SIZE)
1021                                 recip_dy = fix_recip[dy];
1022                         else
1023                                 recip_dy = F1_0/dy;
1024
1025                         next_break_right = f2i(v3d[vrb].y2d);
1026                         dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
1027
1028                         xright = v3d[vrt].x2d;
1029                         uright = v3d[vrt].u;
1030                         vright = v3d[vrt].v;
1031
1032                         du_dy_right = compute_du_dy_lin(t,vrt,vrb, recip_dy);
1033                         dv_dy_right = compute_dv_dy_lin(t,vrt,vrb, recip_dy);
1034
1035                         if (Lighting_enabled) {
1036                                 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dy);
1037                                 lright = v3d[vrt].l;
1038                         }
1039                 }
1040
1041                 if (Lighting_enabled) {
1042                         ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
1043                         lleft += dl_dy_left;
1044                         lright += dl_dy_right;
1045                 } else
1046                         ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
1047
1048                 uleft += du_dy_left;
1049                 vleft += dv_dy_left;
1050
1051                 uright += du_dy_right;
1052                 vright += dv_dy_right;
1053
1054                 xleft += dx_dy_left;
1055                 xright += dx_dy_right;
1056
1057         }
1058
1059         // We can get lleft or lright out of bounds here because we compute dl_dy using fixed point values,
1060         //      but we plot an integer number of scanlines, therefore doing an integer number of additions of the delta.
1061
1062         ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
1063 }
1064
1065 // fix  DivNum = F1_0*12;
1066
1067 extern void draw_tmap_flat(grs_bitmap *bp,int nverts,g3s_point **vertbuf);
1068
1069 // -------------------------------------------------------------------------------------
1070 // Interface from Matt's data structures to Mike's texture mapper.
1071 // -------------------------------------------------------------------------------------
1072 void draw_tmap(grs_bitmap *bp,int nverts,g3s_point **vertbuf)
1073 {
1074         int     i;
1075
1076         //      These variables are used in system which renders texture maps which lie on one scanline as a line.
1077         // fix  div_numerator;
1078         int     lighting_on_save = Lighting_on;
1079
1080         Assert(nverts <= MAX_TMAP_VERTS);
1081
1082
1083 #ifdef USE_MULT_CODE
1084         if ( !divide_table_filled ) fill_divide_table();
1085 #endif
1086
1087         // -- now called from g3_start_frame -- init_interface_vars_to_assembler();
1088
1089         //      If no transparency and seg depth is large, render as flat shaded.
1090         if ((Current_seg_depth > Max_linear_depth) && ((bp->bm_flags & 3) == 0)) {
1091                 draw_tmap_flat(bp, nverts, vertbuf);
1092                 return;
1093         }
1094
1095         if ( bp->bm_flags & BM_FLAG_RLE )
1096                 bp = rle_expand_texture( bp );          // Expand if rle'd
1097
1098         Transparency_on = bp->bm_flags & BM_FLAG_TRANSPARENT;
1099         if (bp->bm_flags & BM_FLAG_NO_LIGHTING)
1100                 Lighting_on = 0;
1101
1102
1103         // Setup texture map in Tmap1
1104         Tmap1.nv = nverts;                                              // Initialize number of vertices
1105
1106 //      div_numerator = DivNum; //f1_0*3;
1107
1108         for (i=0; i<nverts; i++) {
1109                 g3ds_vertex     *tvp = &Tmap1.verts[i];
1110                 g3s_point       *vp = vertbuf[i];
1111
1112                 tvp->x2d = vp->p3_sx;
1113                 tvp->y2d = vp->p3_sy;
1114
1115                 //      Check for overflow on fixdiv.  Will overflow on vp->z <= something small.  Allow only as low as 256.
1116                 if (vp->p3_z < 256) {
1117                         vp->p3_z = 256;
1118                         // Int3();              // we would overflow if we divided!
1119                 }
1120
1121                 tvp->z = fixdiv(F1_0*12, vp->p3_z);
1122                 tvp->u = vp->p3_u << 6; //* bp->bm_w;
1123                 tvp->v = vp->p3_v << 6; //* bp->bm_h;
1124
1125                 Assert(Lighting_on < 3);
1126
1127                 if (Lighting_on)
1128                         tvp->l = vp->p3_l * NUM_LIGHTING_LEVELS;
1129         }
1130
1131
1132         Lighting_enabled = Lighting_on;
1133
1134         // Now, call my texture mapper.
1135         if (Lighting_on) {
1136                 switch (Interpolation_method) { // 0 = choose, 1 = linear, 2 = /8 perspective, 3 = full perspective
1137                         case 0:                                                         // choose best interpolation
1138                                 per2_flag = 1;
1139                                 if (Current_seg_depth > Max_perspective_depth)
1140                                         ntexture_map_lighted_linear(bp, &Tmap1);
1141                                 else
1142                                         ntexture_map_lighted(bp, &Tmap1);
1143                                 break;
1144                         case 1:                                                         // linear interpolation
1145                                 per2_flag = 1;
1146                                 ntexture_map_lighted_linear(bp, &Tmap1);
1147                                 break;
1148                         case 2:                                                         // perspective every 8th pixel interpolation
1149                                 per2_flag = 1;
1150                                 ntexture_map_lighted(bp, &Tmap1);
1151                                 break;
1152                         case 3:                                                         // perspective every pixel interpolation
1153                                 per2_flag = 0;                                  // this hack means do divide every pixel
1154                                 ntexture_map_lighted(bp, &Tmap1);
1155                                 break;
1156                         default:
1157                                 Assert(0);                              // Illegal value for Interpolation_method, must be 0,1,2,3
1158                 }
1159         } else {
1160                 switch (Interpolation_method) { // 0 = choose, 1 = linear, 2 = /8 perspective, 3 = full perspective
1161                         case 0:                                                         // choose best interpolation
1162                                 per2_flag = 1;
1163                                 if (Current_seg_depth > Max_perspective_depth)
1164                                         ntexture_map_lighted_linear(bp, &Tmap1);
1165                                 else
1166                                         ntexture_map_lighted(bp, &Tmap1);
1167                                 break;
1168                         case 1:                                                         // linear interpolation
1169                                 per2_flag = 1;
1170                                 ntexture_map_lighted_linear(bp, &Tmap1);
1171                                 break;
1172                         case 2:                                                         // perspective every 8th pixel interpolation
1173                                 per2_flag = 1;
1174                                 ntexture_map_lighted(bp, &Tmap1);
1175                                 break;
1176                         case 3:                                                         // perspective every pixel interpolation
1177                                 per2_flag = 0;                                  // this hack means do divide every pixel
1178                                 ntexture_map_lighted(bp, &Tmap1);
1179                                 break;
1180                         default:
1181                                 Assert(0);                              // Illegal value for Interpolation_method, must be 0,1,2,3
1182                 }
1183         }
1184
1185         Lighting_on = lighting_on_save;
1186
1187 }
1188