1 /* $Id: ntmap.c,v 1.8 2003-03-19 19:21:34 btb Exp $ */
3 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
4 SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO
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6 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
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8 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
9 FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
10 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS
11 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
12 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
17 * Start of conversion to new texture mapper.
20 * Revision 1.52 1995/03/14 15:13:06 john
21 * Increased MAX_Y_Pointers to 480.
23 * Revision 1.51 1995/02/23 14:25:09 john
26 * Revision 1.50 1995/02/20 18:22:58 john
27 * Put all the externs in the assembly modules into tmap_inc.asm.
28 * Also, moved all the C versions of the inner loops into a new module,
31 * Revision 1.49 1995/02/20 17:09:11 john
32 * Added code so that you can build the tmapper with no assembly!
34 * Revision 1.48 1995/01/06 11:11:30 mike
35 * even when not in editor, have 400 lines in texture map scanline table.
37 * Revision 1.47 1994/12/15 16:43:25 matt
38 * Took out code only needed by editor
40 * Revision 1.46 1994/12/09 22:35:37 mike
41 * fix bug in before call to asm_tmap_scanline_per causing write of pixel onto past right border onto left.
43 * Revision 1.45 1994/12/06 16:31:06 mike
44 * fix bug in asm_tmap_scanline_matt interface.
46 * Revision 1.44 1994/12/04 20:37:18 mike
47 * *** empty log message ***
49 * Revision 1.43 1994/12/02 23:30:04 mike
52 * Revision 1.42 1994/11/30 00:57:43 mike
55 * Revision 1.41 1994/11/28 13:34:27 mike
58 * Revision 1.40 1994/11/28 01:30:01 mike
61 * Revision 1.39 1994/11/28 01:28:59 mike
64 * Revision 1.38 1994/11/21 14:08:07 john
65 * Took out all multiple instead of divide code.
67 * Revision 1.37 1994/11/19 15:21:52 mike
68 * rip out unused code.
70 * Revision 1.36 1994/11/14 11:42:51 mike
73 * Revision 1.35 1994/11/12 16:41:36 mike
74 * *** empty log message ***
76 * Revision 1.34 1994/11/10 21:28:41 mike
77 * remove call to init_interface_vars_to_assembler.
79 * Revision 1.33 1994/11/10 11:08:59 mike
82 * Revision 1.32 1994/11/09 22:55:52 matt
83 * Added variable Current_seg_depth for detail level optimization
85 * Revision 1.31 1994/11/09 19:57:31 john
86 * Added texture rle caching.
88 * Revision 1.30 1994/11/09 19:54:48 mike
89 * Call flat shader if Tmap_flat_flag set.
91 * Revision 1.29 1994/11/02 21:33:31 john
92 * Added Burger Bill's optimization, ie.. 2 muls per 8 pixels.
94 * Revision 1.28 1994/11/02 11:32:16 john
95 * Added code for c callable inner loop and code to
96 * test dividing out z0.
98 * Revision 1.27 1994/10/28 20:54:32 matt
99 * Added error checking
101 * Revision 1.26 1994/10/25 11:20:20 mike
102 * fix bug in lighting overflow checking for one scanline tall linear texture maps.
104 * Revision 1.25 1994/08/03 15:40:33 mike
105 * Prevent divide overflows, decrease occurrence of precision-caused glitches.
107 * Revision 1.24 1994/07/27 09:31:16 mike
108 * Fix concave texture map problem, decrease occurrence of unimportant int 3.
110 * Revision 1.23 1994/06/17 12:23:31 mike
111 * Support non-lighted texture maps.
113 * Revision 1.22 1994/06/11 08:10:24 mike
114 * Fix mysterious hang bug, lighting value was out of range.
116 * Revision 1.21 1994/06/09 16:10:16 mike
117 * Change SC2000 from constant to variable.
126 static char rcsid[] = "$Id: ntmap.c,v 1.8 2003-03-19 19:21:34 btb Exp $";
132 #define HEADLIGHT_LIGHTING 0
135 #define PERSPECTIVE 1
147 #include "scanline.h"
150 #define EDITOR_TMAP 1 //if in, include extra stuff
153 #define F15_5 (F1_0*15 + F0_5)
155 // Temporary texture map, interface from Matt's 3d system to Mike's texture mapper.
158 grs_bitmap Texmap_ptrs[NUM_TMAPS];
159 grs_bitmap Texmap4_ptrs[NUM_TMAPS];
161 fix Range_max=0; // debug, kill me
163 int Interpolation_method=0; // 0 = choose best method
164 int Lighting_on=1; // initialize to no lighting
165 int Tmap_flat_flag = 0; // 1 = render texture maps as flat shaded polygons.
166 int Current_seg_depth; // HACK INTERFACE: how far away the current segment (& thus texture) is
167 int Max_perspective_depth;
168 int Max_linear_depth;
171 extern int Window_clip_left, Window_clip_bot, Window_clip_right, Window_clip_top;
173 // These variables are the interface to assembler. They get set for each texture map, which is a real waste of time.
174 // They should be set only when they change, which is generally when the window bounds change. And, even still, it's
175 // a pretty bad interface.
176 int bytes_per_row=-1;
177 unsigned char *write_buffer;
185 #define MAX_Y_POINTERS 1024
187 int y_pointers[MAX_Y_POINTERS];
189 fix fix_recip[FIX_RECIP_TABLE_SIZE];
191 int Lighting_enabled;
192 int Fix_recip_table_computed=0;
194 fix fx_l, fx_u, fx_v, fx_z, fx_du_dx, fx_dv_dx, fx_dz_dx, fx_dl_dx;
195 int fx_xleft, fx_xright, fx_y;
196 unsigned char * pixptr;
198 int Transparency_on = 0;
199 int dither_intensity_lighting = 0;
201 ubyte * tmap_flat_cthru_table;
202 ubyte tmap_flat_color;
203 ubyte tmap_flat_shade_value;
207 // -------------------------------------------------------------------------------------
208 void init_fix_recip_table(void)
214 for (i=1; i<FIX_RECIP_TABLE_SIZE; i++)
215 fix_recip[i] = F1_0/i;
217 Fix_recip_table_computed = 1;
220 // -------------------------------------------------------------------------------------
221 // Initialize interface variables to assembler.
222 // These things used to be constants. This routine is now (10/6/93) getting called for
223 // every texture map. It should get called whenever the window changes, or, preferably,
224 // not at all. I'm pretty sure these variables are only being used for range checking.
225 void init_interface_vars_to_assembler(void)
229 bp = &grd_curcanv->cv_bitmap;
232 Assert(bp->bm_data!=NULL);
233 Assert(bp->bm_h <= MAX_Y_POINTERS);
235 // If bytes_per_row has changed, create new table of pointers.
236 if (bytes_per_row != (int) bp->bm_rowsize) {
239 bytes_per_row = (int) bp->bm_rowsize;
242 for (i=0; i<MAX_Y_POINTERS; i++) {
243 y_pointers[i] = y_val;
244 y_val += bytes_per_row;
248 write_buffer = (unsigned char *) bp->bm_data;
251 window_right = (int) bp->bm_w-1;
253 window_bottom = (int) bp->bm_h-1;
255 Window_clip_left = window_left;
256 Window_clip_right = window_right;
257 Window_clip_top = window_top;
258 Window_clip_bot = window_bottom;
260 window_width = bp->bm_w;
261 window_height = bp->bm_h;
263 if (!Fix_recip_table_computed)
264 init_fix_recip_table();
267 // -------------------------------------------------------------------------------------
269 extern g3ds_tmap Tmap1;
271 // -------------------------------------------------------------------------------------
272 // Returns number preceding val modulo modulus.
275 int prevmod(int val,int modulus)
281 // return (val + modulus - 1) % modulus;
285 // Returns number succeeding val modulo modulus.
288 int succmod(int val,int modulus)
295 // return (val + 1) % modulus;
298 // -------------------------------------------------------------------------------------
299 // Select topmost vertex (minimum y coordinate) and bottommost (maximum y coordinate) in
300 // texture map. If either is part of a horizontal edge, then select leftmost vertex for
301 // top, rightmost vertex for bottom.
302 // Important: Vertex is selected with integer precision. So, if there are vertices at
303 // (0.0,0.7) and (0.5,0.3), the first vertex is selected, because they y coordinates are
304 // considered the same, so the smaller x is favored.
306 // nv number of vertices
307 // v3d pointer to 3d vertices containing u,v,x2d,y2d coordinates
311 // -------------------------------------------------------------------------------------
312 void compute_y_bounds(g3ds_tmap *t, int *vlt, int *vlb, int *vrt, int *vrb,int *bottom_y_ind)
320 // Scan all vertices, set min_y_ind to vertex with smallest y coordinate.
321 min_y = f2i(t->verts[0].y2d);
324 min_x = f2i(t->verts[0].x2d);
327 for (i=1; i<t->nv; i++) {
328 if (f2i(t->verts[i].y2d) < min_y) {
329 min_y = f2i(t->verts[i].y2d);
331 min_x = f2i(t->verts[i].x2d);
332 } else if (f2i(t->verts[i].y2d) == min_y) {
333 if (f2i(t->verts[i].x2d) < min_x) {
335 min_x = f2i(t->verts[i].x2d);
338 if (f2i(t->verts[i].y2d) > max_y) {
339 max_y = f2i(t->verts[i].y2d);
344 //--removed mk, 11/27/94-- // Check for a non-upright-hourglass polygon and fix, if necessary, by bashing a y coordinate.
345 //--removed mk, 11/27/94-- // min_y_ind = index of minimum y coordinate, *bottom_y_ind = index of maximum y coordinate
346 //--removed mk, 11/27/94--{
347 //--removed mk, 11/27/94-- int max_temp, min_temp;
348 //--removed mk, 11/27/94--
349 //--removed mk, 11/27/94-- max_temp = *bottom_y_ind;
350 //--removed mk, 11/27/94-- if (*bottom_y_ind < min_y_ind)
351 //--removed mk, 11/27/94-- max_temp += t->nv;
352 //--removed mk, 11/27/94--
353 //--removed mk, 11/27/94-- for (i=min_y_ind; i<max_temp; i++) {
354 //--removed mk, 11/27/94-- if (f2i(t->verts[i%t->nv].y2d) > f2i(t->verts[(i+1)%t->nv].y2d)) {
355 //--removed mk, 11/27/94-- Int3();
356 //--removed mk, 11/27/94-- t->verts[(i+1)%t->nv].y2d = t->verts[i%t->nv].y2d;
357 //--removed mk, 11/27/94-- }
358 //--removed mk, 11/27/94-- }
359 //--removed mk, 11/27/94--
360 //--removed mk, 11/27/94-- min_temp = min_y_ind;
361 //--removed mk, 11/27/94-- if (min_y_ind < *bottom_y_ind)
362 //--removed mk, 11/27/94-- min_temp += t->nv;
363 //--removed mk, 11/27/94--
364 //--removed mk, 11/27/94-- for (i=*bottom_y_ind; i<min_temp; i++) {
365 //--removed mk, 11/27/94-- if (f2i(t->verts[i%t->nv].y2d) < f2i(t->verts[(i+1)%t->nv].y2d)) {
366 //--removed mk, 11/27/94-- Int3();
367 //--removed mk, 11/27/94-- t->verts[(i+1)%t->nv].y2d = t->verts[i%t->nv].y2d;
368 //--removed mk, 11/27/94-- }
369 //--removed mk, 11/27/94-- }
370 //--removed mk, 11/27/94--}
372 // Set "vertex left top", etc. based on vertex with topmost y coordinate
375 *vlb = prevmod(*vlt,t->nv);
376 *vrb = succmod(*vrt,t->nv);
378 // If right edge is horizontal, then advance along polygon bound until it no longer is or until all
379 // vertices have been examined.
380 // (Left edge cannot be horizontal, because *vlt is set to leftmost point with highest y coordinate.)
384 while (f2i(t->verts[*vrt].y2d) == f2i(t->verts[*vrb].y2d)) {
385 if (succmod(*vrt,t->nv) == original_vrt) {
388 *vrt = succmod(*vrt,t->nv);
389 *vrb = succmod(*vrt,t->nv);
393 // -------------------------------------------------------------------------------------
394 // Returns dx/dy given two vertices.
395 // If dy == 0, returns 0.0
396 // -------------------------------------------------------------------------------------
397 //--fix compute_dx_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex)
401 //-- // compute delta x with respect to y for any edge
402 //-- dy = f2i(t->verts[bottom_vertex].y2d - t->verts[top_vertex].y2d) + 1;
404 //-- return (t->verts[bottom_vertex].x2d - t->verts[top_vertex].x2d) / dy;
410 fix compute_du_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
412 return fixmul(t->verts[bottom_vertex].u - t->verts[top_vertex].u, recip_dy);
416 fix compute_dv_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
418 return fixmul(t->verts[bottom_vertex].v - t->verts[top_vertex].v, recip_dy);
421 fix compute_dl_dy_lin(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
423 return fixmul(t->verts[bottom_vertex].l - t->verts[top_vertex].l, recip_dy);
427 fix compute_dx_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
429 return fixmul(t->verts[bottom_vertex].x2d - t->verts[top_vertex].x2d, recip_dy);
432 fix compute_du_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
434 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);
438 fix compute_dv_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
440 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);
444 fix compute_dz_dy(g3ds_tmap *t, int top_vertex,int bottom_vertex, fix recip_dy)
446 return fixmul(t->verts[bottom_vertex].z - t->verts[top_vertex].z, recip_dy);
449 int Skip_short_flag=0;
451 // -------------------------------------------------------------------------------------
452 // Texture map current scanline in perspective.
453 // -------------------------------------------------------------------------------------
454 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)
458 fx_xright = f2i(xright);
459 //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?
460 if (fx_xright < Window_clip_left)
462 fx_xleft = f2i(xleft);
463 if (fx_xleft > Window_clip_right)
467 dx = fx_xright - fx_xleft;
468 if ((dx < 0) || (xright < 0) || (xleft > xright)) // the (xleft > xright) term is not redundant with (dx < 0) because dx is computed using integers
471 // setup to call assembler scanline renderer
472 if (dx < FIX_RECIP_TABLE_SIZE)
473 recip_dx = fix_recip[dx];
481 fx_du_dx = fixmul(uright - uleft,recip_dx);
482 fx_dv_dx = fixmul(vright - vleft,recip_dx);
483 fx_dz_dx = fixmul(zright - zleft,recip_dx);
485 pixptr = srcb->bm_data;
487 switch (Lighting_enabled) {
489 //added 05/17/99 Matt Mueller - prevent writing before the buffer
490 if ((fx_y == 0) && (fx_xleft < 0))
493 if (fx_xright > Window_clip_right)
494 fx_xright = Window_clip_right;
496 cur_tmap_scanline_per();
501 if (lleft < 0) lleft = 0;
502 if (lright < 0) lright = 0;
503 if (lleft > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2)) lleft = (NUM_LIGHTING_LEVELS*F1_0-F1_0/2);
504 if (lright > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2)) lright = (NUM_LIGHTING_LEVELS*F1_0-F1_0/2);
507 fx_dl_dx = fixmul(lright - lleft,recip_dx);
509 // This is a pretty ugly hack to prevent lighting overflows.
510 mul_thing = dx * fx_dl_dx;
511 if (lleft + mul_thing < 0)
513 else if (lleft + mul_thing > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2))
516 //added 05/17/99 Matt Mueller - prevent writing before the buffer
517 if ((fx_y == 0) && (fx_xleft < 0))
520 if (fx_xright > Window_clip_right)
521 fx_xright = Window_clip_right;
523 cur_tmap_scanline_per();
528 fx_xright = f2i(xright);
529 fx_xleft = f2i(xleft);
532 cur_tmap_scanline_flat();
534 Int3(); // Illegal, called an editor only routine!
541 int Do_vertical_scan=0;
545 // -------------------------------------------------------------------------------------
546 // Render a texture map with lighting using perspective interpolation in inner and outer loops.
547 // -------------------------------------------------------------------------------------
548 void ntexture_map_lighted(grs_bitmap *srcb, g3ds_tmap *t)
550 int vlt,vrt,vlb,vrb; // vertex left top, vertex right top, vertex left bottom, vertex right bottom
552 fix dx_dy_left,dx_dy_right;
553 fix du_dy_left,du_dy_right;
554 fix dv_dy_left,dv_dy_right;
555 fix dz_dy_left,dz_dy_right;
556 fix dl_dy_left,dl_dy_right;
557 fix recip_dyl, recip_dyr;
559 fix xleft,xright,uleft,vleft,uright,vright,zleft,zright,lleft,lright;
560 int next_break_left, next_break_right;
564 //remove stupid warnings in compile
572 // Determine top and bottom y coords.
573 compute_y_bounds(t,&vlt,&vlb,&vrt,&vrb,&max_y_vertex);
575 // Set top and bottom (of entire texture map) y coordinates.
576 topy = f2i(v3d[vlt].y2d);
577 boty = f2i(v3d[max_y_vertex].y2d);
578 if (topy > Window_clip_bot)
580 if (boty > Window_clip_bot)
581 boty = Window_clip_bot;
583 // Set amount to change x coordinate for each advance to next scanline.
584 dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
585 if (dy < FIX_RECIP_TABLE_SIZE)
586 recip_dyl = fix_recip[dy];
590 dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dyl);
591 du_dy_left = compute_du_dy(t,vlt,vlb, recip_dyl);
592 dv_dy_left = compute_dv_dy(t,vlt,vlb, recip_dyl);
593 dz_dy_left = compute_dz_dy(t,vlt,vlb, recip_dyl);
595 dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
596 if (dy < FIX_RECIP_TABLE_SIZE)
597 recip_dyr = fix_recip[dy];
601 du_dy_right = compute_du_dy(t,vrt,vrb, recip_dyr);
602 dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dyr);
603 dv_dy_right = compute_dv_dy(t,vrt,vrb, recip_dyr);
604 dz_dy_right = compute_dz_dy(t,vrt,vrb, recip_dyr);
606 if (Lighting_enabled) {
607 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dyl);
608 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dyr);
614 // Set initial values for x, u, v
615 xleft = v3d[vlt].x2d;
616 xright = v3d[vrt].x2d;
621 uleft = fixmul(v3d[vlt].u,zleft);
622 uright = fixmul(v3d[vrt].u,zright);
623 vleft = fixmul(v3d[vlt].v,zleft);
624 vright = fixmul(v3d[vrt].v,zright);
626 // scan all rows in texture map from top through first break.
627 next_break_left = f2i(v3d[vlb].y2d);
628 next_break_right = f2i(v3d[vrb].y2d);
630 for (y = topy; y < boty; y++) {
632 // See if we have reached the end of the current left edge, and if so, set
633 // new values for dx_dy and x,u,v
634 if (y == next_break_left) {
637 // Handle problem of double points. Search until y coord is different. Cannot get
638 // hung in an infinite loop because we know there is a vertex with a lower y coordinate
639 // because in the for loop, we don't scan all spanlines.
640 while (y == f2i(v3d[vlb].y2d)) {
642 vlb = prevmod(vlb,t->nv);
644 next_break_left = f2i(v3d[vlb].y2d);
646 dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
647 if (dy < FIX_RECIP_TABLE_SIZE)
648 recip_dy = fix_recip[dy];
652 dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
654 xleft = v3d[vlt].x2d;
656 uleft = fixmul(v3d[vlt].u,zleft);
657 vleft = fixmul(v3d[vlt].v,zleft);
660 du_dy_left = compute_du_dy(t,vlt,vlb, recip_dy);
661 dv_dy_left = compute_dv_dy(t,vlt,vlb, recip_dy);
662 dz_dy_left = compute_dz_dy(t,vlt,vlb, recip_dy);
664 if (Lighting_enabled) {
665 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dy);
670 // See if we have reached the end of the current left edge, and if so, set
671 // new values for dx_dy and x. Not necessary to set new values for u,v.
672 if (y == next_break_right) {
675 while (y == f2i(v3d[vrb].y2d)) {
677 vrb = succmod(vrb,t->nv);
680 next_break_right = f2i(v3d[vrb].y2d);
682 dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
683 if (dy < FIX_RECIP_TABLE_SIZE)
684 recip_dy = fix_recip[dy];
688 dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
690 xright = v3d[vrt].x2d;
692 uright = fixmul(v3d[vrt].u,zright);
693 vright = fixmul(v3d[vrt].v,zright);
695 du_dy_right = compute_du_dy(t,vrt,vrb, recip_dy);
696 dv_dy_right = compute_dv_dy(t,vrt,vrb, recip_dy);
697 dz_dy_right = compute_dz_dy(t,vrt,vrb, recip_dy);
699 if (Lighting_enabled) {
700 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dy);
705 if (Lighting_enabled) {
706 if (y >= Window_clip_top)
707 ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
709 lright += dl_dy_right;
711 if (y >= Window_clip_top)
712 ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
717 uright += du_dy_right;
718 vright += dv_dy_right;
721 xright += dx_dy_right;
724 zright += dz_dy_right;
728 // We can get lleft or lright out of bounds here because we compute dl_dy using fixed point values,
729 // but we plot an integer number of scanlines, therefore doing an integer number of additions of the delta.
732 // mprintf(0, "[%i %i %i] ", y, f2i(xleft), f2i(xright));
734 ntmap_scanline_lighted(srcb,y,xleft,xright,uleft,uright,vleft,vright,zleft,zright,lleft,lright);
738 // -------------------------------------------------------------------------------------
739 // Texture map current scanline using linear interpolation.
740 // -------------------------------------------------------------------------------------
741 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)
746 fix du_dx,dv_dx,dl_dx;
752 dx = f2i(xright) - f2i(xleft);
753 if ((dx < 0) || (xright < 0) || (xleft > xright)) // the (xleft > xright) term is not redundant with (dx < 0) because dx is computed using integers
756 // setup to call assembler scanline renderer
757 if (dx < FIX_RECIP_TABLE_SIZE)
758 recip_dx = fix_recip[dx];
762 du_dx = fixmul(uright - uleft,recip_dx);
763 dv_dx = fixmul(vright - vleft,recip_dx);
770 fx_xright = f2i(xright);
771 fx_xleft = f2i(xleft);
772 pixptr = srcb->bm_data;
774 switch (Lighting_enabled) {
776 //added 07/11/99 adb - prevent writing before the buffer
781 cur_tmap_scanline_lin_nolight();
789 if (lleft > MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS)
790 lleft = MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS;
791 if (lright > MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS)
792 lright = MAX_LIGHTING_VALUE*NUM_LIGHTING_LEVELS;
794 //added 07/11/99 adb - prevent writing before the buffer
803 fx_dl_dx = fixmul(lright - lleft,recip_dx);
805 // This is a pretty ugly hack to prevent lighting overflows.
806 mul_thing = dx * fx_dl_dx;
807 if (lleft + mul_thing < 0)
809 else if (lleft + mul_thing > (NUM_LIGHTING_LEVELS*F1_0-F1_0/2))
814 dl_dx = fixmul(lright - lleft,recip_dx);
816 cur_tmap_scanline_lin();
820 fx_xright = f2i(xright);
821 fx_xleft = f2i(xleft);
823 cur_tmap_scanline_flat();
825 Int3(); // Illegal, called an editor only routine!
831 // -------------------------------------------------------------------------------------
832 // Render a texture map with lighting using perspective interpolation in inner and outer loops.
833 // -------------------------------------------------------------------------------------
834 void ntexture_map_lighted_linear(grs_bitmap *srcb, g3ds_tmap *t)
836 int vlt,vrt,vlb,vrb; // vertex left top, vertex right top, vertex left bottom, vertex right bottom
838 fix dx_dy_left,dx_dy_right;
839 fix du_dy_left,du_dy_right;
840 fix dv_dy_left,dv_dy_right;
841 fix dl_dy_left,dl_dy_right;
843 fix xleft,xright,uleft,vleft,uright,vright,lleft,lright;
844 int next_break_left, next_break_right;
845 fix recip_dyl, recip_dyr;
849 //remove stupid warnings in compile
857 // Determine top and bottom y coords.
858 compute_y_bounds(t,&vlt,&vlb,&vrt,&vrb,&max_y_vertex);
860 // Set top and bottom (of entire texture map) y coordinates.
861 topy = f2i(v3d[vlt].y2d);
862 boty = f2i(v3d[max_y_vertex].y2d);
864 if (topy > Window_clip_bot)
866 if (boty > Window_clip_bot)
867 boty = Window_clip_bot;
869 dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
870 if (dy < FIX_RECIP_TABLE_SIZE)
871 recip_dyl = fix_recip[dy];
875 dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
876 if (dy < FIX_RECIP_TABLE_SIZE)
877 recip_dyr = fix_recip[dy];
881 // Set amount to change x coordinate for each advance to next scanline.
882 dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dyl);
883 dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dyr);
885 du_dy_left = compute_du_dy_lin(t,vlt,vlb, recip_dyl);
886 du_dy_right = compute_du_dy_lin(t,vrt,vrb, recip_dyr);
888 dv_dy_left = compute_dv_dy_lin(t,vlt,vlb, recip_dyl);
889 dv_dy_right = compute_dv_dy_lin(t,vrt,vrb, recip_dyr);
891 if (Lighting_enabled) {
892 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dyl);
893 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dyr);
899 // Set initial values for x, u, v
900 xleft = v3d[vlt].x2d;
901 xright = v3d[vrt].x2d;
908 // scan all rows in texture map from top through first break.
909 next_break_left = f2i(v3d[vlb].y2d);
910 next_break_right = f2i(v3d[vrb].y2d);
912 for (y = topy; y < boty; y++) {
914 // See if we have reached the end of the current left edge, and if so, set
915 // new values for dx_dy and x,u,v
916 if (y == next_break_left) {
919 // Handle problem of double points. Search until y coord is different. Cannot get
920 // hung in an infinite loop because we know there is a vertex with a lower y coordinate
921 // because in the for loop, we don't scan all spanlines.
922 while (y == f2i(v3d[vlb].y2d)) {
924 vlb = prevmod(vlb,t->nv);
926 next_break_left = f2i(v3d[vlb].y2d);
928 dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
929 if (dy < FIX_RECIP_TABLE_SIZE)
930 recip_dy = fix_recip[dy];
934 dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
936 xleft = v3d[vlt].x2d;
941 du_dy_left = compute_du_dy_lin(t,vlt,vlb, recip_dy);
942 dv_dy_left = compute_dv_dy_lin(t,vlt,vlb, recip_dy);
944 if (Lighting_enabled) {
945 dl_dy_left = compute_dl_dy_lin(t,vlt,vlb, recip_dy);
950 // See if we have reached the end of the current left edge, and if so, set
951 // new values for dx_dy and x. Not necessary to set new values for u,v.
952 if (y == next_break_right) {
955 while (y == f2i(v3d[vrb].y2d)) {
957 vrb = succmod(vrb,t->nv);
960 dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
961 if (dy < FIX_RECIP_TABLE_SIZE)
962 recip_dy = fix_recip[dy];
966 next_break_right = f2i(v3d[vrb].y2d);
967 dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
969 xright = v3d[vrt].x2d;
973 du_dy_right = compute_du_dy_lin(t,vrt,vrb, recip_dy);
974 dv_dy_right = compute_dv_dy_lin(t,vrt,vrb, recip_dy);
976 if (Lighting_enabled) {
977 dl_dy_right = compute_dl_dy_lin(t,vrt,vrb, recip_dy);
982 if (Lighting_enabled) {
983 ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
985 lright += dl_dy_right;
987 ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
992 uright += du_dy_right;
993 vright += dv_dy_right;
996 xright += dx_dy_right;
1000 // We can get lleft or lright out of bounds here because we compute dl_dy using fixed point values,
1001 // but we plot an integer number of scanlines, therefore doing an integer number of additions of the delta.
1003 ntmap_scanline_lighted_linear(srcb,y,xleft,xright,uleft,uright,vleft,vright,lleft,lright);
1006 // fix DivNum = F1_0*12;
1008 extern void draw_tmap_flat(grs_bitmap *bp,int nverts,g3s_point **vertbuf);
1010 // -------------------------------------------------------------------------------------
1011 // Interface from Matt's data structures to Mike's texture mapper.
1012 // -------------------------------------------------------------------------------------
1013 void draw_tmap(grs_bitmap *bp,int nverts,g3s_point **vertbuf)
1017 // These variables are used in system which renders texture maps which lie on one scanline as a line.
1018 // fix div_numerator;
1019 int lighting_on_save = Lighting_on;
1021 Assert(nverts <= MAX_TMAP_VERTS);
1024 #ifdef USE_MULT_CODE
1025 if ( !divide_table_filled ) fill_divide_table();
1028 // -- now called from g3_start_frame -- init_interface_vars_to_assembler();
1030 // If no transparency and seg depth is large, render as flat shaded.
1031 if ((Current_seg_depth > Max_linear_depth) && ((bp->bm_flags & 3) == 0)) {
1032 draw_tmap_flat(bp, nverts, vertbuf);
1036 if ( bp->bm_flags & BM_FLAG_RLE )
1037 bp = rle_expand_texture( bp ); // Expand if rle'd
1039 Transparency_on = bp->bm_flags & BM_FLAG_TRANSPARENT;
1040 if (bp->bm_flags & BM_FLAG_NO_LIGHTING)
1044 // Setup texture map in Tmap1
1045 Tmap1.nv = nverts; // Initialize number of vertices
1047 // div_numerator = DivNum; //f1_0*3;
1049 for (i=0; i<nverts; i++) {
1050 g3ds_vertex *tvp = &Tmap1.verts[i];
1051 g3s_point *vp = vertbuf[i];
1053 tvp->x2d = vp->p3_sx;
1054 tvp->y2d = vp->p3_sy;
1056 // Check for overflow on fixdiv. Will overflow on vp->z <= something small. Allow only as low as 256.
1057 if (vp->p3_z < 256) {
1059 // Int3(); // we would overflow if we divided!
1062 tvp->z = fixdiv(F1_0*12, vp->p3_z);
1063 tvp->u = vp->p3_u << 6; //* bp->bm_w;
1064 tvp->v = vp->p3_v << 6; //* bp->bm_h;
1066 Assert(Lighting_on < 3);
1069 tvp->l = vp->p3_l * NUM_LIGHTING_LEVELS;
1073 Lighting_enabled = Lighting_on;
1075 // Now, call my texture mapper.
1077 switch (Interpolation_method) { // 0 = choose, 1 = linear, 2 = /8 perspective, 3 = full perspective
1078 case 0: // choose best interpolation
1080 if (Current_seg_depth > Max_perspective_depth)
1081 ntexture_map_lighted_linear(bp, &Tmap1);
1083 ntexture_map_lighted(bp, &Tmap1);
1085 case 1: // linear interpolation
1087 ntexture_map_lighted_linear(bp, &Tmap1);
1089 case 2: // perspective every 8th pixel interpolation
1091 ntexture_map_lighted(bp, &Tmap1);
1093 case 3: // perspective every pixel interpolation
1094 per2_flag = 0; // this hack means do divide every pixel
1095 ntexture_map_lighted(bp, &Tmap1);
1098 Assert(0); // Illegal value for Interpolation_method, must be 0,1,2,3
1101 switch (Interpolation_method) { // 0 = choose, 1 = linear, 2 = /8 perspective, 3 = full perspective
1102 case 0: // choose best interpolation
1104 if (Current_seg_depth > Max_perspective_depth)
1105 ntexture_map_lighted_linear(bp, &Tmap1);
1107 ntexture_map_lighted(bp, &Tmap1);
1109 case 1: // linear interpolation
1111 ntexture_map_lighted_linear(bp, &Tmap1);
1113 case 2: // perspective every 8th pixel interpolation
1115 ntexture_map_lighted(bp, &Tmap1);
1117 case 3: // perspective every pixel interpolation
1118 per2_flag = 0; // this hack means do divide every pixel
1119 ntexture_map_lighted(bp, &Tmap1);
1122 Assert(0); // Illegal value for Interpolation_method, must be 0,1,2,3
1126 Lighting_on = lighting_on_save;