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8 FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
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11 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
14 * $Source: /cvs/cvsroot/d2x/texmap/tmapflat.c,v $
15 * $Revision: 1.1.1.1 $
17 * $Date: 2001-01-19 03:30:16 $
19 * Flat shader derived from texture mapper (a little slow)
21 * $Log: not supported by cvs2svn $
22 * Revision 1.2 1999/10/07 21:03:29 donut
23 * OGL rendering of cloaked stuff
25 * Revision 1.1.1.1 1999/06/14 22:14:10 donut
26 * Import of d1x 1.37 source.
28 * Revision 1.13 1995/02/20 18:23:24 john
29 * Added new module for C versions of inner loops.
31 * Revision 1.12 1995/02/20 17:09:17 john
32 * Added code so that you can build the tmapper with no assembly!
34 * Revision 1.11 1994/11/30 00:58:01 mike
37 * Revision 1.10 1994/11/28 13:34:32 mike
40 * Revision 1.9 1994/11/19 15:21:46 mike
41 * rip out unused code.
43 * Revision 1.8 1994/11/12 16:41:41 mike
44 * *** empty log message ***
46 * Revision 1.7 1994/11/09 23:05:12 mike
47 * do lighting on texture maps which get flat shaded instead.
49 * Revision 1.6 1994/10/06 19:53:07 matt
50 * Added function that takes same parms as draw_tmap(), but renders flat
52 * Revision 1.5 1994/10/06 18:38:12 john
53 * Added the ability to fade a scanline by calling gr_upoly_tmap
54 * with Gr_scanline_darkening_level with a value < MAX_FADE_LEVELS.
56 * Revision 1.4 1994/05/25 18:46:32 matt
57 * Added gr_upoly_tmap_ylr(), which generates ylr's for a polygon
59 * Revision 1.3 1994/04/08 16:25:58 mike
60 * Comment out some includes (of header files)
61 * call init_interface_vars_to_assembler.
63 * Revision 1.2 1994/03/31 08:33:44 mike
64 * Fixup flat shading version of texture mapper (get it?)
65 * (Or maybe not, I admit to not testing my code...hahahah!)
67 * Revision 1.1 1993/09/08 17:29:10 mike
82 //#include "tmapext.h"
86 void (*scanline_func)(int,fix,fix);
88 // -------------------------------------------------------------------------------------
89 // Texture map current scanline.
90 // Uses globals Du_dx and Dv_dx to incrementally compute u,v coordinates
91 // -------------------------------------------------------------------------------------
92 void tmap_scanline_flat(int y, fix xleft, fix xright)
97 // setup to call assembler scanline renderer
100 fx_xleft = f2i(xleft);
101 fx_xright = f2i(xright);
103 if ( Gr_scanline_darkening_level >= GR_FADE_LEVELS )
105 c_tmap_scanline_flat();
107 asm_tmap_scanline_flat();
110 tmap_flat_shade_value = Gr_scanline_darkening_level;
112 c_tmap_scanline_shaded();
114 asm_tmap_scanline_shaded();
120 //--unused-- void tmap_scanline_shaded(int y, fix xleft, fix xright)
124 //--unused-- dx = xright - xleft;
126 //--unused-- // setup to call assembler scanline renderer
128 //--unused-- fx_y = y << 16;
129 //--unused-- fx_xleft = xleft;
130 //--unused-- fx_xright = xright;
132 //--unused-- asm_tmap_scanline_shaded();
136 // -------------------------------------------------------------------------------------
137 // Render a texture map.
138 // Linear in outer loop, linear in inner loop.
139 // -------------------------------------------------------------------------------------
140 void texture_map_flat(g3ds_tmap *t, int color)
142 int vlt,vrt,vlb,vrb; // vertex left top, vertex right top, vertex left bottom, vertex right bottom
144 fix dx_dy_left,dx_dy_right;
152 tmap_flat_color = color;
154 // Determine top and bottom y coords.
155 compute_y_bounds(t,&vlt,&vlb,&vrt,&vrb,&max_y_vertex);
157 // Set top and bottom (of entire texture map) y coordinates.
158 topy = f2i(v3d[vlt].y2d);
159 boty = f2i(v3d[max_y_vertex].y2d);
161 // Set amount to change x coordinate for each advance to next scanline.
162 dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
163 if (dy < FIX_RECIP_TABLE_SIZE)
164 recip_dy = fix_recip[dy];
168 dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
170 dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
171 if (dy < FIX_RECIP_TABLE_SIZE)
172 recip_dy = fix_recip[dy];
176 dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
178 // Set initial values for x, u, v
179 xleft = v3d[vlt].x2d;
180 xright = v3d[vrt].x2d;
182 // scan all rows in texture map from top through first break.
183 // @mk: Should we render the scanline for y==boty? This violates Matt's spec.
185 for (y = topy; y < boty; y++) {
187 // See if we have reached the end of the current left edge, and if so, set
188 // new values for dx_dy and x,u,v
189 if (y == f2i(v3d[vlb].y2d)) {
190 // Handle problem of double points. Search until y coord is different. Cannot get
191 // hung in an infinite loop because we know there is a vertex with a lower y coordinate
192 // because in the for loop, we don't scan all spanlines.
193 while (y == f2i(v3d[vlb].y2d)) {
195 vlb = prevmod(vlb,t->nv);
197 dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
198 if (dy < FIX_RECIP_TABLE_SIZE)
199 recip_dy = fix_recip[dy];
203 dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
205 xleft = v3d[vlt].x2d;
208 // See if we have reached the end of the current left edge, and if so, set
209 // new values for dx_dy and x. Not necessary to set new values for u,v.
210 if (y == f2i(v3d[vrb].y2d)) {
211 while (y == f2i(v3d[vrb].y2d)) {
213 vrb = succmod(vrb,t->nv);
216 dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
217 if (dy < FIX_RECIP_TABLE_SIZE)
218 recip_dy = fix_recip[dy];
222 dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
224 xright = v3d[vrt].x2d;
228 //tmap_scanline_flat(y, xleft, xright);
229 (*scanline_func)(y, xleft, xright);
232 xright += dx_dy_right;
235 //tmap_scanline_flat(y, xleft, xright);
236 (*scanline_func)(y, xleft, xright);
240 // -----------------------------------------------------------------------------------------
241 // This is the gr_upoly-like interface to the texture mapper which uses texture-mapper compatible
242 // (ie, avoids cracking) edge/delta computation.
243 void gr_upoly_tmap(int nverts, int *vert )
245 gr_upoly_tmap_ylr(nverts, vert, tmap_scanline_flat);
251 typedef struct pnt2d {
256 #pragma off (unreferenced) //bp not referenced
259 //this takes the same partms as draw_tmap, but draws a flat-shaded polygon
260 void draw_tmap_flat(grs_bitmap *bp,int nverts,g3s_point **vertbuf)
262 pnt2d points[MAX_TMAP_VERTS];
267 Assert(nverts < MAX_TMAP_VERTS);
269 average_light = vertbuf[0]->p3_l;
270 for (i=1; i<nverts; i++)
271 average_light += vertbuf[i]->p3_l;
274 average_light = f2i(average_light * NUM_LIGHTING_LEVELS/4);
276 average_light = f2i(average_light * NUM_LIGHTING_LEVELS/nverts);
278 if (average_light < 0)
280 else if (average_light > NUM_LIGHTING_LEVELS-1)
281 average_light = NUM_LIGHTING_LEVELS-1;
283 color = gr_fade_table[average_light*256 + bp->avg_color];
286 for (i=0;i<nverts;i++) {
287 points[i].x = vertbuf[i]->p3_sx;
288 points[i].y = vertbuf[i]->p3_sy;
291 gr_upoly_tmap(nverts,(int *) points);
295 #pragma on (unreferenced)
298 // -----------------------------------------------------------------------------------------
299 //This is like gr_upoly_tmap() but instead of drawing, it calls the specified
300 //function with ylr values
301 void gr_upoly_tmap_ylr(int nverts, int *vert, void (*ylr_func)(int,fix,fix) )
306 //--now called from g3_start_frame-- init_interface_vars_to_assembler();
310 for (i=0; i<nverts; i++) {
311 my_tmap.verts[i].x2d = *vert++;
312 my_tmap.verts[i].y2d = *vert++;
315 scanline_func = ylr_func;
317 texture_map_flat(&my_tmap, COLOR);