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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.
14 * $Source: /cvs/cvsroot/d2x/texmap/tmapflat.c,v $
17 * $Date: 2001-01-31 14:04:46 $
19 * Flat shader derived from texture mapper (a little slow)
21 * $Log: not supported by cvs2svn $
22 * Revision 1.1.1.1 2001/01/19 03:30:16 bradleyb
25 * Revision 1.2 1999/10/07 21:03:29 donut
26 * OGL rendering of cloaked stuff
28 * Revision 1.1.1.1 1999/06/14 22:14:10 donut
29 * Import of d1x 1.37 source.
31 * Revision 1.13 1995/02/20 18:23:24 john
32 * Added new module for C versions of inner loops.
34 * Revision 1.12 1995/02/20 17:09:17 john
35 * Added code so that you can build the tmapper with no assembly!
37 * Revision 1.11 1994/11/30 00:58:01 mike
40 * Revision 1.10 1994/11/28 13:34:32 mike
43 * Revision 1.9 1994/11/19 15:21:46 mike
44 * rip out unused code.
46 * Revision 1.8 1994/11/12 16:41:41 mike
47 * *** empty log message ***
49 * Revision 1.7 1994/11/09 23:05:12 mike
50 * do lighting on texture maps which get flat shaded instead.
52 * Revision 1.6 1994/10/06 19:53:07 matt
53 * Added function that takes same parms as draw_tmap(), but renders flat
55 * Revision 1.5 1994/10/06 18:38:12 john
56 * Added the ability to fade a scanline by calling gr_upoly_tmap
57 * with Gr_scanline_darkening_level with a value < MAX_FADE_LEVELS.
59 * Revision 1.4 1994/05/25 18:46:32 matt
60 * Added gr_upoly_tmap_ylr(), which generates ylr's for a polygon
62 * Revision 1.3 1994/04/08 16:25:58 mike
63 * Comment out some includes (of header files)
64 * call init_interface_vars_to_assembler.
66 * Revision 1.2 1994/03/31 08:33:44 mike
67 * Fixup flat shading version of texture mapper (get it?)
68 * (Or maybe not, I admit to not testing my code...hahahah!)
70 * Revision 1.1 1993/09/08 17:29:10 mike
88 //#include "tmapext.h"
92 void (*scanline_func)(int,fix,fix);
94 // -------------------------------------------------------------------------------------
95 // Texture map current scanline.
96 // Uses globals Du_dx and Dv_dx to incrementally compute u,v coordinates
97 // -------------------------------------------------------------------------------------
98 void tmap_scanline_flat(int y, fix xleft, fix xright)
103 // setup to call assembler scanline renderer
106 fx_xleft = f2i(xleft);
107 fx_xright = f2i(xright);
109 if ( Gr_scanline_darkening_level >= GR_FADE_LEVELS )
111 c_tmap_scanline_flat();
113 asm_tmap_scanline_flat();
116 tmap_flat_shade_value = Gr_scanline_darkening_level;
118 c_tmap_scanline_shaded();
120 asm_tmap_scanline_shaded();
126 //--unused-- void tmap_scanline_shaded(int y, fix xleft, fix xright)
130 //--unused-- dx = xright - xleft;
132 //--unused-- // setup to call assembler scanline renderer
134 //--unused-- fx_y = y << 16;
135 //--unused-- fx_xleft = xleft;
136 //--unused-- fx_xright = xright;
138 //--unused-- asm_tmap_scanline_shaded();
142 // -------------------------------------------------------------------------------------
143 // Render a texture map.
144 // Linear in outer loop, linear in inner loop.
145 // -------------------------------------------------------------------------------------
146 void texture_map_flat(g3ds_tmap *t, int color)
148 int vlt,vrt,vlb,vrb; // vertex left top, vertex right top, vertex left bottom, vertex right bottom
150 fix dx_dy_left,dx_dy_right;
158 tmap_flat_color = color;
160 // Determine top and bottom y coords.
161 compute_y_bounds(t,&vlt,&vlb,&vrt,&vrb,&max_y_vertex);
163 // Set top and bottom (of entire texture map) y coordinates.
164 topy = f2i(v3d[vlt].y2d);
165 boty = f2i(v3d[max_y_vertex].y2d);
167 // Set amount to change x coordinate for each advance to next scanline.
168 dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
169 if (dy < FIX_RECIP_TABLE_SIZE)
170 recip_dy = fix_recip[dy];
174 dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
176 dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
177 if (dy < FIX_RECIP_TABLE_SIZE)
178 recip_dy = fix_recip[dy];
182 dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
184 // Set initial values for x, u, v
185 xleft = v3d[vlt].x2d;
186 xright = v3d[vrt].x2d;
188 // scan all rows in texture map from top through first break.
189 // @mk: Should we render the scanline for y==boty? This violates Matt's spec.
191 for (y = topy; y < boty; y++) {
193 // See if we have reached the end of the current left edge, and if so, set
194 // new values for dx_dy and x,u,v
195 if (y == f2i(v3d[vlb].y2d)) {
196 // Handle problem of double points. Search until y coord is different. Cannot get
197 // hung in an infinite loop because we know there is a vertex with a lower y coordinate
198 // because in the for loop, we don't scan all spanlines.
199 while (y == f2i(v3d[vlb].y2d)) {
201 vlb = prevmod(vlb,t->nv);
203 dy = f2i(t->verts[vlb].y2d) - f2i(t->verts[vlt].y2d);
204 if (dy < FIX_RECIP_TABLE_SIZE)
205 recip_dy = fix_recip[dy];
209 dx_dy_left = compute_dx_dy(t,vlt,vlb, recip_dy);
211 xleft = v3d[vlt].x2d;
214 // See if we have reached the end of the current left edge, and if so, set
215 // new values for dx_dy and x. Not necessary to set new values for u,v.
216 if (y == f2i(v3d[vrb].y2d)) {
217 while (y == f2i(v3d[vrb].y2d)) {
219 vrb = succmod(vrb,t->nv);
222 dy = f2i(t->verts[vrb].y2d) - f2i(t->verts[vrt].y2d);
223 if (dy < FIX_RECIP_TABLE_SIZE)
224 recip_dy = fix_recip[dy];
228 dx_dy_right = compute_dx_dy(t,vrt,vrb, recip_dy);
230 xright = v3d[vrt].x2d;
234 //tmap_scanline_flat(y, xleft, xright);
235 (*scanline_func)(y, xleft, xright);
238 xright += dx_dy_right;
241 //tmap_scanline_flat(y, xleft, xright);
242 (*scanline_func)(y, xleft, xright);
246 // -----------------------------------------------------------------------------------------
247 // This is the gr_upoly-like interface to the texture mapper which uses texture-mapper compatible
248 // (ie, avoids cracking) edge/delta computation.
249 void gr_upoly_tmap(int nverts, int *vert )
251 gr_upoly_tmap_ylr(nverts, vert, tmap_scanline_flat);
257 typedef struct pnt2d {
262 #pragma off (unreferenced) //bp not referenced
265 //this takes the same partms as draw_tmap, but draws a flat-shaded polygon
266 void draw_tmap_flat(grs_bitmap *bp,int nverts,g3s_point **vertbuf)
268 pnt2d points[MAX_TMAP_VERTS];
273 Assert(nverts < MAX_TMAP_VERTS);
275 average_light = vertbuf[0]->p3_l;
276 for (i=1; i<nverts; i++)
277 average_light += vertbuf[i]->p3_l;
280 average_light = f2i(average_light * NUM_LIGHTING_LEVELS/4);
282 average_light = f2i(average_light * NUM_LIGHTING_LEVELS/nverts);
284 if (average_light < 0)
286 else if (average_light > NUM_LIGHTING_LEVELS-1)
287 average_light = NUM_LIGHTING_LEVELS-1;
289 color = gr_fade_table[average_light*256 + bp->avg_color];
292 for (i=0;i<nverts;i++) {
293 points[i].x = vertbuf[i]->p3_sx;
294 points[i].y = vertbuf[i]->p3_sy;
297 gr_upoly_tmap(nverts,(int *) points);
301 #pragma on (unreferenced)
304 // -----------------------------------------------------------------------------------------
305 //This is like gr_upoly_tmap() but instead of drawing, it calls the specified
306 //function with ylr values
307 void gr_upoly_tmap_ylr(int nverts, int *vert, void (*ylr_func)(int,fix,fix) )
312 //--now called from g3_start_frame-- init_interface_vars_to_assembler();
316 for (i=0; i<nverts; i++) {
317 my_tmap.verts[i].x2d = *vert++;
318 my_tmap.verts[i].y2d = *vert++;
321 scanline_func = ylr_func;
323 texture_map_flat(&my_tmap, COLOR);