1 /*
2  * Mesa 3-D graphics library
3  *
4  * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included
14  * in all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22  * OTHER DEALINGS IN THE SOFTWARE.
23  *
24  *
25  * Authors:
26  *    Brian Paul Keith Whitwell <keithw@vmware.com>
27  */
28 
29 
30 #if IDX & LIGHT_TWOSIDE
31 #  define NR_SIDES 2
32 #else
33 #  define NR_SIDES 1
34 #endif
35 
36 
37 /* define TRACE to trace lighting code */
38 /* #define TRACE 1 */
39 
40 /*
41  * ctx is the current context
42  * VB is the vertex buffer
43  * stage is the lighting stage-private data
44  * input is the vector of eye or object-space vertex coordinates
45  */
TAG(light_rgba_spec)46 static void TAG(light_rgba_spec)( struct gl_context *ctx,
47 				  struct vertex_buffer *VB,
48 				  struct tnl_pipeline_stage *stage,
49 				  GLvector4f *input )
50 {
51    struct light_stage_data *store = LIGHT_STAGE_DATA(stage);
52    GLfloat (*base)[3] = ctx->Light._BaseColor;
53    GLfloat sumA[2];
54    GLuint j;
55 
56    const GLuint vstride = input->stride;
57    const GLfloat *vertex = (GLfloat *)input->data;
58    const GLuint nstride = VB->AttribPtr[_TNL_ATTRIB_NORMAL]->stride;
59    const GLfloat *normal = (GLfloat *)VB->AttribPtr[_TNL_ATTRIB_NORMAL]->data;
60 
61    GLfloat (*Fcolor)[4] = (GLfloat (*)[4]) store->LitColor[0].data;
62    GLfloat (*Fspec)[4] = (GLfloat (*)[4]) store->LitSecondary[0].data;
63 #if IDX & LIGHT_TWOSIDE
64    GLfloat (*Bcolor)[4] = (GLfloat (*)[4]) store->LitColor[1].data;
65    GLfloat (*Bspec)[4] = (GLfloat (*)[4]) store->LitSecondary[1].data;
66 #endif
67 
68    const GLuint nr = VB->Count;
69 
70 #ifdef TRACE
71    fprintf(stderr, "%s\n", __func__ );
72 #endif
73 
74    VB->AttribPtr[_TNL_ATTRIB_COLOR0] = &store->LitColor[0];
75    VB->AttribPtr[_TNL_ATTRIB_COLOR1] = &store->LitSecondary[0];
76    sumA[0] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
77 
78 #if IDX & LIGHT_TWOSIDE
79    VB->BackfaceColorPtr = &store->LitColor[1];
80    VB->BackfaceSecondaryColorPtr = &store->LitSecondary[1];
81    sumA[1] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
82 #endif
83 
84 
85    store->LitColor[0].stride = 16;
86    store->LitColor[1].stride = 16;
87 
88    for (j = 0; j < nr; j++,STRIDE_F(vertex,vstride),STRIDE_F(normal,nstride)) {
89       GLfloat sum[2][3], spec[2][3];
90       GLbitfield mask;
91 
92 #if IDX & LIGHT_MATERIAL
93       update_materials( ctx, store );
94       sumA[0] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
95 #if IDX & LIGHT_TWOSIDE
96       sumA[1] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
97 #endif
98 #endif
99 
100       COPY_3V(sum[0], base[0]);
101       ZERO_3V(spec[0]);
102 
103 #if IDX & LIGHT_TWOSIDE
104       COPY_3V(sum[1], base[1]);
105       ZERO_3V(spec[1]);
106 #endif
107 
108       /* Add contribution from each enabled light source */
109       mask = ctx->Light._EnabledLights;
110       while (mask) {
111          const int l = u_bit_scan(&mask);
112          struct gl_light *light = &ctx->Light.Light[l];
113 	 GLfloat n_dot_h;
114 	 GLfloat correction;
115 	 GLint side;
116 	 GLfloat contrib[3];
117 	 GLfloat attenuation;
118 	 GLfloat VP[3];          /* unit vector from vertex to light */
119 	 GLfloat n_dot_VP;       /* n dot VP */
120 	 GLfloat *h;
121 
122 	 /* compute VP and attenuation */
123 	 if (!(light->_Flags & LIGHT_POSITIONAL)) {
124 	    /* directional light */
125 	    COPY_3V(VP, light->_VP_inf_norm);
126 	    attenuation = light->_VP_inf_spot_attenuation;
127 	 }
128 	 else {
129 	    GLfloat d;     /* distance from vertex to light */
130 
131 	    SUB_3V(VP, light->_Position, vertex);
132 
133 	    d = (GLfloat) LEN_3FV( VP );
134 
135 	    if (d > 1e-6F) {
136 	       GLfloat invd = 1.0F / d;
137 	       SELF_SCALE_SCALAR_3V(VP, invd);
138 	    }
139 
140 	    attenuation = 1.0F / (light->ConstantAttenuation + d *
141 				  (light->LinearAttenuation + d *
142 				   light->QuadraticAttenuation));
143 
144 	    /* spotlight attenuation */
145 	    if (light->_Flags & LIGHT_SPOT) {
146 	       GLfloat PV_dot_dir = - DOT3(VP, light->_NormSpotDirection);
147 
148 	       if (PV_dot_dir<light->_CosCutoff) {
149 		  continue; /* this light makes no contribution */
150 	       }
151 	       else {
152                   GLfloat spot = powf(PV_dot_dir, light->SpotExponent);
153 		  attenuation *= spot;
154 	       }
155 	    }
156 	 }
157 
158 	 if (attenuation < 1e-3F)
159 	    continue;		/* this light makes no contribution */
160 
161 	 /* Compute dot product or normal and vector from V to light pos */
162 	 n_dot_VP = DOT3( normal, VP );
163 
164 	 /* Which side gets the diffuse & specular terms? */
165 	 if (n_dot_VP < 0.0F) {
166 	    ACC_SCALE_SCALAR_3V(sum[0], attenuation, light->_MatAmbient[0]);
167 #if IDX & LIGHT_TWOSIDE
168 	    side = 1;
169 	    correction = -1;
170 	    n_dot_VP = -n_dot_VP;
171 #else
172             continue;
173 #endif
174 	 }
175          else {
176 #if IDX & LIGHT_TWOSIDE
177             ACC_SCALE_SCALAR_3V( sum[1], attenuation, light->_MatAmbient[1]);
178 #endif
179 	    side = 0;
180 	    correction = 1;
181 	 }
182 
183 	 /* diffuse term */
184 	 COPY_3V(contrib, light->_MatAmbient[side]);
185 	 ACC_SCALE_SCALAR_3V(contrib, n_dot_VP, light->_MatDiffuse[side]);
186 	 ACC_SCALE_SCALAR_3V(sum[side], attenuation, contrib );
187 
188 	 /* specular term - cannibalize VP... */
189 	 if (ctx->Light.Model.LocalViewer) {
190 	    GLfloat v[3];
191 	    COPY_3V(v, vertex);
192 	    NORMALIZE_3FV(v);
193 	    SUB_3V(VP, VP, v);                /* h = VP + VPe */
194 	    h = VP;
195 	    NORMALIZE_3FV(h);
196 	 }
197 	 else if (light->_Flags & LIGHT_POSITIONAL) {
198 	    h = VP;
199 	    ACC_3V(h, ctx->_EyeZDir);
200 	    NORMALIZE_3FV(h);
201 	 }
202          else {
203 	    h = light->_h_inf_norm;
204 	 }
205 
206 	 n_dot_h = correction * DOT3(normal, h);
207 
208 	 if (n_dot_h > 0.0F) {
209 	    GLfloat spec_coef = lookup_shininess(ctx, side, n_dot_h);
210 	    if (spec_coef > 1.0e-10F) {
211 	       spec_coef *= attenuation;
212 	       ACC_SCALE_SCALAR_3V( spec[side], spec_coef,
213 				    light->_MatSpecular[side]);
214 	    }
215 	 }
216       } /*loop over lights*/
217 
218       COPY_3V( Fcolor[j], sum[0] );
219       COPY_3V( Fspec[j], spec[0] );
220       Fcolor[j][3] = sumA[0];
221 
222 #if IDX & LIGHT_TWOSIDE
223       COPY_3V( Bcolor[j], sum[1] );
224       COPY_3V( Bspec[j], spec[1] );
225       Bcolor[j][3] = sumA[1];
226 #endif
227    }
228 }
229 
230 
TAG(light_rgba)231 static void TAG(light_rgba)( struct gl_context *ctx,
232 			     struct vertex_buffer *VB,
233 			     struct tnl_pipeline_stage *stage,
234 			     GLvector4f *input )
235 {
236    struct light_stage_data *store = LIGHT_STAGE_DATA(stage);
237    GLuint j;
238 
239    GLfloat (*base)[3] = ctx->Light._BaseColor;
240    GLfloat sumA[2];
241 
242    const GLuint vstride = input->stride;
243    const GLfloat *vertex = (GLfloat *) input->data;
244    const GLuint nstride = VB->AttribPtr[_TNL_ATTRIB_NORMAL]->stride;
245    const GLfloat *normal = (GLfloat *)VB->AttribPtr[_TNL_ATTRIB_NORMAL]->data;
246 
247    GLfloat (*Fcolor)[4] = (GLfloat (*)[4]) store->LitColor[0].data;
248 #if IDX & LIGHT_TWOSIDE
249    GLfloat (*Bcolor)[4] = (GLfloat (*)[4]) store->LitColor[1].data;
250 #endif
251 
252    const GLuint nr = VB->Count;
253 
254 #ifdef TRACE
255    fprintf(stderr, "%s\n", __func__ );
256 #endif
257 
258    VB->AttribPtr[_TNL_ATTRIB_COLOR0] = &store->LitColor[0];
259    sumA[0] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
260 
261 #if IDX & LIGHT_TWOSIDE
262    VB->BackfaceColorPtr = &store->LitColor[1];
263    sumA[1] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
264 #endif
265 
266    store->LitColor[0].stride = 16;
267    store->LitColor[1].stride = 16;
268 
269    for (j = 0; j < nr; j++,STRIDE_F(vertex,vstride),STRIDE_F(normal,nstride)) {
270       GLfloat sum[2][3];
271       GLbitfield mask;
272 
273 #if IDX & LIGHT_MATERIAL
274       update_materials( ctx, store );
275       sumA[0] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
276 #if IDX & LIGHT_TWOSIDE
277       sumA[1] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
278 #endif
279 #endif
280 
281       COPY_3V(sum[0], base[0]);
282 
283 #if IDX & LIGHT_TWOSIDE
284       COPY_3V(sum[1], base[1]);
285 #endif
286 
287       /* Add contribution from each enabled light source */
288       mask = ctx->Light._EnabledLights;
289       while (mask) {
290          const int l = u_bit_scan(&mask);
291          struct gl_light *light = &ctx->Light.Light[l];
292 	 GLfloat n_dot_h;
293 	 GLfloat correction;
294 	 GLint side;
295 	 GLfloat contrib[3];
296 	 GLfloat attenuation;
297 	 GLfloat VP[3];          /* unit vector from vertex to light */
298 	 GLfloat n_dot_VP;       /* n dot VP */
299 	 GLfloat *h;
300 
301 	 /* compute VP and attenuation */
302 	 if (!(light->_Flags & LIGHT_POSITIONAL)) {
303 	    /* directional light */
304 	    COPY_3V(VP, light->_VP_inf_norm);
305 	    attenuation = light->_VP_inf_spot_attenuation;
306 	 }
307 	 else {
308 	    GLfloat d;     /* distance from vertex to light */
309 
310 	    SUB_3V(VP, light->_Position, vertex);
311 
312 	    d = (GLfloat) LEN_3FV( VP );
313 
314 	    if (d > 1e-6F) {
315 	       GLfloat invd = 1.0F / d;
316 	       SELF_SCALE_SCALAR_3V(VP, invd);
317 	    }
318 
319             attenuation = 1.0F / (light->ConstantAttenuation + d *
320                                   (light->LinearAttenuation + d *
321                                    light->QuadraticAttenuation));
322 
323 	    /* spotlight attenuation */
324 	    if (light->_Flags & LIGHT_SPOT) {
325 	       GLfloat PV_dot_dir = - DOT3(VP, light->_NormSpotDirection);
326 
327 	       if (PV_dot_dir<light->_CosCutoff) {
328 		  continue; /* this light makes no contribution */
329 	       }
330 	       else {
331                   GLfloat spot = powf(PV_dot_dir, light->SpotExponent);
332 		  attenuation *= spot;
333 	       }
334 	    }
335 	 }
336 
337 	 if (attenuation < 1e-3F)
338 	    continue;		/* this light makes no contribution */
339 
340 	 /* Compute dot product or normal and vector from V to light pos */
341 	 n_dot_VP = DOT3( normal, VP );
342 
343 	 /* which side are we lighting? */
344 	 if (n_dot_VP < 0.0F) {
345 	    ACC_SCALE_SCALAR_3V(sum[0], attenuation, light->_MatAmbient[0]);
346 #if IDX & LIGHT_TWOSIDE
347 	    side = 1;
348 	    correction = -1;
349 	    n_dot_VP = -n_dot_VP;
350 #else
351             continue;
352 #endif
353 	 }
354          else {
355 #if IDX & LIGHT_TWOSIDE
356             ACC_SCALE_SCALAR_3V( sum[1], attenuation, light->_MatAmbient[1]);
357 #endif
358 	    side = 0;
359 	    correction = 1;
360 	 }
361 
362 	 COPY_3V(contrib, light->_MatAmbient[side]);
363 
364 	 /* diffuse term */
365 	 ACC_SCALE_SCALAR_3V(contrib, n_dot_VP, light->_MatDiffuse[side]);
366 
367 	 /* specular term - cannibalize VP... */
368 	 {
369 	    if (ctx->Light.Model.LocalViewer) {
370 	       GLfloat v[3];
371 	       COPY_3V(v, vertex);
372 	       NORMALIZE_3FV(v);
373 	       SUB_3V(VP, VP, v);                /* h = VP + VPe */
374 	       h = VP;
375 	       NORMALIZE_3FV(h);
376 	    }
377 	    else if (light->_Flags & LIGHT_POSITIONAL) {
378 	       h = VP;
379 	       ACC_3V(h, ctx->_EyeZDir);
380 	       NORMALIZE_3FV(h);
381 	    }
382             else {
383 	       h = light->_h_inf_norm;
384 	    }
385 
386 	    n_dot_h = correction * DOT3(normal, h);
387 
388 	    if (n_dot_h > 0.0F) {
389 	       GLfloat spec_coef = lookup_shininess(ctx, side, n_dot_h);
390 	       ACC_SCALE_SCALAR_3V( contrib, spec_coef,
391 				    light->_MatSpecular[side]);
392 	    }
393 	 }
394 
395 	 ACC_SCALE_SCALAR_3V( sum[side], attenuation, contrib );
396       }
397 
398       COPY_3V( Fcolor[j], sum[0] );
399       Fcolor[j][3] = sumA[0];
400 
401 #if IDX & LIGHT_TWOSIDE
402       COPY_3V( Bcolor[j], sum[1] );
403       Bcolor[j][3] = sumA[1];
404 #endif
405    }
406 }
407 
408 
409 
410 
411 /* As below, but with just a single light.
412  */
TAG(light_fast_rgba_single)413 static void TAG(light_fast_rgba_single)( struct gl_context *ctx,
414 					 struct vertex_buffer *VB,
415 					 struct tnl_pipeline_stage *stage,
416 					 GLvector4f *input )
417 
418 {
419    struct light_stage_data *store = LIGHT_STAGE_DATA(stage);
420    const GLuint nstride = VB->AttribPtr[_TNL_ATTRIB_NORMAL]->stride;
421    const GLfloat *normal = (GLfloat *)VB->AttribPtr[_TNL_ATTRIB_NORMAL]->data;
422    GLfloat (*Fcolor)[4] = (GLfloat (*)[4]) store->LitColor[0].data;
423 #if IDX & LIGHT_TWOSIDE
424    GLfloat (*Bcolor)[4] = (GLfloat (*)[4]) store->LitColor[1].data;
425 #endif
426    const struct gl_light *light =
427       &ctx->Light.Light[ffs(ctx->Light._EnabledLights) - 1];
428    GLuint j = 0;
429    GLfloat base[2][4];
430 #if IDX & LIGHT_MATERIAL
431    const GLuint nr = VB->Count;
432 #else
433    const GLuint nr = VB->AttribPtr[_TNL_ATTRIB_NORMAL]->count;
434 #endif
435 
436 #ifdef TRACE
437    fprintf(stderr, "%s\n", __func__ );
438 #endif
439 
440    (void) input;		/* doesn't refer to Eye or Obj */
441 
442    VB->AttribPtr[_TNL_ATTRIB_COLOR0] = &store->LitColor[0];
443 #if IDX & LIGHT_TWOSIDE
444    VB->BackfaceColorPtr = &store->LitColor[1];
445 #endif
446 
447    if (nr > 1) {
448       store->LitColor[0].stride = 16;
449       store->LitColor[1].stride = 16;
450    }
451    else {
452       store->LitColor[0].stride = 0;
453       store->LitColor[1].stride = 0;
454    }
455 
456    for (j = 0; j < nr; j++, STRIDE_F(normal,nstride)) {
457 
458       GLfloat n_dot_VP;
459 
460 #if IDX & LIGHT_MATERIAL
461       update_materials( ctx, store );
462 #endif
463 
464       /* No attenuation, so incoporate _MatAmbient into base color.
465        */
466 #if !(IDX & LIGHT_MATERIAL)
467       if ( j == 0 )
468 #endif
469       {
470 	 COPY_3V(base[0], light->_MatAmbient[0]);
471 	 ACC_3V(base[0], ctx->Light._BaseColor[0] );
472 	 base[0][3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
473 
474 #if IDX & LIGHT_TWOSIDE
475          COPY_3V(base[1], light->_MatAmbient[1]);
476          ACC_3V(base[1], ctx->Light._BaseColor[1]);
477          base[1][3] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
478 #endif
479       }
480 
481       n_dot_VP = DOT3(normal, light->_VP_inf_norm);
482 
483       if (n_dot_VP < 0.0F) {
484 #if IDX & LIGHT_TWOSIDE
485          GLfloat n_dot_h = -DOT3(normal, light->_h_inf_norm);
486          GLfloat sum[3];
487          COPY_3V(sum, base[1]);
488          ACC_SCALE_SCALAR_3V(sum, -n_dot_VP, light->_MatDiffuse[1]);
489          if (n_dot_h > 0.0F) {
490             GLfloat spec = lookup_shininess(ctx, 1, n_dot_h);
491             ACC_SCALE_SCALAR_3V(sum, spec, light->_MatSpecular[1]);
492          }
493          COPY_3V(Bcolor[j], sum );
494          Bcolor[j][3] = base[1][3];
495 #endif
496 	 COPY_4FV(Fcolor[j], base[0]);
497       }
498       else {
499 	 GLfloat n_dot_h = DOT3(normal, light->_h_inf_norm);
500 	 GLfloat sum[3];
501 	 COPY_3V(sum, base[0]);
502 	 ACC_SCALE_SCALAR_3V(sum, n_dot_VP, light->_MatDiffuse[0]);
503 	 if (n_dot_h > 0.0F) {
504             GLfloat spec = lookup_shininess(ctx, 0, n_dot_h);
505 	    ACC_SCALE_SCALAR_3V(sum, spec, light->_MatSpecular[0]);
506 	 }
507 	 COPY_3V(Fcolor[j], sum );
508 	 Fcolor[j][3] = base[0][3];
509 #if IDX & LIGHT_TWOSIDE
510          COPY_4FV(Bcolor[j], base[1]);
511 #endif
512       }
513    }
514 }
515 
516 
517 /* Light infinite lights
518  */
TAG(light_fast_rgba)519 static void TAG(light_fast_rgba)( struct gl_context *ctx,
520 				  struct vertex_buffer *VB,
521 				  struct tnl_pipeline_stage *stage,
522 				  GLvector4f *input )
523 {
524    struct light_stage_data *store = LIGHT_STAGE_DATA(stage);
525    GLfloat sumA[2];
526    const GLuint nstride = VB->AttribPtr[_TNL_ATTRIB_NORMAL]->stride;
527    const GLfloat *normal = (GLfloat *)VB->AttribPtr[_TNL_ATTRIB_NORMAL]->data;
528    GLfloat (*Fcolor)[4] = (GLfloat (*)[4]) store->LitColor[0].data;
529 #if IDX & LIGHT_TWOSIDE
530    GLfloat (*Bcolor)[4] = (GLfloat (*)[4]) store->LitColor[1].data;
531 #endif
532    GLuint j = 0;
533 #if IDX & LIGHT_MATERIAL
534    const GLuint nr = VB->Count;
535 #else
536    const GLuint nr = VB->AttribPtr[_TNL_ATTRIB_NORMAL]->count;
537 #endif
538 
539 #ifdef TRACE
540    fprintf(stderr, "%s %d\n", __func__, nr );
541 #endif
542 
543    (void) input;
544 
545    sumA[0] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
546    sumA[1] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
547 
548    VB->AttribPtr[_TNL_ATTRIB_COLOR0] = &store->LitColor[0];
549 #if IDX & LIGHT_TWOSIDE
550    VB->BackfaceColorPtr = &store->LitColor[1];
551 #endif
552 
553    if (nr > 1) {
554       store->LitColor[0].stride = 16;
555       store->LitColor[1].stride = 16;
556    }
557    else {
558       store->LitColor[0].stride = 0;
559       store->LitColor[1].stride = 0;
560    }
561 
562    for (j = 0; j < nr; j++, STRIDE_F(normal,nstride)) {
563 
564       GLfloat sum[2][3];
565       GLbitfield mask;
566 
567 #if IDX & LIGHT_MATERIAL
568       update_materials( ctx, store );
569 
570       sumA[0] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
571 #if IDX & LIGHT_TWOSIDE
572       sumA[1] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
573 #endif
574 #endif
575 
576 
577       COPY_3V(sum[0], ctx->Light._BaseColor[0]);
578 #if IDX & LIGHT_TWOSIDE
579       COPY_3V(sum[1], ctx->Light._BaseColor[1]);
580 #endif
581 
582       mask = ctx->Light._EnabledLights;
583       while (mask) {
584          const int l = u_bit_scan(&mask);
585          const struct gl_light *light = &ctx->Light.Light[l];
586 	 GLfloat n_dot_h, n_dot_VP, spec;
587 
588 	 ACC_3V(sum[0], light->_MatAmbient[0]);
589 #if IDX & LIGHT_TWOSIDE
590          ACC_3V(sum[1], light->_MatAmbient[1]);
591 #endif
592 
593 	 n_dot_VP = DOT3(normal, light->_VP_inf_norm);
594 
595 	 if (n_dot_VP > 0.0F) {
596 	    ACC_SCALE_SCALAR_3V(sum[0], n_dot_VP, light->_MatDiffuse[0]);
597 	    n_dot_h = DOT3(normal, light->_h_inf_norm);
598 	    if (n_dot_h > 0.0F) {
599                spec = lookup_shininess(ctx, 0, n_dot_h);
600 	       ACC_SCALE_SCALAR_3V( sum[0], spec, light->_MatSpecular[0]);
601 	    }
602 	 }
603 #if IDX & LIGHT_TWOSIDE
604          else {
605 	    ACC_SCALE_SCALAR_3V(sum[1], -n_dot_VP, light->_MatDiffuse[1]);
606 	    n_dot_h = -DOT3(normal, light->_h_inf_norm);
607 	    if (n_dot_h > 0.0F) {
608                spec = lookup_shininess(ctx, 1, n_dot_h);
609 	       ACC_SCALE_SCALAR_3V( sum[1], spec, light->_MatSpecular[1]);
610 	    }
611 	 }
612 #endif
613       }
614 
615       COPY_3V( Fcolor[j], sum[0] );
616       Fcolor[j][3] = sumA[0];
617 
618 #if IDX & LIGHT_TWOSIDE
619       COPY_3V( Bcolor[j], sum[1] );
620       Bcolor[j][3] = sumA[1];
621 #endif
622    }
623 }
624 
625 
626 
627 
TAG(init_light_tab)628 static void TAG(init_light_tab)( void )
629 {
630    _tnl_light_tab[IDX] = TAG(light_rgba);
631    _tnl_light_fast_tab[IDX] = TAG(light_fast_rgba);
632    _tnl_light_fast_single_tab[IDX] = TAG(light_fast_rgba_single);
633    _tnl_light_spec_tab[IDX] = TAG(light_rgba_spec);
634 }
635 
636 
637 #undef TAG
638 #undef IDX
639 #undef NR_SIDES
640