s_triangle.c revision 47b29f511a8e917c65536fde90397d54d2ad23d3
1/*
2 * Mesa 3-D graphics library
3 * Version:  6.3
4 *
5 * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26/*
27 * When the device driver doesn't implement triangle rasterization it
28 * can hook in _swrast_Triangle, which eventually calls one of these
29 * functions to draw triangles.
30 */
31
32#include "glheader.h"
33#include "context.h"
34#include "colormac.h"
35#include "imports.h"
36#include "macros.h"
37#include "texformat.h"
38#include "teximage.h"
39#include "texstate.h"
40
41#include "s_aatriangle.h"
42#include "s_context.h"
43#include "s_depth.h"
44#include "s_feedback.h"
45#include "s_span.h"
46#include "s_triangle.h"
47
48
49/*
50 * Just used for feedback mode.
51 */
52GLboolean
53_swrast_culltriangle( GLcontext *ctx,
54                      const SWvertex *v0,
55                      const SWvertex *v1,
56                      const SWvertex *v2 )
57{
58   GLfloat ex = v1->win[0] - v0->win[0];
59   GLfloat ey = v1->win[1] - v0->win[1];
60   GLfloat fx = v2->win[0] - v0->win[0];
61   GLfloat fy = v2->win[1] - v0->win[1];
62   GLfloat c = ex*fy-ey*fx;
63
64   if (c * SWRAST_CONTEXT(ctx)->_BackfaceSign > 0)
65      return 0;
66
67   return 1;
68}
69
70
71
72/*
73 * Render a flat-shaded color index triangle.
74 */
75#define NAME flat_ci_triangle
76#define INTERP_Z 1
77#define INTERP_FOG 1
78#define SETUP_CODE			\
79   span.interpMask |= SPAN_INDEX;	\
80   span.index = FloatToFixed(v2->index);\
81   span.indexStep = 0;
82#define RENDER_SPAN( span )  _swrast_write_index_span(ctx, &span);
83#include "s_tritemp.h"
84
85
86
87/*
88 * Render a smooth-shaded color index triangle.
89 */
90#define NAME smooth_ci_triangle
91#define INTERP_Z 1
92#define INTERP_FOG 1
93#define INTERP_INDEX 1
94#define RENDER_SPAN( span )  _swrast_write_index_span(ctx, &span);
95#include "s_tritemp.h"
96
97
98
99/*
100 * Render a flat-shaded RGBA triangle.
101 */
102#define NAME flat_rgba_triangle
103#define INTERP_Z 1
104#define INTERP_FOG 1
105#define SETUP_CODE				\
106   ASSERT(ctx->Texture._EnabledCoordUnits == 0);\
107   ASSERT(ctx->Light.ShadeModel==GL_FLAT);	\
108   span.interpMask |= SPAN_RGBA;		\
109   span.red = ChanToFixed(v2->color[0]);	\
110   span.green = ChanToFixed(v2->color[1]);	\
111   span.blue = ChanToFixed(v2->color[2]);	\
112   span.alpha = ChanToFixed(v2->color[3]);	\
113   span.redStep = 0;				\
114   span.greenStep = 0;				\
115   span.blueStep = 0;				\
116   span.alphaStep = 0;
117#define RENDER_SPAN( span )  _swrast_write_rgba_span(ctx, &span);
118#include "s_tritemp.h"
119
120
121
122/*
123 * Render a smooth-shaded RGBA triangle.
124 */
125#define NAME smooth_rgba_triangle
126#define INTERP_Z 1
127#define INTERP_FOG 1
128#define INTERP_RGB 1
129#define INTERP_ALPHA 1
130#define SETUP_CODE				\
131   {						\
132      /* texturing must be off */		\
133      ASSERT(ctx->Texture._EnabledCoordUnits == 0);	\
134      ASSERT(ctx->Light.ShadeModel==GL_SMOOTH);	\
135   }
136#define RENDER_SPAN( span )  _swrast_write_rgba_span(ctx, &span);
137#include "s_tritemp.h"
138
139
140
141/*
142 * Render an RGB, GL_DECAL, textured triangle.
143 * Interpolate S,T only w/out mipmapping or perspective correction.
144 *
145 * No fog.
146 */
147#define NAME simple_textured_triangle
148#define INTERP_INT_TEX 1
149#define S_SCALE twidth
150#define T_SCALE theight
151
152#define SETUP_CODE							\
153   SWcontext *swrast = SWRAST_CONTEXT(ctx);                             \
154   struct gl_texture_object *obj = ctx->Texture.Unit[0].Current2D;	\
155   const GLint b = obj->BaseLevel;					\
156   const GLfloat twidth = (GLfloat) obj->Image[0][b]->Width;		\
157   const GLfloat theight = (GLfloat) obj->Image[0][b]->Height;		\
158   const GLint twidth_log2 = obj->Image[0][b]->WidthLog2;		\
159   const GLchan *texture = (const GLchan *) obj->Image[0][b]->Data;	\
160   const GLint smask = obj->Image[0][b]->Width - 1;			\
161   const GLint tmask = obj->Image[0][b]->Height - 1;			\
162   if (!texture) {							\
163      /* this shouldn't happen */					\
164      return;								\
165   }
166
167#define RENDER_SPAN( span  )						\
168   GLuint i;								\
169   span.intTex[0] -= FIXED_HALF; /* off-by-one error? */		\
170   span.intTex[1] -= FIXED_HALF;					\
171   for (i = 0; i < span.end; i++) {					\
172      GLint s = FixedToInt(span.intTex[0]) & smask;			\
173      GLint t = FixedToInt(span.intTex[1]) & tmask;			\
174      GLint pos = (t << twidth_log2) + s;				\
175      pos = pos + pos + pos;  /* multiply by 3 */			\
176      span.array->rgb[i][RCOMP] = texture[pos];				\
177      span.array->rgb[i][GCOMP] = texture[pos+1];			\
178      span.array->rgb[i][BCOMP] = texture[pos+2];			\
179      span.intTex[0] += span.intTexStep[0];				\
180      span.intTex[1] += span.intTexStep[1];				\
181   }									\
182   (*swrast->Driver.WriteRGBSpan)(ctx, span.end, span.x, span.y,	\
183                                  (CONST GLchan (*)[3]) span.array->rgb,\
184                                  NULL );
185#include "s_tritemp.h"
186
187
188
189/*
190 * Render an RGB, GL_DECAL, textured triangle.
191 * Interpolate S,T, GL_LESS depth test, w/out mipmapping or
192 * perspective correction.
193 * Depth buffer bits must be <= sizeof(DEFAULT_SOFTWARE_DEPTH_TYPE)
194 *
195 * No fog.
196 */
197#define NAME simple_z_textured_triangle
198#define INTERP_Z 1
199#define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
200#define INTERP_INT_TEX 1
201#define S_SCALE twidth
202#define T_SCALE theight
203
204#define SETUP_CODE							\
205   SWcontext *swrast = SWRAST_CONTEXT(ctx);                             \
206   struct gl_texture_object *obj = ctx->Texture.Unit[0].Current2D;	\
207   const GLint b = obj->BaseLevel;					\
208   const GLfloat twidth = (GLfloat) obj->Image[0][b]->Width;		\
209   const GLfloat theight = (GLfloat) obj->Image[0][b]->Height;		\
210   const GLint twidth_log2 = obj->Image[0][b]->WidthLog2;		\
211   const GLchan *texture = (const GLchan *) obj->Image[0][b]->Data;	\
212   const GLint smask = obj->Image[0][b]->Width - 1;			\
213   const GLint tmask = obj->Image[0][b]->Height - 1;			\
214   if (!texture) {							\
215      /* this shouldn't happen */					\
216      return;								\
217   }
218
219#define RENDER_SPAN( span )						\
220   GLuint i;				    				\
221   span.intTex[0] -= FIXED_HALF; /* off-by-one error? */		\
222   span.intTex[1] -= FIXED_HALF;					\
223   for (i = 0; i < span.end; i++) {					\
224      const GLdepth z = FixedToDepth(span.z);				\
225      if (z < zRow[i]) {						\
226         GLint s = FixedToInt(span.intTex[0]) & smask;			\
227         GLint t = FixedToInt(span.intTex[1]) & tmask;			\
228         GLint pos = (t << twidth_log2) + s;				\
229         pos = pos + pos + pos;  /* multiply by 3 */			\
230         span.array->rgb[i][RCOMP] = texture[pos];			\
231         span.array->rgb[i][GCOMP] = texture[pos+1];			\
232         span.array->rgb[i][BCOMP] = texture[pos+2];			\
233         zRow[i] = z;							\
234         span.array->mask[i] = 1;					\
235      }									\
236      else {								\
237         span.array->mask[i] = 0;					\
238      }									\
239      span.intTex[0] += span.intTexStep[0];				\
240      span.intTex[1] += span.intTexStep[1];				\
241      span.z += span.zStep;						\
242   }									\
243   (*swrast->Driver.WriteRGBSpan)(ctx, span.end, span.x, span.y,	\
244                                  (CONST GLchan (*)[3]) span.array->rgb,\
245                                  span.array->mask );
246#include "s_tritemp.h"
247
248
249
250#if CHAN_TYPE != GL_FLOAT
251
252struct affine_info
253{
254   GLenum filter;
255   GLenum format;
256   GLenum envmode;
257   GLint smask, tmask;
258   GLint twidth_log2;
259   const GLchan *texture;
260   GLfixed er, eg, eb, ea;
261   GLint tbytesline, tsize;
262};
263
264
265/* This function can handle GL_NEAREST or GL_LINEAR sampling of 2D RGB or RGBA
266 * textures with GL_REPLACE, GL_MODULATE, GL_BLEND, GL_DECAL or GL_ADD
267 * texture env modes.
268 */
269static INLINE void
270affine_span(GLcontext *ctx, struct sw_span *span,
271            struct affine_info *info)
272{
273   GLchan sample[4];  /* the filtered texture sample */
274
275   /* Instead of defining a function for each mode, a test is done
276    * between the outer and inner loops. This is to reduce code size
277    * and complexity. Observe that an optimizing compiler kills
278    * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
279    */
280
281#define NEAREST_RGB			\
282   sample[RCOMP] = tex00[RCOMP];	\
283   sample[GCOMP] = tex00[GCOMP];	\
284   sample[BCOMP] = tex00[BCOMP];	\
285   sample[ACOMP] = CHAN_MAX
286
287#define LINEAR_RGB							\
288   sample[RCOMP] = (ti * (si * tex00[0] + sf * tex01[0]) +		\
289             tf * (si * tex10[0] + sf * tex11[0])) >> 2 * FIXED_SHIFT;	\
290   sample[GCOMP] = (ti * (si * tex00[1] + sf * tex01[1]) +		\
291             tf * (si * tex10[1] + sf * tex11[1])) >> 2 * FIXED_SHIFT;	\
292   sample[BCOMP] = (ti * (si * tex00[2] + sf * tex01[2]) +		\
293             tf * (si * tex10[2] + sf * tex11[2])) >> 2 * FIXED_SHIFT;	\
294   sample[ACOMP] = CHAN_MAX
295
296#define NEAREST_RGBA  COPY_CHAN4(sample, tex00)
297
298#define LINEAR_RGBA							\
299   sample[RCOMP] = (ti * (si * tex00[0] + sf * tex01[0]) +		\
300               tf * (si * tex10[0] + sf * tex11[0])) >> 2 * FIXED_SHIFT;\
301   sample[GCOMP] = (ti * (si * tex00[1] + sf * tex01[1]) +		\
302               tf * (si * tex10[1] + sf * tex11[1])) >> 2 * FIXED_SHIFT;\
303   sample[BCOMP] = (ti * (si * tex00[2] + sf * tex01[2]) +		\
304               tf * (si * tex10[2] + sf * tex11[2])) >> 2 * FIXED_SHIFT;\
305   sample[ACOMP] = (ti * (si * tex00[3] + sf * tex01[3]) +		\
306               tf * (si * tex10[3] + sf * tex11[3])) >> 2 * FIXED_SHIFT
307
308#define MODULATE							  \
309   dest[RCOMP] = span->red   * (sample[RCOMP] + 1u) >> (FIXED_SHIFT + 8); \
310   dest[GCOMP] = span->green * (sample[GCOMP] + 1u) >> (FIXED_SHIFT + 8); \
311   dest[BCOMP] = span->blue  * (sample[BCOMP] + 1u) >> (FIXED_SHIFT + 8); \
312   dest[ACOMP] = span->alpha * (sample[ACOMP] + 1u) >> (FIXED_SHIFT + 8)
313
314#define DECAL								\
315   dest[RCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->red +		\
316               ((sample[ACOMP] + 1) * sample[RCOMP] << FIXED_SHIFT))	\
317               >> (FIXED_SHIFT + 8);					\
318   dest[GCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->green +		\
319               ((sample[ACOMP] + 1) * sample[GCOMP] << FIXED_SHIFT))	\
320               >> (FIXED_SHIFT + 8);					\
321   dest[BCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->blue +		\
322               ((sample[ACOMP] + 1) * sample[BCOMP] << FIXED_SHIFT))	\
323               >> (FIXED_SHIFT + 8);					\
324   dest[ACOMP] = FixedToInt(span->alpha)
325
326#define BLEND								\
327   dest[RCOMP] = ((CHAN_MAX - sample[RCOMP]) * span->red		\
328               + (sample[RCOMP] + 1) * info->er) >> (FIXED_SHIFT + 8);	\
329   dest[GCOMP] = ((CHAN_MAX - sample[GCOMP]) * span->green		\
330               + (sample[GCOMP] + 1) * info->eg) >> (FIXED_SHIFT + 8);	\
331   dest[BCOMP] = ((CHAN_MAX - sample[BCOMP]) * span->blue		\
332               + (sample[BCOMP] + 1) * info->eb) >> (FIXED_SHIFT + 8);	\
333   dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8)
334
335#define REPLACE  COPY_CHAN4(dest, sample)
336
337#define ADD								\
338   {									\
339      GLint rSum = FixedToInt(span->red)   + (GLint) sample[RCOMP];	\
340      GLint gSum = FixedToInt(span->green) + (GLint) sample[GCOMP];	\
341      GLint bSum = FixedToInt(span->blue)  + (GLint) sample[BCOMP];	\
342      dest[RCOMP] = MIN2(rSum, CHAN_MAX);				\
343      dest[GCOMP] = MIN2(gSum, CHAN_MAX);				\
344      dest[BCOMP] = MIN2(bSum, CHAN_MAX);				\
345      dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8); \
346  }
347
348/* shortcuts */
349
350#define NEAREST_RGB_REPLACE		\
351   NEAREST_RGB;				\
352   dest[0] = sample[0];			\
353   dest[1] = sample[1];			\
354   dest[2] = sample[2];			\
355   dest[3] = FixedToInt(span->alpha);
356
357#define NEAREST_RGBA_REPLACE  COPY_CHAN4(dest, tex00)
358
359#define SPAN_NEAREST(DO_TEX,COMP)					\
360	for (i = 0; i < span->end; i++) {				\
361           /* Isn't it necessary to use FixedFloor below?? */		\
362           GLint s = FixedToInt(span->intTex[0]) & info->smask;		\
363           GLint t = FixedToInt(span->intTex[1]) & info->tmask;		\
364           GLint pos = (t << info->twidth_log2) + s;			\
365           const GLchan *tex00 = info->texture + COMP * pos;		\
366           DO_TEX;							\
367           span->red += span->redStep;					\
368	   span->green += span->greenStep;				\
369           span->blue += span->blueStep;				\
370	   span->alpha += span->alphaStep;				\
371	   span->intTex[0] += span->intTexStep[0];			\
372	   span->intTex[1] += span->intTexStep[1];			\
373           dest += 4;							\
374	}
375
376#define SPAN_LINEAR(DO_TEX,COMP)					\
377	for (i = 0; i < span->end; i++) {				\
378           /* Isn't it necessary to use FixedFloor below?? */		\
379           GLint s = FixedToInt(span->intTex[0]) & info->smask;		\
380           GLint t = FixedToInt(span->intTex[1]) & info->tmask;		\
381           GLfixed sf = span->intTex[0] & FIXED_FRAC_MASK;		\
382           GLfixed tf = span->intTex[1] & FIXED_FRAC_MASK;		\
383           GLfixed si = FIXED_FRAC_MASK - sf;				\
384           GLfixed ti = FIXED_FRAC_MASK - tf;				\
385           GLint pos = (t << info->twidth_log2) + s;			\
386           const GLchan *tex00 = info->texture + COMP * pos;		\
387           const GLchan *tex10 = tex00 + info->tbytesline;		\
388           const GLchan *tex01 = tex00 + COMP;				\
389           const GLchan *tex11 = tex10 + COMP;				\
390           (void) ti;							\
391           (void) si;							\
392           if (t == info->tmask) {					\
393              tex10 -= info->tsize;					\
394              tex11 -= info->tsize;					\
395           }								\
396           if (s == info->smask) {					\
397              tex01 -= info->tbytesline;				\
398              tex11 -= info->tbytesline;				\
399           }								\
400           DO_TEX;							\
401           span->red += span->redStep;					\
402	   span->green += span->greenStep;				\
403           span->blue += span->blueStep;				\
404	   span->alpha += span->alphaStep;				\
405	   span->intTex[0] += span->intTexStep[0];			\
406	   span->intTex[1] += span->intTexStep[1];			\
407           dest += 4;							\
408	}
409
410
411   GLuint i;
412   GLchan *dest = span->array->rgba[0];
413
414   span->intTex[0] -= FIXED_HALF;
415   span->intTex[1] -= FIXED_HALF;
416   switch (info->filter) {
417   case GL_NEAREST:
418      switch (info->format) {
419      case GL_RGB:
420         switch (info->envmode) {
421         case GL_MODULATE:
422            SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
423            break;
424         case GL_DECAL:
425         case GL_REPLACE:
426            SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
427            break;
428         case GL_BLEND:
429            SPAN_NEAREST(NEAREST_RGB;BLEND,3);
430            break;
431         case GL_ADD:
432            SPAN_NEAREST(NEAREST_RGB;ADD,3);
433            break;
434         default:
435            _mesa_problem(ctx, "bad tex env mode in SPAN_LINEAR");
436            return;
437         }
438         break;
439      case GL_RGBA:
440         switch(info->envmode) {
441         case GL_MODULATE:
442            SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
443            break;
444         case GL_DECAL:
445            SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
446            break;
447         case GL_BLEND:
448            SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
449            break;
450         case GL_ADD:
451            SPAN_NEAREST(NEAREST_RGBA;ADD,4);
452            break;
453         case GL_REPLACE:
454            SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
455            break;
456         default:
457            _mesa_problem(ctx, "bad tex env mode (2) in SPAN_LINEAR");
458            return;
459         }
460         break;
461      }
462      break;
463
464   case GL_LINEAR:
465      span->intTex[0] -= FIXED_HALF;
466      span->intTex[1] -= FIXED_HALF;
467      switch (info->format) {
468      case GL_RGB:
469         switch (info->envmode) {
470         case GL_MODULATE:
471            SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
472            break;
473         case GL_DECAL:
474         case GL_REPLACE:
475            SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
476            break;
477         case GL_BLEND:
478            SPAN_LINEAR(LINEAR_RGB;BLEND,3);
479            break;
480         case GL_ADD:
481            SPAN_LINEAR(LINEAR_RGB;ADD,3);
482            break;
483         default:
484            _mesa_problem(ctx, "bad tex env mode (3) in SPAN_LINEAR");
485            return;
486         }
487         break;
488      case GL_RGBA:
489         switch (info->envmode) {
490         case GL_MODULATE:
491            SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
492            break;
493         case GL_DECAL:
494            SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
495            break;
496         case GL_BLEND:
497            SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
498            break;
499         case GL_ADD:
500            SPAN_LINEAR(LINEAR_RGBA;ADD,4);
501            break;
502         case GL_REPLACE:
503            SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
504            break;
505         default:
506            _mesa_problem(ctx, "bad tex env mode (4) in SPAN_LINEAR");
507            return;
508         }
509         break;
510      }
511      break;
512   }
513   span->interpMask &= ~SPAN_RGBA;
514   ASSERT(span->arrayMask & SPAN_RGBA);
515   _swrast_write_rgba_span(ctx, span);
516
517#undef SPAN_NEAREST
518#undef SPAN_LINEAR
519}
520
521
522
523/*
524 * Render an RGB/RGBA textured triangle without perspective correction.
525 */
526#define NAME affine_textured_triangle
527#define INTERP_Z 1
528#define INTERP_FOG 1
529#define INTERP_RGB 1
530#define INTERP_ALPHA 1
531#define INTERP_INT_TEX 1
532#define S_SCALE twidth
533#define T_SCALE theight
534
535#define SETUP_CODE							\
536   struct affine_info info;						\
537   struct gl_texture_unit *unit = ctx->Texture.Unit+0;			\
538   struct gl_texture_object *obj = unit->Current2D;			\
539   const GLint b = obj->BaseLevel;					\
540   const GLfloat twidth = (GLfloat) obj->Image[0][b]->Width;		\
541   const GLfloat theight = (GLfloat) obj->Image[0][b]->Height;		\
542   info.texture = (const GLchan *) obj->Image[0][b]->Data;		\
543   info.twidth_log2 = obj->Image[0][b]->WidthLog2;			\
544   info.smask = obj->Image[0][b]->Width - 1;				\
545   info.tmask = obj->Image[0][b]->Height - 1;				\
546   info.format = obj->Image[0][b]->Format;				\
547   info.filter = obj->MinFilter;					\
548   info.envmode = unit->EnvMode;					\
549   span.arrayMask |= SPAN_RGBA;						\
550									\
551   if (info.envmode == GL_BLEND) {					\
552      /* potential off-by-one error here? (1.0f -> 2048 -> 0) */	\
553      info.er = FloatToFixed(unit->EnvColor[RCOMP] * CHAN_MAXF);	\
554      info.eg = FloatToFixed(unit->EnvColor[GCOMP] * CHAN_MAXF);	\
555      info.eb = FloatToFixed(unit->EnvColor[BCOMP] * CHAN_MAXF);	\
556      info.ea = FloatToFixed(unit->EnvColor[ACOMP] * CHAN_MAXF);	\
557   }									\
558   if (!info.texture) {							\
559      /* this shouldn't happen */					\
560      return;								\
561   }									\
562									\
563   switch (info.format) {						\
564   case GL_ALPHA:							\
565   case GL_LUMINANCE:							\
566   case GL_INTENSITY:							\
567      info.tbytesline = obj->Image[0][b]->Width;			\
568      break;								\
569   case GL_LUMINANCE_ALPHA:						\
570      info.tbytesline = obj->Image[0][b]->Width * 2;			\
571      break;								\
572   case GL_RGB:								\
573      info.tbytesline = obj->Image[0][b]->Width * 3;			\
574      break;								\
575   case GL_RGBA:							\
576      info.tbytesline = obj->Image[0][b]->Width * 4;			\
577      break;								\
578   default:								\
579      _mesa_problem(NULL, "Bad texture format in affine_texture_triangle");\
580      return;								\
581   }									\
582   info.tsize = obj->Image[0][b]->Height * info.tbytesline;
583
584#define RENDER_SPAN( span )   affine_span(ctx, &span, &info);
585
586#include "s_tritemp.h"
587
588
589
590struct persp_info
591{
592   GLenum filter;
593   GLenum format;
594   GLenum envmode;
595   GLint smask, tmask;
596   GLint twidth_log2;
597   const GLchan *texture;
598   GLfixed er, eg, eb, ea;   /* texture env color */
599   GLint tbytesline, tsize;
600};
601
602
603static INLINE void
604fast_persp_span(GLcontext *ctx, struct sw_span *span,
605		struct persp_info *info)
606{
607   GLchan sample[4];  /* the filtered texture sample */
608
609  /* Instead of defining a function for each mode, a test is done
610   * between the outer and inner loops. This is to reduce code size
611   * and complexity. Observe that an optimizing compiler kills
612   * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
613   */
614#define SPAN_NEAREST(DO_TEX,COMP)					\
615	for (i = 0; i < span->end; i++) {				\
616           GLdouble invQ = tex_coord[2] ?				\
617                                 (1.0 / tex_coord[2]) : 1.0;            \
618           GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);		\
619           GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);		\
620           GLint s = IFLOOR(s_tmp) & info->smask;	        	\
621           GLint t = IFLOOR(t_tmp) & info->tmask;	        	\
622           GLint pos = (t << info->twidth_log2) + s;			\
623           const GLchan *tex00 = info->texture + COMP * pos;		\
624           DO_TEX;							\
625           span->red += span->redStep;					\
626	   span->green += span->greenStep;				\
627           span->blue += span->blueStep;				\
628	   span->alpha += span->alphaStep;				\
629	   tex_coord[0] += tex_step[0];					\
630	   tex_coord[1] += tex_step[1];					\
631	   tex_coord[2] += tex_step[2];					\
632           dest += 4;							\
633	}
634
635#define SPAN_LINEAR(DO_TEX,COMP)					\
636	for (i = 0; i < span->end; i++) {				\
637           GLdouble invQ = tex_coord[2] ?				\
638                                 (1.0 / tex_coord[2]) : 1.0;            \
639           GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);		\
640           GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);		\
641           GLfixed s_fix = FloatToFixed(s_tmp) - FIXED_HALF;		\
642           GLfixed t_fix = FloatToFixed(t_tmp) - FIXED_HALF;        	\
643           GLint s = FixedToInt(FixedFloor(s_fix)) & info->smask;	\
644           GLint t = FixedToInt(FixedFloor(t_fix)) & info->tmask;	\
645           GLfixed sf = s_fix & FIXED_FRAC_MASK;			\
646           GLfixed tf = t_fix & FIXED_FRAC_MASK;			\
647           GLfixed si = FIXED_FRAC_MASK - sf;				\
648           GLfixed ti = FIXED_FRAC_MASK - tf;				\
649           GLint pos = (t << info->twidth_log2) + s;			\
650           const GLchan *tex00 = info->texture + COMP * pos;		\
651           const GLchan *tex10 = tex00 + info->tbytesline;		\
652           const GLchan *tex01 = tex00 + COMP;				\
653           const GLchan *tex11 = tex10 + COMP;				\
654           (void) ti;							\
655           (void) si;							\
656           if (t == info->tmask) {					\
657              tex10 -= info->tsize;					\
658              tex11 -= info->tsize;					\
659           }								\
660           if (s == info->smask) {					\
661              tex01 -= info->tbytesline;				\
662              tex11 -= info->tbytesline;				\
663           }								\
664           DO_TEX;							\
665           span->red   += span->redStep;				\
666	   span->green += span->greenStep;				\
667           span->blue  += span->blueStep;				\
668	   span->alpha += span->alphaStep;				\
669	   tex_coord[0] += tex_step[0];					\
670	   tex_coord[1] += tex_step[1];					\
671	   tex_coord[2] += tex_step[2];					\
672           dest += 4;							\
673	}
674
675   GLuint i;
676   GLfloat tex_coord[3], tex_step[3];
677   GLchan *dest = span->array->rgba[0];
678
679   const GLuint savedTexEnable = ctx->Texture._EnabledUnits;
680   ctx->Texture._EnabledUnits = 0;
681
682   tex_coord[0] = span->tex[0][0]  * (info->smask + 1);
683   tex_step[0] = span->texStepX[0][0] * (info->smask + 1);
684   tex_coord[1] = span->tex[0][1] * (info->tmask + 1);
685   tex_step[1] = span->texStepX[0][1] * (info->tmask + 1);
686   /* span->tex[0][2] only if 3D-texturing, here only 2D */
687   tex_coord[2] = span->tex[0][3];
688   tex_step[2] = span->texStepX[0][3];
689
690   switch (info->filter) {
691   case GL_NEAREST:
692      switch (info->format) {
693      case GL_RGB:
694         switch (info->envmode) {
695         case GL_MODULATE:
696            SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
697            break;
698         case GL_DECAL:
699         case GL_REPLACE:
700            SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
701            break;
702         case GL_BLEND:
703            SPAN_NEAREST(NEAREST_RGB;BLEND,3);
704            break;
705         case GL_ADD:
706            SPAN_NEAREST(NEAREST_RGB;ADD,3);
707            break;
708         default:
709            _mesa_problem(ctx, "bad tex env mode (5) in SPAN_LINEAR");
710            return;
711         }
712         break;
713      case GL_RGBA:
714         switch(info->envmode) {
715         case GL_MODULATE:
716            SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
717            break;
718         case GL_DECAL:
719            SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
720            break;
721         case GL_BLEND:
722            SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
723            break;
724         case GL_ADD:
725            SPAN_NEAREST(NEAREST_RGBA;ADD,4);
726            break;
727         case GL_REPLACE:
728            SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
729            break;
730         default:
731            _mesa_problem(ctx, "bad tex env mode (6) in SPAN_LINEAR");
732            return;
733         }
734         break;
735      }
736      break;
737
738   case GL_LINEAR:
739      switch (info->format) {
740      case GL_RGB:
741         switch (info->envmode) {
742         case GL_MODULATE:
743            SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
744            break;
745         case GL_DECAL:
746         case GL_REPLACE:
747            SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
748            break;
749         case GL_BLEND:
750            SPAN_LINEAR(LINEAR_RGB;BLEND,3);
751            break;
752         case GL_ADD:
753            SPAN_LINEAR(LINEAR_RGB;ADD,3);
754            break;
755         default:
756            _mesa_problem(ctx, "bad tex env mode (7) in SPAN_LINEAR");
757            return;
758         }
759         break;
760      case GL_RGBA:
761         switch (info->envmode) {
762         case GL_MODULATE:
763            SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
764            break;
765         case GL_DECAL:
766            SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
767            break;
768         case GL_BLEND:
769            SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
770            break;
771         case GL_ADD:
772            SPAN_LINEAR(LINEAR_RGBA;ADD,4);
773            break;
774         case GL_REPLACE:
775            SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
776            break;
777         default:
778            _mesa_problem(ctx, "bad tex env mode (8) in SPAN_LINEAR");
779            return;
780         }
781         break;
782      }
783      break;
784   }
785
786   ASSERT(span->arrayMask & SPAN_RGBA);
787   _swrast_write_rgba_span(ctx, span);
788
789#undef SPAN_NEAREST
790#undef SPAN_LINEAR
791
792   /* restore state */
793   ctx->Texture._EnabledUnits = savedTexEnable;
794}
795
796
797/*
798 * Render an perspective corrected RGB/RGBA textured triangle.
799 * The Q (aka V in Mesa) coordinate must be zero such that the divide
800 * by interpolated Q/W comes out right.
801 *
802 */
803#define NAME persp_textured_triangle
804#define INTERP_Z 1
805#define INTERP_W 1
806#define INTERP_FOG 1
807#define INTERP_RGB 1
808#define INTERP_ALPHA 1
809#define INTERP_TEX 1
810
811#define SETUP_CODE							\
812   struct persp_info info;						\
813   const struct gl_texture_unit *unit = ctx->Texture.Unit+0;		\
814   const struct gl_texture_object *obj = unit->Current2D;		\
815   const GLint b = obj->BaseLevel;					\
816   info.texture = (const GLchan *) obj->Image[0][b]->Data;		\
817   info.twidth_log2 = obj->Image[0][b]->WidthLog2;			\
818   info.smask = obj->Image[0][b]->Width - 1;				\
819   info.tmask = obj->Image[0][b]->Height - 1;				\
820   info.format = obj->Image[0][b]->Format;				\
821   info.filter = obj->MinFilter;					\
822   info.envmode = unit->EnvMode;					\
823									\
824   if (info.envmode == GL_BLEND) {					\
825      /* potential off-by-one error here? (1.0f -> 2048 -> 0) */	\
826      info.er = FloatToFixed(unit->EnvColor[RCOMP] * CHAN_MAXF);	\
827      info.eg = FloatToFixed(unit->EnvColor[GCOMP] * CHAN_MAXF);	\
828      info.eb = FloatToFixed(unit->EnvColor[BCOMP] * CHAN_MAXF);	\
829      info.ea = FloatToFixed(unit->EnvColor[ACOMP] * CHAN_MAXF);	\
830   }									\
831   if (!info.texture) {							\
832      /* this shouldn't happen */					\
833      return;								\
834   }									\
835									\
836   switch (info.format) {						\
837   case GL_ALPHA:							\
838   case GL_LUMINANCE:							\
839   case GL_INTENSITY:							\
840      info.tbytesline = obj->Image[0][b]->Width;			\
841      break;								\
842   case GL_LUMINANCE_ALPHA:						\
843      info.tbytesline = obj->Image[0][b]->Width * 2;			\
844      break;								\
845   case GL_RGB:								\
846      info.tbytesline = obj->Image[0][b]->Width * 3;			\
847      break;								\
848   case GL_RGBA:							\
849      info.tbytesline = obj->Image[0][b]->Width * 4;			\
850      break;								\
851   default:								\
852      _mesa_problem(NULL, "Bad texture format in persp_textured_triangle");\
853      return;								\
854   }									\
855   info.tsize = obj->Image[0][b]->Height * info.tbytesline;
856
857#define RENDER_SPAN( span )			\
858   span.interpMask &= ~SPAN_RGBA;		\
859   span.arrayMask |= SPAN_RGBA;			\
860   fast_persp_span(ctx, &span, &info);
861
862#include "s_tritemp.h"
863
864
865#endif /* CHAN_BITS != GL_FLOAT */
866
867
868
869
870/*
871 * Render a smooth-shaded, textured, RGBA triangle.
872 * Interpolate S,T,R with perspective correction, w/out mipmapping.
873 */
874#define NAME general_textured_triangle
875#define INTERP_Z 1
876#define INTERP_W 1
877#define INTERP_FOG 1
878#define INTERP_RGB 1
879#define INTERP_SPEC 1
880#define INTERP_ALPHA 1
881#define INTERP_TEX 1
882#define RENDER_SPAN( span )   _swrast_write_rgba_span(ctx, &span);
883#include "s_tritemp.h"
884
885
886
887/*
888 * This is the big one!
889 * Interpolate Z, RGB, Alpha, specular, fog, and N sets of texture coordinates.
890 * Yup, it's slow.
891 */
892#define NAME multitextured_triangle
893#define INTERP_Z 1
894#define INTERP_W 1
895#define INTERP_FOG 1
896#define INTERP_RGB 1
897#define INTERP_ALPHA 1
898#define INTERP_SPEC 1
899#define INTERP_MULTITEX 1
900#define RENDER_SPAN( span )   _swrast_write_rgba_span(ctx, &span);
901#include "s_tritemp.h"
902
903
904
905/*
906 * Special tri function for occlusion testing
907 */
908#define NAME occlusion_zless_triangle
909#define INTERP_Z 1
910#define SETUP_CODE						\
911   ASSERT(ctx->Depth.Test);					\
912   ASSERT(!ctx->Depth.Mask);					\
913   ASSERT(ctx->Depth.Func == GL_LESS);				\
914   if (ctx->OcclusionResult && !ctx->Occlusion.Active) {	\
915      return;							\
916   }
917#define RENDER_SPAN( span )						\
918   if (ctx->Visual.depthBits <= 16) {					\
919      GLuint i;								\
920      const GLushort *zRow = (const GLushort *)				\
921         _swrast_zbuffer_address(ctx, span.x, span.y);			\
922      for (i = 0; i < span.end; i++) {					\
923         GLdepth z = FixedToDepth(span.z);				\
924         if (z < zRow[i]) {						\
925            ctx->OcclusionResult = GL_TRUE;				\
926            ctx->Occlusion.PassedCounter++;				\
927         }								\
928         span.z += span.zStep;						\
929      }									\
930   }									\
931   else {								\
932      GLuint i;								\
933      const GLuint *zRow = (const GLuint *)				\
934         _swrast_zbuffer_address(ctx, span.x, span.y);			\
935      for (i = 0; i < span.end; i++) {					\
936         if ((GLuint)span.z < zRow[i]) {				\
937            ctx->OcclusionResult = GL_TRUE;				\
938            ctx->Occlusion.PassedCounter++;				\
939         }								\
940         span.z += span.zStep;						\
941      }									\
942   }
943#include "s_tritemp.h"
944
945
946
947static void
948nodraw_triangle( GLcontext *ctx,
949                 const SWvertex *v0,
950                 const SWvertex *v1,
951                 const SWvertex *v2 )
952{
953   (void) (ctx && v0 && v1 && v2);
954}
955
956
957/*
958 * This is used when separate specular color is enabled, but not
959 * texturing.  We add the specular color to the primary color,
960 * draw the triangle, then restore the original primary color.
961 * Inefficient, but seldom needed.
962 */
963void _swrast_add_spec_terms_triangle( GLcontext *ctx,
964				      const SWvertex *v0,
965				      const SWvertex *v1,
966				      const SWvertex *v2 )
967{
968   SWvertex *ncv0 = (SWvertex *)v0; /* drop const qualifier */
969   SWvertex *ncv1 = (SWvertex *)v1;
970   SWvertex *ncv2 = (SWvertex *)v2;
971#if CHAN_TYPE == GL_FLOAT
972   GLfloat rSum, gSum, bSum;
973#else
974   GLint rSum, gSum, bSum;
975#endif
976   GLchan c[3][4];
977   /* save original colors */
978   COPY_CHAN4( c[0], ncv0->color );
979   COPY_CHAN4( c[1], ncv1->color );
980   COPY_CHAN4( c[2], ncv2->color );
981   /* sum v0 */
982   rSum = ncv0->color[0] + ncv0->specular[0];
983   gSum = ncv0->color[1] + ncv0->specular[1];
984   bSum = ncv0->color[2] + ncv0->specular[2];
985   ncv0->color[0] = MIN2(rSum, CHAN_MAX);
986   ncv0->color[1] = MIN2(gSum, CHAN_MAX);
987   ncv0->color[2] = MIN2(bSum, CHAN_MAX);
988   /* sum v1 */
989   rSum = ncv1->color[0] + ncv1->specular[0];
990   gSum = ncv1->color[1] + ncv1->specular[1];
991   bSum = ncv1->color[2] + ncv1->specular[2];
992   ncv1->color[0] = MIN2(rSum, CHAN_MAX);
993   ncv1->color[1] = MIN2(gSum, CHAN_MAX);
994   ncv1->color[2] = MIN2(bSum, CHAN_MAX);
995   /* sum v2 */
996   rSum = ncv2->color[0] + ncv2->specular[0];
997   gSum = ncv2->color[1] + ncv2->specular[1];
998   bSum = ncv2->color[2] + ncv2->specular[2];
999   ncv2->color[0] = MIN2(rSum, CHAN_MAX);
1000   ncv2->color[1] = MIN2(gSum, CHAN_MAX);
1001   ncv2->color[2] = MIN2(bSum, CHAN_MAX);
1002   /* draw */
1003   SWRAST_CONTEXT(ctx)->SpecTriangle( ctx, ncv0, ncv1, ncv2 );
1004   /* restore original colors */
1005   COPY_CHAN4( ncv0->color, c[0] );
1006   COPY_CHAN4( ncv1->color, c[1] );
1007   COPY_CHAN4( ncv2->color, c[2] );
1008}
1009
1010
1011
1012#ifdef DEBUG
1013
1014/* record the current triangle function name */
1015const char *_mesa_triFuncName = NULL;
1016
1017#define USE(triFunc)				\
1018do {						\
1019    _mesa_triFuncName = #triFunc;		\
1020    /*printf("%s\n", _mesa_triFuncName);*/	\
1021    swrast->Triangle = triFunc;			\
1022} while (0)
1023
1024#else
1025
1026#define USE(triFunc)  swrast->Triangle = triFunc;
1027
1028#endif
1029
1030
1031
1032
1033/*
1034 * Determine which triangle rendering function to use given the current
1035 * rendering context.
1036 *
1037 * Please update the summary flag _SWRAST_NEW_TRIANGLE if you add or
1038 * remove tests to this code.
1039 */
1040void
1041_swrast_choose_triangle( GLcontext *ctx )
1042{
1043   SWcontext *swrast = SWRAST_CONTEXT(ctx);
1044   const GLboolean rgbmode = ctx->Visual.rgbMode;
1045
1046   if (ctx->Polygon.CullFlag &&
1047       ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK) {
1048      USE(nodraw_triangle);
1049      return;
1050   }
1051
1052   if (ctx->RenderMode==GL_RENDER) {
1053
1054      if (ctx->Polygon.SmoothFlag) {
1055         _swrast_set_aa_triangle_function(ctx);
1056         ASSERT(swrast->Triangle);
1057         return;
1058      }
1059
1060      /* special case for occlusion testing */
1061      if ((ctx->Depth.OcclusionTest || ctx->Occlusion.Active) &&
1062          ctx->Depth.Test &&
1063          ctx->Depth.Mask == GL_FALSE &&
1064          ctx->Depth.Func == GL_LESS &&
1065          !ctx->Stencil.Enabled) {
1066         if ((rgbmode &&
1067              ctx->Color.ColorMask[0] == 0 &&
1068              ctx->Color.ColorMask[1] == 0 &&
1069              ctx->Color.ColorMask[2] == 0 &&
1070              ctx->Color.ColorMask[3] == 0)
1071             ||
1072             (!rgbmode && ctx->Color.IndexMask == 0)) {
1073            USE(occlusion_zless_triangle);
1074            return;
1075         }
1076      }
1077
1078      if (ctx->Texture._EnabledCoordUnits || ctx->FragmentProgram._Active) {
1079         /* Ugh, we do a _lot_ of tests to pick the best textured tri func */
1080	 const struct gl_texture_object *texObj2D;
1081         const struct gl_texture_image *texImg;
1082         GLenum minFilter, magFilter, envMode;
1083         GLint format;
1084         texObj2D = ctx->Texture.Unit[0].Current2D;
1085         texImg = texObj2D ? texObj2D->Image[0][texObj2D->BaseLevel] : NULL;
1086         format = texImg ? texImg->TexFormat->MesaFormat : -1;
1087         minFilter = texObj2D ? texObj2D->MinFilter : (GLenum) 0;
1088         magFilter = texObj2D ? texObj2D->MagFilter : (GLenum) 0;
1089         envMode = ctx->Texture.Unit[0].EnvMode;
1090
1091         /* First see if we can use an optimized 2-D texture function */
1092         if (ctx->Texture._EnabledCoordUnits == 0x1
1093             && !ctx->FragmentProgram._Active
1094             && ctx->Texture.Unit[0]._ReallyEnabled == TEXTURE_2D_BIT
1095             && texObj2D->WrapS == GL_REPEAT
1096	     && texObj2D->WrapT == GL_REPEAT
1097             && texObj2D->_IsPowerOfTwo
1098             && texImg->Border == 0
1099             && texImg->Width == texImg->RowStride
1100             && (format == MESA_FORMAT_RGB || format == MESA_FORMAT_RGBA)
1101	     && minFilter == magFilter
1102	     && ctx->Light.Model.ColorControl == GL_SINGLE_COLOR
1103	     && ctx->Texture.Unit[0].EnvMode != GL_COMBINE_EXT) {
1104	    if (ctx->Hint.PerspectiveCorrection==GL_FASTEST) {
1105	       if (minFilter == GL_NEAREST
1106		   && format == MESA_FORMAT_RGB
1107		   && (envMode == GL_REPLACE || envMode == GL_DECAL)
1108		   && ((swrast->_RasterMask == (DEPTH_BIT | TEXTURE_BIT)
1109			&& ctx->Depth.Func == GL_LESS
1110			&& ctx->Depth.Mask == GL_TRUE)
1111		       || swrast->_RasterMask == TEXTURE_BIT)
1112		   && ctx->Polygon.StippleFlag == GL_FALSE
1113                   && ctx->Visual.depthBits <= 16) {
1114		  if (swrast->_RasterMask == (DEPTH_BIT | TEXTURE_BIT)) {
1115		     USE(simple_z_textured_triangle);
1116		  }
1117		  else {
1118		     USE(simple_textured_triangle);
1119		  }
1120	       }
1121	       else {
1122#if (CHAN_BITS == 16 || CHAN_BITS == 32)
1123                  USE(general_textured_triangle);
1124#else
1125                  USE(affine_textured_triangle);
1126#endif
1127	       }
1128	    }
1129	    else {
1130#if (CHAN_BITS == 16 || CHAN_BITS == 32)
1131               USE(general_textured_triangle);
1132#else
1133               USE(persp_textured_triangle);
1134#endif
1135	    }
1136	 }
1137         else {
1138            /* general case textured triangles */
1139            if (ctx->Texture._EnabledCoordUnits > 1) {
1140               USE(multitextured_triangle);
1141            }
1142            else {
1143               USE(general_textured_triangle);
1144            }
1145         }
1146      }
1147      else {
1148         ASSERT(!ctx->Texture._EnabledCoordUnits);
1149	 if (ctx->Light.ShadeModel==GL_SMOOTH) {
1150	    /* smooth shaded, no texturing, stippled or some raster ops */
1151            if (rgbmode) {
1152	       USE(smooth_rgba_triangle);
1153            }
1154            else {
1155               USE(smooth_ci_triangle);
1156            }
1157	 }
1158	 else {
1159	    /* flat shaded, no texturing, stippled or some raster ops */
1160            if (rgbmode) {
1161	       USE(flat_rgba_triangle);
1162            }
1163            else {
1164               USE(flat_ci_triangle);
1165            }
1166	 }
1167      }
1168   }
1169   else if (ctx->RenderMode==GL_FEEDBACK) {
1170      USE(_swrast_feedback_triangle);
1171   }
1172   else {
1173      /* GL_SELECT mode */
1174      USE(_swrast_select_triangle);
1175   }
1176}
1177