src/mesa/swrast/s_triangle.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.3
   4  *
   5  * Copyright (C) 1999-2005  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
  39 #include "s_aatriangle.h"
  40 #include "s_context.h"
  41 #include "s_depth.h"
  42 #include "s_feedback.h"
  43 #include "s_span.h"
  44 #include "s_triangle.h"
  45
  46
  47 /*
  48  * Just used for feedback mode.
  49  */
  50 GLboolean
  51 _swrast_culltriangle( GLcontext *ctx,
  52                       const SWvertex *v0,
  53                       const SWvertex *v1,
  54                       const SWvertex *v2 )
  55 {
  56    GLfloat ex = v1->win[0] - v0->win[0];
  57    GLfloat ey = v1->win[1] - v0->win[1];
  58    GLfloat fx = v2->win[0] - v0->win[0];
  59    GLfloat fy = v2->win[1] - v0->win[1];
  60    GLfloat c = ex*fy-ey*fx;
  61
  62    if (c * SWRAST_CONTEXT(ctx)->_BackfaceSign > 0)
  63       return 0;
  64
  65    return 1;
  66 }
  67
  68
  69
  70 /*
  71  * Render a flat-shaded color index triangle.
  72  */
  73 #define NAME flat_ci_triangle
  74 #define INTERP_Z 1
  75 #define INTERP_FOG 1
  76 #define SETUP_CODE                      \
  77    span.interpMask |= SPAN_INDEX;       \
  78    span.index = FloatToFixed(v2->index);\
  79    span.indexStep = 0;
  80 #define RENDER_SPAN( span )  _swrast_write_index_span(ctx, &span);
  81 #include "s_tritemp.h"
  82
  83
  84
  85 /*
  86  * Render a smooth-shaded color index triangle.
  87  */
  88 #define NAME smooth_ci_triangle
  89 #define INTERP_Z 1
  90 #define INTERP_FOG 1
  91 #define INTERP_INDEX 1
  92 #define RENDER_SPAN( span )  _swrast_write_index_span(ctx, &span);
  93 #include "s_tritemp.h"
  94
  95
  96
  97 /*
  98  * Render a flat-shaded RGBA triangle.
  99  */
 100 #define NAME flat_rgba_triangle
 101 #define INTERP_Z 1
 102 #define INTERP_FOG 1
 103 #define SETUP_CODE                              \
 104    ASSERT(ctx->Texture._EnabledCoordUnits == 0);\
 105    ASSERT(ctx->Light.ShadeModel==GL_FLAT);      \
 106    span.interpMask |= SPAN_RGBA;                \
 107    span.red = ChanToFixed(v2->color[0]);        \
 108    span.green = ChanToFixed(v2->color[1]);      \
 109    span.blue = ChanToFixed(v2->color[2]);       \
 110    span.alpha = ChanToFixed(v2->color[3]);      \
 111    span.redStep = 0;                            \
 112    span.greenStep = 0;                          \
 113    span.blueStep = 0;                           \
 114    span.alphaStep = 0;
 115 #define RENDER_SPAN( span )  _swrast_write_rgba_span(ctx, &span);
 116 #include "s_tritemp.h"
 117
 118
 119
 120 /*
 121  * Render a smooth-shaded RGBA triangle.
 122  */
 123 #define NAME smooth_rgba_triangle
 124 #define INTERP_Z 1
 125 #define INTERP_FOG 1
 126 #define INTERP_RGB 1
 127 #define INTERP_ALPHA 1
 128 #define SETUP_CODE                              \
 129    {                                            \
 130       /* texturing must be off */               \
 131       ASSERT(ctx->Texture._EnabledCoordUnits == 0);     \
 132       ASSERT(ctx->Light.ShadeModel==GL_SMOOTH); \
 133    }
 134 #define RENDER_SPAN( span )  _swrast_write_rgba_span(ctx, &span);
 135 #include "s_tritemp.h"
 136
 137
 138
 139 /*
 140  * Render an RGB, GL_DECAL, textured triangle.
 141  * Interpolate S,T only w/out mipmapping or perspective correction.
 142  *
 143  * No fog.
 144  */
 145 #define NAME simple_textured_triangle
 146 #define INTERP_INT_TEX 1
 147 #define S_SCALE twidth
 148 #define T_SCALE theight
 149
 150 #define SETUP_CODE                                                      \
 151    SWcontext *swrast = SWRAST_CONTEXT(ctx);                             \
 152    struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0][0];\
 153    struct gl_texture_object *obj = ctx->Texture.Unit[0].Current2D;      \
 154    const GLint b = obj->BaseLevel;                                      \
 155    const GLfloat twidth = (GLfloat) obj->Image[0][b]->Width;            \
 156    const GLfloat theight = (GLfloat) obj->Image[0][b]->Height;          \
 157    const GLint twidth_log2 = obj->Image[0][b]->WidthLog2;               \
 158    const GLchan *texture = (const GLchan *) obj->Image[0][b]->Data;     \
 159    const GLint smask = obj->Image[0][b]->Width - 1;                     \
 160    const GLint tmask = obj->Image[0][b]->Height - 1;                    \
 161    if (!texture) {                                                      \
 162       /* this shouldn't happen */                                       \
 163       return;                                                           \
 164    }
 165
 166 #define RENDER_SPAN( span  )                                            \
 167    GLuint i;                                                            \
 168    span.intTex[0] -= FIXED_HALF; /* off-by-one error? */                \
 169    span.intTex[1] -= FIXED_HALF;                                        \
 170    for (i = 0; i < span.end; i++) {                                     \
 171       GLint s = FixedToInt(span.intTex[0]) & smask;                     \
 172       GLint t = FixedToInt(span.intTex[1]) & tmask;                     \
 173       GLint pos = (t << twidth_log2) + s;                               \
 174       pos = pos + pos + pos;  /* multiply by 3 */                       \
 175       span.array->rgb[i][RCOMP] = texture[pos];                         \
 176       span.array->rgb[i][GCOMP] = texture[pos+1];                       \
 177       span.array->rgb[i][BCOMP] = texture[pos+2];                       \
 178       span.intTex[0] += span.intTexStep[0];                             \
 179       span.intTex[1] += span.intTexStep[1];                             \
 180    }                                                                    \
 181    if (swrast->Driver.WriteRGBSpan)                                     \
 182       swrast->Driver.WriteRGBSpan(ctx, rb, span.end, span.x, span.y,    \
 183                                   (CONST GLchan (*)[3]) span.array->rgb,\
 184                                   NULL );                               \
 185    else                                                                 \
 186       rb->PutRowRGB(ctx, rb, span.end, span.x, span.y, span.array->rgb, NULL);
 187
 188 #include "s_tritemp.h"
 189
 190
 191
 192 /*
 193  * Render an RGB, GL_DECAL, textured triangle.
 194  * Interpolate S,T, GL_LESS depth test, w/out mipmapping or
 195  * perspective correction.
 196  * Depth buffer bits must be <= sizeof(DEFAULT_SOFTWARE_DEPTH_TYPE)
 197  *
 198  * No fog.
 199  */
 200 #define NAME simple_z_textured_triangle
 201 #define INTERP_Z 1
 202 #define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 203 #define INTERP_INT_TEX 1
 204 #define S_SCALE twidth
 205 #define T_SCALE theight
 206
 207 #define SETUP_CODE                                                      \
 208    SWcontext *swrast = SWRAST_CONTEXT(ctx);                             \
 209    struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0][0];\
 210    struct gl_texture_object *obj = ctx->Texture.Unit[0].Current2D;      \
 211    const GLint b = obj->BaseLevel;                                      \
 212    const GLfloat twidth = (GLfloat) obj->Image[0][b]->Width;            \
 213    const GLfloat theight = (GLfloat) obj->Image[0][b]->Height;          \
 214    const GLint twidth_log2 = obj->Image[0][b]->WidthLog2;               \
 215    const GLchan *texture = (const GLchan *) obj->Image[0][b]->Data;     \
 216    const GLint smask = obj->Image[0][b]->Width - 1;                     \
 217    const GLint tmask = obj->Image[0][b]->Height - 1;                    \
 218    if (!texture) {                                                      \
 219       /* this shouldn't happen */                                       \
 220       return;                                                           \
 221    }
 222
 223 #define RENDER_SPAN( span )                                             \
 224    GLuint i;                                                            \
 225    span.intTex[0] -= FIXED_HALF; /* off-by-one error? */                \
 226    span.intTex[1] -= FIXED_HALF;                                        \
 227    for (i = 0; i < span.end; i++) {                                     \
 228       const GLdepth z = FixedToDepth(span.z);                           \
 229       if (z < zRow[i]) {                                                \
 230          GLint s = FixedToInt(span.intTex[0]) & smask;                  \
 231          GLint t = FixedToInt(span.intTex[1]) & tmask;                  \
 232          GLint pos = (t << twidth_log2) + s;                            \
 233          pos = pos + pos + pos;  /* multiply by 3 */                    \
 234          span.array->rgb[i][RCOMP] = texture[pos];                      \
 235          span.array->rgb[i][GCOMP] = texture[pos+1];                    \
 236          span.array->rgb[i][BCOMP] = texture[pos+2];                    \
 237          zRow[i] = z;                                                   \
 238          span.array->mask[i] = 1;                                       \
 239       }                                                                 \
 240       else {                                                            \
 241          span.array->mask[i] = 0;                                       \
 242       }                                                                 \
 243       span.intTex[0] += span.intTexStep[0];                             \
 244       span.intTex[1] += span.intTexStep[1];                             \
 245       span.z += span.zStep;                                             \
 246    }                                                                    \
 247    if (swrast->Driver.WriteRGBSpan)                                     \
 248       swrast->Driver.WriteRGBSpan(ctx, rb, span.end, span.x, span.y,    \
 249                                   (CONST GLchan (*)[3]) span.array->rgb,\
 250                                   span.array->mask );                   \
 251    else                                                                 \
 252       rb->PutRowRGB(ctx, rb, span.end, span.x, span.y, span.array->rgb, NULL);
 253
 254 #include "s_tritemp.h"
 255
 256
 257
 258 #if CHAN_TYPE != GL_FLOAT
 259
 260 struct affine_info
 261 {
 262    GLenum filter;
 263    GLenum format;
 264    GLenum envmode;
 265    GLint smask, tmask;
 266    GLint twidth_log2;
 267    const GLchan *texture;
 268    GLfixed er, eg, eb, ea;
 269    GLint tbytesline, tsize;
 270 };
 271
 272
 273 /* This function can handle GL_NEAREST or GL_LINEAR sampling of 2D RGB or RGBA
 274  * textures with GL_REPLACE, GL_MODULATE, GL_BLEND, GL_DECAL or GL_ADD
 275  * texture env modes.
 276  */
 277 static INLINE void
 278 affine_span(GLcontext *ctx, struct sw_span *span,
 279             struct affine_info *info)
 280 {
 281    GLchan sample[4];  /* the filtered texture sample */
 282
 283    /* Instead of defining a function for each mode, a test is done
 284     * between the outer and inner loops. This is to reduce code size
 285     * and complexity. Observe that an optimizing compiler kills
 286     * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
 287     */
 288
 289 #define NEAREST_RGB                     \
 290    sample[RCOMP] = tex00[RCOMP];        \
 291    sample[GCOMP] = tex00[GCOMP];        \
 292    sample[BCOMP] = tex00[BCOMP];        \
 293    sample[ACOMP] = CHAN_MAX
 294
 295 #define LINEAR_RGB                                                      \
 296    sample[RCOMP] = (ti * (si * tex00[0] + sf * tex01[0]) +              \
 297              tf * (si * tex10[0] + sf * tex11[0])) >> 2 * FIXED_SHIFT;  \
 298    sample[GCOMP] = (ti * (si * tex00[1] + sf * tex01[1]) +              \
 299              tf * (si * tex10[1] + sf * tex11[1])) >> 2 * FIXED_SHIFT;  \
 300    sample[BCOMP] = (ti * (si * tex00[2] + sf * tex01[2]) +              \
 301              tf * (si * tex10[2] + sf * tex11[2])) >> 2 * FIXED_SHIFT;  \
 302    sample[ACOMP] = CHAN_MAX
 303
 304 #define NEAREST_RGBA  COPY_CHAN4(sample, tex00)
 305
 306 #define LINEAR_RGBA                                                     \
 307    sample[RCOMP] = (ti * (si * tex00[0] + sf * tex01[0]) +              \
 308                tf * (si * tex10[0] + sf * tex11[0])) >> 2 * FIXED_SHIFT;\
 309    sample[GCOMP] = (ti * (si * tex00[1] + sf * tex01[1]) +              \
 310                tf * (si * tex10[1] + sf * tex11[1])) >> 2 * FIXED_SHIFT;\
 311    sample[BCOMP] = (ti * (si * tex00[2] + sf * tex01[2]) +              \
 312                tf * (si * tex10[2] + sf * tex11[2])) >> 2 * FIXED_SHIFT;\
 313    sample[ACOMP] = (ti * (si * tex00[3] + sf * tex01[3]) +              \
 314                tf * (si * tex10[3] + sf * tex11[3])) >> 2 * FIXED_SHIFT
 315
 316 #define MODULATE                                                          \
 317    dest[RCOMP] = span->red   * (sample[RCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 318    dest[GCOMP] = span->green * (sample[GCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 319    dest[BCOMP] = span->blue  * (sample[BCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 320    dest[ACOMP] = span->alpha * (sample[ACOMP] + 1u) >> (FIXED_SHIFT + 8)
 321
 322 #define DECAL                                                           \
 323    dest[RCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->red +              \
 324                ((sample[ACOMP] + 1) * sample[RCOMP] << FIXED_SHIFT))    \
 325                >> (FIXED_SHIFT + 8);                                    \
 326    dest[GCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->green +            \
 327                ((sample[ACOMP] + 1) * sample[GCOMP] << FIXED_SHIFT))    \
 328                >> (FIXED_SHIFT + 8);                                    \
 329    dest[BCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->blue +             \
 330                ((sample[ACOMP] + 1) * sample[BCOMP] << FIXED_SHIFT))    \
 331                >> (FIXED_SHIFT + 8);                                    \
 332    dest[ACOMP] = FixedToInt(span->alpha)
 333
 334 #define BLEND                                                           \
 335    dest[RCOMP] = ((CHAN_MAX - sample[RCOMP]) * span->red                \
 336                + (sample[RCOMP] + 1) * info->er) >> (FIXED_SHIFT + 8);  \
 337    dest[GCOMP] = ((CHAN_MAX - sample[GCOMP]) * span->green              \
 338                + (sample[GCOMP] + 1) * info->eg) >> (FIXED_SHIFT + 8);  \
 339    dest[BCOMP] = ((CHAN_MAX - sample[BCOMP]) * span->blue               \
 340                + (sample[BCOMP] + 1) * info->eb) >> (FIXED_SHIFT + 8);  \
 341    dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8)
 342
 343 #define REPLACE  COPY_CHAN4(dest, sample)
 344
 345 #define ADD                                                             \
 346    {                                                                    \
 347       GLint rSum = FixedToInt(span->red)   + (GLint) sample[RCOMP];     \
 348       GLint gSum = FixedToInt(span->green) + (GLint) sample[GCOMP];     \
 349       GLint bSum = FixedToInt(span->blue)  + (GLint) sample[BCOMP];     \
 350       dest[RCOMP] = MIN2(rSum, CHAN_MAX);                               \
 351       dest[GCOMP] = MIN2(gSum, CHAN_MAX);                               \
 352       dest[BCOMP] = MIN2(bSum, CHAN_MAX);                               \
 353       dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8); \
 354   }
 355
 356 /* shortcuts */
 357
 358 #define NEAREST_RGB_REPLACE             \
 359    NEAREST_RGB;                         \
 360    dest[0] = sample[0];                 \
 361    dest[1] = sample[1];                 \
 362    dest[2] = sample[2];                 \
 363    dest[3] = FixedToInt(span->alpha);
 364
 365 #define NEAREST_RGBA_REPLACE  COPY_CHAN4(dest, tex00)
 366
 367 #define SPAN_NEAREST(DO_TEX,COMP)                                       \
 368         for (i = 0; i < span->end; i++) {                               \
 369            /* Isn't it necessary to use FixedFloor below?? */           \
 370            GLint s = FixedToInt(span->intTex[0]) & info->smask;         \
 371            GLint t = FixedToInt(span->intTex[1]) & info->tmask;         \
 372            GLint pos = (t << info->twidth_log2) + s;                    \
 373            const GLchan *tex00 = info->texture + COMP * pos;            \
 374            DO_TEX;                                                      \
 375            span->red += span->redStep;                                  \
 376            span->green += span->greenStep;                              \
 377            span->blue += span->blueStep;                                \
 378            span->alpha += span->alphaStep;                              \
 379            span->intTex[0] += span->intTexStep[0];                      \
 380            span->intTex[1] += span->intTexStep[1];                      \
 381            dest += 4;                                                   \
 382         }
 383
 384 #define SPAN_LINEAR(DO_TEX,COMP)                                        \
 385         for (i = 0; i < span->end; i++) {                               \
 386            /* Isn't it necessary to use FixedFloor below?? */           \
 387            GLint s = FixedToInt(span->intTex[0]) & info->smask;         \
 388            GLint t = FixedToInt(span->intTex[1]) & info->tmask;         \
 389            GLfixed sf = span->intTex[0] & FIXED_FRAC_MASK;              \
 390            GLfixed tf = span->intTex[1] & FIXED_FRAC_MASK;              \
 391            GLfixed si = FIXED_FRAC_MASK - sf;                           \
 392            GLfixed ti = FIXED_FRAC_MASK - tf;                           \
 393            GLint pos = (t << info->twidth_log2) + s;                    \
 394            const GLchan *tex00 = info->texture + COMP * pos;            \
 395            const GLchan *tex10 = tex00 + info->tbytesline;              \
 396            const GLchan *tex01 = tex00 + COMP;                          \
 397            const GLchan *tex11 = tex10 + COMP;                          \
 398            (void) ti;                                                   \
 399            (void) si;                                                   \
 400            if (t == info->tmask) {                                      \
 401               tex10 -= info->tsize;                                     \
 402               tex11 -= info->tsize;                                     \
 403            }                                                            \
 404            if (s == info->smask) {                                      \
 405               tex01 -= info->tbytesline;                                \
 406               tex11 -= info->tbytesline;                                \
 407            }                                                            \
 408            DO_TEX;                                                      \
 409            span->red += span->redStep;                                  \
 410            span->green += span->greenStep;                              \
 411            span->blue += span->blueStep;                                \
 412            span->alpha += span->alphaStep;                              \
 413            span->intTex[0] += span->intTexStep[0];                      \
 414            span->intTex[1] += span->intTexStep[1];                      \
 415            dest += 4;                                                   \
 416         }
 417
 418
 419    GLuint i;
 420    GLchan *dest = span->array->rgba[0];
 421
 422    span->intTex[0] -= FIXED_HALF;
 423    span->intTex[1] -= FIXED_HALF;
 424    switch (info->filter) {
 425    case GL_NEAREST:
 426       switch (info->format) {
 427       case GL_RGB:
 428          switch (info->envmode) {
 429          case GL_MODULATE:
 430             SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
 431             break;
 432          case GL_DECAL:
 433          case GL_REPLACE:
 434             SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
 435             break;
 436          case GL_BLEND:
 437             SPAN_NEAREST(NEAREST_RGB;BLEND,3);
 438             break;
 439          case GL_ADD:
 440             SPAN_NEAREST(NEAREST_RGB;ADD,3);
 441             break;
 442          default:
 443             _mesa_problem(ctx, "bad tex env mode in SPAN_LINEAR");
 444             return;
 445          }
 446          break;
 447       case GL_RGBA:
 448          switch(info->envmode) {
 449          case GL_MODULATE:
 450             SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
 451             break;
 452          case GL_DECAL:
 453             SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
 454             break;
 455          case GL_BLEND:
 456             SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
 457             break;
 458          case GL_ADD:
 459             SPAN_NEAREST(NEAREST_RGBA;ADD,4);
 460             break;
 461          case GL_REPLACE:
 462             SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
 463             break;
 464          default:
 465             _mesa_problem(ctx, "bad tex env mode (2) in SPAN_LINEAR");
 466             return;
 467          }
 468          break;
 469       }
 470       break;
 471
 472    case GL_LINEAR:
 473       span->intTex[0] -= FIXED_HALF;
 474       span->intTex[1] -= FIXED_HALF;
 475       switch (info->format) {
 476       case GL_RGB:
 477          switch (info->envmode) {
 478          case GL_MODULATE:
 479             SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
 480             break;
 481          case GL_DECAL:
 482          case GL_REPLACE:
 483             SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
 484             break;
 485          case GL_BLEND:
 486             SPAN_LINEAR(LINEAR_RGB;BLEND,3);
 487             break;
 488          case GL_ADD:
 489             SPAN_LINEAR(LINEAR_RGB;ADD,3);
 490             break;
 491          default:
 492             _mesa_problem(ctx, "bad tex env mode (3) in SPAN_LINEAR");
 493             return;
 494          }
 495          break;
 496       case GL_RGBA:
 497          switch (info->envmode) {
 498          case GL_MODULATE:
 499             SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
 500             break;
 501          case GL_DECAL:
 502             SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
 503             break;
 504          case GL_BLEND:
 505             SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
 506             break;
 507          case GL_ADD:
 508             SPAN_LINEAR(LINEAR_RGBA;ADD,4);
 509             break;
 510          case GL_REPLACE:
 511             SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
 512             break;
 513          default:
 514             _mesa_problem(ctx, "bad tex env mode (4) in SPAN_LINEAR");
 515             return;
 516          }
 517          break;
 518       }
 519       break;
 520    }
 521    span->interpMask &= ~SPAN_RGBA;
 522    ASSERT(span->arrayMask & SPAN_RGBA);
 523    _swrast_write_rgba_span(ctx, span);
 524
 525 #undef SPAN_NEAREST
 526 #undef SPAN_LINEAR
 527 }
 528
 529
 530
 531 /*
 532  * Render an RGB/RGBA textured triangle without perspective correction.
 533  */
 534 #define NAME affine_textured_triangle
 535 #define INTERP_Z 1
 536 #define INTERP_FOG 1
 537 #define INTERP_RGB 1
 538 #define INTERP_ALPHA 1
 539 #define INTERP_INT_TEX 1
 540 #define S_SCALE twidth
 541 #define T_SCALE theight
 542
 543 #define SETUP_CODE                                                      \
 544    struct affine_info info;                                             \
 545    struct gl_texture_unit *unit = ctx->Texture.Unit+0;                  \
 546    struct gl_texture_object *obj = unit->Current2D;                     \
 547    const GLint b = obj->BaseLevel;                                      \
 548    const GLfloat twidth = (GLfloat) obj->Image[0][b]->Width;            \
 549    const GLfloat theight = (GLfloat) obj->Image[0][b]->Height;          \
 550    info.texture = (const GLchan *) obj->Image[0][b]->Data;              \
 551    info.twidth_log2 = obj->Image[0][b]->WidthLog2;                      \
 552    info.smask = obj->Image[0][b]->Width - 1;                            \
 553    info.tmask = obj->Image[0][b]->Height - 1;                           \
 554    info.format = obj->Image[0][b]->Format;                              \
 555    info.filter = obj->MinFilter;                                        \
 556    info.envmode = unit->EnvMode;                                        \
 557    span.arrayMask |= SPAN_RGBA;                                         \
 558                                                                         \
 559    if (info.envmode == GL_BLEND) {                                      \
 560       /* potential off-by-one error here? (1.0f -> 2048 -> 0) */        \
 561       info.er = FloatToFixed(unit->EnvColor[RCOMP] * CHAN_MAXF);        \
 562       info.eg = FloatToFixed(unit->EnvColor[GCOMP] * CHAN_MAXF);        \
 563       info.eb = FloatToFixed(unit->EnvColor[BCOMP] * CHAN_MAXF);        \
 564       info.ea = FloatToFixed(unit->EnvColor[ACOMP] * CHAN_MAXF);        \
 565    }                                                                    \
 566    if (!info.texture) {                                                 \
 567       /* this shouldn't happen */                                       \
 568       return;                                                           \
 569    }                                                                    \
 570                                                                         \
 571    switch (info.format) {                                               \
 572    case GL_ALPHA:                                                       \
 573    case GL_LUMINANCE:                                                   \
 574    case GL_INTENSITY:                                                   \
 575       info.tbytesline = obj->Image[0][b]->Width;                        \
 576       break;                                                            \
 577    case GL_LUMINANCE_ALPHA:                                             \
 578       info.tbytesline = obj->Image[0][b]->Width * 2;                    \
 579       break;                                                            \
 580    case GL_RGB:                                                         \
 581       info.tbytesline = obj->Image[0][b]->Width * 3;                    \
 582       break;                                                            \
 583    case GL_RGBA:                                                        \
 584       info.tbytesline = obj->Image[0][b]->Width * 4;                    \
 585       break;                                                            \
 586    default:                                                             \
 587       _mesa_problem(NULL, "Bad texture format in affine_texture_triangle");\
 588       return;                                                           \
 589    }                                                                    \
 590    info.tsize = obj->Image[0][b]->Height * info.tbytesline;
 591
 592 #define RENDER_SPAN( span )   affine_span(ctx, &span, &info);
 593
 594 #include "s_tritemp.h"
 595
 596
 597
 598 struct persp_info
 599 {
 600    GLenum filter;
 601    GLenum format;
 602    GLenum envmode;
 603    GLint smask, tmask;
 604    GLint twidth_log2;
 605    const GLchan *texture;
 606    GLfixed er, eg, eb, ea;   /* texture env color */
 607    GLint tbytesline, tsize;
 608 };
 609
 610
 611 static INLINE void
 612 fast_persp_span(GLcontext *ctx, struct sw_span *span,
 613                 struct persp_info *info)
 614 {
 615    GLchan sample[4];  /* the filtered texture sample */
 616
 617   /* Instead of defining a function for each mode, a test is done
 618    * between the outer and inner loops. This is to reduce code size
 619    * and complexity. Observe that an optimizing compiler kills
 620    * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
 621    */
 622 #define SPAN_NEAREST(DO_TEX,COMP)                                       \
 623         for (i = 0; i < span->end; i++) {                               \
 624            GLdouble invQ = tex_coord[2] ?                               \
 625                                  (1.0 / tex_coord[2]) : 1.0;            \
 626            GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);             \
 627            GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);             \
 628            GLint s = IFLOOR(s_tmp) & info->smask;                       \
 629            GLint t = IFLOOR(t_tmp) & info->tmask;                       \
 630            GLint pos = (t << info->twidth_log2) + s;                    \
 631            const GLchan *tex00 = info->texture + COMP * pos;            \
 632            DO_TEX;                                                      \
 633            span->red += span->redStep;                                  \
 634            span->green += span->greenStep;                              \
 635            span->blue += span->blueStep;                                \
 636            span->alpha += span->alphaStep;                              \
 637            tex_coord[0] += tex_step[0];                                 \
 638            tex_coord[1] += tex_step[1];                                 \
 639            tex_coord[2] += tex_step[2];                                 \
 640            dest += 4;                                                   \
 641         }
 642
 643 #define SPAN_LINEAR(DO_TEX,COMP)                                        \
 644         for (i = 0; i < span->end; i++) {                               \
 645            GLdouble invQ = tex_coord[2] ?                               \
 646                                  (1.0 / tex_coord[2]) : 1.0;            \
 647            GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);             \
 648            GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);             \
 649            GLfixed s_fix = FloatToFixed(s_tmp) - FIXED_HALF;            \
 650            GLfixed t_fix = FloatToFixed(t_tmp) - FIXED_HALF;            \
 651            GLint s = FixedToInt(FixedFloor(s_fix)) & info->smask;       \
 652            GLint t = FixedToInt(FixedFloor(t_fix)) & info->tmask;       \
 653            GLfixed sf = s_fix & FIXED_FRAC_MASK;                        \
 654            GLfixed tf = t_fix & FIXED_FRAC_MASK;                        \
 655            GLfixed si = FIXED_FRAC_MASK - sf;                           \
 656            GLfixed ti = FIXED_FRAC_MASK - tf;                           \
 657            GLint pos = (t << info->twidth_log2) + s;                    \
 658            const GLchan *tex00 = info->texture + COMP * pos;            \
 659            const GLchan *tex10 = tex00 + info->tbytesline;              \
 660            const GLchan *tex01 = tex00 + COMP;                          \
 661            const GLchan *tex11 = tex10 + COMP;                          \
 662            (void) ti;                                                   \
 663            (void) si;                                                   \
 664            if (t == info->tmask) {                                      \
 665               tex10 -= info->tsize;                                     \
 666               tex11 -= info->tsize;                                     \
 667            }                                                            \
 668            if (s == info->smask) {                                      \
 669               tex01 -= info->tbytesline;                                \
 670               tex11 -= info->tbytesline;                                \
 671            }                                                            \
 672            DO_TEX;                                                      \
 673            span->red   += span->redStep;                                \
 674            span->green += span->greenStep;                              \
 675            span->blue  += span->blueStep;                               \
 676            span->alpha += span->alphaStep;                              \
 677            tex_coord[0] += tex_step[0];                                 \
 678            tex_coord[1] += tex_step[1];                                 \
 679            tex_coord[2] += tex_step[2];                                 \
 680            dest += 4;                                                   \
 681         }
 682
 683    GLuint i;
 684    GLfloat tex_coord[3], tex_step[3];
 685    GLchan *dest = span->array->rgba[0];
 686
 687    const GLuint savedTexEnable = ctx->Texture._EnabledUnits;
 688    ctx->Texture._EnabledUnits = 0;
 689
 690    tex_coord[0] = span->tex[0][0]  * (info->smask + 1);
 691    tex_step[0] = span->texStepX[0][0] * (info->smask + 1);
 692    tex_coord[1] = span->tex[0][1] * (info->tmask + 1);
 693    tex_step[1] = span->texStepX[0][1] * (info->tmask + 1);
 694    /* span->tex[0][2] only if 3D-texturing, here only 2D */
 695    tex_coord[2] = span->tex[0][3];
 696    tex_step[2] = span->texStepX[0][3];
 697
 698    switch (info->filter) {
 699    case GL_NEAREST:
 700       switch (info->format) {
 701       case GL_RGB:
 702          switch (info->envmode) {
 703          case GL_MODULATE:
 704             SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
 705             break;
 706          case GL_DECAL:
 707          case GL_REPLACE:
 708             SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
 709             break;
 710          case GL_BLEND:
 711             SPAN_NEAREST(NEAREST_RGB;BLEND,3);
 712             break;
 713          case GL_ADD:
 714             SPAN_NEAREST(NEAREST_RGB;ADD,3);
 715             break;
 716          default:
 717             _mesa_problem(ctx, "bad tex env mode (5) in SPAN_LINEAR");
 718             return;
 719          }
 720          break;
 721       case GL_RGBA:
 722          switch(info->envmode) {
 723          case GL_MODULATE:
 724             SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
 725             break;
 726          case GL_DECAL:
 727             SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
 728             break;
 729          case GL_BLEND:
 730             SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
 731             break;
 732          case GL_ADD:
 733             SPAN_NEAREST(NEAREST_RGBA;ADD,4);
 734             break;
 735          case GL_REPLACE:
 736             SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
 737             break;
 738          default:
 739             _mesa_problem(ctx, "bad tex env mode (6) in SPAN_LINEAR");
 740             return;
 741          }
 742          break;
 743       }
 744       break;
 745
 746    case GL_LINEAR:
 747       switch (info->format) {
 748       case GL_RGB:
 749          switch (info->envmode) {
 750          case GL_MODULATE:
 751             SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
 752             break;
 753          case GL_DECAL:
 754          case GL_REPLACE:
 755             SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
 756             break;
 757          case GL_BLEND:
 758             SPAN_LINEAR(LINEAR_RGB;BLEND,3);
 759             break;
 760          case GL_ADD:
 761             SPAN_LINEAR(LINEAR_RGB;ADD,3);
 762             break;
 763          default:
 764             _mesa_problem(ctx, "bad tex env mode (7) in SPAN_LINEAR");
 765             return;
 766          }
 767          break;
 768       case GL_RGBA:
 769          switch (info->envmode) {
 770          case GL_MODULATE:
 771             SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
 772             break;
 773          case GL_DECAL:
 774             SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
 775             break;
 776          case GL_BLEND:
 777             SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
 778             break;
 779          case GL_ADD:
 780             SPAN_LINEAR(LINEAR_RGBA;ADD,4);
 781             break;
 782          case GL_REPLACE:
 783             SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
 784             break;
 785          default:
 786             _mesa_problem(ctx, "bad tex env mode (8) in SPAN_LINEAR");
 787             return;
 788          }
 789          break;
 790       }
 791       break;
 792    }
 793
 794    ASSERT(span->arrayMask & SPAN_RGBA);
 795    _swrast_write_rgba_span(ctx, span);
 796
 797 #undef SPAN_NEAREST
 798 #undef SPAN_LINEAR
 799
 800    /* restore state */
 801    ctx->Texture._EnabledUnits = savedTexEnable;
 802 }
 803
 804
 805 /*
 806  * Render an perspective corrected RGB/RGBA textured triangle.
 807  * The Q (aka V in Mesa) coordinate must be zero such that the divide
 808  * by interpolated Q/W comes out right.
 809  *
 810  */
 811 #define NAME persp_textured_triangle
 812 #define INTERP_Z 1
 813 #define INTERP_W 1
 814 #define INTERP_FOG 1
 815 #define INTERP_RGB 1
 816 #define INTERP_ALPHA 1
 817 #define INTERP_TEX 1
 818
 819 #define SETUP_CODE                                                      \
 820    struct persp_info info;                                              \
 821    const struct gl_texture_unit *unit = ctx->Texture.Unit+0;            \
 822    const struct gl_texture_object *obj = unit->Current2D;               \
 823    const GLint b = obj->BaseLevel;                                      \
 824    info.texture = (const GLchan *) obj->Image[0][b]->Data;              \
 825    info.twidth_log2 = obj->Image[0][b]->WidthLog2;                      \
 826    info.smask = obj->Image[0][b]->Width - 1;                            \
 827    info.tmask = obj->Image[0][b]->Height - 1;                           \
 828    info.format = obj->Image[0][b]->Format;                              \
 829    info.filter = obj->MinFilter;                                        \
 830    info.envmode = unit->EnvMode;                                        \
 831                                                                         \
 832    if (info.envmode == GL_BLEND) {                                      \
 833       /* potential off-by-one error here? (1.0f -> 2048 -> 0) */        \
 834       info.er = FloatToFixed(unit->EnvColor[RCOMP] * CHAN_MAXF);        \
 835       info.eg = FloatToFixed(unit->EnvColor[GCOMP] * CHAN_MAXF);        \
 836       info.eb = FloatToFixed(unit->EnvColor[BCOMP] * CHAN_MAXF);        \
 837       info.ea = FloatToFixed(unit->EnvColor[ACOMP] * CHAN_MAXF);        \
 838    }                                                                    \
 839    if (!info.texture) {                                                 \
 840       /* this shouldn't happen */                                       \
 841       return;                                                           \
 842    }                                                                    \
 843                                                                         \
 844    switch (info.format) {                                               \
 845    case GL_ALPHA:                                                       \
 846    case GL_LUMINANCE:                                                   \
 847    case GL_INTENSITY:                                                   \
 848       info.tbytesline = obj->Image[0][b]->Width;                        \
 849       break;                                                            \
 850    case GL_LUMINANCE_ALPHA:                                             \
 851       info.tbytesline = obj->Image[0][b]->Width * 2;                    \
 852       break;                                                            \
 853    case GL_RGB:                                                         \
 854       info.tbytesline = obj->Image[0][b]->Width * 3;                    \
 855       break;                                                            \
 856    case GL_RGBA:                                                        \
 857       info.tbytesline = obj->Image[0][b]->Width * 4;                    \
 858       break;                                                            \
 859    default:                                                             \
 860       _mesa_problem(NULL, "Bad texture format in persp_textured_triangle");\
 861       return;                                                           \
 862    }                                                                    \
 863    info.tsize = obj->Image[0][b]->Height * info.tbytesline;
 864
 865 #define RENDER_SPAN( span )                     \
 866    span.interpMask &= ~SPAN_RGBA;               \
 867    span.arrayMask |= SPAN_RGBA;                 \
 868    fast_persp_span(ctx, &span, &info);
 869
 870 #include "s_tritemp.h"
 871
 872
 873 #endif /* CHAN_BITS != GL_FLOAT */
 874
 875
 876
 877
 878 /*
 879  * Render a smooth-shaded, textured, RGBA triangle.
 880  * Interpolate S,T,R with perspective correction, w/out mipmapping.
 881  */
 882 #define NAME general_textured_triangle
 883 #define INTERP_Z 1
 884 #define INTERP_W 1
 885 #define INTERP_FOG 1
 886 #define INTERP_RGB 1
 887 #define INTERP_SPEC 1
 888 #define INTERP_ALPHA 1
 889 #define INTERP_TEX 1
 890 #define RENDER_SPAN( span )   _swrast_write_rgba_span(ctx, &span);
 891 #include "s_tritemp.h"
 892
 893
 894
 895 /*
 896  * This is the big one!
 897  * Interpolate Z, RGB, Alpha, specular, fog, and N sets of texture coordinates.
 898  * Yup, it's slow.
 899  */
 900 #define NAME multitextured_triangle
 901 #define INTERP_Z 1
 902 #define INTERP_W 1
 903 #define INTERP_FOG 1
 904 #define INTERP_RGB 1
 905 #define INTERP_ALPHA 1
 906 #define INTERP_SPEC 1
 907 #define INTERP_MULTITEX 1
 908 #define RENDER_SPAN( span )   _swrast_write_rgba_span(ctx, &span);
 909 #include "s_tritemp.h"
 910
 911
 912
 913 /*
 914  * Special tri function for occlusion testing
 915  */
 916 #define NAME occlusion_zless_triangle
 917 #define INTERP_Z 1
 918 #define SETUP_CODE                                              \
 919    struct gl_renderbuffer *rb                                   \
 920       = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer; \
 921    ASSERT(ctx->Depth.Test);                                     \
 922    ASSERT(!ctx->Depth.Mask);                                    \
 923    ASSERT(ctx->Depth.Func == GL_LESS);                          \
 924    if (ctx->OcclusionResult && !ctx->Occlusion.Active) {        \
 925       return;                                                   \
 926    }
 927 #define RENDER_SPAN( span )                                             \
 928    if (ctx->Visual.depthBits <= 16) {                                   \
 929       GLuint i;                                                         \
 930       const GLushort *zRow = (const GLushort *)                         \
 931          rb->GetPointer(ctx, rb, span.x, span.y);                       \
 932       for (i = 0; i < span.end; i++) {                                  \
 933          GLdepth z = FixedToDepth(span.z);                              \
 934          if (z < zRow[i]) {                                             \
 935             ctx->OcclusionResult = GL_TRUE;                             \
 936             ctx->Occlusion.PassedCounter++;                             \
 937          }                                                              \
 938          span.z += span.zStep;                                          \
 939       }                                                                 \
 940    }                                                                    \
 941    else {                                                               \
 942       GLuint i;                                                         \
 943       const GLuint *zRow = (const GLuint *)                             \
 944          rb->GetPointer(ctx, rb, span.x, span.y);                       \
 945       for (i = 0; i < span.end; i++) {                                  \
 946          if ((GLuint)span.z < zRow[i]) {                                \
 947             ctx->OcclusionResult = GL_TRUE;                             \
 948             ctx->Occlusion.PassedCounter++;                             \
 949          }                                                              \
 950          span.z += span.zStep;                                          \
 951       }                                                                 \
 952    }
 953 #include "s_tritemp.h"
 954
 955
 956
 957 static void
 958 nodraw_triangle( GLcontext *ctx,
 959                  const SWvertex *v0,
 960                  const SWvertex *v1,
 961                  const SWvertex *v2 )
 962 {
 963    (void) (ctx && v0 && v1 && v2);
 964 }
 965
 966
 967 /*
 968  * This is used when separate specular color is enabled, but not
 969  * texturing.  We add the specular color to the primary color,
 970  * draw the triangle, then restore the original primary color.
 971  * Inefficient, but seldom needed.
 972  */
 973 void _swrast_add_spec_terms_triangle( GLcontext *ctx,
 974                                       const SWvertex *v0,
 975                                       const SWvertex *v1,
 976                                       const SWvertex *v2 )
 977 {
 978    SWvertex *ncv0 = (SWvertex *)v0; /* drop const qualifier */
 979    SWvertex *ncv1 = (SWvertex *)v1;
 980    SWvertex *ncv2 = (SWvertex *)v2;
 981 #if CHAN_TYPE == GL_FLOAT
 982    GLfloat rSum, gSum, bSum;
 983 #else
 984    GLint rSum, gSum, bSum;
 985 #endif
 986    GLchan c[3][4];
 987    /* save original colors */
 988    COPY_CHAN4( c[0], ncv0->color );
 989    COPY_CHAN4( c[1], ncv1->color );
 990    COPY_CHAN4( c[2], ncv2->color );
 991    /* sum v0 */
 992    rSum = ncv0->color[0] + ncv0->specular[0];
 993    gSum = ncv0->color[1] + ncv0->specular[1];
 994    bSum = ncv0->color[2] + ncv0->specular[2];
 995    ncv0->color[0] = MIN2(rSum, CHAN_MAX);
 996    ncv0->color[1] = MIN2(gSum, CHAN_MAX);
 997    ncv0->color[2] = MIN2(bSum, CHAN_MAX);
 998    /* sum v1 */
 999    rSum = ncv1->color[0] + ncv1->specular[0];
1000    gSum = ncv1->color[1] + ncv1->specular[1];
1001    bSum = ncv1->color[2] + ncv1->specular[2];
1002    ncv1->color[0] = MIN2(rSum, CHAN_MAX);
1003    ncv1->color[1] = MIN2(gSum, CHAN_MAX);
1004    ncv1->color[2] = MIN2(bSum, CHAN_MAX);
1005    /* sum v2 */
1006    rSum = ncv2->color[0] + ncv2->specular[0];
1007    gSum = ncv2->color[1] + ncv2->specular[1];
1008    bSum = ncv2->color[2] + ncv2->specular[2];
1009    ncv2->color[0] = MIN2(rSum, CHAN_MAX);
1010    ncv2->color[1] = MIN2(gSum, CHAN_MAX);
1011    ncv2->color[2] = MIN2(bSum, CHAN_MAX);
1012    /* draw */
1013    SWRAST_CONTEXT(ctx)->SpecTriangle( ctx, ncv0, ncv1, ncv2 );
1014    /* restore original colors */
1015    COPY_CHAN4( ncv0->color, c[0] );
1016    COPY_CHAN4( ncv1->color, c[1] );
1017    COPY_CHAN4( ncv2->color, c[2] );
1018 }
1019
1020
1021
1022 #ifdef DEBUG
1023
1024 /* record the current triangle function name */
1025 const char *_mesa_triFuncName = NULL;
1026
1027 #define USE(triFunc)                            \
1028 do {                                            \
1029     _mesa_triFuncName = #triFunc;               \
1030     /*printf("%s\n", _mesa_triFuncName);*/      \
1031     swrast->Triangle = triFunc;                 \
1032 } while (0)
1033
1034 #else
1035
1036 #define USE(triFunc)  swrast->Triangle = triFunc;
1037
1038 #endif
1039
1040
1041
1042
1043 /*
1044  * Determine which triangle rendering function to use given the current
1045  * rendering context.
1046  *
1047  * Please update the summary flag _SWRAST_NEW_TRIANGLE if you add or
1048  * remove tests to this code.
1049  */
1050 void
1051 _swrast_choose_triangle( GLcontext *ctx )
1052 {
1053    SWcontext *swrast = SWRAST_CONTEXT(ctx);
1054    const GLboolean rgbmode = ctx->Visual.rgbMode;
1055
1056    if (ctx->Polygon.CullFlag &&
1057        ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK) {
1058       USE(nodraw_triangle);
1059       return;
1060    }
1061
1062    if (ctx->RenderMode==GL_RENDER) {
1063
1064       if (ctx->Polygon.SmoothFlag) {
1065          _swrast_set_aa_triangle_function(ctx);
1066          ASSERT(swrast->Triangle);
1067          return;
1068       }
1069
1070       /* special case for occlusion testing */
1071       if ((ctx->Depth.OcclusionTest || ctx->Occlusion.Active) &&
1072           ctx->Depth.Test &&
1073           ctx->Depth.Mask == GL_FALSE &&
1074           ctx->Depth.Func == GL_LESS &&
1075           !ctx->Stencil.Enabled) {
1076          if ((rgbmode &&
1077               ctx->Color.ColorMask[0] == 0 &&
1078               ctx->Color.ColorMask[1] == 0 &&
1079               ctx->Color.ColorMask[2] == 0 &&
1080               ctx->Color.ColorMask[3] == 0)
1081              ||
1082              (!rgbmode && ctx->Color.IndexMask == 0)) {
1083             USE(occlusion_zless_triangle);
1084             return;
1085          }
1086       }
1087
1088       if (ctx->Texture._EnabledCoordUnits || ctx->FragmentProgram._Active) {
1089          /* Ugh, we do a _lot_ of tests to pick the best textured tri func */
1090          const struct gl_texture_object *texObj2D;
1091          const struct gl_texture_image *texImg;
1092          GLenum minFilter, magFilter, envMode;
1093          GLint format;
1094          texObj2D = ctx->Texture.Unit[0].Current2D;
1095          texImg = texObj2D ? texObj2D->Image[0][texObj2D->BaseLevel] : NULL;
1096          format = texImg ? texImg->TexFormat->MesaFormat : -1;
1097          minFilter = texObj2D ? texObj2D->MinFilter : (GLenum) 0;
1098          magFilter = texObj2D ? texObj2D->MagFilter : (GLenum) 0;
1099          envMode = ctx->Texture.Unit[0].EnvMode;
1100
1101          /* First see if we can use an optimized 2-D texture function */
1102          if (ctx->Texture._EnabledCoordUnits == 0x1
1103              && !ctx->FragmentProgram._Active
1104              && ctx->Texture.Unit[0]._ReallyEnabled == TEXTURE_2D_BIT
1105              && texObj2D->WrapS == GL_REPEAT
1106              && texObj2D->WrapT == GL_REPEAT
1107              && texObj2D->_IsPowerOfTwo
1108              && texImg->Border == 0
1109              && texImg->Width == texImg->RowStride
1110              && (format == MESA_FORMAT_RGB || format == MESA_FORMAT_RGBA)
1111              && minFilter == magFilter
1112              && ctx->Light.Model.ColorControl == GL_SINGLE_COLOR
1113              && ctx->Texture.Unit[0].EnvMode != GL_COMBINE_EXT) {
1114             if (ctx->Hint.PerspectiveCorrection==GL_FASTEST) {
1115                if (minFilter == GL_NEAREST
1116                    && format == MESA_FORMAT_RGB
1117                    && (envMode == GL_REPLACE || envMode == GL_DECAL)
1118                    && ((swrast->_RasterMask == (DEPTH_BIT | TEXTURE_BIT)
1119                         && ctx->Depth.Func == GL_LESS
1120                         && ctx->Depth.Mask == GL_TRUE)
1121                        || swrast->_RasterMask == TEXTURE_BIT)
1122                    && ctx->Polygon.StippleFlag == GL_FALSE
1123                    && ctx->Visual.depthBits <= 16) {
1124                   if (swrast->_RasterMask == (DEPTH_BIT | TEXTURE_BIT)) {
1125                      USE(simple_z_textured_triangle);
1126                   }
1127                   else {
1128                      USE(simple_textured_triangle);
1129                   }
1130                }
1131                else {
1132 #if (CHAN_BITS == 16 || CHAN_BITS == 32)
1133                   USE(general_textured_triangle);
1134 #else
1135                   USE(affine_textured_triangle);
1136 #endif
1137                }
1138             }
1139             else {
1140 #if (CHAN_BITS == 16 || CHAN_BITS == 32)
1141                USE(general_textured_triangle);
1142 #else
1143                USE(persp_textured_triangle);
1144 #endif
1145             }
1146          }
1147          else {
1148             /* general case textured triangles */
1149             if (ctx->Texture._EnabledCoordUnits > 1) {
1150                USE(multitextured_triangle);
1151             }
1152             else {
1153                USE(general_textured_triangle);
1154             }
1155          }
1156       }
1157       else {
1158          ASSERT(!ctx->Texture._EnabledCoordUnits);
1159          if (ctx->Light.ShadeModel==GL_SMOOTH) {
1160             /* smooth shaded, no texturing, stippled or some raster ops */
1161             if (rgbmode) {
1162                USE(smooth_rgba_triangle);
1163             }
1164             else {
1165                USE(smooth_ci_triangle);
1166             }
1167          }
1168          else {
1169             /* flat shaded, no texturing, stippled or some raster ops */
1170             if (rgbmode) {
1171                USE(flat_rgba_triangle);
1172             }
1173             else {
1174                USE(flat_ci_triangle);
1175             }
1176          }
1177       }
1178    }
1179    else if (ctx->RenderMode==GL_FEEDBACK) {
1180       USE(_swrast_feedback_triangle);
1181    }
1182    else {
1183       /* GL_SELECT mode */
1184       USE(_swrast_select_triangle);
1185    }
1186 }