src/mesa/swrast/s_triangle.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.3
   4  *
   5  * Copyright (C) 1999-2007  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 "main/glheader.h"
  33 #include "main/context.h"
  34 #include "main/colormac.h"
  35 #include "main/imports.h"
  36 #include "main/macros.h"
  37 #include "main/mtypes.h"
  38 #include "main/state.h"
  39 #include "program/prog_instruction.h"
  40
  41 #include "s_aatriangle.h"
  42 #include "s_context.h"
  43 #include "s_feedback.h"
  44 #include "s_span.h"
  45 #include "s_triangle.h"
  46
  47
  48 /**
  49  * Test if a triangle should be culled.  Used for feedback and selection mode.
  50  * \return GL_TRUE if the triangle is to be culled, GL_FALSE otherwise.
  51  */
  52 GLboolean
  53 _swrast_culltriangle( struct gl_context *ctx,
  54                       const SWvertex *v0,
  55                       const SWvertex *v1,
  56                       const SWvertex *v2 )
  57 {
  58    SWcontext *swrast = SWRAST_CONTEXT(ctx);
  59    GLfloat ex = v1->attrib[FRAG_ATTRIB_WPOS][0] - v0->attrib[FRAG_ATTRIB_WPOS][0];
  60    GLfloat ey = v1->attrib[FRAG_ATTRIB_WPOS][1] - v0->attrib[FRAG_ATTRIB_WPOS][1];
  61    GLfloat fx = v2->attrib[FRAG_ATTRIB_WPOS][0] - v0->attrib[FRAG_ATTRIB_WPOS][0];
  62    GLfloat fy = v2->attrib[FRAG_ATTRIB_WPOS][1] - v0->attrib[FRAG_ATTRIB_WPOS][1];
  63    GLfloat c = ex*fy-ey*fx;
  64
  65    if (c * swrast->_BackfaceSign * swrast->_BackfaceCullSign <= 0.0F)
  66       return GL_FALSE;
  67
  68    return GL_TRUE;
  69 }
  70
  71
  72
  73 /*
  74  * Render a flat-shaded RGBA triangle.
  75  */
  76 #define NAME flat_rgba_triangle
  77 #define INTERP_Z 1
  78 #define SETUP_CODE                              \
  79    ASSERT(ctx->Texture._EnabledCoordUnits == 0);\
  80    ASSERT(ctx->Light.ShadeModel==GL_FLAT);      \
  81    span.interpMask |= SPAN_RGBA;                \
  82    span.red = ChanToFixed(v2->color[0]);        \
  83    span.green = ChanToFixed(v2->color[1]);      \
  84    span.blue = ChanToFixed(v2->color[2]);       \
  85    span.alpha = ChanToFixed(v2->color[3]);      \
  86    span.redStep = 0;                            \
  87    span.greenStep = 0;                          \
  88    span.blueStep = 0;                           \
  89    span.alphaStep = 0;
  90 #define RENDER_SPAN( span )  _swrast_write_rgba_span(ctx, &span);
  91 #include "s_tritemp.h"
  92
  93
  94
  95 /*
  96  * Render a smooth-shaded RGBA triangle.
  97  */
  98 #define NAME smooth_rgba_triangle
  99 #define INTERP_Z 1
 100 #define INTERP_RGB 1
 101 #define INTERP_ALPHA 1
 102 #define SETUP_CODE                              \
 103    {                                            \
 104       /* texturing must be off */               \
 105       ASSERT(ctx->Texture._EnabledCoordUnits == 0);     \
 106       ASSERT(ctx->Light.ShadeModel==GL_SMOOTH); \
 107    }
 108 #define RENDER_SPAN( span )  _swrast_write_rgba_span(ctx, &span);
 109 #include "s_tritemp.h"
 110
 111
 112
 113 /*
 114  * Render an RGB, GL_DECAL, textured triangle.
 115  * Interpolate S,T only w/out mipmapping or perspective correction.
 116  *
 117  * No fog.  No depth testing.
 118  */
 119 #define NAME simple_textured_triangle
 120 #define INTERP_INT_TEX 1
 121 #define S_SCALE twidth
 122 #define T_SCALE theight
 123
 124 #define SETUP_CODE                                                      \
 125    struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];  \
 126    const struct gl_texture_object *obj =                                \
 127       ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];                \
 128    const struct gl_texture_image *texImg =                              \
 129       obj->Image[0][obj->BaseLevel];                                    \
 130    const struct swrast_texture_image *swImg =                           \
 131       swrast_texture_image_const(texImg);                               \
 132    const GLfloat twidth = (GLfloat) texImg->Width;                      \
 133    const GLfloat theight = (GLfloat) texImg->Height;                    \
 134    const GLint twidth_log2 = texImg->WidthLog2;                         \
 135    const GLubyte *texture = (const GLubyte *) swImg->Data;              \
 136    const GLint smask = texImg->Width - 1;                               \
 137    const GLint tmask = texImg->Height - 1;                              \
 138    ASSERT(texImg->TexFormat == MESA_FORMAT_RGB888);                     \
 139    if (!rb || !texture) {                                               \
 140       return;                                                           \
 141    }
 142
 143 #define RENDER_SPAN( span )                                             \
 144    GLuint i;                                                            \
 145    GLubyte rgba[MAX_WIDTH][4];                                          \
 146    span.intTex[0] -= FIXED_HALF; /* off-by-one error? */                \
 147    span.intTex[1] -= FIXED_HALF;                                        \
 148    for (i = 0; i < span.end; i++) {                                     \
 149       GLint s = FixedToInt(span.intTex[0]) & smask;                     \
 150       GLint t = FixedToInt(span.intTex[1]) & tmask;                     \
 151       GLint pos = (t << twidth_log2) + s;                               \
 152       pos = pos + pos + pos;  /* multiply by 3 */                       \
 153       rgba[i][RCOMP] = texture[pos+2];                                  \
 154       rgba[i][GCOMP] = texture[pos+1];                                  \
 155       rgba[i][BCOMP] = texture[pos+0];                                  \
 156       rgba[i][ACOMP] = 0xff;                                            \
 157       span.intTex[0] += span.intTexStep[0];                             \
 158       span.intTex[1] += span.intTexStep[1];                             \
 159    }                                                                    \
 160    rb->PutRow(ctx, rb, span.end, span.x, span.y, rgba, NULL);
 161
 162 #include "s_tritemp.h"
 163
 164
 165
 166 /*
 167  * Render an RGB, GL_DECAL, textured triangle.
 168  * Interpolate S,T, GL_LESS depth test, w/out mipmapping or
 169  * perspective correction.
 170  * Depth buffer bits must be <= sizeof(DEFAULT_SOFTWARE_DEPTH_TYPE)
 171  *
 172  * No fog.
 173  */
 174 #define NAME simple_z_textured_triangle
 175 #define INTERP_Z 1
 176 #define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 177 #define INTERP_INT_TEX 1
 178 #define S_SCALE twidth
 179 #define T_SCALE theight
 180
 181 #define SETUP_CODE                                                      \
 182    struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];  \
 183    const struct gl_texture_object *obj =                                \
 184       ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];                \
 185    const struct gl_texture_image *texImg =                              \
 186        obj->Image[0][obj->BaseLevel];                                   \
 187    const struct swrast_texture_image *swImg =                           \
 188       swrast_texture_image_const(texImg);                               \
 189    const GLfloat twidth = (GLfloat) texImg->Width;                      \
 190    const GLfloat theight = (GLfloat) texImg->Height;                    \
 191    const GLint twidth_log2 = texImg->WidthLog2;                         \
 192    const GLubyte *texture = (const GLubyte *) swImg->Data;              \
 193    const GLint smask = texImg->Width - 1;                               \
 194    const GLint tmask = texImg->Height - 1;                              \
 195    ASSERT(texImg->TexFormat == MESA_FORMAT_RGB888);                     \
 196    if (!rb || !texture) {                                               \
 197       return;                                                           \
 198    }
 199
 200 #define RENDER_SPAN( span )                                             \
 201    GLuint i;                                                            \
 202    GLubyte rgba[MAX_WIDTH][4];                                          \
 203    span.intTex[0] -= FIXED_HALF; /* off-by-one error? */                \
 204    span.intTex[1] -= FIXED_HALF;                                        \
 205    for (i = 0; i < span.end; i++) {                                     \
 206       const GLuint z = FixedToDepth(span.z);                            \
 207       if (z < zRow[i]) {                                                \
 208          GLint s = FixedToInt(span.intTex[0]) & smask;                  \
 209          GLint t = FixedToInt(span.intTex[1]) & tmask;                  \
 210          GLint pos = (t << twidth_log2) + s;                            \
 211          pos = pos + pos + pos;  /* multiply by 3 */                    \
 212          rgba[i][RCOMP] = texture[pos+2];                               \
 213          rgba[i][GCOMP] = texture[pos+1];                               \
 214          rgba[i][BCOMP] = texture[pos+0];                               \
 215          rgba[i][ACOMP] = 0xff;                                         \
 216          zRow[i] = z;                                                   \
 217          span.array->mask[i] = 1;                                       \
 218       }                                                                 \
 219       else {                                                            \
 220          span.array->mask[i] = 0;                                       \
 221       }                                                                 \
 222       span.intTex[0] += span.intTexStep[0];                             \
 223       span.intTex[1] += span.intTexStep[1];                             \
 224       span.z += span.zStep;                                             \
 225    }                                                                    \
 226    rb->PutRow(ctx, rb, span.end, span.x, span.y, rgba, span.array->mask);
 227
 228 #include "s_tritemp.h"
 229
 230
 231 #if CHAN_TYPE != GL_FLOAT
 232
 233 struct affine_info
 234 {
 235    GLenum filter;
 236    GLenum format;
 237    GLenum envmode;
 238    GLint smask, tmask;
 239    GLint twidth_log2;
 240    const GLchan *texture;
 241    GLfixed er, eg, eb, ea;
 242    GLint tbytesline, tsize;
 243 };
 244
 245
 246 static inline GLint
 247 ilerp(GLint t, GLint a, GLint b)
 248 {
 249    return a + ((t * (b - a)) >> FIXED_SHIFT);
 250 }
 251
 252 static inline GLint
 253 ilerp_2d(GLint ia, GLint ib, GLint v00, GLint v10, GLint v01, GLint v11)
 254 {
 255    const GLint temp0 = ilerp(ia, v00, v10);
 256    const GLint temp1 = ilerp(ia, v01, v11);
 257    return ilerp(ib, temp0, temp1);
 258 }
 259
 260
 261 /* This function can handle GL_NEAREST or GL_LINEAR sampling of 2D RGB or RGBA
 262  * textures with GL_REPLACE, GL_MODULATE, GL_BLEND, GL_DECAL or GL_ADD
 263  * texture env modes.
 264  */
 265 static inline void
 266 affine_span(struct gl_context *ctx, SWspan *span,
 267             struct affine_info *info)
 268 {
 269    GLchan sample[4];  /* the filtered texture sample */
 270    const GLuint texEnableSave = ctx->Texture._EnabledCoordUnits;
 271
 272    /* Instead of defining a function for each mode, a test is done
 273     * between the outer and inner loops. This is to reduce code size
 274     * and complexity. Observe that an optimizing compiler kills
 275     * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
 276     */
 277
 278 #define NEAREST_RGB             \
 279    sample[RCOMP] = tex00[2];    \
 280    sample[GCOMP] = tex00[1];    \
 281    sample[BCOMP] = tex00[0];    \
 282    sample[ACOMP] = CHAN_MAX;
 283
 284 #define LINEAR_RGB                                                      \
 285    sample[RCOMP] = ilerp_2d(sf, tf, tex00[2], tex01[2], tex10[2], tex11[2]);\
 286    sample[GCOMP] = ilerp_2d(sf, tf, tex00[1], tex01[1], tex10[1], tex11[1]);\
 287    sample[BCOMP] = ilerp_2d(sf, tf, tex00[0], tex01[0], tex10[0], tex11[0]);\
 288    sample[ACOMP] = CHAN_MAX;
 289
 290 #define NEAREST_RGBA  \
 291    sample[RCOMP] = tex00[3];    \
 292    sample[GCOMP] = tex00[2];    \
 293    sample[BCOMP] = tex00[1];    \
 294    sample[ACOMP] = tex00[0];
 295
 296 #define LINEAR_RGBA                                                     \
 297    sample[RCOMP] = ilerp_2d(sf, tf, tex00[3], tex01[3], tex10[3], tex11[3]);\
 298    sample[GCOMP] = ilerp_2d(sf, tf, tex00[2], tex01[2], tex10[2], tex11[2]);\
 299    sample[BCOMP] = ilerp_2d(sf, tf, tex00[1], tex01[1], tex10[1], tex11[1]);\
 300    sample[ACOMP] = ilerp_2d(sf, tf, tex00[0], tex01[0], tex10[0], tex11[0])
 301
 302 #define MODULATE                                                          \
 303    dest[RCOMP] = span->red   * (sample[RCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 304    dest[GCOMP] = span->green * (sample[GCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 305    dest[BCOMP] = span->blue  * (sample[BCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 306    dest[ACOMP] = span->alpha * (sample[ACOMP] + 1u) >> (FIXED_SHIFT + 8)
 307
 308 #define DECAL                                                           \
 309    dest[RCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->red +              \
 310                ((sample[ACOMP] + 1) * sample[RCOMP] << FIXED_SHIFT))    \
 311                >> (FIXED_SHIFT + 8);                                    \
 312    dest[GCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->green +            \
 313                ((sample[ACOMP] + 1) * sample[GCOMP] << FIXED_SHIFT))    \
 314                >> (FIXED_SHIFT + 8);                                    \
 315    dest[BCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->blue +             \
 316                ((sample[ACOMP] + 1) * sample[BCOMP] << FIXED_SHIFT))    \
 317                >> (FIXED_SHIFT + 8);                                    \
 318    dest[ACOMP] = FixedToInt(span->alpha)
 319
 320 #define BLEND                                                           \
 321    dest[RCOMP] = ((CHAN_MAX - sample[RCOMP]) * span->red                \
 322                + (sample[RCOMP] + 1) * info->er) >> (FIXED_SHIFT + 8);  \
 323    dest[GCOMP] = ((CHAN_MAX - sample[GCOMP]) * span->green              \
 324                + (sample[GCOMP] + 1) * info->eg) >> (FIXED_SHIFT + 8);  \
 325    dest[BCOMP] = ((CHAN_MAX - sample[BCOMP]) * span->blue               \
 326                + (sample[BCOMP] + 1) * info->eb) >> (FIXED_SHIFT + 8);  \
 327    dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8)
 328
 329 #define REPLACE  COPY_CHAN4(dest, sample)
 330
 331 #define ADD                                                             \
 332    {                                                                    \
 333       GLint rSum = FixedToInt(span->red)   + (GLint) sample[RCOMP];     \
 334       GLint gSum = FixedToInt(span->green) + (GLint) sample[GCOMP];     \
 335       GLint bSum = FixedToInt(span->blue)  + (GLint) sample[BCOMP];     \
 336       dest[RCOMP] = MIN2(rSum, CHAN_MAX);                               \
 337       dest[GCOMP] = MIN2(gSum, CHAN_MAX);                               \
 338       dest[BCOMP] = MIN2(bSum, CHAN_MAX);                               \
 339       dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8); \
 340   }
 341
 342 /* shortcuts */
 343
 344 #define NEAREST_RGB_REPLACE             \
 345    NEAREST_RGB;                         \
 346    dest[0] = sample[0];                 \
 347    dest[1] = sample[1];                 \
 348    dest[2] = sample[2];                 \
 349    dest[3] = FixedToInt(span->alpha);
 350
 351 #define NEAREST_RGBA_REPLACE  \
 352    dest[RCOMP] = tex00[3]; \
 353    dest[GCOMP] = tex00[2]; \
 354    dest[BCOMP] = tex00[1]; \
 355    dest[ACOMP] = tex00[0]
 356
 357 #define SPAN_NEAREST(DO_TEX, COMPS)                                     \
 358         for (i = 0; i < span->end; i++) {                               \
 359            /* Isn't it necessary to use FixedFloor below?? */           \
 360            GLint s = FixedToInt(span->intTex[0]) & info->smask;         \
 361            GLint t = FixedToInt(span->intTex[1]) & info->tmask;         \
 362            GLint pos = (t << info->twidth_log2) + s;                    \
 363            const GLchan *tex00 = info->texture + COMPS * pos;           \
 364            DO_TEX;                                                      \
 365            span->red += span->redStep;                                  \
 366            span->green += span->greenStep;                              \
 367            span->blue += span->blueStep;                                \
 368            span->alpha += span->alphaStep;                              \
 369            span->intTex[0] += span->intTexStep[0];                      \
 370            span->intTex[1] += span->intTexStep[1];                      \
 371            dest += 4;                                                   \
 372         }
 373
 374 #define SPAN_LINEAR(DO_TEX, COMPS)                                      \
 375         for (i = 0; i < span->end; i++) {                               \
 376            /* Isn't it necessary to use FixedFloor below?? */           \
 377            const GLint s = FixedToInt(span->intTex[0]) & info->smask;   \
 378            const GLint t = FixedToInt(span->intTex[1]) & info->tmask;   \
 379            const GLfixed sf = span->intTex[0] & FIXED_FRAC_MASK;        \
 380            const GLfixed tf = span->intTex[1] & FIXED_FRAC_MASK;        \
 381            const GLint pos = (t << info->twidth_log2) + s;              \
 382            const GLchan *tex00 = info->texture + COMPS * pos;           \
 383            const GLchan *tex10 = tex00 + info->tbytesline;              \
 384            const GLchan *tex01 = tex00 + COMPS;                         \
 385            const GLchan *tex11 = tex10 + COMPS;                         \
 386            if (t == info->tmask) {                                      \
 387               tex10 -= info->tsize;                                     \
 388               tex11 -= info->tsize;                                     \
 389            }                                                            \
 390            if (s == info->smask) {                                      \
 391               tex01 -= info->tbytesline;                                \
 392               tex11 -= info->tbytesline;                                \
 393            }                                                            \
 394            DO_TEX;                                                      \
 395            span->red += span->redStep;                                  \
 396            span->green += span->greenStep;                              \
 397            span->blue += span->blueStep;                                \
 398            span->alpha += span->alphaStep;                              \
 399            span->intTex[0] += span->intTexStep[0];                      \
 400            span->intTex[1] += span->intTexStep[1];                      \
 401            dest += 4;                                                   \
 402         }
 403
 404
 405    GLuint i;
 406    GLchan *dest = span->array->rgba[0];
 407
 408    /* Disable tex units so they're not re-applied in swrast_write_rgba_span */
 409    ctx->Texture._EnabledCoordUnits = 0x0;
 410
 411    span->intTex[0] -= FIXED_HALF;
 412    span->intTex[1] -= FIXED_HALF;
 413    switch (info->filter) {
 414    case GL_NEAREST:
 415       switch (info->format) {
 416       case MESA_FORMAT_RGB888:
 417          switch (info->envmode) {
 418          case GL_MODULATE:
 419             SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
 420             break;
 421          case GL_DECAL:
 422          case GL_REPLACE:
 423             SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
 424             break;
 425          case GL_BLEND:
 426             SPAN_NEAREST(NEAREST_RGB;BLEND,3);
 427             break;
 428          case GL_ADD:
 429             SPAN_NEAREST(NEAREST_RGB;ADD,3);
 430             break;
 431          default:
 432             _mesa_problem(ctx, "bad tex env mode in SPAN_LINEAR");
 433             return;
 434          }
 435          break;
 436       case MESA_FORMAT_RGBA8888:
 437          switch(info->envmode) {
 438          case GL_MODULATE:
 439             SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
 440             break;
 441          case GL_DECAL:
 442             SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
 443             break;
 444          case GL_BLEND:
 445             SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
 446             break;
 447          case GL_ADD:
 448             SPAN_NEAREST(NEAREST_RGBA;ADD,4);
 449             break;
 450          case GL_REPLACE:
 451             SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
 452             break;
 453          default:
 454             _mesa_problem(ctx, "bad tex env mode (2) in SPAN_LINEAR");
 455             return;
 456          }
 457          break;
 458       }
 459       break;
 460
 461    case GL_LINEAR:
 462       span->intTex[0] -= FIXED_HALF;
 463       span->intTex[1] -= FIXED_HALF;
 464       switch (info->format) {
 465       case MESA_FORMAT_RGB888:
 466          switch (info->envmode) {
 467          case GL_MODULATE:
 468             SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
 469             break;
 470          case GL_DECAL:
 471          case GL_REPLACE:
 472             SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
 473             break;
 474          case GL_BLEND:
 475             SPAN_LINEAR(LINEAR_RGB;BLEND,3);
 476             break;
 477          case GL_ADD:
 478             SPAN_LINEAR(LINEAR_RGB;ADD,3);
 479             break;
 480          default:
 481             _mesa_problem(ctx, "bad tex env mode (3) in SPAN_LINEAR");
 482             return;
 483          }
 484          break;
 485       case MESA_FORMAT_RGBA8888:
 486          switch (info->envmode) {
 487          case GL_MODULATE:
 488             SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
 489             break;
 490          case GL_DECAL:
 491             SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
 492             break;
 493          case GL_BLEND:
 494             SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
 495             break;
 496          case GL_ADD:
 497             SPAN_LINEAR(LINEAR_RGBA;ADD,4);
 498             break;
 499          case GL_REPLACE:
 500             SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
 501             break;
 502          default:
 503             _mesa_problem(ctx, "bad tex env mode (4) in SPAN_LINEAR");
 504             return;
 505          }
 506          break;
 507       }
 508       break;
 509    }
 510    span->interpMask &= ~SPAN_RGBA;
 511    ASSERT(span->arrayMask & SPAN_RGBA);
 512
 513    _swrast_write_rgba_span(ctx, span);
 514
 515    /* re-enable texture units */
 516    ctx->Texture._EnabledCoordUnits = texEnableSave;
 517
 518 #undef SPAN_NEAREST
 519 #undef SPAN_LINEAR
 520 }
 521
 522
 523
 524 /*
 525  * Render an RGB/RGBA textured triangle without perspective correction.
 526  */
 527 #define NAME affine_textured_triangle
 528 #define INTERP_Z 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    const struct gl_texture_object *obj =                                \
 539       ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];                \
 540    const struct gl_texture_image *texImg =                              \
 541       obj->Image[0][obj->BaseLevel];                                    \
 542    const struct swrast_texture_image *swImg =                           \
 543       swrast_texture_image_const(texImg);                               \
 544    const GLfloat twidth = (GLfloat) texImg->Width;                      \
 545    const GLfloat theight = (GLfloat) texImg->Height;                    \
 546    info.texture = (const GLchan *) swImg->Data;                         \
 547    info.twidth_log2 = texImg->WidthLog2;                                \
 548    info.smask = texImg->Width - 1;                                      \
 549    info.tmask = texImg->Height - 1;                                     \
 550    info.format = texImg->TexFormat;                                     \
 551    info.filter = obj->Sampler.MinFilter;                                \
 552    info.envmode = unit->EnvMode;                                        \
 553    info.er = 0;                                 \
 554    info.eg = 0;                                 \
 555    info.eb = 0;                                 \
 556    span.arrayMask |= SPAN_RGBA;                                         \
 557                                                                         \
 558    if (info.envmode == GL_BLEND) {                                      \
 559       /* potential off-by-one error here? (1.0f -> 2048 -> 0) */        \
 560       info.er = FloatToFixed(unit->EnvColor[RCOMP] * CHAN_MAXF);        \
 561       info.eg = FloatToFixed(unit->EnvColor[GCOMP] * CHAN_MAXF);        \
 562       info.eb = FloatToFixed(unit->EnvColor[BCOMP] * CHAN_MAXF);        \
 563       info.ea = FloatToFixed(unit->EnvColor[ACOMP] * CHAN_MAXF);        \
 564    }                                                                    \
 565    if (!info.texture) {                                                 \
 566       /* this shouldn't happen */                                       \
 567       return;                                                           \
 568    }                                                                    \
 569                                                                         \
 570    switch (info.format) {                                               \
 571    case MESA_FORMAT_RGB888:                                             \
 572       info.tbytesline = texImg->Width * 3;                              \
 573       break;                                                            \
 574    case MESA_FORMAT_RGBA8888:                                           \
 575       info.tbytesline = texImg->Width * 4;                              \
 576       break;                                                            \
 577    default:                                                             \
 578       _mesa_problem(NULL, "Bad texture format in affine_texture_triangle");\
 579       return;                                                           \
 580    }                                                                    \
 581    info.tsize = texImg->Height * info.tbytesline;
 582
 583 #define RENDER_SPAN( span )   affine_span(ctx, &span, &info);
 584
 585 #include "s_tritemp.h"
 586
 587
 588
 589 struct persp_info
 590 {
 591    GLenum filter;
 592    GLenum format;
 593    GLenum envmode;
 594    GLint smask, tmask;
 595    GLint twidth_log2;
 596    const GLchan *texture;
 597    GLfixed er, eg, eb, ea;   /* texture env color */
 598    GLint tbytesline, tsize;
 599 };
 600
 601
 602 static inline void
 603 fast_persp_span(struct gl_context *ctx, SWspan *span,
 604                 struct persp_info *info)
 605 {
 606    GLchan sample[4];  /* the filtered texture sample */
 607
 608   /* Instead of defining a function for each mode, a test is done
 609    * between the outer and inner loops. This is to reduce code size
 610    * and complexity. Observe that an optimizing compiler kills
 611    * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
 612    */
 613 #define SPAN_NEAREST(DO_TEX,COMP)                                       \
 614         for (i = 0; i < span->end; i++) {                               \
 615            GLdouble invQ = tex_coord[2] ?                               \
 616                                  (1.0 / tex_coord[2]) : 1.0;            \
 617            GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);             \
 618            GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);             \
 619            GLint s = IFLOOR(s_tmp) & info->smask;                       \
 620            GLint t = IFLOOR(t_tmp) & info->tmask;                       \
 621            GLint pos = (t << info->twidth_log2) + s;                    \
 622            const GLchan *tex00 = info->texture + COMP * pos;            \
 623            DO_TEX;                                                      \
 624            span->red += span->redStep;                                  \
 625            span->green += span->greenStep;                              \
 626            span->blue += span->blueStep;                                \
 627            span->alpha += span->alphaStep;                              \
 628            tex_coord[0] += tex_step[0];                                 \
 629            tex_coord[1] += tex_step[1];                                 \
 630            tex_coord[2] += tex_step[2];                                 \
 631            dest += 4;                                                   \
 632         }
 633
 634 #define SPAN_LINEAR(DO_TEX,COMP)                                        \
 635         for (i = 0; i < span->end; i++) {                               \
 636            GLdouble invQ = tex_coord[2] ?                               \
 637                                  (1.0 / tex_coord[2]) : 1.0;            \
 638            const GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);       \
 639            const GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);       \
 640            const GLfixed s_fix = FloatToFixed(s_tmp) - FIXED_HALF;      \
 641            const GLfixed t_fix = FloatToFixed(t_tmp) - FIXED_HALF;      \
 642            const GLint s = FixedToInt(FixedFloor(s_fix)) & info->smask; \
 643            const GLint t = FixedToInt(FixedFloor(t_fix)) & info->tmask; \
 644            const GLfixed sf = s_fix & FIXED_FRAC_MASK;                  \
 645            const GLfixed tf = t_fix & FIXED_FRAC_MASK;                  \
 646            const GLint pos = (t << info->twidth_log2) + s;              \
 647            const GLchan *tex00 = info->texture + COMP * pos;            \
 648            const GLchan *tex10 = tex00 + info->tbytesline;              \
 649            const GLchan *tex01 = tex00 + COMP;                          \
 650            const GLchan *tex11 = tex10 + COMP;                          \
 651            if (t == info->tmask) {                                      \
 652               tex10 -= info->tsize;                                     \
 653               tex11 -= info->tsize;                                     \
 654            }                                                            \
 655            if (s == info->smask) {                                      \
 656               tex01 -= info->tbytesline;                                \
 657               tex11 -= info->tbytesline;                                \
 658            }                                                            \
 659            DO_TEX;                                                      \
 660            span->red   += span->redStep;                                \
 661            span->green += span->greenStep;                              \
 662            span->blue  += span->blueStep;                               \
 663            span->alpha += span->alphaStep;                              \
 664            tex_coord[0] += tex_step[0];                                 \
 665            tex_coord[1] += tex_step[1];                                 \
 666            tex_coord[2] += tex_step[2];                                 \
 667            dest += 4;                                                   \
 668         }
 669
 670    GLuint i;
 671    GLfloat tex_coord[3], tex_step[3];
 672    GLchan *dest = span->array->rgba[0];
 673
 674    const GLuint texEnableSave = ctx->Texture._EnabledCoordUnits;
 675    ctx->Texture._EnabledCoordUnits = 0;
 676
 677    tex_coord[0] = span->attrStart[FRAG_ATTRIB_TEX0][0]  * (info->smask + 1);
 678    tex_step[0] = span->attrStepX[FRAG_ATTRIB_TEX0][0] * (info->smask + 1);
 679    tex_coord[1] = span->attrStart[FRAG_ATTRIB_TEX0][1] * (info->tmask + 1);
 680    tex_step[1] = span->attrStepX[FRAG_ATTRIB_TEX0][1] * (info->tmask + 1);
 681    /* span->attrStart[FRAG_ATTRIB_TEX0][2] only if 3D-texturing, here only 2D */
 682    tex_coord[2] = span->attrStart[FRAG_ATTRIB_TEX0][3];
 683    tex_step[2] = span->attrStepX[FRAG_ATTRIB_TEX0][3];
 684
 685    switch (info->filter) {
 686    case GL_NEAREST:
 687       switch (info->format) {
 688       case MESA_FORMAT_RGB888:
 689          switch (info->envmode) {
 690          case GL_MODULATE:
 691             SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
 692             break;
 693          case GL_DECAL:
 694          case GL_REPLACE:
 695             SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
 696             break;
 697          case GL_BLEND:
 698             SPAN_NEAREST(NEAREST_RGB;BLEND,3);
 699             break;
 700          case GL_ADD:
 701             SPAN_NEAREST(NEAREST_RGB;ADD,3);
 702             break;
 703          default:
 704             _mesa_problem(ctx, "bad tex env mode (5) in SPAN_LINEAR");
 705             return;
 706          }
 707          break;
 708       case MESA_FORMAT_RGBA8888:
 709          switch(info->envmode) {
 710          case GL_MODULATE:
 711             SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
 712             break;
 713          case GL_DECAL:
 714             SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
 715             break;
 716          case GL_BLEND:
 717             SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
 718             break;
 719          case GL_ADD:
 720             SPAN_NEAREST(NEAREST_RGBA;ADD,4);
 721             break;
 722          case GL_REPLACE:
 723             SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
 724             break;
 725          default:
 726             _mesa_problem(ctx, "bad tex env mode (6) in SPAN_LINEAR");
 727             return;
 728          }
 729          break;
 730       }
 731       break;
 732
 733    case GL_LINEAR:
 734       switch (info->format) {
 735       case MESA_FORMAT_RGB888:
 736          switch (info->envmode) {
 737          case GL_MODULATE:
 738             SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
 739             break;
 740          case GL_DECAL:
 741          case GL_REPLACE:
 742             SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
 743             break;
 744          case GL_BLEND:
 745             SPAN_LINEAR(LINEAR_RGB;BLEND,3);
 746             break;
 747          case GL_ADD:
 748             SPAN_LINEAR(LINEAR_RGB;ADD,3);
 749             break;
 750          default:
 751             _mesa_problem(ctx, "bad tex env mode (7) in SPAN_LINEAR");
 752             return;
 753          }
 754          break;
 755       case MESA_FORMAT_RGBA8888:
 756          switch (info->envmode) {
 757          case GL_MODULATE:
 758             SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
 759             break;
 760          case GL_DECAL:
 761             SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
 762             break;
 763          case GL_BLEND:
 764             SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
 765             break;
 766          case GL_ADD:
 767             SPAN_LINEAR(LINEAR_RGBA;ADD,4);
 768             break;
 769          case GL_REPLACE:
 770             SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
 771             break;
 772          default:
 773             _mesa_problem(ctx, "bad tex env mode (8) in SPAN_LINEAR");
 774             return;
 775          }
 776          break;
 777       }
 778       break;
 779    }
 780
 781    ASSERT(span->arrayMask & SPAN_RGBA);
 782    _swrast_write_rgba_span(ctx, span);
 783
 784 #undef SPAN_NEAREST
 785 #undef SPAN_LINEAR
 786
 787    /* restore state */
 788    ctx->Texture._EnabledCoordUnits = texEnableSave;
 789 }
 790
 791
 792 /*
 793  * Render an perspective corrected RGB/RGBA textured triangle.
 794  * The Q (aka V in Mesa) coordinate must be zero such that the divide
 795  * by interpolated Q/W comes out right.
 796  *
 797  */
 798 #define NAME persp_textured_triangle
 799 #define INTERP_Z 1
 800 #define INTERP_RGB 1
 801 #define INTERP_ALPHA 1
 802 #define INTERP_ATTRIBS 1
 803
 804 #define SETUP_CODE                                                      \
 805    struct persp_info info;                                              \
 806    const struct gl_texture_unit *unit = ctx->Texture.Unit+0;            \
 807    const struct gl_texture_object *obj =                                \
 808       ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];                \
 809    const struct gl_texture_image *texImg =                              \
 810       obj->Image[0][obj->BaseLevel];                                    \
 811    const struct swrast_texture_image *swImg =                           \
 812       swrast_texture_image_const(texImg);                               \
 813    info.texture = (const GLchan *) swImg->Data;                         \
 814    info.twidth_log2 = texImg->WidthLog2;                                \
 815    info.smask = texImg->Width - 1;                                      \
 816    info.tmask = texImg->Height - 1;                                     \
 817    info.format = texImg->TexFormat;                                     \
 818    info.filter = obj->Sampler.MinFilter;                                \
 819    info.envmode = unit->EnvMode;                                        \
 820    info.er = 0;                                 \
 821    info.eg = 0;                                 \
 822    info.eb = 0;                                 \
 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 MESA_FORMAT_RGB888:                                             \
 838       info.tbytesline = texImg->Width * 3;                              \
 839       break;                                                            \
 840    case MESA_FORMAT_RGBA8888:                                           \
 841       info.tbytesline = texImg->Width * 4;                              \
 842       break;                                                            \
 843    default:                                                             \
 844       _mesa_problem(NULL, "Bad texture format in persp_textured_triangle");\
 845       return;                                                           \
 846    }                                                                    \
 847    info.tsize = texImg->Height * info.tbytesline;
 848
 849 #define RENDER_SPAN( span )                     \
 850    span.interpMask &= ~SPAN_RGBA;               \
 851    span.arrayMask |= SPAN_RGBA;                 \
 852    fast_persp_span(ctx, &span, &info);
 853
 854 #include "s_tritemp.h"
 855
 856 #endif /*CHAN_TYPE != GL_FLOAT*/
 857
 858
 859
 860 /*
 861  * Render an RGBA triangle with arbitrary attributes.
 862  */
 863 #define NAME general_triangle
 864 #define INTERP_Z 1
 865 #define INTERP_RGB 1
 866 #define INTERP_ALPHA 1
 867 #define INTERP_ATTRIBS 1
 868 #define RENDER_SPAN( span )   _swrast_write_rgba_span(ctx, &span);
 869 #include "s_tritemp.h"
 870
 871
 872
 873
 874 /*
 875  * Special tri function for occlusion testing
 876  */
 877 #define NAME occlusion_zless_16_triangle
 878 #define INTERP_Z 1
 879 #define SETUP_CODE                                                      \
 880    struct gl_renderbuffer *rb =                                         \
 881       ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;           \
 882    struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;       \
 883    ASSERT(ctx->Depth.Test);                                             \
 884    ASSERT(!ctx->Depth.Mask);                                            \
 885    ASSERT(ctx->Depth.Func == GL_LESS);                                  \
 886    assert(rb->Format == MESA_FORMAT_Z16);                               \
 887    if (!q) {                                                            \
 888       return;                                                           \
 889    }
 890 #define RENDER_SPAN( span )                                             \
 891    {                                                                    \
 892       GLuint i;                                                         \
 893       const GLushort *zRow = (const GLushort *)                         \
 894          _swrast_pixel_address(rb, span.x, span.y);                     \
 895       for (i = 0; i < span.end; i++) {                                  \
 896          GLuint z = FixedToDepth(span.z);                               \
 897          if (z < zRow[i]) {                                             \
 898             q->Result++;                                                \
 899          }                                                              \
 900          span.z += span.zStep;                                          \
 901       }                                                                 \
 902    }
 903 #include "s_tritemp.h"
 904
 905
 906
 907 static void
 908 nodraw_triangle( struct gl_context *ctx,
 909                  const SWvertex *v0,
 910                  const SWvertex *v1,
 911                  const SWvertex *v2 )
 912 {
 913    (void) (ctx && v0 && v1 && v2);
 914 }
 915
 916
 917 /*
 918  * This is used when separate specular color is enabled, but not
 919  * texturing.  We add the specular color to the primary color,
 920  * draw the triangle, then restore the original primary color.
 921  * Inefficient, but seldom needed.
 922  */
 923 void
 924 _swrast_add_spec_terms_triangle(struct gl_context *ctx, const SWvertex *v0,
 925                                 const SWvertex *v1, const SWvertex *v2)
 926 {
 927    SWvertex *ncv0 = (SWvertex *)v0; /* drop const qualifier */
 928    SWvertex *ncv1 = (SWvertex *)v1;
 929    SWvertex *ncv2 = (SWvertex *)v2;
 930    GLfloat rSum, gSum, bSum;
 931    GLchan cSave[3][4];
 932
 933    /* save original colors */
 934    COPY_CHAN4( cSave[0], ncv0->color );
 935    COPY_CHAN4( cSave[1], ncv1->color );
 936    COPY_CHAN4( cSave[2], ncv2->color );
 937    /* sum v0 */
 938    rSum = CHAN_TO_FLOAT(ncv0->color[0]) + ncv0->attrib[FRAG_ATTRIB_COL1][0];
 939    gSum = CHAN_TO_FLOAT(ncv0->color[1]) + ncv0->attrib[FRAG_ATTRIB_COL1][1];
 940    bSum = CHAN_TO_FLOAT(ncv0->color[2]) + ncv0->attrib[FRAG_ATTRIB_COL1][2];
 941    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[0], rSum);
 942    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[1], gSum);
 943    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[2], bSum);
 944    /* sum v1 */
 945    rSum = CHAN_TO_FLOAT(ncv1->color[0]) + ncv1->attrib[FRAG_ATTRIB_COL1][0];
 946    gSum = CHAN_TO_FLOAT(ncv1->color[1]) + ncv1->attrib[FRAG_ATTRIB_COL1][1];
 947    bSum = CHAN_TO_FLOAT(ncv1->color[2]) + ncv1->attrib[FRAG_ATTRIB_COL1][2];
 948    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[0], rSum);
 949    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[1], gSum);
 950    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[2], bSum);
 951    /* sum v2 */
 952    rSum = CHAN_TO_FLOAT(ncv2->color[0]) + ncv2->attrib[FRAG_ATTRIB_COL1][0];
 953    gSum = CHAN_TO_FLOAT(ncv2->color[1]) + ncv2->attrib[FRAG_ATTRIB_COL1][1];
 954    bSum = CHAN_TO_FLOAT(ncv2->color[2]) + ncv2->attrib[FRAG_ATTRIB_COL1][2];
 955    UNCLAMPED_FLOAT_TO_CHAN(ncv2->color[0], rSum);
 956    UNCLAMPED_FLOAT_TO_CHAN(ncv2->color[1], gSum);
 957    UNCLAMPED_FLOAT_TO_CHAN(ncv2->color[2], bSum);
 958    /* draw */
 959    SWRAST_CONTEXT(ctx)->SpecTriangle( ctx, ncv0, ncv1, ncv2 );
 960    /* restore original colors */
 961    COPY_CHAN4( ncv0->color, cSave[0] );
 962    COPY_CHAN4( ncv1->color, cSave[1] );
 963    COPY_CHAN4( ncv2->color, cSave[2] );
 964 }
 965
 966
 967
 968 #ifdef DEBUG
 969
 970 /* record the current triangle function name */
 971 const char *_mesa_triFuncName = NULL;
 972
 973 #define USE(triFunc)                            \
 974 do {                                            \
 975     _mesa_triFuncName = #triFunc;               \
 976     /*printf("%s\n", _mesa_triFuncName);*/      \
 977     swrast->Triangle = triFunc;                 \
 978 } while (0)
 979
 980 #else
 981
 982 #define USE(triFunc)  swrast->Triangle = triFunc;
 983
 984 #endif
 985
 986
 987
 988
 989 /*
 990  * Determine which triangle rendering function to use given the current
 991  * rendering context.
 992  *
 993  * Please update the summary flag _SWRAST_NEW_TRIANGLE if you add or
 994  * remove tests to this code.
 995  */
 996 void
 997 _swrast_choose_triangle( struct gl_context *ctx )
 998 {
 999    SWcontext *swrast = SWRAST_CONTEXT(ctx);
1000
1001    if (ctx->Polygon.CullFlag &&
1002        ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK) {
1003       USE(nodraw_triangle);
1004       return;
1005    }
1006
1007    if (ctx->RenderMode==GL_RENDER) {
1008       struct gl_renderbuffer *depthRb =
1009          ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
1010
1011       if (ctx->Polygon.SmoothFlag) {
1012          _swrast_set_aa_triangle_function(ctx);
1013          ASSERT(swrast->Triangle);
1014          return;
1015       }
1016
1017       /* special case for occlusion testing */
1018       if (ctx->Query.CurrentOcclusionObject &&
1019           ctx->Depth.Test &&
1020           ctx->Depth.Mask == GL_FALSE &&
1021           ctx->Depth.Func == GL_LESS &&
1022           !ctx->Stencil._Enabled &&
1023           depthRb &&
1024           depthRb->Format == MESA_FORMAT_Z16) {
1025          if (ctx->Color.ColorMask[0][0] == 0 &&
1026              ctx->Color.ColorMask[0][1] == 0 &&
1027              ctx->Color.ColorMask[0][2] == 0 &&
1028              ctx->Color.ColorMask[0][3] == 0) {
1029             USE(occlusion_zless_16_triangle);
1030             return;
1031          }
1032       }
1033
1034       /*
1035        * XXX should examine swrast->_ActiveAttribMask to determine what
1036        * needs to be interpolated.
1037        */
1038       if (ctx->Texture._EnabledCoordUnits ||
1039           ctx->FragmentProgram._Current ||
1040           ctx->ATIFragmentShader._Enabled ||
1041           _mesa_need_secondary_color(ctx) ||
1042           swrast->_FogEnabled) {
1043          /* Ugh, we do a _lot_ of tests to pick the best textured tri func */
1044          const struct gl_texture_object *texObj2D;
1045          const struct gl_texture_image *texImg;
1046          const struct swrast_texture_image *swImg;
1047          GLenum minFilter, magFilter, envMode;
1048          gl_format format;
1049          texObj2D = ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];
1050
1051          texImg = texObj2D ? texObj2D->Image[0][texObj2D->BaseLevel] : NULL;
1052          swImg = swrast_texture_image_const(texImg);
1053
1054          format = texImg ? texImg->TexFormat : MESA_FORMAT_NONE;
1055          minFilter = texObj2D ? texObj2D->Sampler.MinFilter : GL_NONE;
1056          magFilter = texObj2D ? texObj2D->Sampler.MagFilter : GL_NONE;
1057          envMode = ctx->Texture.Unit[0].EnvMode;
1058
1059          /* First see if we can use an optimized 2-D texture function */
1060          if (ctx->Texture._EnabledCoordUnits == 0x1
1061              && !ctx->FragmentProgram._Current
1062              && !ctx->ATIFragmentShader._Enabled
1063              && ctx->Texture._EnabledUnits == 0x1
1064              && ctx->Texture.Unit[0]._ReallyEnabled == TEXTURE_2D_BIT
1065              && texObj2D->Sampler.WrapS == GL_REPEAT
1066              && texObj2D->Sampler.WrapT == GL_REPEAT
1067              && texObj2D->_Swizzle == SWIZZLE_NOOP
1068              && swImg->_IsPowerOfTwo
1069              && texImg->Border == 0
1070              && texImg->Width == swImg->RowStride
1071              && (format == MESA_FORMAT_RGB888 || format == MESA_FORMAT_RGBA8888)
1072              && minFilter == magFilter
1073              && ctx->Light.Model.ColorControl == GL_SINGLE_COLOR
1074              && !swrast->_FogEnabled
1075              && ctx->Texture.Unit[0].EnvMode != GL_COMBINE_EXT
1076              && ctx->Texture.Unit[0].EnvMode != GL_COMBINE4_NV) {
1077             if (ctx->Hint.PerspectiveCorrection==GL_FASTEST) {
1078                if (minFilter == GL_NEAREST
1079                    && format == MESA_FORMAT_RGB888
1080                    && (envMode == GL_REPLACE || envMode == GL_DECAL)
1081                    && ((swrast->_RasterMask == (DEPTH_BIT | TEXTURE_BIT)
1082                         && ctx->Depth.Func == GL_LESS
1083                         && ctx->Depth.Mask == GL_TRUE)
1084                        || swrast->_RasterMask == TEXTURE_BIT)
1085                    && ctx->Polygon.StippleFlag == GL_FALSE
1086                    && ctx->DrawBuffer->Visual.depthBits <= 16) {
1087                   if (swrast->_RasterMask == (DEPTH_BIT | TEXTURE_BIT)) {
1088                      USE(simple_z_textured_triangle);
1089                   }
1090                   else {
1091                      USE(simple_textured_triangle);
1092                   }
1093                }
1094                else {
1095 #if CHAN_BITS != 8
1096                   USE(general_triangle);
1097 #else
1098                   if (format == MESA_FORMAT_RGBA8888 && !_mesa_little_endian()) {
1099                      /* We only handle RGBA8888 correctly on little endian
1100                       * in the optimized code above.
1101                       */
1102                      USE(general_triangle);
1103                   }
1104                   else {
1105                      USE(affine_textured_triangle);
1106                  }
1107 #endif
1108                }
1109             }
1110             else {
1111 #if CHAN_BITS != 8
1112                USE(general_triangle);
1113 #else
1114                USE(persp_textured_triangle);
1115 #endif
1116             }
1117          }
1118          else {
1119             /* general case textured triangles */
1120             USE(general_triangle);
1121          }
1122       }
1123       else {
1124          ASSERT(!swrast->_FogEnabled);
1125          ASSERT(!_mesa_need_secondary_color(ctx));
1126          if (ctx->Light.ShadeModel==GL_SMOOTH) {
1127             /* smooth shaded, no texturing, stippled or some raster ops */
1128 #if CHAN_BITS != 8
1129                USE(general_triangle);
1130 #else
1131                USE(smooth_rgba_triangle);
1132 #endif
1133          }
1134          else {
1135             /* flat shaded, no texturing, stippled or some raster ops */
1136 #if CHAN_BITS != 8
1137             USE(general_triangle);
1138 #else
1139             USE(flat_rgba_triangle);
1140 #endif
1141          }
1142       }
1143    }
1144    else if (ctx->RenderMode==GL_FEEDBACK) {
1145       USE(_swrast_feedback_triangle);
1146    }
1147    else {
1148       /* GL_SELECT mode */
1149       USE(_swrast_select_triangle);
1150    }
1151 }