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 GLfloat twidth = (GLfloat) texImg->Width;                      \
 131    const GLfloat theight = (GLfloat) texImg->Height;                    \
 132    const GLint twidth_log2 = texImg->WidthLog2;                         \
 133    const GLubyte *texture = (const GLubyte *) texImg->Data;             \
 134    const GLint smask = texImg->Width - 1;                               \
 135    const GLint tmask = texImg->Height - 1;                              \
 136    ASSERT(texImg->TexFormat == MESA_FORMAT_RGB888);                     \
 137    if (!rb || !texture) {                                               \
 138       return;                                                           \
 139    }
 140
 141 #define RENDER_SPAN( span )                                             \
 142    GLuint i;                                                            \
 143    GLubyte rgb[MAX_WIDTH][3];                                           \
 144    span.intTex[0] -= FIXED_HALF; /* off-by-one error? */                \
 145    span.intTex[1] -= FIXED_HALF;                                        \
 146    for (i = 0; i < span.end; i++) {                                     \
 147       GLint s = FixedToInt(span.intTex[0]) & smask;                     \
 148       GLint t = FixedToInt(span.intTex[1]) & tmask;                     \
 149       GLint pos = (t << twidth_log2) + s;                               \
 150       pos = pos + pos + pos;  /* multiply by 3 */                       \
 151       rgb[i][RCOMP] = texture[pos+2];                                   \
 152       rgb[i][GCOMP] = texture[pos+1];                                   \
 153       rgb[i][BCOMP] = texture[pos+0];                                   \
 154       span.intTex[0] += span.intTexStep[0];                             \
 155       span.intTex[1] += span.intTexStep[1];                             \
 156    }                                                                    \
 157    rb->PutRowRGB(ctx, rb, span.end, span.x, span.y, rgb, NULL);
 158
 159 #include "s_tritemp.h"
 160
 161
 162
 163 /*
 164  * Render an RGB, GL_DECAL, textured triangle.
 165  * Interpolate S,T, GL_LESS depth test, w/out mipmapping or
 166  * perspective correction.
 167  * Depth buffer bits must be <= sizeof(DEFAULT_SOFTWARE_DEPTH_TYPE)
 168  *
 169  * No fog.
 170  */
 171 #define NAME simple_z_textured_triangle
 172 #define INTERP_Z 1
 173 #define DEPTH_TYPE DEFAULT_SOFTWARE_DEPTH_TYPE
 174 #define INTERP_INT_TEX 1
 175 #define S_SCALE twidth
 176 #define T_SCALE theight
 177
 178 #define SETUP_CODE                                                      \
 179    struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];  \
 180    const struct gl_texture_object *obj =                                \
 181       ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];                \
 182    const struct gl_texture_image *texImg =                              \
 183        obj->Image[0][obj->BaseLevel];                                   \
 184    const GLfloat twidth = (GLfloat) texImg->Width;                      \
 185    const GLfloat theight = (GLfloat) texImg->Height;                    \
 186    const GLint twidth_log2 = texImg->WidthLog2;                         \
 187    const GLubyte *texture = (const GLubyte *) texImg->Data;             \
 188    const GLint smask = texImg->Width - 1;                               \
 189    const GLint tmask = texImg->Height - 1;                              \
 190    ASSERT(texImg->TexFormat == MESA_FORMAT_RGB888);                     \
 191    if (!rb || !texture) {                                               \
 192       return;                                                           \
 193    }
 194
 195 #define RENDER_SPAN( span )                                             \
 196    GLuint i;                                                            \
 197    GLubyte rgb[MAX_WIDTH][3];                                           \
 198    span.intTex[0] -= FIXED_HALF; /* off-by-one error? */                \
 199    span.intTex[1] -= FIXED_HALF;                                        \
 200    for (i = 0; i < span.end; i++) {                                     \
 201       const GLuint z = FixedToDepth(span.z);                            \
 202       if (z < zRow[i]) {                                                \
 203          GLint s = FixedToInt(span.intTex[0]) & smask;                  \
 204          GLint t = FixedToInt(span.intTex[1]) & tmask;                  \
 205          GLint pos = (t << twidth_log2) + s;                            \
 206          pos = pos + pos + pos;  /* multiply by 3 */                    \
 207          rgb[i][RCOMP] = texture[pos+2];                                \
 208          rgb[i][GCOMP] = texture[pos+1];                                \
 209          rgb[i][BCOMP] = texture[pos+0];                                \
 210          zRow[i] = z;                                                   \
 211          span.array->mask[i] = 1;                                       \
 212       }                                                                 \
 213       else {                                                            \
 214          span.array->mask[i] = 0;                                       \
 215       }                                                                 \
 216       span.intTex[0] += span.intTexStep[0];                             \
 217       span.intTex[1] += span.intTexStep[1];                             \
 218       span.z += span.zStep;                                             \
 219    }                                                                    \
 220    rb->PutRowRGB(ctx, rb, span.end, span.x, span.y, rgb, span.array->mask);
 221
 222 #include "s_tritemp.h"
 223
 224
 225 #if CHAN_TYPE != GL_FLOAT
 226
 227 struct affine_info
 228 {
 229    GLenum filter;
 230    GLenum format;
 231    GLenum envmode;
 232    GLint smask, tmask;
 233    GLint twidth_log2;
 234    const GLchan *texture;
 235    GLfixed er, eg, eb, ea;
 236    GLint tbytesline, tsize;
 237 };
 238
 239
 240 static INLINE GLint
 241 ilerp(GLint t, GLint a, GLint b)
 242 {
 243    return a + ((t * (b - a)) >> FIXED_SHIFT);
 244 }
 245
 246 static INLINE GLint
 247 ilerp_2d(GLint ia, GLint ib, GLint v00, GLint v10, GLint v01, GLint v11)
 248 {
 249    const GLint temp0 = ilerp(ia, v00, v10);
 250    const GLint temp1 = ilerp(ia, v01, v11);
 251    return ilerp(ib, temp0, temp1);
 252 }
 253
 254
 255 /* This function can handle GL_NEAREST or GL_LINEAR sampling of 2D RGB or RGBA
 256  * textures with GL_REPLACE, GL_MODULATE, GL_BLEND, GL_DECAL or GL_ADD
 257  * texture env modes.
 258  */
 259 static INLINE void
 260 affine_span(struct gl_context *ctx, SWspan *span,
 261             struct affine_info *info)
 262 {
 263    GLchan sample[4];  /* the filtered texture sample */
 264    const GLuint texEnableSave = ctx->Texture._EnabledCoordUnits;
 265
 266    /* Instead of defining a function for each mode, a test is done
 267     * between the outer and inner loops. This is to reduce code size
 268     * and complexity. Observe that an optimizing compiler kills
 269     * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
 270     */
 271
 272 #define NEAREST_RGB             \
 273    sample[RCOMP] = tex00[2];    \
 274    sample[GCOMP] = tex00[1];    \
 275    sample[BCOMP] = tex00[0];    \
 276    sample[ACOMP] = CHAN_MAX;
 277
 278 #define LINEAR_RGB                                                      \
 279    sample[RCOMP] = ilerp_2d(sf, tf, tex00[2], tex01[2], tex10[2], tex11[2]);\
 280    sample[GCOMP] = ilerp_2d(sf, tf, tex00[1], tex01[1], tex10[1], tex11[1]);\
 281    sample[BCOMP] = ilerp_2d(sf, tf, tex00[0], tex01[0], tex10[0], tex11[0]);\
 282    sample[ACOMP] = CHAN_MAX;
 283
 284 #define NEAREST_RGBA  \
 285    sample[RCOMP] = tex00[3];    \
 286    sample[GCOMP] = tex00[2];    \
 287    sample[BCOMP] = tex00[1];    \
 288    sample[ACOMP] = tex00[0];
 289
 290 #define LINEAR_RGBA                                                     \
 291    sample[RCOMP] = ilerp_2d(sf, tf, tex00[3], tex01[3], tex10[3], tex11[3]);\
 292    sample[GCOMP] = ilerp_2d(sf, tf, tex00[2], tex01[2], tex10[2], tex11[2]);\
 293    sample[BCOMP] = ilerp_2d(sf, tf, tex00[1], tex01[1], tex10[1], tex11[1]);\
 294    sample[ACOMP] = ilerp_2d(sf, tf, tex00[0], tex01[0], tex10[0], tex11[0])
 295
 296 #define MODULATE                                                          \
 297    dest[RCOMP] = span->red   * (sample[RCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 298    dest[GCOMP] = span->green * (sample[GCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 299    dest[BCOMP] = span->blue  * (sample[BCOMP] + 1u) >> (FIXED_SHIFT + 8); \
 300    dest[ACOMP] = span->alpha * (sample[ACOMP] + 1u) >> (FIXED_SHIFT + 8)
 301
 302 #define DECAL                                                           \
 303    dest[RCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->red +              \
 304                ((sample[ACOMP] + 1) * sample[RCOMP] << FIXED_SHIFT))    \
 305                >> (FIXED_SHIFT + 8);                                    \
 306    dest[GCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->green +            \
 307                ((sample[ACOMP] + 1) * sample[GCOMP] << FIXED_SHIFT))    \
 308                >> (FIXED_SHIFT + 8);                                    \
 309    dest[BCOMP] = ((CHAN_MAX - sample[ACOMP]) * span->blue +             \
 310                ((sample[ACOMP] + 1) * sample[BCOMP] << FIXED_SHIFT))    \
 311                >> (FIXED_SHIFT + 8);                                    \
 312    dest[ACOMP] = FixedToInt(span->alpha)
 313
 314 #define BLEND                                                           \
 315    dest[RCOMP] = ((CHAN_MAX - sample[RCOMP]) * span->red                \
 316                + (sample[RCOMP] + 1) * info->er) >> (FIXED_SHIFT + 8);  \
 317    dest[GCOMP] = ((CHAN_MAX - sample[GCOMP]) * span->green              \
 318                + (sample[GCOMP] + 1) * info->eg) >> (FIXED_SHIFT + 8);  \
 319    dest[BCOMP] = ((CHAN_MAX - sample[BCOMP]) * span->blue               \
 320                + (sample[BCOMP] + 1) * info->eb) >> (FIXED_SHIFT + 8);  \
 321    dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8)
 322
 323 #define REPLACE  COPY_CHAN4(dest, sample)
 324
 325 #define ADD                                                             \
 326    {                                                                    \
 327       GLint rSum = FixedToInt(span->red)   + (GLint) sample[RCOMP];     \
 328       GLint gSum = FixedToInt(span->green) + (GLint) sample[GCOMP];     \
 329       GLint bSum = FixedToInt(span->blue)  + (GLint) sample[BCOMP];     \
 330       dest[RCOMP] = MIN2(rSum, CHAN_MAX);                               \
 331       dest[GCOMP] = MIN2(gSum, CHAN_MAX);                               \
 332       dest[BCOMP] = MIN2(bSum, CHAN_MAX);                               \
 333       dest[ACOMP] = span->alpha * (sample[ACOMP] + 1) >> (FIXED_SHIFT + 8); \
 334   }
 335
 336 /* shortcuts */
 337
 338 #define NEAREST_RGB_REPLACE             \
 339    NEAREST_RGB;                         \
 340    dest[0] = sample[0];                 \
 341    dest[1] = sample[1];                 \
 342    dest[2] = sample[2];                 \
 343    dest[3] = FixedToInt(span->alpha);
 344
 345 #define NEAREST_RGBA_REPLACE  \
 346    dest[RCOMP] = tex00[3]; \
 347    dest[GCOMP] = tex00[2]; \
 348    dest[BCOMP] = tex00[1]; \
 349    dest[ACOMP] = tex00[0]
 350
 351 #define SPAN_NEAREST(DO_TEX, COMPS)                                     \
 352         for (i = 0; i < span->end; i++) {                               \
 353            /* Isn't it necessary to use FixedFloor below?? */           \
 354            GLint s = FixedToInt(span->intTex[0]) & info->smask;         \
 355            GLint t = FixedToInt(span->intTex[1]) & info->tmask;         \
 356            GLint pos = (t << info->twidth_log2) + s;                    \
 357            const GLchan *tex00 = info->texture + COMPS * pos;           \
 358            DO_TEX;                                                      \
 359            span->red += span->redStep;                                  \
 360            span->green += span->greenStep;                              \
 361            span->blue += span->blueStep;                                \
 362            span->alpha += span->alphaStep;                              \
 363            span->intTex[0] += span->intTexStep[0];                      \
 364            span->intTex[1] += span->intTexStep[1];                      \
 365            dest += 4;                                                   \
 366         }
 367
 368 #define SPAN_LINEAR(DO_TEX, COMPS)                                      \
 369         for (i = 0; i < span->end; i++) {                               \
 370            /* Isn't it necessary to use FixedFloor below?? */           \
 371            const GLint s = FixedToInt(span->intTex[0]) & info->smask;   \
 372            const GLint t = FixedToInt(span->intTex[1]) & info->tmask;   \
 373            const GLfixed sf = span->intTex[0] & FIXED_FRAC_MASK;        \
 374            const GLfixed tf = span->intTex[1] & FIXED_FRAC_MASK;        \
 375            const GLint pos = (t << info->twidth_log2) + s;              \
 376            const GLchan *tex00 = info->texture + COMPS * pos;           \
 377            const GLchan *tex10 = tex00 + info->tbytesline;              \
 378            const GLchan *tex01 = tex00 + COMPS;                         \
 379            const GLchan *tex11 = tex10 + COMPS;                         \
 380            if (t == info->tmask) {                                      \
 381               tex10 -= info->tsize;                                     \
 382               tex11 -= info->tsize;                                     \
 383            }                                                            \
 384            if (s == info->smask) {                                      \
 385               tex01 -= info->tbytesline;                                \
 386               tex11 -= info->tbytesline;                                \
 387            }                                                            \
 388            DO_TEX;                                                      \
 389            span->red += span->redStep;                                  \
 390            span->green += span->greenStep;                              \
 391            span->blue += span->blueStep;                                \
 392            span->alpha += span->alphaStep;                              \
 393            span->intTex[0] += span->intTexStep[0];                      \
 394            span->intTex[1] += span->intTexStep[1];                      \
 395            dest += 4;                                                   \
 396         }
 397
 398
 399    GLuint i;
 400    GLchan *dest = span->array->rgba[0];
 401
 402    /* Disable tex units so they're not re-applied in swrast_write_rgba_span */
 403    ctx->Texture._EnabledCoordUnits = 0x0;
 404
 405    span->intTex[0] -= FIXED_HALF;
 406    span->intTex[1] -= FIXED_HALF;
 407    switch (info->filter) {
 408    case GL_NEAREST:
 409       switch (info->format) {
 410       case MESA_FORMAT_RGB888:
 411          switch (info->envmode) {
 412          case GL_MODULATE:
 413             SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
 414             break;
 415          case GL_DECAL:
 416          case GL_REPLACE:
 417             SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
 418             break;
 419          case GL_BLEND:
 420             SPAN_NEAREST(NEAREST_RGB;BLEND,3);
 421             break;
 422          case GL_ADD:
 423             SPAN_NEAREST(NEAREST_RGB;ADD,3);
 424             break;
 425          default:
 426             _mesa_problem(ctx, "bad tex env mode in SPAN_LINEAR");
 427             return;
 428          }
 429          break;
 430       case MESA_FORMAT_RGBA8888:
 431          switch(info->envmode) {
 432          case GL_MODULATE:
 433             SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
 434             break;
 435          case GL_DECAL:
 436             SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
 437             break;
 438          case GL_BLEND:
 439             SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
 440             break;
 441          case GL_ADD:
 442             SPAN_NEAREST(NEAREST_RGBA;ADD,4);
 443             break;
 444          case GL_REPLACE:
 445             SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
 446             break;
 447          default:
 448             _mesa_problem(ctx, "bad tex env mode (2) in SPAN_LINEAR");
 449             return;
 450          }
 451          break;
 452       }
 453       break;
 454
 455    case GL_LINEAR:
 456       span->intTex[0] -= FIXED_HALF;
 457       span->intTex[1] -= FIXED_HALF;
 458       switch (info->format) {
 459       case MESA_FORMAT_RGB888:
 460          switch (info->envmode) {
 461          case GL_MODULATE:
 462             SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
 463             break;
 464          case GL_DECAL:
 465          case GL_REPLACE:
 466             SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
 467             break;
 468          case GL_BLEND:
 469             SPAN_LINEAR(LINEAR_RGB;BLEND,3);
 470             break;
 471          case GL_ADD:
 472             SPAN_LINEAR(LINEAR_RGB;ADD,3);
 473             break;
 474          default:
 475             _mesa_problem(ctx, "bad tex env mode (3) in SPAN_LINEAR");
 476             return;
 477          }
 478          break;
 479       case MESA_FORMAT_RGBA8888:
 480          switch (info->envmode) {
 481          case GL_MODULATE:
 482             SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
 483             break;
 484          case GL_DECAL:
 485             SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
 486             break;
 487          case GL_BLEND:
 488             SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
 489             break;
 490          case GL_ADD:
 491             SPAN_LINEAR(LINEAR_RGBA;ADD,4);
 492             break;
 493          case GL_REPLACE:
 494             SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
 495             break;
 496          default:
 497             _mesa_problem(ctx, "bad tex env mode (4) in SPAN_LINEAR");
 498             return;
 499          }
 500          break;
 501       }
 502       break;
 503    }
 504    span->interpMask &= ~SPAN_RGBA;
 505    ASSERT(span->arrayMask & SPAN_RGBA);
 506
 507    _swrast_write_rgba_span(ctx, span);
 508
 509    /* re-enable texture units */
 510    ctx->Texture._EnabledCoordUnits = texEnableSave;
 511
 512 #undef SPAN_NEAREST
 513 #undef SPAN_LINEAR
 514 }
 515
 516
 517
 518 /*
 519  * Render an RGB/RGBA textured triangle without perspective correction.
 520  */
 521 #define NAME affine_textured_triangle
 522 #define INTERP_Z 1
 523 #define INTERP_RGB 1
 524 #define INTERP_ALPHA 1
 525 #define INTERP_INT_TEX 1
 526 #define S_SCALE twidth
 527 #define T_SCALE theight
 528
 529 #define SETUP_CODE                                                      \
 530    struct affine_info info;                                             \
 531    struct gl_texture_unit *unit = ctx->Texture.Unit+0;                  \
 532    const struct gl_texture_object *obj =                                \
 533       ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];                \
 534    const struct gl_texture_image *texImg =                              \
 535       obj->Image[0][obj->BaseLevel];                                    \
 536    const GLfloat twidth = (GLfloat) texImg->Width;                      \
 537    const GLfloat theight = (GLfloat) texImg->Height;                    \
 538    info.texture = (const GLchan *) texImg->Data;                        \
 539    info.twidth_log2 = texImg->WidthLog2;                                \
 540    info.smask = texImg->Width - 1;                                      \
 541    info.tmask = texImg->Height - 1;                                     \
 542    info.format = texImg->TexFormat;                                     \
 543    info.filter = obj->Sampler.MinFilter;                                \
 544    info.envmode = unit->EnvMode;                                        \
 545    info.er = 0;                                 \
 546    info.eg = 0;                                 \
 547    info.eb = 0;                                 \
 548    span.arrayMask |= SPAN_RGBA;                                         \
 549                                                                         \
 550    if (info.envmode == GL_BLEND) {                                      \
 551       /* potential off-by-one error here? (1.0f -> 2048 -> 0) */        \
 552       info.er = FloatToFixed(unit->EnvColor[RCOMP] * CHAN_MAXF);        \
 553       info.eg = FloatToFixed(unit->EnvColor[GCOMP] * CHAN_MAXF);        \
 554       info.eb = FloatToFixed(unit->EnvColor[BCOMP] * CHAN_MAXF);        \
 555       info.ea = FloatToFixed(unit->EnvColor[ACOMP] * CHAN_MAXF);        \
 556    }                                                                    \
 557    if (!info.texture) {                                                 \
 558       /* this shouldn't happen */                                       \
 559       return;                                                           \
 560    }                                                                    \
 561                                                                         \
 562    switch (info.format) {                                               \
 563    case MESA_FORMAT_RGB888:                                             \
 564       info.tbytesline = texImg->Width * 3;                              \
 565       break;                                                            \
 566    case MESA_FORMAT_RGBA8888:                                           \
 567       info.tbytesline = texImg->Width * 4;                              \
 568       break;                                                            \
 569    default:                                                             \
 570       _mesa_problem(NULL, "Bad texture format in affine_texture_triangle");\
 571       return;                                                           \
 572    }                                                                    \
 573    info.tsize = texImg->Height * info.tbytesline;
 574
 575 #define RENDER_SPAN( span )   affine_span(ctx, &span, &info);
 576
 577 #include "s_tritemp.h"
 578
 579
 580
 581 struct persp_info
 582 {
 583    GLenum filter;
 584    GLenum format;
 585    GLenum envmode;
 586    GLint smask, tmask;
 587    GLint twidth_log2;
 588    const GLchan *texture;
 589    GLfixed er, eg, eb, ea;   /* texture env color */
 590    GLint tbytesline, tsize;
 591 };
 592
 593
 594 static INLINE void
 595 fast_persp_span(struct gl_context *ctx, SWspan *span,
 596                 struct persp_info *info)
 597 {
 598    GLchan sample[4];  /* the filtered texture sample */
 599
 600   /* Instead of defining a function for each mode, a test is done
 601    * between the outer and inner loops. This is to reduce code size
 602    * and complexity. Observe that an optimizing compiler kills
 603    * unused variables (for instance tf,sf,ti,si in case of GL_NEAREST).
 604    */
 605 #define SPAN_NEAREST(DO_TEX,COMP)                                       \
 606         for (i = 0; i < span->end; i++) {                               \
 607            GLdouble invQ = tex_coord[2] ?                               \
 608                                  (1.0 / tex_coord[2]) : 1.0;            \
 609            GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);             \
 610            GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);             \
 611            GLint s = IFLOOR(s_tmp) & info->smask;                       \
 612            GLint t = IFLOOR(t_tmp) & info->tmask;                       \
 613            GLint pos = (t << info->twidth_log2) + s;                    \
 614            const GLchan *tex00 = info->texture + COMP * pos;            \
 615            DO_TEX;                                                      \
 616            span->red += span->redStep;                                  \
 617            span->green += span->greenStep;                              \
 618            span->blue += span->blueStep;                                \
 619            span->alpha += span->alphaStep;                              \
 620            tex_coord[0] += tex_step[0];                                 \
 621            tex_coord[1] += tex_step[1];                                 \
 622            tex_coord[2] += tex_step[2];                                 \
 623            dest += 4;                                                   \
 624         }
 625
 626 #define SPAN_LINEAR(DO_TEX,COMP)                                        \
 627         for (i = 0; i < span->end; i++) {                               \
 628            GLdouble invQ = tex_coord[2] ?                               \
 629                                  (1.0 / tex_coord[2]) : 1.0;            \
 630            const GLfloat s_tmp = (GLfloat) (tex_coord[0] * invQ);       \
 631            const GLfloat t_tmp = (GLfloat) (tex_coord[1] * invQ);       \
 632            const GLfixed s_fix = FloatToFixed(s_tmp) - FIXED_HALF;      \
 633            const GLfixed t_fix = FloatToFixed(t_tmp) - FIXED_HALF;      \
 634            const GLint s = FixedToInt(FixedFloor(s_fix)) & info->smask; \
 635            const GLint t = FixedToInt(FixedFloor(t_fix)) & info->tmask; \
 636            const GLfixed sf = s_fix & FIXED_FRAC_MASK;                  \
 637            const GLfixed tf = t_fix & FIXED_FRAC_MASK;                  \
 638            const GLint pos = (t << info->twidth_log2) + s;              \
 639            const GLchan *tex00 = info->texture + COMP * pos;            \
 640            const GLchan *tex10 = tex00 + info->tbytesline;              \
 641            const GLchan *tex01 = tex00 + COMP;                          \
 642            const GLchan *tex11 = tex10 + COMP;                          \
 643            if (t == info->tmask) {                                      \
 644               tex10 -= info->tsize;                                     \
 645               tex11 -= info->tsize;                                     \
 646            }                                                            \
 647            if (s == info->smask) {                                      \
 648               tex01 -= info->tbytesline;                                \
 649               tex11 -= info->tbytesline;                                \
 650            }                                                            \
 651            DO_TEX;                                                      \
 652            span->red   += span->redStep;                                \
 653            span->green += span->greenStep;                              \
 654            span->blue  += span->blueStep;                               \
 655            span->alpha += span->alphaStep;                              \
 656            tex_coord[0] += tex_step[0];                                 \
 657            tex_coord[1] += tex_step[1];                                 \
 658            tex_coord[2] += tex_step[2];                                 \
 659            dest += 4;                                                   \
 660         }
 661
 662    GLuint i;
 663    GLfloat tex_coord[3], tex_step[3];
 664    GLchan *dest = span->array->rgba[0];
 665
 666    const GLuint texEnableSave = ctx->Texture._EnabledCoordUnits;
 667    ctx->Texture._EnabledCoordUnits = 0;
 668
 669    tex_coord[0] = span->attrStart[FRAG_ATTRIB_TEX0][0]  * (info->smask + 1);
 670    tex_step[0] = span->attrStepX[FRAG_ATTRIB_TEX0][0] * (info->smask + 1);
 671    tex_coord[1] = span->attrStart[FRAG_ATTRIB_TEX0][1] * (info->tmask + 1);
 672    tex_step[1] = span->attrStepX[FRAG_ATTRIB_TEX0][1] * (info->tmask + 1);
 673    /* span->attrStart[FRAG_ATTRIB_TEX0][2] only if 3D-texturing, here only 2D */
 674    tex_coord[2] = span->attrStart[FRAG_ATTRIB_TEX0][3];
 675    tex_step[2] = span->attrStepX[FRAG_ATTRIB_TEX0][3];
 676
 677    switch (info->filter) {
 678    case GL_NEAREST:
 679       switch (info->format) {
 680       case MESA_FORMAT_RGB888:
 681          switch (info->envmode) {
 682          case GL_MODULATE:
 683             SPAN_NEAREST(NEAREST_RGB;MODULATE,3);
 684             break;
 685          case GL_DECAL:
 686          case GL_REPLACE:
 687             SPAN_NEAREST(NEAREST_RGB_REPLACE,3);
 688             break;
 689          case GL_BLEND:
 690             SPAN_NEAREST(NEAREST_RGB;BLEND,3);
 691             break;
 692          case GL_ADD:
 693             SPAN_NEAREST(NEAREST_RGB;ADD,3);
 694             break;
 695          default:
 696             _mesa_problem(ctx, "bad tex env mode (5) in SPAN_LINEAR");
 697             return;
 698          }
 699          break;
 700       case MESA_FORMAT_RGBA8888:
 701          switch(info->envmode) {
 702          case GL_MODULATE:
 703             SPAN_NEAREST(NEAREST_RGBA;MODULATE,4);
 704             break;
 705          case GL_DECAL:
 706             SPAN_NEAREST(NEAREST_RGBA;DECAL,4);
 707             break;
 708          case GL_BLEND:
 709             SPAN_NEAREST(NEAREST_RGBA;BLEND,4);
 710             break;
 711          case GL_ADD:
 712             SPAN_NEAREST(NEAREST_RGBA;ADD,4);
 713             break;
 714          case GL_REPLACE:
 715             SPAN_NEAREST(NEAREST_RGBA_REPLACE,4);
 716             break;
 717          default:
 718             _mesa_problem(ctx, "bad tex env mode (6) in SPAN_LINEAR");
 719             return;
 720          }
 721          break;
 722       }
 723       break;
 724
 725    case GL_LINEAR:
 726       switch (info->format) {
 727       case MESA_FORMAT_RGB888:
 728          switch (info->envmode) {
 729          case GL_MODULATE:
 730             SPAN_LINEAR(LINEAR_RGB;MODULATE,3);
 731             break;
 732          case GL_DECAL:
 733          case GL_REPLACE:
 734             SPAN_LINEAR(LINEAR_RGB;REPLACE,3);
 735             break;
 736          case GL_BLEND:
 737             SPAN_LINEAR(LINEAR_RGB;BLEND,3);
 738             break;
 739          case GL_ADD:
 740             SPAN_LINEAR(LINEAR_RGB;ADD,3);
 741             break;
 742          default:
 743             _mesa_problem(ctx, "bad tex env mode (7) in SPAN_LINEAR");
 744             return;
 745          }
 746          break;
 747       case MESA_FORMAT_RGBA8888:
 748          switch (info->envmode) {
 749          case GL_MODULATE:
 750             SPAN_LINEAR(LINEAR_RGBA;MODULATE,4);
 751             break;
 752          case GL_DECAL:
 753             SPAN_LINEAR(LINEAR_RGBA;DECAL,4);
 754             break;
 755          case GL_BLEND:
 756             SPAN_LINEAR(LINEAR_RGBA;BLEND,4);
 757             break;
 758          case GL_ADD:
 759             SPAN_LINEAR(LINEAR_RGBA;ADD,4);
 760             break;
 761          case GL_REPLACE:
 762             SPAN_LINEAR(LINEAR_RGBA;REPLACE,4);
 763             break;
 764          default:
 765             _mesa_problem(ctx, "bad tex env mode (8) in SPAN_LINEAR");
 766             return;
 767          }
 768          break;
 769       }
 770       break;
 771    }
 772
 773    ASSERT(span->arrayMask & SPAN_RGBA);
 774    _swrast_write_rgba_span(ctx, span);
 775
 776 #undef SPAN_NEAREST
 777 #undef SPAN_LINEAR
 778
 779    /* restore state */
 780    ctx->Texture._EnabledCoordUnits = texEnableSave;
 781 }
 782
 783
 784 /*
 785  * Render an perspective corrected RGB/RGBA textured triangle.
 786  * The Q (aka V in Mesa) coordinate must be zero such that the divide
 787  * by interpolated Q/W comes out right.
 788  *
 789  */
 790 #define NAME persp_textured_triangle
 791 #define INTERP_Z 1
 792 #define INTERP_RGB 1
 793 #define INTERP_ALPHA 1
 794 #define INTERP_ATTRIBS 1
 795
 796 #define SETUP_CODE                                                      \
 797    struct persp_info info;                                              \
 798    const struct gl_texture_unit *unit = ctx->Texture.Unit+0;            \
 799    const struct gl_texture_object *obj =                                \
 800       ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];                \
 801    const struct gl_texture_image *texImg =                              \
 802       obj->Image[0][obj->BaseLevel];                                    \
 803    info.texture = (const GLchan *) texImg->Data;                        \
 804    info.twidth_log2 = texImg->WidthLog2;                                \
 805    info.smask = texImg->Width - 1;                                      \
 806    info.tmask = texImg->Height - 1;                                     \
 807    info.format = texImg->TexFormat;                                     \
 808    info.filter = obj->Sampler.MinFilter;                                \
 809    info.envmode = unit->EnvMode;                                        \
 810    info.er = 0;                                 \
 811    info.eg = 0;                                 \
 812    info.eb = 0;                                 \
 813                                                                         \
 814    if (info.envmode == GL_BLEND) {                                      \
 815       /* potential off-by-one error here? (1.0f -> 2048 -> 0) */        \
 816       info.er = FloatToFixed(unit->EnvColor[RCOMP] * CHAN_MAXF);        \
 817       info.eg = FloatToFixed(unit->EnvColor[GCOMP] * CHAN_MAXF);        \
 818       info.eb = FloatToFixed(unit->EnvColor[BCOMP] * CHAN_MAXF);        \
 819       info.ea = FloatToFixed(unit->EnvColor[ACOMP] * CHAN_MAXF);        \
 820    }                                                                    \
 821    if (!info.texture) {                                                 \
 822       /* this shouldn't happen */                                       \
 823       return;                                                           \
 824    }                                                                    \
 825                                                                         \
 826    switch (info.format) {                                               \
 827    case MESA_FORMAT_RGB888:                                             \
 828       info.tbytesline = texImg->Width * 3;                              \
 829       break;                                                            \
 830    case MESA_FORMAT_RGBA8888:                                           \
 831       info.tbytesline = texImg->Width * 4;                              \
 832       break;                                                            \
 833    default:                                                             \
 834       _mesa_problem(NULL, "Bad texture format in persp_textured_triangle");\
 835       return;                                                           \
 836    }                                                                    \
 837    info.tsize = texImg->Height * info.tbytesline;
 838
 839 #define RENDER_SPAN( span )                     \
 840    span.interpMask &= ~SPAN_RGBA;               \
 841    span.arrayMask |= SPAN_RGBA;                 \
 842    fast_persp_span(ctx, &span, &info);
 843
 844 #include "s_tritemp.h"
 845
 846 #endif /*CHAN_TYPE != GL_FLOAT*/
 847
 848
 849
 850 /*
 851  * Render an RGBA triangle with arbitrary attributes.
 852  */
 853 #define NAME general_triangle
 854 #define INTERP_Z 1
 855 #define INTERP_RGB 1
 856 #define INTERP_ALPHA 1
 857 #define INTERP_ATTRIBS 1
 858 #define RENDER_SPAN( span )   _swrast_write_rgba_span(ctx, &span);
 859 #include "s_tritemp.h"
 860
 861
 862
 863
 864 /*
 865  * Special tri function for occlusion testing
 866  */
 867 #define NAME occlusion_zless_triangle
 868 #define INTERP_Z 1
 869 #define SETUP_CODE                                                      \
 870    struct gl_renderbuffer *rb = ctx->DrawBuffer->_DepthBuffer;          \
 871    struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;       \
 872    ASSERT(ctx->Depth.Test);                                             \
 873    ASSERT(!ctx->Depth.Mask);                                            \
 874    ASSERT(ctx->Depth.Func == GL_LESS);                                  \
 875    if (!q) {                                                            \
 876       return;                                                           \
 877    }
 878 #define RENDER_SPAN( span )                                             \
 879    if (rb->Format == MESA_FORMAT_Z16) {                                 \
 880       GLuint i;                                                         \
 881       const GLushort *zRow = (const GLushort *)                         \
 882          rb->GetPointer(ctx, rb, span.x, span.y);                       \
 883       for (i = 0; i < span.end; i++) {                                  \
 884          GLuint z = FixedToDepth(span.z);                               \
 885          if (z < zRow[i]) {                                             \
 886             q->Result++;                                                \
 887          }                                                              \
 888          span.z += span.zStep;                                          \
 889       }                                                                 \
 890    }                                                                    \
 891    else {                                                               \
 892       GLuint i;                                                         \
 893       const GLuint *zRow = (const GLuint *)                             \
 894          rb->GetPointer(ctx, rb, span.x, span.y);                       \
 895       for (i = 0; i < span.end; i++) {                                  \
 896          if ((GLuint)span.z < zRow[i]) {                                \
 897             q->Result++;                                                \
 898          }                                                              \
 899          span.z += span.zStep;                                          \
 900       }                                                                 \
 901    }
 902 #include "s_tritemp.h"
 903
 904
 905
 906 static void
 907 nodraw_triangle( struct gl_context *ctx,
 908                  const SWvertex *v0,
 909                  const SWvertex *v1,
 910                  const SWvertex *v2 )
 911 {
 912    (void) (ctx && v0 && v1 && v2);
 913 }
 914
 915
 916 /*
 917  * This is used when separate specular color is enabled, but not
 918  * texturing.  We add the specular color to the primary color,
 919  * draw the triangle, then restore the original primary color.
 920  * Inefficient, but seldom needed.
 921  */
 922 void
 923 _swrast_add_spec_terms_triangle(struct gl_context *ctx, const SWvertex *v0,
 924                                 const SWvertex *v1, const SWvertex *v2)
 925 {
 926    SWvertex *ncv0 = (SWvertex *)v0; /* drop const qualifier */
 927    SWvertex *ncv1 = (SWvertex *)v1;
 928    SWvertex *ncv2 = (SWvertex *)v2;
 929    GLfloat rSum, gSum, bSum;
 930    GLchan cSave[3][4];
 931
 932    /* save original colors */
 933    COPY_CHAN4( cSave[0], ncv0->color );
 934    COPY_CHAN4( cSave[1], ncv1->color );
 935    COPY_CHAN4( cSave[2], ncv2->color );
 936    /* sum v0 */
 937    rSum = CHAN_TO_FLOAT(ncv0->color[0]) + ncv0->attrib[FRAG_ATTRIB_COL1][0];
 938    gSum = CHAN_TO_FLOAT(ncv0->color[1]) + ncv0->attrib[FRAG_ATTRIB_COL1][1];
 939    bSum = CHAN_TO_FLOAT(ncv0->color[2]) + ncv0->attrib[FRAG_ATTRIB_COL1][2];
 940    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[0], rSum);
 941    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[1], gSum);
 942    UNCLAMPED_FLOAT_TO_CHAN(ncv0->color[2], bSum);
 943    /* sum v1 */
 944    rSum = CHAN_TO_FLOAT(ncv1->color[0]) + ncv1->attrib[FRAG_ATTRIB_COL1][0];
 945    gSum = CHAN_TO_FLOAT(ncv1->color[1]) + ncv1->attrib[FRAG_ATTRIB_COL1][1];
 946    bSum = CHAN_TO_FLOAT(ncv1->color[2]) + ncv1->attrib[FRAG_ATTRIB_COL1][2];
 947    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[0], rSum);
 948    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[1], gSum);
 949    UNCLAMPED_FLOAT_TO_CHAN(ncv1->color[2], bSum);
 950    /* sum v2 */
 951    rSum = CHAN_TO_FLOAT(ncv2->color[0]) + ncv2->attrib[FRAG_ATTRIB_COL1][0];
 952    gSum = CHAN_TO_FLOAT(ncv2->color[1]) + ncv2->attrib[FRAG_ATTRIB_COL1][1];
 953    bSum = CHAN_TO_FLOAT(ncv2->color[2]) + ncv2->attrib[FRAG_ATTRIB_COL1][2];
 954    UNCLAMPED_FLOAT_TO_CHAN(ncv2->color[0], rSum);
 955    UNCLAMPED_FLOAT_TO_CHAN(ncv2->color[1], gSum);
 956    UNCLAMPED_FLOAT_TO_CHAN(ncv2->color[2], bSum);
 957    /* draw */
 958    SWRAST_CONTEXT(ctx)->SpecTriangle( ctx, ncv0, ncv1, ncv2 );
 959    /* restore original colors */
 960    COPY_CHAN4( ncv0->color, cSave[0] );
 961    COPY_CHAN4( ncv1->color, cSave[1] );
 962    COPY_CHAN4( ncv2->color, cSave[2] );
 963 }
 964
 965
 966
 967 #ifdef DEBUG
 968
 969 /* record the current triangle function name */
 970 const char *_mesa_triFuncName = NULL;
 971
 972 #define USE(triFunc)                            \
 973 do {                                            \
 974     _mesa_triFuncName = #triFunc;               \
 975     /*printf("%s\n", _mesa_triFuncName);*/      \
 976     swrast->Triangle = triFunc;                 \
 977 } while (0)
 978
 979 #else
 980
 981 #define USE(triFunc)  swrast->Triangle = triFunc;
 982
 983 #endif
 984
 985
 986
 987
 988 /*
 989  * Determine which triangle rendering function to use given the current
 990  * rendering context.
 991  *
 992  * Please update the summary flag _SWRAST_NEW_TRIANGLE if you add or
 993  * remove tests to this code.
 994  */
 995 void
 996 _swrast_choose_triangle( struct gl_context *ctx )
 997 {
 998    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 999
1000    if (ctx->Polygon.CullFlag &&
1001        ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK) {
1002       USE(nodraw_triangle);
1003       return;
1004    }
1005
1006    if (ctx->RenderMode==GL_RENDER) {
1007
1008       if (ctx->Polygon.SmoothFlag) {
1009          _swrast_set_aa_triangle_function(ctx);
1010          ASSERT(swrast->Triangle);
1011          return;
1012       }
1013
1014       /* special case for occlusion testing */
1015       if (ctx->Query.CurrentOcclusionObject &&
1016           ctx->Depth.Test &&
1017           ctx->Depth.Mask == GL_FALSE &&
1018           ctx->Depth.Func == GL_LESS &&
1019           !ctx->Stencil._Enabled) {
1020          if (ctx->Color.ColorMask[0][0] == 0 &&
1021              ctx->Color.ColorMask[0][1] == 0 &&
1022              ctx->Color.ColorMask[0][2] == 0 &&
1023              ctx->Color.ColorMask[0][3] == 0) {
1024             USE(occlusion_zless_triangle);
1025             return;
1026          }
1027       }
1028
1029       /*
1030        * XXX should examine swrast->_ActiveAttribMask to determine what
1031        * needs to be interpolated.
1032        */
1033       if (ctx->Texture._EnabledCoordUnits ||
1034           ctx->FragmentProgram._Current ||
1035           ctx->ATIFragmentShader._Enabled ||
1036           _mesa_need_secondary_color(ctx) ||
1037           swrast->_FogEnabled) {
1038          /* Ugh, we do a _lot_ of tests to pick the best textured tri func */
1039          const struct gl_texture_object *texObj2D;
1040          const struct gl_texture_image *texImg;
1041          GLenum minFilter, magFilter, envMode;
1042          gl_format format;
1043          texObj2D = ctx->Texture.Unit[0].CurrentTex[TEXTURE_2D_INDEX];
1044
1045          texImg = texObj2D ? texObj2D->Image[0][texObj2D->BaseLevel] : NULL;
1046          format = texImg ? texImg->TexFormat : MESA_FORMAT_NONE;
1047          minFilter = texObj2D ? texObj2D->Sampler.MinFilter : GL_NONE;
1048          magFilter = texObj2D ? texObj2D->Sampler.MagFilter : GL_NONE;
1049          envMode = ctx->Texture.Unit[0].EnvMode;
1050
1051          /* First see if we can use an optimized 2-D texture function */
1052          if (ctx->Texture._EnabledCoordUnits == 0x1
1053              && !ctx->FragmentProgram._Current
1054              && !ctx->ATIFragmentShader._Enabled
1055              && ctx->Texture._EnabledUnits == 0x1
1056              && ctx->Texture.Unit[0]._ReallyEnabled == TEXTURE_2D_BIT
1057              && texObj2D->Sampler.WrapS == GL_REPEAT
1058              && texObj2D->Sampler.WrapT == GL_REPEAT
1059              && texObj2D->_Swizzle == SWIZZLE_NOOP
1060              && texImg->_IsPowerOfTwo
1061              && texImg->Border == 0
1062              && texImg->Width == texImg->RowStride
1063              && (format == MESA_FORMAT_RGB888 || format == MESA_FORMAT_RGBA8888)
1064              && minFilter == magFilter
1065              && ctx->Light.Model.ColorControl == GL_SINGLE_COLOR
1066              && !swrast->_FogEnabled
1067              && ctx->Texture.Unit[0].EnvMode != GL_COMBINE_EXT
1068              && ctx->Texture.Unit[0].EnvMode != GL_COMBINE4_NV) {
1069             if (ctx->Hint.PerspectiveCorrection==GL_FASTEST) {
1070                if (minFilter == GL_NEAREST
1071                    && format == MESA_FORMAT_RGB888
1072                    && (envMode == GL_REPLACE || envMode == GL_DECAL)
1073                    && ((swrast->_RasterMask == (DEPTH_BIT | TEXTURE_BIT)
1074                         && ctx->Depth.Func == GL_LESS
1075                         && ctx->Depth.Mask == GL_TRUE)
1076                        || swrast->_RasterMask == TEXTURE_BIT)
1077                    && ctx->Polygon.StippleFlag == GL_FALSE
1078                    && ctx->DrawBuffer->Visual.depthBits <= 16) {
1079                   if (swrast->_RasterMask == (DEPTH_BIT | TEXTURE_BIT)) {
1080                      USE(simple_z_textured_triangle);
1081                   }
1082                   else {
1083                      USE(simple_textured_triangle);
1084                   }
1085                }
1086                else {
1087 #if CHAN_BITS != 8
1088                   USE(general_triangle);
1089 #else
1090                   if (format == MESA_FORMAT_RGBA8888 && !_mesa_little_endian()) {
1091                      /* We only handle RGBA8888 correctly on little endian
1092                       * in the optimized code above.
1093                       */
1094                      USE(general_triangle);
1095                   }
1096                   else {
1097                      USE(affine_textured_triangle);
1098                  }
1099 #endif
1100                }
1101             }
1102             else {
1103 #if CHAN_BITS != 8
1104                USE(general_triangle);
1105 #else
1106                USE(persp_textured_triangle);
1107 #endif
1108             }
1109          }
1110          else {
1111             /* general case textured triangles */
1112             USE(general_triangle);
1113          }
1114       }
1115       else {
1116          ASSERT(!swrast->_FogEnabled);
1117          ASSERT(!_mesa_need_secondary_color(ctx));
1118          if (ctx->Light.ShadeModel==GL_SMOOTH) {
1119             /* smooth shaded, no texturing, stippled or some raster ops */
1120 #if CHAN_BITS != 8
1121                USE(general_triangle);
1122 #else
1123                USE(smooth_rgba_triangle);
1124 #endif
1125          }
1126          else {
1127             /* flat shaded, no texturing, stippled or some raster ops */
1128 #if CHAN_BITS != 8
1129             USE(general_triangle);
1130 #else
1131             USE(flat_rgba_triangle);
1132 #endif
1133          }
1134       }
1135    }
1136    else if (ctx->RenderMode==GL_FEEDBACK) {
1137       USE(_swrast_feedback_triangle);
1138    }
1139    else {
1140       /* GL_SELECT mode */
1141       USE(_swrast_select_triangle);
1142    }
1143 }