2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2004 Brian Paul All Rights Reserved.
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:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
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.
26 * Triangle Rasterizer Template
28 * This file is #include'd to generate custom triangle rasterizers.
30 * The following macros may be defined to indicate what auxillary information
31 * must be interplated across the triangle:
32 * INTERP_Z - if defined, interpolate Z values
33 * INTERP_FOG - if defined, interpolate fog values
34 * INTERP_RGB - if defined, interpolate RGB values
35 * INTERP_ALPHA - if defined, interpolate Alpha values (req's INTERP_RGB)
36 * INTERP_SPEC - if defined, interpolate specular RGB values
37 * INTERP_INDEX - if defined, interpolate color index values
38 * INTERP_INT_TEX - if defined, interpolate integer ST texcoords
39 * (fast, simple 2-D texture mapping)
40 * INTERP_TEX - if defined, interpolate set 0 float STRQ texcoords
41 * NOTE: OpenGL STRQ = Mesa STUV (R was taken for red)
42 * INTERP_MULTITEX - if defined, interpolate N units of STRQ texcoords
44 * When one can directly address pixels in the color buffer the following
45 * macros can be defined and used to compute pixel addresses during
46 * rasterization (see pRow):
47 * PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint)
48 * BYTES_PER_ROW - number of bytes per row in the color buffer
49 * PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where
50 * Y==0 at bottom of screen and increases upward.
52 * Similarly, for direct depth buffer access, this type is used for depth
54 * DEPTH_TYPE - either GLushort or GLuint
56 * Optionally, one may provide one-time setup code per triangle:
57 * SETUP_CODE - code which is to be executed once per triangle
58 * CLEANUP_CODE - code to execute at end of triangle
60 * The following macro MUST be defined:
61 * RENDER_SPAN(span) - code to write a span of pixels.
63 * This code was designed for the origin to be in the lower-left corner.
65 * Inspired by triangle rasterizer code written by Allen Akin. Thanks Allen!
68 * Some notes on rasterization accuracy:
70 * This code uses fixed point arithmetic (the GLfixed type) to iterate
71 * over the triangle edges and interpolate ancillary data (such as Z,
72 * color, secondary color, etc). The number of fractional bits in
73 * GLfixed and the value of SUB_PIXEL_BITS has a direct bearing on the
74 * accuracy of rasterization.
76 * If SUB_PIXEL_BITS=4 then we'll snap the vertices to the nearest
77 * 1/16 of a pixel. If we're walking up a long, nearly vertical edge
78 * (dx=1/16, dy=1024) we'll need 4 + 10 = 14 fractional bits in
79 * GLfixed to walk the edge without error. If the maximum viewport
80 * height is 4K pixels, then we'll need 4 + 12 = 16 fractional bits.
82 * Historically, Mesa has used 11 fractional bits in GLfixed, snaps
83 * vertices to 1/16 pixel and allowed a maximum viewport height of 2K
84 * pixels. 11 fractional bits is actually insufficient for accurately
85 * rasterizing some triangles. More recently, the maximum viewport
86 * height was increased to 4K pixels. Thus, Mesa should be using 16
87 * fractional bits in GLfixed. Unfortunately, there may be some issues
88 * with setting FIXED_FRAC_BITS=16, such as multiplication overflow.
89 * This will have to be examined in some detail...
91 * For now, if you find rasterization errors, particularly with tall,
92 * sliver triangles, try increasing FIXED_FRAC_BITS and/or decreasing
98 * ColorTemp is used for intermediate color values.
100 #if CHAN_TYPE == GL_FLOAT
101 #define ColorTemp GLfloat
103 #define ColorTemp GLint /* same as GLfixed */
107 * Either loop over all texture units, or just use unit zero.
109 #ifdef INTERP_MULTITEX
110 #define TEX_UNIT_LOOP(CODE) \
113 for (u = 0; u < ctx->Const.MaxTextureUnits; u++) { \
114 if (ctx->Texture._EnabledCoordUnits & (1 << u)) { \
120 #elif defined(INTERP_TEX)
121 #define TEX_UNIT_LOOP(CODE) \
123 const GLuint u = 0; \
129 static void NAME(GLcontext
*ctx
, const SWvertex
*v0
,
134 const SWvertex
*v0
, *v1
; /* Y(v0) < Y(v1) */
135 GLfloat dx
; /* X(v1) - X(v0) */
136 GLfloat dy
; /* Y(v1) - Y(v0) */
137 GLfixed fdxdy
; /* dx/dy in fixed-point */
138 GLfixed fsx
; /* first sample point x coord */
140 GLfloat adjy
; /* adjust from v[0]->fy to fsy, scaled */
141 GLint lines
; /* number of lines to be sampled on this edge */
142 GLfixed fx0
; /* fixed pt X of lower endpoint */
146 const GLint depthBits
= ctx
->Visual
.depthBits
;
147 const GLint fixedToDepthShift
= depthBits
<= 16 ? FIXED_SHIFT
: 0;
148 const GLfloat maxDepth
= ctx
->DepthMaxF
;
149 #define FixedToDepth(F) ((F) >> fixedToDepthShift)
151 EdgeT eMaj
, eTop
, eBot
;
153 const SWvertex
*vMin
, *vMid
, *vMax
; /* Y(vMin)<=Y(vMid)<=Y(vMax) */
154 GLfloat bf
= SWRAST_CONTEXT(ctx
)->_BackfaceSign
;
155 const GLint snapMask
= ~((FIXED_ONE
/ (1 << SUB_PIXEL_BITS
)) - 1); /* for x/y coord snapping */
156 GLfixed vMin_fx
, vMin_fy
, vMid_fx
, vMid_fy
, vMax_fx
, vMax_fy
;
160 INIT_SPAN(span
, GL_POLYGON
, 0, 0, 0);
163 (void) fixedToDepthShift
;
167 printf("%s()\n", __FUNCTION__);
168 printf(" %g, %g, %g\n", v0->win[0], v0->win[1], v0->win[2]);
169 printf(" %g, %g, %g\n", v1->win[0], v1->win[1], v1->win[2]);
170 printf(" %g, %g, %g\n", v2->win[0], v2->win[1], v2->win[2]);
173 /* Compute fixed point x,y coords w/ half-pixel offsets and snapping.
174 * And find the order of the 3 vertices along the Y axis.
177 const GLfixed fy0
= FloatToFixed(v0
->win
[1] - 0.5F
) & snapMask
;
178 const GLfixed fy1
= FloatToFixed(v1
->win
[1] - 0.5F
) & snapMask
;
179 const GLfixed fy2
= FloatToFixed(v2
->win
[1] - 0.5F
) & snapMask
;
184 vMin
= v0
; vMid
= v1
; vMax
= v2
;
185 vMin_fy
= fy0
; vMid_fy
= fy1
; vMax_fy
= fy2
;
187 else if (fy2
<= fy0
) {
189 vMin
= v2
; vMid
= v0
; vMax
= v1
;
190 vMin_fy
= fy2
; vMid_fy
= fy0
; vMax_fy
= fy1
;
194 vMin
= v0
; vMid
= v2
; vMax
= v1
;
195 vMin_fy
= fy0
; vMid_fy
= fy2
; vMax_fy
= fy1
;
202 vMin
= v1
; vMid
= v0
; vMax
= v2
;
203 vMin_fy
= fy1
; vMid_fy
= fy0
; vMax_fy
= fy2
;
206 else if (fy2
<= fy1
) {
208 vMin
= v2
; vMid
= v1
; vMax
= v0
;
209 vMin_fy
= fy2
; vMid_fy
= fy1
; vMax_fy
= fy0
;
214 vMin
= v1
; vMid
= v2
; vMax
= v0
;
215 vMin_fy
= fy1
; vMid_fy
= fy2
; vMax_fy
= fy0
;
219 /* fixed point X coords */
220 vMin_fx
= FloatToFixed(vMin
->win
[0] + 0.5F
) & snapMask
;
221 vMid_fx
= FloatToFixed(vMid
->win
[0] + 0.5F
) & snapMask
;
222 vMax_fx
= FloatToFixed(vMax
->win
[0] + 0.5F
) & snapMask
;
225 /* vertex/edge relationship */
226 eMaj
.v0
= vMin
; eMaj
.v1
= vMax
; /*TODO: .v1's not needed */
227 eTop
.v0
= vMid
; eTop
.v1
= vMax
;
228 eBot
.v0
= vMin
; eBot
.v1
= vMid
;
230 /* compute deltas for each edge: vertex[upper] - vertex[lower] */
231 eMaj
.dx
= FixedToFloat(vMax_fx
- vMin_fx
);
232 eMaj
.dy
= FixedToFloat(vMax_fy
- vMin_fy
);
233 eTop
.dx
= FixedToFloat(vMax_fx
- vMid_fx
);
234 eTop
.dy
= FixedToFloat(vMax_fy
- vMid_fy
);
235 eBot
.dx
= FixedToFloat(vMid_fx
- vMin_fx
);
236 eBot
.dy
= FixedToFloat(vMid_fy
- vMin_fy
);
238 /* compute area, oneOverArea and perform backface culling */
240 const GLfloat area
= eMaj
.dx
* eBot
.dy
- eBot
.dx
* eMaj
.dy
;
242 /* Do backface culling */
246 if (IS_INF_OR_NAN(area
) || area
== 0.0F
)
249 oneOverArea
= 1.0F
/ area
;
252 #ifndef DO_OCCLUSION_TEST
253 ctx
->OcclusionResult
= GL_TRUE
;
255 span
.facing
= ctx
->_Facing
; /* for 2-sided stencil test */
257 /* Edge setup. For a triangle strip these could be reused... */
259 eMaj
.fsy
= FixedCeil(vMin_fy
);
260 eMaj
.lines
= FixedToInt(FixedCeil(vMax_fy
- eMaj
.fsy
));
261 if (eMaj
.lines
> 0) {
262 GLfloat dxdy
= eMaj
.dx
/ eMaj
.dy
;
263 eMaj
.fdxdy
= SignedFloatToFixed(dxdy
);
264 eMaj
.adjy
= (GLfloat
) (eMaj
.fsy
- vMin_fy
); /* SCALED! */
266 eMaj
.fsx
= eMaj
.fx0
+ (GLfixed
) (eMaj
.adjy
* dxdy
);
272 eTop
.fsy
= FixedCeil(vMid_fy
);
273 eTop
.lines
= FixedToInt(FixedCeil(vMax_fy
- eTop
.fsy
));
274 if (eTop
.lines
> 0) {
275 GLfloat dxdy
= eTop
.dx
/ eTop
.dy
;
276 eTop
.fdxdy
= SignedFloatToFixed(dxdy
);
277 eTop
.adjy
= (GLfloat
) (eTop
.fsy
- vMid_fy
); /* SCALED! */
279 eTop
.fsx
= eTop
.fx0
+ (GLfixed
) (eTop
.adjy
* dxdy
);
282 eBot
.fsy
= FixedCeil(vMin_fy
);
283 eBot
.lines
= FixedToInt(FixedCeil(vMid_fy
- eBot
.fsy
));
284 if (eBot
.lines
> 0) {
285 GLfloat dxdy
= eBot
.dx
/ eBot
.dy
;
286 eBot
.fdxdy
= SignedFloatToFixed(dxdy
);
287 eBot
.adjy
= (GLfloat
) (eBot
.fsy
- vMin_fy
); /* SCALED! */
289 eBot
.fsx
= eBot
.fx0
+ (GLfixed
) (eBot
.adjy
* dxdy
);
294 * Conceptually, we view a triangle as two subtriangles
295 * separated by a perfectly horizontal line. The edge that is
296 * intersected by this line is one with maximal absolute dy; we
297 * call it a ``major'' edge. The other two edges are the
298 * ``top'' edge (for the upper subtriangle) and the ``bottom''
299 * edge (for the lower subtriangle). If either of these two
300 * edges is horizontal or very close to horizontal, the
301 * corresponding subtriangle might cover zero sample points;
302 * we take care to handle such cases, for performance as well
305 * By stepping rasterization parameters along the major edge,
306 * we can avoid recomputing them at the discontinuity where
307 * the top and bottom edges meet. However, this forces us to
308 * be able to scan both left-to-right and right-to-left.
309 * Also, we must determine whether the major edge is at the
310 * left or right side of the triangle. We do this by
311 * computing the magnitude of the cross-product of the major
312 * and top edges. Since this magnitude depends on the sine of
313 * the angle between the two edges, its sign tells us whether
314 * we turn to the left or to the right when travelling along
315 * the major edge to the top edge, and from this we infer
316 * whether the major edge is on the left or the right.
318 * Serendipitously, this cross-product magnitude is also a
319 * value we need to compute the iteration parameter
320 * derivatives for the triangle, and it can be used to perform
321 * backface culling because its sign tells us whether the
322 * triangle is clockwise or counterclockwise. In this code we
323 * refer to it as ``area'' because it's also proportional to
324 * the pixel area of the triangle.
328 GLint scan_from_left_to_right
; /* true if scanning left-to-right */
334 * Execute user-supplied setup code
340 scan_from_left_to_right
= (oneOverArea
< 0.0F
);
343 /* compute d?/dx and d?/dy derivatives */
345 span
.interpMask
|= SPAN_Z
;
347 GLfloat eMaj_dz
= vMax
->win
[2] - vMin
->win
[2];
348 GLfloat eBot_dz
= vMid
->win
[2] - vMin
->win
[2];
349 span
.dzdx
= oneOverArea
* (eMaj_dz
* eBot
.dy
- eMaj
.dy
* eBot_dz
);
350 if (span
.dzdx
> maxDepth
|| span
.dzdx
< -maxDepth
) {
351 /* probably a sliver triangle */
356 span
.dzdy
= oneOverArea
* (eMaj
.dx
* eBot_dz
- eMaj_dz
* eBot
.dx
);
359 span
.zStep
= SignedFloatToFixed(span
.dzdx
);
361 span
.zStep
= (GLint
) span
.dzdx
;
366 const GLfloat eMaj_dw
= vMax
->win
[3] - vMin
->win
[3];
367 const GLfloat eBot_dw
= vMid
->win
[3] - vMin
->win
[3];
368 span
.dwdx
= oneOverArea
* (eMaj_dw
* eBot
.dy
- eMaj
.dy
* eBot_dw
);
369 span
.dwdy
= oneOverArea
* (eMaj
.dx
* eBot_dw
- eMaj_dw
* eBot
.dx
);
373 span
.interpMask
|= SPAN_FOG
;
375 const GLfloat eMaj_dfog
= vMax
->fog
- vMin
->fog
;
376 const GLfloat eBot_dfog
= vMid
->fog
- vMin
->fog
;
377 span
.dfogdx
= oneOverArea
* (eMaj_dfog
* eBot
.dy
- eMaj
.dy
* eBot_dfog
);
378 span
.dfogdy
= oneOverArea
* (eMaj
.dx
* eBot_dfog
- eMaj_dfog
* eBot
.dx
);
379 span
.fogStep
= span
.dfogdx
;
383 span
.interpMask
|= SPAN_RGBA
;
384 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
385 GLfloat eMaj_dr
= (GLfloat
) ((ColorTemp
) vMax
->color
[RCOMP
] - vMin
->color
[RCOMP
]);
386 GLfloat eBot_dr
= (GLfloat
) ((ColorTemp
) vMid
->color
[RCOMP
] - vMin
->color
[RCOMP
]);
387 GLfloat eMaj_dg
= (GLfloat
) ((ColorTemp
) vMax
->color
[GCOMP
] - vMin
->color
[GCOMP
]);
388 GLfloat eBot_dg
= (GLfloat
) ((ColorTemp
) vMid
->color
[GCOMP
] - vMin
->color
[GCOMP
]);
389 GLfloat eMaj_db
= (GLfloat
) ((ColorTemp
) vMax
->color
[BCOMP
] - vMin
->color
[BCOMP
]);
390 GLfloat eBot_db
= (GLfloat
) ((ColorTemp
) vMid
->color
[BCOMP
] - vMin
->color
[BCOMP
]);
392 GLfloat eMaj_da
= (GLfloat
) ((ColorTemp
) vMax
->color
[ACOMP
] - vMin
->color
[ACOMP
]);
393 GLfloat eBot_da
= (GLfloat
) ((ColorTemp
) vMid
->color
[ACOMP
] - vMin
->color
[ACOMP
]);
395 span
.drdx
= oneOverArea
* (eMaj_dr
* eBot
.dy
- eMaj
.dy
* eBot_dr
);
396 span
.drdy
= oneOverArea
* (eMaj
.dx
* eBot_dr
- eMaj_dr
* eBot
.dx
);
397 span
.dgdx
= oneOverArea
* (eMaj_dg
* eBot
.dy
- eMaj
.dy
* eBot_dg
);
398 span
.dgdy
= oneOverArea
* (eMaj
.dx
* eBot_dg
- eMaj_dg
* eBot
.dx
);
399 span
.dbdx
= oneOverArea
* (eMaj_db
* eBot
.dy
- eMaj
.dy
* eBot_db
);
400 span
.dbdy
= oneOverArea
* (eMaj
.dx
* eBot_db
- eMaj_db
* eBot
.dx
);
401 # if CHAN_TYPE == GL_FLOAT
402 span
.redStep
= span
.drdx
;
403 span
.greenStep
= span
.dgdx
;
404 span
.blueStep
= span
.dbdx
;
406 span
.redStep
= SignedFloatToFixed(span
.drdx
);
407 span
.greenStep
= SignedFloatToFixed(span
.dgdx
);
408 span
.blueStep
= SignedFloatToFixed(span
.dbdx
);
409 # endif /* GL_FLOAT */
411 span
.dadx
= oneOverArea
* (eMaj_da
* eBot
.dy
- eMaj
.dy
* eBot_da
);
412 span
.dady
= oneOverArea
* (eMaj
.dx
* eBot_da
- eMaj_da
* eBot
.dx
);
413 # if CHAN_TYPE == GL_FLOAT
414 span
.alphaStep
= span
.dadx
;
416 span
.alphaStep
= SignedFloatToFixed(span
.dadx
);
417 # endif /* GL_FLOAT */
418 # endif /* INTERP_ALPHA */
421 ASSERT (ctx
->Light
.ShadeModel
== GL_FLAT
);
422 span
.interpMask
|= SPAN_FLAT
;
423 span
.drdx
= span
.drdy
= 0.0F
;
424 span
.dgdx
= span
.dgdy
= 0.0F
;
425 span
.dbdx
= span
.dbdy
= 0.0F
;
426 # if CHAN_TYPE == GL_FLOAT
428 span
.greenStep
= 0.0F
;
429 span
.blueStep
= 0.0F
;
434 # endif /* GL_FLOAT */
436 span
.dadx
= span
.dady
= 0.0F
;
437 # if CHAN_TYPE == GL_FLOAT
438 span
.alphaStep
= 0.0F
;
441 # endif /* GL_FLOAT */
444 #endif /* INTERP_RGB */
446 span
.interpMask
|= SPAN_SPEC
;
447 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
448 GLfloat eMaj_dsr
= (GLfloat
) ((ColorTemp
) vMax
->specular
[RCOMP
] - vMin
->specular
[RCOMP
]);
449 GLfloat eBot_dsr
= (GLfloat
) ((ColorTemp
) vMid
->specular
[RCOMP
] - vMin
->specular
[RCOMP
]);
450 GLfloat eMaj_dsg
= (GLfloat
) ((ColorTemp
) vMax
->specular
[GCOMP
] - vMin
->specular
[GCOMP
]);
451 GLfloat eBot_dsg
= (GLfloat
) ((ColorTemp
) vMid
->specular
[GCOMP
] - vMin
->specular
[GCOMP
]);
452 GLfloat eMaj_dsb
= (GLfloat
) ((ColorTemp
) vMax
->specular
[BCOMP
] - vMin
->specular
[BCOMP
]);
453 GLfloat eBot_dsb
= (GLfloat
) ((ColorTemp
) vMid
->specular
[BCOMP
] - vMin
->specular
[BCOMP
]);
454 span
.dsrdx
= oneOverArea
* (eMaj_dsr
* eBot
.dy
- eMaj
.dy
* eBot_dsr
);
455 span
.dsrdy
= oneOverArea
* (eMaj
.dx
* eBot_dsr
- eMaj_dsr
* eBot
.dx
);
456 span
.dsgdx
= oneOverArea
* (eMaj_dsg
* eBot
.dy
- eMaj
.dy
* eBot_dsg
);
457 span
.dsgdy
= oneOverArea
* (eMaj
.dx
* eBot_dsg
- eMaj_dsg
* eBot
.dx
);
458 span
.dsbdx
= oneOverArea
* (eMaj_dsb
* eBot
.dy
- eMaj
.dy
* eBot_dsb
);
459 span
.dsbdy
= oneOverArea
* (eMaj
.dx
* eBot_dsb
- eMaj_dsb
* eBot
.dx
);
460 # if CHAN_TYPE == GL_FLOAT
461 span
.specRedStep
= span
.dsrdx
;
462 span
.specGreenStep
= span
.dsgdx
;
463 span
.specBlueStep
= span
.dsbdx
;
465 span
.specRedStep
= SignedFloatToFixed(span
.dsrdx
);
466 span
.specGreenStep
= SignedFloatToFixed(span
.dsgdx
);
467 span
.specBlueStep
= SignedFloatToFixed(span
.dsbdx
);
471 span
.dsrdx
= span
.dsrdy
= 0.0F
;
472 span
.dsgdx
= span
.dsgdy
= 0.0F
;
473 span
.dsbdx
= span
.dsbdy
= 0.0F
;
474 # if CHAN_TYPE == GL_FLOAT
475 span
.specRedStep
= 0.0F
;
476 span
.specGreenStep
= 0.0F
;
477 span
.specBlueStep
= 0.0F
;
479 span
.specRedStep
= 0;
480 span
.specGreenStep
= 0;
481 span
.specBlueStep
= 0;
484 #endif /* INTERP_SPEC */
486 span
.interpMask
|= SPAN_INDEX
;
487 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
488 GLfloat eMaj_di
= (GLfloat
) ((GLint
) vMax
->index
- (GLint
) vMin
->index
);
489 GLfloat eBot_di
= (GLfloat
) ((GLint
) vMid
->index
- (GLint
) vMin
->index
);
490 didx
= oneOverArea
* (eMaj_di
* eBot
.dy
- eMaj
.dy
* eBot_di
);
491 didy
= oneOverArea
* (eMaj
.dx
* eBot_di
- eMaj_di
* eBot
.dx
);
492 span
.indexStep
= SignedFloatToFixed(didx
);
495 span
.interpMask
|= SPAN_FLAT
;
500 #ifdef INTERP_INT_TEX
501 span
.interpMask
|= SPAN_INT_TEXTURE
;
503 GLfloat eMaj_ds
= (vMax
->texcoord
[0][0] - vMin
->texcoord
[0][0]) * S_SCALE
;
504 GLfloat eBot_ds
= (vMid
->texcoord
[0][0] - vMin
->texcoord
[0][0]) * S_SCALE
;
505 GLfloat eMaj_dt
= (vMax
->texcoord
[0][1] - vMin
->texcoord
[0][1]) * T_SCALE
;
506 GLfloat eBot_dt
= (vMid
->texcoord
[0][1] - vMin
->texcoord
[0][1]) * T_SCALE
;
507 span
.texStepX
[0][0] = oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
508 span
.texStepY
[0][0] = oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
509 span
.texStepX
[0][1] = oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
510 span
.texStepY
[0][1] = oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
511 span
.intTexStep
[0] = SignedFloatToFixed(span
.texStepX
[0][0]);
512 span
.intTexStep
[1] = SignedFloatToFixed(span
.texStepX
[0][1]);
516 span
.interpMask
|= SPAN_TEXTURE
;
519 const GLfloat wMax
= vMax
->win
[3], wMin
= vMin
->win
[3], wMid
= vMid
->win
[3];
521 GLfloat eMaj_ds
= vMax
->texcoord
[u
][0] * wMax
- vMin
->texcoord
[u
][0] * wMin
;
522 GLfloat eBot_ds
= vMid
->texcoord
[u
][0] * wMid
- vMin
->texcoord
[u
][0] * wMin
;
523 GLfloat eMaj_dt
= vMax
->texcoord
[u
][1] * wMax
- vMin
->texcoord
[u
][1] * wMin
;
524 GLfloat eBot_dt
= vMid
->texcoord
[u
][1] * wMid
- vMin
->texcoord
[u
][1] * wMin
;
525 GLfloat eMaj_du
= vMax
->texcoord
[u
][2] * wMax
- vMin
->texcoord
[u
][2] * wMin
;
526 GLfloat eBot_du
= vMid
->texcoord
[u
][2] * wMid
- vMin
->texcoord
[u
][2] * wMin
;
527 GLfloat eMaj_dv
= vMax
->texcoord
[u
][3] * wMax
- vMin
->texcoord
[u
][3] * wMin
;
528 GLfloat eBot_dv
= vMid
->texcoord
[u
][3] * wMid
- vMin
->texcoord
[u
][3] * wMin
;
529 span
.texStepX
[u
][0] = oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
530 span
.texStepY
[u
][0] = oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
531 span
.texStepX
[u
][1] = oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
532 span
.texStepY
[u
][1] = oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
533 span
.texStepX
[u
][2] = oneOverArea
* (eMaj_du
* eBot
.dy
- eMaj
.dy
* eBot_du
);
534 span
.texStepY
[u
][2] = oneOverArea
* (eMaj
.dx
* eBot_du
- eMaj_du
* eBot
.dx
);
535 span
.texStepX
[u
][3] = oneOverArea
* (eMaj_dv
* eBot
.dy
- eMaj
.dy
* eBot_dv
);
536 span
.texStepY
[u
][3] = oneOverArea
* (eMaj
.dx
* eBot_dv
- eMaj_dv
* eBot
.dx
);
542 * We always sample at pixel centers. However, we avoid
543 * explicit half-pixel offsets in this code by incorporating
544 * the proper offset in each of x and y during the
545 * transformation to window coordinates.
547 * We also apply the usual rasterization rules to prevent
548 * cracks and overlaps. A pixel is considered inside a
549 * subtriangle if it meets all of four conditions: it is on or
550 * to the right of the left edge, strictly to the left of the
551 * right edge, on or below the top edge, and strictly above
552 * the bottom edge. (Some edges may be degenerate.)
554 * The following discussion assumes left-to-right scanning
555 * (that is, the major edge is on the left); the right-to-left
556 * case is a straightforward variation.
558 * We start by finding the half-integral y coordinate that is
559 * at or below the top of the triangle. This gives us the
560 * first scan line that could possibly contain pixels that are
561 * inside the triangle.
563 * Next we creep down the major edge until we reach that y,
564 * and compute the corresponding x coordinate on the edge.
565 * Then we find the half-integral x that lies on or just
566 * inside the edge. This is the first pixel that might lie in
567 * the interior of the triangle. (We won't know for sure
568 * until we check the other edges.)
570 * As we rasterize the triangle, we'll step down the major
571 * edge. For each step in y, we'll move an integer number
572 * of steps in x. There are two possible x step sizes, which
573 * we'll call the ``inner'' step (guaranteed to land on the
574 * edge or inside it) and the ``outer'' step (guaranteed to
575 * land on the edge or outside it). The inner and outer steps
576 * differ by one. During rasterization we maintain an error
577 * term that indicates our distance from the true edge, and
578 * select either the inner step or the outer step, whichever
579 * gets us to the first pixel that falls inside the triangle.
581 * All parameters (z, red, etc.) as well as the buffer
582 * addresses for color and z have inner and outer step values,
583 * so that we can increment them appropriately. This method
584 * eliminates the need to adjust parameters by creeping a
585 * sub-pixel amount into the triangle at each scanline.
590 GLfixed fxLeftEdge
= 0, fxRightEdge
= 0;
591 GLfixed fdxLeftEdge
= 0, fdxRightEdge
= 0;
592 GLfixed fError
= 0, fdError
= 0;
594 PIXEL_TYPE
*pRow
= NULL
;
595 GLint dPRowOuter
= 0, dPRowInner
; /* offset in bytes */
599 DEPTH_TYPE
*zRow
= NULL
;
600 GLint dZRowOuter
= 0, dZRowInner
; /* offset in bytes */
602 GLfixed zLeft
= 0, fdzOuter
= 0, fdzInner
;
605 GLfloat wLeft
= 0, dwOuter
= 0, dwInner
;
608 GLfloat fogLeft
= 0, dfogOuter
= 0, dfogInner
;
611 ColorTemp rLeft
= 0, fdrOuter
= 0, fdrInner
;
612 ColorTemp gLeft
= 0, fdgOuter
= 0, fdgInner
;
613 ColorTemp bLeft
= 0, fdbOuter
= 0, fdbInner
;
616 ColorTemp aLeft
= 0, fdaOuter
= 0, fdaInner
;
619 ColorTemp srLeft
=0, dsrOuter
=0, dsrInner
;
620 ColorTemp sgLeft
=0, dsgOuter
=0, dsgInner
;
621 ColorTemp sbLeft
=0, dsbOuter
=0, dsbInner
;
624 GLfixed iLeft
=0, diOuter
=0, diInner
;
626 #ifdef INTERP_INT_TEX
627 GLfixed sLeft
=0, dsOuter
=0, dsInner
;
628 GLfixed tLeft
=0, dtOuter
=0, dtInner
;
631 GLfloat sLeft
[MAX_TEXTURE_COORD_UNITS
];
632 GLfloat tLeft
[MAX_TEXTURE_COORD_UNITS
];
633 GLfloat uLeft
[MAX_TEXTURE_COORD_UNITS
];
634 GLfloat vLeft
[MAX_TEXTURE_COORD_UNITS
];
635 GLfloat dsOuter
[MAX_TEXTURE_COORD_UNITS
], dsInner
[MAX_TEXTURE_COORD_UNITS
];
636 GLfloat dtOuter
[MAX_TEXTURE_COORD_UNITS
], dtInner
[MAX_TEXTURE_COORD_UNITS
];
637 GLfloat duOuter
[MAX_TEXTURE_COORD_UNITS
], duInner
[MAX_TEXTURE_COORD_UNITS
];
638 GLfloat dvOuter
[MAX_TEXTURE_COORD_UNITS
], dvInner
[MAX_TEXTURE_COORD_UNITS
];
641 for (subTriangle
=0; subTriangle
<=1; subTriangle
++) {
642 EdgeT
*eLeft
, *eRight
;
643 int setupLeft
, setupRight
;
646 if (subTriangle
==0) {
648 if (scan_from_left_to_right
) {
651 lines
= eRight
->lines
;
658 lines
= eLeft
->lines
;
665 if (scan_from_left_to_right
) {
668 lines
= eRight
->lines
;
675 lines
= eLeft
->lines
;
683 if (setupLeft
&& eLeft
->lines
> 0) {
684 const SWvertex
*vLower
= eLeft
->v0
;
685 const GLfixed fsx
= eLeft
->fsx
; /* no fractional part */
686 const GLfixed fsy
= eLeft
->fsy
;
687 const GLfixed fx
= FixedCeil(fsx
); /* no fractional part */
688 const GLfloat adjx
= (GLfloat
) (fx
- eLeft
->fx0
); /* SCALED! */
689 const GLfloat adjy
= eLeft
->adjy
; /* SCALED! */
694 fError
= fx
- fsx
- FIXED_ONE
;
695 fxLeftEdge
= fsx
- FIXED_EPSILON
;
696 fdxLeftEdge
= eLeft
->fdxdy
;
697 fdxOuter
= FixedFloor(fdxLeftEdge
- FIXED_EPSILON
);
698 fdError
= fdxOuter
- fdxLeftEdge
+ FIXED_ONE
;
699 idxOuter
= FixedToInt(fdxOuter
);
700 dxOuter
= (GLfloat
) idxOuter
;
702 span
.y
= FixedToInt(fsy
);
704 /* silence warnings on some compilers */
712 pRow
= (PIXEL_TYPE
*) PIXEL_ADDRESS(FixedToInt(fxLeftEdge
), span
.y
);
713 dPRowOuter
= -((int)BYTES_PER_ROW
) + idxOuter
* sizeof(PIXEL_TYPE
);
714 /* negative because Y=0 at bottom and increases upward */
718 * Now we need the set of parameter (z, color, etc.) values at
719 * the point (fx, fsy). This gives us properly-sampled parameter
720 * values that we can step from pixel to pixel. Furthermore,
721 * although we might have intermediate results that overflow
722 * the normal parameter range when we step temporarily outside
723 * the triangle, we shouldn't overflow or underflow for any
724 * pixel that's actually inside the triangle.
729 GLfloat z0
= vLower
->win
[2];
730 if (depthBits
<= 16) {
731 /* interpolate fixed-pt values */
732 GLfloat tmp
= (z0
* FIXED_SCALE
+ span
.dzdx
* adjx
+ span
.dzdy
* adjy
) + FIXED_HALF
;
733 if (tmp
< MAX_GLUINT
/ 2)
734 zLeft
= (GLfixed
) tmp
;
736 zLeft
= MAX_GLUINT
/ 2;
737 fdzOuter
= SignedFloatToFixed(span
.dzdy
+ dxOuter
* span
.dzdx
);
740 /* interpolate depth values exactly */
741 zLeft
= (GLint
) (z0
+ span
.dzdx
* FixedToFloat(adjx
) + span
.dzdy
* FixedToFloat(adjy
));
742 fdzOuter
= (GLint
) (span
.dzdy
+ dxOuter
* span
.dzdx
);
745 zRow
= (DEPTH_TYPE
*)
746 _swrast_zbuffer_address(ctx
, FixedToInt(fxLeftEdge
), span
.y
);
747 dZRowOuter
= (ctx
->DrawBuffer
->Width
+ idxOuter
) * sizeof(DEPTH_TYPE
);
752 wLeft
= vLower
->win
[3] + (span
.dwdx
* adjx
+ span
.dwdy
* adjy
) * (1.0F
/FIXED_SCALE
);
753 dwOuter
= span
.dwdy
+ dxOuter
* span
.dwdx
;
756 fogLeft
= vLower
->fog
+ (span
.dfogdx
* adjx
+ span
.dfogdy
* adjy
) * (1.0F
/FIXED_SCALE
);
757 dfogOuter
= span
.dfogdy
+ dxOuter
* span
.dfogdx
;
760 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
761 # if CHAN_TYPE == GL_FLOAT
762 rLeft
= vLower
->color
[RCOMP
] + (span
.drdx
* adjx
+ span
.drdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
763 gLeft
= vLower
->color
[GCOMP
] + (span
.dgdx
* adjx
+ span
.dgdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
764 bLeft
= vLower
->color
[BCOMP
] + (span
.dbdx
* adjx
+ span
.dbdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
765 fdrOuter
= span
.drdy
+ dxOuter
* span
.drdx
;
766 fdgOuter
= span
.dgdy
+ dxOuter
* span
.dgdx
;
767 fdbOuter
= span
.dbdy
+ dxOuter
* span
.dbdx
;
769 rLeft
= (GLint
)(ChanToFixed(vLower
->color
[RCOMP
]) + span
.drdx
* adjx
+ span
.drdy
* adjy
) + FIXED_HALF
;
770 gLeft
= (GLint
)(ChanToFixed(vLower
->color
[GCOMP
]) + span
.dgdx
* adjx
+ span
.dgdy
* adjy
) + FIXED_HALF
;
771 bLeft
= (GLint
)(ChanToFixed(vLower
->color
[BCOMP
]) + span
.dbdx
* adjx
+ span
.dbdy
* adjy
) + FIXED_HALF
;
772 fdrOuter
= SignedFloatToFixed(span
.drdy
+ dxOuter
* span
.drdx
);
773 fdgOuter
= SignedFloatToFixed(span
.dgdy
+ dxOuter
* span
.dgdx
);
774 fdbOuter
= SignedFloatToFixed(span
.dbdy
+ dxOuter
* span
.dbdx
);
777 # if CHAN_TYPE == GL_FLOAT
778 aLeft
= vLower
->color
[ACOMP
] + (span
.dadx
* adjx
+ span
.dady
* adjy
) * (1.0F
/ FIXED_SCALE
);
779 fdaOuter
= span
.dady
+ dxOuter
* span
.dadx
;
781 aLeft
= (GLint
)(ChanToFixed(vLower
->color
[ACOMP
]) + span
.dadx
* adjx
+ span
.dady
* adjy
) + FIXED_HALF
;
782 fdaOuter
= SignedFloatToFixed(span
.dady
+ dxOuter
* span
.dadx
);
787 ASSERT (ctx
->Light
.ShadeModel
== GL_FLAT
);
788 # if CHAN_TYPE == GL_FLOAT
789 rLeft
= v2
->color
[RCOMP
];
790 gLeft
= v2
->color
[GCOMP
];
791 bLeft
= v2
->color
[BCOMP
];
792 fdrOuter
= fdgOuter
= fdbOuter
= 0.0F
;
794 rLeft
= ChanToFixed(v2
->color
[RCOMP
]);
795 gLeft
= ChanToFixed(v2
->color
[GCOMP
]);
796 bLeft
= ChanToFixed(v2
->color
[BCOMP
]);
797 fdrOuter
= fdgOuter
= fdbOuter
= 0;
800 # if CHAN_TYPE == GL_FLOAT
801 aLeft
= v2
->color
[ACOMP
];
804 aLeft
= ChanToFixed(v2
->color
[ACOMP
]);
812 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
813 # if CHAN_TYPE == GL_FLOAT
814 srLeft
= vLower
->specular
[RCOMP
] + (span
.dsrdx
* adjx
+ span
.dsrdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
815 sgLeft
= vLower
->specular
[GCOMP
] + (span
.dsgdx
* adjx
+ span
.dsgdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
816 sbLeft
= vLower
->specular
[BCOMP
] + (span
.dsbdx
* adjx
+ span
.dsbdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
817 dsrOuter
= span
.dsrdy
+ dxOuter
* span
.dsrdx
;
818 dsgOuter
= span
.dsgdy
+ dxOuter
* span
.dsgdx
;
819 dsbOuter
= span
.dsbdy
+ dxOuter
* span
.dsbdx
;
821 srLeft
= (GLfixed
) (ChanToFixed(vLower
->specular
[RCOMP
]) + span
.dsrdx
* adjx
+ span
.dsrdy
* adjy
) + FIXED_HALF
;
822 sgLeft
= (GLfixed
) (ChanToFixed(vLower
->specular
[GCOMP
]) + span
.dsgdx
* adjx
+ span
.dsgdy
* adjy
) + FIXED_HALF
;
823 sbLeft
= (GLfixed
) (ChanToFixed(vLower
->specular
[BCOMP
]) + span
.dsbdx
* adjx
+ span
.dsbdy
* adjy
) + FIXED_HALF
;
824 dsrOuter
= SignedFloatToFixed(span
.dsrdy
+ dxOuter
* span
.dsrdx
);
825 dsgOuter
= SignedFloatToFixed(span
.dsgdy
+ dxOuter
* span
.dsgdx
);
826 dsbOuter
= SignedFloatToFixed(span
.dsbdy
+ dxOuter
* span
.dsbdx
);
830 #if CHAN_TYPE == GL_FLOAT
831 srLeft
= v2
->specular
[RCOMP
];
832 sgLeft
= v2
->specular
[GCOMP
];
833 sbLeft
= v2
->specular
[BCOMP
];
834 dsrOuter
= dsgOuter
= dsbOuter
= 0.0F
;
836 srLeft
= ChanToFixed(v2
->specular
[RCOMP
]);
837 sgLeft
= ChanToFixed(v2
->specular
[GCOMP
]);
838 sbLeft
= ChanToFixed(v2
->specular
[BCOMP
]);
839 dsrOuter
= dsgOuter
= dsbOuter
= 0;
845 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
846 iLeft
= (GLfixed
)(vLower
->index
* FIXED_SCALE
847 + didx
* adjx
+ didy
* adjy
) + FIXED_HALF
;
848 diOuter
= SignedFloatToFixed(didy
+ dxOuter
* didx
);
851 iLeft
= (GLfixed
) (v2
->index
* FIXED_SCALE
);
855 #ifdef INTERP_INT_TEX
858 s0
= vLower
->texcoord
[0][0] * S_SCALE
;
859 sLeft
= (GLfixed
)(s0
* FIXED_SCALE
+ span
.texStepX
[0][0] * adjx
860 + span
.texStepY
[0][0] * adjy
) + FIXED_HALF
;
861 dsOuter
= SignedFloatToFixed(span
.texStepY
[0][0] + dxOuter
* span
.texStepX
[0][0]);
863 t0
= vLower
->texcoord
[0][1] * T_SCALE
;
864 tLeft
= (GLfixed
)(t0
* FIXED_SCALE
+ span
.texStepX
[0][1] * adjx
865 + span
.texStepY
[0][1] * adjy
) + FIXED_HALF
;
866 dtOuter
= SignedFloatToFixed(span
.texStepY
[0][1] + dxOuter
* span
.texStepX
[0][1]);
871 const GLfloat invW
= vLower
->win
[3];
872 const GLfloat s0
= vLower
->texcoord
[u
][0] * invW
;
873 const GLfloat t0
= vLower
->texcoord
[u
][1] * invW
;
874 const GLfloat u0
= vLower
->texcoord
[u
][2] * invW
;
875 const GLfloat v0
= vLower
->texcoord
[u
][3] * invW
;
876 sLeft
[u
] = s0
+ (span
.texStepX
[u
][0] * adjx
+ span
.texStepY
[u
][0] * adjy
) * (1.0F
/FIXED_SCALE
);
877 tLeft
[u
] = t0
+ (span
.texStepX
[u
][1] * adjx
+ span
.texStepY
[u
][1] * adjy
) * (1.0F
/FIXED_SCALE
);
878 uLeft
[u
] = u0
+ (span
.texStepX
[u
][2] * adjx
+ span
.texStepY
[u
][2] * adjy
) * (1.0F
/FIXED_SCALE
);
879 vLeft
[u
] = v0
+ (span
.texStepX
[u
][3] * adjx
+ span
.texStepY
[u
][3] * adjy
) * (1.0F
/FIXED_SCALE
);
880 dsOuter
[u
] = span
.texStepY
[u
][0] + dxOuter
* span
.texStepX
[u
][0];
881 dtOuter
[u
] = span
.texStepY
[u
][1] + dxOuter
* span
.texStepX
[u
][1];
882 duOuter
[u
] = span
.texStepY
[u
][2] + dxOuter
* span
.texStepX
[u
][2];
883 dvOuter
[u
] = span
.texStepY
[u
][3] + dxOuter
* span
.texStepX
[u
][3];
889 if (setupRight
&& eRight
->lines
>0) {
890 fxRightEdge
= eRight
->fsx
- FIXED_EPSILON
;
891 fdxRightEdge
= eRight
->fdxdy
;
899 /* Rasterize setup */
901 dPRowInner
= dPRowOuter
+ sizeof(PIXEL_TYPE
);
905 dZRowInner
= dZRowOuter
+ sizeof(DEPTH_TYPE
);
907 fdzInner
= fdzOuter
+ span
.zStep
;
910 dwInner
= dwOuter
+ span
.dwdx
;
913 dfogInner
= dfogOuter
+ span
.dfogdx
;
916 fdrInner
= fdrOuter
+ span
.redStep
;
917 fdgInner
= fdgOuter
+ span
.greenStep
;
918 fdbInner
= fdbOuter
+ span
.blueStep
;
921 fdaInner
= fdaOuter
+ span
.alphaStep
;
924 dsrInner
= dsrOuter
+ span
.specRedStep
;
925 dsgInner
= dsgOuter
+ span
.specGreenStep
;
926 dsbInner
= dsbOuter
+ span
.specBlueStep
;
929 diInner
= diOuter
+ span
.indexStep
;
931 #ifdef INTERP_INT_TEX
932 dsInner
= dsOuter
+ span
.intTexStep
[0];
933 dtInner
= dtOuter
+ span
.intTexStep
[1];
937 dsInner
[u
] = dsOuter
[u
] + span
.texStepX
[u
][0];
938 dtInner
[u
] = dtOuter
[u
] + span
.texStepX
[u
][1];
939 duInner
[u
] = duOuter
[u
] + span
.texStepX
[u
][2];
940 dvInner
[u
] = dvOuter
[u
] + span
.texStepX
[u
][3];
945 /* initialize the span interpolants to the leftmost value */
946 /* ff = fixed-pt fragment */
947 const GLint right
= FixedToInt(fxRightEdge
);
949 span
.x
= FixedToInt(fxLeftEdge
);
954 span
.end
= right
- span
.x
;
974 span
.specRed
= srLeft
;
975 span
.specGreen
= sgLeft
;
976 span
.specBlue
= sbLeft
;
981 #ifdef INTERP_INT_TEX
982 span
.intTex
[0] = sLeft
;
983 span
.intTex
[1] = tLeft
;
988 span
.tex
[u
][0] = sLeft
[u
];
989 span
.tex
[u
][1] = tLeft
[u
];
990 span
.tex
[u
][2] = uLeft
[u
];
991 span
.tex
[u
][3] = vLeft
[u
];
996 /* Under rare circumstances, we might have to fudge the
997 * colors. XXX does this really happen anymore???
999 const GLint len
= span
.end
- 1;
1003 GLfixed ffrend
= span
.red
+ len
* span
.redStep
;
1004 GLfixed ffgend
= span
.green
+ len
* span
.greenStep
;
1005 GLfixed ffbend
= span
.blue
+ len
* span
.blueStep
;
1012 span
.green
-= ffgend
;
1017 span
.blue
-= ffbend
;
1025 GLfixed ffaend
= span
.alpha
+ len
* span
.alphaStep
;
1027 span
.alpha
-= ffaend
;
1035 GLfixed ffsrend
= span
.specRed
+ len
* span
.specRedStep
;
1036 GLfixed ffsgend
= span
.specGreen
+ len
* span
.specGreenStep
;
1037 GLfixed ffsbend
= span
.specBlue
+ len
* span
.specBlueStep
;
1039 span
.specRed
-= ffsrend
;
1040 if (span
.specRed
< 0)
1044 span
.specGreen
-= ffsgend
;
1045 if (span
.specGreen
< 0)
1049 span
.specBlue
-= ffsbend
;
1050 if (span
.specBlue
< 0)
1059 } /* span.end > 1 */
1061 /* This is where we actually generate fragments */
1063 RENDER_SPAN( span
);
1067 * Advance to the next scan line. Compute the
1068 * new edge coordinates, and adjust the
1069 * pixel-center x coordinate so that it stays
1070 * on or inside the major edge.
1075 fxLeftEdge
+= fdxLeftEdge
;
1076 fxRightEdge
+= fdxRightEdge
;
1081 fError
-= FIXED_ONE
;
1082 #ifdef PIXEL_ADDRESS
1083 pRow
= (PIXEL_TYPE
*) ((GLubyte
*) pRow
+ dPRowOuter
);
1087 zRow
= (DEPTH_TYPE
*) ((GLubyte
*) zRow
+ dZRowOuter
);
1095 fogLeft
+= dfogOuter
;
1113 #ifdef INTERP_INT_TEX
1119 sLeft
[u
] += dsOuter
[u
];
1120 tLeft
[u
] += dtOuter
[u
];
1121 uLeft
[u
] += duOuter
[u
];
1122 vLeft
[u
] += dvOuter
[u
];
1127 #ifdef PIXEL_ADDRESS
1128 pRow
= (PIXEL_TYPE
*) ((GLubyte
*) pRow
+ dPRowInner
);
1132 zRow
= (DEPTH_TYPE
*) ((GLubyte
*) zRow
+ dZRowInner
);
1140 fogLeft
+= dfogInner
;
1158 #ifdef INTERP_INT_TEX
1164 sLeft
[u
] += dsInner
[u
];
1165 tLeft
[u
] += dtInner
[u
];
1166 uLeft
[u
] += duInner
[u
];
1167 vLeft
[u
] += dvInner
[u
];
1173 } /* for subTriangle */
1187 #undef BYTES_PER_ROW
1188 #undef PIXEL_ADDRESS
1197 #undef INTERP_INT_TEX
1199 #undef INTERP_MULTITEX
1200 #undef TEX_UNIT_LOOP
1207 #undef DO_OCCLUSION_TEST