1 /* $Id: s_tritemp.h,v 1.35 2002/03/16 18:02:08 brianp Exp $ */
4 * Mesa 3-D graphics library
7 * Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
16 * The above copyright notice and this permission notice shall be included
17 * in all copies or substantial portions of the Software.
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
23 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
24 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 /* $XFree86: xc/extras/Mesa/src/swrast/s_tritemp.h,v 1.2 2002/02/27 21:07:54 tsi Exp $ */
29 * Triangle Rasterizer Template
31 * This file is #include'd to generate custom triangle rasterizers.
33 * The following macros may be defined to indicate what auxillary information
34 * must be interplated across the triangle:
35 * INTERP_Z - if defined, interpolate Z values
36 * INTERP_FOG - if defined, interpolate fog values
37 * INTERP_RGB - if defined, interpolate RGB values
38 * INTERP_ALPHA - if defined, interpolate Alpha values (req's INTERP_RGB)
39 * INTERP_SPEC - if defined, interpolate specular RGB values
40 * INTERP_INDEX - if defined, interpolate color index values
41 * INTERP_INT_TEX - if defined, interpolate integer ST texcoords
42 * (fast, simple 2-D texture mapping)
43 * INTERP_TEX - if defined, interpolate set 0 float STRQ texcoords
44 * NOTE: OpenGL STRQ = Mesa STUV (R was taken for red)
45 * INTERP_MULTITEX - if defined, interpolate N units of STRQ texcoords
46 * INTERP_FLOAT_RGBA - if defined, interpolate RGBA with floating point
47 * INTERP_FLOAT_SPEC - if defined, interpolate specular with floating point
49 * When one can directly address pixels in the color buffer the following
50 * macros can be defined and used to compute pixel addresses during
51 * rasterization (see pRow):
52 * PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint)
53 * BYTES_PER_ROW - number of bytes per row in the color buffer
54 * PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where
55 * Y==0 at bottom of screen and increases upward.
57 * Similarly, for direct depth buffer access, this type is used for depth
59 * DEPTH_TYPE - either GLushort or GLuint
61 * Optionally, one may provide one-time setup code per triangle:
62 * SETUP_CODE - code which is to be executed once per triangle
63 * CLEANUP_CODE - code to execute at end of triangle
65 * The following macro MUST be defined:
66 * RENDER_SPAN(span) - code to write a span of pixels.
68 * This code was designed for the origin to be in the lower-left corner.
70 * Inspired by triangle rasterizer code written by Allen Akin. Thanks Allen!
75 * This is a bit of a hack, but it's a centralized place to enable floating-
76 * point color interpolation when GLchan is actually floating point.
78 #if CHAN_TYPE == GL_FLOAT
80 #if defined(INTERP_RGB)
83 #define INTERP_FLOAT_RGBA
86 #if defined(INTERP_SPEC)
88 #define INTERP_FLOAT_SPEC
94 /*void triangle( GLcontext *ctx, SWvertex *v0, SWvertex *v1, SWvertex *v2 )*/
97 const SWvertex
*v0
, *v1
; /* Y(v0) < Y(v1) */
98 GLfloat dx
; /* X(v1) - X(v0) */
99 GLfloat dy
; /* Y(v1) - Y(v0) */
100 GLfixed fdxdy
; /* dx/dy in fixed-point */
101 GLfixed fsx
; /* first sample point x coord */
103 GLfloat adjy
; /* adjust from v[0]->fy to fsy, scaled */
104 GLint lines
; /* number of lines to be sampled on this edge */
105 GLfixed fx0
; /* fixed pt X of lower endpoint */
109 const GLint depthBits
= ctx
->Visual
.depthBits
;
110 const GLint fixedToDepthShift
= depthBits
<= 16 ? FIXED_SHIFT
: 0;
111 const GLfloat maxDepth
= ctx
->DepthMaxF
;
112 #define FixedToDepth(F) ((F) >> fixedToDepthShift)
114 EdgeT eMaj
, eTop
, eBot
;
116 const SWvertex
*vMin
, *vMid
, *vMax
; /* Y(vMin)<=Y(vMid)<=Y(vMax) */
117 float bf
= SWRAST_CONTEXT(ctx
)->_backface_sign
;
118 const GLint snapMask
= ~((FIXED_ONE
/ 16) - 1); /* for x/y coord snapping */
119 GLfixed vMin_fx
, vMin_fy
, vMid_fx
, vMid_fy
, vMax_fx
, vMax_fy
;
126 (void) fixedToDepthShift
;
130 printf("%s()\n", __FUNCTION__);
131 printf(" %g, %g, %g\n", v0->win[0], v0->win[1], v0->win[2]);
132 printf(" %g, %g, %g\n", v1->win[0], v1->win[1], v1->win[2]);
133 printf(" %g, %g, %g\n", v2->win[0], v2->win[1], v2->win[2]);
136 /* Compute fixed point x,y coords w/ half-pixel offsets and snapping.
137 * And find the order of the 3 vertices along the Y axis.
140 const GLfixed fy0
= FloatToFixed(v0
->win
[1] - 0.5F
) & snapMask
;
141 const GLfixed fy1
= FloatToFixed(v1
->win
[1] - 0.5F
) & snapMask
;
142 const GLfixed fy2
= FloatToFixed(v2
->win
[1] - 0.5F
) & snapMask
;
147 vMin
= v0
; vMid
= v1
; vMax
= v2
;
148 vMin_fy
= fy0
; vMid_fy
= fy1
; vMax_fy
= fy2
;
150 else if (fy2
<= fy0
) {
152 vMin
= v2
; vMid
= v0
; vMax
= v1
;
153 vMin_fy
= fy2
; vMid_fy
= fy0
; vMax_fy
= fy1
;
157 vMin
= v0
; vMid
= v2
; vMax
= v1
;
158 vMin_fy
= fy0
; vMid_fy
= fy2
; vMax_fy
= fy1
;
165 vMin
= v1
; vMid
= v0
; vMax
= v2
;
166 vMin_fy
= fy1
; vMid_fy
= fy0
; vMax_fy
= fy2
;
169 else if (fy2
<= fy1
) {
171 vMin
= v2
; vMid
= v1
; vMax
= v0
;
172 vMin_fy
= fy2
; vMid_fy
= fy1
; vMax_fy
= fy0
;
177 vMin
= v1
; vMid
= v2
; vMax
= v0
;
178 vMin_fy
= fy1
; vMid_fy
= fy2
; vMax_fy
= fy0
;
182 /* fixed point X coords */
183 vMin_fx
= FloatToFixed(vMin
->win
[0] + 0.5F
) & snapMask
;
184 vMid_fx
= FloatToFixed(vMid
->win
[0] + 0.5F
) & snapMask
;
185 vMax_fx
= FloatToFixed(vMax
->win
[0] + 0.5F
) & snapMask
;
188 /* vertex/edge relationship */
189 eMaj
.v0
= vMin
; eMaj
.v1
= vMax
; /*TODO: .v1's not needed */
190 eTop
.v0
= vMid
; eTop
.v1
= vMax
;
191 eBot
.v0
= vMin
; eBot
.v1
= vMid
;
193 /* compute deltas for each edge: vertex[upper] - vertex[lower] */
194 eMaj
.dx
= FixedToFloat(vMax_fx
- vMin_fx
);
195 eMaj
.dy
= FixedToFloat(vMax_fy
- vMin_fy
);
196 eTop
.dx
= FixedToFloat(vMax_fx
- vMid_fx
);
197 eTop
.dy
= FixedToFloat(vMax_fy
- vMid_fy
);
198 eBot
.dx
= FixedToFloat(vMid_fx
- vMin_fx
);
199 eBot
.dy
= FixedToFloat(vMid_fy
- vMin_fy
);
201 /* compute area, oneOverArea and perform backface culling */
203 const GLfloat area
= eMaj
.dx
* eBot
.dy
- eBot
.dx
* eMaj
.dy
;
205 /* Do backface culling */
209 if (area
== 0.0F
|| IS_INF_OR_NAN(area
))
212 oneOverArea
= 1.0F
/ area
;
215 #ifndef DO_OCCLUSION_TEST
216 ctx
->OcclusionResult
= GL_TRUE
;
219 /* Edge setup. For a triangle strip these could be reused... */
221 eMaj
.fsy
= FixedCeil(vMin_fy
);
222 eMaj
.lines
= FixedToInt(FixedCeil(vMax_fy
- eMaj
.fsy
));
223 if (eMaj
.lines
> 0) {
224 GLfloat dxdy
= eMaj
.dx
/ eMaj
.dy
;
225 eMaj
.fdxdy
= SignedFloatToFixed(dxdy
);
226 eMaj
.adjy
= (GLfloat
) (eMaj
.fsy
- vMin_fy
); /* SCALED! */
228 eMaj
.fsx
= eMaj
.fx0
+ (GLfixed
) (eMaj
.adjy
* dxdy
);
234 eTop
.fsy
= FixedCeil(vMid_fy
);
235 eTop
.lines
= FixedToInt(FixedCeil(vMax_fy
- eTop
.fsy
));
236 if (eTop
.lines
> 0) {
237 GLfloat dxdy
= eTop
.dx
/ eTop
.dy
;
238 eTop
.fdxdy
= SignedFloatToFixed(dxdy
);
239 eTop
.adjy
= (GLfloat
) (eTop
.fsy
- vMid_fy
); /* SCALED! */
241 eTop
.fsx
= eTop
.fx0
+ (GLfixed
) (eTop
.adjy
* dxdy
);
244 eBot
.fsy
= FixedCeil(vMin_fy
);
245 eBot
.lines
= FixedToInt(FixedCeil(vMid_fy
- eBot
.fsy
));
246 if (eBot
.lines
> 0) {
247 GLfloat dxdy
= eBot
.dx
/ eBot
.dy
;
248 eBot
.fdxdy
= SignedFloatToFixed(dxdy
);
249 eBot
.adjy
= (GLfloat
) (eBot
.fsy
- vMin_fy
); /* SCALED! */
251 eBot
.fsx
= eBot
.fx0
+ (GLfixed
) (eBot
.adjy
* dxdy
);
256 * Conceptually, we view a triangle as two subtriangles
257 * separated by a perfectly horizontal line. The edge that is
258 * intersected by this line is one with maximal absolute dy; we
259 * call it a ``major'' edge. The other two edges are the
260 * ``top'' edge (for the upper subtriangle) and the ``bottom''
261 * edge (for the lower subtriangle). If either of these two
262 * edges is horizontal or very close to horizontal, the
263 * corresponding subtriangle might cover zero sample points;
264 * we take care to handle such cases, for performance as well
267 * By stepping rasterization parameters along the major edge,
268 * we can avoid recomputing them at the discontinuity where
269 * the top and bottom edges meet. However, this forces us to
270 * be able to scan both left-to-right and right-to-left.
271 * Also, we must determine whether the major edge is at the
272 * left or right side of the triangle. We do this by
273 * computing the magnitude of the cross-product of the major
274 * and top edges. Since this magnitude depends on the sine of
275 * the angle between the two edges, its sign tells us whether
276 * we turn to the left or to the right when travelling along
277 * the major edge to the top edge, and from this we infer
278 * whether the major edge is on the left or the right.
280 * Serendipitously, this cross-product magnitude is also a
281 * value we need to compute the iteration parameter
282 * derivatives for the triangle, and it can be used to perform
283 * backface culling because its sign tells us whether the
284 * triangle is clockwise or counterclockwise. In this code we
285 * refer to it as ``area'' because it's also proportional to
286 * the pixel area of the triangle.
290 GLint scan_from_left_to_right
; /* true if scanning left-to-right */
297 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
302 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
305 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
306 GLfloat dsrdx
, dsrdy
;
307 GLfloat dsgdx
, dsgdy
;
308 GLfloat dsbdx
, dsbdy
;
313 #ifdef INTERP_INT_TEX
323 #ifdef INTERP_MULTITEX
324 GLfloat dsdx
[MAX_TEXTURE_UNITS
], dsdy
[MAX_TEXTURE_UNITS
];
325 GLfloat dtdx
[MAX_TEXTURE_UNITS
], dtdy
[MAX_TEXTURE_UNITS
];
326 GLfloat dudx
[MAX_TEXTURE_UNITS
], dudy
[MAX_TEXTURE_UNITS
];
327 GLfloat dvdx
[MAX_TEXTURE_UNITS
], dvdy
[MAX_TEXTURE_UNITS
];
331 * Execute user-supplied setup code
337 scan_from_left_to_right
= (oneOverArea
< 0.0F
);
340 /* compute d?/dx and d?/dy derivatives */
342 span
.interpMask
|= SPAN_Z
;
344 GLfloat eMaj_dz
, eBot_dz
;
345 eMaj_dz
= vMax
->win
[2] - vMin
->win
[2];
346 eBot_dz
= vMid
->win
[2] - vMin
->win
[2];
347 dzdx
= oneOverArea
* (eMaj_dz
* eBot
.dy
- eMaj
.dy
* eBot_dz
);
348 if (dzdx
> maxDepth
|| dzdx
< -maxDepth
) {
349 /* probably a sliver triangle */
354 dzdy
= oneOverArea
* (eMaj
.dx
* eBot_dz
- eMaj_dz
* eBot
.dx
);
357 span
.zStep
= SignedFloatToFixed(dzdx
);
359 span
.zStep
= (GLint
) dzdx
;
363 span
.interpMask
|= SPAN_FOG
;
365 const GLfloat eMaj_dfog
= vMax
->fog
- vMin
->fog
;
366 const GLfloat eBot_dfog
= vMid
->fog
- vMin
->fog
;
367 span
.fogStep
= oneOverArea
* (eMaj_dfog
* eBot
.dy
- eMaj
.dy
* eBot_dfog
);
368 dfogdy
= oneOverArea
* (eMaj
.dx
* eBot_dfog
- eMaj_dfog
* eBot
.dx
);
372 span
.interpMask
|= SPAN_RGBA
;
373 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
374 GLfloat eMaj_dr
, eBot_dr
;
375 GLfloat eMaj_dg
, eBot_dg
;
376 GLfloat eMaj_db
, eBot_db
;
378 GLfloat eMaj_da
, eBot_da
;
380 eMaj_dr
= (GLfloat
) ((GLint
) vMax
->color
[RCOMP
] -
381 (GLint
) vMin
->color
[RCOMP
]);
382 eBot_dr
= (GLfloat
) ((GLint
) vMid
->color
[RCOMP
] -
383 (GLint
) vMin
->color
[RCOMP
]);
384 drdx
= oneOverArea
* (eMaj_dr
* eBot
.dy
- eMaj
.dy
* eBot_dr
);
385 span
.redStep
= SignedFloatToFixed(drdx
);
386 drdy
= oneOverArea
* (eMaj
.dx
* eBot_dr
- eMaj_dr
* eBot
.dx
);
387 eMaj_dg
= (GLfloat
) ((GLint
) vMax
->color
[GCOMP
] -
388 (GLint
) vMin
->color
[GCOMP
]);
389 eBot_dg
= (GLfloat
) ((GLint
) vMid
->color
[GCOMP
] -
390 (GLint
) vMin
->color
[GCOMP
]);
391 dgdx
= oneOverArea
* (eMaj_dg
* eBot
.dy
- eMaj
.dy
* eBot_dg
);
392 span
.greenStep
= SignedFloatToFixed(dgdx
);
393 dgdy
= oneOverArea
* (eMaj
.dx
* eBot_dg
- eMaj_dg
* eBot
.dx
);
394 eMaj_db
= (GLfloat
) ((GLint
) vMax
->color
[BCOMP
] -
395 (GLint
) vMin
->color
[BCOMP
]);
396 eBot_db
= (GLfloat
) ((GLint
) vMid
->color
[BCOMP
] -
397 (GLint
) vMin
->color
[BCOMP
]);
398 dbdx
= oneOverArea
* (eMaj_db
* eBot
.dy
- eMaj
.dy
* eBot_db
);
399 span
.blueStep
= SignedFloatToFixed(dbdx
);
400 dbdy
= oneOverArea
* (eMaj
.dx
* eBot_db
- eMaj_db
* eBot
.dx
);
402 eMaj_da
= (GLfloat
) ((GLint
) vMax
->color
[ACOMP
] -
403 (GLint
) vMin
->color
[ACOMP
]);
404 eBot_da
= (GLfloat
) ((GLint
) vMid
->color
[ACOMP
] -
405 (GLint
) vMin
->color
[ACOMP
]);
406 dadx
= oneOverArea
* (eMaj_da
* eBot
.dy
- eMaj
.dy
* eBot_da
);
407 span
.alphaStep
= SignedFloatToFixed(dadx
);
408 dady
= oneOverArea
* (eMaj
.dx
* eBot_da
- eMaj_da
* eBot
.dx
);
412 ASSERT (ctx
->Light
.ShadeModel
== GL_FLAT
);
413 span
.interpMask
|= SPAN_FLAT
;
426 #ifdef INTERP_FLOAT_RGBA
427 span
.interpMask
|= SPAN_RGBA
;
428 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
429 GLfloat eMaj_dr
, eBot_dr
;
430 GLfloat eMaj_dg
, eBot_dg
;
431 GLfloat eMaj_db
, eBot_db
;
432 GLfloat eMaj_da
, eBot_da
;
433 eMaj_dr
= vMax
->color
[RCOMP
] - vMin
->color
[RCOMP
];
434 eBot_dr
= vMid
->color
[RCOMP
] - vMin
->color
[RCOMP
];
435 drdx
= oneOverArea
* (eMaj_dr
* eBot
.dy
- eMaj
.dy
* eBot_dr
);
437 drdy
= oneOverArea
* (eMaj
.dx
* eBot_dr
- eMaj_dr
* eBot
.dx
);
438 eMaj_dg
= vMax
->color
[GCOMP
] - vMin
->color
[GCOMP
];
439 eBot_dg
= vMid
->color
[GCOMP
] - vMin
->color
[GCOMP
];
440 dgdx
= oneOverArea
* (eMaj_dg
* eBot
.dy
- eMaj
.dy
* eBot_dg
);
441 span
.greenStep
= dgdx
;
442 dgdy
= oneOverArea
* (eMaj
.dx
* eBot_dg
- eMaj_dg
* eBot
.dx
);
443 eMaj_db
= vMax
->color
[BCOMP
] - vMin
->color
[BCOMP
];
444 eBot_db
= vMid
->color
[BCOMP
] - vMin
->color
[BCOMP
];
445 dbdx
= oneOverArea
* (eMaj_db
* eBot
.dy
- eMaj
.dy
* eBot_db
);
446 span
.blueStep
= dbdx
;
447 dbdy
= oneOverArea
* (eMaj
.dx
* eBot_db
- eMaj_db
* eBot
.dx
);
448 eMaj_da
= vMax
->color
[ACOMP
] - vMin
->color
[ACOMP
];
449 eBot_da
= vMid
->color
[ACOMP
] - vMin
->color
[ACOMP
];
450 dadx
= oneOverArea
* (eMaj_da
* eBot
.dy
- eMaj
.dy
* eBot_da
);
451 span
.alphaStep
= dadx
;
452 dady
= oneOverArea
* (eMaj
.dx
* eBot_da
- eMaj_da
* eBot
.dx
);
455 drdx
= drdy
= span
.redStep
= 0.0F
;
456 dgdx
= dgdy
= span
.greenStep
= 0.0F
;
457 dbdx
= dbdy
= span
.blueStep
= 0.0F
;
458 dadx
= dady
= span
.alphaStep
= 0.0F
;
462 span
.interpMask
|= SPAN_SPEC
;
463 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
464 GLfloat eMaj_dsr
, eBot_dsr
;
465 GLfloat eMaj_dsg
, eBot_dsg
;
466 GLfloat eMaj_dsb
, eBot_dsb
;
467 eMaj_dsr
= (GLfloat
) ((GLint
) vMax
->specular
[RCOMP
] -
468 (GLint
) vMin
->specular
[RCOMP
]);
469 eBot_dsr
= (GLfloat
) ((GLint
) vMid
->specular
[RCOMP
] -
470 (GLint
) vMin
->specular
[RCOMP
]);
471 dsrdx
= oneOverArea
* (eMaj_dsr
* eBot
.dy
- eMaj
.dy
* eBot_dsr
);
472 span
.specRedStep
= SignedFloatToFixed(dsrdx
);
473 dsrdy
= oneOverArea
* (eMaj
.dx
* eBot_dsr
- eMaj_dsr
* eBot
.dx
);
474 eMaj_dsg
= (GLfloat
) ((GLint
) vMax
->specular
[GCOMP
] -
475 (GLint
) vMin
->specular
[GCOMP
]);
476 eBot_dsg
= (GLfloat
) ((GLint
) vMid
->specular
[GCOMP
] -
477 (GLint
) vMin
->specular
[GCOMP
]);
478 dsgdx
= oneOverArea
* (eMaj_dsg
* eBot
.dy
- eMaj
.dy
* eBot_dsg
);
479 span
.specGreenStep
= SignedFloatToFixed(dsgdx
);
480 dsgdy
= oneOverArea
* (eMaj
.dx
* eBot_dsg
- eMaj_dsg
* eBot
.dx
);
481 eMaj_dsb
= (GLfloat
) ((GLint
) vMax
->specular
[BCOMP
] -
482 (GLint
) vMin
->specular
[BCOMP
]);
483 eBot_dsb
= (GLfloat
) ((GLint
) vMid
->specular
[BCOMP
] -
484 (GLint
) vMin
->specular
[BCOMP
]);
485 dsbdx
= oneOverArea
* (eMaj_dsb
* eBot
.dy
- eMaj
.dy
* eBot_dsb
);
486 span
.specBlueStep
= SignedFloatToFixed(dsbdx
);
487 dsbdy
= oneOverArea
* (eMaj
.dx
* eBot_dsb
- eMaj_dsb
* eBot
.dx
);
490 dsrdx
= dsrdy
= 0.0F
;
491 dsgdx
= dsgdy
= 0.0F
;
492 dsbdx
= dsbdy
= 0.0F
;
493 span
.specRedStep
= 0;
494 span
.specGreenStep
= 0;
495 span
.specBlueStep
= 0;
498 #ifdef INTERP_FLOAT_SPEC
499 span
.interpMask
|= SPAN_SPEC
;
500 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
501 GLfloat eMaj_dsr
, eBot_dsr
;
502 GLfloat eMaj_dsg
, eBot_dsg
;
503 GLfloat eMaj_dsb
, eBot_dsb
;
504 eMaj_dsr
= vMax
->specular
[RCOMP
] - vMin
->specular
[RCOMP
];
505 eBot_dsr
= vMid
->specular
[RCOMP
] - vMin
->specular
[RCOMP
];
506 dsrdx
= oneOverArea
* (eMaj_dsr
* eBot
.dy
- eMaj
.dy
* eBot_dsr
);
507 span
.specRedStep
= dsrdx
;
508 dsrdy
= oneOverArea
* (eMaj
.dx
* eBot_dsr
- eMaj_dsr
* eBot
.dx
);
509 eMaj_dsg
= vMax
->specular
[GCOMP
] - vMin
->specular
[GCOMP
];
510 eBot_dsg
= vMid
->specular
[GCOMP
] - vMin
->specular
[GCOMP
];
511 dsgdx
= oneOverArea
* (eMaj_dsg
* eBot
.dy
- eMaj
.dy
* eBot_dsg
);
512 span
.specGreenStep
= dsgdx
;
513 dsgdy
= oneOverArea
* (eMaj
.dx
* eBot_dsg
- eMaj_dsg
* eBot
.dx
);
514 eMaj_dsb
= vMax
->specular
[BCOMP
] - vMin
->specular
[BCOMP
];
515 eBot_dsb
= vMid
->specular
[BCOMP
] - vMin
->specular
[BCOMP
];
516 dsbdx
= oneOverArea
* (eMaj_dsb
* eBot
.dy
- eMaj
.dy
* eBot_dsb
);
517 span
.specBlueStep
= dsbdx
;
518 dsbdy
= oneOverArea
* (eMaj
.dx
* eBot_dsb
- eMaj_dsb
* eBot
.dx
);
521 dsrdx
= dsrdy
= span
.specRedStep
= 0;
522 dsgdx
= dsgdy
= span
.specGreenStep
= 0;
523 dsbdx
= dsbdy
= span
.specBlueStep
= 0;
527 span
.interpMask
|= SPAN_INDEX
;
528 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
529 GLfloat eMaj_di
, eBot_di
;
530 eMaj_di
= (GLfloat
) ((GLint
) vMax
->index
- (GLint
) vMin
->index
);
531 eBot_di
= (GLfloat
) ((GLint
) vMid
->index
- (GLint
) vMin
->index
);
532 didx
= oneOverArea
* (eMaj_di
* eBot
.dy
- eMaj
.dy
* eBot_di
);
533 span
.indexStep
= SignedFloatToFixed(didx
);
534 didy
= oneOverArea
* (eMaj
.dx
* eBot_di
- eMaj_di
* eBot
.dx
);
537 span
.interpMask
|= SPAN_FLAT
;
542 #ifdef INTERP_INT_TEX
543 span
.interpMask
|= SPAN_INT_TEXTURE
;
545 GLfloat eMaj_ds
, eBot_ds
;
546 eMaj_ds
= (vMax
->texcoord
[0][0] - vMin
->texcoord
[0][0]) * S_SCALE
;
547 eBot_ds
= (vMid
->texcoord
[0][0] - vMin
->texcoord
[0][0]) * S_SCALE
;
548 dsdx
= oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
549 span
.intTexStep
[0] = SignedFloatToFixed(dsdx
);
550 dsdy
= oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
553 GLfloat eMaj_dt
, eBot_dt
;
554 eMaj_dt
= (vMax
->texcoord
[0][1] - vMin
->texcoord
[0][1]) * T_SCALE
;
555 eBot_dt
= (vMid
->texcoord
[0][1] - vMin
->texcoord
[0][1]) * T_SCALE
;
556 dtdx
= oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
557 span
.intTexStep
[1] = SignedFloatToFixed(dtdx
);
558 dtdy
= oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
563 span
.interpMask
|= SPAN_TEXTURE
;
565 GLfloat wMax
= vMax
->win
[3];
566 GLfloat wMin
= vMin
->win
[3];
567 GLfloat wMid
= vMid
->win
[3];
568 GLfloat eMaj_ds
, eBot_ds
;
569 GLfloat eMaj_dt
, eBot_dt
;
570 GLfloat eMaj_du
, eBot_du
;
571 GLfloat eMaj_dv
, eBot_dv
;
573 eMaj_ds
= vMax
->texcoord
[0][0] * wMax
- vMin
->texcoord
[0][0] * wMin
;
574 eBot_ds
= vMid
->texcoord
[0][0] * wMid
- vMin
->texcoord
[0][0] * wMin
;
575 dsdx
= oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
576 dsdy
= oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
577 span
.texStepX
[0][0] = dsdx
;
578 span
.texStepY
[0][0] = dsdy
;
580 eMaj_dt
= vMax
->texcoord
[0][1] * wMax
- vMin
->texcoord
[0][1] * wMin
;
581 eBot_dt
= vMid
->texcoord
[0][1] * wMid
- vMin
->texcoord
[0][1] * wMin
;
582 dtdx
= oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
583 dtdy
= oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
584 span
.texStepX
[0][1] = dtdx
;
585 span
.texStepY
[0][1] = dtdy
;
587 eMaj_du
= vMax
->texcoord
[0][2] * wMax
- vMin
->texcoord
[0][2] * wMin
;
588 eBot_du
= vMid
->texcoord
[0][2] * wMid
- vMin
->texcoord
[0][2] * wMin
;
589 dudx
= oneOverArea
* (eMaj_du
* eBot
.dy
- eMaj
.dy
* eBot_du
);
590 dudy
= oneOverArea
* (eMaj
.dx
* eBot_du
- eMaj_du
* eBot
.dx
);
591 span
.texStepX
[0][2] = dudx
;
592 span
.texStepY
[0][2] = dudy
;
594 eMaj_dv
= vMax
->texcoord
[0][3] * wMax
- vMin
->texcoord
[0][3] * wMin
;
595 eBot_dv
= vMid
->texcoord
[0][3] * wMid
- vMin
->texcoord
[0][3] * wMin
;
596 dvdx
= oneOverArea
* (eMaj_dv
* eBot
.dy
- eMaj
.dy
* eBot_dv
);
597 dvdy
= oneOverArea
* (eMaj
.dx
* eBot_dv
- eMaj_dv
* eBot
.dx
);
598 span
.texStepX
[0][3] = dvdx
;
599 span
.texStepY
[0][3] = dvdy
;
602 #ifdef INTERP_MULTITEX
603 span
.interpMask
|= SPAN_TEXTURE
;
605 GLfloat wMax
= vMax
->win
[3];
606 GLfloat wMin
= vMin
->win
[3];
607 GLfloat wMid
= vMid
->win
[3];
609 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
610 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
611 GLfloat eMaj_ds
, eBot_ds
;
612 GLfloat eMaj_dt
, eBot_dt
;
613 GLfloat eMaj_du
, eBot_du
;
614 GLfloat eMaj_dv
, eBot_dv
;
615 eMaj_ds
= vMax
->texcoord
[u
][0] * wMax
616 - vMin
->texcoord
[u
][0] * wMin
;
617 eBot_ds
= vMid
->texcoord
[u
][0] * wMid
618 - vMin
->texcoord
[u
][0] * wMin
;
619 dsdx
[u
] = oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
620 dsdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
621 span
.texStepX
[u
][0] = dsdx
[u
];
622 span
.texStepY
[u
][0] = dsdy
[u
];
624 eMaj_dt
= vMax
->texcoord
[u
][1] * wMax
625 - vMin
->texcoord
[u
][1] * wMin
;
626 eBot_dt
= vMid
->texcoord
[u
][1] * wMid
627 - vMin
->texcoord
[u
][1] * wMin
;
628 dtdx
[u
] = oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
629 dtdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
630 span
.texStepX
[u
][1] = dtdx
[u
];
631 span
.texStepY
[u
][1] = dtdy
[u
];
633 eMaj_du
= vMax
->texcoord
[u
][2] * wMax
634 - vMin
->texcoord
[u
][2] * wMin
;
635 eBot_du
= vMid
->texcoord
[u
][2] * wMid
636 - vMin
->texcoord
[u
][2] * wMin
;
637 dudx
[u
] = oneOverArea
* (eMaj_du
* eBot
.dy
- eMaj
.dy
* eBot_du
);
638 dudy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_du
- eMaj_du
* eBot
.dx
);
639 span
.texStepX
[u
][2] = dudx
[u
];
640 span
.texStepY
[u
][2] = dudy
[u
];
642 eMaj_dv
= vMax
->texcoord
[u
][3] * wMax
643 - vMin
->texcoord
[u
][3] * wMin
;
644 eBot_dv
= vMid
->texcoord
[u
][3] * wMid
645 - vMin
->texcoord
[u
][3] * wMin
;
646 dvdx
[u
] = oneOverArea
* (eMaj_dv
* eBot
.dy
- eMaj
.dy
* eBot_dv
);
647 dvdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_dv
- eMaj_dv
* eBot
.dx
);
648 span
.texStepX
[u
][3] = dvdx
[u
];
649 span
.texStepY
[u
][3] = dvdy
[u
];
656 * We always sample at pixel centers. However, we avoid
657 * explicit half-pixel offsets in this code by incorporating
658 * the proper offset in each of x and y during the
659 * transformation to window coordinates.
661 * We also apply the usual rasterization rules to prevent
662 * cracks and overlaps. A pixel is considered inside a
663 * subtriangle if it meets all of four conditions: it is on or
664 * to the right of the left edge, strictly to the left of the
665 * right edge, on or below the top edge, and strictly above
666 * the bottom edge. (Some edges may be degenerate.)
668 * The following discussion assumes left-to-right scanning
669 * (that is, the major edge is on the left); the right-to-left
670 * case is a straightforward variation.
672 * We start by finding the half-integral y coordinate that is
673 * at or below the top of the triangle. This gives us the
674 * first scan line that could possibly contain pixels that are
675 * inside the triangle.
677 * Next we creep down the major edge until we reach that y,
678 * and compute the corresponding x coordinate on the edge.
679 * Then we find the half-integral x that lies on or just
680 * inside the edge. This is the first pixel that might lie in
681 * the interior of the triangle. (We won't know for sure
682 * until we check the other edges.)
684 * As we rasterize the triangle, we'll step down the major
685 * edge. For each step in y, we'll move an integer number
686 * of steps in x. There are two possible x step sizes, which
687 * we'll call the ``inner'' step (guaranteed to land on the
688 * edge or inside it) and the ``outer'' step (guaranteed to
689 * land on the edge or outside it). The inner and outer steps
690 * differ by one. During rasterization we maintain an error
691 * term that indicates our distance from the true edge, and
692 * select either the inner step or the outer step, whichever
693 * gets us to the first pixel that falls inside the triangle.
695 * All parameters (z, red, etc.) as well as the buffer
696 * addresses for color and z have inner and outer step values,
697 * so that we can increment them appropriately. This method
698 * eliminates the need to adjust parameters by creeping a
699 * sub-pixel amount into the triangle at each scanline.
705 GLfixed fxLeftEdge
= 0, fxRightEdge
= 0;
706 GLfixed fdxLeftEdge
= 0, fdxRightEdge
= 0;
710 GLfixed fError
= 0, fdError
= 0;
714 PIXEL_TYPE
*pRow
= NULL
;
715 int dPRowOuter
= 0, dPRowInner
; /* offset in bytes */
719 DEPTH_TYPE
*zRow
= NULL
;
720 int dZRowOuter
= 0, dZRowInner
; /* offset in bytes */
722 GLfixed fz
= 0, fdzOuter
= 0, fdzInner
;
725 GLfloat fogLeft
= 0, dfogOuter
= 0, dfogInner
;
728 GLfixed fr
= 0, fdrOuter
= 0, fdrInner
;
729 GLfixed fg
= 0, fdgOuter
= 0, fdgInner
;
730 GLfixed fb
= 0, fdbOuter
= 0, fdbInner
;
733 GLfixed fa
= 0, fdaOuter
= 0, fdaInner
;
735 #ifdef INTERP_FLOAT_RGBA
736 GLfloat fr
, fdrOuter
, fdrInner
;
737 GLfloat fg
, fdgOuter
, fdgInner
;
738 GLfloat fb
, fdbOuter
, fdbInner
;
739 GLfloat fa
, fdaOuter
, fdaInner
;
742 GLfixed fsr
=0, fdsrOuter
=0, fdsrInner
;
743 GLfixed fsg
=0, fdsgOuter
=0, fdsgInner
;
744 GLfixed fsb
=0, fdsbOuter
=0, fdsbInner
;
746 #ifdef INTERP_FLOAT_SPEC
747 GLfloat fsr
=0, fdsrOuter
=0, fdsrInner
;
748 GLfloat fsg
=0, fdsgOuter
=0, fdsgInner
;
749 GLfloat fsb
=0, fdsbOuter
=0, fdsbInner
;
752 GLfixed fi
=0, fdiOuter
=0, fdiInner
;
754 #ifdef INTERP_INT_TEX
755 GLfixed fs
=0, fdsOuter
=0, fdsInner
;
756 GLfixed ft
=0, fdtOuter
=0, fdtInner
;
759 GLfloat sLeft
=0, dsOuter
=0, dsInner
;
760 GLfloat tLeft
=0, dtOuter
=0, dtInner
;
761 GLfloat uLeft
=0, duOuter
=0, duInner
;
762 GLfloat vLeft
=0, dvOuter
=0, dvInner
;
764 #ifdef INTERP_MULTITEX
765 GLfloat sLeft
[MAX_TEXTURE_UNITS
];
766 GLfloat tLeft
[MAX_TEXTURE_UNITS
];
767 GLfloat uLeft
[MAX_TEXTURE_UNITS
];
768 GLfloat vLeft
[MAX_TEXTURE_UNITS
];
769 GLfloat dsOuter
[MAX_TEXTURE_UNITS
], dsInner
[MAX_TEXTURE_UNITS
];
770 GLfloat dtOuter
[MAX_TEXTURE_UNITS
], dtInner
[MAX_TEXTURE_UNITS
];
771 GLfloat duOuter
[MAX_TEXTURE_UNITS
], duInner
[MAX_TEXTURE_UNITS
];
772 GLfloat dvOuter
[MAX_TEXTURE_UNITS
], dvInner
[MAX_TEXTURE_UNITS
];
775 for (subTriangle
=0; subTriangle
<=1; subTriangle
++) {
776 EdgeT
*eLeft
, *eRight
;
777 int setupLeft
, setupRight
;
780 if (subTriangle
==0) {
782 if (scan_from_left_to_right
) {
785 lines
= eRight
->lines
;
792 lines
= eLeft
->lines
;
799 if (scan_from_left_to_right
) {
802 lines
= eRight
->lines
;
809 lines
= eLeft
->lines
;
817 if (setupLeft
&& eLeft
->lines
> 0) {
818 const SWvertex
*vLower
;
819 GLfixed fsx
= eLeft
->fsx
;
821 fError
= fx
- fsx
- FIXED_ONE
;
822 fxLeftEdge
= fsx
- FIXED_EPSILON
;
823 fdxLeftEdge
= eLeft
->fdxdy
;
824 fdxOuter
= FixedFloor(fdxLeftEdge
- FIXED_EPSILON
);
825 fdError
= fdxOuter
- fdxLeftEdge
+ FIXED_ONE
;
826 idxOuter
= FixedToInt(fdxOuter
);
827 dxOuter
= (float) idxOuter
;
831 span
.y
= FixedToInt(fy
);
833 adjx
= (float)(fx
- eLeft
->fx0
); /* SCALED! */
834 adjy
= eLeft
->adjy
; /* SCALED! */
835 (void) adjx
; /* silence compiler warnings */
836 (void) adjy
; /* silence compiler warnings */
839 (void) vLower
; /* silence compiler warnings */
843 pRow
= (PIXEL_TYPE
*) PIXEL_ADDRESS(FixedToInt(fxLeftEdge
), span
.y
);
844 dPRowOuter
= -((int)BYTES_PER_ROW
) + idxOuter
* sizeof(PIXEL_TYPE
);
845 /* negative because Y=0 at bottom and increases upward */
849 * Now we need the set of parameter (z, color, etc.) values at
850 * the point (fx, fy). This gives us properly-sampled parameter
851 * values that we can step from pixel to pixel. Furthermore,
852 * although we might have intermediate results that overflow
853 * the normal parameter range when we step temporarily outside
854 * the triangle, we shouldn't overflow or underflow for any
855 * pixel that's actually inside the triangle.
860 GLfloat z0
= vLower
->win
[2];
861 if (depthBits
<= 16) {
862 /* interpolate fixed-pt values */
863 GLfloat tmp
= (z0
* FIXED_SCALE
+
864 dzdx
* adjx
+ dzdy
* adjy
) + FIXED_HALF
;
865 if (tmp
< MAX_GLUINT
/ 2)
869 fdzOuter
= SignedFloatToFixed(dzdy
+ dxOuter
* dzdx
);
872 /* interpolate depth values exactly */
873 fz
= (GLint
) (z0
+ dzdx
* FixedToFloat(adjx
)
874 + dzdy
* FixedToFloat(adjy
));
875 fdzOuter
= (GLint
) (dzdy
+ dxOuter
* dzdx
);
878 zRow
= (DEPTH_TYPE
*)
879 _mesa_zbuffer_address(ctx
, FixedToInt(fxLeftEdge
), span
.y
);
880 dZRowOuter
= (ctx
->DrawBuffer
->Width
+ idxOuter
) * sizeof(DEPTH_TYPE
);
885 fogLeft
= vLower
->fog
+ (span
.fogStep
* adjx
+ dfogdy
* adjy
)
886 * (1.0F
/FIXED_SCALE
);
887 dfogOuter
= dfogdy
+ dxOuter
* span
.fogStep
;
890 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
891 fr
= (GLfixed
) (ChanToFixed(vLower
->color
[RCOMP
])
892 + drdx
* adjx
+ drdy
* adjy
) + FIXED_HALF
;
893 fdrOuter
= SignedFloatToFixed(drdy
+ dxOuter
* drdx
);
894 fg
= (GLfixed
) (ChanToFixed(vLower
->color
[GCOMP
])
895 + dgdx
* adjx
+ dgdy
* adjy
) + FIXED_HALF
;
896 fdgOuter
= SignedFloatToFixed(dgdy
+ dxOuter
* dgdx
);
897 fb
= (GLfixed
) (ChanToFixed(vLower
->color
[BCOMP
])
898 + dbdx
* adjx
+ dbdy
* adjy
) + FIXED_HALF
;
899 fdbOuter
= SignedFloatToFixed(dbdy
+ dxOuter
* dbdx
);
901 fa
= (GLfixed
) (ChanToFixed(vLower
->color
[ACOMP
])
902 + dadx
* adjx
+ dady
* adjy
) + FIXED_HALF
;
903 fdaOuter
= SignedFloatToFixed(dady
+ dxOuter
* dadx
);
907 ASSERT (ctx
->Light
.ShadeModel
== GL_FLAT
);
908 fr
= ChanToFixed(v2
->color
[RCOMP
]);
909 fg
= ChanToFixed(v2
->color
[GCOMP
]);
910 fb
= ChanToFixed(v2
->color
[BCOMP
]);
911 fdrOuter
= fdgOuter
= fdbOuter
= 0;
913 fa
= ChanToFixed(v2
->color
[ACOMP
]);
918 #ifdef INTERP_FLOAT_RGBA
919 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
920 fr
= vLower
->color
[RCOMP
]
921 + (drdx
* adjx
+ drdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
922 fdrOuter
= drdy
+ dxOuter
* drdx
;
923 fg
= vLower
->color
[GCOMP
]
924 + (dgdx
* adjx
+ dgdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
925 fdgOuter
= dgdy
+ dxOuter
* dgdx
;
926 fb
= vLower
->color
[BCOMP
]
927 + (dbdx
* adjx
+ dbdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
928 fdbOuter
= dbdy
+ dxOuter
* dbdx
;
929 fa
= vLower
->color
[ACOMP
]
930 + (dadx
* adjx
+ dady
* adjy
) * (1.0F
/ FIXED_SCALE
);
931 fdaOuter
= dady
+ dxOuter
* dadx
;
934 fr
= v2
->color
[RCOMP
];
935 fg
= v2
->color
[GCOMP
];
936 fb
= v2
->color
[BCOMP
];
937 fa
= v2
->color
[ACOMP
];
938 fdrOuter
= fdgOuter
= fdbOuter
= fdaOuter
= 0.0F
;
942 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
943 fsr
= (GLfixed
) (ChanToFixed(vLower
->specular
[RCOMP
])
944 + dsrdx
* adjx
+ dsrdy
* adjy
) + FIXED_HALF
;
945 fdsrOuter
= SignedFloatToFixed(dsrdy
+ dxOuter
* dsrdx
);
946 fsg
= (GLfixed
) (ChanToFixed(vLower
->specular
[GCOMP
])
947 + dsgdx
* adjx
+ dsgdy
* adjy
) + FIXED_HALF
;
948 fdsgOuter
= SignedFloatToFixed(dsgdy
+ dxOuter
* dsgdx
);
949 fsb
= (GLfixed
) (ChanToFixed(vLower
->specular
[BCOMP
])
950 + dsbdx
* adjx
+ dsbdy
* adjy
) + FIXED_HALF
;
951 fdsbOuter
= SignedFloatToFixed(dsbdy
+ dxOuter
* dsbdx
);
954 fsr
= ChanToFixed(v2
->specular
[RCOMP
]);
955 fsg
= ChanToFixed(v2
->specular
[GCOMP
]);
956 fsb
= ChanToFixed(v2
->specular
[BCOMP
]);
957 fdsrOuter
= fdsgOuter
= fdsbOuter
= 0;
960 #ifdef INTERP_FLOAT_SPEC
961 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
962 fsr
= vLower
->specular
[RCOMP
]
963 + (dsrdx
* adjx
+ dsrdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
964 fdsrOuter
= dsrdy
+ dxOuter
* dsrdx
;
965 fsg
= vLower
->specular
[GCOMP
]
966 + (dsgdx
* adjx
+ dsgdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
967 fdsgOuter
= dsgdy
+ dxOuter
* dsgdx
;
968 fsb
= vLower
->specular
[BCOMP
]
969 + (dsbdx
* adjx
+ dsbdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
970 fdsbOuter
= dsbdy
+ dxOuter
* dsbdx
;
973 fsr
= v2
->specular
[RCOMP
];
974 fsg
= v2
->specular
[GCOMP
];
975 fsb
= v2
->specular
[BCOMP
];
976 fdsrOuter
= fdsgOuter
= fdsbOuter
= 0.0F
;
980 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
981 fi
= (GLfixed
)(vLower
->index
* FIXED_SCALE
982 + didx
* adjx
+ didy
* adjy
) + FIXED_HALF
;
983 fdiOuter
= SignedFloatToFixed(didy
+ dxOuter
* didx
);
986 fi
= (GLfixed
) (v2
->index
* FIXED_SCALE
);
990 #ifdef INTERP_INT_TEX
993 s0
= vLower
->texcoord
[0][0] * S_SCALE
;
994 fs
= (GLfixed
)(s0
* FIXED_SCALE
+ dsdx
* adjx
995 + dsdy
* adjy
) + FIXED_HALF
;
996 fdsOuter
= SignedFloatToFixed(dsdy
+ dxOuter
* dsdx
);
998 t0
= vLower
->texcoord
[0][1] * T_SCALE
;
999 ft
= (GLfixed
)(t0
* FIXED_SCALE
+ dtdx
* adjx
1000 + dtdy
* adjy
) + FIXED_HALF
;
1001 fdtOuter
= SignedFloatToFixed(dtdy
+ dxOuter
* dtdx
);
1006 GLfloat invW
= vLower
->win
[3];
1007 GLfloat s0
, t0
, u0
, v0
;
1008 s0
= vLower
->texcoord
[0][0] * invW
;
1009 sLeft
= s0
+ (span
.texStepX
[0][0] * adjx
+ dsdy
* adjy
)
1010 * (1.0F
/FIXED_SCALE
);
1011 dsOuter
= dsdy
+ dxOuter
* span
.texStepX
[0][0];
1012 t0
= vLower
->texcoord
[0][1] * invW
;
1013 tLeft
= t0
+ (span
.texStepX
[0][1] * adjx
+ dtdy
* adjy
)
1014 * (1.0F
/FIXED_SCALE
);
1015 dtOuter
= dtdy
+ dxOuter
* span
.texStepX
[0][1];
1016 u0
= vLower
->texcoord
[0][2] * invW
;
1017 uLeft
= u0
+ (span
.texStepX
[0][2] * adjx
+ dudy
* adjy
)
1018 * (1.0F
/FIXED_SCALE
);
1019 duOuter
= dudy
+ dxOuter
* span
.texStepX
[0][2];
1020 v0
= vLower
->texcoord
[0][3] * invW
;
1021 vLeft
= v0
+ (span
.texStepX
[0][3] * adjx
+ dvdy
* adjy
)
1022 * (1.0F
/FIXED_SCALE
);
1023 dvOuter
= dvdy
+ dxOuter
* span
.texStepX
[0][3];
1026 #ifdef INTERP_MULTITEX
1029 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1030 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1031 GLfloat invW
= vLower
->win
[3];
1032 GLfloat s0
, t0
, u0
, v0
;
1033 s0
= vLower
->texcoord
[u
][0] * invW
;
1034 sLeft
[u
] = s0
+ (span
.texStepX
[u
][0] * adjx
+ dsdy
[u
]
1035 * adjy
) * (1.0F
/FIXED_SCALE
);
1036 dsOuter
[u
] = dsdy
[u
] + dxOuter
* span
.texStepX
[u
][0];
1037 t0
= vLower
->texcoord
[u
][1] * invW
;
1038 tLeft
[u
] = t0
+ (span
.texStepX
[u
][1] * adjx
+ dtdy
[u
]
1039 * adjy
) * (1.0F
/FIXED_SCALE
);
1040 dtOuter
[u
] = dtdy
[u
] + dxOuter
* span
.texStepX
[u
][1];
1041 u0
= vLower
->texcoord
[u
][2] * invW
;
1042 uLeft
[u
] = u0
+ (span
.texStepX
[u
][2] * adjx
+ dudy
[u
]
1043 * adjy
) * (1.0F
/FIXED_SCALE
);
1044 duOuter
[u
] = dudy
[u
] + dxOuter
* span
.texStepX
[u
][2];
1045 v0
= vLower
->texcoord
[u
][3] * invW
;
1046 vLeft
[u
] = v0
+ (span
.texStepX
[u
][3] * adjx
+ dvdy
[u
]
1047 * adjy
) * (1.0F
/FIXED_SCALE
);
1048 dvOuter
[u
] = dvdy
[u
] + dxOuter
* span
.texStepX
[u
][3];
1057 if (setupRight
&& eRight
->lines
>0) {
1058 fxRightEdge
= eRight
->fsx
- FIXED_EPSILON
;
1059 fdxRightEdge
= eRight
->fdxdy
;
1067 /* Rasterize setup */
1068 #ifdef PIXEL_ADDRESS
1069 dPRowInner
= dPRowOuter
+ sizeof(PIXEL_TYPE
);
1073 dZRowInner
= dZRowOuter
+ sizeof(DEPTH_TYPE
);
1075 fdzInner
= fdzOuter
+ span
.zStep
;
1078 dfogInner
= dfogOuter
+ span
.fogStep
;
1080 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1081 fdrInner
= fdrOuter
+ span
.redStep
;
1082 fdgInner
= fdgOuter
+ span
.greenStep
;
1083 fdbInner
= fdbOuter
+ span
.blueStep
;
1085 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1086 fdaInner
= fdaOuter
+ span
.alphaStep
;
1088 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1089 fdsrInner
= fdsrOuter
+ span
.specRedStep
;
1090 fdsgInner
= fdsgOuter
+ span
.specGreenStep
;
1091 fdsbInner
= fdsbOuter
+ span
.specBlueStep
;
1094 fdiInner
= fdiOuter
+ span
.indexStep
;
1096 #ifdef INTERP_INT_TEX
1097 fdsInner
= fdsOuter
+ span
.intTexStep
[0];
1098 fdtInner
= fdtOuter
+ span
.intTexStep
[1];
1101 dsInner
= dsOuter
+ span
.texStepX
[0][0];
1102 dtInner
= dtOuter
+ span
.texStepX
[0][1];
1103 duInner
= duOuter
+ span
.texStepX
[0][2];
1104 dvInner
= dvOuter
+ span
.texStepX
[0][3];
1106 #ifdef INTERP_MULTITEX
1109 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1110 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1111 dsInner
[u
] = dsOuter
[u
] + span
.texStepX
[u
][0];
1112 dtInner
[u
] = dtOuter
[u
] + span
.texStepX
[u
][1];
1113 duInner
[u
] = duOuter
[u
] + span
.texStepX
[u
][2];
1114 dvInner
[u
] = dvOuter
[u
] + span
.texStepX
[u
][3];
1121 /* initialize the span interpolants to the leftmost value */
1122 /* ff = fixed-pt fragment */
1123 const GLint right
= FixedToInt(fxRightEdge
);
1125 span
.x
= FixedToInt(fxLeftEdge
);
1127 if (right
<= span
.x
)
1130 span
.end
= right
- span
.x
;
1138 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1143 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1146 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1148 span
.specGreen
= fsg
;
1149 span
.specBlue
= fsb
;
1154 #ifdef INTERP_INT_TEX
1155 span
.intTex
[0] = fs
;
1156 span
.intTex
[1] = ft
;
1160 span
.tex
[0][0] = sLeft
;
1161 span
.tex
[0][1] = tLeft
;
1162 span
.tex
[0][2] = uLeft
;
1163 span
.tex
[0][3] = vLeft
;
1166 #ifdef INTERP_MULTITEX
1169 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1170 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1171 span
.tex
[u
][0] = sLeft
[u
];
1172 span
.tex
[u
][1] = tLeft
[u
];
1173 span
.tex
[u
][2] = uLeft
[u
];
1174 span
.tex
[u
][3] = vLeft
[u
];
1182 /* need this to accomodate round-off errors */
1183 const GLint len
= right
- span
.x
- 1;
1184 GLfixed ffrend
= span
.red
+ len
* span
.redStep
;
1185 GLfixed ffgend
= span
.green
+ len
* span
.greenStep
;
1186 GLfixed ffbend
= span
.blue
+ len
* span
.blueStep
;
1193 span
.green
-= ffgend
;
1198 span
.blue
-= ffbend
;
1206 const GLint len
= right
- span
.x
- 1;
1207 GLfixed ffaend
= span
.alpha
+ len
* span
.alphaStep
;
1209 span
.alpha
-= ffaend
;
1217 /* need this to accomodate round-off errors */
1218 const GLint len
= right
- span
.x
- 1;
1219 GLfixed ffsrend
= span
.specRed
+ len
* span
.specRedStep
;
1220 GLfixed ffsgend
= span
.specGreen
+ len
* span
.specGreenStep
;
1221 GLfixed ffsbend
= span
.specBlue
+ len
* span
.specBlueStep
;
1223 span
.specRed
-= ffsrend
;
1224 if (span
.specRed
< 0)
1228 span
.specGreen
-= ffsgend
;
1229 if (span
.specGreen
< 0)
1233 span
.specBlue
-= ffsbend
;
1234 if (span
.specBlue
< 0)
1240 if (span
.index
< 0) span
.index
= 0;
1243 /* This is where we actually generate fragments */
1245 RENDER_SPAN( span
);
1249 * Advance to the next scan line. Compute the
1250 * new edge coordinates, and adjust the
1251 * pixel-center x coordinate so that it stays
1252 * on or inside the major edge.
1257 fxLeftEdge
+= fdxLeftEdge
;
1258 fxRightEdge
+= fdxRightEdge
;
1263 fError
-= FIXED_ONE
;
1264 #ifdef PIXEL_ADDRESS
1265 pRow
= (PIXEL_TYPE
*) ((GLubyte
*) pRow
+ dPRowOuter
);
1269 zRow
= (DEPTH_TYPE
*) ((GLubyte
*) zRow
+ dZRowOuter
);
1274 fogLeft
+= dfogOuter
;
1276 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1281 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1284 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1292 #ifdef INTERP_INT_TEX
1302 #ifdef INTERP_MULTITEX
1305 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1306 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1307 sLeft
[u
] += dsOuter
[u
];
1308 tLeft
[u
] += dtOuter
[u
];
1309 uLeft
[u
] += duOuter
[u
];
1310 vLeft
[u
] += dvOuter
[u
];
1317 #ifdef PIXEL_ADDRESS
1318 pRow
= (PIXEL_TYPE
*) ((GLubyte
*) pRow
+ dPRowInner
);
1322 zRow
= (DEPTH_TYPE
*) ((GLubyte
*) zRow
+ dZRowInner
);
1327 fogLeft
+= dfogInner
;
1329 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1334 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1337 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1345 #ifdef INTERP_INT_TEX
1355 #ifdef INTERP_MULTITEX
1358 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1359 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1360 sLeft
[u
] += dsInner
[u
];
1361 tLeft
[u
] += dtInner
[u
];
1362 uLeft
[u
] += duInner
[u
];
1363 vLeft
[u
] += dvInner
[u
];
1371 } /* for subTriangle */
1385 #undef BYTES_PER_ROW
1386 #undef PIXEL_ADDRESS
1394 #undef INTERP_INT_TEX
1396 #undef INTERP_MULTITEX
1397 #undef INTERP_FLOAT_RGBA
1398 #undef INTERP_FLOAT_SPEC
1405 #undef DO_OCCLUSION_TEST