1 /* $Id: s_tritemp.h,v 1.27 2001/09/19 20:30:44 kschultz 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.
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_LAMBDA - if defined, compute lambda value (for mipmapping)
47 * a lambda value for every texture unit
48 * INTERP_FLOAT_RGBA - if defined, interpolate RGBA with floating point
49 * INTERP_FLOAT_SPEC - if defined, interpolate specular with floating point
51 * When one can directly address pixels in the color buffer the following
52 * macros can be defined and used to compute pixel addresses during
53 * rasterization (see pRow):
54 * PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint)
55 * BYTES_PER_ROW - number of bytes per row in the color buffer
56 * PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where
57 * Y==0 at bottom of screen and increases upward.
59 * Similarly, for direct depth buffer access, this type is used for depth
61 * DEPTH_TYPE - either GLushort or GLuint
63 * Optionally, one may provide one-time setup code per triangle:
64 * SETUP_CODE - code which is to be executed once per triangle
65 * CLEANUP_CODE - code to execute at end of triangle
67 * The following macro MUST be defined:
68 * RENDER_SPAN(span) - code to write a span of pixels.
70 * This code was designed for the origin to be in the lower-left corner.
72 * Inspired by triangle rasterizer code written by Allen Akin. Thanks Allen!
77 * This is a bit of a hack, but it's a centralized place to enable floating-
78 * point color interpolation when GLchan is actually floating point.
80 #if CHAN_TYPE == GL_FLOAT
82 #if defined(INTERP_RGB)
85 #define INTERP_FLOAT_RGBA
88 #if defined(INTERP_SPEC)
90 #define INTERP_FLOAT_SPEC
96 /*void triangle( GLcontext *ctx, SWvertex *v0, SWvertex *v1, SWvertex *v2 )*/
99 const SWvertex
*v0
, *v1
; /* Y(v0) < Y(v1) */
100 GLfloat dx
; /* X(v1) - X(v0) */
101 GLfloat dy
; /* Y(v1) - Y(v0) */
102 GLfixed fdxdy
; /* dx/dy in fixed-point */
103 GLfixed fsx
; /* first sample point x coord */
105 GLfloat adjy
; /* adjust from v[0]->fy to fsy, scaled */
106 GLint lines
; /* number of lines to be sampled on this edge */
107 GLfixed fx0
; /* fixed pt X of lower endpoint */
111 const GLint depthBits
= ctx
->Visual
.depthBits
;
112 const GLint fixedToDepthShift
= depthBits
<= 16 ? FIXED_SHIFT
: 0;
113 const GLfloat maxDepth
= ctx
->DepthMaxF
;
114 #define FixedToDepth(F) ((F) >> fixedToDepthShift)
116 EdgeT eMaj
, eTop
, eBot
;
118 const SWvertex
*vMin
, *vMid
, *vMax
; /* Y(vMin)<=Y(vMid)<=Y(vMax) */
119 float bf
= SWRAST_CONTEXT(ctx
)->_backface_sign
;
120 const GLint snapMask
= ~((FIXED_ONE
/ 16) - 1); /* for x/y coord snapping */
121 GLfixed vMin_fx
, vMin_fy
, vMid_fx
, vMid_fy
, vMax_fx
, vMax_fy
;
123 struct triangle_span span
;
126 (void) fixedToDepthShift
;
129 /* Compute fixed point x,y coords w/ half-pixel offsets and snapping.
130 * And find the order of the 3 vertices along the Y axis.
133 const GLfixed fy0
= FloatToFixed(v0
->win
[1] - 0.5F
) & snapMask
;
134 const GLfixed fy1
= FloatToFixed(v1
->win
[1] - 0.5F
) & snapMask
;
135 const GLfixed fy2
= FloatToFixed(v2
->win
[1] - 0.5F
) & snapMask
;
140 vMin
= v0
; vMid
= v1
; vMax
= v2
;
141 vMin_fy
= fy0
; vMid_fy
= fy1
; vMax_fy
= fy2
;
143 else if (fy2
<= fy0
) {
145 vMin
= v2
; vMid
= v0
; vMax
= v1
;
146 vMin_fy
= fy2
; vMid_fy
= fy0
; vMax_fy
= fy1
;
150 vMin
= v0
; vMid
= v2
; vMax
= v1
;
151 vMin_fy
= fy0
; vMid_fy
= fy2
; vMax_fy
= fy1
;
158 vMin
= v1
; vMid
= v0
; vMax
= v2
;
159 vMin_fy
= fy1
; vMid_fy
= fy0
; vMax_fy
= fy2
;
162 else if (fy2
<= fy1
) {
164 vMin
= v2
; vMid
= v1
; vMax
= v0
;
165 vMin_fy
= fy2
; vMid_fy
= fy1
; vMax_fy
= fy0
;
170 vMin
= v1
; vMid
= v2
; vMax
= v0
;
171 vMin_fy
= fy1
; vMid_fy
= fy2
; vMax_fy
= fy0
;
175 /* fixed point X coords */
176 vMin_fx
= FloatToFixed(vMin
->win
[0] + 0.5F
) & snapMask
;
177 vMid_fx
= FloatToFixed(vMid
->win
[0] + 0.5F
) & snapMask
;
178 vMax_fx
= FloatToFixed(vMax
->win
[0] + 0.5F
) & snapMask
;
181 /* vertex/edge relationship */
182 eMaj
.v0
= vMin
; eMaj
.v1
= vMax
; /*TODO: .v1's not needed */
183 eTop
.v0
= vMid
; eTop
.v1
= vMax
;
184 eBot
.v0
= vMin
; eBot
.v1
= vMid
;
186 /* compute deltas for each edge: vertex[upper] - vertex[lower] */
187 eMaj
.dx
= FixedToFloat(vMax_fx
- vMin_fx
);
188 eMaj
.dy
= FixedToFloat(vMax_fy
- vMin_fy
);
189 eTop
.dx
= FixedToFloat(vMax_fx
- vMid_fx
);
190 eTop
.dy
= FixedToFloat(vMax_fy
- vMid_fy
);
191 eBot
.dx
= FixedToFloat(vMid_fx
- vMin_fx
);
192 eBot
.dy
= FixedToFloat(vMid_fy
- vMin_fy
);
194 /* compute area, oneOverArea and perform backface culling */
196 const GLfloat area
= eMaj
.dx
* eBot
.dy
- eBot
.dx
* eMaj
.dy
;
198 /* Do backface culling */
205 oneOverArea
= 1.0F
/ area
;
208 #ifndef DO_OCCLUSION_TEST
209 ctx
->OcclusionResult
= GL_TRUE
;
212 /* Edge setup. For a triangle strip these could be reused... */
214 eMaj
.fsy
= FixedCeil(vMin_fy
);
215 eMaj
.lines
= FixedToInt(FixedCeil(vMax_fy
- eMaj
.fsy
));
216 if (eMaj
.lines
> 0) {
217 GLfloat dxdy
= eMaj
.dx
/ eMaj
.dy
;
218 eMaj
.fdxdy
= SignedFloatToFixed(dxdy
);
219 eMaj
.adjy
= (GLfloat
) (eMaj
.fsy
- vMin_fy
); /* SCALED! */
221 eMaj
.fsx
= eMaj
.fx0
+ (GLfixed
) (eMaj
.adjy
* dxdy
);
227 eTop
.fsy
= FixedCeil(vMid_fy
);
228 eTop
.lines
= FixedToInt(FixedCeil(vMax_fy
- eTop
.fsy
));
229 if (eTop
.lines
> 0) {
230 GLfloat dxdy
= eTop
.dx
/ eTop
.dy
;
231 eTop
.fdxdy
= SignedFloatToFixed(dxdy
);
232 eTop
.adjy
= (GLfloat
) (eTop
.fsy
- vMid_fy
); /* SCALED! */
234 eTop
.fsx
= eTop
.fx0
+ (GLfixed
) (eTop
.adjy
* dxdy
);
237 eBot
.fsy
= FixedCeil(vMin_fy
);
238 eBot
.lines
= FixedToInt(FixedCeil(vMid_fy
- eBot
.fsy
));
239 if (eBot
.lines
> 0) {
240 GLfloat dxdy
= eBot
.dx
/ eBot
.dy
;
241 eBot
.fdxdy
= SignedFloatToFixed(dxdy
);
242 eBot
.adjy
= (GLfloat
) (eBot
.fsy
- vMin_fy
); /* SCALED! */
244 eBot
.fsx
= eBot
.fx0
+ (GLfixed
) (eBot
.adjy
* dxdy
);
249 * Conceptually, we view a triangle as two subtriangles
250 * separated by a perfectly horizontal line. The edge that is
251 * intersected by this line is one with maximal absolute dy; we
252 * call it a ``major'' edge. The other two edges are the
253 * ``top'' edge (for the upper subtriangle) and the ``bottom''
254 * edge (for the lower subtriangle). If either of these two
255 * edges is horizontal or very close to horizontal, the
256 * corresponding subtriangle might cover zero sample points;
257 * we take care to handle such cases, for performance as well
260 * By stepping rasterization parameters along the major edge,
261 * we can avoid recomputing them at the discontinuity where
262 * the top and bottom edges meet. However, this forces us to
263 * be able to scan both left-to-right and right-to-left.
264 * Also, we must determine whether the major edge is at the
265 * left or right side of the triangle. We do this by
266 * computing the magnitude of the cross-product of the major
267 * and top edges. Since this magnitude depends on the sine of
268 * the angle between the two edges, its sign tells us whether
269 * we turn to the left or to the right when travelling along
270 * the major edge to the top edge, and from this we infer
271 * whether the major edge is on the left or the right.
273 * Serendipitously, this cross-product magnitude is also a
274 * value we need to compute the iteration parameter
275 * derivatives for the triangle, and it can be used to perform
276 * backface culling because its sign tells us whether the
277 * triangle is clockwise or counterclockwise. In this code we
278 * refer to it as ``area'' because it's also proportional to
279 * the pixel area of the triangle.
283 GLint scan_from_left_to_right
; /* true if scanning left-to-right */
290 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
295 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
298 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
299 GLfloat dsrdx
, dsrdy
;
300 GLfloat dsgdx
, dsgdy
;
301 GLfloat dsbdx
, dsbdy
;
306 #ifdef INTERP_INT_TEX
316 #ifdef INTERP_MULTITEX
317 GLfloat dsdy
[MAX_TEXTURE_UNITS
];
318 GLfloat dtdy
[MAX_TEXTURE_UNITS
];
319 GLfloat dudy
[MAX_TEXTURE_UNITS
];
320 GLfloat dvdy
[MAX_TEXTURE_UNITS
];
323 #if defined(INTERP_LAMBDA) && !defined(INTERP_TEX) && !defined(INTERP_MULTITEX)
324 #error "Mipmapping without texturing doesn't make sense."
328 * Execute user-supplied setup code
334 scan_from_left_to_right
= (oneOverArea
< 0.0F
);
338 /* compute d?/dx and d?/dy derivatives */
340 span
.activeMask
|= SPAN_Z
;
342 GLfloat eMaj_dz
, eBot_dz
;
343 eMaj_dz
= vMax
->win
[2] - vMin
->win
[2];
344 eBot_dz
= vMid
->win
[2] - vMin
->win
[2];
345 dzdx
= oneOverArea
* (eMaj_dz
* eBot
.dy
- eMaj
.dy
* eBot_dz
);
346 if (dzdx
> maxDepth
|| dzdx
< -maxDepth
) {
347 /* probably a sliver triangle */
352 dzdy
= oneOverArea
* (eMaj
.dx
* eBot_dz
- eMaj_dz
* eBot
.dx
);
355 span
.zStep
= SignedFloatToFixed(dzdx
);
357 span
.zStep
= (GLint
) dzdx
;
361 span
.activeMask
|= SPAN_FOG
;
363 const GLfloat eMaj_dfog
= vMax
->fog
- vMin
->fog
;
364 const GLfloat eBot_dfog
= vMid
->fog
- vMin
->fog
;
365 span
.fogStep
= oneOverArea
* (eMaj_dfog
* eBot
.dy
- eMaj
.dy
* eBot_dfog
);
366 dfogdy
= oneOverArea
* (eMaj
.dx
* eBot_dfog
- eMaj_dfog
* eBot
.dx
);
370 span
.activeMask
|= SPAN_RGBA
;
371 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
372 GLfloat eMaj_dr
, eBot_dr
;
373 GLfloat eMaj_dg
, eBot_dg
;
374 GLfloat eMaj_db
, eBot_db
;
376 GLfloat eMaj_da
, eBot_da
;
378 eMaj_dr
= (GLfloat
) ((GLint
) vMax
->color
[RCOMP
] -
379 (GLint
) vMin
->color
[RCOMP
]);
380 eBot_dr
= (GLfloat
) ((GLint
) vMid
->color
[RCOMP
] -
381 (GLint
) vMin
->color
[RCOMP
]);
382 drdx
= oneOverArea
* (eMaj_dr
* eBot
.dy
- eMaj
.dy
* eBot_dr
);
383 span
.redStep
= SignedFloatToFixed(drdx
);
384 drdy
= oneOverArea
* (eMaj
.dx
* eBot_dr
- eMaj_dr
* eBot
.dx
);
385 eMaj_dg
= (GLfloat
) ((GLint
) vMax
->color
[GCOMP
] -
386 (GLint
) vMin
->color
[GCOMP
]);
387 eBot_dg
= (GLfloat
) ((GLint
) vMid
->color
[GCOMP
] -
388 (GLint
) vMin
->color
[GCOMP
]);
389 dgdx
= oneOverArea
* (eMaj_dg
* eBot
.dy
- eMaj
.dy
* eBot_dg
);
390 span
.greenStep
= SignedFloatToFixed(dgdx
);
391 dgdy
= oneOverArea
* (eMaj
.dx
* eBot_dg
- eMaj_dg
* eBot
.dx
);
392 eMaj_db
= (GLfloat
) ((GLint
) vMax
->color
[BCOMP
] -
393 (GLint
) vMin
->color
[BCOMP
]);
394 eBot_db
= (GLfloat
) ((GLint
) vMid
->color
[BCOMP
] -
395 (GLint
) vMin
->color
[BCOMP
]);
396 dbdx
= oneOverArea
* (eMaj_db
* eBot
.dy
- eMaj
.dy
* eBot_db
);
397 span
.blueStep
= SignedFloatToFixed(dbdx
);
398 dbdy
= oneOverArea
* (eMaj
.dx
* eBot_db
- eMaj_db
* eBot
.dx
);
400 eMaj_da
= (GLfloat
) ((GLint
) vMax
->color
[ACOMP
] -
401 (GLint
) vMin
->color
[ACOMP
]);
402 eBot_da
= (GLfloat
) ((GLint
) vMid
->color
[ACOMP
] -
403 (GLint
) vMin
->color
[ACOMP
]);
404 dadx
= oneOverArea
* (eMaj_da
* eBot
.dy
- eMaj
.dy
* eBot_da
);
405 span
.alphaStep
= SignedFloatToFixed(dadx
);
406 dady
= oneOverArea
* (eMaj
.dx
* eBot_da
- eMaj_da
* eBot
.dx
);
410 ASSERT (ctx
->Light
.ShadeModel
== GL_FLAT
);
411 span
.activeMask
|= SPAN_FLAT
;
424 #ifdef INTERP_FLOAT_RGBA
425 span
.activeMask
|= SPAN_RGBA
;
426 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
427 GLfloat eMaj_dr
, eBot_dr
;
428 GLfloat eMaj_dg
, eBot_dg
;
429 GLfloat eMaj_db
, eBot_db
;
430 GLfloat eMaj_da
, eBot_da
;
431 eMaj_dr
= vMax
->color
[RCOMP
] - vMin
->color
[RCOMP
];
432 eBot_dr
= vMid
->color
[RCOMP
] - vMin
->color
[RCOMP
];
433 drdx
= oneOverArea
* (eMaj_dr
* eBot
.dy
- eMaj
.dy
* eBot_dr
);
435 drdy
= oneOverArea
* (eMaj
.dx
* eBot_dr
- eMaj_dr
* eBot
.dx
);
436 eMaj_dg
= vMax
->color
[GCOMP
] - vMin
->color
[GCOMP
];
437 eBot_dg
= vMid
->color
[GCOMP
] - vMin
->color
[GCOMP
];
438 dgdx
= oneOverArea
* (eMaj_dg
* eBot
.dy
- eMaj
.dy
* eBot_dg
);
439 span
.greenStep
= dgdx
;
440 dgdy
= oneOverArea
* (eMaj
.dx
* eBot_dg
- eMaj_dg
* eBot
.dx
);
441 eMaj_db
= vMax
->color
[BCOMP
] - vMin
->color
[BCOMP
];
442 eBot_db
= vMid
->color
[BCOMP
] - vMin
->color
[BCOMP
];
443 dbdx
= oneOverArea
* (eMaj_db
* eBot
.dy
- eMaj
.dy
* eBot_db
);
444 span
.blueStep
= dbdx
;
445 dbdy
= oneOverArea
* (eMaj
.dx
* eBot_db
- eMaj_db
* eBot
.dx
);
446 eMaj_da
= vMax
->color
[ACOMP
] - vMin
->color
[ACOMP
];
447 eBot_da
= vMid
->color
[ACOMP
] - vMin
->color
[ACOMP
];
448 dadx
= oneOverArea
* (eMaj_da
* eBot
.dy
- eMaj
.dy
* eBot_da
);
449 span
.alphaStep
= dadx
;
450 dady
= oneOverArea
* (eMaj
.dx
* eBot_da
- eMaj_da
* eBot
.dx
);
453 drdx
= drdy
= span
.redStep
= 0.0F
;
454 dgdx
= dgdy
= span
.greenStep
= 0.0F
;
455 dbdx
= dbdy
= span
.blueStep
= 0.0F
;
456 dadx
= dady
= span
.alphaStep
= 0.0F
;
460 span
.activeMask
|= SPAN_SPEC
;
461 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
462 GLfloat eMaj_dsr
, eBot_dsr
;
463 GLfloat eMaj_dsg
, eBot_dsg
;
464 GLfloat eMaj_dsb
, eBot_dsb
;
465 eMaj_dsr
= (GLfloat
) ((GLint
) vMax
->specular
[RCOMP
] -
466 (GLint
) vMin
->specular
[RCOMP
]);
467 eBot_dsr
= (GLfloat
) ((GLint
) vMid
->specular
[RCOMP
] -
468 (GLint
) vMin
->specular
[RCOMP
]);
469 dsrdx
= oneOverArea
* (eMaj_dsr
* eBot
.dy
- eMaj
.dy
* eBot_dsr
);
470 span
.specRedStep
= SignedFloatToFixed(dsrdx
);
471 dsrdy
= oneOverArea
* (eMaj
.dx
* eBot_dsr
- eMaj_dsr
* eBot
.dx
);
472 eMaj_dsg
= (GLfloat
) ((GLint
) vMax
->specular
[GCOMP
] -
473 (GLint
) vMin
->specular
[GCOMP
]);
474 eBot_dsg
= (GLfloat
) ((GLint
) vMid
->specular
[GCOMP
] -
475 (GLint
) vMin
->specular
[GCOMP
]);
476 dsgdx
= oneOverArea
* (eMaj_dsg
* eBot
.dy
- eMaj
.dy
* eBot_dsg
);
477 span
.specGreenStep
= SignedFloatToFixed(dsgdx
);
478 dsgdy
= oneOverArea
* (eMaj
.dx
* eBot_dsg
- eMaj_dsg
* eBot
.dx
);
479 eMaj_dsb
= (GLfloat
) ((GLint
) vMax
->specular
[BCOMP
] -
480 (GLint
) vMin
->specular
[BCOMP
]);
481 eBot_dsb
= (GLfloat
) ((GLint
) vMid
->specular
[BCOMP
] -
482 (GLint
) vMin
->specular
[BCOMP
]);
483 dsbdx
= oneOverArea
* (eMaj_dsb
* eBot
.dy
- eMaj
.dy
* eBot_dsb
);
484 span
.specBlueStep
= SignedFloatToFixed(dsbdx
);
485 dsbdy
= oneOverArea
* (eMaj
.dx
* eBot_dsb
- eMaj_dsb
* eBot
.dx
);
488 dsrdx
= dsrdy
= 0.0F
;
489 dsgdx
= dsgdy
= 0.0F
;
490 dsbdx
= dsbdy
= 0.0F
;
491 span
.specRedStep
= 0;
492 span
.specGreenStep
= 0;
493 span
.specBlueStep
= 0;
496 #ifdef INTERP_FLOAT_SPEC
497 span
.activeMask
|= SPAN_SPEC
;
498 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
499 GLfloat eMaj_dsr
, eBot_dsr
;
500 GLfloat eMaj_dsg
, eBot_dsg
;
501 GLfloat eMaj_dsb
, eBot_dsb
;
502 eMaj_dsr
= vMax
->specular
[RCOMP
] - vMin
->specular
[RCOMP
];
503 eBot_dsr
= vMid
->specular
[RCOMP
] - vMin
->specular
[RCOMP
];
504 dsrdx
= oneOverArea
* (eMaj_dsr
* eBot
.dy
- eMaj
.dy
* eBot_dsr
);
505 span
.specRedStep
= dsrdx
;
506 dsrdy
= oneOverArea
* (eMaj
.dx
* eBot_dsr
- eMaj_dsr
* eBot
.dx
);
507 eMaj_dsg
= vMax
->specular
[GCOMP
] - vMin
->specular
[GCOMP
];
508 eBot_dsg
= vMid
->specular
[GCOMP
] - vMin
->specular
[GCOMP
];
509 dsgdx
= oneOverArea
* (eMaj_dsg
* eBot
.dy
- eMaj
.dy
* eBot_dsg
);
510 span
.specGreenStep
= dsgdx
;
511 dsgdy
= oneOverArea
* (eMaj
.dx
* eBot_dsg
- eMaj_dsg
* eBot
.dx
);
512 eMaj_dsb
= vMax
->specular
[BCOMP
] - vMin
->specular
[BCOMP
];
513 eBot_dsb
= vMid
->specular
[BCOMP
] - vMin
->specular
[BCOMP
];
514 dsbdx
= oneOverArea
* (eMaj_dsb
* eBot
.dy
- eMaj
.dy
* eBot_dsb
);
515 span
.specBlueStep
= dsbdx
;
516 dsbdy
= oneOverArea
* (eMaj
.dx
* eBot_dsb
- eMaj_dsb
* eBot
.dx
);
519 dsrdx
= dsrdy
= span
.specRedStep
= 0;
520 dsgdx
= dsgdy
= span
.specGreenStep
= 0;
521 dsbdx
= dsbdy
= span
.specBlueStep
= 0;
525 span
.activeMask
|= SPAN_INDEX
;
526 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
527 GLfloat eMaj_di
, eBot_di
;
528 eMaj_di
= (GLfloat
) ((GLint
) vMax
->index
- (GLint
) vMin
->index
);
529 eBot_di
= (GLfloat
) ((GLint
) vMid
->index
- (GLint
) vMin
->index
);
530 didx
= oneOverArea
* (eMaj_di
* eBot
.dy
- eMaj
.dy
* eBot_di
);
531 span
.indexStep
= SignedFloatToFixed(didx
);
532 didy
= oneOverArea
* (eMaj
.dx
* eBot_di
- eMaj_di
* eBot
.dx
);
535 span
.activeMask
|= SPAN_FLAT
;
540 #ifdef INTERP_INT_TEX
541 span
.activeMask
|= SPAN_INT_TEXTURE
;
543 GLfloat eMaj_ds
, eBot_ds
;
544 eMaj_ds
= (vMax
->texcoord
[0][0] - vMin
->texcoord
[0][0]) * S_SCALE
;
545 eBot_ds
= (vMid
->texcoord
[0][0] - vMin
->texcoord
[0][0]) * S_SCALE
;
546 dsdx
= oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
547 span
.intTexStep
[0] = SignedFloatToFixed(dsdx
);
548 dsdy
= oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
551 GLfloat eMaj_dt
, eBot_dt
;
552 eMaj_dt
= (vMax
->texcoord
[0][1] - vMin
->texcoord
[0][1]) * T_SCALE
;
553 eBot_dt
= (vMid
->texcoord
[0][1] - vMin
->texcoord
[0][1]) * T_SCALE
;
554 dtdx
= oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
555 span
.intTexStep
[1] = SignedFloatToFixed(dtdx
);
556 dtdy
= oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
561 span
.activeMask
|= SPAN_TEXTURE
;
563 GLfloat wMax
= vMax
->win
[3];
564 GLfloat wMin
= vMin
->win
[3];
565 GLfloat wMid
= vMid
->win
[3];
566 GLfloat eMaj_ds
, eBot_ds
;
567 GLfloat eMaj_dt
, eBot_dt
;
568 GLfloat eMaj_du
, eBot_du
;
569 GLfloat eMaj_dv
, eBot_dv
;
571 eMaj_ds
= vMax
->texcoord
[0][0] * wMax
- vMin
->texcoord
[0][0] * wMin
;
572 eBot_ds
= vMid
->texcoord
[0][0] * wMid
- vMin
->texcoord
[0][0] * wMin
;
573 span
.texStep
[0][0] = oneOverArea
* (eMaj_ds
* eBot
.dy
574 - eMaj
.dy
* eBot_ds
);
575 dsdy
= oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
577 eMaj_dt
= vMax
->texcoord
[0][1] * wMax
- vMin
->texcoord
[0][1] * wMin
;
578 eBot_dt
= vMid
->texcoord
[0][1] * wMid
- vMin
->texcoord
[0][1] * wMin
;
579 span
.texStep
[0][1] = oneOverArea
* (eMaj_dt
* eBot
.dy
580 - eMaj
.dy
* eBot_dt
);
581 dtdy
= oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
583 eMaj_du
= vMax
->texcoord
[0][2] * wMax
- vMin
->texcoord
[0][2] * wMin
;
584 eBot_du
= vMid
->texcoord
[0][2] * wMid
- vMin
->texcoord
[0][2] * wMin
;
585 span
.texStep
[0][2] = oneOverArea
* (eMaj_du
* eBot
.dy
586 - eMaj
.dy
* eBot_du
);
587 dudy
= oneOverArea
* (eMaj
.dx
* eBot_du
- eMaj_du
* eBot
.dx
);
589 eMaj_dv
= vMax
->texcoord
[0][3] * wMax
- vMin
->texcoord
[0][3] * wMin
;
590 eBot_dv
= vMid
->texcoord
[0][3] * wMid
- vMin
->texcoord
[0][3] * wMin
;
591 span
.texStep
[0][3] = oneOverArea
* (eMaj_dv
* eBot
.dy
592 - eMaj
.dy
* eBot_dv
);
593 dvdy
= oneOverArea
* (eMaj
.dx
* eBot_dv
- eMaj_dv
* eBot
.dx
);
595 # ifdef INTERP_LAMBDA
597 GLfloat dudx
= span
.texStep
[0][0] * span
.texWidth
[0];
598 GLfloat dudy
= dsdy
* span
.texWidth
[0];
599 GLfloat dvdx
= span
.texStep
[0][1] * span
.texHeight
[0];
600 GLfloat dvdy
= dtdy
* span
.texHeight
[0];
601 GLfloat r1
= dudx
* dudx
+ dudy
* dudy
;
602 GLfloat r2
= dvdx
* dvdx
+ dvdy
* dvdy
;
603 span
.rho
[0] = r1
+ r2
; /* was rho2 = MAX2(r1,r2) */
604 span
.activeMask
|= SPAN_LAMBDA
;
608 #ifdef INTERP_MULTITEX
609 span
.activeMask
|= SPAN_TEXTURE
;
610 # ifdef INTERP_LAMBDA
611 span
.activeMask
|= SPAN_LAMBDA
;
614 GLfloat wMax
= vMax
->win
[3];
615 GLfloat wMin
= vMin
->win
[3];
616 GLfloat wMid
= vMid
->win
[3];
618 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
619 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
620 GLfloat eMaj_ds
, eBot_ds
;
621 GLfloat eMaj_dt
, eBot_dt
;
622 GLfloat eMaj_du
, eBot_du
;
623 GLfloat eMaj_dv
, eBot_dv
;
624 eMaj_ds
= vMax
->texcoord
[u
][0] * wMax
625 - vMin
->texcoord
[u
][0] * wMin
;
626 eBot_ds
= vMid
->texcoord
[u
][0] * wMid
627 - vMin
->texcoord
[u
][0] * wMin
;
628 span
.texStep
[u
][0] = oneOverArea
* (eMaj_ds
* eBot
.dy
629 - eMaj
.dy
* eBot_ds
);
630 dsdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
632 eMaj_dt
= vMax
->texcoord
[u
][1] * wMax
633 - vMin
->texcoord
[u
][1] * wMin
;
634 eBot_dt
= vMid
->texcoord
[u
][1] * wMid
635 - vMin
->texcoord
[u
][1] * wMin
;
636 span
.texStep
[u
][1] = oneOverArea
* (eMaj_dt
* eBot
.dy
637 - eMaj
.dy
* eBot_dt
);
638 dtdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
640 eMaj_du
= vMax
->texcoord
[u
][2] * wMax
641 - vMin
->texcoord
[u
][2] * wMin
;
642 eBot_du
= vMid
->texcoord
[u
][2] * wMid
643 - vMin
->texcoord
[u
][2] * wMin
;
644 span
.texStep
[u
][2] = oneOverArea
* (eMaj_du
* eBot
.dy
645 - eMaj
.dy
* eBot_du
);
646 dudy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_du
- eMaj_du
* eBot
.dx
);
648 eMaj_dv
= vMax
->texcoord
[u
][3] * wMax
649 - vMin
->texcoord
[u
][3] * wMin
;
650 eBot_dv
= vMid
->texcoord
[u
][3] * wMid
651 - vMin
->texcoord
[u
][3] * wMin
;
652 span
.texStep
[u
][3] = oneOverArea
* (eMaj_dv
* eBot
.dy
653 - eMaj
.dy
* eBot_dv
);
654 dvdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_dv
- eMaj_dv
* eBot
.dx
);
655 # ifdef INTERP_LAMBDA
657 GLfloat dudx
= span
.texStep
[u
][0] * span
.texWidth
[u
];
658 GLfloat dudy
= dsdy
[u
] * span
.texWidth
[u
];
659 GLfloat dvdx
= span
.texStep
[u
][1] * span
.texHeight
[u
];
660 GLfloat dvdy
= dtdy
[u
] * span
.texHeight
[u
];
661 GLfloat r1
= dudx
* dudx
+ dudy
* dudy
;
662 GLfloat r2
= dvdx
* dvdx
+ dvdy
* dvdy
;
663 span
.rho
[u
] = r1
+ r2
; /* was rho2 = MAX2(r1,r2) */
672 * We always sample at pixel centers. However, we avoid
673 * explicit half-pixel offsets in this code by incorporating
674 * the proper offset in each of x and y during the
675 * transformation to window coordinates.
677 * We also apply the usual rasterization rules to prevent
678 * cracks and overlaps. A pixel is considered inside a
679 * subtriangle if it meets all of four conditions: it is on or
680 * to the right of the left edge, strictly to the left of the
681 * right edge, on or below the top edge, and strictly above
682 * the bottom edge. (Some edges may be degenerate.)
684 * The following discussion assumes left-to-right scanning
685 * (that is, the major edge is on the left); the right-to-left
686 * case is a straightforward variation.
688 * We start by finding the half-integral y coordinate that is
689 * at or below the top of the triangle. This gives us the
690 * first scan line that could possibly contain pixels that are
691 * inside the triangle.
693 * Next we creep down the major edge until we reach that y,
694 * and compute the corresponding x coordinate on the edge.
695 * Then we find the half-integral x that lies on or just
696 * inside the edge. This is the first pixel that might lie in
697 * the interior of the triangle. (We won't know for sure
698 * until we check the other edges.)
700 * As we rasterize the triangle, we'll step down the major
701 * edge. For each step in y, we'll move an integer number
702 * of steps in x. There are two possible x step sizes, which
703 * we'll call the ``inner'' step (guaranteed to land on the
704 * edge or inside it) and the ``outer'' step (guaranteed to
705 * land on the edge or outside it). The inner and outer steps
706 * differ by one. During rasterization we maintain an error
707 * term that indicates our distance from the true edge, and
708 * select either the inner step or the outer step, whichever
709 * gets us to the first pixel that falls inside the triangle.
711 * All parameters (z, red, etc.) as well as the buffer
712 * addresses for color and z have inner and outer step values,
713 * so that we can increment them appropriately. This method
714 * eliminates the need to adjust parameters by creeping a
715 * sub-pixel amount into the triangle at each scanline.
721 GLfixed fxLeftEdge
, fxRightEdge
, fdxLeftEdge
, fdxRightEdge
;
725 GLfixed fError
, fdError
;
730 int dPRowOuter
, dPRowInner
; /* offset in bytes */
735 int dZRowOuter
, dZRowInner
; /* offset in bytes */
737 GLfixed fz
, fdzOuter
, fdzInner
;
740 GLfloat fogLeft
, dfogOuter
, dfogInner
;
743 GLfixed fr
, fdrOuter
, fdrInner
;
744 GLfixed fg
, fdgOuter
, fdgInner
;
745 GLfixed fb
, fdbOuter
, fdbInner
;
748 GLfixed fa
, fdaOuter
, fdaInner
;
750 #ifdef INTERP_FLOAT_RGBA
751 GLfloat fr
, fdrOuter
, fdrInner
;
752 GLfloat fg
, fdgOuter
, fdgInner
;
753 GLfloat fb
, fdbOuter
, fdbInner
;
754 GLfloat fa
, fdaOuter
, fdaInner
;
757 GLfixed fsr
=0, fdsrOuter
=0, fdsrInner
;
758 GLfixed fsg
=0, fdsgOuter
=0, fdsgInner
;
759 GLfixed fsb
=0, fdsbOuter
=0, fdsbInner
;
761 #ifdef INTERP_FLOAT_SPEC
762 GLfloat fsr
=0, fdsrOuter
=0, fdsrInner
;
763 GLfloat fsg
=0, fdsgOuter
=0, fdsgInner
;
764 GLfloat fsb
=0, fdsbOuter
=0, fdsbInner
;
767 GLfixed fi
=0, fdiOuter
=0, fdiInner
;
769 #ifdef INTERP_INT_TEX
770 GLfixed fs
=0, fdsOuter
=0, fdsInner
;
771 GLfixed ft
=0, fdtOuter
=0, fdtInner
;
774 GLfloat sLeft
=0, dsOuter
=0, dsInner
;
775 GLfloat tLeft
=0, dtOuter
=0, dtInner
;
776 GLfloat uLeft
=0, duOuter
=0, duInner
;
777 GLfloat vLeft
=0, dvOuter
=0, dvInner
;
779 #ifdef INTERP_MULTITEX
780 GLfloat sLeft
[MAX_TEXTURE_UNITS
];
781 GLfloat tLeft
[MAX_TEXTURE_UNITS
];
782 GLfloat uLeft
[MAX_TEXTURE_UNITS
];
783 GLfloat vLeft
[MAX_TEXTURE_UNITS
];
784 GLfloat dsOuter
[MAX_TEXTURE_UNITS
], dsInner
[MAX_TEXTURE_UNITS
];
785 GLfloat dtOuter
[MAX_TEXTURE_UNITS
], dtInner
[MAX_TEXTURE_UNITS
];
786 GLfloat duOuter
[MAX_TEXTURE_UNITS
], duInner
[MAX_TEXTURE_UNITS
];
787 GLfloat dvOuter
[MAX_TEXTURE_UNITS
], dvInner
[MAX_TEXTURE_UNITS
];
790 for (subTriangle
=0; subTriangle
<=1; subTriangle
++) {
791 EdgeT
*eLeft
, *eRight
;
792 int setupLeft
, setupRight
;
795 if (subTriangle
==0) {
797 if (scan_from_left_to_right
) {
800 lines
= eRight
->lines
;
807 lines
= eLeft
->lines
;
814 if (scan_from_left_to_right
) {
817 lines
= eRight
->lines
;
824 lines
= eLeft
->lines
;
832 if (setupLeft
&& eLeft
->lines
> 0) {
833 const SWvertex
*vLower
;
834 GLfixed fsx
= eLeft
->fsx
;
836 fError
= fx
- fsx
- FIXED_ONE
;
837 fxLeftEdge
= fsx
- FIXED_EPSILON
;
838 fdxLeftEdge
= eLeft
->fdxdy
;
839 fdxOuter
= FixedFloor(fdxLeftEdge
- FIXED_EPSILON
);
840 fdError
= fdxOuter
- fdxLeftEdge
+ FIXED_ONE
;
841 idxOuter
= FixedToInt(fdxOuter
);
842 dxOuter
= (float) idxOuter
;
846 span
.y
= FixedToInt(fy
);
848 adjx
= (float)(fx
- eLeft
->fx0
); /* SCALED! */
849 adjy
= eLeft
->adjy
; /* SCALED! */
850 (void) adjx
; /* silence compiler warnings */
851 (void) adjy
; /* silence compiler warnings */
854 (void) vLower
; /* silence compiler warnings */
858 pRow
= (PIXEL_TYPE
*) PIXEL_ADDRESS(FixedToInt(fxLeftEdge
), span
.y
);
859 dPRowOuter
= -((int)BYTES_PER_ROW
) + idxOuter
* sizeof(PIXEL_TYPE
);
860 /* negative because Y=0 at bottom and increases upward */
864 * Now we need the set of parameter (z, color, etc.) values at
865 * the point (fx, fy). This gives us properly-sampled parameter
866 * values that we can step from pixel to pixel. Furthermore,
867 * although we might have intermediate results that overflow
868 * the normal parameter range when we step temporarily outside
869 * the triangle, we shouldn't overflow or underflow for any
870 * pixel that's actually inside the triangle.
875 GLfloat z0
= vLower
->win
[2];
876 if (depthBits
<= 16) {
877 /* interpolate fixed-pt values */
878 GLfloat tmp
= (z0
* FIXED_SCALE
+
879 dzdx
* adjx
+ dzdy
* adjy
) + FIXED_HALF
;
880 if (tmp
< MAX_GLUINT
/ 2)
884 fdzOuter
= SignedFloatToFixed(dzdy
+ dxOuter
* dzdx
);
887 /* interpolate depth values exactly */
888 fz
= (GLint
) (z0
+ dzdx
* FixedToFloat(adjx
)
889 + dzdy
* FixedToFloat(adjy
));
890 fdzOuter
= (GLint
) (dzdy
+ dxOuter
* dzdx
);
893 zRow
= (DEPTH_TYPE
*)
894 _mesa_zbuffer_address(ctx
, FixedToInt(fxLeftEdge
), span
.y
);
895 dZRowOuter
= (ctx
->DrawBuffer
->Width
+ idxOuter
) * sizeof(DEPTH_TYPE
);
900 fogLeft
= vLower
->fog
+ (span
.fogStep
* adjx
+ dfogdy
* adjy
)
901 * (1.0F
/FIXED_SCALE
);
902 dfogOuter
= dfogdy
+ dxOuter
* span
.fogStep
;
905 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
906 fr
= (GLfixed
) (ChanToFixed(vLower
->color
[RCOMP
])
907 + drdx
* adjx
+ drdy
* adjy
) + FIXED_HALF
;
908 fdrOuter
= SignedFloatToFixed(drdy
+ dxOuter
* drdx
);
909 fg
= (GLfixed
) (ChanToFixed(vLower
->color
[GCOMP
])
910 + dgdx
* adjx
+ dgdy
* adjy
) + FIXED_HALF
;
911 fdgOuter
= SignedFloatToFixed(dgdy
+ dxOuter
* dgdx
);
912 fb
= (GLfixed
) (ChanToFixed(vLower
->color
[BCOMP
])
913 + dbdx
* adjx
+ dbdy
* adjy
) + FIXED_HALF
;
914 fdbOuter
= SignedFloatToFixed(dbdy
+ dxOuter
* dbdx
);
916 fa
= (GLfixed
) (ChanToFixed(vLower
->color
[ACOMP
])
917 + dadx
* adjx
+ dady
* adjy
) + FIXED_HALF
;
918 fdaOuter
= SignedFloatToFixed(dady
+ dxOuter
* dadx
);
922 ASSERT (ctx
->Light
.ShadeModel
== GL_FLAT
);
923 fr
= ChanToFixed(v2
->color
[RCOMP
]);
924 fg
= ChanToFixed(v2
->color
[GCOMP
]);
925 fb
= ChanToFixed(v2
->color
[BCOMP
]);
926 fdrOuter
= fdgOuter
= fdbOuter
= 0;
928 fa
= ChanToFixed(v2
->color
[ACOMP
]);
933 #ifdef INTERP_FLOAT_RGBA
934 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
935 fr
= vLower
->color
[RCOMP
]
936 + (drdx
* adjx
+ drdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
937 fdrOuter
= drdy
+ dxOuter
* drdx
;
938 fg
= vLower
->color
[GCOMP
]
939 + (dgdx
* adjx
+ dgdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
940 fdgOuter
= dgdy
+ dxOuter
* dgdx
;
941 fb
= vLower
->color
[BCOMP
]
942 + (dbdx
* adjx
+ dbdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
943 fdbOuter
= dbdy
+ dxOuter
* dbdx
;
944 fa
= vLower
->color
[ACOMP
]
945 + (dadx
* adjx
+ dady
* adjy
) * (1.0F
/ FIXED_SCALE
);
946 fdaOuter
= dady
+ dxOuter
* dadx
;
949 fr
= v2
->color
[RCOMP
];
950 fg
= v2
->color
[GCOMP
];
951 fb
= v2
->color
[BCOMP
];
952 fa
= v2
->color
[ACOMP
];
953 fdrOuter
= fdgOuter
= fdbOuter
= fdaOuter
= 0.0F
;
957 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
958 fsr
= (GLfixed
) (ChanToFixed(vLower
->specular
[RCOMP
])
959 + dsrdx
* adjx
+ dsrdy
* adjy
) + FIXED_HALF
;
960 fdsrOuter
= SignedFloatToFixed(dsrdy
+ dxOuter
* dsrdx
);
961 fsg
= (GLfixed
) (ChanToFixed(vLower
->specular
[GCOMP
])
962 + dsgdx
* adjx
+ dsgdy
* adjy
) + FIXED_HALF
;
963 fdsgOuter
= SignedFloatToFixed(dsgdy
+ dxOuter
* dsgdx
);
964 fsb
= (GLfixed
) (ChanToFixed(vLower
->specular
[BCOMP
])
965 + dsbdx
* adjx
+ dsbdy
* adjy
) + FIXED_HALF
;
966 fdsbOuter
= SignedFloatToFixed(dsbdy
+ dxOuter
* dsbdx
);
969 fsr
= ChanToFixed(v2
->specular
[RCOMP
]);
970 fsg
= ChanToFixed(v2
->specular
[GCOMP
]);
971 fsb
= ChanToFixed(v2
->specular
[BCOMP
]);
972 fdsrOuter
= fdsgOuter
= fdsbOuter
= 0;
975 #ifdef INTERP_FLOAT_SPEC
976 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
977 fsr
= vLower
->specular
[RCOMP
]
978 + (dsrdx
* adjx
+ dsrdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
979 fdsrOuter
= dsrdy
+ dxOuter
* dsrdx
;
980 fsg
= vLower
->specular
[GCOMP
]
981 + (dsgdx
* adjx
+ dsgdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
982 fdsgOuter
= dsgdy
+ dxOuter
* dsgdx
;
983 fsb
= vLower
->specular
[BCOMP
]
984 + (dsbdx
* adjx
+ dsbdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
985 fdsbOuter
= dsbdy
+ dxOuter
* dsbdx
;
988 fsr
= v2
->specular
[RCOMP
];
989 fsg
= v2
->specular
[GCOMP
];
990 fsb
= v2
->specular
[BCOMP
];
991 fdsrOuter
= fdsgOuter
= fdsbOuter
= 0.0F
;
995 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
996 fi
= (GLfixed
)(vLower
->index
* FIXED_SCALE
997 + didx
* adjx
+ didy
* adjy
) + FIXED_HALF
;
998 fdiOuter
= SignedFloatToFixed(didy
+ dxOuter
* didx
);
1001 fi
= (GLfixed
) (v2
->index
* FIXED_SCALE
);
1005 #ifdef INTERP_INT_TEX
1008 s0
= vLower
->texcoord
[0][0] * S_SCALE
;
1009 fs
= (GLfixed
)(s0
* FIXED_SCALE
+ dsdx
* adjx
1010 + dsdy
* adjy
) + FIXED_HALF
;
1011 fdsOuter
= SignedFloatToFixed(dsdy
+ dxOuter
* dsdx
);
1013 t0
= vLower
->texcoord
[0][1] * T_SCALE
;
1014 ft
= (GLfixed
)(t0
* FIXED_SCALE
+ dtdx
* adjx
1015 + dtdy
* adjy
) + FIXED_HALF
;
1016 fdtOuter
= SignedFloatToFixed(dtdy
+ dxOuter
* dtdx
);
1021 GLfloat invW
= vLower
->win
[3];
1022 GLfloat s0
, t0
, u0
, v0
;
1023 s0
= vLower
->texcoord
[0][0] * invW
;
1024 sLeft
= s0
+ (span
.texStep
[0][0] * adjx
+ dsdy
* adjy
)
1025 * (1.0F
/FIXED_SCALE
);
1026 dsOuter
= dsdy
+ dxOuter
* span
.texStep
[0][0];
1027 t0
= vLower
->texcoord
[0][1] * invW
;
1028 tLeft
= t0
+ (span
.texStep
[0][1] * adjx
+ dtdy
* adjy
)
1029 * (1.0F
/FIXED_SCALE
);
1030 dtOuter
= dtdy
+ dxOuter
* span
.texStep
[0][1];
1031 u0
= vLower
->texcoord
[0][2] * invW
;
1032 uLeft
= u0
+ (span
.texStep
[0][2] * adjx
+ dudy
* adjy
)
1033 * (1.0F
/FIXED_SCALE
);
1034 duOuter
= dudy
+ dxOuter
* span
.texStep
[0][2];
1035 v0
= vLower
->texcoord
[0][3] * invW
;
1036 vLeft
= v0
+ (span
.texStep
[0][3] * adjx
+ dvdy
* adjy
)
1037 * (1.0F
/FIXED_SCALE
);
1038 dvOuter
= dvdy
+ dxOuter
* span
.texStep
[0][3];
1041 #ifdef INTERP_MULTITEX
1044 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1045 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1046 GLfloat invW
= vLower
->win
[3];
1047 GLfloat s0
, t0
, u0
, v0
;
1048 s0
= vLower
->texcoord
[u
][0] * invW
;
1049 sLeft
[u
] = s0
+ (span
.texStep
[u
][0] * adjx
+ dsdy
[u
]
1050 * adjy
) * (1.0F
/FIXED_SCALE
);
1051 dsOuter
[u
] = dsdy
[u
] + dxOuter
* span
.texStep
[u
][0];
1052 t0
= vLower
->texcoord
[u
][1] * invW
;
1053 tLeft
[u
] = t0
+ (span
.texStep
[u
][1] * adjx
+ dtdy
[u
]
1054 * adjy
) * (1.0F
/FIXED_SCALE
);
1055 dtOuter
[u
] = dtdy
[u
] + dxOuter
* span
.texStep
[u
][1];
1056 u0
= vLower
->texcoord
[u
][2] * invW
;
1057 uLeft
[u
] = u0
+ (span
.texStep
[u
][2] * adjx
+ dudy
[u
]
1058 * adjy
) * (1.0F
/FIXED_SCALE
);
1059 duOuter
[u
] = dudy
[u
] + dxOuter
* span
.texStep
[u
][2];
1060 v0
= vLower
->texcoord
[u
][3] * invW
;
1061 vLeft
[u
] = v0
+ (span
.texStep
[u
][3] * adjx
+ dvdy
[u
]
1062 * adjy
) * (1.0F
/FIXED_SCALE
);
1063 dvOuter
[u
] = dvdy
[u
] + dxOuter
* span
.texStep
[u
][3];
1072 if (setupRight
&& eRight
->lines
>0) {
1073 fxRightEdge
= eRight
->fsx
- FIXED_EPSILON
;
1074 fdxRightEdge
= eRight
->fdxdy
;
1082 /* Rasterize setup */
1083 #ifdef PIXEL_ADDRESS
1084 dPRowInner
= dPRowOuter
+ sizeof(PIXEL_TYPE
);
1088 dZRowInner
= dZRowOuter
+ sizeof(DEPTH_TYPE
);
1090 fdzInner
= fdzOuter
+ span
.zStep
;
1093 dfogInner
= dfogOuter
+ span
.fogStep
;
1095 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1096 fdrInner
= fdrOuter
+ span
.redStep
;
1097 fdgInner
= fdgOuter
+ span
.greenStep
;
1098 fdbInner
= fdbOuter
+ span
.blueStep
;
1100 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1101 fdaInner
= fdaOuter
+ span
.alphaStep
;
1103 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1104 fdsrInner
= fdsrOuter
+ span
.specRedStep
;
1105 fdsgInner
= fdsgOuter
+ span
.specGreenStep
;
1106 fdsbInner
= fdsbOuter
+ span
.specBlueStep
;
1109 fdiInner
= fdiOuter
+ span
.indexStep
;
1111 #ifdef INTERP_INT_TEX
1112 fdsInner
= fdsOuter
+ span
.intTexStep
[0];
1113 fdtInner
= fdtOuter
+ span
.intTexStep
[1];
1116 dsInner
= dsOuter
+ span
.texStep
[0][0];
1117 dtInner
= dtOuter
+ span
.texStep
[0][1];
1118 duInner
= duOuter
+ span
.texStep
[0][2];
1119 dvInner
= dvOuter
+ span
.texStep
[0][3];
1121 #ifdef INTERP_MULTITEX
1124 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1125 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1126 dsInner
[u
] = dsOuter
[u
] + span
.texStep
[u
][0];
1127 dtInner
[u
] = dtOuter
[u
] + span
.texStep
[u
][1];
1128 duInner
[u
] = duOuter
[u
] + span
.texStep
[u
][2];
1129 dvInner
[u
] = dvOuter
[u
] + span
.texStep
[u
][3];
1136 /* initialize the span interpolants to the leftmost value */
1137 /* ff = fixed-pt fragment */
1138 const GLint right
= FixedToInt(fxRightEdge
);
1139 span
.x
= FixedToInt(fxLeftEdge
);
1140 if (right
<= span
.x
)
1143 span
.count
= right
- span
.x
;
1151 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1156 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1159 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1161 span
.specGreen
= fsg
;
1162 span
.specBlue
= fsb
;
1167 #ifdef INTERP_INT_TEX
1168 span
.intTex
[0] = fs
;
1169 span
.intTex
[1] = ft
;
1173 span
.tex
[0][0] = sLeft
;
1174 span
.tex
[0][1] = tLeft
;
1175 span
.tex
[0][2] = uLeft
;
1176 span
.tex
[0][3] = vLeft
;
1179 #ifdef INTERP_MULTITEX
1182 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1183 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1184 span
.tex
[u
][0] = sLeft
[u
];
1185 span
.tex
[u
][1] = tLeft
[u
];
1186 span
.tex
[u
][2] = uLeft
[u
];
1187 span
.tex
[u
][3] = vLeft
[u
];
1195 /* need this to accomodate round-off errors */
1196 const GLint len
= right
- span
.x
- 1;
1197 GLfixed ffrend
= span
.red
+ len
* span
.redStep
;
1198 GLfixed ffgend
= span
.green
+ len
* span
.greenStep
;
1199 GLfixed ffbend
= span
.blue
+ len
* span
.blueStep
;
1206 span
.green
-= ffgend
;
1211 span
.blue
-= ffbend
;
1219 const GLint len
= right
- span
.x
- 1;
1220 GLfixed ffaend
= span
.alpha
+ len
* span
.alphaStep
;
1222 span
.alpha
-= ffaend
;
1230 /* need this to accomodate round-off errors */
1231 const GLint len
= right
- span
.x
- 1;
1232 GLfixed ffsrend
= span
.specRed
+ len
* span
.specRedStep
;
1233 GLfixed ffsgend
= span
.specGreen
+ len
* span
.specGreenStep
;
1234 GLfixed ffsbend
= span
.specBlue
+ len
* span
.specBlueStep
;
1236 span
.specRed
-= ffsrend
;
1237 if (span
.specRed
< 0)
1241 span
.specGreen
-= ffsgend
;
1242 if (span
.specGreen
< 0)
1246 span
.specBlue
-= ffsbend
;
1247 if (span
.specBlue
< 0)
1253 if (span
.index
< 0) span
.index
= 0;
1256 /* This is where we actually generate fragments */
1257 if (span
.count
> 0) {
1258 RENDER_SPAN( span
);
1262 * Advance to the next scan line. Compute the
1263 * new edge coordinates, and adjust the
1264 * pixel-center x coordinate so that it stays
1265 * on or inside the major edge.
1270 fxLeftEdge
+= fdxLeftEdge
;
1271 fxRightEdge
+= fdxRightEdge
;
1276 fError
-= FIXED_ONE
;
1277 #ifdef PIXEL_ADDRESS
1278 pRow
= (PIXEL_TYPE
*) ((GLubyte
*) pRow
+ dPRowOuter
);
1282 zRow
= (DEPTH_TYPE
*) ((GLubyte
*) zRow
+ dZRowOuter
);
1287 fogLeft
+= dfogOuter
;
1289 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1294 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1297 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1305 #ifdef INTERP_INT_TEX
1315 #ifdef INTERP_MULTITEX
1318 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1319 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1320 sLeft
[u
] += dsOuter
[u
];
1321 tLeft
[u
] += dtOuter
[u
];
1322 uLeft
[u
] += duOuter
[u
];
1323 vLeft
[u
] += dvOuter
[u
];
1330 #ifdef PIXEL_ADDRESS
1331 pRow
= (PIXEL_TYPE
*) ((GLubyte
*) pRow
+ dPRowInner
);
1335 zRow
= (DEPTH_TYPE
*) ((GLubyte
*) zRow
+ dZRowInner
);
1340 fogLeft
+= dfogInner
;
1342 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1347 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1350 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1358 #ifdef INTERP_INT_TEX
1368 #ifdef INTERP_MULTITEX
1371 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1372 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1373 sLeft
[u
] += dsInner
[u
];
1374 tLeft
[u
] += dtInner
[u
];
1375 uLeft
[u
] += duInner
[u
];
1376 vLeft
[u
] += dvInner
[u
];
1384 } /* for subTriangle */
1398 #undef BYTES_PER_ROW
1399 #undef PIXEL_ADDRESS
1407 #undef INTERP_INT_TEX
1409 #undef INTERP_MULTITEX
1410 #undef INTERP_LAMBDA
1411 #undef INTERP_FLOAT_RGBA
1412 #undef INTERP_FLOAT_SPEC
1419 #undef DO_OCCLUSION_TEST