1 /* $Id: s_tritemp.h,v 1.40 2002/10/17 15:26:39 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
/ (1 << SUB_PIXEL_BITS
)) - 1); /* for x/y coord snapping */
119 GLfixed vMin_fx
, vMin_fy
, vMid_fx
, vMid_fy
, vMax_fx
, vMax_fy
;
123 INIT_SPAN(span
, GL_POLYGON
, 0, 0, 0);
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 (IS_INF_OR_NAN(area
) || area
== 0.0F
)
212 oneOverArea
= 1.0F
/ area
;
215 #ifndef DO_OCCLUSION_TEST
216 ctx
->OcclusionResult
= GL_TRUE
;
218 span
.facing
= ctx
->_Facing
; /* for 2-sided stencil test */
220 /* Edge setup. For a triangle strip these could be reused... */
222 eMaj
.fsy
= FixedCeil(vMin_fy
);
223 eMaj
.lines
= FixedToInt(FixedCeil(vMax_fy
- eMaj
.fsy
));
224 if (eMaj
.lines
> 0) {
225 GLfloat dxdy
= eMaj
.dx
/ eMaj
.dy
;
226 eMaj
.fdxdy
= SignedFloatToFixed(dxdy
);
227 eMaj
.adjy
= (GLfloat
) (eMaj
.fsy
- vMin_fy
); /* SCALED! */
229 eMaj
.fsx
= eMaj
.fx0
+ (GLfixed
) (eMaj
.adjy
* dxdy
);
235 eTop
.fsy
= FixedCeil(vMid_fy
);
236 eTop
.lines
= FixedToInt(FixedCeil(vMax_fy
- eTop
.fsy
));
237 if (eTop
.lines
> 0) {
238 GLfloat dxdy
= eTop
.dx
/ eTop
.dy
;
239 eTop
.fdxdy
= SignedFloatToFixed(dxdy
);
240 eTop
.adjy
= (GLfloat
) (eTop
.fsy
- vMid_fy
); /* SCALED! */
242 eTop
.fsx
= eTop
.fx0
+ (GLfixed
) (eTop
.adjy
* dxdy
);
245 eBot
.fsy
= FixedCeil(vMin_fy
);
246 eBot
.lines
= FixedToInt(FixedCeil(vMid_fy
- eBot
.fsy
));
247 if (eBot
.lines
> 0) {
248 GLfloat dxdy
= eBot
.dx
/ eBot
.dy
;
249 eBot
.fdxdy
= SignedFloatToFixed(dxdy
);
250 eBot
.adjy
= (GLfloat
) (eBot
.fsy
- vMin_fy
); /* SCALED! */
252 eBot
.fsx
= eBot
.fx0
+ (GLfixed
) (eBot
.adjy
* dxdy
);
257 * Conceptually, we view a triangle as two subtriangles
258 * separated by a perfectly horizontal line. The edge that is
259 * intersected by this line is one with maximal absolute dy; we
260 * call it a ``major'' edge. The other two edges are the
261 * ``top'' edge (for the upper subtriangle) and the ``bottom''
262 * edge (for the lower subtriangle). If either of these two
263 * edges is horizontal or very close to horizontal, the
264 * corresponding subtriangle might cover zero sample points;
265 * we take care to handle such cases, for performance as well
268 * By stepping rasterization parameters along the major edge,
269 * we can avoid recomputing them at the discontinuity where
270 * the top and bottom edges meet. However, this forces us to
271 * be able to scan both left-to-right and right-to-left.
272 * Also, we must determine whether the major edge is at the
273 * left or right side of the triangle. We do this by
274 * computing the magnitude of the cross-product of the major
275 * and top edges. Since this magnitude depends on the sine of
276 * the angle between the two edges, its sign tells us whether
277 * we turn to the left or to the right when travelling along
278 * the major edge to the top edge, and from this we infer
279 * whether the major edge is on the left or the right.
281 * Serendipitously, this cross-product magnitude is also a
282 * value we need to compute the iteration parameter
283 * derivatives for the triangle, and it can be used to perform
284 * backface culling because its sign tells us whether the
285 * triangle is clockwise or counterclockwise. In this code we
286 * refer to it as ``area'' because it's also proportional to
287 * the pixel area of the triangle.
291 GLint scan_from_left_to_right
; /* true if scanning left-to-right */
298 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
303 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
306 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
307 GLfloat dsrdx
, dsrdy
;
308 GLfloat dsgdx
, dsgdy
;
309 GLfloat dsbdx
, dsbdy
;
314 #ifdef INTERP_INT_TEX
324 #ifdef INTERP_MULTITEX
325 GLfloat dsdx
[MAX_TEXTURE_UNITS
], dsdy
[MAX_TEXTURE_UNITS
];
326 GLfloat dtdx
[MAX_TEXTURE_UNITS
], dtdy
[MAX_TEXTURE_UNITS
];
327 GLfloat dudx
[MAX_TEXTURE_UNITS
], dudy
[MAX_TEXTURE_UNITS
];
328 GLfloat dvdx
[MAX_TEXTURE_UNITS
], dvdy
[MAX_TEXTURE_UNITS
];
332 * Execute user-supplied setup code
338 scan_from_left_to_right
= (oneOverArea
< 0.0F
);
341 /* compute d?/dx and d?/dy derivatives */
343 span
.interpMask
|= SPAN_Z
;
345 GLfloat eMaj_dz
, eBot_dz
;
346 eMaj_dz
= vMax
->win
[2] - vMin
->win
[2];
347 eBot_dz
= vMid
->win
[2] - vMin
->win
[2];
348 dzdx
= oneOverArea
* (eMaj_dz
* eBot
.dy
- eMaj
.dy
* eBot_dz
);
349 if (dzdx
> maxDepth
|| dzdx
< -maxDepth
) {
350 /* probably a sliver triangle */
355 dzdy
= oneOverArea
* (eMaj
.dx
* eBot_dz
- eMaj_dz
* eBot
.dx
);
358 span
.zStep
= SignedFloatToFixed(dzdx
);
360 span
.zStep
= (GLint
) dzdx
;
364 span
.interpMask
|= SPAN_FOG
;
366 const GLfloat eMaj_dfog
= vMax
->fog
- vMin
->fog
;
367 const GLfloat eBot_dfog
= vMid
->fog
- vMin
->fog
;
368 span
.fogStep
= oneOverArea
* (eMaj_dfog
* eBot
.dy
- eMaj
.dy
* eBot_dfog
);
369 dfogdy
= oneOverArea
* (eMaj
.dx
* eBot_dfog
- eMaj_dfog
* eBot
.dx
);
373 span
.interpMask
|= SPAN_RGBA
;
374 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
375 GLfloat eMaj_dr
, eBot_dr
;
376 GLfloat eMaj_dg
, eBot_dg
;
377 GLfloat eMaj_db
, eBot_db
;
379 GLfloat eMaj_da
, eBot_da
;
381 eMaj_dr
= (GLfloat
) ((GLint
) vMax
->color
[RCOMP
] -
382 (GLint
) vMin
->color
[RCOMP
]);
383 eBot_dr
= (GLfloat
) ((GLint
) vMid
->color
[RCOMP
] -
384 (GLint
) vMin
->color
[RCOMP
]);
385 drdx
= oneOverArea
* (eMaj_dr
* eBot
.dy
- eMaj
.dy
* eBot_dr
);
386 span
.redStep
= SignedFloatToFixed(drdx
);
387 drdy
= oneOverArea
* (eMaj
.dx
* eBot_dr
- eMaj_dr
* eBot
.dx
);
388 eMaj_dg
= (GLfloat
) ((GLint
) vMax
->color
[GCOMP
] -
389 (GLint
) vMin
->color
[GCOMP
]);
390 eBot_dg
= (GLfloat
) ((GLint
) vMid
->color
[GCOMP
] -
391 (GLint
) vMin
->color
[GCOMP
]);
392 dgdx
= oneOverArea
* (eMaj_dg
* eBot
.dy
- eMaj
.dy
* eBot_dg
);
393 span
.greenStep
= SignedFloatToFixed(dgdx
);
394 dgdy
= oneOverArea
* (eMaj
.dx
* eBot_dg
- eMaj_dg
* eBot
.dx
);
395 eMaj_db
= (GLfloat
) ((GLint
) vMax
->color
[BCOMP
] -
396 (GLint
) vMin
->color
[BCOMP
]);
397 eBot_db
= (GLfloat
) ((GLint
) vMid
->color
[BCOMP
] -
398 (GLint
) vMin
->color
[BCOMP
]);
399 dbdx
= oneOverArea
* (eMaj_db
* eBot
.dy
- eMaj
.dy
* eBot_db
);
400 span
.blueStep
= SignedFloatToFixed(dbdx
);
401 dbdy
= oneOverArea
* (eMaj
.dx
* eBot_db
- eMaj_db
* eBot
.dx
);
403 eMaj_da
= (GLfloat
) ((GLint
) vMax
->color
[ACOMP
] -
404 (GLint
) vMin
->color
[ACOMP
]);
405 eBot_da
= (GLfloat
) ((GLint
) vMid
->color
[ACOMP
] -
406 (GLint
) vMin
->color
[ACOMP
]);
407 dadx
= oneOverArea
* (eMaj_da
* eBot
.dy
- eMaj
.dy
* eBot_da
);
408 span
.alphaStep
= SignedFloatToFixed(dadx
);
409 dady
= oneOverArea
* (eMaj
.dx
* eBot_da
- eMaj_da
* eBot
.dx
);
413 ASSERT (ctx
->Light
.ShadeModel
== GL_FLAT
);
414 span
.interpMask
|= SPAN_FLAT
;
427 #ifdef INTERP_FLOAT_RGBA
428 span
.interpMask
|= SPAN_RGBA
;
429 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
430 GLfloat eMaj_dr
, eBot_dr
;
431 GLfloat eMaj_dg
, eBot_dg
;
432 GLfloat eMaj_db
, eBot_db
;
433 GLfloat eMaj_da
, eBot_da
;
434 eMaj_dr
= vMax
->color
[RCOMP
] - vMin
->color
[RCOMP
];
435 eBot_dr
= vMid
->color
[RCOMP
] - vMin
->color
[RCOMP
];
436 drdx
= oneOverArea
* (eMaj_dr
* eBot
.dy
- eMaj
.dy
* eBot_dr
);
438 drdy
= oneOverArea
* (eMaj
.dx
* eBot_dr
- eMaj_dr
* eBot
.dx
);
439 eMaj_dg
= vMax
->color
[GCOMP
] - vMin
->color
[GCOMP
];
440 eBot_dg
= vMid
->color
[GCOMP
] - vMin
->color
[GCOMP
];
441 dgdx
= oneOverArea
* (eMaj_dg
* eBot
.dy
- eMaj
.dy
* eBot_dg
);
442 span
.greenStep
= dgdx
;
443 dgdy
= oneOverArea
* (eMaj
.dx
* eBot_dg
- eMaj_dg
* eBot
.dx
);
444 eMaj_db
= vMax
->color
[BCOMP
] - vMin
->color
[BCOMP
];
445 eBot_db
= vMid
->color
[BCOMP
] - vMin
->color
[BCOMP
];
446 dbdx
= oneOverArea
* (eMaj_db
* eBot
.dy
- eMaj
.dy
* eBot_db
);
447 span
.blueStep
= dbdx
;
448 dbdy
= oneOverArea
* (eMaj
.dx
* eBot_db
- eMaj_db
* eBot
.dx
);
449 eMaj_da
= vMax
->color
[ACOMP
] - vMin
->color
[ACOMP
];
450 eBot_da
= vMid
->color
[ACOMP
] - vMin
->color
[ACOMP
];
451 dadx
= oneOverArea
* (eMaj_da
* eBot
.dy
- eMaj
.dy
* eBot_da
);
452 span
.alphaStep
= dadx
;
453 dady
= oneOverArea
* (eMaj
.dx
* eBot_da
- eMaj_da
* eBot
.dx
);
456 drdx
= drdy
= span
.redStep
= 0.0F
;
457 dgdx
= dgdy
= span
.greenStep
= 0.0F
;
458 dbdx
= dbdy
= span
.blueStep
= 0.0F
;
459 dadx
= dady
= span
.alphaStep
= 0.0F
;
463 span
.interpMask
|= SPAN_SPEC
;
464 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
465 GLfloat eMaj_dsr
, eBot_dsr
;
466 GLfloat eMaj_dsg
, eBot_dsg
;
467 GLfloat eMaj_dsb
, eBot_dsb
;
468 eMaj_dsr
= (GLfloat
) ((GLint
) vMax
->specular
[RCOMP
] -
469 (GLint
) vMin
->specular
[RCOMP
]);
470 eBot_dsr
= (GLfloat
) ((GLint
) vMid
->specular
[RCOMP
] -
471 (GLint
) vMin
->specular
[RCOMP
]);
472 dsrdx
= oneOverArea
* (eMaj_dsr
* eBot
.dy
- eMaj
.dy
* eBot_dsr
);
473 span
.specRedStep
= SignedFloatToFixed(dsrdx
);
474 dsrdy
= oneOverArea
* (eMaj
.dx
* eBot_dsr
- eMaj_dsr
* eBot
.dx
);
475 eMaj_dsg
= (GLfloat
) ((GLint
) vMax
->specular
[GCOMP
] -
476 (GLint
) vMin
->specular
[GCOMP
]);
477 eBot_dsg
= (GLfloat
) ((GLint
) vMid
->specular
[GCOMP
] -
478 (GLint
) vMin
->specular
[GCOMP
]);
479 dsgdx
= oneOverArea
* (eMaj_dsg
* eBot
.dy
- eMaj
.dy
* eBot_dsg
);
480 span
.specGreenStep
= SignedFloatToFixed(dsgdx
);
481 dsgdy
= oneOverArea
* (eMaj
.dx
* eBot_dsg
- eMaj_dsg
* eBot
.dx
);
482 eMaj_dsb
= (GLfloat
) ((GLint
) vMax
->specular
[BCOMP
] -
483 (GLint
) vMin
->specular
[BCOMP
]);
484 eBot_dsb
= (GLfloat
) ((GLint
) vMid
->specular
[BCOMP
] -
485 (GLint
) vMin
->specular
[BCOMP
]);
486 dsbdx
= oneOverArea
* (eMaj_dsb
* eBot
.dy
- eMaj
.dy
* eBot_dsb
);
487 span
.specBlueStep
= SignedFloatToFixed(dsbdx
);
488 dsbdy
= oneOverArea
* (eMaj
.dx
* eBot_dsb
- eMaj_dsb
* eBot
.dx
);
491 dsrdx
= dsrdy
= 0.0F
;
492 dsgdx
= dsgdy
= 0.0F
;
493 dsbdx
= dsbdy
= 0.0F
;
494 span
.specRedStep
= 0;
495 span
.specGreenStep
= 0;
496 span
.specBlueStep
= 0;
499 #ifdef INTERP_FLOAT_SPEC
500 span
.interpMask
|= SPAN_SPEC
;
501 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
502 GLfloat eMaj_dsr
, eBot_dsr
;
503 GLfloat eMaj_dsg
, eBot_dsg
;
504 GLfloat eMaj_dsb
, eBot_dsb
;
505 eMaj_dsr
= vMax
->specular
[RCOMP
] - vMin
->specular
[RCOMP
];
506 eBot_dsr
= vMid
->specular
[RCOMP
] - vMin
->specular
[RCOMP
];
507 dsrdx
= oneOverArea
* (eMaj_dsr
* eBot
.dy
- eMaj
.dy
* eBot_dsr
);
508 span
.specRedStep
= dsrdx
;
509 dsrdy
= oneOverArea
* (eMaj
.dx
* eBot_dsr
- eMaj_dsr
* eBot
.dx
);
510 eMaj_dsg
= vMax
->specular
[GCOMP
] - vMin
->specular
[GCOMP
];
511 eBot_dsg
= vMid
->specular
[GCOMP
] - vMin
->specular
[GCOMP
];
512 dsgdx
= oneOverArea
* (eMaj_dsg
* eBot
.dy
- eMaj
.dy
* eBot_dsg
);
513 span
.specGreenStep
= dsgdx
;
514 dsgdy
= oneOverArea
* (eMaj
.dx
* eBot_dsg
- eMaj_dsg
* eBot
.dx
);
515 eMaj_dsb
= vMax
->specular
[BCOMP
] - vMin
->specular
[BCOMP
];
516 eBot_dsb
= vMid
->specular
[BCOMP
] - vMin
->specular
[BCOMP
];
517 dsbdx
= oneOverArea
* (eMaj_dsb
* eBot
.dy
- eMaj
.dy
* eBot_dsb
);
518 span
.specBlueStep
= dsbdx
;
519 dsbdy
= oneOverArea
* (eMaj
.dx
* eBot_dsb
- eMaj_dsb
* eBot
.dx
);
522 dsrdx
= dsrdy
= span
.specRedStep
= 0;
523 dsgdx
= dsgdy
= span
.specGreenStep
= 0;
524 dsbdx
= dsbdy
= span
.specBlueStep
= 0;
528 span
.interpMask
|= SPAN_INDEX
;
529 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
530 GLfloat eMaj_di
, eBot_di
;
531 eMaj_di
= (GLfloat
) ((GLint
) vMax
->index
- (GLint
) vMin
->index
);
532 eBot_di
= (GLfloat
) ((GLint
) vMid
->index
- (GLint
) vMin
->index
);
533 didx
= oneOverArea
* (eMaj_di
* eBot
.dy
- eMaj
.dy
* eBot_di
);
534 span
.indexStep
= SignedFloatToFixed(didx
);
535 didy
= oneOverArea
* (eMaj
.dx
* eBot_di
- eMaj_di
* eBot
.dx
);
538 span
.interpMask
|= SPAN_FLAT
;
543 #ifdef INTERP_INT_TEX
544 span
.interpMask
|= SPAN_INT_TEXTURE
;
546 GLfloat eMaj_ds
, eBot_ds
;
547 eMaj_ds
= (vMax
->texcoord
[0][0] - vMin
->texcoord
[0][0]) * S_SCALE
;
548 eBot_ds
= (vMid
->texcoord
[0][0] - vMin
->texcoord
[0][0]) * S_SCALE
;
549 dsdx
= oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
550 span
.intTexStep
[0] = SignedFloatToFixed(dsdx
);
551 dsdy
= oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
554 GLfloat eMaj_dt
, eBot_dt
;
555 eMaj_dt
= (vMax
->texcoord
[0][1] - vMin
->texcoord
[0][1]) * T_SCALE
;
556 eBot_dt
= (vMid
->texcoord
[0][1] - vMin
->texcoord
[0][1]) * T_SCALE
;
557 dtdx
= oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
558 span
.intTexStep
[1] = SignedFloatToFixed(dtdx
);
559 dtdy
= oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
564 span
.interpMask
|= SPAN_TEXTURE
;
566 GLfloat wMax
= vMax
->win
[3];
567 GLfloat wMin
= vMin
->win
[3];
568 GLfloat wMid
= vMid
->win
[3];
569 GLfloat eMaj_ds
, eBot_ds
;
570 GLfloat eMaj_dt
, eBot_dt
;
571 GLfloat eMaj_du
, eBot_du
;
572 GLfloat eMaj_dv
, eBot_dv
;
574 eMaj_ds
= vMax
->texcoord
[0][0] * wMax
- vMin
->texcoord
[0][0] * wMin
;
575 eBot_ds
= vMid
->texcoord
[0][0] * wMid
- vMin
->texcoord
[0][0] * wMin
;
576 dsdx
= oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
577 dsdy
= oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
578 span
.texStepX
[0][0] = dsdx
;
579 span
.texStepY
[0][0] = dsdy
;
581 eMaj_dt
= vMax
->texcoord
[0][1] * wMax
- vMin
->texcoord
[0][1] * wMin
;
582 eBot_dt
= vMid
->texcoord
[0][1] * wMid
- vMin
->texcoord
[0][1] * wMin
;
583 dtdx
= oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
584 dtdy
= oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
585 span
.texStepX
[0][1] = dtdx
;
586 span
.texStepY
[0][1] = dtdy
;
588 eMaj_du
= vMax
->texcoord
[0][2] * wMax
- vMin
->texcoord
[0][2] * wMin
;
589 eBot_du
= vMid
->texcoord
[0][2] * wMid
- vMin
->texcoord
[0][2] * wMin
;
590 dudx
= oneOverArea
* (eMaj_du
* eBot
.dy
- eMaj
.dy
* eBot_du
);
591 dudy
= oneOverArea
* (eMaj
.dx
* eBot_du
- eMaj_du
* eBot
.dx
);
592 span
.texStepX
[0][2] = dudx
;
593 span
.texStepY
[0][2] = dudy
;
595 eMaj_dv
= vMax
->texcoord
[0][3] * wMax
- vMin
->texcoord
[0][3] * wMin
;
596 eBot_dv
= vMid
->texcoord
[0][3] * wMid
- vMin
->texcoord
[0][3] * wMin
;
597 dvdx
= oneOverArea
* (eMaj_dv
* eBot
.dy
- eMaj
.dy
* eBot_dv
);
598 dvdy
= oneOverArea
* (eMaj
.dx
* eBot_dv
- eMaj_dv
* eBot
.dx
);
599 span
.texStepX
[0][3] = dvdx
;
600 span
.texStepY
[0][3] = dvdy
;
603 #ifdef INTERP_MULTITEX
604 span
.interpMask
|= SPAN_TEXTURE
;
606 GLfloat wMax
= vMax
->win
[3];
607 GLfloat wMin
= vMin
->win
[3];
608 GLfloat wMid
= vMid
->win
[3];
610 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
611 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
612 GLfloat eMaj_ds
, eBot_ds
;
613 GLfloat eMaj_dt
, eBot_dt
;
614 GLfloat eMaj_du
, eBot_du
;
615 GLfloat eMaj_dv
, eBot_dv
;
616 eMaj_ds
= vMax
->texcoord
[u
][0] * wMax
617 - vMin
->texcoord
[u
][0] * wMin
;
618 eBot_ds
= vMid
->texcoord
[u
][0] * wMid
619 - vMin
->texcoord
[u
][0] * wMin
;
620 dsdx
[u
] = oneOverArea
* (eMaj_ds
* eBot
.dy
- eMaj
.dy
* eBot_ds
);
621 dsdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_ds
- eMaj_ds
* eBot
.dx
);
622 span
.texStepX
[u
][0] = dsdx
[u
];
623 span
.texStepY
[u
][0] = dsdy
[u
];
625 eMaj_dt
= vMax
->texcoord
[u
][1] * wMax
626 - vMin
->texcoord
[u
][1] * wMin
;
627 eBot_dt
= vMid
->texcoord
[u
][1] * wMid
628 - vMin
->texcoord
[u
][1] * wMin
;
629 dtdx
[u
] = oneOverArea
* (eMaj_dt
* eBot
.dy
- eMaj
.dy
* eBot_dt
);
630 dtdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_dt
- eMaj_dt
* eBot
.dx
);
631 span
.texStepX
[u
][1] = dtdx
[u
];
632 span
.texStepY
[u
][1] = dtdy
[u
];
634 eMaj_du
= vMax
->texcoord
[u
][2] * wMax
635 - vMin
->texcoord
[u
][2] * wMin
;
636 eBot_du
= vMid
->texcoord
[u
][2] * wMid
637 - vMin
->texcoord
[u
][2] * wMin
;
638 dudx
[u
] = oneOverArea
* (eMaj_du
* eBot
.dy
- eMaj
.dy
* eBot_du
);
639 dudy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_du
- eMaj_du
* eBot
.dx
);
640 span
.texStepX
[u
][2] = dudx
[u
];
641 span
.texStepY
[u
][2] = dudy
[u
];
643 eMaj_dv
= vMax
->texcoord
[u
][3] * wMax
644 - vMin
->texcoord
[u
][3] * wMin
;
645 eBot_dv
= vMid
->texcoord
[u
][3] * wMid
646 - vMin
->texcoord
[u
][3] * wMin
;
647 dvdx
[u
] = oneOverArea
* (eMaj_dv
* eBot
.dy
- eMaj
.dy
* eBot_dv
);
648 dvdy
[u
] = oneOverArea
* (eMaj
.dx
* eBot_dv
- eMaj_dv
* eBot
.dx
);
649 span
.texStepX
[u
][3] = dvdx
[u
];
650 span
.texStepY
[u
][3] = dvdy
[u
];
657 * We always sample at pixel centers. However, we avoid
658 * explicit half-pixel offsets in this code by incorporating
659 * the proper offset in each of x and y during the
660 * transformation to window coordinates.
662 * We also apply the usual rasterization rules to prevent
663 * cracks and overlaps. A pixel is considered inside a
664 * subtriangle if it meets all of four conditions: it is on or
665 * to the right of the left edge, strictly to the left of the
666 * right edge, on or below the top edge, and strictly above
667 * the bottom edge. (Some edges may be degenerate.)
669 * The following discussion assumes left-to-right scanning
670 * (that is, the major edge is on the left); the right-to-left
671 * case is a straightforward variation.
673 * We start by finding the half-integral y coordinate that is
674 * at or below the top of the triangle. This gives us the
675 * first scan line that could possibly contain pixels that are
676 * inside the triangle.
678 * Next we creep down the major edge until we reach that y,
679 * and compute the corresponding x coordinate on the edge.
680 * Then we find the half-integral x that lies on or just
681 * inside the edge. This is the first pixel that might lie in
682 * the interior of the triangle. (We won't know for sure
683 * until we check the other edges.)
685 * As we rasterize the triangle, we'll step down the major
686 * edge. For each step in y, we'll move an integer number
687 * of steps in x. There are two possible x step sizes, which
688 * we'll call the ``inner'' step (guaranteed to land on the
689 * edge or inside it) and the ``outer'' step (guaranteed to
690 * land on the edge or outside it). The inner and outer steps
691 * differ by one. During rasterization we maintain an error
692 * term that indicates our distance from the true edge, and
693 * select either the inner step or the outer step, whichever
694 * gets us to the first pixel that falls inside the triangle.
696 * All parameters (z, red, etc.) as well as the buffer
697 * addresses for color and z have inner and outer step values,
698 * so that we can increment them appropriately. This method
699 * eliminates the need to adjust parameters by creeping a
700 * sub-pixel amount into the triangle at each scanline.
706 GLfixed fxLeftEdge
= 0, fxRightEdge
= 0;
707 GLfixed fdxLeftEdge
= 0, fdxRightEdge
= 0;
711 GLfixed fError
= 0, fdError
= 0;
715 PIXEL_TYPE
*pRow
= NULL
;
716 int dPRowOuter
= 0, dPRowInner
; /* offset in bytes */
720 DEPTH_TYPE
*zRow
= NULL
;
721 int dZRowOuter
= 0, dZRowInner
; /* offset in bytes */
723 GLfixed fz
= 0, fdzOuter
= 0, fdzInner
;
726 GLfloat fogLeft
= 0, dfogOuter
= 0, dfogInner
;
729 GLfixed fr
= 0, fdrOuter
= 0, fdrInner
;
730 GLfixed fg
= 0, fdgOuter
= 0, fdgInner
;
731 GLfixed fb
= 0, fdbOuter
= 0, fdbInner
;
734 GLfixed fa
= 0, fdaOuter
= 0, fdaInner
;
736 #ifdef INTERP_FLOAT_RGBA
737 GLfloat fr
, fdrOuter
, fdrInner
;
738 GLfloat fg
, fdgOuter
, fdgInner
;
739 GLfloat fb
, fdbOuter
, fdbInner
;
740 GLfloat fa
, fdaOuter
, fdaInner
;
743 GLfixed fsr
=0, fdsrOuter
=0, fdsrInner
;
744 GLfixed fsg
=0, fdsgOuter
=0, fdsgInner
;
745 GLfixed fsb
=0, fdsbOuter
=0, fdsbInner
;
747 #ifdef INTERP_FLOAT_SPEC
748 GLfloat fsr
=0, fdsrOuter
=0, fdsrInner
;
749 GLfloat fsg
=0, fdsgOuter
=0, fdsgInner
;
750 GLfloat fsb
=0, fdsbOuter
=0, fdsbInner
;
753 GLfixed fi
=0, fdiOuter
=0, fdiInner
;
755 #ifdef INTERP_INT_TEX
756 GLfixed fs
=0, fdsOuter
=0, fdsInner
;
757 GLfixed ft
=0, fdtOuter
=0, fdtInner
;
760 GLfloat sLeft
=0, dsOuter
=0, dsInner
;
761 GLfloat tLeft
=0, dtOuter
=0, dtInner
;
762 GLfloat uLeft
=0, duOuter
=0, duInner
;
763 GLfloat vLeft
=0, dvOuter
=0, dvInner
;
765 #ifdef INTERP_MULTITEX
766 GLfloat sLeft
[MAX_TEXTURE_UNITS
];
767 GLfloat tLeft
[MAX_TEXTURE_UNITS
];
768 GLfloat uLeft
[MAX_TEXTURE_UNITS
];
769 GLfloat vLeft
[MAX_TEXTURE_UNITS
];
770 GLfloat dsOuter
[MAX_TEXTURE_UNITS
], dsInner
[MAX_TEXTURE_UNITS
];
771 GLfloat dtOuter
[MAX_TEXTURE_UNITS
], dtInner
[MAX_TEXTURE_UNITS
];
772 GLfloat duOuter
[MAX_TEXTURE_UNITS
], duInner
[MAX_TEXTURE_UNITS
];
773 GLfloat dvOuter
[MAX_TEXTURE_UNITS
], dvInner
[MAX_TEXTURE_UNITS
];
776 for (subTriangle
=0; subTriangle
<=1; subTriangle
++) {
777 EdgeT
*eLeft
, *eRight
;
778 int setupLeft
, setupRight
;
781 if (subTriangle
==0) {
783 if (scan_from_left_to_right
) {
786 lines
= eRight
->lines
;
793 lines
= eLeft
->lines
;
800 if (scan_from_left_to_right
) {
803 lines
= eRight
->lines
;
810 lines
= eLeft
->lines
;
818 if (setupLeft
&& eLeft
->lines
> 0) {
819 const SWvertex
*vLower
;
820 GLfixed fsx
= eLeft
->fsx
;
822 fError
= fx
- fsx
- FIXED_ONE
;
823 fxLeftEdge
= fsx
- FIXED_EPSILON
;
824 fdxLeftEdge
= eLeft
->fdxdy
;
825 fdxOuter
= FixedFloor(fdxLeftEdge
- FIXED_EPSILON
);
826 fdError
= fdxOuter
- fdxLeftEdge
+ FIXED_ONE
;
827 idxOuter
= FixedToInt(fdxOuter
);
828 dxOuter
= (float) idxOuter
;
832 span
.y
= FixedToInt(fy
);
834 adjx
= (float)(fx
- eLeft
->fx0
); /* SCALED! */
835 adjy
= eLeft
->adjy
; /* SCALED! */
836 (void) adjx
; /* silence compiler warnings */
837 (void) adjy
; /* silence compiler warnings */
840 (void) vLower
; /* silence compiler warnings */
844 pRow
= (PIXEL_TYPE
*) PIXEL_ADDRESS(FixedToInt(fxLeftEdge
), span
.y
);
845 dPRowOuter
= -((int)BYTES_PER_ROW
) + idxOuter
* sizeof(PIXEL_TYPE
);
846 /* negative because Y=0 at bottom and increases upward */
850 * Now we need the set of parameter (z, color, etc.) values at
851 * the point (fx, fy). This gives us properly-sampled parameter
852 * values that we can step from pixel to pixel. Furthermore,
853 * although we might have intermediate results that overflow
854 * the normal parameter range when we step temporarily outside
855 * the triangle, we shouldn't overflow or underflow for any
856 * pixel that's actually inside the triangle.
861 GLfloat z0
= vLower
->win
[2];
862 if (depthBits
<= 16) {
863 /* interpolate fixed-pt values */
864 GLfloat tmp
= (z0
* FIXED_SCALE
+
865 dzdx
* adjx
+ dzdy
* adjy
) + FIXED_HALF
;
866 if (tmp
< MAX_GLUINT
/ 2)
870 fdzOuter
= SignedFloatToFixed(dzdy
+ dxOuter
* dzdx
);
873 /* interpolate depth values exactly */
874 fz
= (GLint
) (z0
+ dzdx
* FixedToFloat(adjx
)
875 + dzdy
* FixedToFloat(adjy
));
876 fdzOuter
= (GLint
) (dzdy
+ dxOuter
* dzdx
);
879 zRow
= (DEPTH_TYPE
*)
880 _mesa_zbuffer_address(ctx
, FixedToInt(fxLeftEdge
), span
.y
);
881 dZRowOuter
= (ctx
->DrawBuffer
->Width
+ idxOuter
) * sizeof(DEPTH_TYPE
);
886 fogLeft
= vLower
->fog
+ (span
.fogStep
* adjx
+ dfogdy
* adjy
)
887 * (1.0F
/FIXED_SCALE
);
888 dfogOuter
= dfogdy
+ dxOuter
* span
.fogStep
;
891 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
892 fr
= (GLfixed
) (ChanToFixed(vLower
->color
[RCOMP
])
893 + drdx
* adjx
+ drdy
* adjy
) + FIXED_HALF
;
894 fdrOuter
= SignedFloatToFixed(drdy
+ dxOuter
* drdx
);
895 fg
= (GLfixed
) (ChanToFixed(vLower
->color
[GCOMP
])
896 + dgdx
* adjx
+ dgdy
* adjy
) + FIXED_HALF
;
897 fdgOuter
= SignedFloatToFixed(dgdy
+ dxOuter
* dgdx
);
898 fb
= (GLfixed
) (ChanToFixed(vLower
->color
[BCOMP
])
899 + dbdx
* adjx
+ dbdy
* adjy
) + FIXED_HALF
;
900 fdbOuter
= SignedFloatToFixed(dbdy
+ dxOuter
* dbdx
);
902 fa
= (GLfixed
) (ChanToFixed(vLower
->color
[ACOMP
])
903 + dadx
* adjx
+ dady
* adjy
) + FIXED_HALF
;
904 fdaOuter
= SignedFloatToFixed(dady
+ dxOuter
* dadx
);
908 ASSERT (ctx
->Light
.ShadeModel
== GL_FLAT
);
909 fr
= ChanToFixed(v2
->color
[RCOMP
]);
910 fg
= ChanToFixed(v2
->color
[GCOMP
]);
911 fb
= ChanToFixed(v2
->color
[BCOMP
]);
912 fdrOuter
= fdgOuter
= fdbOuter
= 0;
914 fa
= ChanToFixed(v2
->color
[ACOMP
]);
919 #ifdef INTERP_FLOAT_RGBA
920 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
921 fr
= vLower
->color
[RCOMP
]
922 + (drdx
* adjx
+ drdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
923 fdrOuter
= drdy
+ dxOuter
* drdx
;
924 fg
= vLower
->color
[GCOMP
]
925 + (dgdx
* adjx
+ dgdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
926 fdgOuter
= dgdy
+ dxOuter
* dgdx
;
927 fb
= vLower
->color
[BCOMP
]
928 + (dbdx
* adjx
+ dbdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
929 fdbOuter
= dbdy
+ dxOuter
* dbdx
;
930 fa
= vLower
->color
[ACOMP
]
931 + (dadx
* adjx
+ dady
* adjy
) * (1.0F
/ FIXED_SCALE
);
932 fdaOuter
= dady
+ dxOuter
* dadx
;
935 fr
= v2
->color
[RCOMP
];
936 fg
= v2
->color
[GCOMP
];
937 fb
= v2
->color
[BCOMP
];
938 fa
= v2
->color
[ACOMP
];
939 fdrOuter
= fdgOuter
= fdbOuter
= fdaOuter
= 0.0F
;
943 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
944 fsr
= (GLfixed
) (ChanToFixed(vLower
->specular
[RCOMP
])
945 + dsrdx
* adjx
+ dsrdy
* adjy
) + FIXED_HALF
;
946 fdsrOuter
= SignedFloatToFixed(dsrdy
+ dxOuter
* dsrdx
);
947 fsg
= (GLfixed
) (ChanToFixed(vLower
->specular
[GCOMP
])
948 + dsgdx
* adjx
+ dsgdy
* adjy
) + FIXED_HALF
;
949 fdsgOuter
= SignedFloatToFixed(dsgdy
+ dxOuter
* dsgdx
);
950 fsb
= (GLfixed
) (ChanToFixed(vLower
->specular
[BCOMP
])
951 + dsbdx
* adjx
+ dsbdy
* adjy
) + FIXED_HALF
;
952 fdsbOuter
= SignedFloatToFixed(dsbdy
+ dxOuter
* dsbdx
);
955 fsr
= ChanToFixed(v2
->specular
[RCOMP
]);
956 fsg
= ChanToFixed(v2
->specular
[GCOMP
]);
957 fsb
= ChanToFixed(v2
->specular
[BCOMP
]);
958 fdsrOuter
= fdsgOuter
= fdsbOuter
= 0;
961 #ifdef INTERP_FLOAT_SPEC
962 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
963 fsr
= vLower
->specular
[RCOMP
]
964 + (dsrdx
* adjx
+ dsrdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
965 fdsrOuter
= dsrdy
+ dxOuter
* dsrdx
;
966 fsg
= vLower
->specular
[GCOMP
]
967 + (dsgdx
* adjx
+ dsgdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
968 fdsgOuter
= dsgdy
+ dxOuter
* dsgdx
;
969 fsb
= vLower
->specular
[BCOMP
]
970 + (dsbdx
* adjx
+ dsbdy
* adjy
) * (1.0F
/ FIXED_SCALE
);
971 fdsbOuter
= dsbdy
+ dxOuter
* dsbdx
;
974 fsr
= v2
->specular
[RCOMP
];
975 fsg
= v2
->specular
[GCOMP
];
976 fsb
= v2
->specular
[BCOMP
];
977 fdsrOuter
= fdsgOuter
= fdsbOuter
= 0.0F
;
981 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
982 fi
= (GLfixed
)(vLower
->index
* FIXED_SCALE
983 + didx
* adjx
+ didy
* adjy
) + FIXED_HALF
;
984 fdiOuter
= SignedFloatToFixed(didy
+ dxOuter
* didx
);
987 fi
= (GLfixed
) (v2
->index
* FIXED_SCALE
);
991 #ifdef INTERP_INT_TEX
994 s0
= vLower
->texcoord
[0][0] * S_SCALE
;
995 fs
= (GLfixed
)(s0
* FIXED_SCALE
+ dsdx
* adjx
996 + dsdy
* adjy
) + FIXED_HALF
;
997 fdsOuter
= SignedFloatToFixed(dsdy
+ dxOuter
* dsdx
);
999 t0
= vLower
->texcoord
[0][1] * T_SCALE
;
1000 ft
= (GLfixed
)(t0
* FIXED_SCALE
+ dtdx
* adjx
1001 + dtdy
* adjy
) + FIXED_HALF
;
1002 fdtOuter
= SignedFloatToFixed(dtdy
+ dxOuter
* dtdx
);
1007 GLfloat invW
= vLower
->win
[3];
1008 GLfloat s0
, t0
, u0
, v0
;
1009 s0
= vLower
->texcoord
[0][0] * invW
;
1010 sLeft
= s0
+ (span
.texStepX
[0][0] * adjx
+ dsdy
* adjy
)
1011 * (1.0F
/FIXED_SCALE
);
1012 dsOuter
= dsdy
+ dxOuter
* span
.texStepX
[0][0];
1013 t0
= vLower
->texcoord
[0][1] * invW
;
1014 tLeft
= t0
+ (span
.texStepX
[0][1] * adjx
+ dtdy
* adjy
)
1015 * (1.0F
/FIXED_SCALE
);
1016 dtOuter
= dtdy
+ dxOuter
* span
.texStepX
[0][1];
1017 u0
= vLower
->texcoord
[0][2] * invW
;
1018 uLeft
= u0
+ (span
.texStepX
[0][2] * adjx
+ dudy
* adjy
)
1019 * (1.0F
/FIXED_SCALE
);
1020 duOuter
= dudy
+ dxOuter
* span
.texStepX
[0][2];
1021 v0
= vLower
->texcoord
[0][3] * invW
;
1022 vLeft
= v0
+ (span
.texStepX
[0][3] * adjx
+ dvdy
* adjy
)
1023 * (1.0F
/FIXED_SCALE
);
1024 dvOuter
= dvdy
+ dxOuter
* span
.texStepX
[0][3];
1027 #ifdef INTERP_MULTITEX
1030 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1031 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1032 GLfloat invW
= vLower
->win
[3];
1033 GLfloat s0
, t0
, u0
, v0
;
1034 s0
= vLower
->texcoord
[u
][0] * invW
;
1035 sLeft
[u
] = s0
+ (span
.texStepX
[u
][0] * adjx
+ dsdy
[u
]
1036 * adjy
) * (1.0F
/FIXED_SCALE
);
1037 dsOuter
[u
] = dsdy
[u
] + dxOuter
* span
.texStepX
[u
][0];
1038 t0
= vLower
->texcoord
[u
][1] * invW
;
1039 tLeft
[u
] = t0
+ (span
.texStepX
[u
][1] * adjx
+ dtdy
[u
]
1040 * adjy
) * (1.0F
/FIXED_SCALE
);
1041 dtOuter
[u
] = dtdy
[u
] + dxOuter
* span
.texStepX
[u
][1];
1042 u0
= vLower
->texcoord
[u
][2] * invW
;
1043 uLeft
[u
] = u0
+ (span
.texStepX
[u
][2] * adjx
+ dudy
[u
]
1044 * adjy
) * (1.0F
/FIXED_SCALE
);
1045 duOuter
[u
] = dudy
[u
] + dxOuter
* span
.texStepX
[u
][2];
1046 v0
= vLower
->texcoord
[u
][3] * invW
;
1047 vLeft
[u
] = v0
+ (span
.texStepX
[u
][3] * adjx
+ dvdy
[u
]
1048 * adjy
) * (1.0F
/FIXED_SCALE
);
1049 dvOuter
[u
] = dvdy
[u
] + dxOuter
* span
.texStepX
[u
][3];
1058 if (setupRight
&& eRight
->lines
>0) {
1059 fxRightEdge
= eRight
->fsx
- FIXED_EPSILON
;
1060 fdxRightEdge
= eRight
->fdxdy
;
1068 /* Rasterize setup */
1069 #ifdef PIXEL_ADDRESS
1070 dPRowInner
= dPRowOuter
+ sizeof(PIXEL_TYPE
);
1074 dZRowInner
= dZRowOuter
+ sizeof(DEPTH_TYPE
);
1076 fdzInner
= fdzOuter
+ span
.zStep
;
1079 dfogInner
= dfogOuter
+ span
.fogStep
;
1081 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1082 fdrInner
= fdrOuter
+ span
.redStep
;
1083 fdgInner
= fdgOuter
+ span
.greenStep
;
1084 fdbInner
= fdbOuter
+ span
.blueStep
;
1086 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1087 fdaInner
= fdaOuter
+ span
.alphaStep
;
1089 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1090 fdsrInner
= fdsrOuter
+ span
.specRedStep
;
1091 fdsgInner
= fdsgOuter
+ span
.specGreenStep
;
1092 fdsbInner
= fdsbOuter
+ span
.specBlueStep
;
1095 fdiInner
= fdiOuter
+ span
.indexStep
;
1097 #ifdef INTERP_INT_TEX
1098 fdsInner
= fdsOuter
+ span
.intTexStep
[0];
1099 fdtInner
= fdtOuter
+ span
.intTexStep
[1];
1102 dsInner
= dsOuter
+ span
.texStepX
[0][0];
1103 dtInner
= dtOuter
+ span
.texStepX
[0][1];
1104 duInner
= duOuter
+ span
.texStepX
[0][2];
1105 dvInner
= dvOuter
+ span
.texStepX
[0][3];
1107 #ifdef INTERP_MULTITEX
1110 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1111 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1112 dsInner
[u
] = dsOuter
[u
] + span
.texStepX
[u
][0];
1113 dtInner
[u
] = dtOuter
[u
] + span
.texStepX
[u
][1];
1114 duInner
[u
] = duOuter
[u
] + span
.texStepX
[u
][2];
1115 dvInner
[u
] = dvOuter
[u
] + span
.texStepX
[u
][3];
1122 /* initialize the span interpolants to the leftmost value */
1123 /* ff = fixed-pt fragment */
1124 const GLint right
= FixedToInt(fxRightEdge
);
1126 span
.x
= FixedToInt(fxLeftEdge
);
1128 if (right
<= span
.x
)
1131 span
.end
= right
- span
.x
;
1139 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1144 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1147 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1149 span
.specGreen
= fsg
;
1150 span
.specBlue
= fsb
;
1155 #ifdef INTERP_INT_TEX
1156 span
.intTex
[0] = fs
;
1157 span
.intTex
[1] = ft
;
1161 span
.tex
[0][0] = sLeft
;
1162 span
.tex
[0][1] = tLeft
;
1163 span
.tex
[0][2] = uLeft
;
1164 span
.tex
[0][3] = vLeft
;
1167 #ifdef INTERP_MULTITEX
1170 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1171 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1172 span
.tex
[u
][0] = sLeft
[u
];
1173 span
.tex
[u
][1] = tLeft
[u
];
1174 span
.tex
[u
][2] = uLeft
[u
];
1175 span
.tex
[u
][3] = vLeft
[u
];
1183 /* need this to accomodate round-off errors */
1184 const GLint len
= right
- span
.x
- 1;
1185 GLfixed ffrend
= span
.red
+ len
* span
.redStep
;
1186 GLfixed ffgend
= span
.green
+ len
* span
.greenStep
;
1187 GLfixed ffbend
= span
.blue
+ len
* span
.blueStep
;
1194 span
.green
-= ffgend
;
1199 span
.blue
-= ffbend
;
1207 const GLint len
= right
- span
.x
- 1;
1208 GLfixed ffaend
= span
.alpha
+ len
* span
.alphaStep
;
1210 span
.alpha
-= ffaend
;
1218 /* need this to accomodate round-off errors */
1219 const GLint len
= right
- span
.x
- 1;
1220 GLfixed ffsrend
= span
.specRed
+ len
* span
.specRedStep
;
1221 GLfixed ffsgend
= span
.specGreen
+ len
* span
.specGreenStep
;
1222 GLfixed ffsbend
= span
.specBlue
+ len
* span
.specBlueStep
;
1224 span
.specRed
-= ffsrend
;
1225 if (span
.specRed
< 0)
1229 span
.specGreen
-= ffsgend
;
1230 if (span
.specGreen
< 0)
1234 span
.specBlue
-= ffsbend
;
1235 if (span
.specBlue
< 0)
1241 if (span
.index
< 0) span
.index
= 0;
1244 /* This is where we actually generate fragments */
1246 RENDER_SPAN( span
);
1250 * Advance to the next scan line. Compute the
1251 * new edge coordinates, and adjust the
1252 * pixel-center x coordinate so that it stays
1253 * on or inside the major edge.
1258 fxLeftEdge
+= fdxLeftEdge
;
1259 fxRightEdge
+= fdxRightEdge
;
1264 fError
-= FIXED_ONE
;
1265 #ifdef PIXEL_ADDRESS
1266 pRow
= (PIXEL_TYPE
*) ((GLubyte
*) pRow
+ dPRowOuter
);
1270 zRow
= (DEPTH_TYPE
*) ((GLubyte
*) zRow
+ dZRowOuter
);
1275 fogLeft
+= dfogOuter
;
1277 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1282 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1285 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1293 #ifdef INTERP_INT_TEX
1303 #ifdef INTERP_MULTITEX
1306 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1307 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1308 sLeft
[u
] += dsOuter
[u
];
1309 tLeft
[u
] += dtOuter
[u
];
1310 uLeft
[u
] += duOuter
[u
];
1311 vLeft
[u
] += dvOuter
[u
];
1318 #ifdef PIXEL_ADDRESS
1319 pRow
= (PIXEL_TYPE
*) ((GLubyte
*) pRow
+ dPRowInner
);
1323 zRow
= (DEPTH_TYPE
*) ((GLubyte
*) zRow
+ dZRowInner
);
1328 fogLeft
+= dfogInner
;
1330 #if defined(INTERP_RGB) || defined(INTERP_FLOAT_RGBA)
1335 #if defined(INTERP_ALPHA) || defined(INTERP_FLOAT_RGBA)
1338 #if defined(INTERP_SPEC) || defined(INTERP_FLOAT_SPEC)
1346 #ifdef INTERP_INT_TEX
1356 #ifdef INTERP_MULTITEX
1359 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
1360 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
1361 sLeft
[u
] += dsInner
[u
];
1362 tLeft
[u
] += dtInner
[u
];
1363 uLeft
[u
] += duInner
[u
];
1364 vLeft
[u
] += dvInner
[u
];
1372 } /* for subTriangle */
1386 #undef BYTES_PER_ROW
1387 #undef PIXEL_ADDRESS
1395 #undef INTERP_INT_TEX
1397 #undef INTERP_MULTITEX
1398 #undef INTERP_FLOAT_RGBA
1399 #undef INTERP_FLOAT_SPEC
1406 #undef DO_OCCLUSION_TEST