1 /* $Id: s_aatritemp.h,v 1.30 2002/08/07 00:45:07 brianp Exp $ */
4 * Mesa 3-D graphics library
7 * Copyright (C) 1999-2002 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 * Antialiased Triangle Rasterizer Template
31 * This file is #include'd to generate custom AA triangle rasterizers.
32 * NOTE: this code hasn't been optimized yet. That'll come after it
35 * The following macros may be defined to indicate what auxillary information
36 * must be copmuted across the triangle:
37 * DO_Z - if defined, compute Z values
38 * DO_RGBA - if defined, compute RGBA values
39 * DO_INDEX - if defined, compute color index values
40 * DO_SPEC - if defined, compute specular RGB values
41 * DO_TEX - if defined, compute unit 0 STRQ texcoords
42 * DO_MULTITEX - if defined, compute all unit's STRQ texcoords
45 /*void triangle( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint pv )*/
47 const GLfloat
*p0
= v0
->win
;
48 const GLfloat
*p1
= v1
->win
;
49 const GLfloat
*p2
= v2
->win
;
50 const SWvertex
*vMin
, *vMid
, *vMax
;
54 GLfloat majDx
, majDy
; /* major (i.e. long) edge dx and dy */
67 GLfloat rPlane
[4], gPlane
[4], bPlane
[4], aPlane
[4];
73 GLfloat srPlane
[4], sgPlane
[4], sbPlane
[4];
76 GLfloat sPlane
[4], tPlane
[4], uPlane
[4], vPlane
[4];
77 GLfloat texWidth
, texHeight
;
78 #elif defined(DO_MULTITEX)
79 GLfloat sPlane
[MAX_TEXTURE_UNITS
][4]; /* texture S */
80 GLfloat tPlane
[MAX_TEXTURE_UNITS
][4]; /* texture T */
81 GLfloat uPlane
[MAX_TEXTURE_UNITS
][4]; /* texture R */
82 GLfloat vPlane
[MAX_TEXTURE_UNITS
][4]; /* texture Q */
83 GLfloat texWidth
[MAX_TEXTURE_UNITS
], texHeight
[MAX_TEXTURE_UNITS
];
85 GLfloat bf
= SWRAST_CONTEXT(ctx
)->_backface_sign
;
88 INIT_SPAN(span
, GL_POLYGON
, 0, 0, SPAN_COVERAGE
);
90 /* determine bottom to top order of vertices */
92 GLfloat y0
= v0
->win
[1];
93 GLfloat y1
= v1
->win
[1];
94 GLfloat y2
= v2
->win
[1];
97 vMin
= v0
; vMid
= v1
; vMax
= v2
; /* y0<=y1<=y2 */
100 vMin
= v2
; vMid
= v0
; vMax
= v1
; /* y2<=y0<=y1 */
103 vMin
= v0
; vMid
= v2
; vMax
= v1
; bf
= -bf
; /* y0<=y2<=y1 */
108 vMin
= v1
; vMid
= v0
; vMax
= v2
; bf
= -bf
; /* y1<=y0<=y2 */
111 vMin
= v2
; vMid
= v1
; vMax
= v0
; bf
= -bf
; /* y2<=y1<=y0 */
114 vMin
= v1
; vMid
= v2
; vMax
= v0
; /* y1<=y2<=y0 */
119 majDx
= vMax
->win
[0] - vMin
->win
[0];
120 majDy
= vMax
->win
[1] - vMin
->win
[1];
123 const GLfloat botDx
= vMid
->win
[0] - vMin
->win
[0];
124 const GLfloat botDy
= vMid
->win
[1] - vMin
->win
[1];
125 const GLfloat area
= majDx
* botDy
- botDx
* majDy
;
126 ltor
= (GLboolean
) (area
< 0.0F
);
127 /* Do backface culling */
128 if (area
* bf
< 0 || area
== 0 || IS_INF_OR_NAN(area
))
132 #ifndef DO_OCCLUSION_TEST
133 ctx
->OcclusionResult
= GL_TRUE
;
136 /* Plane equation setup:
137 * We evaluate plane equations at window (x,y) coordinates in order
138 * to compute color, Z, fog, texcoords, etc. This isn't terribly
139 * efficient but it's easy and reliable.
142 compute_plane(p0
, p1
, p2
, p0
[2], p1
[2], p2
[2], zPlane
);
143 span
.arrayMask
|= SPAN_Z
;
146 compute_plane(p0
, p1
, p2
, v0
->fog
, v1
->fog
, v2
->fog
, fogPlane
);
147 span
.arrayMask
|= SPAN_FOG
;
150 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
151 compute_plane(p0
, p1
, p2
, v0
->color
[0], v1
->color
[0], v2
->color
[0], rPlane
);
152 compute_plane(p0
, p1
, p2
, v0
->color
[1], v1
->color
[1], v2
->color
[1], gPlane
);
153 compute_plane(p0
, p1
, p2
, v0
->color
[2], v1
->color
[2], v2
->color
[2], bPlane
);
154 compute_plane(p0
, p1
, p2
, v0
->color
[3], v1
->color
[3], v2
->color
[3], aPlane
);
157 constant_plane(v2
->color
[RCOMP
], rPlane
);
158 constant_plane(v2
->color
[GCOMP
], gPlane
);
159 constant_plane(v2
->color
[BCOMP
], bPlane
);
160 constant_plane(v2
->color
[ACOMP
], aPlane
);
162 span
.arrayMask
|= SPAN_RGBA
;
165 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
166 compute_plane(p0
, p1
, p2
, (GLfloat
) v0
->index
,
167 (GLfloat
) v1
->index
, (GLfloat
) v2
->index
, iPlane
);
170 constant_plane((GLfloat
) v2
->index
, iPlane
);
172 span
.arrayMask
|= SPAN_INDEX
;
175 if (ctx
->Light
.ShadeModel
== GL_SMOOTH
) {
176 compute_plane(p0
, p1
, p2
, v0
->specular
[0], v1
->specular
[0], v2
->specular
[0],srPlane
);
177 compute_plane(p0
, p1
, p2
, v0
->specular
[1], v1
->specular
[1], v2
->specular
[1],sgPlane
);
178 compute_plane(p0
, p1
, p2
, v0
->specular
[2], v1
->specular
[2], v2
->specular
[2],sbPlane
);
181 constant_plane(v2
->specular
[RCOMP
], srPlane
);
182 constant_plane(v2
->specular
[GCOMP
], sgPlane
);
183 constant_plane(v2
->specular
[BCOMP
], sbPlane
);
185 span
.arrayMask
|= SPAN_SPEC
;
189 const struct gl_texture_object
*obj
= ctx
->Texture
.Unit
[0]._Current
;
190 const struct gl_texture_image
*texImage
= obj
->Image
[obj
->BaseLevel
];
191 const GLfloat invW0
= v0
->win
[3];
192 const GLfloat invW1
= v1
->win
[3];
193 const GLfloat invW2
= v2
->win
[3];
194 const GLfloat s0
= v0
->texcoord
[0][0] * invW0
;
195 const GLfloat s1
= v1
->texcoord
[0][0] * invW1
;
196 const GLfloat s2
= v2
->texcoord
[0][0] * invW2
;
197 const GLfloat t0
= v0
->texcoord
[0][1] * invW0
;
198 const GLfloat t1
= v1
->texcoord
[0][1] * invW1
;
199 const GLfloat t2
= v2
->texcoord
[0][1] * invW2
;
200 const GLfloat r0
= v0
->texcoord
[0][2] * invW0
;
201 const GLfloat r1
= v1
->texcoord
[0][2] * invW1
;
202 const GLfloat r2
= v2
->texcoord
[0][2] * invW2
;
203 const GLfloat q0
= v0
->texcoord
[0][3] * invW0
;
204 const GLfloat q1
= v1
->texcoord
[0][3] * invW1
;
205 const GLfloat q2
= v2
->texcoord
[0][3] * invW2
;
206 compute_plane(p0
, p1
, p2
, s0
, s1
, s2
, sPlane
);
207 compute_plane(p0
, p1
, p2
, t0
, t1
, t2
, tPlane
);
208 compute_plane(p0
, p1
, p2
, r0
, r1
, r2
, uPlane
);
209 compute_plane(p0
, p1
, p2
, q0
, q1
, q2
, vPlane
);
210 texWidth
= (GLfloat
) texImage
->Width
;
211 texHeight
= (GLfloat
) texImage
->Height
;
213 span
.arrayMask
|= (SPAN_TEXTURE
| SPAN_LAMBDA
);
214 #elif defined(DO_MULTITEX)
217 for (u
= 0; u
< ctx
->Const
.MaxTextureUnits
; u
++) {
218 if (ctx
->Texture
.Unit
[u
]._ReallyEnabled
) {
219 const struct gl_texture_object
*obj
= ctx
->Texture
.Unit
[u
]._Current
;
220 const struct gl_texture_image
*texImage
= obj
->Image
[obj
->BaseLevel
];
221 const GLfloat invW0
= v0
->win
[3];
222 const GLfloat invW1
= v1
->win
[3];
223 const GLfloat invW2
= v2
->win
[3];
224 const GLfloat s0
= v0
->texcoord
[u
][0] * invW0
;
225 const GLfloat s1
= v1
->texcoord
[u
][0] * invW1
;
226 const GLfloat s2
= v2
->texcoord
[u
][0] * invW2
;
227 const GLfloat t0
= v0
->texcoord
[u
][1] * invW0
;
228 const GLfloat t1
= v1
->texcoord
[u
][1] * invW1
;
229 const GLfloat t2
= v2
->texcoord
[u
][1] * invW2
;
230 const GLfloat r0
= v0
->texcoord
[u
][2] * invW0
;
231 const GLfloat r1
= v1
->texcoord
[u
][2] * invW1
;
232 const GLfloat r2
= v2
->texcoord
[u
][2] * invW2
;
233 const GLfloat q0
= v0
->texcoord
[u
][3] * invW0
;
234 const GLfloat q1
= v1
->texcoord
[u
][3] * invW1
;
235 const GLfloat q2
= v2
->texcoord
[u
][3] * invW2
;
236 compute_plane(p0
, p1
, p2
, s0
, s1
, s2
, sPlane
[u
]);
237 compute_plane(p0
, p1
, p2
, t0
, t1
, t2
, tPlane
[u
]);
238 compute_plane(p0
, p1
, p2
, r0
, r1
, r2
, uPlane
[u
]);
239 compute_plane(p0
, p1
, p2
, q0
, q1
, q2
, vPlane
[u
]);
240 texWidth
[u
] = (GLfloat
) texImage
->Width
;
241 texHeight
[u
] = (GLfloat
) texImage
->Height
;
245 span
.arrayMask
|= (SPAN_TEXTURE
| SPAN_LAMBDA
);
248 /* Begin bottom-to-top scan over the triangle.
249 * The long edge will either be on the left or right side of the
250 * triangle. We always scan from the long edge toward the shorter
251 * edges, stopping when we find that coverage = 0. If the long edge
252 * is on the left we scan left-to-right. Else, we scan right-to-left.
256 iyMin
= (GLint
) yMin
;
257 iyMax
= (GLint
) yMax
+ 1;
260 /* scan left to right */
261 const GLfloat
*pMin
= vMin
->win
;
262 const GLfloat
*pMid
= vMid
->win
;
263 const GLfloat
*pMax
= vMax
->win
;
264 const GLfloat dxdy
= majDx
/ majDy
;
265 const GLfloat xAdj
= dxdy
< 0.0F
? -dxdy
: 0.0F
;
266 GLfloat x
= pMin
[0] - (yMin
- iyMin
) * dxdy
;
268 for (iy
= iyMin
; iy
< iyMax
; iy
++, x
+= dxdy
) {
269 GLint ix
, startX
= (GLint
) (x
- xAdj
);
271 GLfloat coverage
= 0.0F
;
273 /* skip over fragments with zero coverage */
274 while (startX
< MAX_WIDTH
) {
275 coverage
= compute_coveragef(pMin
, pMid
, pMax
, startX
, iy
);
281 /* enter interior of triangle */
284 while (coverage
> 0.0F
) {
285 /* (cx,cy) = center of fragment */
286 const GLfloat cx
= ix
+ 0.5F
, cy
= iy
+ 0.5F
;
287 struct span_arrays
*array
= span
.array
;
289 array
->coverage
[count
] = (GLfloat
) compute_coveragei(pMin
, pMid
, pMax
, ix
, iy
);
291 array
->coverage
[count
] = coverage
;
294 array
->z
[count
] = (GLdepth
) solve_plane(cx
, cy
, zPlane
);
297 array
->fog
[count
] = solve_plane(cx
, cy
, fogPlane
);
300 array
->rgba
[count
][RCOMP
] = solve_plane_chan(cx
, cy
, rPlane
);
301 array
->rgba
[count
][GCOMP
] = solve_plane_chan(cx
, cy
, gPlane
);
302 array
->rgba
[count
][BCOMP
] = solve_plane_chan(cx
, cy
, bPlane
);
303 array
->rgba
[count
][ACOMP
] = solve_plane_chan(cx
, cy
, aPlane
);
306 array
->index
[count
] = (GLint
) solve_plane(cx
, cy
, iPlane
);
309 array
->spec
[count
][RCOMP
] = solve_plane_chan(cx
, cy
, srPlane
);
310 array
->spec
[count
][GCOMP
] = solve_plane_chan(cx
, cy
, sgPlane
);
311 array
->spec
[count
][BCOMP
] = solve_plane_chan(cx
, cy
, sbPlane
);
315 const GLfloat invQ
= solve_plane_recip(cx
, cy
, vPlane
);
316 array
->texcoords
[0][count
][0] = solve_plane(cx
, cy
, sPlane
) * invQ
;
317 array
->texcoords
[0][count
][1] = solve_plane(cx
, cy
, tPlane
) * invQ
;
318 array
->texcoords
[0][count
][2] = solve_plane(cx
, cy
, uPlane
) * invQ
;
319 array
->lambda
[0][count
] = compute_lambda(sPlane
, tPlane
, vPlane
,
321 texWidth
, texHeight
);
323 #elif defined(DO_MULTITEX)
326 for (unit
= 0; unit
< ctx
->Const
.MaxTextureUnits
; unit
++) {
327 if (ctx
->Texture
.Unit
[unit
]._ReallyEnabled
) {
328 GLfloat invQ
= solve_plane_recip(cx
, cy
, vPlane
[unit
]);
329 array
->texcoords
[unit
][count
][0] = solve_plane(cx
, cy
, sPlane
[unit
]) * invQ
;
330 array
->texcoords
[unit
][count
][1] = solve_plane(cx
, cy
, tPlane
[unit
]) * invQ
;
331 array
->texcoords
[unit
][count
][2] = solve_plane(cx
, cy
, uPlane
[unit
]) * invQ
;
332 array
->lambda
[unit
][count
] = compute_lambda(sPlane
[unit
],
333 tPlane
[unit
], vPlane
[unit
], cx
, cy
, invQ
,
334 texWidth
[unit
], texHeight
[unit
]);
341 coverage
= compute_coveragef(pMin
, pMid
, pMax
, ix
, iy
);
349 span
.end
= (GLuint
) ix
- (GLuint
) startX
;
350 ASSERT(span
.interpMask
== 0);
351 #if defined(DO_MULTITEX) || defined(DO_TEX)
352 _mesa_write_texture_span(ctx
, &span
);
353 #elif defined(DO_RGBA)
354 _mesa_write_rgba_span(ctx
, &span
);
355 #elif defined(DO_INDEX)
356 _mesa_write_index_span(ctx
, &span
);
361 /* scan right to left */
362 const GLfloat
*pMin
= vMin
->win
;
363 const GLfloat
*pMid
= vMid
->win
;
364 const GLfloat
*pMax
= vMax
->win
;
365 const GLfloat dxdy
= majDx
/ majDy
;
366 const GLfloat xAdj
= dxdy
> 0 ? dxdy
: 0.0F
;
367 GLfloat x
= pMin
[0] - (yMin
- iyMin
) * dxdy
;
369 for (iy
= iyMin
; iy
< iyMax
; iy
++, x
+= dxdy
) {
370 GLint ix
, left
, startX
= (GLint
) (x
+ xAdj
);
372 GLfloat coverage
= 0.0F
;
374 /* make sure we're not past the window edge */
375 if (startX
>= ctx
->DrawBuffer
->_Xmax
) {
376 startX
= ctx
->DrawBuffer
->_Xmax
- 1;
379 /* skip fragments with zero coverage */
380 while (startX
>= 0) {
381 coverage
= compute_coveragef(pMin
, pMax
, pMid
, startX
, iy
);
387 /* enter interior of triangle */
390 while (coverage
> 0.0F
) {
391 /* (cx,cy) = center of fragment */
392 const GLfloat cx
= ix
+ 0.5F
, cy
= iy
+ 0.5F
;
393 struct span_arrays
*array
= span
.array
;
395 array
->coverage
[ix
] = (GLfloat
) compute_coveragei(pMin
, pMax
, pMid
, ix
, iy
);
397 array
->coverage
[ix
] = coverage
;
400 array
->z
[ix
] = (GLdepth
) solve_plane(cx
, cy
, zPlane
);
403 array
->fog
[ix
] = solve_plane(cx
, cy
, fogPlane
);
406 array
->rgba
[ix
][RCOMP
] = solve_plane_chan(cx
, cy
, rPlane
);
407 array
->rgba
[ix
][GCOMP
] = solve_plane_chan(cx
, cy
, gPlane
);
408 array
->rgba
[ix
][BCOMP
] = solve_plane_chan(cx
, cy
, bPlane
);
409 array
->rgba
[ix
][ACOMP
] = solve_plane_chan(cx
, cy
, aPlane
);
412 array
->index
[ix
] = (GLint
) solve_plane(cx
, cy
, iPlane
);
415 array
->spec
[ix
][RCOMP
] = solve_plane_chan(cx
, cy
, srPlane
);
416 array
->spec
[ix
][GCOMP
] = solve_plane_chan(cx
, cy
, sgPlane
);
417 array
->spec
[ix
][BCOMP
] = solve_plane_chan(cx
, cy
, sbPlane
);
421 const GLfloat invQ
= solve_plane_recip(cx
, cy
, vPlane
);
422 array
->texcoords
[0][ix
][0] = solve_plane(cx
, cy
, sPlane
) * invQ
;
423 array
->texcoords
[0][ix
][1] = solve_plane(cx
, cy
, tPlane
) * invQ
;
424 array
->texcoords
[0][ix
][2] = solve_plane(cx
, cy
, uPlane
) * invQ
;
425 array
->lambda
[0][ix
] = compute_lambda(sPlane
, tPlane
, vPlane
,
426 cx
, cy
, invQ
, texWidth
, texHeight
);
428 #elif defined(DO_MULTITEX)
431 for (unit
= 0; unit
< ctx
->Const
.MaxTextureUnits
; unit
++) {
432 if (ctx
->Texture
.Unit
[unit
]._ReallyEnabled
) {
433 GLfloat invQ
= solve_plane_recip(cx
, cy
, vPlane
[unit
]);
434 array
->texcoords
[unit
][ix
][0] = solve_plane(cx
, cy
, sPlane
[unit
]) * invQ
;
435 array
->texcoords
[unit
][ix
][1] = solve_plane(cx
, cy
, tPlane
[unit
]) * invQ
;
436 array
->texcoords
[unit
][ix
][2] = solve_plane(cx
, cy
, uPlane
[unit
]) * invQ
;
437 array
->lambda
[unit
][ix
] = compute_lambda(sPlane
[unit
],
449 coverage
= compute_coveragef(pMin
, pMax
, pMid
, ix
, iy
);
455 n
= (GLuint
) startX
- (GLuint
) ix
;
459 /* shift all values to the left */
460 /* XXX this is temporary */
462 struct span_arrays
*array
= span
.array
;
464 for (j
= 0; j
< (GLint
) n
; j
++) {
466 COPY_4V(array
->rgba
[j
], array
->rgba
[j
+ left
]);
469 COPY_4V(array
->spec
[j
], array
->spec
[j
+ left
]);
472 array
->index
[j
] = array
->index
[j
+ left
];
475 array
->z
[j
] = array
->z
[j
+ left
];
478 array
->fog
[j
] = array
->fog
[j
+ left
];
481 COPY_4V(array
->texcoords
[0][j
], array
->texcoords
[0][j
+ left
]);
483 #if defined(DO_MULTITEX) || defined(DO_TEX)
484 array
->lambda
[0][j
] = array
->lambda
[0][j
+ left
];
486 array
->coverage
[j
] = array
->coverage
[j
+ left
];
490 /* shift texcoords */
492 struct span_arrays
*array
= span
.array
;
494 for (unit
= 0; unit
< ctx
->Const
.MaxTextureUnits
; unit
++) {
495 if (ctx
->Texture
.Unit
[unit
]._ReallyEnabled
) {
497 for (j
= 0; j
< (GLint
) n
; j
++) {
498 array
->texcoords
[unit
][j
][0] = array
->texcoords
[unit
][j
+ left
][0];
499 array
->texcoords
[unit
][j
][1] = array
->texcoords
[unit
][j
+ left
][1];
500 array
->texcoords
[unit
][j
][2] = array
->texcoords
[unit
][j
+ left
][2];
501 array
->lambda
[unit
][j
] = array
->lambda
[unit
][j
+ left
];
511 ASSERT(span
.interpMask
== 0);
512 #if defined(DO_MULTITEX) || defined(DO_TEX)
513 _mesa_write_texture_span(ctx
, &span
);
514 #elif defined(DO_RGBA)
515 _mesa_write_rgba_span(ctx
, &span
);
516 #elif defined(DO_INDEX)
517 _mesa_write_index_span(ctx
, &span
);
552 #ifdef DO_OCCLUSION_TEST
553 #undef DO_OCCLUSION_TEST