source: trunk/src/opengl/mesa/span.c@ 2965

Last change on this file since 2965 was 2938, checked in by sandervl, 25 years ago

created
File size: 29.3 KB
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1/* $Id: span.c,v 1.1 2000-02-29 00:50:10 sandervl Exp $ */
2
3/*
4 * Mesa 3-D graphics library
5 * Version: 3.1
6 *
7 * Copyright (C) 1999 Brian Paul All Rights Reserved.
8 *
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:
15 *
16 * The above copyright notice and this permission notice shall be included
17 * in all copies or substantial portions of the Software.
18 *
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.
25 */
26
27
28
29
30
31/*
32 * pixel span rasterization:
33 * These functions simulate the rasterization pipeline.
34 */
35
36
37#ifdef PC_HEADER
38#include "all.h"
39#else
40#ifndef XFree86Server
41#include <assert.h>
42#include <string.h>
43#else
44#include "GL/xf86glx.h"
45#endif
46#include "alpha.h"
47#include "alphabuf.h"
48#include "blend.h"
49#include "depth.h"
50#include "fog.h"
51#include "logic.h"
52#include "macros.h"
53#include "masking.h"
54#include "scissor.h"
55#include "span.h"
56#include "stencil.h"
57#include "texture.h"
58#include "types.h"
59#endif
60
61
62
63
64/*
65 * Apply the current polygon stipple pattern to a span of pixels.
66 */
67static void stipple_polygon_span( GLcontext *ctx,
68 GLuint n, GLint x, GLint y, GLubyte mask[] )
69{
70 register GLuint i, m, stipple, highbit=0x80000000;
71
72 stipple = ctx->PolygonStipple[y % 32];
73 m = highbit >> (GLuint) (x % 32);
74
75 for (i=0;i<n;i++) {
76 if ((m & stipple)==0) {
77 mask[i] = 0;
78 }
79 m = m >> 1;
80 if (m==0) {
81 m = 0x80000000;
82 }
83 }
84}
85
86
87
88/*
89 * Clip a pixel span to the current buffer/window boundaries.
90 * Return: 0 = all pixels clipped
91 * 1 = at least one pixel is visible
92 */
93static GLuint clip_span( GLcontext *ctx,
94 GLint n, GLint x, GLint y, GLubyte mask[] )
95{
96 GLint i;
97
98 /* Clip to top and bottom */
99 if (y<0 || y>=ctx->Buffer->Height) {
100 return 0;
101 }
102
103 /* Clip to left and right */
104 if (x>=0 && x+n<=ctx->Buffer->Width) {
105 /* no clipping needed */
106 return 1;
107 }
108 else if (x+n<=0) {
109 /* completely off left side */
110 return 0;
111 }
112 else if (x>=ctx->Buffer->Width) {
113 /* completely off right side */
114 return 0;
115 }
116 else {
117 /* clip-test each pixel, this could be done better */
118 for (i=0;i<n;i++) {
119 if (x+i<0 || x+i>=ctx->Buffer->Width) {
120 mask[i] = 0;
121 }
122 }
123 return 1;
124 }
125}
126
127
128
129/*
130 * Draw to more than one color buffer (or none).
131 */
132static void multi_write_index_span( GLcontext *ctx, GLuint n,
133 GLint x, GLint y, const GLuint indexes[],
134 const GLubyte mask[] )
135{
136 GLuint bufferBit;
137
138 if (ctx->Color.DrawBuffer == GL_NONE)
139 return;
140
141 /* loop over four possible dest color buffers */
142 for (bufferBit = 1; bufferBit <= 8; bufferBit = bufferBit << 1) {
143 if (bufferBit & ctx->Color.DrawDestMask) {
144 GLuint indexTmp[MAX_WIDTH];
145 ASSERT(n < MAX_WIDTH);
146
147 if (bufferBit == FRONT_LEFT_BIT)
148 (*ctx->Driver.SetBuffer)( ctx, GL_FRONT_LEFT);
149 else if (bufferBit == FRONT_RIGHT_BIT)
150 (*ctx->Driver.SetBuffer)( ctx, GL_FRONT_RIGHT);
151 else if (bufferBit == BACK_LEFT_BIT)
152 (*ctx->Driver.SetBuffer)( ctx, GL_BACK_LEFT);
153 else
154 (*ctx->Driver.SetBuffer)( ctx, GL_BACK_RIGHT);
155
156 /* make copy of incoming indexes */
157 MEMCPY( indexTmp, indexes, n * sizeof(GLuint) );
158 if (ctx->Color.SWLogicOpEnabled) {
159 gl_logicop_ci_span( ctx, n, x, y, indexTmp, mask );
160 }
161 if (ctx->Color.SWmasking) {
162 gl_mask_index_span( ctx, n, x, y, indexTmp );
163 }
164 (*ctx->Driver.WriteCI32Span)( ctx, n, x, y, indexTmp, mask );
165 }
166 }
167
168 /* restore default dest buffer */
169 (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Color.DriverDrawBuffer);
170}
171
172
173
174/*
175 * Write a horizontal span of color index pixels to the frame buffer.
176 * Stenciling, Depth-testing, etc. are done as needed.
177 * Input: n - number of pixels in the span
178 * x, y - location of leftmost pixel in the span
179 * z - array of [n] z-values
180 * index - array of [n] color indexes
181 * primitive - either GL_POINT, GL_LINE, GL_POLYGON, or GL_BITMAP
182 */
183void gl_write_index_span( GLcontext *ctx,
184 GLuint n, GLint x, GLint y, const GLdepth z[],
185 GLuint indexIn[], GLenum primitive )
186{
187 GLubyte mask[MAX_WIDTH];
188 GLuint indexBackup[MAX_WIDTH];
189 GLuint *index; /* points to indexIn or indexBackup */
190
191 /* init mask to 1's (all pixels are to be written) */
192 MEMSET(mask, 1, n);
193
194 if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
195 if (clip_span(ctx,n,x,y,mask)==0) {
196 return;
197 }
198 }
199
200 if ((primitive==GL_BITMAP && ctx->MutablePixels)
201 || (ctx->RasterMask & MULTI_DRAW_BIT)) {
202 /* Make copy of color indexes */
203 MEMCPY( indexBackup, indexIn, n * sizeof(GLuint) );
204 index = indexBackup;
205 }
206 else {
207 index = indexIn;
208 }
209
210 /* Per-pixel fog */
211 if (ctx->Fog.Enabled && (primitive==GL_BITMAP || ctx->FogMode == FOG_FRAGMENT)) {
212 gl_fog_ci_pixels( ctx, n, z, index );
213 }
214
215 /* Do the scissor test */
216 if (ctx->Scissor.Enabled) {
217 if (gl_scissor_span( ctx, n, x, y, mask )==0) {
218 return;
219 }
220 }
221
222 /* Polygon Stippling */
223 if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
224 stipple_polygon_span( ctx, n, x, y, mask );
225 }
226
227 if (ctx->Stencil.Enabled) {
228 /* first stencil test */
229 if (gl_stencil_span( ctx, n, x, y, mask )==0) {
230 return;
231 }
232 /* depth buffering w/ stencil */
233 gl_depth_stencil_span( ctx, n, x, y, z, mask );
234 }
235 else if (ctx->Depth.Test) {
236 /* regular depth testing */
237 if ((*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask )==0) return;
238 }
239
240 if (ctx->RasterMask & MULTI_DRAW_BIT) {
241 /* draw to zero or two or more buffers */
242 multi_write_index_span( ctx, n, x, y, index, mask );
243 }
244 else {
245 /* normal situation: draw to exactly one buffer */
246 if (ctx->Color.SWLogicOpEnabled) {
247 gl_logicop_ci_span( ctx, n, x, y, index, mask );
248 }
249 if (ctx->Color.SWmasking) {
250 gl_mask_index_span( ctx, n, x, y, index );
251 }
252
253 /* write pixels */
254 (*ctx->Driver.WriteCI32Span)( ctx, n, x, y, index, mask );
255 }
256}
257
258
259
260
261void gl_write_monoindex_span( GLcontext *ctx,
262 GLuint n, GLint x, GLint y, const GLdepth z[],
263 GLuint index, GLenum primitive )
264{
265 GLubyte mask[MAX_WIDTH];
266 GLuint i;
267
268 /* init mask to 1's (all pixels are to be written) */
269 MEMSET(mask, 1, n);
270
271 if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
272 if (clip_span( ctx, n, x, y, mask)==0) {
273 return;
274 }
275 }
276
277 /* Do the scissor test */
278 if (ctx->Scissor.Enabled) {
279 if (gl_scissor_span( ctx, n, x, y, mask )==0) {
280 return;
281 }
282 }
283
284 /* Polygon Stippling */
285 if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
286 stipple_polygon_span( ctx, n, x, y, mask );
287 }
288
289 if (ctx->Stencil.Enabled) {
290 /* first stencil test */
291 if (gl_stencil_span( ctx, n, x, y, mask )==0) {
292 return;
293 }
294 /* depth buffering w/ stencil */
295 gl_depth_stencil_span( ctx, n, x, y, z, mask );
296 }
297 else if (ctx->Depth.Test) {
298 /* regular depth testing */
299 if ((*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask )==0) return;
300 }
301
302 if (ctx->Color.DrawBuffer == GL_NONE) {
303 /* write no pixels */
304 return;
305 }
306
307 if ((ctx->Fog.Enabled && (primitive==GL_BITMAP || ctx->FogMode==FOG_FRAGMENT))
308 || ctx->Color.SWLogicOpEnabled || ctx->Color.SWmasking) {
309 /* different index per pixel */
310 GLuint indexes[MAX_WIDTH];
311 for (i=0;i<n;i++) {
312 indexes[i] = index;
313 }
314
315 if (ctx->Fog.Enabled && (primitive==GL_BITMAP || ctx->FogMode==FOG_FRAGMENT)) {
316 gl_fog_ci_pixels( ctx, n, z, indexes );
317 }
318
319 if (ctx->Color.SWLogicOpEnabled) {
320 gl_logicop_ci_span( ctx, n, x, y, indexes, mask );
321 }
322
323 if (ctx->Color.SWmasking) {
324 gl_mask_index_span( ctx, n, x, y, indexes );
325 }
326
327 if (ctx->RasterMask & MULTI_DRAW_BIT) {
328 /* draw to zero or two or more buffers */
329 multi_write_index_span( ctx, n, x, y, indexes, mask );
330 }
331 else {
332 /* normal situation: draw to exactly one buffer */
333 if (ctx->Color.SWLogicOpEnabled) {
334 gl_logicop_ci_span( ctx, n, x, y, indexes, mask );
335 }
336 if (ctx->Color.SWmasking) {
337 gl_mask_index_span( ctx, n, x, y, indexes );
338 }
339 (*ctx->Driver.WriteCI32Span)( ctx, n, x, y, indexes, mask );
340 }
341 }
342 else {
343 /* same color index for all pixels */
344 ASSERT(!ctx->Color.SWLogicOpEnabled);
345 ASSERT(!ctx->Color.SWmasking);
346 if (ctx->RasterMask & MULTI_DRAW_BIT) {
347 /* draw to zero or two or more buffers */
348 GLuint indexes[MAX_WIDTH];
349 for (i=0;i<n;i++)
350 indexes[i] = index;
351 multi_write_index_span( ctx, n, x, y, indexes, mask );
352 }
353 else {
354 /* normal situation: draw to exactly one buffer */
355 (*ctx->Driver.WriteMonoCISpan)( ctx, n, x, y, mask );
356 }
357 }
358}
359
360
361
362/*
363 * Draw to more than one RGBA color buffer (or none).
364 */
365static void multi_write_rgba_span( GLcontext *ctx, GLuint n,
366 GLint x, GLint y, CONST GLubyte rgba[][4],
367 const GLubyte mask[] )
368{
369 GLuint bufferBit;
370
371 if (ctx->Color.DrawBuffer == GL_NONE)
372 return;
373
374 /* loop over four possible dest color buffers */
375 for (bufferBit = 1; bufferBit <= 8; bufferBit = bufferBit << 1) {
376 if (bufferBit & ctx->Color.DrawDestMask) {
377 GLubyte rgbaTmp[MAX_WIDTH][4];
378 ASSERT(n < MAX_WIDTH);
379
380 if (bufferBit == FRONT_LEFT_BIT) {
381 (*ctx->Driver.SetBuffer)( ctx, GL_FRONT_LEFT);
382 ctx->Buffer->Alpha = ctx->Buffer->FrontLeftAlpha;
383 }
384 else if (bufferBit == FRONT_RIGHT_BIT) {
385 (*ctx->Driver.SetBuffer)( ctx, GL_FRONT_RIGHT);
386 ctx->Buffer->Alpha = ctx->Buffer->FrontRightAlpha;
387 }
388 else if (bufferBit == BACK_LEFT_BIT) {
389 (*ctx->Driver.SetBuffer)( ctx, GL_BACK_LEFT);
390 ctx->Buffer->Alpha = ctx->Buffer->BackLeftAlpha;
391 }
392 else {
393 (*ctx->Driver.SetBuffer)( ctx, GL_BACK_RIGHT);
394 ctx->Buffer->Alpha = ctx->Buffer->BackRightAlpha;
395 }
396
397 /* make copy of incoming colors */
398 MEMCPY( rgbaTmp, rgba, 4 * n * sizeof(GLubyte) );
399
400 if (ctx->Color.SWLogicOpEnabled) {
401 gl_logicop_rgba_span( ctx, n, x, y, rgbaTmp, mask );
402 }
403 else if (ctx->Color.BlendEnabled) {
404 gl_blend_span( ctx, n, x, y, rgbaTmp, mask );
405 }
406 if (ctx->Color.SWmasking) {
407 gl_mask_rgba_span( ctx, n, x, y, rgbaTmp );
408 }
409
410 (*ctx->Driver.WriteRGBASpan)( ctx, n, x, y,
411 (const GLubyte (*)[4]) rgbaTmp, mask );
412 if (ctx->RasterMask & ALPHABUF_BIT) {
413 gl_write_alpha_span( ctx, n, x, y,
414 (const GLubyte (*)[4])rgbaTmp, mask );
415 }
416 }
417 }
418
419 /* restore default dest buffer */
420 (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Color.DriverDrawBuffer );
421}
422
423
424
425void gl_write_rgba_span( GLcontext *ctx,
426 GLuint n, GLint x, GLint y, const GLdepth z[],
427 GLubyte rgbaIn[][4],
428 GLenum primitive )
429{
430 GLubyte mask[MAX_WIDTH];
431 GLboolean write_all = GL_TRUE;
432 GLubyte rgbaBackup[MAX_WIDTH][4];
433 GLubyte (*rgba)[4];
434 const GLubyte *Null = 0;
435
436 /* init mask to 1's (all pixels are to be written) */
437 MEMSET(mask, 1, n);
438
439 if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
440 if (clip_span( ctx,n,x,y,mask)==0) {
441 return;
442 }
443 write_all = GL_FALSE;
444 }
445
446 if ((primitive==GL_BITMAP && ctx->MutablePixels)
447 || (ctx->RasterMask & MULTI_DRAW_BIT)) {
448 /* must make a copy of the colors since they may be modified */
449 MEMCPY( rgbaBackup, rgbaIn, 4 * n * sizeof(GLubyte) );
450 rgba = rgbaBackup;
451 }
452 else {
453 rgba = rgbaIn;
454 }
455
456 /* Per-pixel fog */
457 if (ctx->Fog.Enabled && (primitive==GL_BITMAP || ctx->FogMode==FOG_FRAGMENT)) {
458 gl_fog_rgba_pixels( ctx, n, z, rgba );
459 }
460
461 /* Do the scissor test */
462 if (ctx->Scissor.Enabled) {
463 if (gl_scissor_span( ctx, n, x, y, mask )==0) {
464 return;
465 }
466 write_all = GL_FALSE;
467 }
468
469 /* Polygon Stippling */
470 if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
471 stipple_polygon_span( ctx, n, x, y, mask );
472 write_all = GL_FALSE;
473 }
474
475 /* Do the alpha test */
476 if (ctx->Color.AlphaEnabled) {
477 if (gl_alpha_test( ctx, n, (const GLubyte (*)[4]) rgba, mask )==0) {
478 return;
479 }
480 write_all = GL_FALSE;
481 }
482
483 if (ctx->Stencil.Enabled) {
484 /* first stencil test */
485 if (gl_stencil_span( ctx, n, x, y, mask )==0) {
486 return;
487 }
488 /* depth buffering w/ stencil */
489 gl_depth_stencil_span( ctx, n, x, y, z, mask );
490 write_all = GL_FALSE;
491 }
492 else if (ctx->Depth.Test) {
493 /* regular depth testing */
494 GLuint m = (*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask );
495 if (m==0) {
496 return;
497 }
498 if (m<n) {
499 write_all = GL_FALSE;
500 }
501 }
502
503 if (ctx->RasterMask & MULTI_DRAW_BIT) {
504 multi_write_rgba_span( ctx, n, x, y,
505 (const GLubyte (*)[4]) rgba,
506 write_all ? Null : mask );
507 }
508 else {
509 /* normal: write to exactly one buffer */
510 /* logic op or blending */
511 if (ctx->Color.SWLogicOpEnabled) {
512 gl_logicop_rgba_span( ctx, n, x, y, rgba, mask );
513 }
514 else if (ctx->Color.BlendEnabled) {
515 gl_blend_span( ctx, n, x, y, rgba, mask );
516 }
517
518 /* Color component masking */
519 if (ctx->Color.SWmasking) {
520 gl_mask_rgba_span( ctx, n, x, y, rgba );
521 }
522
523 /* write pixels */
524 (*ctx->Driver.WriteRGBASpan)( ctx, n, x, y,
525 (const GLubyte (*)[4]) rgba,
526 write_all ? Null : mask );
527
528 if (ctx->RasterMask & ALPHABUF_BIT) {
529 gl_write_alpha_span( ctx, n, x, y,
530 (const GLubyte (*)[4]) rgba,
531 write_all ? Null : mask );
532 }
533
534 }
535}
536
537
538
539/*
540 * Write a horizontal span of color pixels to the frame buffer.
541 * The color is initially constant for the whole span.
542 * Alpha-testing, stenciling, depth-testing, and blending are done as needed.
543 * Input: n - number of pixels in the span
544 * x, y - location of leftmost pixel in the span
545 * z - array of [n] z-values
546 * r, g, b, a - the color of the pixels
547 * primitive - either GL_POINT, GL_LINE, GL_POLYGON or GL_BITMAP.
548 */
549void gl_write_monocolor_span( GLcontext *ctx,
550 GLuint n, GLint x, GLint y, const GLdepth z[],
551 const GLubyte color[4],
552 GLenum primitive )
553{
554 GLuint i;
555 GLubyte mask[MAX_WIDTH];
556 GLboolean write_all = GL_TRUE;
557 GLubyte rgba[MAX_WIDTH][4];
558 const GLubyte *Null = 0;
559
560 /* init mask to 1's (all pixels are to be written) */
561 MEMSET(mask, 1, n);
562
563 if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
564 if (clip_span( ctx,n,x,y,mask)==0) {
565 return;
566 }
567 write_all = GL_FALSE;
568 }
569
570 /* Do the scissor test */
571 if (ctx->Scissor.Enabled) {
572 if (gl_scissor_span( ctx, n, x, y, mask )==0) {
573 return;
574 }
575 write_all = GL_FALSE;
576 }
577
578 /* Polygon Stippling */
579 if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
580 stipple_polygon_span( ctx, n, x, y, mask );
581 write_all = GL_FALSE;
582 }
583
584 /* Do the alpha test */
585 if (ctx->Color.AlphaEnabled) {
586 for (i=0;i<n;i++) {
587 rgba[i][ACOMP] = color[ACOMP];
588 }
589 if (gl_alpha_test( ctx, n, (const GLubyte (*)[4])rgba, mask )==0) {
590 return;
591 }
592 write_all = GL_FALSE;
593 }
594
595 if (ctx->Stencil.Enabled) {
596 /* first stencil test */
597 if (gl_stencil_span( ctx, n, x, y, mask )==0) {
598 return;
599 }
600 /* depth buffering w/ stencil */
601 gl_depth_stencil_span( ctx, n, x, y, z, mask );
602 write_all = GL_FALSE;
603 }
604 else if (ctx->Depth.Test) {
605 /* regular depth testing */
606 GLuint m = (*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask );
607 if (m==0) {
608 return;
609 }
610 if (m<n) {
611 write_all = GL_FALSE;
612 }
613 }
614
615 if (ctx->Color.DrawBuffer == GL_NONE) {
616 /* write no pixels */
617 return;
618 }
619
620 if (ctx->Color.BlendEnabled || ctx->Color.SWLogicOpEnabled
621 || ctx->Color.SWmasking) {
622 /* assign same color to each pixel */
623 for (i=0;i<n;i++) {
624 if (mask[i]) {
625 COPY_4UBV(rgba[i], color);
626 }
627 }
628
629 if (ctx->RasterMask & MULTI_DRAW_BIT) {
630 multi_write_rgba_span( ctx, n, x, y, (const GLubyte (*)[4]) rgba,
631 mask );
632 }
633 else {
634 /* normal: write to exactly one buffer */
635 if (ctx->Color.SWLogicOpEnabled) {
636 gl_logicop_rgba_span( ctx, n, x, y, rgba, mask );
637 }
638 else if (ctx->Color.BlendEnabled) {
639 gl_blend_span( ctx, n, x, y, rgba, mask );
640 }
641
642 /* Color component masking */
643 if (ctx->Color.SWmasking) {
644 gl_mask_rgba_span( ctx, n, x, y, rgba );
645 }
646
647 /* write pixels */
648 (*ctx->Driver.WriteRGBASpan)( ctx, n, x, y,
649 (const GLubyte (*)[4]) rgba,
650 write_all ? Null : mask );
651 if (ctx->RasterMask & ALPHABUF_BIT) {
652 gl_write_alpha_span( ctx, n, x, y,
653 (const GLubyte (*)[4]) rgba,
654 write_all ? Null : mask );
655 }
656 }
657 }
658 else {
659 /* same color for all pixels */
660 ASSERT(!ctx->Color.BlendEnabled);
661 ASSERT(!ctx->Color.SWLogicOpEnabled);
662 ASSERT(!ctx->Color.SWmasking);
663
664 if (ctx->RasterMask & MULTI_DRAW_BIT) {
665 for (i=0;i<n;i++) {
666 if (mask[i]) {
667 COPY_4UBV(rgba[i], color);
668 }
669 }
670 multi_write_rgba_span( ctx, n, x, y,
671 (const GLubyte (*)[4]) rgba,
672 mask );
673 }
674 else {
675 (*ctx->Driver.WriteMonoRGBASpan)( ctx, n, x, y, mask );
676 if (ctx->RasterMask & ALPHABUF_BIT) {
677 gl_write_mono_alpha_span( ctx, n, x, y, (GLubyte) color[ACOMP],
678 write_all ? Null : mask );
679 }
680 }
681 }
682}
683
684
685
686/*
687 * Add specular color to base color. This is used only when
688 * GL_LIGHT_MODEL_COLOR_CONTROL = GL_SEPARATE_SPECULAR_COLOR.
689 */
690static void add_colors(GLuint n, GLubyte rgba[][4], CONST GLubyte specular[][4] )
691{
692 GLuint i;
693 for (i=0; i<n; i++) {
694 GLint r = rgba[i][RCOMP] + specular[i][RCOMP];
695 GLint g = rgba[i][GCOMP] + specular[i][GCOMP];
696 GLint b = rgba[i][BCOMP] + specular[i][BCOMP];
697 rgba[i][RCOMP] = (GLubyte) MIN2(r, 255);
698 rgba[i][GCOMP] = (GLubyte) MIN2(g, 255);
699 rgba[i][BCOMP] = (GLubyte) MIN2(b, 255);
700 }
701}
702
703
704/*
705 * Write a horizontal span of textured pixels to the frame buffer.
706 * The color of each pixel is different.
707 * Alpha-testing, stenciling, depth-testing, and blending are done
708 * as needed.
709 * Input: n - number of pixels in the span
710 * x, y - location of leftmost pixel in the span
711 * z - array of [n] z-values
712 * s, t - array of (s,t) texture coordinates for each pixel
713 * lambda - array of texture lambda values
714 * rgba - array of [n] color components
715 * primitive - either GL_POINT, GL_LINE, GL_POLYGON or GL_BITMAP.
716 */
717void gl_write_texture_span( GLcontext *ctx,
718 GLuint n, GLint x, GLint y, const GLdepth z[],
719 const GLfloat s[], const GLfloat t[],
720 const GLfloat u[], GLfloat lambda[],
721 GLubyte rgbaIn[][4], CONST GLubyte spec[][4],
722 GLenum primitive )
723{
724 GLubyte mask[MAX_WIDTH];
725 GLboolean write_all = GL_TRUE;
726 GLubyte rgbaBackup[MAX_WIDTH][4];
727 GLubyte (*rgba)[4]; /* points to either rgbaIn or rgbaBackup */
728 const GLubyte *Null = 0;
729
730 /* init mask to 1's (all pixels are to be written) */
731 MEMSET(mask, 1, n);
732
733 if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
734 if (clip_span(ctx, n, x, y, mask)==0) {
735 return;
736 }
737 write_all = GL_FALSE;
738 }
739
740
741 if (primitive==GL_BITMAP || (ctx->RasterMask & MULTI_DRAW_BIT)) {
742 /* must make a copy of the colors since they may be modified */
743 MEMCPY(rgbaBackup, rgbaIn, 4 * sizeof(GLubyte));
744 rgba = rgbaBackup;
745 }
746 else {
747 rgba = rgbaIn;
748 }
749
750 /* Texture */
751 ASSERT(ctx->Texture.Enabled);
752 gl_texture_pixels( ctx, 0, n, s, t, u, lambda, rgba );
753
754 /* Add base and specular colors */
755 if (spec && ctx->Light.Enabled
756 && ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)
757 add_colors( n, rgba, spec ); /* rgba = rgba + spec */
758
759 /* Per-pixel fog */
760 if (ctx->Fog.Enabled && (primitive==GL_BITMAP || ctx->FogMode==FOG_FRAGMENT)) {
761 gl_fog_rgba_pixels( ctx, n, z, rgba );
762 }
763
764 /* Do the scissor test */
765 if (ctx->Scissor.Enabled) {
766 if (gl_scissor_span( ctx, n, x, y, mask )==0) {
767 return;
768 }
769 write_all = GL_FALSE;
770 }
771
772 /* Polygon Stippling */
773 if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
774 stipple_polygon_span( ctx, n, x, y, mask );
775 write_all = GL_FALSE;
776 }
777
778 /* Do the alpha test */
779 if (ctx->Color.AlphaEnabled) {
780 if (gl_alpha_test( ctx, n, (const GLubyte (*)[4]) rgba, mask )==0) {
781 return;
782 }
783 write_all = GL_FALSE;
784 }
785
786 if (ctx->Stencil.Enabled) {
787 /* first stencil test */
788 if (gl_stencil_span( ctx, n, x, y, mask )==0) {
789 return;
790 }
791 /* depth buffering w/ stencil */
792 gl_depth_stencil_span( ctx, n, x, y, z, mask );
793 write_all = GL_FALSE;
794 }
795 else if (ctx->Depth.Test) {
796 /* regular depth testing */
797 GLuint m = (*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask );
798 if (m==0) {
799 return;
800 }
801 if (m<n) {
802 write_all = GL_FALSE;
803 }
804 }
805
806 if (ctx->RasterMask & MULTI_DRAW_BIT) {
807 multi_write_rgba_span( ctx, n, x, y, (const GLubyte (*)[4])rgba,
808 write_all ? Null : mask );
809 }
810 else {
811 /* normal: write to exactly one buffer */
812 if (ctx->Color.SWLogicOpEnabled) {
813 gl_logicop_rgba_span( ctx, n, x, y, rgba, mask );
814 }
815 else if (ctx->Color.BlendEnabled) {
816 gl_blend_span( ctx, n, x, y, rgba, mask );
817 }
818 if (ctx->Color.SWmasking) {
819 gl_mask_rgba_span( ctx, n, x, y, rgba );
820 }
821
822 (*ctx->Driver.WriteRGBASpan)( ctx, n, x, y, (const GLubyte (*)[4])rgba,
823 write_all ? Null : mask );
824 if (ctx->RasterMask & ALPHABUF_BIT) {
825 gl_write_alpha_span( ctx, n, x, y, (const GLubyte (*)[4]) rgba,
826 write_all ? Null : mask );
827 }
828 }
829}
830
831
832
833/*
834 * As above but perform multiple stages of texture application.
835 * Input: texUnits - number of texture units to apply
836 */
837void gl_write_multitexture_span( GLcontext *ctx, GLuint texUnits,
838 GLuint n, GLint x, GLint y,
839 const GLdepth z[],
840 CONST GLfloat s[][MAX_WIDTH],
841 CONST GLfloat t[][MAX_WIDTH],
842 CONST GLfloat u[][MAX_WIDTH],
843 GLfloat lambda[][MAX_WIDTH],
844 GLubyte rgbaIn[][4], CONST GLubyte spec[][4],
845 GLenum primitive )
846{
847 GLubyte mask[MAX_WIDTH];
848 GLboolean write_all = GL_TRUE;
849 GLubyte rgbaBackup[MAX_WIDTH][4];
850 GLubyte (*rgba)[4]; /* points to either rgbaIn or rgbaBackup */
851 GLuint i;
852 const GLubyte *Null = 0;
853
854 /* init mask to 1's (all pixels are to be written) */
855 MEMSET(mask, 1, n);
856
857 if ((ctx->RasterMask & WINCLIP_BIT) || primitive==GL_BITMAP) {
858 if (clip_span(ctx, n, x, y, mask)==0) {
859 return;
860 }
861 write_all = GL_FALSE;
862 }
863
864
865 if (primitive==GL_BITMAP || (ctx->RasterMask & MULTI_DRAW_BIT)) {
866 /* must make a copy of the colors since they may be modified */
867 MEMCPY(rgbaBackup, rgbaIn, 4 * sizeof(GLubyte));
868 rgba = rgbaBackup;
869 }
870 else {
871 rgba = rgbaIn;
872 }
873
874 /* Texture */
875 ASSERT(ctx->Texture.Enabled);
876 ASSERT(texUnits <= MAX_TEXTURE_UNITS);
877 for (i=0;i<texUnits;i++) {
878 gl_texture_pixels( ctx, i, n, s[i], t[i], u[i], lambda[i], rgba );
879 }
880
881 /* Add base and specular colors */
882 if (spec && ctx->Light.Enabled
883 && ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)
884 add_colors( n, rgba, spec ); /* rgba = rgba + spec */
885
886 /* Per-pixel fog */
887 if (ctx->Fog.Enabled && (primitive==GL_BITMAP || ctx->FogMode==FOG_FRAGMENT)) {
888 gl_fog_rgba_pixels( ctx, n, z, rgba );
889 }
890
891 /* Do the scissor test */
892 if (ctx->Scissor.Enabled) {
893 if (gl_scissor_span( ctx, n, x, y, mask )==0) {
894 return;
895 }
896 write_all = GL_FALSE;
897 }
898
899 /* Polygon Stippling */
900 if (ctx->Polygon.StippleFlag && primitive==GL_POLYGON) {
901 stipple_polygon_span( ctx, n, x, y, mask );
902 write_all = GL_FALSE;
903 }
904
905 /* Do the alpha test */
906 if (ctx->Color.AlphaEnabled) {
907 if (gl_alpha_test( ctx, n, (const GLubyte (*)[4])rgba, mask )==0) {
908 return;
909 }
910 write_all = GL_FALSE;
911 }
912
913 if (ctx->Stencil.Enabled) {
914 /* first stencil test */
915 if (gl_stencil_span( ctx, n, x, y, mask )==0) {
916 return;
917 }
918 /* depth buffering w/ stencil */
919 gl_depth_stencil_span( ctx, n, x, y, z, mask );
920 write_all = GL_FALSE;
921 }
922 else if (ctx->Depth.Test) {
923 /* regular depth testing */
924 GLuint m = (*ctx->Driver.DepthTestSpan)( ctx, n, x, y, z, mask );
925 if (m==0) {
926 return;
927 }
928 if (m<n) {
929 write_all = GL_FALSE;
930 }
931 }
932
933 if (ctx->RasterMask & MULTI_DRAW_BIT) {
934 multi_write_rgba_span( ctx, n, x, y, (const GLubyte (*)[4]) rgba, write_all ? Null : mask );
935 }
936 else {
937 /* normal: write to exactly one buffer */
938
939 if (ctx->Color.SWLogicOpEnabled) {
940 gl_logicop_rgba_span( ctx, n, x, y, rgba, mask );
941 }
942 else if (ctx->Color.BlendEnabled) {
943 gl_blend_span( ctx, n, x, y, rgba, mask );
944 }
945 if (ctx->Color.SWmasking) {
946 gl_mask_rgba_span( ctx, n, x, y, rgba );
947 }
948
949 (*ctx->Driver.WriteRGBASpan)( ctx, n, x, y, (const GLubyte (*)[4])rgba, write_all ? Null : mask );
950 if (ctx->RasterMask & ALPHABUF_BIT) {
951 gl_write_alpha_span( ctx, n, x, y, (const GLubyte (*)[4])rgba,
952 write_all ? Null : mask );
953 }
954 }
955}
956
957
958
959/*
960 * Read RGBA pixels from frame buffer. Clipping will be done to prevent
961 * reading ouside the buffer's boundaries.
962 */
963void gl_read_rgba_span( GLcontext *ctx,
964 GLuint n, GLint x, GLint y,
965 GLubyte rgba[][4] )
966{
967 if (y<0 || y>=ctx->Buffer->Height || x>=ctx->Buffer->Width) {
968 /* completely above, below, or right */
969 MEMSET( rgba, 0, 4 * n * sizeof(GLubyte)); /*XXX maybe leave undefined?*/
970 }
971 else {
972 GLint skip, length;
973 if (x < 0) {
974 /* left edge clippping */
975 skip = -x;
976 length = (GLint) n - skip;
977 if (length < 0) {
978 /* completely left of window */
979 return;
980 }
981 if (length > ctx->Buffer->Width) {
982 length = ctx->Buffer->Width;
983 }
984 }
985 else if ((GLint) (x + n) > ctx->Buffer->Width) {
986 /* right edge clipping */
987 skip = 0;
988 length = ctx->Buffer->Width - x;
989 if (length < 0) {
990 /* completely to right of window */
991 return;
992 }
993 }
994 else {
995 /* no clipping */
996 skip = 0;
997 length = (GLint) n;
998 }
999
1000 (*ctx->Driver.ReadRGBASpan)( ctx, length, x + skip, y, rgba + skip );
1001 if (ctx->Visual->SoftwareAlpha) {
1002 gl_read_alpha_span( ctx, length, x + skip, y, rgba + skip );
1003 }
1004 }
1005}
1006
1007
1008
1009
1010/*
1011 * Read CI pixels from frame buffer. Clipping will be done to prevent
1012 * reading ouside the buffer's boundaries.
1013 */
1014void gl_read_index_span( GLcontext *ctx,
1015 GLuint n, GLint x, GLint y, GLuint indx[] )
1016{
1017 register GLuint i;
1018
1019 if (y<0 || y>=ctx->Buffer->Height || x>=ctx->Buffer->Width) {
1020 /* completely above, below, or right */
1021 for (i=0;i<n;i++) {
1022 indx[i] = 0;
1023 }
1024 }
1025 else {
1026 GLint skip, length;
1027 if (x < 0) {
1028 /* left edge clippping */
1029 skip = -x;
1030 length = (GLint) n - skip;
1031 if (length < 0) {
1032 /* completely left of window */
1033 return;
1034 }
1035 if (length > ctx->Buffer->Width) {
1036 length = ctx->Buffer->Width;
1037 }
1038 }
1039 else if ((GLint) (x + n) > ctx->Buffer->Width) {
1040 /* right edge clipping */
1041 skip = 0;
1042 length = ctx->Buffer->Width - x;
1043 if (length < 0) {
1044 /* completely to right of window */
1045 return;
1046 }
1047 }
1048 else {
1049 /* no clipping */
1050 skip = 0;
1051 length = (GLint) n;
1052 }
1053
1054 (*ctx->Driver.ReadCI32Span)( ctx, length, skip + x, y, indx + skip );
1055 }
1056}
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