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Roll the multi_write_rgba_span() code into _swrast_write_rgba_span().
[mesa.git] / src / mesa / swrast / s_span.c
1 /*
2 * Mesa 3-D graphics library
3 * Version: 6.5
4 *
5 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26 /**
27 * \file swrast/s_span.c
28 * \brief Span processing functions used by all rasterization functions.
29 * This is where all the per-fragment tests are performed
30 * \author Brian Paul
31 */
32
33 #include "glheader.h"
34 #include "colormac.h"
35 #include "context.h"
36 #include "macros.h"
37 #include "imports.h"
38
39 #include "s_atifragshader.h"
40 #include "s_alpha.h"
41 #include "s_arbshader.h"
42 #include "s_blend.h"
43 #include "s_context.h"
44 #include "s_depth.h"
45 #include "s_fog.h"
46 #include "s_logic.h"
47 #include "s_masking.h"
48 #include "s_nvfragprog.h"
49 #include "s_span.h"
50 #include "s_stencil.h"
51 #include "s_texcombine.h"
52
53
54 /**
55 * Init span's Z interpolation values to the RasterPos Z.
56 * Used during setup for glDraw/CopyPixels.
57 */
58 void
59 _swrast_span_default_z( GLcontext *ctx, struct sw_span *span )
60 {
61 const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;
62 if (ctx->DrawBuffer->Visual.depthBits <= 16)
63 span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);
64 else
65 span->z = (GLint) (ctx->Current.RasterPos[2] * depthMax + 0.5F);
66 span->zStep = 0;
67 span->interpMask |= SPAN_Z;
68 }
69
70
71 /**
72 * Init span's fog interpolation values to the RasterPos fog.
73 * Used during setup for glDraw/CopyPixels.
74 */
75 void
76 _swrast_span_default_fog( GLcontext *ctx, struct sw_span *span )
77 {
78 span->fog = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);
79 span->fogStep = span->dfogdx = span->dfogdy = 0.0F;
80 span->interpMask |= SPAN_FOG;
81 }
82
83
84 /**
85 * Init span's rgba or index interpolation values to the RasterPos color.
86 * Used during setup for glDraw/CopyPixels.
87 */
88 void
89 _swrast_span_default_color( GLcontext *ctx, struct sw_span *span )
90 {
91 if (ctx->Visual.rgbMode) {
92 GLchan r, g, b, a;
93 UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);
94 UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);
95 UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);
96 UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);
97 #if CHAN_TYPE == GL_FLOAT
98 span->red = r;
99 span->green = g;
100 span->blue = b;
101 span->alpha = a;
102 #else
103 span->red = IntToFixed(r);
104 span->green = IntToFixed(g);
105 span->blue = IntToFixed(b);
106 span->alpha = IntToFixed(a);
107 #endif
108 span->redStep = 0;
109 span->greenStep = 0;
110 span->blueStep = 0;
111 span->alphaStep = 0;
112 span->interpMask |= SPAN_RGBA;
113 }
114 else {
115 span->index = FloatToFixed(ctx->Current.RasterIndex);
116 span->indexStep = 0;
117 span->interpMask |= SPAN_INDEX;
118 }
119 }
120
121
122 /**
123 * Init span's texcoord interpolation values to the RasterPos texcoords.
124 * Used during setup for glDraw/CopyPixels.
125 */
126 void
127 _swrast_span_default_texcoords( GLcontext *ctx, struct sw_span *span )
128 {
129 GLuint i;
130 for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
131 const GLfloat *tc = ctx->Current.RasterTexCoords[i];
132 if (ctx->FragmentProgram._Enabled || ctx->ATIFragmentShader._Enabled) {
133 COPY_4V(span->tex[i], tc);
134 }
135 else if (tc[3] > 0.0F) {
136 /* use (s/q, t/q, r/q, 1) */
137 span->tex[i][0] = tc[0] / tc[3];
138 span->tex[i][1] = tc[1] / tc[3];
139 span->tex[i][2] = tc[2] / tc[3];
140 span->tex[i][3] = 1.0;
141 }
142 else {
143 ASSIGN_4V(span->tex[i], 0.0F, 0.0F, 0.0F, 1.0F);
144 }
145 ASSIGN_4V(span->texStepX[i], 0.0F, 0.0F, 0.0F, 0.0F);
146 ASSIGN_4V(span->texStepY[i], 0.0F, 0.0F, 0.0F, 0.0F);
147 }
148 span->interpMask |= SPAN_TEXTURE;
149 }
150
151
152 /* Fill in the span.color.rgba array from the interpolation values */
153 static void
154 interpolate_colors(GLcontext *ctx, struct sw_span *span)
155 {
156 const GLuint n = span->end;
157 GLchan (*rgba)[4] = span->array->rgba;
158 GLuint i;
159 (void) ctx;
160
161 ASSERT((span->interpMask & SPAN_RGBA) &&
162 !(span->arrayMask & SPAN_RGBA));
163
164 if (span->interpMask & SPAN_FLAT) {
165 /* constant color */
166 GLchan color[4];
167 color[RCOMP] = FixedToChan(span->red);
168 color[GCOMP] = FixedToChan(span->green);
169 color[BCOMP] = FixedToChan(span->blue);
170 color[ACOMP] = FixedToChan(span->alpha);
171 for (i = 0; i < n; i++) {
172 COPY_CHAN4(span->array->rgba[i], color);
173 }
174 }
175 else {
176 /* interpolate */
177 #if CHAN_TYPE == GL_FLOAT
178 GLfloat r = span->red;
179 GLfloat g = span->green;
180 GLfloat b = span->blue;
181 GLfloat a = span->alpha;
182 const GLfloat dr = span->redStep;
183 const GLfloat dg = span->greenStep;
184 const GLfloat db = span->blueStep;
185 const GLfloat da = span->alphaStep;
186 #else
187 GLfixed r = span->red;
188 GLfixed g = span->green;
189 GLfixed b = span->blue;
190 GLfixed a = span->alpha;
191 const GLint dr = span->redStep;
192 const GLint dg = span->greenStep;
193 const GLint db = span->blueStep;
194 const GLint da = span->alphaStep;
195 #endif
196 for (i = 0; i < n; i++) {
197 rgba[i][RCOMP] = FixedToChan(r);
198 rgba[i][GCOMP] = FixedToChan(g);
199 rgba[i][BCOMP] = FixedToChan(b);
200 rgba[i][ACOMP] = FixedToChan(a);
201 r += dr;
202 g += dg;
203 b += db;
204 a += da;
205 }
206 }
207 span->arrayMask |= SPAN_RGBA;
208 }
209
210
211 /* Fill in the span.color.index array from the interpolation values */
212 static void
213 interpolate_indexes(GLcontext *ctx, struct sw_span *span)
214 {
215 GLfixed index = span->index;
216 const GLint indexStep = span->indexStep;
217 const GLuint n = span->end;
218 GLuint *indexes = span->array->index;
219 GLuint i;
220 (void) ctx;
221 ASSERT((span->interpMask & SPAN_INDEX) &&
222 !(span->arrayMask & SPAN_INDEX));
223
224 if ((span->interpMask & SPAN_FLAT) || (indexStep == 0)) {
225 /* constant color */
226 index = FixedToInt(index);
227 for (i = 0; i < n; i++) {
228 indexes[i] = index;
229 }
230 }
231 else {
232 /* interpolate */
233 for (i = 0; i < n; i++) {
234 indexes[i] = FixedToInt(index);
235 index += indexStep;
236 }
237 }
238 span->arrayMask |= SPAN_INDEX;
239 span->interpMask &= ~SPAN_INDEX;
240 }
241
242
243 /* Fill in the span.->array->spec array from the interpolation values */
244 static void
245 interpolate_specular(GLcontext *ctx, struct sw_span *span)
246 {
247 (void) ctx;
248 if (span->interpMask & SPAN_FLAT) {
249 /* constant color */
250 const GLchan r = FixedToChan(span->specRed);
251 const GLchan g = FixedToChan(span->specGreen);
252 const GLchan b = FixedToChan(span->specBlue);
253 GLuint i;
254 for (i = 0; i < span->end; i++) {
255 span->array->spec[i][RCOMP] = r;
256 span->array->spec[i][GCOMP] = g;
257 span->array->spec[i][BCOMP] = b;
258 }
259 }
260 else {
261 /* interpolate */
262 #if CHAN_TYPE == GL_FLOAT
263 GLfloat r = span->specRed;
264 GLfloat g = span->specGreen;
265 GLfloat b = span->specBlue;
266 #else
267 GLfixed r = span->specRed;
268 GLfixed g = span->specGreen;
269 GLfixed b = span->specBlue;
270 #endif
271 GLuint i;
272 for (i = 0; i < span->end; i++) {
273 span->array->spec[i][RCOMP] = FixedToChan(r);
274 span->array->spec[i][GCOMP] = FixedToChan(g);
275 span->array->spec[i][BCOMP] = FixedToChan(b);
276 r += span->specRedStep;
277 g += span->specGreenStep;
278 b += span->specBlueStep;
279 }
280 }
281 span->arrayMask |= SPAN_SPEC;
282 }
283
284
285 /* Fill in the span.array.fog values from the interpolation values */
286 static void
287 interpolate_fog(const GLcontext *ctx, struct sw_span *span)
288 {
289 GLfloat *fog = span->array->fog;
290 const GLfloat fogStep = span->fogStep;
291 GLfloat fogCoord = span->fog;
292 const GLuint haveW = (span->interpMask & SPAN_W);
293 const GLfloat wStep = haveW ? span->dwdx : 0.0F;
294 GLfloat w = haveW ? span->w : 1.0F;
295 GLuint i;
296 for (i = 0; i < span->end; i++) {
297 fog[i] = fogCoord / w;
298 fogCoord += fogStep;
299 w += wStep;
300 }
301 span->arrayMask |= SPAN_FOG;
302 }
303
304
305 /* Fill in the span.zArray array from the interpolation values */
306 void
307 _swrast_span_interpolate_z( const GLcontext *ctx, struct sw_span *span )
308 {
309 const GLuint n = span->end;
310 GLuint i;
311
312 ASSERT((span->interpMask & SPAN_Z) &&
313 !(span->arrayMask & SPAN_Z));
314
315 if (ctx->DrawBuffer->Visual.depthBits <= 16) {
316 GLfixed zval = span->z;
317 GLuint *z = span->array->z;
318 for (i = 0; i < n; i++) {
319 z[i] = FixedToInt(zval);
320 zval += span->zStep;
321 }
322 }
323 else {
324 /* Deep Z buffer, no fixed->int shift */
325 GLuint zval = span->z;
326 GLuint *z = span->array->z;
327 for (i = 0; i < n; i++) {
328 z[i] = zval;
329 zval += span->zStep;
330 }
331 }
332 span->interpMask &= ~SPAN_Z;
333 span->arrayMask |= SPAN_Z;
334 }
335
336
337 /*
338 * This the ideal solution, as given in the OpenGL spec.
339 */
340 #if 0
341 static GLfloat
342 compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
343 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
344 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
345 {
346 GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);
347 GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);
348 GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);
349 GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);
350 GLfloat x = SQRTF(dudx * dudx + dvdx * dvdx);
351 GLfloat y = SQRTF(dudy * dudy + dvdy * dvdy);
352 GLfloat rho = MAX2(x, y);
353 GLfloat lambda = LOG2(rho);
354 return lambda;
355 }
356 #endif
357
358
359 /*
360 * This is a faster approximation
361 */
362 GLfloat
363 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
364 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
365 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
366 {
367 GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;
368 GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;
369 GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;
370 GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;
371 GLfloat maxU, maxV, rho, lambda;
372 dsdx2 = FABSF(dsdx2);
373 dsdy2 = FABSF(dsdy2);
374 dtdx2 = FABSF(dtdx2);
375 dtdy2 = FABSF(dtdy2);
376 maxU = MAX2(dsdx2, dsdy2) * texW;
377 maxV = MAX2(dtdx2, dtdy2) * texH;
378 rho = MAX2(maxU, maxV);
379 lambda = LOG2(rho);
380 return lambda;
381 }
382
383
384 /**
385 * Fill in the span.texcoords array from the interpolation values.
386 * Note: in the places where we divide by Q (or mult by invQ) we're
387 * really doing two things: perspective correction and texcoord
388 * projection. Remember, for texcoord (s,t,r,q) we need to index
389 * texels with (s/q, t/q, r/q).
390 * If we're using a fragment program, we never do the division
391 * for texcoord projection. That's done by the TXP instruction
392 * or user-written code.
393 */
394 static void
395 interpolate_texcoords(GLcontext *ctx, struct sw_span *span)
396 {
397 ASSERT(span->interpMask & SPAN_TEXTURE);
398 ASSERT(!(span->arrayMask & SPAN_TEXTURE));
399
400 if (ctx->Texture._EnabledCoordUnits > 1) {
401 /* multitexture */
402 GLuint u;
403 span->arrayMask |= SPAN_TEXTURE;
404 /* XXX CoordUnits vs. ImageUnits */
405 for (u = 0; u < ctx->Const.MaxTextureUnits; u++) {
406 if (ctx->Texture._EnabledCoordUnits & (1 << u)) {
407 const struct gl_texture_object *obj =ctx->Texture.Unit[u]._Current;
408 GLfloat texW, texH;
409 GLboolean needLambda;
410 if (obj) {
411 const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel];
412 needLambda = (obj->MinFilter != obj->MagFilter)
413 || ctx->FragmentProgram._Enabled;
414 texW = img->WidthScale;
415 texH = img->HeightScale;
416 }
417 else {
418 /* using a fragment program */
419 texW = 1.0;
420 texH = 1.0;
421 needLambda = GL_FALSE;
422 }
423 if (needLambda) {
424 GLfloat (*texcoord)[4] = span->array->texcoords[u];
425 GLfloat *lambda = span->array->lambda[u];
426 const GLfloat dsdx = span->texStepX[u][0];
427 const GLfloat dsdy = span->texStepY[u][0];
428 const GLfloat dtdx = span->texStepX[u][1];
429 const GLfloat dtdy = span->texStepY[u][1];
430 const GLfloat drdx = span->texStepX[u][2];
431 const GLfloat dqdx = span->texStepX[u][3];
432 const GLfloat dqdy = span->texStepY[u][3];
433 GLfloat s = span->tex[u][0];
434 GLfloat t = span->tex[u][1];
435 GLfloat r = span->tex[u][2];
436 GLfloat q = span->tex[u][3];
437 GLuint i;
438 if (ctx->FragmentProgram._Enabled || ctx->ATIFragmentShader._Enabled ||
439 ctx->ShaderObjects._FragmentShaderPresent) {
440 /* do perspective correction but don't divide s, t, r by q */
441 const GLfloat dwdx = span->dwdx;
442 GLfloat w = span->w;
443 for (i = 0; i < span->end; i++) {
444 const GLfloat invW = 1.0F / w;
445 texcoord[i][0] = s * invW;
446 texcoord[i][1] = t * invW;
447 texcoord[i][2] = r * invW;
448 texcoord[i][3] = q * invW;
449 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
450 dqdx, dqdy, texW, texH,
451 s, t, q, invW);
452 s += dsdx;
453 t += dtdx;
454 r += drdx;
455 q += dqdx;
456 w += dwdx;
457 }
458
459 }
460 else {
461 for (i = 0; i < span->end; i++) {
462 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
463 texcoord[i][0] = s * invQ;
464 texcoord[i][1] = t * invQ;
465 texcoord[i][2] = r * invQ;
466 texcoord[i][3] = q;
467 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
468 dqdx, dqdy, texW, texH,
469 s, t, q, invQ);
470 s += dsdx;
471 t += dtdx;
472 r += drdx;
473 q += dqdx;
474 }
475 }
476 span->arrayMask |= SPAN_LAMBDA;
477 }
478 else {
479 GLfloat (*texcoord)[4] = span->array->texcoords[u];
480 GLfloat *lambda = span->array->lambda[u];
481 const GLfloat dsdx = span->texStepX[u][0];
482 const GLfloat dtdx = span->texStepX[u][1];
483 const GLfloat drdx = span->texStepX[u][2];
484 const GLfloat dqdx = span->texStepX[u][3];
485 GLfloat s = span->tex[u][0];
486 GLfloat t = span->tex[u][1];
487 GLfloat r = span->tex[u][2];
488 GLfloat q = span->tex[u][3];
489 GLuint i;
490 if (ctx->FragmentProgram._Enabled || ctx->ATIFragmentShader._Enabled ||
491 ctx->ShaderObjects._FragmentShaderPresent) {
492 /* do perspective correction but don't divide s, t, r by q */
493 const GLfloat dwdx = span->dwdx;
494 GLfloat w = span->w;
495 for (i = 0; i < span->end; i++) {
496 const GLfloat invW = 1.0F / w;
497 texcoord[i][0] = s * invW;
498 texcoord[i][1] = t * invW;
499 texcoord[i][2] = r * invW;
500 texcoord[i][3] = q * invW;
501 lambda[i] = 0.0;
502 s += dsdx;
503 t += dtdx;
504 r += drdx;
505 q += dqdx;
506 w += dwdx;
507 }
508 }
509 else if (dqdx == 0.0F) {
510 /* Ortho projection or polygon's parallel to window X axis */
511 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
512 for (i = 0; i < span->end; i++) {
513 texcoord[i][0] = s * invQ;
514 texcoord[i][1] = t * invQ;
515 texcoord[i][2] = r * invQ;
516 texcoord[i][3] = q;
517 lambda[i] = 0.0;
518 s += dsdx;
519 t += dtdx;
520 r += drdx;
521 }
522 }
523 else {
524 for (i = 0; i < span->end; i++) {
525 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
526 texcoord[i][0] = s * invQ;
527 texcoord[i][1] = t * invQ;
528 texcoord[i][2] = r * invQ;
529 texcoord[i][3] = q;
530 lambda[i] = 0.0;
531 s += dsdx;
532 t += dtdx;
533 r += drdx;
534 q += dqdx;
535 }
536 }
537 } /* lambda */
538 } /* if */
539 } /* for */
540 }
541 else {
542 /* single texture */
543 const struct gl_texture_object *obj = ctx->Texture.Unit[0]._Current;
544 GLfloat texW, texH;
545 GLboolean needLambda;
546 if (obj) {
547 const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel];
548 needLambda = (obj->MinFilter != obj->MagFilter)
549 || ctx->FragmentProgram._Enabled;
550 texW = (GLfloat) img->WidthScale;
551 texH = (GLfloat) img->HeightScale;
552 }
553 else {
554 needLambda = GL_FALSE;
555 texW = texH = 1.0;
556 }
557 span->arrayMask |= SPAN_TEXTURE;
558 if (needLambda) {
559 /* just texture unit 0, with lambda */
560 GLfloat (*texcoord)[4] = span->array->texcoords[0];
561 GLfloat *lambda = span->array->lambda[0];
562 const GLfloat dsdx = span->texStepX[0][0];
563 const GLfloat dsdy = span->texStepY[0][0];
564 const GLfloat dtdx = span->texStepX[0][1];
565 const GLfloat dtdy = span->texStepY[0][1];
566 const GLfloat drdx = span->texStepX[0][2];
567 const GLfloat dqdx = span->texStepX[0][3];
568 const GLfloat dqdy = span->texStepY[0][3];
569 GLfloat s = span->tex[0][0];
570 GLfloat t = span->tex[0][1];
571 GLfloat r = span->tex[0][2];
572 GLfloat q = span->tex[0][3];
573 GLuint i;
574 if (ctx->FragmentProgram._Enabled || ctx->ATIFragmentShader._Enabled ||
575 ctx->ShaderObjects._FragmentShaderPresent) {
576 /* do perspective correction but don't divide s, t, r by q */
577 const GLfloat dwdx = span->dwdx;
578 GLfloat w = span->w;
579 for (i = 0; i < span->end; i++) {
580 const GLfloat invW = 1.0F / w;
581 texcoord[i][0] = s * invW;
582 texcoord[i][1] = t * invW;
583 texcoord[i][2] = r * invW;
584 texcoord[i][3] = q * invW;
585 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
586 dqdx, dqdy, texW, texH,
587 s, t, q, invW);
588 s += dsdx;
589 t += dtdx;
590 r += drdx;
591 q += dqdx;
592 w += dwdx;
593 }
594 }
595 else {
596 /* tex.c */
597 for (i = 0; i < span->end; i++) {
598 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
599 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
600 dqdx, dqdy, texW, texH,
601 s, t, q, invQ);
602 texcoord[i][0] = s * invQ;
603 texcoord[i][1] = t * invQ;
604 texcoord[i][2] = r * invQ;
605 texcoord[i][3] = q;
606 s += dsdx;
607 t += dtdx;
608 r += drdx;
609 q += dqdx;
610 }
611 }
612 span->arrayMask |= SPAN_LAMBDA;
613 }
614 else {
615 /* just texture 0, without lambda */
616 GLfloat (*texcoord)[4] = span->array->texcoords[0];
617 const GLfloat dsdx = span->texStepX[0][0];
618 const GLfloat dtdx = span->texStepX[0][1];
619 const GLfloat drdx = span->texStepX[0][2];
620 const GLfloat dqdx = span->texStepX[0][3];
621 GLfloat s = span->tex[0][0];
622 GLfloat t = span->tex[0][1];
623 GLfloat r = span->tex[0][2];
624 GLfloat q = span->tex[0][3];
625 GLuint i;
626 if (ctx->FragmentProgram._Enabled || ctx->ATIFragmentShader._Enabled ||
627 ctx->ShaderObjects._FragmentShaderPresent) {
628 /* do perspective correction but don't divide s, t, r by q */
629 const GLfloat dwdx = span->dwdx;
630 GLfloat w = span->w;
631 for (i = 0; i < span->end; i++) {
632 const GLfloat invW = 1.0F / w;
633 texcoord[i][0] = s * invW;
634 texcoord[i][1] = t * invW;
635 texcoord[i][2] = r * invW;
636 texcoord[i][3] = q * invW;
637 s += dsdx;
638 t += dtdx;
639 r += drdx;
640 q += dqdx;
641 w += dwdx;
642 }
643 }
644 else if (dqdx == 0.0F) {
645 /* Ortho projection or polygon's parallel to window X axis */
646 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
647 for (i = 0; i < span->end; i++) {
648 texcoord[i][0] = s * invQ;
649 texcoord[i][1] = t * invQ;
650 texcoord[i][2] = r * invQ;
651 texcoord[i][3] = q;
652 s += dsdx;
653 t += dtdx;
654 r += drdx;
655 }
656 }
657 else {
658 for (i = 0; i < span->end; i++) {
659 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
660 texcoord[i][0] = s * invQ;
661 texcoord[i][1] = t * invQ;
662 texcoord[i][2] = r * invQ;
663 texcoord[i][3] = q;
664 s += dsdx;
665 t += dtdx;
666 r += drdx;
667 q += dqdx;
668 }
669 }
670 }
671 }
672 }
673
674
675 /**
676 * Fill in the span.varying array from the interpolation values.
677 */
678 static void
679 interpolate_varying(GLcontext *ctx, struct sw_span *span)
680 {
681 GLuint i, j;
682
683 ASSERT(span->interpMask & SPAN_VARYING);
684 ASSERT(!(span->arrayMask & SPAN_VARYING));
685
686 span->arrayMask |= SPAN_VARYING;
687
688 for (i = 0; i < MAX_VARYING_VECTORS; i++) {
689 for (j = 0; j < VARYINGS_PER_VECTOR; j++) {
690 const GLfloat dvdx = span->varStepX[i][j];
691 GLfloat v = span->var[i][j];
692 const GLfloat dwdx = span->dwdx;
693 GLfloat w = span->w;
694 GLuint k;
695
696 for (k = 0; k < span->end; k++) {
697 GLfloat invW = 1.0f / w;
698 span->array->varying[k][i][j] = v * invW;
699 v += dvdx;
700 w += dwdx;
701 }
702 }
703 }
704 }
705
706
707 /**
708 * Apply the current polygon stipple pattern to a span of pixels.
709 */
710 static void
711 stipple_polygon_span( GLcontext *ctx, struct sw_span *span )
712 {
713 const GLuint highbit = 0x80000000;
714 const GLuint stipple = ctx->PolygonStipple[span->y % 32];
715 GLubyte *mask = span->array->mask;
716 GLuint i, m;
717
718 ASSERT(ctx->Polygon.StippleFlag);
719 ASSERT((span->arrayMask & SPAN_XY) == 0);
720
721 m = highbit >> (GLuint) (span->x % 32);
722
723 for (i = 0; i < span->end; i++) {
724 if ((m & stipple) == 0) {
725 mask[i] = 0;
726 }
727 m = m >> 1;
728 if (m == 0) {
729 m = highbit;
730 }
731 }
732 span->writeAll = GL_FALSE;
733 }
734
735
736 /**
737 * Clip a pixel span to the current buffer/window boundaries:
738 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
739 * window clipping and scissoring.
740 * Return: GL_TRUE some pixels still visible
741 * GL_FALSE nothing visible
742 */
743 static GLuint
744 clip_span( GLcontext *ctx, struct sw_span *span )
745 {
746 const GLint xmin = ctx->DrawBuffer->_Xmin;
747 const GLint xmax = ctx->DrawBuffer->_Xmax;
748 const GLint ymin = ctx->DrawBuffer->_Ymin;
749 const GLint ymax = ctx->DrawBuffer->_Ymax;
750
751 if (span->arrayMask & SPAN_XY) {
752 /* arrays of x/y pixel coords */
753 const GLint *x = span->array->x;
754 const GLint *y = span->array->y;
755 const GLint n = span->end;
756 GLubyte *mask = span->array->mask;
757 GLint i;
758 if (span->arrayMask & SPAN_MASK) {
759 /* note: using & intead of && to reduce branches */
760 for (i = 0; i < n; i++) {
761 mask[i] &= (x[i] >= xmin) & (x[i] < xmax)
762 & (y[i] >= ymin) & (y[i] < ymax);
763 }
764 }
765 else {
766 /* note: using & intead of && to reduce branches */
767 for (i = 0; i < n; i++) {
768 mask[i] = (x[i] >= xmin) & (x[i] < xmax)
769 & (y[i] >= ymin) & (y[i] < ymax);
770 }
771 }
772 return GL_TRUE; /* some pixels visible */
773 }
774 else {
775 /* horizontal span of pixels */
776 const GLint x = span->x;
777 const GLint y = span->y;
778 const GLint n = span->end;
779
780 /* Trivial rejection tests */
781 if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {
782 span->end = 0;
783 return GL_FALSE; /* all pixels clipped */
784 }
785
786 /* Clip to the left */
787 if (x < xmin) {
788 ASSERT(x + n > xmin);
789 span->writeAll = GL_FALSE;
790 _mesa_bzero(span->array->mask, (xmin - x) * sizeof(GLubyte));
791 }
792
793 /* Clip to right */
794 if (x + n > xmax) {
795 ASSERT(x < xmax);
796 span->end = xmax - x;
797 }
798
799 return GL_TRUE; /* some pixels visible */
800 }
801 }
802
803
804 /**
805 * Apply all the per-fragment opertions to a span of color index fragments
806 * and write them to the enabled color drawbuffers.
807 * The 'span' parameter can be considered to be const. Note that
808 * span->interpMask and span->arrayMask may be changed but will be restored
809 * to their original values before returning.
810 */
811 void
812 _swrast_write_index_span( GLcontext *ctx, struct sw_span *span)
813 {
814 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
815 const GLbitfield origInterpMask = span->interpMask;
816 const GLbitfield origArrayMask = span->arrayMask;
817
818 ASSERT(span->end <= MAX_WIDTH);
819 ASSERT(span->primitive == GL_POINT || span->primitive == GL_LINE ||
820 span->primitive == GL_POLYGON || span->primitive == GL_BITMAP);
821 ASSERT((span->interpMask | span->arrayMask) & SPAN_INDEX);
822 ASSERT((span->interpMask & span->arrayMask) == 0);
823
824 if (span->arrayMask & SPAN_MASK) {
825 /* mask was initialized by caller, probably glBitmap */
826 span->writeAll = GL_FALSE;
827 }
828 else {
829 _mesa_memset(span->array->mask, 1, span->end);
830 span->writeAll = GL_TRUE;
831 }
832
833 /* Clipping */
834 if ((swrast->_RasterMask & CLIP_BIT) || (span->primitive != GL_POLYGON)) {
835 if (!clip_span(ctx, span)) {
836 return;
837 }
838 }
839
840 /* Depth bounds test */
841 if (ctx->Depth.BoundsTest && ctx->DrawBuffer->Visual.depthBits > 0) {
842 if (!_swrast_depth_bounds_test(ctx, span)) {
843 return;
844 }
845 }
846
847 #ifdef DEBUG
848 /* Make sure all fragments are within window bounds */
849 if (span->arrayMask & SPAN_XY) {
850 GLuint i;
851 for (i = 0; i < span->end; i++) {
852 if (span->array->mask[i]) {
853 assert(span->array->x[i] >= ctx->DrawBuffer->_Xmin);
854 assert(span->array->x[i] < ctx->DrawBuffer->_Xmax);
855 assert(span->array->y[i] >= ctx->DrawBuffer->_Ymin);
856 assert(span->array->y[i] < ctx->DrawBuffer->_Ymax);
857 }
858 }
859 }
860 #endif
861
862 /* Polygon Stippling */
863 if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
864 stipple_polygon_span(ctx, span);
865 }
866
867 /* Stencil and Z testing */
868 if (ctx->Depth.Test || ctx->Stencil.Enabled) {
869 if (span->interpMask & SPAN_Z)
870 _swrast_span_interpolate_z(ctx, span);
871
872 if (ctx->Stencil.Enabled) {
873 if (!_swrast_stencil_and_ztest_span(ctx, span)) {
874 span->arrayMask = origArrayMask;
875 return;
876 }
877 }
878 else {
879 ASSERT(ctx->Depth.Test);
880 if (!_swrast_depth_test_span(ctx, span)) {
881 span->interpMask = origInterpMask;
882 span->arrayMask = origArrayMask;
883 return;
884 }
885 }
886 }
887
888 #if FEATURE_ARB_occlusion_query
889 if (ctx->Query.CurrentOcclusionObject) {
890 /* update count of 'passed' fragments */
891 struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
892 GLuint i;
893 for (i = 0; i < span->end; i++)
894 q->Result += span->array->mask[i];
895 }
896 #endif
897
898 /* we have to wait until after occlusion to do this test */
899 if (ctx->Color.DrawBuffer == GL_NONE || ctx->Color.IndexMask == 0) {
900 /* write no pixels */
901 span->arrayMask = origArrayMask;
902 return;
903 }
904
905 /* Interpolate the color indexes if needed */
906 if (swrast->_FogEnabled ||
907 ctx->Color.IndexLogicOpEnabled ||
908 ctx->Color.IndexMask != 0xffffffff ||
909 (span->arrayMask & SPAN_COVERAGE)) {
910 if (span->interpMask & SPAN_INDEX) {
911 interpolate_indexes(ctx, span);
912 }
913 }
914
915 /* Fog */
916 if (swrast->_FogEnabled) {
917 _swrast_fog_ci_span(ctx, span);
918 }
919
920 /* Antialias coverage application */
921 if (span->arrayMask & SPAN_COVERAGE) {
922 const GLfloat *coverage = span->array->coverage;
923 GLuint *index = span->array->index;
924 GLuint i;
925 for (i = 0; i < span->end; i++) {
926 ASSERT(coverage[i] < 16);
927 index[i] = (index[i] & ~0xf) | ((GLuint) coverage[i]);
928 }
929 }
930
931 /*
932 * Write to renderbuffers
933 */
934 {
935 struct gl_framebuffer *fb = ctx->DrawBuffer;
936 const GLuint output = 0; /* only frag progs can write to others */
937 const GLuint numDrawBuffers = fb->_NumColorDrawBuffers[output];
938 GLuint indexSave[MAX_WIDTH];
939 GLuint buf;
940
941 if (numDrawBuffers > 1) {
942 /* save indexes for second, third renderbuffer writes */
943 _mesa_memcpy(indexSave, span->array->index,
944 span->end * sizeof(indexSave[0]));
945 }
946
947 for (buf = 0; buf < fb->_NumColorDrawBuffers[output]; buf++) {
948 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[output][buf];
949 ASSERT(rb->_BaseFormat == GL_COLOR_INDEX);
950
951 if (ctx->Color.IndexLogicOpEnabled) {
952 _swrast_logicop_ci_span(ctx, rb, span, span->array->index);
953 }
954
955 if (ctx->Color.IndexMask != 0xffffffff) {
956 _swrast_mask_ci_span(ctx, rb, span, span->array->index);
957 }
958
959 if ((span->interpMask & SPAN_INDEX) && span->indexStep == 0) {
960 /* all fragments have same color index */
961 GLubyte index8;
962 GLushort index16;
963 GLuint index32;
964 void *value;
965
966 if (rb->DataType == GL_UNSIGNED_BYTE) {
967 index8 = FixedToInt(span->index);
968 value = &index8;
969 }
970 else if (rb->DataType == GL_UNSIGNED_SHORT) {
971 index16 = FixedToInt(span->index);
972 value = &index16;
973 }
974 else {
975 ASSERT(rb->DataType == GL_UNSIGNED_INT);
976 index32 = FixedToInt(span->index);
977 value = &index32;
978 }
979
980 if (span->arrayMask & SPAN_XY) {
981 rb->PutMonoValues(ctx, rb, span->end, span->array->x,
982 span->array->y, value, span->array->mask);
983 }
984 else {
985 rb->PutMonoRow(ctx, rb, span->end, span->x, span->y,
986 value, span->array->mask);
987 }
988 }
989 else {
990 /* each fragment is a different color */
991 GLubyte index8[MAX_WIDTH];
992 GLushort index16[MAX_WIDTH];
993 void *values;
994
995 if (rb->DataType == GL_UNSIGNED_BYTE) {
996 GLuint k;
997 for (k = 0; k < span->end; k++) {
998 index8[k] = (GLubyte) span->array->index[k];
999 }
1000 values = index8;
1001 }
1002 else if (rb->DataType == GL_UNSIGNED_SHORT) {
1003 GLuint k;
1004 for (k = 0; k < span->end; k++) {
1005 index16[k] = (GLushort) span->array->index[k];
1006 }
1007 values = index16;
1008 }
1009 else {
1010 ASSERT(rb->DataType == GL_UNSIGNED_INT);
1011 values = span->array->index;
1012 }
1013
1014 if (span->arrayMask & SPAN_XY) {
1015 rb->PutValues(ctx, rb, span->end,
1016 span->array->x, span->array->y,
1017 values, span->array->mask);
1018 }
1019 else {
1020 rb->PutRow(ctx, rb, span->end, span->x, span->y,
1021 values, span->array->mask);
1022 }
1023 }
1024
1025 if (buf + 1 < numDrawBuffers) {
1026 /* restore original span values */
1027 _mesa_memcpy(span->array->index, indexSave,
1028 span->end * sizeof(indexSave[0]));
1029 }
1030 } /* for buf */
1031 }
1032
1033 span->interpMask = origInterpMask;
1034 span->arrayMask = origArrayMask;
1035 }
1036
1037
1038 /**
1039 * Add specular color to base color. This is used only when
1040 * GL_LIGHT_MODEL_COLOR_CONTROL = GL_SEPARATE_SPECULAR_COLOR.
1041 */
1042 static void
1043 add_colors(GLuint n, GLchan rgba[][4], GLchan specular[][4] )
1044 {
1045 GLuint i;
1046 for (i = 0; i < n; i++) {
1047 #if CHAN_TYPE == GL_FLOAT
1048 /* no clamping */
1049 rgba[i][RCOMP] += specular[i][RCOMP];
1050 rgba[i][GCOMP] += specular[i][GCOMP];
1051 rgba[i][BCOMP] += specular[i][BCOMP];
1052 #else
1053 GLint r = rgba[i][RCOMP] + specular[i][RCOMP];
1054 GLint g = rgba[i][GCOMP] + specular[i][GCOMP];
1055 GLint b = rgba[i][BCOMP] + specular[i][BCOMP];
1056 rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
1057 rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
1058 rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
1059 #endif
1060 }
1061 }
1062
1063
1064 /**
1065 * Apply all the per-fragment operations to a span.
1066 * This now includes texturing (_swrast_write_texture_span() is history).
1067 * This function may modify any of the array values in the span.
1068 * span->interpMask and span->arrayMask may be changed but will be restored
1069 * to their original values before returning.
1070 */
1071 void
1072 _swrast_write_rgba_span( GLcontext *ctx, struct sw_span *span)
1073 {
1074 const GLuint colorMask = *((GLuint *) ctx->Color.ColorMask);
1075 SWcontext *swrast = SWRAST_CONTEXT(ctx);
1076 const GLbitfield origInterpMask = span->interpMask;
1077 const GLbitfield origArrayMask = span->arrayMask;
1078 const GLboolean deferredTexture = !(ctx->Color.AlphaEnabled ||
1079 ctx->FragmentProgram._Enabled ||
1080 ctx->ShaderObjects._FragmentShaderPresent);
1081
1082 ASSERT(span->primitive == GL_POINT || span->primitive == GL_LINE ||
1083 span->primitive == GL_POLYGON || span->primitive == GL_BITMAP);
1084 ASSERT(span->end <= MAX_WIDTH);
1085 ASSERT((span->interpMask & span->arrayMask) == 0);
1086
1087 /*
1088 printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__,
1089 span->interpMask, span->arrayMask);
1090 */
1091
1092 if (span->arrayMask & SPAN_MASK) {
1093 /* mask was initialized by caller, probably glBitmap */
1094 span->writeAll = GL_FALSE;
1095 }
1096 else {
1097 _mesa_memset(span->array->mask, 1, span->end);
1098 span->writeAll = GL_TRUE;
1099 }
1100
1101 /* Clip to window/scissor box */
1102 if ((swrast->_RasterMask & CLIP_BIT) || (span->primitive != GL_POLYGON)) {
1103 if (!clip_span(ctx, span)) {
1104 return;
1105 }
1106 }
1107
1108 #ifdef DEBUG
1109 /* Make sure all fragments are within window bounds */
1110 if (span->arrayMask & SPAN_XY) {
1111 GLuint i;
1112 for (i = 0; i < span->end; i++) {
1113 if (span->array->mask[i]) {
1114 assert(span->array->x[i] >= ctx->DrawBuffer->_Xmin);
1115 assert(span->array->x[i] < ctx->DrawBuffer->_Xmax);
1116 assert(span->array->y[i] >= ctx->DrawBuffer->_Ymin);
1117 assert(span->array->y[i] < ctx->DrawBuffer->_Ymax);
1118 }
1119 }
1120 }
1121 #endif
1122
1123 /* Polygon Stippling */
1124 if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
1125 stipple_polygon_span(ctx, span);
1126 }
1127
1128 /* Interpolate texcoords? */
1129 if (ctx->Texture._EnabledCoordUnits
1130 && (span->interpMask & SPAN_TEXTURE)
1131 && (span->arrayMask & SPAN_TEXTURE) == 0) {
1132 interpolate_texcoords(ctx, span);
1133 }
1134
1135 if (ctx->ShaderObjects._FragmentShaderPresent) {
1136 interpolate_varying(ctx, span);
1137 }
1138
1139 /* This is the normal place to compute the resulting fragment color/Z.
1140 * As an optimization, we try to defer this until after Z/stencil
1141 * testing in order to try to avoid computing colors that we won't
1142 * actually need.
1143 */
1144 if (!deferredTexture) {
1145 /* Now we need the rgba array, fill it in if needed */
1146 if ((span->interpMask & SPAN_RGBA) && (span->arrayMask & SPAN_RGBA) == 0)
1147 interpolate_colors(ctx, span);
1148
1149 if (span->interpMask & SPAN_SPEC)
1150 interpolate_specular(ctx, span);
1151
1152 if (span->interpMask & SPAN_FOG)
1153 interpolate_fog(ctx, span);
1154
1155 /* Compute fragment colors with fragment program or texture lookups */
1156 #if FEATURE_ARB_fragment_shader
1157 if (ctx->ShaderObjects._FragmentShaderPresent) {
1158 if (span->interpMask & SPAN_Z)
1159 _swrast_span_interpolate_z (ctx, span);
1160 _swrast_exec_arbshader (ctx, span);
1161 }
1162 else
1163 #endif
1164 if (ctx->FragmentProgram._Enabled) {
1165 /* frag prog may need Z values */
1166 if (span->interpMask & SPAN_Z)
1167 _swrast_span_interpolate_z(ctx, span);
1168 _swrast_exec_fragment_program( ctx, span );
1169 }
1170 else if (ctx->ATIFragmentShader._Enabled)
1171 _swrast_exec_fragment_shader( ctx, span );
1172 else if (ctx->Texture._EnabledUnits && (span->arrayMask & SPAN_TEXTURE))
1173 _swrast_texture_span( ctx, span );
1174
1175 /* Do the alpha test */
1176 if (ctx->Color.AlphaEnabled) {
1177 if (!_swrast_alpha_test(ctx, span)) {
1178 span->arrayMask = origArrayMask;
1179 return;
1180 }
1181 }
1182 }
1183
1184 /* Stencil and Z testing */
1185 if (ctx->Stencil.Enabled || ctx->Depth.Test) {
1186 if (span->interpMask & SPAN_Z)
1187 _swrast_span_interpolate_z(ctx, span);
1188
1189 if (ctx->Stencil.Enabled && ctx->DrawBuffer->Visual.stencilBits > 0) {
1190 /* Combined Z/stencil tests */
1191 if (!_swrast_stencil_and_ztest_span(ctx, span)) {
1192 span->interpMask = origInterpMask;
1193 span->arrayMask = origArrayMask;
1194 return;
1195 }
1196 }
1197 else if (ctx->DrawBuffer->Visual.depthBits > 0) {
1198 /* Just regular depth testing */
1199 ASSERT(ctx->Depth.Test);
1200 ASSERT(span->arrayMask & SPAN_Z);
1201 if (!_swrast_depth_test_span(ctx, span)) {
1202 span->interpMask = origInterpMask;
1203 span->arrayMask = origArrayMask;
1204 return;
1205 }
1206 }
1207 }
1208
1209 #if FEATURE_ARB_occlusion_query
1210 if (ctx->Query.CurrentOcclusionObject) {
1211 /* update count of 'passed' fragments */
1212 struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
1213 GLuint i;
1214 for (i = 0; i < span->end; i++)
1215 q->Result += span->array->mask[i];
1216 }
1217 #endif
1218
1219 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1220 * the occlusion test.
1221 */
1222 if (colorMask == 0x0) {
1223 span->interpMask = origInterpMask;
1224 span->arrayMask = origArrayMask;
1225 return;
1226 }
1227
1228 /* If we were able to defer fragment color computation to now, there's
1229 * a good chance that many fragments will have already been killed by
1230 * Z/stencil testing.
1231 */
1232 if (deferredTexture) {
1233 /* Now we need the rgba array, fill it in if needed */
1234 if ((span->interpMask & SPAN_RGBA) && (span->arrayMask & SPAN_RGBA) == 0)
1235 interpolate_colors(ctx, span);
1236
1237 if (span->interpMask & SPAN_SPEC)
1238 interpolate_specular(ctx, span);
1239
1240 if (span->interpMask & SPAN_FOG)
1241 interpolate_fog(ctx, span);
1242
1243 #if FEATURE_ARB_fragment_shader
1244 if (ctx->ShaderObjects._FragmentShaderPresent) {
1245 if (span->interpMask & SPAN_Z)
1246 _swrast_span_interpolate_z (ctx, span);
1247 _swrast_exec_arbshader (ctx, span);
1248 }
1249 else
1250 #endif
1251 if (ctx->FragmentProgram._Enabled)
1252 _swrast_exec_fragment_program( ctx, span );
1253 else if (ctx->ATIFragmentShader._Enabled)
1254 _swrast_exec_fragment_shader( ctx, span );
1255 else if (ctx->Texture._EnabledUnits && (span->arrayMask & SPAN_TEXTURE))
1256 _swrast_texture_span( ctx, span );
1257 }
1258
1259 ASSERT(span->arrayMask & SPAN_RGBA);
1260
1261 if (!ctx->FragmentProgram._Enabled) {
1262 /* Add base and specular colors */
1263 if (ctx->Fog.ColorSumEnabled ||
1264 (ctx->Light.Enabled &&
1265 ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {
1266 if (span->interpMask & SPAN_SPEC) {
1267 interpolate_specular(ctx, span);
1268 }
1269 if (span->arrayMask & SPAN_SPEC) {
1270 add_colors( span->end, span->array->rgba, span->array->spec );
1271 }
1272 else {
1273 /* We probably added the base/specular colors during the
1274 * vertex stage!
1275 */
1276 }
1277 }
1278 }
1279
1280 /* Fog */
1281 if (swrast->_FogEnabled) {
1282 _swrast_fog_rgba_span(ctx, span);
1283 }
1284
1285 /* Antialias coverage application */
1286 if (span->arrayMask & SPAN_COVERAGE) {
1287 GLchan (*rgba)[4] = span->array->rgba;
1288 GLfloat *coverage = span->array->coverage;
1289 GLuint i;
1290 for (i = 0; i < span->end; i++) {
1291 rgba[i][ACOMP] = (GLchan) (rgba[i][ACOMP] * coverage[i]);
1292 }
1293 }
1294
1295 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1296 #if CHAN_TYPE == GL_FLOAT
1297 if (ctx->Color.ClampFragmentColor) {
1298 GLchan (*rgba)[4] = span->array->rgba;
1299 GLuint i;
1300 for (i = 0; i < span->end; i++) {
1301 rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0, CHAN_MAXF);
1302 rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0, CHAN_MAXF);
1303 rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0, CHAN_MAXF);
1304 rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0, CHAN_MAXF);
1305 }
1306 }
1307 #endif
1308
1309 /*
1310 * Write to renderbuffers
1311 */
1312 {
1313 struct gl_framebuffer *fb = ctx->DrawBuffer;
1314 const GLuint output = 0; /* only frag progs can write to others */
1315 const GLuint numDrawBuffers = fb->_NumColorDrawBuffers[output];
1316 GLchan rgbaSave[MAX_WIDTH][4];
1317 GLuint buf;
1318
1319 if (numDrawBuffers > 1) {
1320 /* save colors for second, third renderbuffer writes */
1321 _mesa_memcpy(rgbaSave, span->array->rgba,
1322 4 * span->end * sizeof(GLchan));
1323 }
1324
1325 for (buf = 0; buf < numDrawBuffers; buf++) {
1326 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[output][buf];
1327 ASSERT(rb->_BaseFormat == GL_RGBA);
1328
1329 if (ctx->Color._LogicOpEnabled) {
1330 _swrast_logicop_rgba_span(ctx, rb, span, span->array->rgba);
1331 }
1332 else if (ctx->Color.BlendEnabled) {
1333 _swrast_blend_span(ctx, rb, span, span->array->rgba);
1334 }
1335
1336 if (colorMask != 0xffffffff) {
1337 _swrast_mask_rgba_span(ctx, rb, span, span->array->rgba);
1338 }
1339
1340 if (span->arrayMask & SPAN_XY) {
1341 /* array of pixel coords */
1342 ASSERT(rb->PutValues);
1343 ASSERT(rb->_BaseFormat == GL_RGB || rb->_BaseFormat == GL_RGBA);
1344 rb->PutValues(ctx, rb, span->end,
1345 span->array->x, span->array->y,
1346 span->array->rgba, span->array->mask);
1347 }
1348 else {
1349 /* horizontal run of pixels */
1350 ASSERT(rb->PutRow);
1351 ASSERT(rb->_BaseFormat == GL_RGB || rb->_BaseFormat == GL_RGBA);
1352 rb->PutRow(ctx, rb, span->end, span->x, span->y, span->array->rgba,
1353 span->writeAll ? NULL: span->array->mask);
1354 }
1355
1356 if (buf + 1 < numDrawBuffers) {
1357 /* restore original span values */
1358 _mesa_memcpy(span->array->rgba, rgbaSave,
1359 4 * span->end * sizeof(GLchan));
1360 }
1361 } /* for buf */
1362 }
1363
1364 span->interpMask = origInterpMask;
1365 span->arrayMask = origArrayMask;
1366 }
1367
1368
1369
1370 /**
1371 * Read RGBA pixels from frame buffer. Clipping will be done to prevent
1372 * reading ouside the buffer's boundaries.
1373 */
1374 void
1375 _swrast_read_rgba_span( GLcontext *ctx, struct gl_renderbuffer *rb,
1376 GLuint n, GLint x, GLint y, GLchan rgba[][4] )
1377 {
1378 const GLint bufWidth = (GLint) rb->Width;
1379 const GLint bufHeight = (GLint) rb->Height;
1380
1381 if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
1382 /* completely above, below, or right */
1383 /* XXX maybe leave rgba values undefined? */
1384 _mesa_bzero(rgba, 4 * n * sizeof(GLchan));
1385 }
1386 else {
1387 GLint skip, length;
1388 if (x < 0) {
1389 /* left edge clipping */
1390 skip = -x;
1391 length = (GLint) n - skip;
1392 if (length < 0) {
1393 /* completely left of window */
1394 return;
1395 }
1396 if (length > bufWidth) {
1397 length = bufWidth;
1398 }
1399 }
1400 else if ((GLint) (x + n) > bufWidth) {
1401 /* right edge clipping */
1402 skip = 0;
1403 length = bufWidth - x;
1404 if (length < 0) {
1405 /* completely to right of window */
1406 return;
1407 }
1408 }
1409 else {
1410 /* no clipping */
1411 skip = 0;
1412 length = (GLint) n;
1413 }
1414
1415 ASSERT(rb);
1416 ASSERT(rb->GetRow);
1417 ASSERT(rb->_BaseFormat == GL_RGB || rb->_BaseFormat == GL_RGBA);
1418 ASSERT(rb->DataType == CHAN_TYPE);
1419 rb->GetRow(ctx, rb, length, x + skip, y, rgba + skip);
1420 }
1421 }
1422
1423
1424 /**
1425 * Read CI pixels from frame buffer. Clipping will be done to prevent
1426 * reading ouside the buffer's boundaries.
1427 */
1428 void
1429 _swrast_read_index_span( GLcontext *ctx, struct gl_renderbuffer *rb,
1430 GLuint n, GLint x, GLint y, GLuint index[] )
1431 {
1432 const GLint bufWidth = (GLint) rb->Width;
1433 const GLint bufHeight = (GLint) rb->Height;
1434
1435 if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
1436 /* completely above, below, or right */
1437 _mesa_bzero(index, n * sizeof(GLuint));
1438 }
1439 else {
1440 GLint skip, length;
1441 if (x < 0) {
1442 /* left edge clipping */
1443 skip = -x;
1444 length = (GLint) n - skip;
1445 if (length < 0) {
1446 /* completely left of window */
1447 return;
1448 }
1449 if (length > bufWidth) {
1450 length = bufWidth;
1451 }
1452 }
1453 else if ((GLint) (x + n) > bufWidth) {
1454 /* right edge clipping */
1455 skip = 0;
1456 length = bufWidth - x;
1457 if (length < 0) {
1458 /* completely to right of window */
1459 return;
1460 }
1461 }
1462 else {
1463 /* no clipping */
1464 skip = 0;
1465 length = (GLint) n;
1466 }
1467
1468 ASSERT(rb->GetRow);
1469 ASSERT(rb->_BaseFormat == GL_COLOR_INDEX);
1470
1471 if (rb->DataType == GL_UNSIGNED_BYTE) {
1472 GLubyte index8[MAX_WIDTH];
1473 GLint i;
1474 rb->GetRow(ctx, rb, length, x + skip, y, index8);
1475 for (i = 0; i < length; i++)
1476 index[skip + i] = index8[i];
1477 }
1478 else if (rb->DataType == GL_UNSIGNED_SHORT) {
1479 GLushort index16[MAX_WIDTH];
1480 GLint i;
1481 rb->GetRow(ctx, rb, length, x + skip, y, index16);
1482 for (i = 0; i < length; i++)
1483 index[skip + i] = index16[i];
1484 }
1485 else if (rb->DataType == GL_UNSIGNED_INT) {
1486 rb->GetRow(ctx, rb, length, x + skip, y, index + skip);
1487 }
1488 }
1489 }
1490
1491
1492 /**
1493 * Wrapper for gl_renderbuffer::GetValues() which does clipping to avoid
1494 * reading values outside the buffer bounds.
1495 * We can use this for reading any format/type of renderbuffer.
1496 * \param valueSize is the size in bytes of each value (pixel) put into the
1497 * values array.
1498 */
1499 void
1500 _swrast_get_values(GLcontext *ctx, struct gl_renderbuffer *rb,
1501 GLuint count, const GLint x[], const GLint y[],
1502 void *values, GLuint valueSize)
1503 {
1504 GLuint i, inCount = 0, inStart = 0;
1505
1506 for (i = 0; i < count; i++) {
1507 if (x[i] >= 0 && y[i] >= 0 && x[i] < rb->Width && y[i] < rb->Height) {
1508 /* inside */
1509 if (inCount == 0)
1510 inStart = i;
1511 inCount++;
1512 }
1513 else {
1514 if (inCount > 0) {
1515 /* read [inStart, inStart + inCount) */
1516 rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,
1517 (GLubyte *) values + inStart * valueSize);
1518 inCount = 0;
1519 }
1520 }
1521 }
1522 if (inCount > 0) {
1523 /* read last values */
1524 rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,
1525 (GLubyte *) values + inStart * valueSize);
1526 }
1527 }
1528
1529
1530 /**
1531 * Wrapper for gl_renderbuffer::PutRow() which does clipping.
1532 */
1533 void
1534 _swrast_put_row(GLcontext *ctx, struct gl_renderbuffer *rb,
1535 GLuint count, GLint x, GLint y,
1536 const GLvoid *values, GLuint valueSize)
1537 {
1538 GLint skip = 0;
1539
1540 if (y < 0 || y >= rb->Height)
1541 return; /* above or below */
1542
1543 if (x + (GLint) count <= 0 || x >= rb->Width)
1544 return; /* entirely left or right */
1545
1546 if (x + count > rb->Width) {
1547 /* right clip */
1548 GLint clip = x + count - rb->Width;
1549 count -= clip;
1550 }
1551
1552 if (x < 0) {
1553 /* left clip */
1554 skip = -x;
1555 x = 0;
1556 count -= skip;
1557 }
1558
1559 rb->PutRow(ctx, rb, count, x, y,
1560 (const GLubyte *) values + skip * valueSize, NULL);
1561 }
1562
1563
1564 /**
1565 * Wrapper for gl_renderbuffer::GetRow() which does clipping.
1566 */
1567 void
1568 _swrast_get_row(GLcontext *ctx, struct gl_renderbuffer *rb,
1569 GLuint count, GLint x, GLint y,
1570 GLvoid *values, GLuint valueSize)
1571 {
1572 GLint skip = 0;
1573
1574 if (y < 0 || y >= rb->Height)
1575 return; /* above or below */
1576
1577 if (x + (GLint) count <= 0 || x >= rb->Width)
1578 return; /* entirely left or right */
1579
1580 if (x + count > rb->Width) {
1581 /* right clip */
1582 GLint clip = x + count - rb->Width;
1583 count -= clip;
1584 }
1585
1586 if (x < 0) {
1587 /* left clip */
1588 skip = -x;
1589 x = 0;
1590 count -= skip;
1591 }
1592
1593 rb->GetRow(ctx, rb, count, x, y, (GLubyte *) values + skip * valueSize);
1594 }