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swrast: fix multiple color buffer writing
[mesa.git] / src / mesa / swrast / s_span.c
1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
5 * Copyright (C) 2009 VMware, Inc. 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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 * OTHER DEALINGS IN THE SOFTWARE.
24 */
25
26
27 /**
28 * \file swrast/s_span.c
29 * \brief Span processing functions used by all rasterization functions.
30 * This is where all the per-fragment tests are performed
31 * \author Brian Paul
32 */
33
34 #include "main/glheader.h"
35 #include "main/colormac.h"
36 #include "main/format_pack.h"
37 #include "main/format_unpack.h"
38 #include "main/macros.h"
39 #include "main/imports.h"
40 #include "main/image.h"
41 #include "main/samplerobj.h"
42 #include "main/teximage.h"
43
44 #include "s_atifragshader.h"
45 #include "s_alpha.h"
46 #include "s_blend.h"
47 #include "s_context.h"
48 #include "s_depth.h"
49 #include "s_fog.h"
50 #include "s_logic.h"
51 #include "s_masking.h"
52 #include "s_fragprog.h"
53 #include "s_span.h"
54 #include "s_stencil.h"
55 #include "s_texcombine.h"
56
57 #include <stdbool.h>
58
59 /**
60 * Set default fragment attributes for the span using the
61 * current raster values. Used prior to glDraw/CopyPixels
62 * and glBitmap.
63 */
64 void
65 _swrast_span_default_attribs(struct gl_context *ctx, SWspan *span)
66 {
67 GLchan r, g, b, a;
68 /* Z*/
69 {
70 const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;
71 if (ctx->DrawBuffer->Visual.depthBits <= 16)
72 span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);
73 else {
74 GLfloat tmpf = ctx->Current.RasterPos[2] * depthMax;
75 tmpf = MIN2(tmpf, depthMax);
76 span->z = (GLint)tmpf;
77 }
78 span->zStep = 0;
79 span->interpMask |= SPAN_Z;
80 }
81
82 /* W (for perspective correction) */
83 span->attrStart[VARYING_SLOT_POS][3] = 1.0;
84 span->attrStepX[VARYING_SLOT_POS][3] = 0.0;
85 span->attrStepY[VARYING_SLOT_POS][3] = 0.0;
86
87 /* primary color, or color index */
88 UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);
89 UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);
90 UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);
91 UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);
92 #if CHAN_TYPE == GL_FLOAT
93 span->red = r;
94 span->green = g;
95 span->blue = b;
96 span->alpha = a;
97 #else
98 span->red = IntToFixed(r);
99 span->green = IntToFixed(g);
100 span->blue = IntToFixed(b);
101 span->alpha = IntToFixed(a);
102 #endif
103 span->redStep = 0;
104 span->greenStep = 0;
105 span->blueStep = 0;
106 span->alphaStep = 0;
107 span->interpMask |= SPAN_RGBA;
108
109 COPY_4V(span->attrStart[VARYING_SLOT_COL0], ctx->Current.RasterColor);
110 ASSIGN_4V(span->attrStepX[VARYING_SLOT_COL0], 0.0, 0.0, 0.0, 0.0);
111 ASSIGN_4V(span->attrStepY[VARYING_SLOT_COL0], 0.0, 0.0, 0.0, 0.0);
112
113 /* Secondary color */
114 if (ctx->Light.Enabled || ctx->Fog.ColorSumEnabled)
115 {
116 COPY_4V(span->attrStart[VARYING_SLOT_COL1], ctx->Current.RasterSecondaryColor);
117 ASSIGN_4V(span->attrStepX[VARYING_SLOT_COL1], 0.0, 0.0, 0.0, 0.0);
118 ASSIGN_4V(span->attrStepY[VARYING_SLOT_COL1], 0.0, 0.0, 0.0, 0.0);
119 }
120
121 /* fog */
122 {
123 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
124 GLfloat fogVal; /* a coord or a blend factor */
125 if (swrast->_PreferPixelFog) {
126 /* fog blend factors will be computed from fog coordinates per pixel */
127 fogVal = ctx->Current.RasterDistance;
128 }
129 else {
130 /* fog blend factor should be computed from fogcoord now */
131 fogVal = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);
132 }
133 span->attrStart[VARYING_SLOT_FOGC][0] = fogVal;
134 span->attrStepX[VARYING_SLOT_FOGC][0] = 0.0;
135 span->attrStepY[VARYING_SLOT_FOGC][0] = 0.0;
136 }
137
138 /* texcoords */
139 {
140 GLuint i;
141 for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
142 const GLuint attr = VARYING_SLOT_TEX0 + i;
143 const GLfloat *tc = ctx->Current.RasterTexCoords[i];
144 if (_swrast_use_fragment_program(ctx) ||
145 ctx->ATIFragmentShader._Enabled) {
146 COPY_4V(span->attrStart[attr], tc);
147 }
148 else if (tc[3] > 0.0F) {
149 /* use (s/q, t/q, r/q, 1) */
150 span->attrStart[attr][0] = tc[0] / tc[3];
151 span->attrStart[attr][1] = tc[1] / tc[3];
152 span->attrStart[attr][2] = tc[2] / tc[3];
153 span->attrStart[attr][3] = 1.0;
154 }
155 else {
156 ASSIGN_4V(span->attrStart[attr], 0.0F, 0.0F, 0.0F, 1.0F);
157 }
158 ASSIGN_4V(span->attrStepX[attr], 0.0F, 0.0F, 0.0F, 0.0F);
159 ASSIGN_4V(span->attrStepY[attr], 0.0F, 0.0F, 0.0F, 0.0F);
160 }
161 }
162 }
163
164
165 /**
166 * Interpolate the active attributes (and'd with attrMask) to
167 * fill in span->array->attribs[].
168 * Perspective correction will be done. The point/line/triangle function
169 * should have computed attrStart/Step values for VARYING_SLOT_POS[3]!
170 */
171 static inline void
172 interpolate_active_attribs(struct gl_context *ctx, SWspan *span,
173 GLbitfield64 attrMask)
174 {
175 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
176
177 /*
178 * Don't overwrite existing array values, such as colors that may have
179 * been produced by glDraw/CopyPixels.
180 */
181 attrMask &= ~span->arrayAttribs;
182
183 ATTRIB_LOOP_BEGIN
184 if (attrMask & BITFIELD64_BIT(attr)) {
185 const GLfloat dwdx = span->attrStepX[VARYING_SLOT_POS][3];
186 GLfloat w = span->attrStart[VARYING_SLOT_POS][3];
187 const GLfloat dv0dx = span->attrStepX[attr][0];
188 const GLfloat dv1dx = span->attrStepX[attr][1];
189 const GLfloat dv2dx = span->attrStepX[attr][2];
190 const GLfloat dv3dx = span->attrStepX[attr][3];
191 GLfloat v0 = span->attrStart[attr][0] + span->leftClip * dv0dx;
192 GLfloat v1 = span->attrStart[attr][1] + span->leftClip * dv1dx;
193 GLfloat v2 = span->attrStart[attr][2] + span->leftClip * dv2dx;
194 GLfloat v3 = span->attrStart[attr][3] + span->leftClip * dv3dx;
195 GLuint k;
196 for (k = 0; k < span->end; k++) {
197 const GLfloat invW = 1.0f / w;
198 span->array->attribs[attr][k][0] = v0 * invW;
199 span->array->attribs[attr][k][1] = v1 * invW;
200 span->array->attribs[attr][k][2] = v2 * invW;
201 span->array->attribs[attr][k][3] = v3 * invW;
202 v0 += dv0dx;
203 v1 += dv1dx;
204 v2 += dv2dx;
205 v3 += dv3dx;
206 w += dwdx;
207 }
208 ASSERT((span->arrayAttribs & BITFIELD64_BIT(attr)) == 0);
209 span->arrayAttribs |= BITFIELD64_BIT(attr);
210 }
211 ATTRIB_LOOP_END
212 }
213
214
215 /**
216 * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
217 * color array.
218 */
219 static inline void
220 interpolate_int_colors(struct gl_context *ctx, SWspan *span)
221 {
222 #if CHAN_BITS != 32
223 const GLuint n = span->end;
224 GLuint i;
225
226 ASSERT(!(span->arrayMask & SPAN_RGBA));
227 #endif
228
229 switch (span->array->ChanType) {
230 #if CHAN_BITS != 32
231 case GL_UNSIGNED_BYTE:
232 {
233 GLubyte (*rgba)[4] = span->array->rgba8;
234 if (span->interpMask & SPAN_FLAT) {
235 GLubyte color[4];
236 color[RCOMP] = FixedToInt(span->red);
237 color[GCOMP] = FixedToInt(span->green);
238 color[BCOMP] = FixedToInt(span->blue);
239 color[ACOMP] = FixedToInt(span->alpha);
240 for (i = 0; i < n; i++) {
241 COPY_4UBV(rgba[i], color);
242 }
243 }
244 else {
245 GLfixed r = span->red;
246 GLfixed g = span->green;
247 GLfixed b = span->blue;
248 GLfixed a = span->alpha;
249 GLint dr = span->redStep;
250 GLint dg = span->greenStep;
251 GLint db = span->blueStep;
252 GLint da = span->alphaStep;
253 for (i = 0; i < n; i++) {
254 rgba[i][RCOMP] = FixedToChan(r);
255 rgba[i][GCOMP] = FixedToChan(g);
256 rgba[i][BCOMP] = FixedToChan(b);
257 rgba[i][ACOMP] = FixedToChan(a);
258 r += dr;
259 g += dg;
260 b += db;
261 a += da;
262 }
263 }
264 }
265 break;
266 case GL_UNSIGNED_SHORT:
267 {
268 GLushort (*rgba)[4] = span->array->rgba16;
269 if (span->interpMask & SPAN_FLAT) {
270 GLushort color[4];
271 color[RCOMP] = FixedToInt(span->red);
272 color[GCOMP] = FixedToInt(span->green);
273 color[BCOMP] = FixedToInt(span->blue);
274 color[ACOMP] = FixedToInt(span->alpha);
275 for (i = 0; i < n; i++) {
276 COPY_4V(rgba[i], color);
277 }
278 }
279 else {
280 GLushort (*rgba)[4] = span->array->rgba16;
281 GLfixed r, g, b, a;
282 GLint dr, dg, db, da;
283 r = span->red;
284 g = span->green;
285 b = span->blue;
286 a = span->alpha;
287 dr = span->redStep;
288 dg = span->greenStep;
289 db = span->blueStep;
290 da = span->alphaStep;
291 for (i = 0; i < n; i++) {
292 rgba[i][RCOMP] = FixedToChan(r);
293 rgba[i][GCOMP] = FixedToChan(g);
294 rgba[i][BCOMP] = FixedToChan(b);
295 rgba[i][ACOMP] = FixedToChan(a);
296 r += dr;
297 g += dg;
298 b += db;
299 a += da;
300 }
301 }
302 }
303 break;
304 #endif
305 case GL_FLOAT:
306 interpolate_active_attribs(ctx, span, VARYING_BIT_COL0);
307 break;
308 default:
309 _mesa_problem(ctx, "bad datatype 0x%x in interpolate_int_colors",
310 span->array->ChanType);
311 }
312 span->arrayMask |= SPAN_RGBA;
313 }
314
315
316 /**
317 * Populate the VARYING_SLOT_COL0 array.
318 */
319 static inline void
320 interpolate_float_colors(SWspan *span)
321 {
322 GLfloat (*col0)[4] = span->array->attribs[VARYING_SLOT_COL0];
323 const GLuint n = span->end;
324 GLuint i;
325
326 assert(!(span->arrayAttribs & VARYING_BIT_COL0));
327
328 if (span->arrayMask & SPAN_RGBA) {
329 /* convert array of int colors */
330 for (i = 0; i < n; i++) {
331 col0[i][0] = UBYTE_TO_FLOAT(span->array->rgba8[i][0]);
332 col0[i][1] = UBYTE_TO_FLOAT(span->array->rgba8[i][1]);
333 col0[i][2] = UBYTE_TO_FLOAT(span->array->rgba8[i][2]);
334 col0[i][3] = UBYTE_TO_FLOAT(span->array->rgba8[i][3]);
335 }
336 }
337 else {
338 /* interpolate red/green/blue/alpha to get float colors */
339 ASSERT(span->interpMask & SPAN_RGBA);
340 if (span->interpMask & SPAN_FLAT) {
341 GLfloat r = FixedToFloat(span->red);
342 GLfloat g = FixedToFloat(span->green);
343 GLfloat b = FixedToFloat(span->blue);
344 GLfloat a = FixedToFloat(span->alpha);
345 for (i = 0; i < n; i++) {
346 ASSIGN_4V(col0[i], r, g, b, a);
347 }
348 }
349 else {
350 GLfloat r = FixedToFloat(span->red);
351 GLfloat g = FixedToFloat(span->green);
352 GLfloat b = FixedToFloat(span->blue);
353 GLfloat a = FixedToFloat(span->alpha);
354 GLfloat dr = FixedToFloat(span->redStep);
355 GLfloat dg = FixedToFloat(span->greenStep);
356 GLfloat db = FixedToFloat(span->blueStep);
357 GLfloat da = FixedToFloat(span->alphaStep);
358 for (i = 0; i < n; i++) {
359 col0[i][0] = r;
360 col0[i][1] = g;
361 col0[i][2] = b;
362 col0[i][3] = a;
363 r += dr;
364 g += dg;
365 b += db;
366 a += da;
367 }
368 }
369 }
370
371 span->arrayAttribs |= VARYING_BIT_COL0;
372 span->array->ChanType = GL_FLOAT;
373 }
374
375
376
377 /**
378 * Fill in the span.zArray array from the span->z, zStep values.
379 */
380 void
381 _swrast_span_interpolate_z( const struct gl_context *ctx, SWspan *span )
382 {
383 const GLuint n = span->end;
384 GLuint i;
385
386 ASSERT(!(span->arrayMask & SPAN_Z));
387
388 if (ctx->DrawBuffer->Visual.depthBits <= 16) {
389 GLfixed zval = span->z;
390 GLuint *z = span->array->z;
391 for (i = 0; i < n; i++) {
392 z[i] = FixedToInt(zval);
393 zval += span->zStep;
394 }
395 }
396 else {
397 /* Deep Z buffer, no fixed->int shift */
398 GLuint zval = span->z;
399 GLuint *z = span->array->z;
400 for (i = 0; i < n; i++) {
401 z[i] = zval;
402 zval += span->zStep;
403 }
404 }
405 span->interpMask &= ~SPAN_Z;
406 span->arrayMask |= SPAN_Z;
407 }
408
409
410 /**
411 * Compute mipmap LOD from partial derivatives.
412 * This the ideal solution, as given in the OpenGL spec.
413 */
414 GLfloat
415 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
416 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
417 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
418 {
419 GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);
420 GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);
421 GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);
422 GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);
423 GLfloat x = sqrtf(dudx * dudx + dvdx * dvdx);
424 GLfloat y = sqrtf(dudy * dudy + dvdy * dvdy);
425 GLfloat rho = MAX2(x, y);
426 GLfloat lambda = LOG2(rho);
427 return lambda;
428 }
429
430
431 /**
432 * Compute mipmap LOD from partial derivatives.
433 * This is a faster approximation than above function.
434 */
435 #if 0
436 GLfloat
437 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
438 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
439 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
440 {
441 GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;
442 GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;
443 GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;
444 GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;
445 GLfloat maxU, maxV, rho, lambda;
446 dsdx2 = FABSF(dsdx2);
447 dsdy2 = FABSF(dsdy2);
448 dtdx2 = FABSF(dtdx2);
449 dtdy2 = FABSF(dtdy2);
450 maxU = MAX2(dsdx2, dsdy2) * texW;
451 maxV = MAX2(dtdx2, dtdy2) * texH;
452 rho = MAX2(maxU, maxV);
453 lambda = LOG2(rho);
454 return lambda;
455 }
456 #endif
457
458
459 /**
460 * Fill in the span.array->attrib[VARYING_SLOT_TEXn] arrays from the
461 * using the attrStart/Step values.
462 *
463 * This function only used during fixed-function fragment processing.
464 *
465 * Note: in the places where we divide by Q (or mult by invQ) we're
466 * really doing two things: perspective correction and texcoord
467 * projection. Remember, for texcoord (s,t,r,q) we need to index
468 * texels with (s/q, t/q, r/q).
469 */
470 static void
471 interpolate_texcoords(struct gl_context *ctx, SWspan *span)
472 {
473 const GLuint maxUnit
474 = (ctx->Texture._EnabledCoordUnits > 1) ? ctx->Const.MaxTextureUnits : 1;
475 GLuint u;
476
477 /* XXX CoordUnits vs. ImageUnits */
478 for (u = 0; u < maxUnit; u++) {
479 if (ctx->Texture._EnabledCoordUnits & (1 << u)) {
480 const GLuint attr = VARYING_SLOT_TEX0 + u;
481 const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
482 GLfloat texW, texH;
483 GLboolean needLambda;
484 GLfloat (*texcoord)[4] = span->array->attribs[attr];
485 GLfloat *lambda = span->array->lambda[u];
486 const GLfloat dsdx = span->attrStepX[attr][0];
487 const GLfloat dsdy = span->attrStepY[attr][0];
488 const GLfloat dtdx = span->attrStepX[attr][1];
489 const GLfloat dtdy = span->attrStepY[attr][1];
490 const GLfloat drdx = span->attrStepX[attr][2];
491 const GLfloat dqdx = span->attrStepX[attr][3];
492 const GLfloat dqdy = span->attrStepY[attr][3];
493 GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx;
494 GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx;
495 GLfloat r = span->attrStart[attr][2] + span->leftClip * drdx;
496 GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx;
497
498 if (obj) {
499 const struct gl_texture_image *img = _mesa_base_tex_image(obj);
500 const struct swrast_texture_image *swImg =
501 swrast_texture_image_const(img);
502 const struct gl_sampler_object *samp = _mesa_get_samplerobj(ctx, u);
503
504 needLambda = (samp->MinFilter != samp->MagFilter)
505 || _swrast_use_fragment_program(ctx);
506 /* LOD is calculated directly in the ansiotropic filter, we can
507 * skip the normal lambda function as the result is ignored.
508 */
509 if (samp->MaxAnisotropy > 1.0 &&
510 samp->MinFilter == GL_LINEAR_MIPMAP_LINEAR) {
511 needLambda = GL_FALSE;
512 }
513 texW = swImg->WidthScale;
514 texH = swImg->HeightScale;
515 }
516 else {
517 /* using a fragment program */
518 texW = 1.0;
519 texH = 1.0;
520 needLambda = GL_FALSE;
521 }
522
523 if (needLambda) {
524 GLuint i;
525 if (_swrast_use_fragment_program(ctx)
526 || ctx->ATIFragmentShader._Enabled) {
527 /* do perspective correction but don't divide s, t, r by q */
528 const GLfloat dwdx = span->attrStepX[VARYING_SLOT_POS][3];
529 GLfloat w = span->attrStart[VARYING_SLOT_POS][3] + span->leftClip * dwdx;
530 for (i = 0; i < span->end; i++) {
531 const GLfloat invW = 1.0F / w;
532 texcoord[i][0] = s * invW;
533 texcoord[i][1] = t * invW;
534 texcoord[i][2] = r * invW;
535 texcoord[i][3] = q * invW;
536 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
537 dqdx, dqdy, texW, texH,
538 s, t, q, invW);
539 s += dsdx;
540 t += dtdx;
541 r += drdx;
542 q += dqdx;
543 w += dwdx;
544 }
545 }
546 else {
547 for (i = 0; i < span->end; i++) {
548 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
549 texcoord[i][0] = s * invQ;
550 texcoord[i][1] = t * invQ;
551 texcoord[i][2] = r * invQ;
552 texcoord[i][3] = q;
553 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
554 dqdx, dqdy, texW, texH,
555 s, t, q, invQ);
556 s += dsdx;
557 t += dtdx;
558 r += drdx;
559 q += dqdx;
560 }
561 }
562 span->arrayMask |= SPAN_LAMBDA;
563 }
564 else {
565 GLuint i;
566 if (_swrast_use_fragment_program(ctx) ||
567 ctx->ATIFragmentShader._Enabled) {
568 /* do perspective correction but don't divide s, t, r by q */
569 const GLfloat dwdx = span->attrStepX[VARYING_SLOT_POS][3];
570 GLfloat w = span->attrStart[VARYING_SLOT_POS][3] + span->leftClip * dwdx;
571 for (i = 0; i < span->end; i++) {
572 const GLfloat invW = 1.0F / w;
573 texcoord[i][0] = s * invW;
574 texcoord[i][1] = t * invW;
575 texcoord[i][2] = r * invW;
576 texcoord[i][3] = q * invW;
577 lambda[i] = 0.0;
578 s += dsdx;
579 t += dtdx;
580 r += drdx;
581 q += dqdx;
582 w += dwdx;
583 }
584 }
585 else if (dqdx == 0.0F) {
586 /* Ortho projection or polygon's parallel to window X axis */
587 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
588 for (i = 0; i < span->end; i++) {
589 texcoord[i][0] = s * invQ;
590 texcoord[i][1] = t * invQ;
591 texcoord[i][2] = r * invQ;
592 texcoord[i][3] = q;
593 lambda[i] = 0.0;
594 s += dsdx;
595 t += dtdx;
596 r += drdx;
597 }
598 }
599 else {
600 for (i = 0; i < span->end; i++) {
601 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
602 texcoord[i][0] = s * invQ;
603 texcoord[i][1] = t * invQ;
604 texcoord[i][2] = r * invQ;
605 texcoord[i][3] = q;
606 lambda[i] = 0.0;
607 s += dsdx;
608 t += dtdx;
609 r += drdx;
610 q += dqdx;
611 }
612 }
613 } /* lambda */
614 } /* if */
615 } /* for */
616 }
617
618
619 /**
620 * Fill in the arrays->attribs[VARYING_SLOT_POS] array.
621 */
622 static inline void
623 interpolate_wpos(struct gl_context *ctx, SWspan *span)
624 {
625 GLfloat (*wpos)[4] = span->array->attribs[VARYING_SLOT_POS];
626 GLuint i;
627 const GLfloat zScale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
628 GLfloat w, dw;
629
630 if (span->arrayMask & SPAN_XY) {
631 for (i = 0; i < span->end; i++) {
632 wpos[i][0] = (GLfloat) span->array->x[i];
633 wpos[i][1] = (GLfloat) span->array->y[i];
634 }
635 }
636 else {
637 for (i = 0; i < span->end; i++) {
638 wpos[i][0] = (GLfloat) span->x + i;
639 wpos[i][1] = (GLfloat) span->y;
640 }
641 }
642
643 dw = span->attrStepX[VARYING_SLOT_POS][3];
644 w = span->attrStart[VARYING_SLOT_POS][3] + span->leftClip * dw;
645 for (i = 0; i < span->end; i++) {
646 wpos[i][2] = (GLfloat) span->array->z[i] * zScale;
647 wpos[i][3] = w;
648 w += dw;
649 }
650 }
651
652
653 /**
654 * Apply the current polygon stipple pattern to a span of pixels.
655 */
656 static inline void
657 stipple_polygon_span(struct gl_context *ctx, SWspan *span)
658 {
659 GLubyte *mask = span->array->mask;
660
661 ASSERT(ctx->Polygon.StippleFlag);
662
663 if (span->arrayMask & SPAN_XY) {
664 /* arrays of x/y pixel coords */
665 GLuint i;
666 for (i = 0; i < span->end; i++) {
667 const GLint col = span->array->x[i] % 32;
668 const GLint row = span->array->y[i] % 32;
669 const GLuint stipple = ctx->PolygonStipple[row];
670 if (((1 << col) & stipple) == 0) {
671 mask[i] = 0;
672 }
673 }
674 }
675 else {
676 /* horizontal span of pixels */
677 const GLuint highBit = 1 << 31;
678 const GLuint stipple = ctx->PolygonStipple[span->y % 32];
679 GLuint i, m = highBit >> (GLuint) (span->x % 32);
680 for (i = 0; i < span->end; i++) {
681 if ((m & stipple) == 0) {
682 mask[i] = 0;
683 }
684 m = m >> 1;
685 if (m == 0) {
686 m = highBit;
687 }
688 }
689 }
690 span->writeAll = GL_FALSE;
691 }
692
693
694 /**
695 * Clip a pixel span to the current buffer/window boundaries:
696 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
697 * window clipping and scissoring.
698 * Return: GL_TRUE some pixels still visible
699 * GL_FALSE nothing visible
700 */
701 static inline GLuint
702 clip_span( struct gl_context *ctx, SWspan *span )
703 {
704 const GLint xmin = ctx->DrawBuffer->_Xmin;
705 const GLint xmax = ctx->DrawBuffer->_Xmax;
706 const GLint ymin = ctx->DrawBuffer->_Ymin;
707 const GLint ymax = ctx->DrawBuffer->_Ymax;
708
709 span->leftClip = 0;
710
711 if (span->arrayMask & SPAN_XY) {
712 /* arrays of x/y pixel coords */
713 const GLint *x = span->array->x;
714 const GLint *y = span->array->y;
715 const GLint n = span->end;
716 GLubyte *mask = span->array->mask;
717 GLint i;
718 GLuint passed = 0;
719 if (span->arrayMask & SPAN_MASK) {
720 /* note: using & intead of && to reduce branches */
721 for (i = 0; i < n; i++) {
722 mask[i] &= (x[i] >= xmin) & (x[i] < xmax)
723 & (y[i] >= ymin) & (y[i] < ymax);
724 passed += mask[i];
725 }
726 }
727 else {
728 /* note: using & intead of && to reduce branches */
729 for (i = 0; i < n; i++) {
730 mask[i] = (x[i] >= xmin) & (x[i] < xmax)
731 & (y[i] >= ymin) & (y[i] < ymax);
732 passed += mask[i];
733 }
734 }
735 return passed > 0;
736 }
737 else {
738 /* horizontal span of pixels */
739 const GLint x = span->x;
740 const GLint y = span->y;
741 GLint n = span->end;
742
743 /* Trivial rejection tests */
744 if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {
745 span->end = 0;
746 return GL_FALSE; /* all pixels clipped */
747 }
748
749 /* Clip to right */
750 if (x + n > xmax) {
751 ASSERT(x < xmax);
752 n = span->end = xmax - x;
753 }
754
755 /* Clip to the left */
756 if (x < xmin) {
757 const GLint leftClip = xmin - x;
758 GLuint i;
759
760 ASSERT(leftClip > 0);
761 ASSERT(x + n > xmin);
762
763 /* Clip 'leftClip' pixels from the left side.
764 * The span->leftClip field will be applied when we interpolate
765 * fragment attributes.
766 * For arrays of values, shift them left.
767 */
768 for (i = 0; i < VARYING_SLOT_MAX; i++) {
769 if (span->interpMask & (1 << i)) {
770 GLuint j;
771 for (j = 0; j < 4; j++) {
772 span->attrStart[i][j] += leftClip * span->attrStepX[i][j];
773 }
774 }
775 }
776
777 span->red += leftClip * span->redStep;
778 span->green += leftClip * span->greenStep;
779 span->blue += leftClip * span->blueStep;
780 span->alpha += leftClip * span->alphaStep;
781 span->index += leftClip * span->indexStep;
782 span->z += leftClip * span->zStep;
783 span->intTex[0] += leftClip * span->intTexStep[0];
784 span->intTex[1] += leftClip * span->intTexStep[1];
785
786 #define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
787 memmove(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
788
789 for (i = 0; i < VARYING_SLOT_MAX; i++) {
790 if (span->arrayAttribs & (1 << i)) {
791 /* shift array elements left by 'leftClip' */
792 SHIFT_ARRAY(span->array->attribs[i], leftClip, n - leftClip);
793 }
794 }
795
796 SHIFT_ARRAY(span->array->mask, leftClip, n - leftClip);
797 SHIFT_ARRAY(span->array->rgba8, leftClip, n - leftClip);
798 SHIFT_ARRAY(span->array->rgba16, leftClip, n - leftClip);
799 SHIFT_ARRAY(span->array->x, leftClip, n - leftClip);
800 SHIFT_ARRAY(span->array->y, leftClip, n - leftClip);
801 SHIFT_ARRAY(span->array->z, leftClip, n - leftClip);
802 SHIFT_ARRAY(span->array->index, leftClip, n - leftClip);
803 for (i = 0; i < MAX_TEXTURE_COORD_UNITS; i++) {
804 SHIFT_ARRAY(span->array->lambda[i], leftClip, n - leftClip);
805 }
806 SHIFT_ARRAY(span->array->coverage, leftClip, n - leftClip);
807
808 #undef SHIFT_ARRAY
809
810 span->leftClip = leftClip;
811 span->x = xmin;
812 span->end -= leftClip;
813 span->writeAll = GL_FALSE;
814 }
815
816 ASSERT(span->x >= xmin);
817 ASSERT(span->x + span->end <= xmax);
818 ASSERT(span->y >= ymin);
819 ASSERT(span->y < ymax);
820
821 return GL_TRUE; /* some pixels visible */
822 }
823 }
824
825
826 /**
827 * Add specular colors to primary colors.
828 * Only called during fixed-function operation.
829 * Result is float color array (VARYING_SLOT_COL0).
830 */
831 static inline void
832 add_specular(struct gl_context *ctx, SWspan *span)
833 {
834 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
835 const GLubyte *mask = span->array->mask;
836 GLfloat (*col0)[4] = span->array->attribs[VARYING_SLOT_COL0];
837 GLfloat (*col1)[4] = span->array->attribs[VARYING_SLOT_COL1];
838 GLuint i;
839
840 ASSERT(!_swrast_use_fragment_program(ctx));
841 ASSERT(span->arrayMask & SPAN_RGBA);
842 ASSERT(swrast->_ActiveAttribMask & VARYING_BIT_COL1);
843 (void) swrast; /* silence warning */
844
845 if (span->array->ChanType == GL_FLOAT) {
846 if ((span->arrayAttribs & VARYING_BIT_COL0) == 0) {
847 interpolate_active_attribs(ctx, span, VARYING_BIT_COL0);
848 }
849 }
850 else {
851 /* need float colors */
852 if ((span->arrayAttribs & VARYING_BIT_COL0) == 0) {
853 interpolate_float_colors(span);
854 }
855 }
856
857 if ((span->arrayAttribs & VARYING_BIT_COL1) == 0) {
858 /* XXX could avoid this and interpolate COL1 in the loop below */
859 interpolate_active_attribs(ctx, span, VARYING_BIT_COL1);
860 }
861
862 ASSERT(span->arrayAttribs & VARYING_BIT_COL0);
863 ASSERT(span->arrayAttribs & VARYING_BIT_COL1);
864
865 for (i = 0; i < span->end; i++) {
866 if (mask[i]) {
867 col0[i][0] += col1[i][0];
868 col0[i][1] += col1[i][1];
869 col0[i][2] += col1[i][2];
870 }
871 }
872
873 span->array->ChanType = GL_FLOAT;
874 }
875
876
877 /**
878 * Apply antialiasing coverage value to alpha values.
879 */
880 static inline void
881 apply_aa_coverage(SWspan *span)
882 {
883 const GLfloat *coverage = span->array->coverage;
884 GLuint i;
885 if (span->array->ChanType == GL_UNSIGNED_BYTE) {
886 GLubyte (*rgba)[4] = span->array->rgba8;
887 for (i = 0; i < span->end; i++) {
888 const GLfloat a = rgba[i][ACOMP] * coverage[i];
889 rgba[i][ACOMP] = (GLubyte) CLAMP(a, 0.0, 255.0);
890 ASSERT(coverage[i] >= 0.0);
891 ASSERT(coverage[i] <= 1.0);
892 }
893 }
894 else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
895 GLushort (*rgba)[4] = span->array->rgba16;
896 for (i = 0; i < span->end; i++) {
897 const GLfloat a = rgba[i][ACOMP] * coverage[i];
898 rgba[i][ACOMP] = (GLushort) CLAMP(a, 0.0, 65535.0);
899 }
900 }
901 else {
902 GLfloat (*rgba)[4] = span->array->attribs[VARYING_SLOT_COL0];
903 for (i = 0; i < span->end; i++) {
904 rgba[i][ACOMP] = rgba[i][ACOMP] * coverage[i];
905 /* clamp later */
906 }
907 }
908 }
909
910
911 /**
912 * Clamp span's float colors to [0,1]
913 */
914 static inline void
915 clamp_colors(SWspan *span)
916 {
917 GLfloat (*rgba)[4] = span->array->attribs[VARYING_SLOT_COL0];
918 GLuint i;
919 ASSERT(span->array->ChanType == GL_FLOAT);
920 for (i = 0; i < span->end; i++) {
921 rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
922 rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
923 rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
924 rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
925 }
926 }
927
928
929 /**
930 * Convert the span's color arrays to the given type.
931 * The only way 'output' can be greater than zero is when we have a fragment
932 * program that writes to gl_FragData[1] or higher.
933 * \param output which fragment program color output is being processed
934 */
935 static inline void
936 convert_color_type(SWspan *span, GLenum srcType, GLenum newType, GLuint output)
937 {
938 GLvoid *src, *dst;
939
940 if (output > 0 || srcType == GL_FLOAT) {
941 src = span->array->attribs[VARYING_SLOT_COL0 + output];
942 span->array->ChanType = GL_FLOAT;
943 }
944 else if (srcType == GL_UNSIGNED_BYTE) {
945 src = span->array->rgba8;
946 }
947 else {
948 ASSERT(srcType == GL_UNSIGNED_SHORT);
949 src = span->array->rgba16;
950 }
951
952 if (newType == GL_UNSIGNED_BYTE) {
953 dst = span->array->rgba8;
954 }
955 else if (newType == GL_UNSIGNED_SHORT) {
956 dst = span->array->rgba16;
957 }
958 else {
959 dst = span->array->attribs[VARYING_SLOT_COL0];
960 }
961
962 _mesa_convert_colors(span->array->ChanType, src,
963 newType, dst,
964 span->end, span->array->mask);
965
966 span->array->ChanType = newType;
967 span->array->rgba = dst;
968 }
969
970
971
972 /**
973 * Apply fragment shader, fragment program or normal texturing to span.
974 */
975 static inline void
976 shade_texture_span(struct gl_context *ctx, SWspan *span)
977 {
978 if (_swrast_use_fragment_program(ctx) ||
979 ctx->ATIFragmentShader._Enabled) {
980 /* programmable shading */
981 if (span->primitive == GL_BITMAP && span->array->ChanType != GL_FLOAT) {
982 convert_color_type(span, span->array->ChanType, GL_FLOAT, 0);
983 }
984 else {
985 span->array->rgba = (void *) span->array->attribs[VARYING_SLOT_COL0];
986 }
987
988 if (span->primitive != GL_POINT ||
989 (span->interpMask & SPAN_RGBA) ||
990 ctx->Point.PointSprite) {
991 /* for single-pixel points, we populated the arrays already */
992 interpolate_active_attribs(ctx, span, ~0);
993 }
994 span->array->ChanType = GL_FLOAT;
995
996 if (!(span->arrayMask & SPAN_Z))
997 _swrast_span_interpolate_z (ctx, span);
998
999 #if 0
1000 if (inputsRead & VARYING_BIT_POS)
1001 #else
1002 /* XXX always interpolate wpos so that DDX/DDY work */
1003 #endif
1004 interpolate_wpos(ctx, span);
1005
1006 /* Run fragment program/shader now */
1007 if (_swrast_use_fragment_program(ctx)) {
1008 _swrast_exec_fragment_program(ctx, span);
1009 }
1010 else {
1011 ASSERT(ctx->ATIFragmentShader._Enabled);
1012 _swrast_exec_fragment_shader(ctx, span);
1013 }
1014 }
1015 else if (ctx->Texture._EnabledCoordUnits) {
1016 /* conventional texturing */
1017
1018 #if CHAN_BITS == 32
1019 if ((span->arrayAttribs & VARYING_BIT_COL0) == 0) {
1020 interpolate_int_colors(ctx, span);
1021 }
1022 #else
1023 if (!(span->arrayMask & SPAN_RGBA))
1024 interpolate_int_colors(ctx, span);
1025 #endif
1026 if ((span->arrayAttribs & VARYING_BITS_TEX_ANY) == 0x0)
1027 interpolate_texcoords(ctx, span);
1028
1029 _swrast_texture_span(ctx, span);
1030 }
1031 }
1032
1033
1034 /** Put colors at x/y locations into a renderbuffer */
1035 static void
1036 put_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1037 GLenum datatype,
1038 GLuint count, const GLint x[], const GLint y[],
1039 const void *values, const GLubyte *mask)
1040 {
1041 gl_pack_ubyte_rgba_func pack_ubyte = NULL;
1042 gl_pack_float_rgba_func pack_float = NULL;
1043 GLuint i;
1044
1045 if (datatype == GL_UNSIGNED_BYTE)
1046 pack_ubyte = _mesa_get_pack_ubyte_rgba_function(rb->Format);
1047 else
1048 pack_float = _mesa_get_pack_float_rgba_function(rb->Format);
1049
1050 for (i = 0; i < count; i++) {
1051 if (mask[i]) {
1052 GLubyte *dst = _swrast_pixel_address(rb, x[i], y[i]);
1053
1054 if (datatype == GL_UNSIGNED_BYTE) {
1055 pack_ubyte((const GLubyte *) values + 4 * i, dst);
1056 }
1057 else {
1058 assert(datatype == GL_FLOAT);
1059 pack_float((const GLfloat *) values + 4 * i, dst);
1060 }
1061 }
1062 }
1063 }
1064
1065
1066 /** Put row of colors into renderbuffer */
1067 void
1068 _swrast_put_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1069 GLenum datatype,
1070 GLuint count, GLint x, GLint y,
1071 const void *values, const GLubyte *mask)
1072 {
1073 GLubyte *dst = _swrast_pixel_address(rb, x, y);
1074
1075 if (!mask) {
1076 if (datatype == GL_UNSIGNED_BYTE) {
1077 _mesa_pack_ubyte_rgba_row(rb->Format, count,
1078 (const GLubyte (*)[4]) values, dst);
1079 }
1080 else {
1081 assert(datatype == GL_FLOAT);
1082 _mesa_pack_float_rgba_row(rb->Format, count,
1083 (const GLfloat (*)[4]) values, dst);
1084 }
1085 }
1086 else {
1087 const GLuint bpp = _mesa_get_format_bytes(rb->Format);
1088 GLuint i, runLen, runStart;
1089 /* We can't pass a 'mask' array to the _mesa_pack_rgba_row() functions
1090 * so look for runs where mask=1...
1091 */
1092 runLen = runStart = 0;
1093 for (i = 0; i < count; i++) {
1094 if (mask[i]) {
1095 if (runLen == 0)
1096 runStart = i;
1097 runLen++;
1098 }
1099
1100 if (!mask[i] || i == count - 1) {
1101 /* might be the end of a run of pixels */
1102 if (runLen > 0) {
1103 if (datatype == GL_UNSIGNED_BYTE) {
1104 _mesa_pack_ubyte_rgba_row(rb->Format, runLen,
1105 (const GLubyte (*)[4]) values + runStart,
1106 dst + runStart * bpp);
1107 }
1108 else {
1109 assert(datatype == GL_FLOAT);
1110 _mesa_pack_float_rgba_row(rb->Format, runLen,
1111 (const GLfloat (*)[4]) values + runStart,
1112 dst + runStart * bpp);
1113 }
1114 runLen = 0;
1115 }
1116 }
1117 }
1118 }
1119 }
1120
1121
1122
1123 /**
1124 * Apply all the per-fragment operations to a span.
1125 * This now includes texturing (_swrast_write_texture_span() is history).
1126 * This function may modify any of the array values in the span.
1127 * span->interpMask and span->arrayMask may be changed but will be restored
1128 * to their original values before returning.
1129 */
1130 void
1131 _swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)
1132 {
1133 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
1134 const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;
1135 const GLbitfield origInterpMask = span->interpMask;
1136 const GLbitfield origArrayMask = span->arrayMask;
1137 const GLbitfield64 origArrayAttribs = span->arrayAttribs;
1138 const GLenum origChanType = span->array->ChanType;
1139 void * const origRgba = span->array->rgba;
1140 const GLboolean shader = (_swrast_use_fragment_program(ctx)
1141 || ctx->ATIFragmentShader._Enabled);
1142 const GLboolean shaderOrTexture = shader || ctx->Texture._EnabledCoordUnits;
1143 struct gl_framebuffer *fb = ctx->DrawBuffer;
1144
1145 /*
1146 printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__,
1147 span->interpMask, span->arrayMask);
1148 */
1149
1150 ASSERT(span->primitive == GL_POINT ||
1151 span->primitive == GL_LINE ||
1152 span->primitive == GL_POLYGON ||
1153 span->primitive == GL_BITMAP);
1154
1155 /* Fragment write masks */
1156 if (span->arrayMask & SPAN_MASK) {
1157 /* mask was initialized by caller, probably glBitmap */
1158 span->writeAll = GL_FALSE;
1159 }
1160 else {
1161 memset(span->array->mask, 1, span->end);
1162 span->writeAll = GL_TRUE;
1163 }
1164
1165 /* Clip to window/scissor box */
1166 if (!clip_span(ctx, span)) {
1167 return;
1168 }
1169
1170 ASSERT(span->end <= SWRAST_MAX_WIDTH);
1171
1172 /* Depth bounds test */
1173 if (ctx->Depth.BoundsTest && fb->Visual.depthBits > 0) {
1174 if (!_swrast_depth_bounds_test(ctx, span)) {
1175 return;
1176 }
1177 }
1178
1179 #ifdef DEBUG
1180 /* Make sure all fragments are within window bounds */
1181 if (span->arrayMask & SPAN_XY) {
1182 /* array of pixel locations */
1183 GLuint i;
1184 for (i = 0; i < span->end; i++) {
1185 if (span->array->mask[i]) {
1186 assert(span->array->x[i] >= fb->_Xmin);
1187 assert(span->array->x[i] < fb->_Xmax);
1188 assert(span->array->y[i] >= fb->_Ymin);
1189 assert(span->array->y[i] < fb->_Ymax);
1190 }
1191 }
1192 }
1193 #endif
1194
1195 /* Polygon Stippling */
1196 if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
1197 stipple_polygon_span(ctx, span);
1198 }
1199
1200 /* This is the normal place to compute the fragment color/Z
1201 * from texturing or shading.
1202 */
1203 if (shaderOrTexture && !swrast->_DeferredTexture) {
1204 shade_texture_span(ctx, span);
1205 }
1206
1207 /* Do the alpha test */
1208 if (ctx->Color.AlphaEnabled) {
1209 if (!_swrast_alpha_test(ctx, span)) {
1210 /* all fragments failed test */
1211 goto end;
1212 }
1213 }
1214
1215 /* Stencil and Z testing */
1216 if (ctx->Stencil._Enabled || ctx->Depth.Test) {
1217 if (!(span->arrayMask & SPAN_Z))
1218 _swrast_span_interpolate_z(ctx, span);
1219
1220 if (ctx->Transform.DepthClamp)
1221 _swrast_depth_clamp_span(ctx, span);
1222
1223 if (ctx->Stencil._Enabled) {
1224 /* Combined Z/stencil tests */
1225 if (!_swrast_stencil_and_ztest_span(ctx, span)) {
1226 /* all fragments failed test */
1227 goto end;
1228 }
1229 }
1230 else if (fb->Visual.depthBits > 0) {
1231 /* Just regular depth testing */
1232 ASSERT(ctx->Depth.Test);
1233 ASSERT(span->arrayMask & SPAN_Z);
1234 if (!_swrast_depth_test_span(ctx, span)) {
1235 /* all fragments failed test */
1236 goto end;
1237 }
1238 }
1239 }
1240
1241 if (ctx->Query.CurrentOcclusionObject) {
1242 /* update count of 'passed' fragments */
1243 struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
1244 GLuint i;
1245 for (i = 0; i < span->end; i++)
1246 q->Result += span->array->mask[i];
1247 }
1248
1249 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1250 * the occlusion test.
1251 */
1252 if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {
1253 /* no colors to write */
1254 goto end;
1255 }
1256
1257 /* If we were able to defer fragment color computation to now, there's
1258 * a good chance that many fragments will have already been killed by
1259 * Z/stencil testing.
1260 */
1261 if (shaderOrTexture && swrast->_DeferredTexture) {
1262 shade_texture_span(ctx, span);
1263 }
1264
1265 #if CHAN_BITS == 32
1266 if ((span->arrayAttribs & VARYING_BIT_COL0) == 0) {
1267 interpolate_active_attribs(ctx, span, VARYING_BIT_COL0);
1268 }
1269 #else
1270 if ((span->arrayMask & SPAN_RGBA) == 0) {
1271 interpolate_int_colors(ctx, span);
1272 }
1273 #endif
1274
1275 ASSERT(span->arrayMask & SPAN_RGBA);
1276
1277 if (span->primitive == GL_BITMAP || !swrast->SpecularVertexAdd) {
1278 /* Add primary and specular (diffuse + specular) colors */
1279 if (!shader) {
1280 if (ctx->Fog.ColorSumEnabled ||
1281 (ctx->Light.Enabled &&
1282 ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {
1283 add_specular(ctx, span);
1284 }
1285 }
1286 }
1287
1288 /* Fog */
1289 if (swrast->_FogEnabled) {
1290 _swrast_fog_rgba_span(ctx, span);
1291 }
1292
1293 /* Antialias coverage application */
1294 if (span->arrayMask & SPAN_COVERAGE) {
1295 apply_aa_coverage(span);
1296 }
1297
1298 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1299 if (ctx->Color.ClampFragmentColor == GL_TRUE &&
1300 span->array->ChanType == GL_FLOAT) {
1301 clamp_colors(span);
1302 }
1303
1304 /*
1305 * Write to renderbuffers.
1306 * Depending on glDrawBuffer() state and the which color outputs are
1307 * written by the fragment shader, we may either replicate one color to
1308 * all renderbuffers or write a different color to each renderbuffer.
1309 * multiFragOutputs=TRUE for the later case.
1310 */
1311 {
1312 const GLuint numBuffers = fb->_NumColorDrawBuffers;
1313 const struct gl_fragment_program *fp = ctx->FragmentProgram._Current;
1314 const GLboolean multiFragOutputs =
1315 _swrast_use_fragment_program(ctx)
1316 && fp->Base.OutputsWritten >= (1 << FRAG_RESULT_DATA0);
1317 /* Save srcColorType because convert_color_type() can change it */
1318 const GLenum srcColorType = span->array->ChanType;
1319 GLuint buf;
1320
1321 for (buf = 0; buf < numBuffers; buf++) {
1322 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];
1323
1324 /* color[fragOutput] will be written to buffer[buf] */
1325
1326 if (rb) {
1327 /* re-use one of the attribute array buffers for rgbaSave */
1328 GLchan (*rgbaSave)[4] = (GLchan (*)[4]) span->array->attribs[0];
1329 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
1330 const GLenum dstColorType = srb->ColorType;
1331
1332 assert(dstColorType == GL_UNSIGNED_BYTE ||
1333 dstColorType == GL_FLOAT);
1334
1335 /* set span->array->rgba to colors for renderbuffer's datatype */
1336 if (srcColorType != dstColorType) {
1337 convert_color_type(span, srcColorType, dstColorType,
1338 multiFragOutputs ? buf : 0);
1339 }
1340 else {
1341 if (srcColorType == GL_UNSIGNED_BYTE) {
1342 span->array->rgba = span->array->rgba8;
1343 }
1344 else {
1345 span->array->rgba = (void *)
1346 span->array->attribs[VARYING_SLOT_COL0];
1347 }
1348 }
1349
1350 if (!multiFragOutputs && numBuffers > 1) {
1351 /* save colors for second, third renderbuffer writes */
1352 memcpy(rgbaSave, span->array->rgba,
1353 4 * span->end * sizeof(GLchan));
1354 }
1355
1356 ASSERT(rb->_BaseFormat == GL_RGBA ||
1357 rb->_BaseFormat == GL_RGB ||
1358 rb->_BaseFormat == GL_RED ||
1359 rb->_BaseFormat == GL_RG ||
1360 rb->_BaseFormat == GL_ALPHA);
1361
1362 if (ctx->Color.ColorLogicOpEnabled) {
1363 _swrast_logicop_rgba_span(ctx, rb, span);
1364 }
1365 else if ((ctx->Color.BlendEnabled >> buf) & 1) {
1366 _swrast_blend_span(ctx, rb, span);
1367 }
1368
1369 if (colorMask[buf] != 0xffffffff) {
1370 _swrast_mask_rgba_span(ctx, rb, span, buf);
1371 }
1372
1373 if (span->arrayMask & SPAN_XY) {
1374 /* array of pixel coords */
1375 put_values(ctx, rb,
1376 span->array->ChanType, span->end,
1377 span->array->x, span->array->y,
1378 span->array->rgba, span->array->mask);
1379 }
1380 else {
1381 /* horizontal run of pixels */
1382 _swrast_put_row(ctx, rb,
1383 span->array->ChanType,
1384 span->end, span->x, span->y,
1385 span->array->rgba,
1386 span->writeAll ? NULL: span->array->mask);
1387 }
1388
1389 if (!multiFragOutputs && numBuffers > 1) {
1390 /* restore original span values */
1391 memcpy(span->array->rgba, rgbaSave,
1392 4 * span->end * sizeof(GLchan));
1393 }
1394
1395 } /* if rb */
1396 } /* for buf */
1397 }
1398
1399 end:
1400 /* restore these values before returning */
1401 span->interpMask = origInterpMask;
1402 span->arrayMask = origArrayMask;
1403 span->arrayAttribs = origArrayAttribs;
1404 span->array->ChanType = origChanType;
1405 span->array->rgba = origRgba;
1406 }
1407
1408
1409 /**
1410 * Read float RGBA pixels from a renderbuffer. Clipping will be done to
1411 * prevent reading ouside the buffer's boundaries.
1412 * \param rgba the returned colors
1413 */
1414 void
1415 _swrast_read_rgba_span( struct gl_context *ctx, struct gl_renderbuffer *rb,
1416 GLuint n, GLint x, GLint y,
1417 GLvoid *rgba)
1418 {
1419 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
1420 GLenum dstType = GL_FLOAT;
1421 const GLint bufWidth = (GLint) rb->Width;
1422 const GLint bufHeight = (GLint) rb->Height;
1423
1424 if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
1425 /* completely above, below, or right */
1426 /* XXX maybe leave rgba values undefined? */
1427 memset(rgba, 0, 4 * n * sizeof(GLchan));
1428 }
1429 else {
1430 GLint skip, length;
1431 GLubyte *src;
1432
1433 if (x < 0) {
1434 /* left edge clipping */
1435 skip = -x;
1436 length = (GLint) n - skip;
1437 if (length < 0) {
1438 /* completely left of window */
1439 return;
1440 }
1441 if (length > bufWidth) {
1442 length = bufWidth;
1443 }
1444 }
1445 else if ((GLint) (x + n) > bufWidth) {
1446 /* right edge clipping */
1447 skip = 0;
1448 length = bufWidth - x;
1449 if (length < 0) {
1450 /* completely to right of window */
1451 return;
1452 }
1453 }
1454 else {
1455 /* no clipping */
1456 skip = 0;
1457 length = (GLint) n;
1458 }
1459
1460 ASSERT(rb);
1461 ASSERT(rb->_BaseFormat == GL_RGBA ||
1462 rb->_BaseFormat == GL_RGB ||
1463 rb->_BaseFormat == GL_RG ||
1464 rb->_BaseFormat == GL_RED ||
1465 rb->_BaseFormat == GL_LUMINANCE ||
1466 rb->_BaseFormat == GL_INTENSITY ||
1467 rb->_BaseFormat == GL_LUMINANCE_ALPHA ||
1468 rb->_BaseFormat == GL_ALPHA);
1469
1470 assert(srb->Map);
1471
1472 src = _swrast_pixel_address(rb, x + skip, y);
1473
1474 if (dstType == GL_UNSIGNED_BYTE) {
1475 _mesa_unpack_ubyte_rgba_row(rb->Format, length, src,
1476 (GLubyte (*)[4]) rgba + skip);
1477 }
1478 else if (dstType == GL_FLOAT) {
1479 _mesa_unpack_rgba_row(rb->Format, length, src,
1480 (GLfloat (*)[4]) rgba + skip);
1481 }
1482 else {
1483 _mesa_problem(ctx, "unexpected type in _swrast_read_rgba_span()");
1484 }
1485 }
1486 }
1487
1488
1489 /**
1490 * Get colors at x/y positions with clipping.
1491 * \param type type of values to return
1492 */
1493 static void
1494 get_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1495 GLuint count, const GLint x[], const GLint y[],
1496 void *values, GLenum type)
1497 {
1498 GLuint i;
1499
1500 for (i = 0; i < count; i++) {
1501 if (x[i] >= 0 && y[i] >= 0 &&
1502 x[i] < (GLint) rb->Width && y[i] < (GLint) rb->Height) {
1503 /* inside */
1504 const GLubyte *src = _swrast_pixel_address(rb, x[i], y[i]);
1505
1506 if (type == GL_UNSIGNED_BYTE) {
1507 _mesa_unpack_ubyte_rgba_row(rb->Format, 1, src,
1508 (GLubyte (*)[4]) values + i);
1509 }
1510 else if (type == GL_FLOAT) {
1511 _mesa_unpack_rgba_row(rb->Format, 1, src,
1512 (GLfloat (*)[4]) values + i);
1513 }
1514 else {
1515 _mesa_problem(ctx, "unexpected type in get_values()");
1516 }
1517 }
1518 }
1519 }
1520
1521
1522 /**
1523 * Get row of colors with clipping.
1524 * \param type type of values to return
1525 */
1526 static void
1527 get_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1528 GLuint count, GLint x, GLint y,
1529 GLvoid *values, GLenum type)
1530 {
1531 GLint skip = 0;
1532 GLubyte *src;
1533
1534 if (y < 0 || y >= (GLint) rb->Height)
1535 return; /* above or below */
1536
1537 if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
1538 return; /* entirely left or right */
1539
1540 if (x + count > rb->Width) {
1541 /* right clip */
1542 GLint clip = x + count - rb->Width;
1543 count -= clip;
1544 }
1545
1546 if (x < 0) {
1547 /* left clip */
1548 skip = -x;
1549 x = 0;
1550 count -= skip;
1551 }
1552
1553 src = _swrast_pixel_address(rb, x, y);
1554
1555 if (type == GL_UNSIGNED_BYTE) {
1556 _mesa_unpack_ubyte_rgba_row(rb->Format, count, src,
1557 (GLubyte (*)[4]) values + skip);
1558 }
1559 else if (type == GL_FLOAT) {
1560 _mesa_unpack_rgba_row(rb->Format, count, src,
1561 (GLfloat (*)[4]) values + skip);
1562 }
1563 else {
1564 _mesa_problem(ctx, "unexpected type in get_row()");
1565 }
1566 }
1567
1568
1569 /**
1570 * Get RGBA pixels from the given renderbuffer.
1571 * Used by blending, logicop and masking functions.
1572 * \return pointer to the colors we read.
1573 */
1574 void *
1575 _swrast_get_dest_rgba(struct gl_context *ctx, struct gl_renderbuffer *rb,
1576 SWspan *span)
1577 {
1578 void *rbPixels;
1579
1580 /* Point rbPixels to a temporary space */
1581 rbPixels = span->array->attribs[VARYING_SLOT_MAX - 1];
1582
1583 /* Get destination values from renderbuffer */
1584 if (span->arrayMask & SPAN_XY) {
1585 get_values(ctx, rb, span->end, span->array->x, span->array->y,
1586 rbPixels, span->array->ChanType);
1587 }
1588 else {
1589 get_row(ctx, rb, span->end, span->x, span->y,
1590 rbPixels, span->array->ChanType);
1591 }
1592
1593 return rbPixels;
1594 }