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mesa: Convert colors if span ChanType and renderbuffer data type don't match
[mesa.git] / src / mesa / swrast / s_span.c
1 /*
2 * Mesa 3-D graphics library
3 * Version: 7.5
4 *
5 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
6 * Copyright (C) 2009 VMware, Inc. All Rights Reserved.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included
16 * in all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
22 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23 * CONNECTION WITH THE SOFTWARE OR THE USE OR 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
42 #include "s_atifragshader.h"
43 #include "s_alpha.h"
44 #include "s_blend.h"
45 #include "s_context.h"
46 #include "s_depth.h"
47 #include "s_fog.h"
48 #include "s_logic.h"
49 #include "s_masking.h"
50 #include "s_fragprog.h"
51 #include "s_span.h"
52 #include "s_stencil.h"
53 #include "s_texcombine.h"
54
55 #include <stdbool.h>
56
57 /**
58 * Set default fragment attributes for the span using the
59 * current raster values. Used prior to glDraw/CopyPixels
60 * and glBitmap.
61 */
62 void
63 _swrast_span_default_attribs(struct gl_context *ctx, SWspan *span)
64 {
65 GLchan r, g, b, a;
66 /* Z*/
67 {
68 const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;
69 if (ctx->DrawBuffer->Visual.depthBits <= 16)
70 span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);
71 else {
72 GLfloat tmpf = ctx->Current.RasterPos[2] * depthMax;
73 tmpf = MIN2(tmpf, depthMax);
74 span->z = (GLint)tmpf;
75 }
76 span->zStep = 0;
77 span->interpMask |= SPAN_Z;
78 }
79
80 /* W (for perspective correction) */
81 span->attrStart[FRAG_ATTRIB_WPOS][3] = 1.0;
82 span->attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0;
83 span->attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0;
84
85 /* primary color, or color index */
86 UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);
87 UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);
88 UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);
89 UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);
90 #if CHAN_TYPE == GL_FLOAT
91 span->red = r;
92 span->green = g;
93 span->blue = b;
94 span->alpha = a;
95 #else
96 span->red = IntToFixed(r);
97 span->green = IntToFixed(g);
98 span->blue = IntToFixed(b);
99 span->alpha = IntToFixed(a);
100 #endif
101 span->redStep = 0;
102 span->greenStep = 0;
103 span->blueStep = 0;
104 span->alphaStep = 0;
105 span->interpMask |= SPAN_RGBA;
106
107 COPY_4V(span->attrStart[FRAG_ATTRIB_COL0], ctx->Current.RasterColor);
108 ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
109 ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
110
111 /* Secondary color */
112 if (ctx->Light.Enabled || ctx->Fog.ColorSumEnabled)
113 {
114 COPY_4V(span->attrStart[FRAG_ATTRIB_COL1], ctx->Current.RasterSecondaryColor);
115 ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
116 ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
117 }
118
119 /* fog */
120 {
121 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
122 GLfloat fogVal; /* a coord or a blend factor */
123 if (swrast->_PreferPixelFog) {
124 /* fog blend factors will be computed from fog coordinates per pixel */
125 fogVal = ctx->Current.RasterDistance;
126 }
127 else {
128 /* fog blend factor should be computed from fogcoord now */
129 fogVal = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);
130 }
131 span->attrStart[FRAG_ATTRIB_FOGC][0] = fogVal;
132 span->attrStepX[FRAG_ATTRIB_FOGC][0] = 0.0;
133 span->attrStepY[FRAG_ATTRIB_FOGC][0] = 0.0;
134 }
135
136 /* texcoords */
137 {
138 GLuint i;
139 for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
140 const GLuint attr = FRAG_ATTRIB_TEX0 + i;
141 const GLfloat *tc = ctx->Current.RasterTexCoords[i];
142 if (_swrast_use_fragment_program(ctx) ||
143 ctx->ATIFragmentShader._Enabled) {
144 COPY_4V(span->attrStart[attr], tc);
145 }
146 else if (tc[3] > 0.0F) {
147 /* use (s/q, t/q, r/q, 1) */
148 span->attrStart[attr][0] = tc[0] / tc[3];
149 span->attrStart[attr][1] = tc[1] / tc[3];
150 span->attrStart[attr][2] = tc[2] / tc[3];
151 span->attrStart[attr][3] = 1.0;
152 }
153 else {
154 ASSIGN_4V(span->attrStart[attr], 0.0F, 0.0F, 0.0F, 1.0F);
155 }
156 ASSIGN_4V(span->attrStepX[attr], 0.0F, 0.0F, 0.0F, 0.0F);
157 ASSIGN_4V(span->attrStepY[attr], 0.0F, 0.0F, 0.0F, 0.0F);
158 }
159 }
160 }
161
162
163 /**
164 * Interpolate the active attributes (and'd with attrMask) to
165 * fill in span->array->attribs[].
166 * Perspective correction will be done. The point/line/triangle function
167 * should have computed attrStart/Step values for FRAG_ATTRIB_WPOS[3]!
168 */
169 static inline void
170 interpolate_active_attribs(struct gl_context *ctx, SWspan *span,
171 GLbitfield64 attrMask)
172 {
173 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
174
175 /*
176 * Don't overwrite existing array values, such as colors that may have
177 * been produced by glDraw/CopyPixels.
178 */
179 attrMask &= ~span->arrayAttribs;
180
181 ATTRIB_LOOP_BEGIN
182 if (attrMask & BITFIELD64_BIT(attr)) {
183 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
184 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3];
185 const GLfloat dv0dx = span->attrStepX[attr][0];
186 const GLfloat dv1dx = span->attrStepX[attr][1];
187 const GLfloat dv2dx = span->attrStepX[attr][2];
188 const GLfloat dv3dx = span->attrStepX[attr][3];
189 GLfloat v0 = span->attrStart[attr][0] + span->leftClip * dv0dx;
190 GLfloat v1 = span->attrStart[attr][1] + span->leftClip * dv1dx;
191 GLfloat v2 = span->attrStart[attr][2] + span->leftClip * dv2dx;
192 GLfloat v3 = span->attrStart[attr][3] + span->leftClip * dv3dx;
193 GLuint k;
194 for (k = 0; k < span->end; k++) {
195 const GLfloat invW = 1.0f / w;
196 span->array->attribs[attr][k][0] = v0 * invW;
197 span->array->attribs[attr][k][1] = v1 * invW;
198 span->array->attribs[attr][k][2] = v2 * invW;
199 span->array->attribs[attr][k][3] = v3 * invW;
200 v0 += dv0dx;
201 v1 += dv1dx;
202 v2 += dv2dx;
203 v3 += dv3dx;
204 w += dwdx;
205 }
206 ASSERT((span->arrayAttribs & BITFIELD64_BIT(attr)) == 0);
207 span->arrayAttribs |= BITFIELD64_BIT(attr);
208 }
209 ATTRIB_LOOP_END
210 }
211
212
213 /**
214 * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
215 * color array.
216 */
217 static inline void
218 interpolate_int_colors(struct gl_context *ctx, SWspan *span)
219 {
220 #if CHAN_BITS != 32
221 const GLuint n = span->end;
222 GLuint i;
223
224 ASSERT(!(span->arrayMask & SPAN_RGBA));
225 #endif
226
227 switch (span->array->ChanType) {
228 #if CHAN_BITS != 32
229 case GL_UNSIGNED_BYTE:
230 {
231 GLubyte (*rgba)[4] = span->array->rgba8;
232 if (span->interpMask & SPAN_FLAT) {
233 GLubyte color[4];
234 color[RCOMP] = FixedToInt(span->red);
235 color[GCOMP] = FixedToInt(span->green);
236 color[BCOMP] = FixedToInt(span->blue);
237 color[ACOMP] = FixedToInt(span->alpha);
238 for (i = 0; i < n; i++) {
239 COPY_4UBV(rgba[i], color);
240 }
241 }
242 else {
243 GLfixed r = span->red;
244 GLfixed g = span->green;
245 GLfixed b = span->blue;
246 GLfixed a = span->alpha;
247 GLint dr = span->redStep;
248 GLint dg = span->greenStep;
249 GLint db = span->blueStep;
250 GLint da = span->alphaStep;
251 for (i = 0; i < n; i++) {
252 rgba[i][RCOMP] = FixedToChan(r);
253 rgba[i][GCOMP] = FixedToChan(g);
254 rgba[i][BCOMP] = FixedToChan(b);
255 rgba[i][ACOMP] = FixedToChan(a);
256 r += dr;
257 g += dg;
258 b += db;
259 a += da;
260 }
261 }
262 }
263 break;
264 case GL_UNSIGNED_SHORT:
265 {
266 GLushort (*rgba)[4] = span->array->rgba16;
267 if (span->interpMask & SPAN_FLAT) {
268 GLushort color[4];
269 color[RCOMP] = FixedToInt(span->red);
270 color[GCOMP] = FixedToInt(span->green);
271 color[BCOMP] = FixedToInt(span->blue);
272 color[ACOMP] = FixedToInt(span->alpha);
273 for (i = 0; i < n; i++) {
274 COPY_4V(rgba[i], color);
275 }
276 }
277 else {
278 GLushort (*rgba)[4] = span->array->rgba16;
279 GLfixed r, g, b, a;
280 GLint dr, dg, db, da;
281 r = span->red;
282 g = span->green;
283 b = span->blue;
284 a = span->alpha;
285 dr = span->redStep;
286 dg = span->greenStep;
287 db = span->blueStep;
288 da = span->alphaStep;
289 for (i = 0; i < n; i++) {
290 rgba[i][RCOMP] = FixedToChan(r);
291 rgba[i][GCOMP] = FixedToChan(g);
292 rgba[i][BCOMP] = FixedToChan(b);
293 rgba[i][ACOMP] = FixedToChan(a);
294 r += dr;
295 g += dg;
296 b += db;
297 a += da;
298 }
299 }
300 }
301 break;
302 #endif
303 case GL_FLOAT:
304 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
305 break;
306 default:
307 _mesa_problem(ctx, "bad datatype 0x%x in interpolate_int_colors",
308 span->array->ChanType);
309 }
310 span->arrayMask |= SPAN_RGBA;
311 }
312
313
314 /**
315 * Populate the FRAG_ATTRIB_COL0 array.
316 */
317 static inline void
318 interpolate_float_colors(SWspan *span)
319 {
320 GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
321 const GLuint n = span->end;
322 GLuint i;
323
324 assert(!(span->arrayAttribs & FRAG_BIT_COL0));
325
326 if (span->arrayMask & SPAN_RGBA) {
327 /* convert array of int colors */
328 for (i = 0; i < n; i++) {
329 col0[i][0] = UBYTE_TO_FLOAT(span->array->rgba8[i][0]);
330 col0[i][1] = UBYTE_TO_FLOAT(span->array->rgba8[i][1]);
331 col0[i][2] = UBYTE_TO_FLOAT(span->array->rgba8[i][2]);
332 col0[i][3] = UBYTE_TO_FLOAT(span->array->rgba8[i][3]);
333 }
334 }
335 else {
336 /* interpolate red/green/blue/alpha to get float colors */
337 ASSERT(span->interpMask & SPAN_RGBA);
338 if (span->interpMask & SPAN_FLAT) {
339 GLfloat r = FixedToFloat(span->red);
340 GLfloat g = FixedToFloat(span->green);
341 GLfloat b = FixedToFloat(span->blue);
342 GLfloat a = FixedToFloat(span->alpha);
343 for (i = 0; i < n; i++) {
344 ASSIGN_4V(col0[i], r, g, b, a);
345 }
346 }
347 else {
348 GLfloat r = FixedToFloat(span->red);
349 GLfloat g = FixedToFloat(span->green);
350 GLfloat b = FixedToFloat(span->blue);
351 GLfloat a = FixedToFloat(span->alpha);
352 GLfloat dr = FixedToFloat(span->redStep);
353 GLfloat dg = FixedToFloat(span->greenStep);
354 GLfloat db = FixedToFloat(span->blueStep);
355 GLfloat da = FixedToFloat(span->alphaStep);
356 for (i = 0; i < n; i++) {
357 col0[i][0] = r;
358 col0[i][1] = g;
359 col0[i][2] = b;
360 col0[i][3] = a;
361 r += dr;
362 g += dg;
363 b += db;
364 a += da;
365 }
366 }
367 }
368
369 span->arrayAttribs |= FRAG_BIT_COL0;
370 span->array->ChanType = GL_FLOAT;
371 }
372
373
374
375 /**
376 * Fill in the span.zArray array from the span->z, zStep values.
377 */
378 void
379 _swrast_span_interpolate_z( const struct gl_context *ctx, SWspan *span )
380 {
381 const GLuint n = span->end;
382 GLuint i;
383
384 ASSERT(!(span->arrayMask & SPAN_Z));
385
386 if (ctx->DrawBuffer->Visual.depthBits <= 16) {
387 GLfixed zval = span->z;
388 GLuint *z = span->array->z;
389 for (i = 0; i < n; i++) {
390 z[i] = FixedToInt(zval);
391 zval += span->zStep;
392 }
393 }
394 else {
395 /* Deep Z buffer, no fixed->int shift */
396 GLuint zval = span->z;
397 GLuint *z = span->array->z;
398 for (i = 0; i < n; i++) {
399 z[i] = zval;
400 zval += span->zStep;
401 }
402 }
403 span->interpMask &= ~SPAN_Z;
404 span->arrayMask |= SPAN_Z;
405 }
406
407
408 /**
409 * Compute mipmap LOD from partial derivatives.
410 * This the ideal solution, as given in the OpenGL spec.
411 */
412 GLfloat
413 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
414 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
415 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
416 {
417 GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);
418 GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);
419 GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);
420 GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);
421 GLfloat x = SQRTF(dudx * dudx + dvdx * dvdx);
422 GLfloat y = SQRTF(dudy * dudy + dvdy * dvdy);
423 GLfloat rho = MAX2(x, y);
424 GLfloat lambda = LOG2(rho);
425 return lambda;
426 }
427
428
429 /**
430 * Compute mipmap LOD from partial derivatives.
431 * This is a faster approximation than above function.
432 */
433 #if 0
434 GLfloat
435 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
436 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
437 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
438 {
439 GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;
440 GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;
441 GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;
442 GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;
443 GLfloat maxU, maxV, rho, lambda;
444 dsdx2 = FABSF(dsdx2);
445 dsdy2 = FABSF(dsdy2);
446 dtdx2 = FABSF(dtdx2);
447 dtdy2 = FABSF(dtdy2);
448 maxU = MAX2(dsdx2, dsdy2) * texW;
449 maxV = MAX2(dtdx2, dtdy2) * texH;
450 rho = MAX2(maxU, maxV);
451 lambda = LOG2(rho);
452 return lambda;
453 }
454 #endif
455
456
457 /**
458 * Fill in the span.array->attrib[FRAG_ATTRIB_TEXn] arrays from the
459 * using the attrStart/Step values.
460 *
461 * This function only used during fixed-function fragment processing.
462 *
463 * Note: in the places where we divide by Q (or mult by invQ) we're
464 * really doing two things: perspective correction and texcoord
465 * projection. Remember, for texcoord (s,t,r,q) we need to index
466 * texels with (s/q, t/q, r/q).
467 */
468 static void
469 interpolate_texcoords(struct gl_context *ctx, SWspan *span)
470 {
471 const GLuint maxUnit
472 = (ctx->Texture._EnabledCoordUnits > 1) ? ctx->Const.MaxTextureUnits : 1;
473 GLuint u;
474
475 /* XXX CoordUnits vs. ImageUnits */
476 for (u = 0; u < maxUnit; u++) {
477 if (ctx->Texture._EnabledCoordUnits & (1 << u)) {
478 const GLuint attr = FRAG_ATTRIB_TEX0 + u;
479 const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
480 GLfloat texW, texH;
481 GLboolean needLambda;
482 GLfloat (*texcoord)[4] = span->array->attribs[attr];
483 GLfloat *lambda = span->array->lambda[u];
484 const GLfloat dsdx = span->attrStepX[attr][0];
485 const GLfloat dsdy = span->attrStepY[attr][0];
486 const GLfloat dtdx = span->attrStepX[attr][1];
487 const GLfloat dtdy = span->attrStepY[attr][1];
488 const GLfloat drdx = span->attrStepX[attr][2];
489 const GLfloat dqdx = span->attrStepX[attr][3];
490 const GLfloat dqdy = span->attrStepY[attr][3];
491 GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx;
492 GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx;
493 GLfloat r = span->attrStart[attr][2] + span->leftClip * drdx;
494 GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx;
495
496 if (obj) {
497 const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel];
498 const struct swrast_texture_image *swImg =
499 swrast_texture_image_const(img);
500
501 needLambda = (obj->Sampler.MinFilter != obj->Sampler.MagFilter)
502 || _swrast_use_fragment_program(ctx);
503 /* LOD is calculated directly in the ansiotropic filter, we can
504 * skip the normal lambda function as the result is ignored.
505 */
506 if (obj->Sampler.MaxAnisotropy > 1.0 &&
507 obj->Sampler.MinFilter == GL_LINEAR_MIPMAP_LINEAR) {
508 needLambda = GL_FALSE;
509 }
510 texW = swImg->WidthScale;
511 texH = swImg->HeightScale;
512 }
513 else {
514 /* using a fragment program */
515 texW = 1.0;
516 texH = 1.0;
517 needLambda = GL_FALSE;
518 }
519
520 if (needLambda) {
521 GLuint i;
522 if (_swrast_use_fragment_program(ctx)
523 || ctx->ATIFragmentShader._Enabled) {
524 /* do perspective correction but don't divide s, t, r by q */
525 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
526 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
527 for (i = 0; i < span->end; i++) {
528 const GLfloat invW = 1.0F / w;
529 texcoord[i][0] = s * invW;
530 texcoord[i][1] = t * invW;
531 texcoord[i][2] = r * invW;
532 texcoord[i][3] = q * invW;
533 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
534 dqdx, dqdy, texW, texH,
535 s, t, q, invW);
536 s += dsdx;
537 t += dtdx;
538 r += drdx;
539 q += dqdx;
540 w += dwdx;
541 }
542 }
543 else {
544 for (i = 0; i < span->end; i++) {
545 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
546 texcoord[i][0] = s * invQ;
547 texcoord[i][1] = t * invQ;
548 texcoord[i][2] = r * invQ;
549 texcoord[i][3] = q;
550 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
551 dqdx, dqdy, texW, texH,
552 s, t, q, invQ);
553 s += dsdx;
554 t += dtdx;
555 r += drdx;
556 q += dqdx;
557 }
558 }
559 span->arrayMask |= SPAN_LAMBDA;
560 }
561 else {
562 GLuint i;
563 if (_swrast_use_fragment_program(ctx) ||
564 ctx->ATIFragmentShader._Enabled) {
565 /* do perspective correction but don't divide s, t, r by q */
566 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
567 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
568 for (i = 0; i < span->end; i++) {
569 const GLfloat invW = 1.0F / w;
570 texcoord[i][0] = s * invW;
571 texcoord[i][1] = t * invW;
572 texcoord[i][2] = r * invW;
573 texcoord[i][3] = q * invW;
574 lambda[i] = 0.0;
575 s += dsdx;
576 t += dtdx;
577 r += drdx;
578 q += dqdx;
579 w += dwdx;
580 }
581 }
582 else if (dqdx == 0.0F) {
583 /* Ortho projection or polygon's parallel to window X axis */
584 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
585 for (i = 0; i < span->end; i++) {
586 texcoord[i][0] = s * invQ;
587 texcoord[i][1] = t * invQ;
588 texcoord[i][2] = r * invQ;
589 texcoord[i][3] = q;
590 lambda[i] = 0.0;
591 s += dsdx;
592 t += dtdx;
593 r += drdx;
594 }
595 }
596 else {
597 for (i = 0; i < span->end; i++) {
598 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
599 texcoord[i][0] = s * invQ;
600 texcoord[i][1] = t * invQ;
601 texcoord[i][2] = r * invQ;
602 texcoord[i][3] = q;
603 lambda[i] = 0.0;
604 s += dsdx;
605 t += dtdx;
606 r += drdx;
607 q += dqdx;
608 }
609 }
610 } /* lambda */
611 } /* if */
612 } /* for */
613 }
614
615
616 /**
617 * Fill in the arrays->attribs[FRAG_ATTRIB_WPOS] array.
618 */
619 static inline void
620 interpolate_wpos(struct gl_context *ctx, SWspan *span)
621 {
622 GLfloat (*wpos)[4] = span->array->attribs[FRAG_ATTRIB_WPOS];
623 GLuint i;
624 const GLfloat zScale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
625 GLfloat w, dw;
626
627 if (span->arrayMask & SPAN_XY) {
628 for (i = 0; i < span->end; i++) {
629 wpos[i][0] = (GLfloat) span->array->x[i];
630 wpos[i][1] = (GLfloat) span->array->y[i];
631 }
632 }
633 else {
634 for (i = 0; i < span->end; i++) {
635 wpos[i][0] = (GLfloat) span->x + i;
636 wpos[i][1] = (GLfloat) span->y;
637 }
638 }
639
640 dw = span->attrStepX[FRAG_ATTRIB_WPOS][3];
641 w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dw;
642 for (i = 0; i < span->end; i++) {
643 wpos[i][2] = (GLfloat) span->array->z[i] * zScale;
644 wpos[i][3] = w;
645 w += dw;
646 }
647 }
648
649
650 /**
651 * Apply the current polygon stipple pattern to a span of pixels.
652 */
653 static inline void
654 stipple_polygon_span(struct gl_context *ctx, SWspan *span)
655 {
656 GLubyte *mask = span->array->mask;
657
658 ASSERT(ctx->Polygon.StippleFlag);
659
660 if (span->arrayMask & SPAN_XY) {
661 /* arrays of x/y pixel coords */
662 GLuint i;
663 for (i = 0; i < span->end; i++) {
664 const GLint col = span->array->x[i] % 32;
665 const GLint row = span->array->y[i] % 32;
666 const GLuint stipple = ctx->PolygonStipple[row];
667 if (((1 << col) & stipple) == 0) {
668 mask[i] = 0;
669 }
670 }
671 }
672 else {
673 /* horizontal span of pixels */
674 const GLuint highBit = 1 << 31;
675 const GLuint stipple = ctx->PolygonStipple[span->y % 32];
676 GLuint i, m = highBit >> (GLuint) (span->x % 32);
677 for (i = 0; i < span->end; i++) {
678 if ((m & stipple) == 0) {
679 mask[i] = 0;
680 }
681 m = m >> 1;
682 if (m == 0) {
683 m = highBit;
684 }
685 }
686 }
687 span->writeAll = GL_FALSE;
688 }
689
690
691 /**
692 * Clip a pixel span to the current buffer/window boundaries:
693 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
694 * window clipping and scissoring.
695 * Return: GL_TRUE some pixels still visible
696 * GL_FALSE nothing visible
697 */
698 static inline GLuint
699 clip_span( struct gl_context *ctx, SWspan *span )
700 {
701 const GLint xmin = ctx->DrawBuffer->_Xmin;
702 const GLint xmax = ctx->DrawBuffer->_Xmax;
703 const GLint ymin = ctx->DrawBuffer->_Ymin;
704 const GLint ymax = ctx->DrawBuffer->_Ymax;
705
706 span->leftClip = 0;
707
708 if (span->arrayMask & SPAN_XY) {
709 /* arrays of x/y pixel coords */
710 const GLint *x = span->array->x;
711 const GLint *y = span->array->y;
712 const GLint n = span->end;
713 GLubyte *mask = span->array->mask;
714 GLint i;
715 GLuint passed = 0;
716 if (span->arrayMask & SPAN_MASK) {
717 /* note: using & intead of && to reduce branches */
718 for (i = 0; i < n; i++) {
719 mask[i] &= (x[i] >= xmin) & (x[i] < xmax)
720 & (y[i] >= ymin) & (y[i] < ymax);
721 passed += mask[i];
722 }
723 }
724 else {
725 /* note: using & intead of && to reduce branches */
726 for (i = 0; i < n; i++) {
727 mask[i] = (x[i] >= xmin) & (x[i] < xmax)
728 & (y[i] >= ymin) & (y[i] < ymax);
729 passed += mask[i];
730 }
731 }
732 return passed > 0;
733 }
734 else {
735 /* horizontal span of pixels */
736 const GLint x = span->x;
737 const GLint y = span->y;
738 GLint n = span->end;
739
740 /* Trivial rejection tests */
741 if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {
742 span->end = 0;
743 return GL_FALSE; /* all pixels clipped */
744 }
745
746 /* Clip to right */
747 if (x + n > xmax) {
748 ASSERT(x < xmax);
749 n = span->end = xmax - x;
750 }
751
752 /* Clip to the left */
753 if (x < xmin) {
754 const GLint leftClip = xmin - x;
755 GLuint i;
756
757 ASSERT(leftClip > 0);
758 ASSERT(x + n > xmin);
759
760 /* Clip 'leftClip' pixels from the left side.
761 * The span->leftClip field will be applied when we interpolate
762 * fragment attributes.
763 * For arrays of values, shift them left.
764 */
765 for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
766 if (span->interpMask & (1 << i)) {
767 GLuint j;
768 for (j = 0; j < 4; j++) {
769 span->attrStart[i][j] += leftClip * span->attrStepX[i][j];
770 }
771 }
772 }
773
774 span->red += leftClip * span->redStep;
775 span->green += leftClip * span->greenStep;
776 span->blue += leftClip * span->blueStep;
777 span->alpha += leftClip * span->alphaStep;
778 span->index += leftClip * span->indexStep;
779 span->z += leftClip * span->zStep;
780 span->intTex[0] += leftClip * span->intTexStep[0];
781 span->intTex[1] += leftClip * span->intTexStep[1];
782
783 #define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
784 memmove(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
785
786 for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
787 if (span->arrayAttribs & (1 << i)) {
788 /* shift array elements left by 'leftClip' */
789 SHIFT_ARRAY(span->array->attribs[i], leftClip, n - leftClip);
790 }
791 }
792
793 SHIFT_ARRAY(span->array->mask, leftClip, n - leftClip);
794 SHIFT_ARRAY(span->array->rgba8, leftClip, n - leftClip);
795 SHIFT_ARRAY(span->array->rgba16, leftClip, n - leftClip);
796 SHIFT_ARRAY(span->array->x, leftClip, n - leftClip);
797 SHIFT_ARRAY(span->array->y, leftClip, n - leftClip);
798 SHIFT_ARRAY(span->array->z, leftClip, n - leftClip);
799 SHIFT_ARRAY(span->array->index, leftClip, n - leftClip);
800 for (i = 0; i < MAX_TEXTURE_COORD_UNITS; i++) {
801 SHIFT_ARRAY(span->array->lambda[i], leftClip, n - leftClip);
802 }
803 SHIFT_ARRAY(span->array->coverage, leftClip, n - leftClip);
804
805 #undef SHIFT_ARRAY
806
807 span->leftClip = leftClip;
808 span->x = xmin;
809 span->end -= leftClip;
810 span->writeAll = GL_FALSE;
811 }
812
813 ASSERT(span->x >= xmin);
814 ASSERT(span->x + span->end <= xmax);
815 ASSERT(span->y >= ymin);
816 ASSERT(span->y < ymax);
817
818 return GL_TRUE; /* some pixels visible */
819 }
820 }
821
822
823 /**
824 * Add specular colors to primary colors.
825 * Only called during fixed-function operation.
826 * Result is float color array (FRAG_ATTRIB_COL0).
827 */
828 static inline void
829 add_specular(struct gl_context *ctx, SWspan *span)
830 {
831 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
832 const GLubyte *mask = span->array->mask;
833 GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
834 GLfloat (*col1)[4] = span->array->attribs[FRAG_ATTRIB_COL1];
835 GLuint i;
836
837 ASSERT(!_swrast_use_fragment_program(ctx));
838 ASSERT(span->arrayMask & SPAN_RGBA);
839 ASSERT(swrast->_ActiveAttribMask & FRAG_BIT_COL1);
840 (void) swrast; /* silence warning */
841
842 if (span->array->ChanType == GL_FLOAT) {
843 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
844 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
845 }
846 }
847 else {
848 /* need float colors */
849 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
850 interpolate_float_colors(span);
851 }
852 }
853
854 if ((span->arrayAttribs & FRAG_BIT_COL1) == 0) {
855 /* XXX could avoid this and interpolate COL1 in the loop below */
856 interpolate_active_attribs(ctx, span, FRAG_BIT_COL1);
857 }
858
859 ASSERT(span->arrayAttribs & FRAG_BIT_COL0);
860 ASSERT(span->arrayAttribs & FRAG_BIT_COL1);
861
862 for (i = 0; i < span->end; i++) {
863 if (mask[i]) {
864 col0[i][0] += col1[i][0];
865 col0[i][1] += col1[i][1];
866 col0[i][2] += col1[i][2];
867 }
868 }
869
870 span->array->ChanType = GL_FLOAT;
871 }
872
873
874 /**
875 * Apply antialiasing coverage value to alpha values.
876 */
877 static inline void
878 apply_aa_coverage(SWspan *span)
879 {
880 const GLfloat *coverage = span->array->coverage;
881 GLuint i;
882 if (span->array->ChanType == GL_UNSIGNED_BYTE) {
883 GLubyte (*rgba)[4] = span->array->rgba8;
884 for (i = 0; i < span->end; i++) {
885 const GLfloat a = rgba[i][ACOMP] * coverage[i];
886 rgba[i][ACOMP] = (GLubyte) CLAMP(a, 0.0, 255.0);
887 ASSERT(coverage[i] >= 0.0);
888 ASSERT(coverage[i] <= 1.0);
889 }
890 }
891 else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
892 GLushort (*rgba)[4] = span->array->rgba16;
893 for (i = 0; i < span->end; i++) {
894 const GLfloat a = rgba[i][ACOMP] * coverage[i];
895 rgba[i][ACOMP] = (GLushort) CLAMP(a, 0.0, 65535.0);
896 }
897 }
898 else {
899 GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
900 for (i = 0; i < span->end; i++) {
901 rgba[i][ACOMP] = rgba[i][ACOMP] * coverage[i];
902 /* clamp later */
903 }
904 }
905 }
906
907
908 /**
909 * Clamp span's float colors to [0,1]
910 */
911 static inline void
912 clamp_colors(SWspan *span)
913 {
914 GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
915 GLuint i;
916 ASSERT(span->array->ChanType == GL_FLOAT);
917 for (i = 0; i < span->end; i++) {
918 rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
919 rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
920 rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
921 rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
922 }
923 }
924
925
926 /**
927 * Convert the span's color arrays to the given type.
928 * The only way 'output' can be greater than zero is when we have a fragment
929 * program that writes to gl_FragData[1] or higher.
930 * \param output which fragment program color output is being processed
931 */
932 static inline void
933 convert_color_type(SWspan *span, GLenum newType, GLuint output)
934 {
935 GLvoid *src, *dst;
936
937 if (output > 0 || span->array->ChanType == GL_FLOAT) {
938 src = span->array->attribs[FRAG_ATTRIB_COL0 + output];
939 span->array->ChanType = GL_FLOAT;
940 }
941 else if (span->array->ChanType == GL_UNSIGNED_BYTE) {
942 src = span->array->rgba8;
943 }
944 else {
945 ASSERT(span->array->ChanType == GL_UNSIGNED_SHORT);
946 src = span->array->rgba16;
947 }
948
949 if (newType == GL_UNSIGNED_BYTE) {
950 dst = span->array->rgba8;
951 }
952 else if (newType == GL_UNSIGNED_SHORT) {
953 dst = span->array->rgba16;
954 }
955 else {
956 dst = span->array->attribs[FRAG_ATTRIB_COL0];
957 }
958
959 _mesa_convert_colors(span->array->ChanType, src,
960 newType, dst,
961 span->end, span->array->mask);
962
963 span->array->ChanType = newType;
964 span->array->rgba = dst;
965 }
966
967
968
969 /**
970 * Apply fragment shader, fragment program or normal texturing to span.
971 */
972 static inline void
973 shade_texture_span(struct gl_context *ctx, SWspan *span)
974 {
975 if (_swrast_use_fragment_program(ctx) ||
976 ctx->ATIFragmentShader._Enabled) {
977 /* programmable shading */
978 if (span->primitive == GL_BITMAP && span->array->ChanType != GL_FLOAT) {
979 convert_color_type(span, GL_FLOAT, 0);
980 }
981 else {
982 span->array->rgba = (void *) span->array->attribs[FRAG_ATTRIB_COL0];
983 }
984
985 if (span->primitive != GL_POINT ||
986 (span->interpMask & SPAN_RGBA) ||
987 ctx->Point.PointSprite) {
988 /* for single-pixel points, we populated the arrays already */
989 interpolate_active_attribs(ctx, span, ~0);
990 }
991 span->array->ChanType = GL_FLOAT;
992
993 if (!(span->arrayMask & SPAN_Z))
994 _swrast_span_interpolate_z (ctx, span);
995
996 #if 0
997 if (inputsRead & FRAG_BIT_WPOS)
998 #else
999 /* XXX always interpolate wpos so that DDX/DDY work */
1000 #endif
1001 interpolate_wpos(ctx, span);
1002
1003 /* Run fragment program/shader now */
1004 if (_swrast_use_fragment_program(ctx)) {
1005 _swrast_exec_fragment_program(ctx, span);
1006 }
1007 else {
1008 ASSERT(ctx->ATIFragmentShader._Enabled);
1009 _swrast_exec_fragment_shader(ctx, span);
1010 }
1011 }
1012 else if (ctx->Texture._EnabledCoordUnits) {
1013 /* conventional texturing */
1014
1015 #if CHAN_BITS == 32
1016 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
1017 interpolate_int_colors(ctx, span);
1018 }
1019 #else
1020 if (!(span->arrayMask & SPAN_RGBA))
1021 interpolate_int_colors(ctx, span);
1022 #endif
1023 if ((span->arrayAttribs & FRAG_BITS_TEX_ANY) == 0x0)
1024 interpolate_texcoords(ctx, span);
1025
1026 _swrast_texture_span(ctx, span);
1027 }
1028 }
1029
1030
1031 /** Put colors at x/y locations into a renderbuffer */
1032 static void
1033 put_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1034 GLenum datatype,
1035 GLuint count, const GLint x[], const GLint y[],
1036 const void *values, const GLubyte *mask)
1037 {
1038 gl_pack_ubyte_rgba_func pack_ubyte = NULL;
1039 gl_pack_float_rgba_func pack_float = NULL;
1040 GLuint i;
1041
1042 if (datatype == GL_UNSIGNED_BYTE)
1043 pack_ubyte = _mesa_get_pack_ubyte_rgba_function(rb->Format);
1044 else
1045 pack_float = _mesa_get_pack_float_rgba_function(rb->Format);
1046
1047 for (i = 0; i < count; i++) {
1048 if (mask[i]) {
1049 GLubyte *dst = _swrast_pixel_address(rb, x[i], y[i]);
1050
1051 if (datatype == GL_UNSIGNED_BYTE) {
1052 pack_ubyte((const GLubyte *) values + 4 * i, dst);
1053 }
1054 else {
1055 assert(datatype == GL_FLOAT);
1056 pack_float((const GLfloat *) values + 4 * i, dst);
1057 }
1058 }
1059 }
1060 }
1061
1062
1063 /** Put row of colors into renderbuffer */
1064 void
1065 _swrast_put_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1066 GLenum datatype,
1067 GLuint count, GLint x, GLint y,
1068 const void *values, const GLubyte *mask)
1069 {
1070 GLubyte *dst = _swrast_pixel_address(rb, x, y);
1071
1072 if (!mask) {
1073 if (datatype == GL_UNSIGNED_BYTE) {
1074 _mesa_pack_ubyte_rgba_row(rb->Format, count,
1075 (const GLubyte (*)[4]) values, dst);
1076 }
1077 else {
1078 assert(datatype == GL_FLOAT);
1079 _mesa_pack_float_rgba_row(rb->Format, count,
1080 (const GLfloat (*)[4]) values, dst);
1081 }
1082 }
1083 else {
1084 const GLuint bpp = _mesa_get_format_bytes(rb->Format);
1085 GLuint i, runLen, runStart;
1086 /* We can't pass a 'mask' array to the _mesa_pack_rgba_row() functions
1087 * so look for runs where mask=1...
1088 */
1089 runLen = runStart = 0;
1090 for (i = 0; i < count; i++) {
1091 if (mask[i]) {
1092 if (runLen == 0)
1093 runStart = i;
1094 runLen++;
1095 }
1096
1097 if (!mask[i] || i == count - 1) {
1098 /* might be the end of a run of pixels */
1099 if (runLen > 0) {
1100 if (datatype == GL_UNSIGNED_BYTE) {
1101 _mesa_pack_ubyte_rgba_row(rb->Format, runLen,
1102 (const GLubyte (*)[4]) values + runStart,
1103 dst + runStart * bpp);
1104 }
1105 else {
1106 assert(datatype == GL_FLOAT);
1107 _mesa_pack_float_rgba_row(rb->Format, runLen,
1108 (const GLfloat (*)[4]) values + runStart,
1109 dst + runStart * bpp);
1110 }
1111 runLen = 0;
1112 }
1113 }
1114 }
1115 }
1116 }
1117
1118
1119
1120 /**
1121 * Apply all the per-fragment operations to a span.
1122 * This now includes texturing (_swrast_write_texture_span() is history).
1123 * This function may modify any of the array values in the span.
1124 * span->interpMask and span->arrayMask may be changed but will be restored
1125 * to their original values before returning.
1126 */
1127 void
1128 _swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)
1129 {
1130 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
1131 const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;
1132 const GLbitfield origInterpMask = span->interpMask;
1133 const GLbitfield origArrayMask = span->arrayMask;
1134 const GLbitfield64 origArrayAttribs = span->arrayAttribs;
1135 const GLenum origChanType = span->array->ChanType;
1136 void * const origRgba = span->array->rgba;
1137 const GLboolean shader = (_swrast_use_fragment_program(ctx)
1138 || ctx->ATIFragmentShader._Enabled);
1139 const GLboolean shaderOrTexture = shader || ctx->Texture._EnabledCoordUnits;
1140 struct gl_framebuffer *fb = ctx->DrawBuffer;
1141
1142 /*
1143 printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__,
1144 span->interpMask, span->arrayMask);
1145 */
1146
1147 ASSERT(span->primitive == GL_POINT ||
1148 span->primitive == GL_LINE ||
1149 span->primitive == GL_POLYGON ||
1150 span->primitive == GL_BITMAP);
1151
1152 /* Fragment write masks */
1153 if (span->arrayMask & SPAN_MASK) {
1154 /* mask was initialized by caller, probably glBitmap */
1155 span->writeAll = GL_FALSE;
1156 }
1157 else {
1158 memset(span->array->mask, 1, span->end);
1159 span->writeAll = GL_TRUE;
1160 }
1161
1162 /* Clip to window/scissor box */
1163 if (!clip_span(ctx, span)) {
1164 return;
1165 }
1166
1167 ASSERT(span->end <= MAX_WIDTH);
1168
1169 /* Depth bounds test */
1170 if (ctx->Depth.BoundsTest && fb->Visual.depthBits > 0) {
1171 if (!_swrast_depth_bounds_test(ctx, span)) {
1172 return;
1173 }
1174 }
1175
1176 #ifdef DEBUG
1177 /* Make sure all fragments are within window bounds */
1178 if (span->arrayMask & SPAN_XY) {
1179 /* array of pixel locations */
1180 GLuint i;
1181 for (i = 0; i < span->end; i++) {
1182 if (span->array->mask[i]) {
1183 assert(span->array->x[i] >= fb->_Xmin);
1184 assert(span->array->x[i] < fb->_Xmax);
1185 assert(span->array->y[i] >= fb->_Ymin);
1186 assert(span->array->y[i] < fb->_Ymax);
1187 }
1188 }
1189 }
1190 #endif
1191
1192 /* Polygon Stippling */
1193 if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
1194 stipple_polygon_span(ctx, span);
1195 }
1196
1197 /* This is the normal place to compute the fragment color/Z
1198 * from texturing or shading.
1199 */
1200 if (shaderOrTexture && !swrast->_DeferredTexture) {
1201 shade_texture_span(ctx, span);
1202 }
1203
1204 /* Do the alpha test */
1205 if (ctx->Color.AlphaEnabled) {
1206 if (!_swrast_alpha_test(ctx, span)) {
1207 /* all fragments failed test */
1208 goto end;
1209 }
1210 }
1211
1212 /* Stencil and Z testing */
1213 if (ctx->Stencil._Enabled || ctx->Depth.Test) {
1214 if (!(span->arrayMask & SPAN_Z))
1215 _swrast_span_interpolate_z(ctx, span);
1216
1217 if (ctx->Transform.DepthClamp)
1218 _swrast_depth_clamp_span(ctx, span);
1219
1220 if (ctx->Stencil._Enabled) {
1221 /* Combined Z/stencil tests */
1222 if (!_swrast_stencil_and_ztest_span(ctx, span)) {
1223 /* all fragments failed test */
1224 goto end;
1225 }
1226 }
1227 else if (fb->Visual.depthBits > 0) {
1228 /* Just regular depth testing */
1229 ASSERT(ctx->Depth.Test);
1230 ASSERT(span->arrayMask & SPAN_Z);
1231 if (!_swrast_depth_test_span(ctx, span)) {
1232 /* all fragments failed test */
1233 goto end;
1234 }
1235 }
1236 }
1237
1238 if (ctx->Query.CurrentOcclusionObject) {
1239 /* update count of 'passed' fragments */
1240 struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
1241 GLuint i;
1242 for (i = 0; i < span->end; i++)
1243 q->Result += span->array->mask[i];
1244 }
1245
1246 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1247 * the occlusion test.
1248 */
1249 if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {
1250 /* no colors to write */
1251 goto end;
1252 }
1253
1254 /* If we were able to defer fragment color computation to now, there's
1255 * a good chance that many fragments will have already been killed by
1256 * Z/stencil testing.
1257 */
1258 if (shaderOrTexture && swrast->_DeferredTexture) {
1259 shade_texture_span(ctx, span);
1260 }
1261
1262 #if CHAN_BITS == 32
1263 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
1264 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
1265 }
1266 #else
1267 if ((span->arrayMask & SPAN_RGBA) == 0) {
1268 interpolate_int_colors(ctx, span);
1269 }
1270 #endif
1271
1272 ASSERT(span->arrayMask & SPAN_RGBA);
1273
1274 if (span->primitive == GL_BITMAP || !swrast->SpecularVertexAdd) {
1275 /* Add primary and specular (diffuse + specular) colors */
1276 if (!shader) {
1277 if (ctx->Fog.ColorSumEnabled ||
1278 (ctx->Light.Enabled &&
1279 ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {
1280 add_specular(ctx, span);
1281 }
1282 }
1283 }
1284
1285 /* Fog */
1286 if (swrast->_FogEnabled) {
1287 _swrast_fog_rgba_span(ctx, span);
1288 }
1289
1290 /* Antialias coverage application */
1291 if (span->arrayMask & SPAN_COVERAGE) {
1292 apply_aa_coverage(span);
1293 }
1294
1295 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1296 if (ctx->Color.ClampFragmentColor == GL_TRUE &&
1297 span->array->ChanType == GL_FLOAT) {
1298 clamp_colors(span);
1299 }
1300
1301 /*
1302 * Write to renderbuffers.
1303 * Depending on glDrawBuffer() state and the which color outputs are
1304 * written by the fragment shader, we may either replicate one color to
1305 * all renderbuffers or write a different color to each renderbuffer.
1306 * multiFragOutputs=TRUE for the later case.
1307 */
1308 {
1309 const GLuint numBuffers = fb->_NumColorDrawBuffers;
1310 const struct gl_fragment_program *fp = ctx->FragmentProgram._Current;
1311 const GLboolean multiFragOutputs =
1312 _swrast_use_fragment_program(ctx)
1313 && fp->Base.OutputsWritten >= (1 << FRAG_RESULT_DATA0);
1314 GLuint buf;
1315
1316 for (buf = 0; buf < numBuffers; buf++) {
1317 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];
1318
1319 /* color[fragOutput] will be written to buffer[buf] */
1320
1321 if (rb) {
1322 GLchan rgbaSave[MAX_WIDTH][4];
1323
1324 GLenum datatype;
1325 GLuint comps;
1326
1327 _mesa_format_to_type_and_comps(rb->Format, &datatype, &comps);
1328
1329 /* set span->array->rgba to colors for render buffer's datatype */
1330 if (datatype != span->array->ChanType) {
1331 convert_color_type(span, datatype, 0);
1332 }
1333 else {
1334 if (span->array->ChanType == GL_UNSIGNED_BYTE) {
1335 span->array->rgba = span->array->rgba8;
1336 }
1337 else {
1338 span->array->rgba = (void *)
1339 span->array->attribs[FRAG_ATTRIB_COL0];
1340 }
1341 }
1342
1343 if (!multiFragOutputs && numBuffers > 1) {
1344 /* save colors for second, third renderbuffer writes */
1345 memcpy(rgbaSave, span->array->rgba,
1346 4 * span->end * sizeof(GLchan));
1347 }
1348
1349 ASSERT(rb->_BaseFormat == GL_RGBA ||
1350 rb->_BaseFormat == GL_RGB ||
1351 rb->_BaseFormat == GL_RED ||
1352 rb->_BaseFormat == GL_RG ||
1353 rb->_BaseFormat == GL_ALPHA);
1354
1355 if (ctx->Color.ColorLogicOpEnabled) {
1356 _swrast_logicop_rgba_span(ctx, rb, span);
1357 }
1358 else if ((ctx->Color.BlendEnabled >> buf) & 1) {
1359 _swrast_blend_span(ctx, rb, span);
1360 }
1361
1362 if (colorMask[buf] != 0xffffffff) {
1363 _swrast_mask_rgba_span(ctx, rb, span, buf);
1364 }
1365
1366 if (span->arrayMask & SPAN_XY) {
1367 /* array of pixel coords */
1368 put_values(ctx, rb,
1369 span->array->ChanType, span->end,
1370 span->array->x, span->array->y,
1371 span->array->rgba, span->array->mask);
1372 }
1373 else {
1374 /* horizontal run of pixels */
1375 _swrast_put_row(ctx, rb,
1376 span->array->ChanType,
1377 span->end, span->x, span->y,
1378 span->array->rgba,
1379 span->writeAll ? NULL: span->array->mask);
1380 }
1381
1382 if (!multiFragOutputs && numBuffers > 1) {
1383 /* restore original span values */
1384 memcpy(span->array->rgba, rgbaSave,
1385 4 * span->end * sizeof(GLchan));
1386 }
1387
1388 } /* if rb */
1389 } /* for buf */
1390 }
1391
1392 end:
1393 /* restore these values before returning */
1394 span->interpMask = origInterpMask;
1395 span->arrayMask = origArrayMask;
1396 span->arrayAttribs = origArrayAttribs;
1397 span->array->ChanType = origChanType;
1398 span->array->rgba = origRgba;
1399 }
1400
1401
1402 /**
1403 * Read float RGBA pixels from a renderbuffer. Clipping will be done to
1404 * prevent reading ouside the buffer's boundaries.
1405 * \param rgba the returned colors
1406 */
1407 void
1408 _swrast_read_rgba_span( struct gl_context *ctx, struct gl_renderbuffer *rb,
1409 GLuint n, GLint x, GLint y,
1410 GLvoid *rgba)
1411 {
1412 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
1413 GLenum dstType = GL_FLOAT;
1414 const GLint bufWidth = (GLint) rb->Width;
1415 const GLint bufHeight = (GLint) rb->Height;
1416
1417 if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
1418 /* completely above, below, or right */
1419 /* XXX maybe leave rgba values undefined? */
1420 memset(rgba, 0, 4 * n * sizeof(GLchan));
1421 }
1422 else {
1423 GLint skip, length;
1424 GLubyte *src;
1425
1426 if (x < 0) {
1427 /* left edge clipping */
1428 skip = -x;
1429 length = (GLint) n - skip;
1430 if (length < 0) {
1431 /* completely left of window */
1432 return;
1433 }
1434 if (length > bufWidth) {
1435 length = bufWidth;
1436 }
1437 }
1438 else if ((GLint) (x + n) > bufWidth) {
1439 /* right edge clipping */
1440 skip = 0;
1441 length = bufWidth - x;
1442 if (length < 0) {
1443 /* completely to right of window */
1444 return;
1445 }
1446 }
1447 else {
1448 /* no clipping */
1449 skip = 0;
1450 length = (GLint) n;
1451 }
1452
1453 ASSERT(rb);
1454 ASSERT(rb->_BaseFormat == GL_RGBA ||
1455 rb->_BaseFormat == GL_RGB ||
1456 rb->_BaseFormat == GL_RG ||
1457 rb->_BaseFormat == GL_RED ||
1458 rb->_BaseFormat == GL_LUMINANCE ||
1459 rb->_BaseFormat == GL_INTENSITY ||
1460 rb->_BaseFormat == GL_LUMINANCE_ALPHA ||
1461 rb->_BaseFormat == GL_ALPHA);
1462
1463 assert(srb->Map);
1464
1465 src = _swrast_pixel_address(rb, x + skip, y);
1466
1467 if (dstType == GL_UNSIGNED_BYTE) {
1468 _mesa_unpack_ubyte_rgba_row(rb->Format, length, src,
1469 (GLubyte (*)[4]) rgba + skip);
1470 }
1471 else if (dstType == GL_FLOAT) {
1472 _mesa_unpack_rgba_row(rb->Format, length, src,
1473 (GLfloat (*)[4]) rgba + skip);
1474 }
1475 else {
1476 _mesa_problem(ctx, "unexpected type in _swrast_read_rgba_span()");
1477 }
1478 }
1479 }
1480
1481
1482 /**
1483 * Get colors at x/y positions with clipping.
1484 * \param type type of values to return
1485 */
1486 static void
1487 get_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1488 GLuint count, const GLint x[], const GLint y[],
1489 void *values, GLenum type)
1490 {
1491 GLuint i;
1492
1493 for (i = 0; i < count; i++) {
1494 if (x[i] >= 0 && y[i] >= 0 &&
1495 x[i] < (GLint) rb->Width && y[i] < (GLint) rb->Height) {
1496 /* inside */
1497 const GLubyte *src = _swrast_pixel_address(rb, x[i], y[i]);
1498
1499 if (type == GL_UNSIGNED_BYTE) {
1500 _mesa_unpack_ubyte_rgba_row(rb->Format, 1, src,
1501 (GLubyte (*)[4]) values + i);
1502 }
1503 else if (type == GL_FLOAT) {
1504 _mesa_unpack_rgba_row(rb->Format, 1, src,
1505 (GLfloat (*)[4]) values + i);
1506 }
1507 else {
1508 _mesa_problem(ctx, "unexpected type in get_values()");
1509 }
1510 }
1511 }
1512 }
1513
1514
1515 /**
1516 * Get row of colors with clipping.
1517 * \param type type of values to return
1518 */
1519 static void
1520 get_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1521 GLuint count, GLint x, GLint y,
1522 GLvoid *values, GLenum type)
1523 {
1524 GLint skip = 0;
1525 GLubyte *src;
1526
1527 if (y < 0 || y >= (GLint) rb->Height)
1528 return; /* above or below */
1529
1530 if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
1531 return; /* entirely left or right */
1532
1533 if (x + count > rb->Width) {
1534 /* right clip */
1535 GLint clip = x + count - rb->Width;
1536 count -= clip;
1537 }
1538
1539 if (x < 0) {
1540 /* left clip */
1541 skip = -x;
1542 x = 0;
1543 count -= skip;
1544 }
1545
1546 src = _swrast_pixel_address(rb, x, y);
1547
1548 if (type == GL_UNSIGNED_BYTE) {
1549 _mesa_unpack_ubyte_rgba_row(rb->Format, count, src,
1550 (GLubyte (*)[4]) values + skip);
1551 }
1552 else if (type == GL_FLOAT) {
1553 _mesa_unpack_rgba_row(rb->Format, count, src,
1554 (GLfloat (*)[4]) values + skip);
1555 }
1556 else {
1557 _mesa_problem(ctx, "unexpected type in get_row()");
1558 }
1559 }
1560
1561
1562 /**
1563 * Get RGBA pixels from the given renderbuffer.
1564 * Used by blending, logicop and masking functions.
1565 * \return pointer to the colors we read.
1566 */
1567 void *
1568 _swrast_get_dest_rgba(struct gl_context *ctx, struct gl_renderbuffer *rb,
1569 SWspan *span)
1570 {
1571 void *rbPixels;
1572
1573 /* Point rbPixels to a temporary space */
1574 rbPixels = span->array->attribs[FRAG_ATTRIB_MAX - 1];
1575
1576 /* Get destination values from renderbuffer */
1577 if (span->arrayMask & SPAN_XY) {
1578 get_values(ctx, rb, span->end, span->array->x, span->array->y,
1579 rbPixels, span->array->ChanType);
1580 }
1581 else {
1582 get_row(ctx, rb, span->end, span->x, span->y,
1583 rbPixels, span->array->ChanType);
1584 }
1585
1586 return rbPixels;
1587 }