projects / mesa.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
Merge branch 'glsl2'
[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/macros.h"
37 #include "main/imports.h"
38 #include "main/image.h"
39
40 #include "s_atifragshader.h"
41 #include "s_alpha.h"
42 #include "s_blend.h"
43 #include "s_context.h"
44 #include "s_depth.h"
45 #include "s_fog.h"
46 #include "s_logic.h"
47 #include "s_masking.h"
48 #include "s_fragprog.h"
49 #include "s_span.h"
50 #include "s_stencil.h"
51 #include "s_texcombine.h"
52
53
54 /**
55 * Set default fragment attributes for the span using the
56 * current raster values. Used prior to glDraw/CopyPixels
57 * and glBitmap.
58 */
59 void
60 _swrast_span_default_attribs(GLcontext *ctx, SWspan *span)
61 {
62 GLchan r, g, b, a;
63 /* Z*/
64 {
65 const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;
66 if (ctx->DrawBuffer->Visual.depthBits <= 16)
67 span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);
68 else {
69 GLfloat tmpf = ctx->Current.RasterPos[2] * depthMax;
70 tmpf = MIN2(tmpf, depthMax);
71 span->z = (GLint)tmpf;
72 }
73 span->zStep = 0;
74 span->interpMask |= SPAN_Z;
75 }
76
77 /* W (for perspective correction) */
78 span->attrStart[FRAG_ATTRIB_WPOS][3] = 1.0;
79 span->attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0;
80 span->attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0;
81
82 /* primary color, or color index */
83 UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);
84 UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);
85 UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);
86 UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);
87 #if CHAN_TYPE == GL_FLOAT
88 span->red = r;
89 span->green = g;
90 span->blue = b;
91 span->alpha = a;
92 #else
93 span->red = IntToFixed(r);
94 span->green = IntToFixed(g);
95 span->blue = IntToFixed(b);
96 span->alpha = IntToFixed(a);
97 #endif
98 span->redStep = 0;
99 span->greenStep = 0;
100 span->blueStep = 0;
101 span->alphaStep = 0;
102 span->interpMask |= SPAN_RGBA;
103
104 COPY_4V(span->attrStart[FRAG_ATTRIB_COL0], ctx->Current.RasterColor);
105 ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
106 ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
107
108 /* Secondary color */
109 if (ctx->Light.Enabled || ctx->Fog.ColorSumEnabled)
110 {
111 COPY_4V(span->attrStart[FRAG_ATTRIB_COL1], ctx->Current.RasterSecondaryColor);
112 ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
113 ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
114 }
115
116 /* fog */
117 {
118 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
119 GLfloat fogVal; /* a coord or a blend factor */
120 if (swrast->_PreferPixelFog) {
121 /* fog blend factors will be computed from fog coordinates per pixel */
122 fogVal = ctx->Current.RasterDistance;
123 }
124 else {
125 /* fog blend factor should be computed from fogcoord now */
126 fogVal = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);
127 }
128 span->attrStart[FRAG_ATTRIB_FOGC][0] = fogVal;
129 span->attrStepX[FRAG_ATTRIB_FOGC][0] = 0.0;
130 span->attrStepY[FRAG_ATTRIB_FOGC][0] = 0.0;
131 }
132
133 /* texcoords */
134 {
135 GLuint i;
136 for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
137 const GLuint attr = FRAG_ATTRIB_TEX0 + i;
138 const GLfloat *tc = ctx->Current.RasterTexCoords[i];
139 if (ctx->FragmentProgram._Current || ctx->ATIFragmentShader._Enabled) {
140 COPY_4V(span->attrStart[attr], tc);
141 }
142 else if (tc[3] > 0.0F) {
143 /* use (s/q, t/q, r/q, 1) */
144 span->attrStart[attr][0] = tc[0] / tc[3];
145 span->attrStart[attr][1] = tc[1] / tc[3];
146 span->attrStart[attr][2] = tc[2] / tc[3];
147 span->attrStart[attr][3] = 1.0;
148 }
149 else {
150 ASSIGN_4V(span->attrStart[attr], 0.0F, 0.0F, 0.0F, 1.0F);
151 }
152 ASSIGN_4V(span->attrStepX[attr], 0.0F, 0.0F, 0.0F, 0.0F);
153 ASSIGN_4V(span->attrStepY[attr], 0.0F, 0.0F, 0.0F, 0.0F);
154 }
155 }
156 }
157
158
159 /**
160 * Interpolate the active attributes (and'd with attrMask) to
161 * fill in span->array->attribs[].
162 * Perspective correction will be done. The point/line/triangle function
163 * should have computed attrStart/Step values for FRAG_ATTRIB_WPOS[3]!
164 */
165 static INLINE void
166 interpolate_active_attribs(GLcontext *ctx, SWspan *span, GLbitfield attrMask)
167 {
168 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
169
170 /*
171 * Don't overwrite existing array values, such as colors that may have
172 * been produced by glDraw/CopyPixels.
173 */
174 attrMask &= ~span->arrayAttribs;
175
176 ATTRIB_LOOP_BEGIN
177 if (attrMask & (1 << attr)) {
178 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
179 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3];
180 const GLfloat dv0dx = span->attrStepX[attr][0];
181 const GLfloat dv1dx = span->attrStepX[attr][1];
182 const GLfloat dv2dx = span->attrStepX[attr][2];
183 const GLfloat dv3dx = span->attrStepX[attr][3];
184 GLfloat v0 = span->attrStart[attr][0] + span->leftClip * dv0dx;
185 GLfloat v1 = span->attrStart[attr][1] + span->leftClip * dv1dx;
186 GLfloat v2 = span->attrStart[attr][2] + span->leftClip * dv2dx;
187 GLfloat v3 = span->attrStart[attr][3] + span->leftClip * dv3dx;
188 GLuint k;
189 for (k = 0; k < span->end; k++) {
190 const GLfloat invW = 1.0f / w;
191 span->array->attribs[attr][k][0] = v0 * invW;
192 span->array->attribs[attr][k][1] = v1 * invW;
193 span->array->attribs[attr][k][2] = v2 * invW;
194 span->array->attribs[attr][k][3] = v3 * invW;
195 v0 += dv0dx;
196 v1 += dv1dx;
197 v2 += dv2dx;
198 v3 += dv3dx;
199 w += dwdx;
200 }
201 ASSERT((span->arrayAttribs & (1 << attr)) == 0);
202 span->arrayAttribs |= (1 << attr);
203 }
204 ATTRIB_LOOP_END
205 }
206
207
208 /**
209 * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
210 * color array.
211 */
212 static INLINE void
213 interpolate_int_colors(GLcontext *ctx, SWspan *span)
214 {
215 const GLuint n = span->end;
216 GLuint i;
217
218 #if CHAN_BITS != 32
219 ASSERT(!(span->arrayMask & SPAN_RGBA));
220 #endif
221
222 switch (span->array->ChanType) {
223 #if CHAN_BITS != 32
224 case GL_UNSIGNED_BYTE:
225 {
226 GLubyte (*rgba)[4] = span->array->rgba8;
227 if (span->interpMask & SPAN_FLAT) {
228 GLubyte color[4];
229 color[RCOMP] = FixedToInt(span->red);
230 color[GCOMP] = FixedToInt(span->green);
231 color[BCOMP] = FixedToInt(span->blue);
232 color[ACOMP] = FixedToInt(span->alpha);
233 for (i = 0; i < n; i++) {
234 COPY_4UBV(rgba[i], color);
235 }
236 }
237 else {
238 GLfixed r = span->red;
239 GLfixed g = span->green;
240 GLfixed b = span->blue;
241 GLfixed a = span->alpha;
242 GLint dr = span->redStep;
243 GLint dg = span->greenStep;
244 GLint db = span->blueStep;
245 GLint da = span->alphaStep;
246 for (i = 0; i < n; i++) {
247 rgba[i][RCOMP] = FixedToChan(r);
248 rgba[i][GCOMP] = FixedToChan(g);
249 rgba[i][BCOMP] = FixedToChan(b);
250 rgba[i][ACOMP] = FixedToChan(a);
251 r += dr;
252 g += dg;
253 b += db;
254 a += da;
255 }
256 }
257 }
258 break;
259 case GL_UNSIGNED_SHORT:
260 {
261 GLushort (*rgba)[4] = span->array->rgba16;
262 if (span->interpMask & SPAN_FLAT) {
263 GLushort color[4];
264 color[RCOMP] = FixedToInt(span->red);
265 color[GCOMP] = FixedToInt(span->green);
266 color[BCOMP] = FixedToInt(span->blue);
267 color[ACOMP] = FixedToInt(span->alpha);
268 for (i = 0; i < n; i++) {
269 COPY_4V(rgba[i], color);
270 }
271 }
272 else {
273 GLushort (*rgba)[4] = span->array->rgba16;
274 GLfixed r, g, b, a;
275 GLint dr, dg, db, da;
276 r = span->red;
277 g = span->green;
278 b = span->blue;
279 a = span->alpha;
280 dr = span->redStep;
281 dg = span->greenStep;
282 db = span->blueStep;
283 da = span->alphaStep;
284 for (i = 0; i < n; i++) {
285 rgba[i][RCOMP] = FixedToChan(r);
286 rgba[i][GCOMP] = FixedToChan(g);
287 rgba[i][BCOMP] = FixedToChan(b);
288 rgba[i][ACOMP] = FixedToChan(a);
289 r += dr;
290 g += dg;
291 b += db;
292 a += da;
293 }
294 }
295 }
296 break;
297 #endif
298 case GL_FLOAT:
299 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
300 break;
301 default:
302 _mesa_problem(NULL, "bad datatype in interpolate_int_colors");
303 }
304 span->arrayMask |= SPAN_RGBA;
305 }
306
307
308 /**
309 * Populate the FRAG_ATTRIB_COL0 array.
310 */
311 static INLINE void
312 interpolate_float_colors(SWspan *span)
313 {
314 GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
315 const GLuint n = span->end;
316 GLuint i;
317
318 assert(!(span->arrayAttribs & FRAG_BIT_COL0));
319
320 if (span->arrayMask & SPAN_RGBA) {
321 /* convert array of int colors */
322 for (i = 0; i < n; i++) {
323 col0[i][0] = UBYTE_TO_FLOAT(span->array->rgba8[i][0]);
324 col0[i][1] = UBYTE_TO_FLOAT(span->array->rgba8[i][1]);
325 col0[i][2] = UBYTE_TO_FLOAT(span->array->rgba8[i][2]);
326 col0[i][3] = UBYTE_TO_FLOAT(span->array->rgba8[i][3]);
327 }
328 }
329 else {
330 /* interpolate red/green/blue/alpha to get float colors */
331 ASSERT(span->interpMask & SPAN_RGBA);
332 if (span->interpMask & SPAN_FLAT) {
333 GLfloat r = FixedToFloat(span->red);
334 GLfloat g = FixedToFloat(span->green);
335 GLfloat b = FixedToFloat(span->blue);
336 GLfloat a = FixedToFloat(span->alpha);
337 for (i = 0; i < n; i++) {
338 ASSIGN_4V(col0[i], r, g, b, a);
339 }
340 }
341 else {
342 GLfloat r = FixedToFloat(span->red);
343 GLfloat g = FixedToFloat(span->green);
344 GLfloat b = FixedToFloat(span->blue);
345 GLfloat a = FixedToFloat(span->alpha);
346 GLfloat dr = FixedToFloat(span->redStep);
347 GLfloat dg = FixedToFloat(span->greenStep);
348 GLfloat db = FixedToFloat(span->blueStep);
349 GLfloat da = FixedToFloat(span->alphaStep);
350 for (i = 0; i < n; i++) {
351 col0[i][0] = r;
352 col0[i][1] = g;
353 col0[i][2] = b;
354 col0[i][3] = a;
355 r += dr;
356 g += dg;
357 b += db;
358 a += da;
359 }
360 }
361 }
362
363 span->arrayAttribs |= FRAG_BIT_COL0;
364 span->array->ChanType = GL_FLOAT;
365 }
366
367
368
369 /**
370 * Fill in the span.zArray array from the span->z, zStep values.
371 */
372 void
373 _swrast_span_interpolate_z( const GLcontext *ctx, SWspan *span )
374 {
375 const GLuint n = span->end;
376 GLuint i;
377
378 ASSERT(!(span->arrayMask & SPAN_Z));
379
380 if (ctx->DrawBuffer->Visual.depthBits <= 16) {
381 GLfixed zval = span->z;
382 GLuint *z = span->array->z;
383 for (i = 0; i < n; i++) {
384 z[i] = FixedToInt(zval);
385 zval += span->zStep;
386 }
387 }
388 else {
389 /* Deep Z buffer, no fixed->int shift */
390 GLuint zval = span->z;
391 GLuint *z = span->array->z;
392 for (i = 0; i < n; i++) {
393 z[i] = zval;
394 zval += span->zStep;
395 }
396 }
397 span->interpMask &= ~SPAN_Z;
398 span->arrayMask |= SPAN_Z;
399 }
400
401
402 /**
403 * Compute mipmap LOD from partial derivatives.
404 * This the ideal solution, as given in the OpenGL spec.
405 */
406 GLfloat
407 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
408 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
409 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
410 {
411 GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);
412 GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);
413 GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);
414 GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);
415 GLfloat x = SQRTF(dudx * dudx + dvdx * dvdx);
416 GLfloat y = SQRTF(dudy * dudy + dvdy * dvdy);
417 GLfloat rho = MAX2(x, y);
418 GLfloat lambda = LOG2(rho);
419 return lambda;
420 }
421
422
423 /**
424 * Compute mipmap LOD from partial derivatives.
425 * This is a faster approximation than above function.
426 */
427 #if 0
428 GLfloat
429 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
430 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
431 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
432 {
433 GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;
434 GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;
435 GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;
436 GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;
437 GLfloat maxU, maxV, rho, lambda;
438 dsdx2 = FABSF(dsdx2);
439 dsdy2 = FABSF(dsdy2);
440 dtdx2 = FABSF(dtdx2);
441 dtdy2 = FABSF(dtdy2);
442 maxU = MAX2(dsdx2, dsdy2) * texW;
443 maxV = MAX2(dtdx2, dtdy2) * texH;
444 rho = MAX2(maxU, maxV);
445 lambda = LOG2(rho);
446 return lambda;
447 }
448 #endif
449
450
451 /**
452 * Fill in the span.array->attrib[FRAG_ATTRIB_TEXn] arrays from the
453 * using the attrStart/Step values.
454 *
455 * This function only used during fixed-function fragment processing.
456 *
457 * Note: in the places where we divide by Q (or mult by invQ) we're
458 * really doing two things: perspective correction and texcoord
459 * projection. Remember, for texcoord (s,t,r,q) we need to index
460 * texels with (s/q, t/q, r/q).
461 */
462 static void
463 interpolate_texcoords(GLcontext *ctx, SWspan *span)
464 {
465 const GLuint maxUnit
466 = (ctx->Texture._EnabledCoordUnits > 1) ? ctx->Const.MaxTextureUnits : 1;
467 GLuint u;
468
469 /* XXX CoordUnits vs. ImageUnits */
470 for (u = 0; u < maxUnit; u++) {
471 if (ctx->Texture._EnabledCoordUnits & (1 << u)) {
472 const GLuint attr = FRAG_ATTRIB_TEX0 + u;
473 const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
474 GLfloat texW, texH;
475 GLboolean needLambda;
476 GLfloat (*texcoord)[4] = span->array->attribs[attr];
477 GLfloat *lambda = span->array->lambda[u];
478 const GLfloat dsdx = span->attrStepX[attr][0];
479 const GLfloat dsdy = span->attrStepY[attr][0];
480 const GLfloat dtdx = span->attrStepX[attr][1];
481 const GLfloat dtdy = span->attrStepY[attr][1];
482 const GLfloat drdx = span->attrStepX[attr][2];
483 const GLfloat dqdx = span->attrStepX[attr][3];
484 const GLfloat dqdy = span->attrStepY[attr][3];
485 GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx;
486 GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx;
487 GLfloat r = span->attrStart[attr][2] + span->leftClip * drdx;
488 GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx;
489
490 if (obj) {
491 const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel];
492 needLambda = (obj->MinFilter != obj->MagFilter)
493 || ctx->FragmentProgram._Current;
494 texW = img->WidthScale;
495 texH = img->HeightScale;
496 }
497 else {
498 /* using a fragment program */
499 texW = 1.0;
500 texH = 1.0;
501 needLambda = GL_FALSE;
502 }
503
504 if (needLambda) {
505 GLuint i;
506 if (ctx->FragmentProgram._Current
507 || ctx->ATIFragmentShader._Enabled) {
508 /* do perspective correction but don't divide s, t, r by q */
509 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
510 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
511 for (i = 0; i < span->end; i++) {
512 const GLfloat invW = 1.0F / w;
513 texcoord[i][0] = s * invW;
514 texcoord[i][1] = t * invW;
515 texcoord[i][2] = r * invW;
516 texcoord[i][3] = q * invW;
517 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
518 dqdx, dqdy, texW, texH,
519 s, t, q, invW);
520 s += dsdx;
521 t += dtdx;
522 r += drdx;
523 q += dqdx;
524 w += dwdx;
525 }
526 }
527 else {
528 for (i = 0; i < span->end; i++) {
529 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
530 texcoord[i][0] = s * invQ;
531 texcoord[i][1] = t * invQ;
532 texcoord[i][2] = r * invQ;
533 texcoord[i][3] = q;
534 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
535 dqdx, dqdy, texW, texH,
536 s, t, q, invQ);
537 s += dsdx;
538 t += dtdx;
539 r += drdx;
540 q += dqdx;
541 }
542 }
543 span->arrayMask |= SPAN_LAMBDA;
544 }
545 else {
546 GLuint i;
547 if (ctx->FragmentProgram._Current ||
548 ctx->ATIFragmentShader._Enabled) {
549 /* do perspective correction but don't divide s, t, r by q */
550 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
551 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
552 for (i = 0; i < span->end; i++) {
553 const GLfloat invW = 1.0F / w;
554 texcoord[i][0] = s * invW;
555 texcoord[i][1] = t * invW;
556 texcoord[i][2] = r * invW;
557 texcoord[i][3] = q * invW;
558 lambda[i] = 0.0;
559 s += dsdx;
560 t += dtdx;
561 r += drdx;
562 q += dqdx;
563 w += dwdx;
564 }
565 }
566 else if (dqdx == 0.0F) {
567 /* Ortho projection or polygon's parallel to window X axis */
568 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
569 for (i = 0; i < span->end; i++) {
570 texcoord[i][0] = s * invQ;
571 texcoord[i][1] = t * invQ;
572 texcoord[i][2] = r * invQ;
573 texcoord[i][3] = q;
574 lambda[i] = 0.0;
575 s += dsdx;
576 t += dtdx;
577 r += drdx;
578 }
579 }
580 else {
581 for (i = 0; i < span->end; i++) {
582 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
583 texcoord[i][0] = s * invQ;
584 texcoord[i][1] = t * invQ;
585 texcoord[i][2] = r * invQ;
586 texcoord[i][3] = q;
587 lambda[i] = 0.0;
588 s += dsdx;
589 t += dtdx;
590 r += drdx;
591 q += dqdx;
592 }
593 }
594 } /* lambda */
595 } /* if */
596 } /* for */
597 }
598
599
600 /**
601 * Fill in the arrays->attribs[FRAG_ATTRIB_WPOS] array.
602 */
603 static INLINE void
604 interpolate_wpos(GLcontext *ctx, SWspan *span)
605 {
606 GLfloat (*wpos)[4] = span->array->attribs[FRAG_ATTRIB_WPOS];
607 GLuint i;
608 const GLfloat zScale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
609 GLfloat w, dw;
610
611 if (span->arrayMask & SPAN_XY) {
612 for (i = 0; i < span->end; i++) {
613 wpos[i][0] = (GLfloat) span->array->x[i];
614 wpos[i][1] = (GLfloat) span->array->y[i];
615 }
616 }
617 else {
618 for (i = 0; i < span->end; i++) {
619 wpos[i][0] = (GLfloat) span->x + i;
620 wpos[i][1] = (GLfloat) span->y;
621 }
622 }
623
624 dw = span->attrStepX[FRAG_ATTRIB_WPOS][3];
625 w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dw;
626 for (i = 0; i < span->end; i++) {
627 wpos[i][2] = (GLfloat) span->array->z[i] * zScale;
628 wpos[i][3] = w;
629 w += dw;
630 }
631 }
632
633
634 /**
635 * Apply the current polygon stipple pattern to a span of pixels.
636 */
637 static INLINE void
638 stipple_polygon_span(GLcontext *ctx, SWspan *span)
639 {
640 GLubyte *mask = span->array->mask;
641
642 ASSERT(ctx->Polygon.StippleFlag);
643
644 if (span->arrayMask & SPAN_XY) {
645 /* arrays of x/y pixel coords */
646 GLuint i;
647 for (i = 0; i < span->end; i++) {
648 const GLint col = span->array->x[i] % 32;
649 const GLint row = span->array->y[i] % 32;
650 const GLuint stipple = ctx->PolygonStipple[row];
651 if (((1 << col) & stipple) == 0) {
652 mask[i] = 0;
653 }
654 }
655 }
656 else {
657 /* horizontal span of pixels */
658 const GLuint highBit = 1 << 31;
659 const GLuint stipple = ctx->PolygonStipple[span->y % 32];
660 GLuint i, m = highBit >> (GLuint) (span->x % 32);
661 for (i = 0; i < span->end; i++) {
662 if ((m & stipple) == 0) {
663 mask[i] = 0;
664 }
665 m = m >> 1;
666 if (m == 0) {
667 m = highBit;
668 }
669 }
670 }
671 span->writeAll = GL_FALSE;
672 }
673
674
675 /**
676 * Clip a pixel span to the current buffer/window boundaries:
677 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
678 * window clipping and scissoring.
679 * Return: GL_TRUE some pixels still visible
680 * GL_FALSE nothing visible
681 */
682 static INLINE GLuint
683 clip_span( GLcontext *ctx, SWspan *span )
684 {
685 const GLint xmin = ctx->DrawBuffer->_Xmin;
686 const GLint xmax = ctx->DrawBuffer->_Xmax;
687 const GLint ymin = ctx->DrawBuffer->_Ymin;
688 const GLint ymax = ctx->DrawBuffer->_Ymax;
689
690 span->leftClip = 0;
691
692 if (span->arrayMask & SPAN_XY) {
693 /* arrays of x/y pixel coords */
694 const GLint *x = span->array->x;
695 const GLint *y = span->array->y;
696 const GLint n = span->end;
697 GLubyte *mask = span->array->mask;
698 GLint i;
699 if (span->arrayMask & SPAN_MASK) {
700 /* note: using & intead of && to reduce branches */
701 for (i = 0; i < n; i++) {
702 mask[i] &= (x[i] >= xmin) & (x[i] < xmax)
703 & (y[i] >= ymin) & (y[i] < ymax);
704 }
705 }
706 else {
707 /* note: using & intead of && to reduce branches */
708 for (i = 0; i < n; i++) {
709 mask[i] = (x[i] >= xmin) & (x[i] < xmax)
710 & (y[i] >= ymin) & (y[i] < ymax);
711 }
712 }
713 return GL_TRUE; /* some pixels visible */
714 }
715 else {
716 /* horizontal span of pixels */
717 const GLint x = span->x;
718 const GLint y = span->y;
719 GLint n = span->end;
720
721 /* Trivial rejection tests */
722 if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {
723 span->end = 0;
724 return GL_FALSE; /* all pixels clipped */
725 }
726
727 /* Clip to right */
728 if (x + n > xmax) {
729 ASSERT(x < xmax);
730 n = span->end = xmax - x;
731 }
732
733 /* Clip to the left */
734 if (x < xmin) {
735 const GLint leftClip = xmin - x;
736 GLuint i;
737
738 ASSERT(leftClip > 0);
739 ASSERT(x + n > xmin);
740
741 /* Clip 'leftClip' pixels from the left side.
742 * The span->leftClip field will be applied when we interpolate
743 * fragment attributes.
744 * For arrays of values, shift them left.
745 */
746 for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
747 if (span->interpMask & (1 << i)) {
748 GLuint j;
749 for (j = 0; j < 4; j++) {
750 span->attrStart[i][j] += leftClip * span->attrStepX[i][j];
751 }
752 }
753 }
754
755 span->red += leftClip * span->redStep;
756 span->green += leftClip * span->greenStep;
757 span->blue += leftClip * span->blueStep;
758 span->alpha += leftClip * span->alphaStep;
759 span->index += leftClip * span->indexStep;
760 span->z += leftClip * span->zStep;
761 span->intTex[0] += leftClip * span->intTexStep[0];
762 span->intTex[1] += leftClip * span->intTexStep[1];
763
764 #define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
765 memcpy(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
766
767 for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
768 if (span->arrayAttribs & (1 << i)) {
769 /* shift array elements left by 'leftClip' */
770 SHIFT_ARRAY(span->array->attribs[i], leftClip, n - leftClip);
771 }
772 }
773
774 SHIFT_ARRAY(span->array->mask, leftClip, n - leftClip);
775 SHIFT_ARRAY(span->array->rgba8, leftClip, n - leftClip);
776 SHIFT_ARRAY(span->array->rgba16, leftClip, n - leftClip);
777 SHIFT_ARRAY(span->array->x, leftClip, n - leftClip);
778 SHIFT_ARRAY(span->array->y, leftClip, n - leftClip);
779 SHIFT_ARRAY(span->array->z, leftClip, n - leftClip);
780 SHIFT_ARRAY(span->array->index, leftClip, n - leftClip);
781 for (i = 0; i < MAX_TEXTURE_COORD_UNITS; i++) {
782 SHIFT_ARRAY(span->array->lambda[i], leftClip, n - leftClip);
783 }
784 SHIFT_ARRAY(span->array->coverage, leftClip, n - leftClip);
785
786 #undef SHIFT_ARRAY
787
788 span->leftClip = leftClip;
789 span->x = xmin;
790 span->end -= leftClip;
791 span->writeAll = GL_FALSE;
792 }
793
794 ASSERT(span->x >= xmin);
795 ASSERT(span->x + span->end <= xmax);
796 ASSERT(span->y >= ymin);
797 ASSERT(span->y < ymax);
798
799 return GL_TRUE; /* some pixels visible */
800 }
801 }
802
803
804 /**
805 * Add specular colors to primary colors.
806 * Only called during fixed-function operation.
807 * Result is float color array (FRAG_ATTRIB_COL0).
808 */
809 static INLINE void
810 add_specular(GLcontext *ctx, SWspan *span)
811 {
812 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
813 const GLubyte *mask = span->array->mask;
814 GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
815 GLfloat (*col1)[4] = span->array->attribs[FRAG_ATTRIB_COL1];
816 GLuint i;
817
818 ASSERT(!ctx->FragmentProgram._Current);
819 ASSERT(span->arrayMask & SPAN_RGBA);
820 ASSERT(swrast->_ActiveAttribMask & FRAG_BIT_COL1);
821 (void) swrast; /* silence warning */
822
823 if (span->array->ChanType == GL_FLOAT) {
824 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
825 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
826 }
827 }
828 else {
829 /* need float colors */
830 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
831 interpolate_float_colors(span);
832 }
833 }
834
835 if ((span->arrayAttribs & FRAG_BIT_COL1) == 0) {
836 /* XXX could avoid this and interpolate COL1 in the loop below */
837 interpolate_active_attribs(ctx, span, FRAG_BIT_COL1);
838 }
839
840 ASSERT(span->arrayAttribs & FRAG_BIT_COL0);
841 ASSERT(span->arrayAttribs & FRAG_BIT_COL1);
842
843 for (i = 0; i < span->end; i++) {
844 if (mask[i]) {
845 col0[i][0] += col1[i][0];
846 col0[i][1] += col1[i][1];
847 col0[i][2] += col1[i][2];
848 }
849 }
850
851 span->array->ChanType = GL_FLOAT;
852 }
853
854
855 /**
856 * Apply antialiasing coverage value to alpha values.
857 */
858 static INLINE void
859 apply_aa_coverage(SWspan *span)
860 {
861 const GLfloat *coverage = span->array->coverage;
862 GLuint i;
863 if (span->array->ChanType == GL_UNSIGNED_BYTE) {
864 GLubyte (*rgba)[4] = span->array->rgba8;
865 for (i = 0; i < span->end; i++) {
866 const GLfloat a = rgba[i][ACOMP] * coverage[i];
867 rgba[i][ACOMP] = (GLubyte) CLAMP(a, 0.0, 255.0);
868 ASSERT(coverage[i] >= 0.0);
869 ASSERT(coverage[i] <= 1.0);
870 }
871 }
872 else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
873 GLushort (*rgba)[4] = span->array->rgba16;
874 for (i = 0; i < span->end; i++) {
875 const GLfloat a = rgba[i][ACOMP] * coverage[i];
876 rgba[i][ACOMP] = (GLushort) CLAMP(a, 0.0, 65535.0);
877 }
878 }
879 else {
880 GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
881 for (i = 0; i < span->end; i++) {
882 rgba[i][ACOMP] = rgba[i][ACOMP] * coverage[i];
883 /* clamp later */
884 }
885 }
886 }
887
888
889 /**
890 * Clamp span's float colors to [0,1]
891 */
892 static INLINE void
893 clamp_colors(SWspan *span)
894 {
895 GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
896 GLuint i;
897 ASSERT(span->array->ChanType == GL_FLOAT);
898 for (i = 0; i < span->end; i++) {
899 rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
900 rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
901 rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
902 rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
903 }
904 }
905
906
907 /**
908 * Convert the span's color arrays to the given type.
909 * The only way 'output' can be greater than zero is when we have a fragment
910 * program that writes to gl_FragData[1] or higher.
911 * \param output which fragment program color output is being processed
912 */
913 static INLINE void
914 convert_color_type(SWspan *span, GLenum newType, GLuint output)
915 {
916 GLvoid *src, *dst;
917
918 if (output > 0 || span->array->ChanType == GL_FLOAT) {
919 src = span->array->attribs[FRAG_ATTRIB_COL0 + output];
920 span->array->ChanType = GL_FLOAT;
921 }
922 else if (span->array->ChanType == GL_UNSIGNED_BYTE) {
923 src = span->array->rgba8;
924 }
925 else {
926 ASSERT(span->array->ChanType == GL_UNSIGNED_SHORT);
927 src = span->array->rgba16;
928 }
929
930 if (newType == GL_UNSIGNED_BYTE) {
931 dst = span->array->rgba8;
932 }
933 else if (newType == GL_UNSIGNED_SHORT) {
934 dst = span->array->rgba16;
935 }
936 else {
937 dst = span->array->attribs[FRAG_ATTRIB_COL0];
938 }
939
940 _mesa_convert_colors(span->array->ChanType, src,
941 newType, dst,
942 span->end, span->array->mask);
943
944 span->array->ChanType = newType;
945 span->array->rgba = dst;
946 }
947
948
949
950 /**
951 * Apply fragment shader, fragment program or normal texturing to span.
952 */
953 static INLINE void
954 shade_texture_span(GLcontext *ctx, SWspan *span)
955 {
956 GLbitfield inputsRead;
957
958 /* Determine which fragment attributes are actually needed */
959 if (ctx->FragmentProgram._Current) {
960 inputsRead = ctx->FragmentProgram._Current->Base.InputsRead;
961 }
962 else {
963 /* XXX we could be a bit smarter about this */
964 inputsRead = ~0;
965 }
966
967 if (ctx->FragmentProgram._Current ||
968 ctx->ATIFragmentShader._Enabled) {
969 /* programmable shading */
970 if (span->primitive == GL_BITMAP && span->array->ChanType != GL_FLOAT) {
971 convert_color_type(span, GL_FLOAT, 0);
972 }
973 else {
974 span->array->rgba = (void *) span->array->attribs[FRAG_ATTRIB_COL0];
975 }
976
977 if (span->primitive != GL_POINT ||
978 (span->interpMask & SPAN_RGBA) ||
979 ctx->Point.PointSprite) {
980 /* for single-pixel points, we populated the arrays already */
981 interpolate_active_attribs(ctx, span, ~0);
982 }
983 span->array->ChanType = GL_FLOAT;
984
985 if (!(span->arrayMask & SPAN_Z))
986 _swrast_span_interpolate_z (ctx, span);
987
988 #if 0
989 if (inputsRead & FRAG_BIT_WPOS)
990 #else
991 /* XXX always interpolate wpos so that DDX/DDY work */
992 #endif
993 interpolate_wpos(ctx, span);
994
995 /* Run fragment program/shader now */
996 if (ctx->FragmentProgram._Current) {
997 _swrast_exec_fragment_program(ctx, span);
998 }
999 else {
1000 ASSERT(ctx->ATIFragmentShader._Enabled);
1001 _swrast_exec_fragment_shader(ctx, span);
1002 }
1003 }
1004 else if (ctx->Texture._EnabledCoordUnits) {
1005 /* conventional texturing */
1006
1007 #if CHAN_BITS == 32
1008 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
1009 interpolate_int_colors(ctx, span);
1010 }
1011 #else
1012 if (!(span->arrayMask & SPAN_RGBA))
1013 interpolate_int_colors(ctx, span);
1014 #endif
1015 if ((span->arrayAttribs & FRAG_BITS_TEX_ANY) == 0x0)
1016 interpolate_texcoords(ctx, span);
1017
1018 _swrast_texture_span(ctx, span);
1019 }
1020 }
1021
1022
1023
1024 /**
1025 * Apply all the per-fragment operations to a span.
1026 * This now includes texturing (_swrast_write_texture_span() is history).
1027 * This function may modify any of the array values in the span.
1028 * span->interpMask and span->arrayMask may be changed but will be restored
1029 * to their original values before returning.
1030 */
1031 void
1032 _swrast_write_rgba_span( GLcontext *ctx, SWspan *span)
1033 {
1034 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
1035 const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;
1036 const GLbitfield origInterpMask = span->interpMask;
1037 const GLbitfield origArrayMask = span->arrayMask;
1038 const GLbitfield origArrayAttribs = span->arrayAttribs;
1039 const GLenum origChanType = span->array->ChanType;
1040 void * const origRgba = span->array->rgba;
1041 const GLboolean shader = (ctx->FragmentProgram._Current
1042 || ctx->ATIFragmentShader._Enabled);
1043 const GLboolean shaderOrTexture = shader || ctx->Texture._EnabledCoordUnits;
1044 struct gl_framebuffer *fb = ctx->DrawBuffer;
1045
1046 /*
1047 printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__,
1048 span->interpMask, span->arrayMask);
1049 */
1050
1051 ASSERT(span->primitive == GL_POINT ||
1052 span->primitive == GL_LINE ||
1053 span->primitive == GL_POLYGON ||
1054 span->primitive == GL_BITMAP);
1055
1056 /* Fragment write masks */
1057 if (span->arrayMask & SPAN_MASK) {
1058 /* mask was initialized by caller, probably glBitmap */
1059 span->writeAll = GL_FALSE;
1060 }
1061 else {
1062 memset(span->array->mask, 1, span->end);
1063 span->writeAll = GL_TRUE;
1064 }
1065
1066 /* Clip to window/scissor box */
1067 if (!clip_span(ctx, span)) {
1068 return;
1069 }
1070
1071 ASSERT(span->end <= MAX_WIDTH);
1072
1073 /* Depth bounds test */
1074 if (ctx->Depth.BoundsTest && fb->Visual.depthBits > 0) {
1075 if (!_swrast_depth_bounds_test(ctx, span)) {
1076 return;
1077 }
1078 }
1079
1080 #ifdef DEBUG
1081 /* Make sure all fragments are within window bounds */
1082 if (span->arrayMask & SPAN_XY) {
1083 /* array of pixel locations */
1084 GLuint i;
1085 for (i = 0; i < span->end; i++) {
1086 if (span->array->mask[i]) {
1087 assert(span->array->x[i] >= fb->_Xmin);
1088 assert(span->array->x[i] < fb->_Xmax);
1089 assert(span->array->y[i] >= fb->_Ymin);
1090 assert(span->array->y[i] < fb->_Ymax);
1091 }
1092 }
1093 }
1094 #endif
1095
1096 /* Polygon Stippling */
1097 if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
1098 stipple_polygon_span(ctx, span);
1099 }
1100
1101 /* This is the normal place to compute the fragment color/Z
1102 * from texturing or shading.
1103 */
1104 if (shaderOrTexture && !swrast->_DeferredTexture) {
1105 shade_texture_span(ctx, span);
1106 }
1107
1108 /* Do the alpha test */
1109 if (ctx->Color.AlphaEnabled) {
1110 if (!_swrast_alpha_test(ctx, span)) {
1111 /* all fragments failed test */
1112 goto end;
1113 }
1114 }
1115
1116 /* Stencil and Z testing */
1117 if (ctx->Stencil._Enabled || ctx->Depth.Test) {
1118 if (!(span->arrayMask & SPAN_Z))
1119 _swrast_span_interpolate_z(ctx, span);
1120
1121 if (ctx->Transform.DepthClamp)
1122 _swrast_depth_clamp_span(ctx, span);
1123
1124 if (ctx->Stencil._Enabled) {
1125 /* Combined Z/stencil tests */
1126 if (!_swrast_stencil_and_ztest_span(ctx, span)) {
1127 /* all fragments failed test */
1128 goto end;
1129 }
1130 }
1131 else if (fb->Visual.depthBits > 0) {
1132 /* Just regular depth testing */
1133 ASSERT(ctx->Depth.Test);
1134 ASSERT(span->arrayMask & SPAN_Z);
1135 if (!_swrast_depth_test_span(ctx, span)) {
1136 /* all fragments failed test */
1137 goto end;
1138 }
1139 }
1140 }
1141
1142 if (ctx->Query.CurrentOcclusionObject) {
1143 /* update count of 'passed' fragments */
1144 struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
1145 GLuint i;
1146 for (i = 0; i < span->end; i++)
1147 q->Result += span->array->mask[i];
1148 }
1149
1150 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1151 * the occlusion test.
1152 */
1153 if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {
1154 /* no colors to write */
1155 goto end;
1156 }
1157
1158 /* If we were able to defer fragment color computation to now, there's
1159 * a good chance that many fragments will have already been killed by
1160 * Z/stencil testing.
1161 */
1162 if (shaderOrTexture && swrast->_DeferredTexture) {
1163 shade_texture_span(ctx, span);
1164 }
1165
1166 #if CHAN_BITS == 32
1167 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
1168 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
1169 }
1170 #else
1171 if ((span->arrayMask & SPAN_RGBA) == 0) {
1172 interpolate_int_colors(ctx, span);
1173 }
1174 #endif
1175
1176 ASSERT(span->arrayMask & SPAN_RGBA);
1177
1178 if (span->primitive == GL_BITMAP || !swrast->SpecularVertexAdd) {
1179 /* Add primary and specular (diffuse + specular) colors */
1180 if (!shader) {
1181 if (ctx->Fog.ColorSumEnabled ||
1182 (ctx->Light.Enabled &&
1183 ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {
1184 add_specular(ctx, span);
1185 }
1186 }
1187 }
1188
1189 /* Fog */
1190 if (swrast->_FogEnabled) {
1191 _swrast_fog_rgba_span(ctx, span);
1192 }
1193
1194 /* Antialias coverage application */
1195 if (span->arrayMask & SPAN_COVERAGE) {
1196 apply_aa_coverage(span);
1197 }
1198
1199 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1200 if (ctx->Color.ClampFragmentColor == GL_TRUE &&
1201 span->array->ChanType == GL_FLOAT) {
1202 clamp_colors(span);
1203 }
1204
1205 /*
1206 * Write to renderbuffers.
1207 * Depending on glDrawBuffer() state and the which color outputs are
1208 * written by the fragment shader, we may either replicate one color to
1209 * all renderbuffers or write a different color to each renderbuffer.
1210 * multiFragOutputs=TRUE for the later case.
1211 */
1212 {
1213 const GLuint numBuffers = fb->_NumColorDrawBuffers;
1214 const struct gl_fragment_program *fp = ctx->FragmentProgram._Current;
1215 const GLboolean multiFragOutputs =
1216 (fp && fp->Base.OutputsWritten >= (1 << FRAG_RESULT_DATA0));
1217 GLuint buf;
1218
1219 for (buf = 0; buf < numBuffers; buf++) {
1220 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];
1221
1222 /* color[fragOutput] will be written to buffer[buf] */
1223
1224 if (rb) {
1225 GLchan rgbaSave[MAX_WIDTH][4];
1226 const GLuint fragOutput = multiFragOutputs ? buf : 0;
1227
1228 /* set span->array->rgba to colors for render buffer's datatype */
1229 if (rb->DataType != span->array->ChanType || fragOutput > 0) {
1230 convert_color_type(span, rb->DataType, fragOutput);
1231 }
1232 else {
1233 if (rb->DataType == GL_UNSIGNED_BYTE) {
1234 span->array->rgba = span->array->rgba8;
1235 }
1236 else if (rb->DataType == GL_UNSIGNED_SHORT) {
1237 span->array->rgba = (void *) span->array->rgba16;
1238 }
1239 else {
1240 span->array->rgba = (void *)
1241 span->array->attribs[FRAG_ATTRIB_COL0];
1242 }
1243 }
1244
1245 if (!multiFragOutputs && numBuffers > 1) {
1246 /* save colors for second, third renderbuffer writes */
1247 memcpy(rgbaSave, span->array->rgba,
1248 4 * span->end * sizeof(GLchan));
1249 }
1250
1251 ASSERT(rb->_BaseFormat == GL_RGBA || rb->_BaseFormat == GL_RGB);
1252
1253 if (ctx->Color._LogicOpEnabled) {
1254 _swrast_logicop_rgba_span(ctx, rb, span);
1255 }
1256 else if ((ctx->Color.BlendEnabled >> buf) & 1) {
1257 _swrast_blend_span(ctx, rb, span);
1258 }
1259
1260 if (colorMask[buf] != 0xffffffff) {
1261 _swrast_mask_rgba_span(ctx, rb, span, buf);
1262 }
1263
1264 if (span->arrayMask & SPAN_XY) {
1265 /* array of pixel coords */
1266 ASSERT(rb->PutValues);
1267 rb->PutValues(ctx, rb, span->end,
1268 span->array->x, span->array->y,
1269 span->array->rgba, span->array->mask);
1270 }
1271 else {
1272 /* horizontal run of pixels */
1273 ASSERT(rb->PutRow);
1274 rb->PutRow(ctx, rb, span->end, span->x, span->y,
1275 span->array->rgba,
1276 span->writeAll ? NULL: span->array->mask);
1277 }
1278
1279 if (!multiFragOutputs && numBuffers > 1) {
1280 /* restore original span values */
1281 memcpy(span->array->rgba, rgbaSave,
1282 4 * span->end * sizeof(GLchan));
1283 }
1284
1285 } /* if rb */
1286 } /* for buf */
1287 }
1288
1289 end:
1290 /* restore these values before returning */
1291 span->interpMask = origInterpMask;
1292 span->arrayMask = origArrayMask;
1293 span->arrayAttribs = origArrayAttribs;
1294 span->array->ChanType = origChanType;
1295 span->array->rgba = origRgba;
1296 }
1297
1298
1299 /**
1300 * Read RGBA pixels from a renderbuffer. Clipping will be done to prevent
1301 * reading ouside the buffer's boundaries.
1302 * \param dstType datatype for returned colors
1303 * \param rgba the returned colors
1304 */
1305 void
1306 _swrast_read_rgba_span( GLcontext *ctx, struct gl_renderbuffer *rb,
1307 GLuint n, GLint x, GLint y, GLenum dstType,
1308 GLvoid *rgba)
1309 {
1310 const GLint bufWidth = (GLint) rb->Width;
1311 const GLint bufHeight = (GLint) rb->Height;
1312
1313 if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
1314 /* completely above, below, or right */
1315 /* XXX maybe leave rgba values undefined? */
1316 memset(rgba, 0, 4 * n * sizeof(GLchan));
1317 }
1318 else {
1319 GLint skip, length;
1320 if (x < 0) {
1321 /* left edge clipping */
1322 skip = -x;
1323 length = (GLint) n - skip;
1324 if (length < 0) {
1325 /* completely left of window */
1326 return;
1327 }
1328 if (length > bufWidth) {
1329 length = bufWidth;
1330 }
1331 }
1332 else if ((GLint) (x + n) > bufWidth) {
1333 /* right edge clipping */
1334 skip = 0;
1335 length = bufWidth - x;
1336 if (length < 0) {
1337 /* completely to right of window */
1338 return;
1339 }
1340 }
1341 else {
1342 /* no clipping */
1343 skip = 0;
1344 length = (GLint) n;
1345 }
1346
1347 ASSERT(rb);
1348 ASSERT(rb->GetRow);
1349 ASSERT(rb->_BaseFormat == GL_RGB || rb->_BaseFormat == GL_RGBA);
1350
1351 if (rb->DataType == dstType) {
1352 rb->GetRow(ctx, rb, length, x + skip, y,
1353 (GLubyte *) rgba + skip * RGBA_PIXEL_SIZE(rb->DataType));
1354 }
1355 else {
1356 GLuint temp[MAX_WIDTH * 4];
1357 rb->GetRow(ctx, rb, length, x + skip, y, temp);
1358 _mesa_convert_colors(rb->DataType, temp,
1359 dstType, (GLubyte *) rgba + skip * RGBA_PIXEL_SIZE(dstType),
1360 length, NULL);
1361 }
1362 }
1363 }
1364
1365
1366 /**
1367 * Wrapper for gl_renderbuffer::GetValues() which does clipping to avoid
1368 * reading values outside the buffer bounds.
1369 * We can use this for reading any format/type of renderbuffer.
1370 * \param valueSize is the size in bytes of each value (pixel) put into the
1371 * values array.
1372 */
1373 void
1374 _swrast_get_values(GLcontext *ctx, struct gl_renderbuffer *rb,
1375 GLuint count, const GLint x[], const GLint y[],
1376 void *values, GLuint valueSize)
1377 {
1378 GLuint i, inCount = 0, inStart = 0;
1379
1380 for (i = 0; i < count; i++) {
1381 if (x[i] >= 0 && y[i] >= 0 &&
1382 x[i] < (GLint) rb->Width && y[i] < (GLint) rb->Height) {
1383 /* inside */
1384 if (inCount == 0)
1385 inStart = i;
1386 inCount++;
1387 }
1388 else {
1389 if (inCount > 0) {
1390 /* read [inStart, inStart + inCount) */
1391 rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,
1392 (GLubyte *) values + inStart * valueSize);
1393 inCount = 0;
1394 }
1395 }
1396 }
1397 if (inCount > 0) {
1398 /* read last values */
1399 rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,
1400 (GLubyte *) values + inStart * valueSize);
1401 }
1402 }
1403
1404
1405 /**
1406 * Wrapper for gl_renderbuffer::PutRow() which does clipping.
1407 * \param valueSize size of each value (pixel) in bytes
1408 */
1409 void
1410 _swrast_put_row(GLcontext *ctx, struct gl_renderbuffer *rb,
1411 GLuint count, GLint x, GLint y,
1412 const GLvoid *values, GLuint valueSize)
1413 {
1414 GLint skip = 0;
1415
1416 if (y < 0 || y >= (GLint) rb->Height)
1417 return; /* above or below */
1418
1419 if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
1420 return; /* entirely left or right */
1421
1422 if ((GLint) (x + count) > (GLint) rb->Width) {
1423 /* right clip */
1424 GLint clip = x + count - rb->Width;
1425 count -= clip;
1426 }
1427
1428 if (x < 0) {
1429 /* left clip */
1430 skip = -x;
1431 x = 0;
1432 count -= skip;
1433 }
1434
1435 rb->PutRow(ctx, rb, count, x, y,
1436 (const GLubyte *) values + skip * valueSize, NULL);
1437 }
1438
1439
1440 /**
1441 * Wrapper for gl_renderbuffer::GetRow() which does clipping.
1442 * \param valueSize size of each value (pixel) in bytes
1443 */
1444 void
1445 _swrast_get_row(GLcontext *ctx, struct gl_renderbuffer *rb,
1446 GLuint count, GLint x, GLint y,
1447 GLvoid *values, GLuint valueSize)
1448 {
1449 GLint skip = 0;
1450
1451 if (y < 0 || y >= (GLint) rb->Height)
1452 return; /* above or below */
1453
1454 if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
1455 return; /* entirely left or right */
1456
1457 if (x + count > rb->Width) {
1458 /* right clip */
1459 GLint clip = x + count - rb->Width;
1460 count -= clip;
1461 }
1462
1463 if (x < 0) {
1464 /* left clip */
1465 skip = -x;
1466 x = 0;
1467 count -= skip;
1468 }
1469
1470 rb->GetRow(ctx, rb, count, x, y, (GLubyte *) values + skip * valueSize);
1471 }
1472
1473
1474 /**
1475 * Get RGBA pixels from the given renderbuffer.
1476 * Used by blending, logicop and masking functions.
1477 * \return pointer to the colors we read.
1478 */
1479 void *
1480 _swrast_get_dest_rgba(GLcontext *ctx, struct gl_renderbuffer *rb,
1481 SWspan *span)
1482 {
1483 const GLuint pixelSize = RGBA_PIXEL_SIZE(span->array->ChanType);
1484 void *rbPixels;
1485
1486 /* Point rbPixels to a temporary space */
1487 rbPixels = span->array->attribs[FRAG_ATTRIB_MAX - 1];
1488
1489 /* Get destination values from renderbuffer */
1490 if (span->arrayMask & SPAN_XY) {
1491 _swrast_get_values(ctx, rb, span->end, span->array->x, span->array->y,
1492 rbPixels, pixelSize);
1493 }
1494 else {
1495 _swrast_get_row(ctx, rb, span->end, span->x, span->y,
1496 rbPixels, pixelSize);
1497 }
1498
1499 return rbPixels;
1500 }