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 #include "main/samplerobj.h"
42
43 #include "s_atifragshader.h"
44 #include "s_alpha.h"
45 #include "s_blend.h"
46 #include "s_context.h"
47 #include "s_depth.h"
48 #include "s_fog.h"
49 #include "s_logic.h"
50 #include "s_masking.h"
51 #include "s_fragprog.h"
52 #include "s_span.h"
53 #include "s_stencil.h"
54 #include "s_texcombine.h"
55
56 #include <stdbool.h>
57
58 /**
59 * Set default fragment attributes for the span using the
60 * current raster values. Used prior to glDraw/CopyPixels
61 * and glBitmap.
62 */
63 void
_swrast_span_default_attribs(struct gl_context * ctx,SWspan * span)64 _swrast_span_default_attribs(struct gl_context *ctx, SWspan *span)
65 {
66 GLchan r, g, b, a;
67 /* Z*/
68 {
69 const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;
70 if (ctx->DrawBuffer->Visual.depthBits <= 16)
71 span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);
72 else {
73 GLfloat tmpf = ctx->Current.RasterPos[2] * depthMax;
74 tmpf = MIN2(tmpf, depthMax);
75 span->z = (GLint)tmpf;
76 }
77 span->zStep = 0;
78 span->interpMask |= SPAN_Z;
79 }
80
81 /* W (for perspective correction) */
82 span->attrStart[FRAG_ATTRIB_WPOS][3] = 1.0;
83 span->attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0;
84 span->attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0;
85
86 /* primary color, or color index */
87 UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);
88 UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);
89 UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);
90 UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);
91 #if CHAN_TYPE == GL_FLOAT
92 span->red = r;
93 span->green = g;
94 span->blue = b;
95 span->alpha = a;
96 #else
97 span->red = IntToFixed(r);
98 span->green = IntToFixed(g);
99 span->blue = IntToFixed(b);
100 span->alpha = IntToFixed(a);
101 #endif
102 span->redStep = 0;
103 span->greenStep = 0;
104 span->blueStep = 0;
105 span->alphaStep = 0;
106 span->interpMask |= SPAN_RGBA;
107
108 COPY_4V(span->attrStart[FRAG_ATTRIB_COL0], ctx->Current.RasterColor);
109 ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
110 ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
111
112 /* Secondary color */
113 if (ctx->Light.Enabled || ctx->Fog.ColorSumEnabled)
114 {
115 COPY_4V(span->attrStart[FRAG_ATTRIB_COL1], ctx->Current.RasterSecondaryColor);
116 ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
117 ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
118 }
119
120 /* fog */
121 {
122 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
123 GLfloat fogVal; /* a coord or a blend factor */
124 if (swrast->_PreferPixelFog) {
125 /* fog blend factors will be computed from fog coordinates per pixel */
126 fogVal = ctx->Current.RasterDistance;
127 }
128 else {
129 /* fog blend factor should be computed from fogcoord now */
130 fogVal = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);
131 }
132 span->attrStart[FRAG_ATTRIB_FOGC][0] = fogVal;
133 span->attrStepX[FRAG_ATTRIB_FOGC][0] = 0.0;
134 span->attrStepY[FRAG_ATTRIB_FOGC][0] = 0.0;
135 }
136
137 /* texcoords */
138 {
139 GLuint i;
140 for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
141 const GLuint attr = FRAG_ATTRIB_TEX0 + i;
142 const GLfloat *tc = ctx->Current.RasterTexCoords[i];
143 if (_swrast_use_fragment_program(ctx) ||
144 ctx->ATIFragmentShader._Enabled) {
145 COPY_4V(span->attrStart[attr], tc);
146 }
147 else if (tc[3] > 0.0F) {
148 /* use (s/q, t/q, r/q, 1) */
149 span->attrStart[attr][0] = tc[0] / tc[3];
150 span->attrStart[attr][1] = tc[1] / tc[3];
151 span->attrStart[attr][2] = tc[2] / tc[3];
152 span->attrStart[attr][3] = 1.0;
153 }
154 else {
155 ASSIGN_4V(span->attrStart[attr], 0.0F, 0.0F, 0.0F, 1.0F);
156 }
157 ASSIGN_4V(span->attrStepX[attr], 0.0F, 0.0F, 0.0F, 0.0F);
158 ASSIGN_4V(span->attrStepY[attr], 0.0F, 0.0F, 0.0F, 0.0F);
159 }
160 }
161 }
162
163
164 /**
165 * Interpolate the active attributes (and'd with attrMask) to
166 * fill in span->array->attribs[].
167 * Perspective correction will be done. The point/line/triangle function
168 * should have computed attrStart/Step values for FRAG_ATTRIB_WPOS[3]!
169 */
170 static inline void
interpolate_active_attribs(struct gl_context * ctx,SWspan * span,GLbitfield64 attrMask)171 interpolate_active_attribs(struct gl_context *ctx, SWspan *span,
172 GLbitfield64 attrMask)
173 {
174 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
175
176 /*
177 * Don't overwrite existing array values, such as colors that may have
178 * been produced by glDraw/CopyPixels.
179 */
180 attrMask &= ~span->arrayAttribs;
181
182 ATTRIB_LOOP_BEGIN
183 if (attrMask & BITFIELD64_BIT(attr)) {
184 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
185 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3];
186 const GLfloat dv0dx = span->attrStepX[attr][0];
187 const GLfloat dv1dx = span->attrStepX[attr][1];
188 const GLfloat dv2dx = span->attrStepX[attr][2];
189 const GLfloat dv3dx = span->attrStepX[attr][3];
190 GLfloat v0 = span->attrStart[attr][0] + span->leftClip * dv0dx;
191 GLfloat v1 = span->attrStart[attr][1] + span->leftClip * dv1dx;
192 GLfloat v2 = span->attrStart[attr][2] + span->leftClip * dv2dx;
193 GLfloat v3 = span->attrStart[attr][3] + span->leftClip * dv3dx;
194 GLuint k;
195 for (k = 0; k < span->end; k++) {
196 const GLfloat invW = 1.0f / w;
197 span->array->attribs[attr][k][0] = v0 * invW;
198 span->array->attribs[attr][k][1] = v1 * invW;
199 span->array->attribs[attr][k][2] = v2 * invW;
200 span->array->attribs[attr][k][3] = v3 * invW;
201 v0 += dv0dx;
202 v1 += dv1dx;
203 v2 += dv2dx;
204 v3 += dv3dx;
205 w += dwdx;
206 }
207 ASSERT((span->arrayAttribs & BITFIELD64_BIT(attr)) == 0);
208 span->arrayAttribs |= BITFIELD64_BIT(attr);
209 }
210 ATTRIB_LOOP_END
211 }
212
213
214 /**
215 * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
216 * color array.
217 */
218 static inline void
interpolate_int_colors(struct gl_context * ctx,SWspan * span)219 interpolate_int_colors(struct gl_context *ctx, SWspan *span)
220 {
221 #if CHAN_BITS != 32
222 const GLuint n = span->end;
223 GLuint i;
224
225 ASSERT(!(span->arrayMask & SPAN_RGBA));
226 #endif
227
228 switch (span->array->ChanType) {
229 #if CHAN_BITS != 32
230 case GL_UNSIGNED_BYTE:
231 {
232 GLubyte (*rgba)[4] = span->array->rgba8;
233 if (span->interpMask & SPAN_FLAT) {
234 GLubyte color[4];
235 color[RCOMP] = FixedToInt(span->red);
236 color[GCOMP] = FixedToInt(span->green);
237 color[BCOMP] = FixedToInt(span->blue);
238 color[ACOMP] = FixedToInt(span->alpha);
239 for (i = 0; i < n; i++) {
240 COPY_4UBV(rgba[i], color);
241 }
242 }
243 else {
244 GLfixed r = span->red;
245 GLfixed g = span->green;
246 GLfixed b = span->blue;
247 GLfixed a = span->alpha;
248 GLint dr = span->redStep;
249 GLint dg = span->greenStep;
250 GLint db = span->blueStep;
251 GLint da = span->alphaStep;
252 for (i = 0; i < n; i++) {
253 rgba[i][RCOMP] = FixedToChan(r);
254 rgba[i][GCOMP] = FixedToChan(g);
255 rgba[i][BCOMP] = FixedToChan(b);
256 rgba[i][ACOMP] = FixedToChan(a);
257 r += dr;
258 g += dg;
259 b += db;
260 a += da;
261 }
262 }
263 }
264 break;
265 case GL_UNSIGNED_SHORT:
266 {
267 GLushort (*rgba)[4] = span->array->rgba16;
268 if (span->interpMask & SPAN_FLAT) {
269 GLushort color[4];
270 color[RCOMP] = FixedToInt(span->red);
271 color[GCOMP] = FixedToInt(span->green);
272 color[BCOMP] = FixedToInt(span->blue);
273 color[ACOMP] = FixedToInt(span->alpha);
274 for (i = 0; i < n; i++) {
275 COPY_4V(rgba[i], color);
276 }
277 }
278 else {
279 GLushort (*rgba)[4] = span->array->rgba16;
280 GLfixed r, g, b, a;
281 GLint dr, dg, db, da;
282 r = span->red;
283 g = span->green;
284 b = span->blue;
285 a = span->alpha;
286 dr = span->redStep;
287 dg = span->greenStep;
288 db = span->blueStep;
289 da = span->alphaStep;
290 for (i = 0; i < n; i++) {
291 rgba[i][RCOMP] = FixedToChan(r);
292 rgba[i][GCOMP] = FixedToChan(g);
293 rgba[i][BCOMP] = FixedToChan(b);
294 rgba[i][ACOMP] = FixedToChan(a);
295 r += dr;
296 g += dg;
297 b += db;
298 a += da;
299 }
300 }
301 }
302 break;
303 #endif
304 case GL_FLOAT:
305 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
306 break;
307 default:
308 _mesa_problem(ctx, "bad datatype 0x%x in interpolate_int_colors",
309 span->array->ChanType);
310 }
311 span->arrayMask |= SPAN_RGBA;
312 }
313
314
315 /**
316 * Populate the FRAG_ATTRIB_COL0 array.
317 */
318 static inline void
interpolate_float_colors(SWspan * span)319 interpolate_float_colors(SWspan *span)
320 {
321 GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
322 const GLuint n = span->end;
323 GLuint i;
324
325 assert(!(span->arrayAttribs & FRAG_BIT_COL0));
326
327 if (span->arrayMask & SPAN_RGBA) {
328 /* convert array of int colors */
329 for (i = 0; i < n; i++) {
330 col0[i][0] = UBYTE_TO_FLOAT(span->array->rgba8[i][0]);
331 col0[i][1] = UBYTE_TO_FLOAT(span->array->rgba8[i][1]);
332 col0[i][2] = UBYTE_TO_FLOAT(span->array->rgba8[i][2]);
333 col0[i][3] = UBYTE_TO_FLOAT(span->array->rgba8[i][3]);
334 }
335 }
336 else {
337 /* interpolate red/green/blue/alpha to get float colors */
338 ASSERT(span->interpMask & SPAN_RGBA);
339 if (span->interpMask & SPAN_FLAT) {
340 GLfloat r = FixedToFloat(span->red);
341 GLfloat g = FixedToFloat(span->green);
342 GLfloat b = FixedToFloat(span->blue);
343 GLfloat a = FixedToFloat(span->alpha);
344 for (i = 0; i < n; i++) {
345 ASSIGN_4V(col0[i], r, g, b, a);
346 }
347 }
348 else {
349 GLfloat r = FixedToFloat(span->red);
350 GLfloat g = FixedToFloat(span->green);
351 GLfloat b = FixedToFloat(span->blue);
352 GLfloat a = FixedToFloat(span->alpha);
353 GLfloat dr = FixedToFloat(span->redStep);
354 GLfloat dg = FixedToFloat(span->greenStep);
355 GLfloat db = FixedToFloat(span->blueStep);
356 GLfloat da = FixedToFloat(span->alphaStep);
357 for (i = 0; i < n; i++) {
358 col0[i][0] = r;
359 col0[i][1] = g;
360 col0[i][2] = b;
361 col0[i][3] = a;
362 r += dr;
363 g += dg;
364 b += db;
365 a += da;
366 }
367 }
368 }
369
370 span->arrayAttribs |= FRAG_BIT_COL0;
371 span->array->ChanType = GL_FLOAT;
372 }
373
374
375
376 /**
377 * Fill in the span.zArray array from the span->z, zStep values.
378 */
379 void
_swrast_span_interpolate_z(const struct gl_context * ctx,SWspan * span)380 _swrast_span_interpolate_z( const struct gl_context *ctx, SWspan *span )
381 {
382 const GLuint n = span->end;
383 GLuint i;
384
385 ASSERT(!(span->arrayMask & SPAN_Z));
386
387 if (ctx->DrawBuffer->Visual.depthBits <= 16) {
388 GLfixed zval = span->z;
389 GLuint *z = span->array->z;
390 for (i = 0; i < n; i++) {
391 z[i] = FixedToInt(zval);
392 zval += span->zStep;
393 }
394 }
395 else {
396 /* Deep Z buffer, no fixed->int shift */
397 GLuint zval = span->z;
398 GLuint *z = span->array->z;
399 for (i = 0; i < n; i++) {
400 z[i] = zval;
401 zval += span->zStep;
402 }
403 }
404 span->interpMask &= ~SPAN_Z;
405 span->arrayMask |= SPAN_Z;
406 }
407
408
409 /**
410 * Compute mipmap LOD from partial derivatives.
411 * This the ideal solution, as given in the OpenGL spec.
412 */
413 GLfloat
_swrast_compute_lambda(GLfloat dsdx,GLfloat dsdy,GLfloat dtdx,GLfloat dtdy,GLfloat dqdx,GLfloat dqdy,GLfloat texW,GLfloat texH,GLfloat s,GLfloat t,GLfloat q,GLfloat invQ)414 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
415 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
416 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
417 {
418 GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);
419 GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);
420 GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);
421 GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);
422 GLfloat x = SQRTF(dudx * dudx + dvdx * dvdx);
423 GLfloat y = SQRTF(dudy * dudy + dvdy * dvdy);
424 GLfloat rho = MAX2(x, y);
425 GLfloat lambda = LOG2(rho);
426 return lambda;
427 }
428
429
430 /**
431 * Compute mipmap LOD from partial derivatives.
432 * This is a faster approximation than above function.
433 */
434 #if 0
435 GLfloat
436 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
437 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
438 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
439 {
440 GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;
441 GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;
442 GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;
443 GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;
444 GLfloat maxU, maxV, rho, lambda;
445 dsdx2 = FABSF(dsdx2);
446 dsdy2 = FABSF(dsdy2);
447 dtdx2 = FABSF(dtdx2);
448 dtdy2 = FABSF(dtdy2);
449 maxU = MAX2(dsdx2, dsdy2) * texW;
450 maxV = MAX2(dtdx2, dtdy2) * texH;
451 rho = MAX2(maxU, maxV);
452 lambda = LOG2(rho);
453 return lambda;
454 }
455 #endif
456
457
458 /**
459 * Fill in the span.array->attrib[FRAG_ATTRIB_TEXn] arrays from the
460 * using the attrStart/Step values.
461 *
462 * This function only used during fixed-function fragment processing.
463 *
464 * Note: in the places where we divide by Q (or mult by invQ) we're
465 * really doing two things: perspective correction and texcoord
466 * projection. Remember, for texcoord (s,t,r,q) we need to index
467 * texels with (s/q, t/q, r/q).
468 */
469 static void
interpolate_texcoords(struct gl_context * ctx,SWspan * span)470 interpolate_texcoords(struct gl_context *ctx, SWspan *span)
471 {
472 const GLuint maxUnit
473 = (ctx->Texture._EnabledCoordUnits > 1) ? ctx->Const.MaxTextureUnits : 1;
474 GLuint u;
475
476 /* XXX CoordUnits vs. ImageUnits */
477 for (u = 0; u < maxUnit; u++) {
478 if (ctx->Texture._EnabledCoordUnits & (1 << u)) {
479 const GLuint attr = FRAG_ATTRIB_TEX0 + u;
480 const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
481 GLfloat texW, texH;
482 GLboolean needLambda;
483 GLfloat (*texcoord)[4] = span->array->attribs[attr];
484 GLfloat *lambda = span->array->lambda[u];
485 const GLfloat dsdx = span->attrStepX[attr][0];
486 const GLfloat dsdy = span->attrStepY[attr][0];
487 const GLfloat dtdx = span->attrStepX[attr][1];
488 const GLfloat dtdy = span->attrStepY[attr][1];
489 const GLfloat drdx = span->attrStepX[attr][2];
490 const GLfloat dqdx = span->attrStepX[attr][3];
491 const GLfloat dqdy = span->attrStepY[attr][3];
492 GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx;
493 GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx;
494 GLfloat r = span->attrStart[attr][2] + span->leftClip * drdx;
495 GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx;
496
497 if (obj) {
498 const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel];
499 const struct swrast_texture_image *swImg =
500 swrast_texture_image_const(img);
501 const struct gl_sampler_object *samp = _mesa_get_samplerobj(ctx, u);
502
503 needLambda = (samp->MinFilter != samp->MagFilter)
504 || _swrast_use_fragment_program(ctx);
505 /* LOD is calculated directly in the ansiotropic filter, we can
506 * skip the normal lambda function as the result is ignored.
507 */
508 if (samp->MaxAnisotropy > 1.0 &&
509 samp->MinFilter == GL_LINEAR_MIPMAP_LINEAR) {
510 needLambda = GL_FALSE;
511 }
512 texW = swImg->WidthScale;
513 texH = swImg->HeightScale;
514 }
515 else {
516 /* using a fragment program */
517 texW = 1.0;
518 texH = 1.0;
519 needLambda = GL_FALSE;
520 }
521
522 if (needLambda) {
523 GLuint i;
524 if (_swrast_use_fragment_program(ctx)
525 || ctx->ATIFragmentShader._Enabled) {
526 /* do perspective correction but don't divide s, t, r by q */
527 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
528 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
529 for (i = 0; i < span->end; i++) {
530 const GLfloat invW = 1.0F / w;
531 texcoord[i][0] = s * invW;
532 texcoord[i][1] = t * invW;
533 texcoord[i][2] = r * invW;
534 texcoord[i][3] = q * invW;
535 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
536 dqdx, dqdy, texW, texH,
537 s, t, q, invW);
538 s += dsdx;
539 t += dtdx;
540 r += drdx;
541 q += dqdx;
542 w += dwdx;
543 }
544 }
545 else {
546 for (i = 0; i < span->end; i++) {
547 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
548 texcoord[i][0] = s * invQ;
549 texcoord[i][1] = t * invQ;
550 texcoord[i][2] = r * invQ;
551 texcoord[i][3] = q;
552 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
553 dqdx, dqdy, texW, texH,
554 s, t, q, invQ);
555 s += dsdx;
556 t += dtdx;
557 r += drdx;
558 q += dqdx;
559 }
560 }
561 span->arrayMask |= SPAN_LAMBDA;
562 }
563 else {
564 GLuint i;
565 if (_swrast_use_fragment_program(ctx) ||
566 ctx->ATIFragmentShader._Enabled) {
567 /* do perspective correction but don't divide s, t, r by q */
568 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
569 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
570 for (i = 0; i < span->end; i++) {
571 const GLfloat invW = 1.0F / w;
572 texcoord[i][0] = s * invW;
573 texcoord[i][1] = t * invW;
574 texcoord[i][2] = r * invW;
575 texcoord[i][3] = q * invW;
576 lambda[i] = 0.0;
577 s += dsdx;
578 t += dtdx;
579 r += drdx;
580 q += dqdx;
581 w += dwdx;
582 }
583 }
584 else if (dqdx == 0.0F) {
585 /* Ortho projection or polygon's parallel to window X axis */
586 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
587 for (i = 0; i < span->end; i++) {
588 texcoord[i][0] = s * invQ;
589 texcoord[i][1] = t * invQ;
590 texcoord[i][2] = r * invQ;
591 texcoord[i][3] = q;
592 lambda[i] = 0.0;
593 s += dsdx;
594 t += dtdx;
595 r += drdx;
596 }
597 }
598 else {
599 for (i = 0; i < span->end; i++) {
600 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
601 texcoord[i][0] = s * invQ;
602 texcoord[i][1] = t * invQ;
603 texcoord[i][2] = r * invQ;
604 texcoord[i][3] = q;
605 lambda[i] = 0.0;
606 s += dsdx;
607 t += dtdx;
608 r += drdx;
609 q += dqdx;
610 }
611 }
612 } /* lambda */
613 } /* if */
614 } /* for */
615 }
616
617
618 /**
619 * Fill in the arrays->attribs[FRAG_ATTRIB_WPOS] array.
620 */
621 static inline void
interpolate_wpos(struct gl_context * ctx,SWspan * span)622 interpolate_wpos(struct gl_context *ctx, SWspan *span)
623 {
624 GLfloat (*wpos)[4] = span->array->attribs[FRAG_ATTRIB_WPOS];
625 GLuint i;
626 const GLfloat zScale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
627 GLfloat w, dw;
628
629 if (span->arrayMask & SPAN_XY) {
630 for (i = 0; i < span->end; i++) {
631 wpos[i][0] = (GLfloat) span->array->x[i];
632 wpos[i][1] = (GLfloat) span->array->y[i];
633 }
634 }
635 else {
636 for (i = 0; i < span->end; i++) {
637 wpos[i][0] = (GLfloat) span->x + i;
638 wpos[i][1] = (GLfloat) span->y;
639 }
640 }
641
642 dw = span->attrStepX[FRAG_ATTRIB_WPOS][3];
643 w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dw;
644 for (i = 0; i < span->end; i++) {
645 wpos[i][2] = (GLfloat) span->array->z[i] * zScale;
646 wpos[i][3] = w;
647 w += dw;
648 }
649 }
650
651
652 /**
653 * Apply the current polygon stipple pattern to a span of pixels.
654 */
655 static inline void
stipple_polygon_span(struct gl_context * ctx,SWspan * span)656 stipple_polygon_span(struct gl_context *ctx, SWspan *span)
657 {
658 GLubyte *mask = span->array->mask;
659
660 ASSERT(ctx->Polygon.StippleFlag);
661
662 if (span->arrayMask & SPAN_XY) {
663 /* arrays of x/y pixel coords */
664 GLuint i;
665 for (i = 0; i < span->end; i++) {
666 const GLint col = span->array->x[i] % 32;
667 const GLint row = span->array->y[i] % 32;
668 const GLuint stipple = ctx->PolygonStipple[row];
669 if (((1 << col) & stipple) == 0) {
670 mask[i] = 0;
671 }
672 }
673 }
674 else {
675 /* horizontal span of pixels */
676 const GLuint highBit = 1 << 31;
677 const GLuint stipple = ctx->PolygonStipple[span->y % 32];
678 GLuint i, m = highBit >> (GLuint) (span->x % 32);
679 for (i = 0; i < span->end; i++) {
680 if ((m & stipple) == 0) {
681 mask[i] = 0;
682 }
683 m = m >> 1;
684 if (m == 0) {
685 m = highBit;
686 }
687 }
688 }
689 span->writeAll = GL_FALSE;
690 }
691
692
693 /**
694 * Clip a pixel span to the current buffer/window boundaries:
695 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
696 * window clipping and scissoring.
697 * Return: GL_TRUE some pixels still visible
698 * GL_FALSE nothing visible
699 */
700 static inline GLuint
clip_span(struct gl_context * ctx,SWspan * span)701 clip_span( struct gl_context *ctx, SWspan *span )
702 {
703 const GLint xmin = ctx->DrawBuffer->_Xmin;
704 const GLint xmax = ctx->DrawBuffer->_Xmax;
705 const GLint ymin = ctx->DrawBuffer->_Ymin;
706 const GLint ymax = ctx->DrawBuffer->_Ymax;
707
708 span->leftClip = 0;
709
710 if (span->arrayMask & SPAN_XY) {
711 /* arrays of x/y pixel coords */
712 const GLint *x = span->array->x;
713 const GLint *y = span->array->y;
714 const GLint n = span->end;
715 GLubyte *mask = span->array->mask;
716 GLint i;
717 GLuint passed = 0;
718 if (span->arrayMask & SPAN_MASK) {
719 /* note: using & intead of && to reduce branches */
720 for (i = 0; i < n; i++) {
721 mask[i] &= (x[i] >= xmin) & (x[i] < xmax)
722 & (y[i] >= ymin) & (y[i] < ymax);
723 passed += mask[i];
724 }
725 }
726 else {
727 /* note: using & intead of && to reduce branches */
728 for (i = 0; i < n; i++) {
729 mask[i] = (x[i] >= xmin) & (x[i] < xmax)
730 & (y[i] >= ymin) & (y[i] < ymax);
731 passed += mask[i];
732 }
733 }
734 return passed > 0;
735 }
736 else {
737 /* horizontal span of pixels */
738 const GLint x = span->x;
739 const GLint y = span->y;
740 GLint n = span->end;
741
742 /* Trivial rejection tests */
743 if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {
744 span->end = 0;
745 return GL_FALSE; /* all pixels clipped */
746 }
747
748 /* Clip to right */
749 if (x + n > xmax) {
750 ASSERT(x < xmax);
751 n = span->end = xmax - x;
752 }
753
754 /* Clip to the left */
755 if (x < xmin) {
756 const GLint leftClip = xmin - x;
757 GLuint i;
758
759 ASSERT(leftClip > 0);
760 ASSERT(x + n > xmin);
761
762 /* Clip 'leftClip' pixels from the left side.
763 * The span->leftClip field will be applied when we interpolate
764 * fragment attributes.
765 * For arrays of values, shift them left.
766 */
767 for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
768 if (span->interpMask & (1 << i)) {
769 GLuint j;
770 for (j = 0; j < 4; j++) {
771 span->attrStart[i][j] += leftClip * span->attrStepX[i][j];
772 }
773 }
774 }
775
776 span->red += leftClip * span->redStep;
777 span->green += leftClip * span->greenStep;
778 span->blue += leftClip * span->blueStep;
779 span->alpha += leftClip * span->alphaStep;
780 span->index += leftClip * span->indexStep;
781 span->z += leftClip * span->zStep;
782 span->intTex[0] += leftClip * span->intTexStep[0];
783 span->intTex[1] += leftClip * span->intTexStep[1];
784
785 #define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
786 memmove(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
787
788 for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
789 if (span->arrayAttribs & (1 << i)) {
790 /* shift array elements left by 'leftClip' */
791 SHIFT_ARRAY(span->array->attribs[i], leftClip, n - leftClip);
792 }
793 }
794
795 SHIFT_ARRAY(span->array->mask, leftClip, n - leftClip);
796 SHIFT_ARRAY(span->array->rgba8, leftClip, n - leftClip);
797 SHIFT_ARRAY(span->array->rgba16, leftClip, n - leftClip);
798 SHIFT_ARRAY(span->array->x, leftClip, n - leftClip);
799 SHIFT_ARRAY(span->array->y, leftClip, n - leftClip);
800 SHIFT_ARRAY(span->array->z, leftClip, n - leftClip);
801 SHIFT_ARRAY(span->array->index, leftClip, n - leftClip);
802 for (i = 0; i < MAX_TEXTURE_COORD_UNITS; i++) {
803 SHIFT_ARRAY(span->array->lambda[i], leftClip, n - leftClip);
804 }
805 SHIFT_ARRAY(span->array->coverage, leftClip, n - leftClip);
806
807 #undef SHIFT_ARRAY
808
809 span->leftClip = leftClip;
810 span->x = xmin;
811 span->end -= leftClip;
812 span->writeAll = GL_FALSE;
813 }
814
815 ASSERT(span->x >= xmin);
816 ASSERT(span->x + span->end <= xmax);
817 ASSERT(span->y >= ymin);
818 ASSERT(span->y < ymax);
819
820 return GL_TRUE; /* some pixels visible */
821 }
822 }
823
824
825 /**
826 * Add specular colors to primary colors.
827 * Only called during fixed-function operation.
828 * Result is float color array (FRAG_ATTRIB_COL0).
829 */
830 static inline void
add_specular(struct gl_context * ctx,SWspan * span)831 add_specular(struct gl_context *ctx, SWspan *span)
832 {
833 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
834 const GLubyte *mask = span->array->mask;
835 GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
836 GLfloat (*col1)[4] = span->array->attribs[FRAG_ATTRIB_COL1];
837 GLuint i;
838
839 ASSERT(!_swrast_use_fragment_program(ctx));
840 ASSERT(span->arrayMask & SPAN_RGBA);
841 ASSERT(swrast->_ActiveAttribMask & FRAG_BIT_COL1);
842 (void) swrast; /* silence warning */
843
844 if (span->array->ChanType == GL_FLOAT) {
845 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
846 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
847 }
848 }
849 else {
850 /* need float colors */
851 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
852 interpolate_float_colors(span);
853 }
854 }
855
856 if ((span->arrayAttribs & FRAG_BIT_COL1) == 0) {
857 /* XXX could avoid this and interpolate COL1 in the loop below */
858 interpolate_active_attribs(ctx, span, FRAG_BIT_COL1);
859 }
860
861 ASSERT(span->arrayAttribs & FRAG_BIT_COL0);
862 ASSERT(span->arrayAttribs & FRAG_BIT_COL1);
863
864 for (i = 0; i < span->end; i++) {
865 if (mask[i]) {
866 col0[i][0] += col1[i][0];
867 col0[i][1] += col1[i][1];
868 col0[i][2] += col1[i][2];
869 }
870 }
871
872 span->array->ChanType = GL_FLOAT;
873 }
874
875
876 /**
877 * Apply antialiasing coverage value to alpha values.
878 */
879 static inline void
apply_aa_coverage(SWspan * span)880 apply_aa_coverage(SWspan *span)
881 {
882 const GLfloat *coverage = span->array->coverage;
883 GLuint i;
884 if (span->array->ChanType == GL_UNSIGNED_BYTE) {
885 GLubyte (*rgba)[4] = span->array->rgba8;
886 for (i = 0; i < span->end; i++) {
887 const GLfloat a = rgba[i][ACOMP] * coverage[i];
888 rgba[i][ACOMP] = (GLubyte) CLAMP(a, 0.0, 255.0);
889 ASSERT(coverage[i] >= 0.0);
890 ASSERT(coverage[i] <= 1.0);
891 }
892 }
893 else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
894 GLushort (*rgba)[4] = span->array->rgba16;
895 for (i = 0; i < span->end; i++) {
896 const GLfloat a = rgba[i][ACOMP] * coverage[i];
897 rgba[i][ACOMP] = (GLushort) CLAMP(a, 0.0, 65535.0);
898 }
899 }
900 else {
901 GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
902 for (i = 0; i < span->end; i++) {
903 rgba[i][ACOMP] = rgba[i][ACOMP] * coverage[i];
904 /* clamp later */
905 }
906 }
907 }
908
909
910 /**
911 * Clamp span's float colors to [0,1]
912 */
913 static inline void
clamp_colors(SWspan * span)914 clamp_colors(SWspan *span)
915 {
916 GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
917 GLuint i;
918 ASSERT(span->array->ChanType == GL_FLOAT);
919 for (i = 0; i < span->end; i++) {
920 rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
921 rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
922 rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
923 rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
924 }
925 }
926
927
928 /**
929 * Convert the span's color arrays to the given type.
930 * The only way 'output' can be greater than zero is when we have a fragment
931 * program that writes to gl_FragData[1] or higher.
932 * \param output which fragment program color output is being processed
933 */
934 static inline void
convert_color_type(SWspan * span,GLenum newType,GLuint output)935 convert_color_type(SWspan *span, GLenum newType, GLuint output)
936 {
937 GLvoid *src, *dst;
938
939 if (output > 0 || span->array->ChanType == GL_FLOAT) {
940 src = span->array->attribs[FRAG_ATTRIB_COL0 + output];
941 span->array->ChanType = GL_FLOAT;
942 }
943 else if (span->array->ChanType == GL_UNSIGNED_BYTE) {
944 src = span->array->rgba8;
945 }
946 else {
947 ASSERT(span->array->ChanType == GL_UNSIGNED_SHORT);
948 src = span->array->rgba16;
949 }
950
951 if (newType == GL_UNSIGNED_BYTE) {
952 dst = span->array->rgba8;
953 }
954 else if (newType == GL_UNSIGNED_SHORT) {
955 dst = span->array->rgba16;
956 }
957 else {
958 dst = span->array->attribs[FRAG_ATTRIB_COL0];
959 }
960
961 _mesa_convert_colors(span->array->ChanType, src,
962 newType, dst,
963 span->end, span->array->mask);
964
965 span->array->ChanType = newType;
966 span->array->rgba = dst;
967 }
968
969
970
971 /**
972 * Apply fragment shader, fragment program or normal texturing to span.
973 */
974 static inline void
shade_texture_span(struct gl_context * ctx,SWspan * span)975 shade_texture_span(struct gl_context *ctx, SWspan *span)
976 {
977 if (_swrast_use_fragment_program(ctx) ||
978 ctx->ATIFragmentShader._Enabled) {
979 /* programmable shading */
980 if (span->primitive == GL_BITMAP && span->array->ChanType != GL_FLOAT) {
981 convert_color_type(span, GL_FLOAT, 0);
982 }
983 else {
984 span->array->rgba = (void *) span->array->attribs[FRAG_ATTRIB_COL0];
985 }
986
987 if (span->primitive != GL_POINT ||
988 (span->interpMask & SPAN_RGBA) ||
989 ctx->Point.PointSprite) {
990 /* for single-pixel points, we populated the arrays already */
991 interpolate_active_attribs(ctx, span, ~0);
992 }
993 span->array->ChanType = GL_FLOAT;
994
995 if (!(span->arrayMask & SPAN_Z))
996 _swrast_span_interpolate_z (ctx, span);
997
998 #if 0
999 if (inputsRead & FRAG_BIT_WPOS)
1000 #else
1001 /* XXX always interpolate wpos so that DDX/DDY work */
1002 #endif
1003 interpolate_wpos(ctx, span);
1004
1005 /* Run fragment program/shader now */
1006 if (_swrast_use_fragment_program(ctx)) {
1007 _swrast_exec_fragment_program(ctx, span);
1008 }
1009 else {
1010 ASSERT(ctx->ATIFragmentShader._Enabled);
1011 _swrast_exec_fragment_shader(ctx, span);
1012 }
1013 }
1014 else if (ctx->Texture._EnabledCoordUnits) {
1015 /* conventional texturing */
1016
1017 #if CHAN_BITS == 32
1018 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
1019 interpolate_int_colors(ctx, span);
1020 }
1021 #else
1022 if (!(span->arrayMask & SPAN_RGBA))
1023 interpolate_int_colors(ctx, span);
1024 #endif
1025 if ((span->arrayAttribs & FRAG_BITS_TEX_ANY) == 0x0)
1026 interpolate_texcoords(ctx, span);
1027
1028 _swrast_texture_span(ctx, span);
1029 }
1030 }
1031
1032
1033 /** Put colors at x/y locations into a renderbuffer */
1034 static void
put_values(struct gl_context * ctx,struct gl_renderbuffer * rb,GLenum datatype,GLuint count,const GLint x[],const GLint y[],const void * values,const GLubyte * mask)1035 put_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1036 GLenum datatype,
1037 GLuint count, const GLint x[], const GLint y[],
1038 const void *values, const GLubyte *mask)
1039 {
1040 gl_pack_ubyte_rgba_func pack_ubyte = NULL;
1041 gl_pack_float_rgba_func pack_float = NULL;
1042 GLuint i;
1043
1044 if (datatype == GL_UNSIGNED_BYTE)
1045 pack_ubyte = _mesa_get_pack_ubyte_rgba_function(rb->Format);
1046 else
1047 pack_float = _mesa_get_pack_float_rgba_function(rb->Format);
1048
1049 for (i = 0; i < count; i++) {
1050 if (mask[i]) {
1051 GLubyte *dst = _swrast_pixel_address(rb, x[i], y[i]);
1052
1053 if (datatype == GL_UNSIGNED_BYTE) {
1054 pack_ubyte((const GLubyte *) values + 4 * i, dst);
1055 }
1056 else {
1057 assert(datatype == GL_FLOAT);
1058 pack_float((const GLfloat *) values + 4 * i, dst);
1059 }
1060 }
1061 }
1062 }
1063
1064
1065 /** Put row of colors into renderbuffer */
1066 void
_swrast_put_row(struct gl_context * ctx,struct gl_renderbuffer * rb,GLenum datatype,GLuint count,GLint x,GLint y,const void * values,const GLubyte * mask)1067 _swrast_put_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1068 GLenum datatype,
1069 GLuint count, GLint x, GLint y,
1070 const void *values, const GLubyte *mask)
1071 {
1072 GLubyte *dst = _swrast_pixel_address(rb, x, y);
1073
1074 if (!mask) {
1075 if (datatype == GL_UNSIGNED_BYTE) {
1076 _mesa_pack_ubyte_rgba_row(rb->Format, count,
1077 (const GLubyte (*)[4]) values, dst);
1078 }
1079 else {
1080 assert(datatype == GL_FLOAT);
1081 _mesa_pack_float_rgba_row(rb->Format, count,
1082 (const GLfloat (*)[4]) values, dst);
1083 }
1084 }
1085 else {
1086 const GLuint bpp = _mesa_get_format_bytes(rb->Format);
1087 GLuint i, runLen, runStart;
1088 /* We can't pass a 'mask' array to the _mesa_pack_rgba_row() functions
1089 * so look for runs where mask=1...
1090 */
1091 runLen = runStart = 0;
1092 for (i = 0; i < count; i++) {
1093 if (mask[i]) {
1094 if (runLen == 0)
1095 runStart = i;
1096 runLen++;
1097 }
1098
1099 if (!mask[i] || i == count - 1) {
1100 /* might be the end of a run of pixels */
1101 if (runLen > 0) {
1102 if (datatype == GL_UNSIGNED_BYTE) {
1103 _mesa_pack_ubyte_rgba_row(rb->Format, runLen,
1104 (const GLubyte (*)[4]) values + runStart,
1105 dst + runStart * bpp);
1106 }
1107 else {
1108 assert(datatype == GL_FLOAT);
1109 _mesa_pack_float_rgba_row(rb->Format, runLen,
1110 (const GLfloat (*)[4]) values + runStart,
1111 dst + runStart * bpp);
1112 }
1113 runLen = 0;
1114 }
1115 }
1116 }
1117 }
1118 }
1119
1120
1121
1122 /**
1123 * Apply all the per-fragment operations to a span.
1124 * This now includes texturing (_swrast_write_texture_span() is history).
1125 * This function may modify any of the array values in the span.
1126 * span->interpMask and span->arrayMask may be changed but will be restored
1127 * to their original values before returning.
1128 */
1129 void
_swrast_write_rgba_span(struct gl_context * ctx,SWspan * span)1130 _swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)
1131 {
1132 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
1133 const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;
1134 const GLbitfield origInterpMask = span->interpMask;
1135 const GLbitfield origArrayMask = span->arrayMask;
1136 const GLbitfield64 origArrayAttribs = span->arrayAttribs;
1137 const GLenum origChanType = span->array->ChanType;
1138 void * const origRgba = span->array->rgba;
1139 const GLboolean shader = (_swrast_use_fragment_program(ctx)
1140 || ctx->ATIFragmentShader._Enabled);
1141 const GLboolean shaderOrTexture = shader || ctx->Texture._EnabledCoordUnits;
1142 struct gl_framebuffer *fb = ctx->DrawBuffer;
1143
1144 /*
1145 printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__,
1146 span->interpMask, span->arrayMask);
1147 */
1148
1149 ASSERT(span->primitive == GL_POINT ||
1150 span->primitive == GL_LINE ||
1151 span->primitive == GL_POLYGON ||
1152 span->primitive == GL_BITMAP);
1153
1154 /* Fragment write masks */
1155 if (span->arrayMask & SPAN_MASK) {
1156 /* mask was initialized by caller, probably glBitmap */
1157 span->writeAll = GL_FALSE;
1158 }
1159 else {
1160 memset(span->array->mask, 1, span->end);
1161 span->writeAll = GL_TRUE;
1162 }
1163
1164 /* Clip to window/scissor box */
1165 if (!clip_span(ctx, span)) {
1166 return;
1167 }
1168
1169 ASSERT(span->end <= SWRAST_MAX_WIDTH);
1170
1171 /* Depth bounds test */
1172 if (ctx->Depth.BoundsTest && fb->Visual.depthBits > 0) {
1173 if (!_swrast_depth_bounds_test(ctx, span)) {
1174 return;
1175 }
1176 }
1177
1178 #ifdef DEBUG
1179 /* Make sure all fragments are within window bounds */
1180 if (span->arrayMask & SPAN_XY) {
1181 /* array of pixel locations */
1182 GLuint i;
1183 for (i = 0; i < span->end; i++) {
1184 if (span->array->mask[i]) {
1185 assert(span->array->x[i] >= fb->_Xmin);
1186 assert(span->array->x[i] < fb->_Xmax);
1187 assert(span->array->y[i] >= fb->_Ymin);
1188 assert(span->array->y[i] < fb->_Ymax);
1189 }
1190 }
1191 }
1192 #endif
1193
1194 /* Polygon Stippling */
1195 if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
1196 stipple_polygon_span(ctx, span);
1197 }
1198
1199 /* This is the normal place to compute the fragment color/Z
1200 * from texturing or shading.
1201 */
1202 if (shaderOrTexture && !swrast->_DeferredTexture) {
1203 shade_texture_span(ctx, span);
1204 }
1205
1206 /* Do the alpha test */
1207 if (ctx->Color.AlphaEnabled) {
1208 if (!_swrast_alpha_test(ctx, span)) {
1209 /* all fragments failed test */
1210 goto end;
1211 }
1212 }
1213
1214 /* Stencil and Z testing */
1215 if (ctx->Stencil._Enabled || ctx->Depth.Test) {
1216 if (!(span->arrayMask & SPAN_Z))
1217 _swrast_span_interpolate_z(ctx, span);
1218
1219 if (ctx->Transform.DepthClamp)
1220 _swrast_depth_clamp_span(ctx, span);
1221
1222 if (ctx->Stencil._Enabled) {
1223 /* Combined Z/stencil tests */
1224 if (!_swrast_stencil_and_ztest_span(ctx, span)) {
1225 /* all fragments failed test */
1226 goto end;
1227 }
1228 }
1229 else if (fb->Visual.depthBits > 0) {
1230 /* Just regular depth testing */
1231 ASSERT(ctx->Depth.Test);
1232 ASSERT(span->arrayMask & SPAN_Z);
1233 if (!_swrast_depth_test_span(ctx, span)) {
1234 /* all fragments failed test */
1235 goto end;
1236 }
1237 }
1238 }
1239
1240 if (ctx->Query.CurrentOcclusionObject) {
1241 /* update count of 'passed' fragments */
1242 struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
1243 GLuint i;
1244 for (i = 0; i < span->end; i++)
1245 q->Result += span->array->mask[i];
1246 }
1247
1248 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1249 * the occlusion test.
1250 */
1251 if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {
1252 /* no colors to write */
1253 goto end;
1254 }
1255
1256 /* If we were able to defer fragment color computation to now, there's
1257 * a good chance that many fragments will have already been killed by
1258 * Z/stencil testing.
1259 */
1260 if (shaderOrTexture && swrast->_DeferredTexture) {
1261 shade_texture_span(ctx, span);
1262 }
1263
1264 #if CHAN_BITS == 32
1265 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
1266 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
1267 }
1268 #else
1269 if ((span->arrayMask & SPAN_RGBA) == 0) {
1270 interpolate_int_colors(ctx, span);
1271 }
1272 #endif
1273
1274 ASSERT(span->arrayMask & SPAN_RGBA);
1275
1276 if (span->primitive == GL_BITMAP || !swrast->SpecularVertexAdd) {
1277 /* Add primary and specular (diffuse + specular) colors */
1278 if (!shader) {
1279 if (ctx->Fog.ColorSumEnabled ||
1280 (ctx->Light.Enabled &&
1281 ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {
1282 add_specular(ctx, span);
1283 }
1284 }
1285 }
1286
1287 /* Fog */
1288 if (swrast->_FogEnabled) {
1289 _swrast_fog_rgba_span(ctx, span);
1290 }
1291
1292 /* Antialias coverage application */
1293 if (span->arrayMask & SPAN_COVERAGE) {
1294 apply_aa_coverage(span);
1295 }
1296
1297 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1298 if (ctx->Color.ClampFragmentColor == GL_TRUE &&
1299 span->array->ChanType == GL_FLOAT) {
1300 clamp_colors(span);
1301 }
1302
1303 /*
1304 * Write to renderbuffers.
1305 * Depending on glDrawBuffer() state and the which color outputs are
1306 * written by the fragment shader, we may either replicate one color to
1307 * all renderbuffers or write a different color to each renderbuffer.
1308 * multiFragOutputs=TRUE for the later case.
1309 */
1310 {
1311 const GLuint numBuffers = fb->_NumColorDrawBuffers;
1312 const struct gl_fragment_program *fp = ctx->FragmentProgram._Current;
1313 const GLboolean multiFragOutputs =
1314 _swrast_use_fragment_program(ctx)
1315 && fp->Base.OutputsWritten >= (1 << FRAG_RESULT_DATA0);
1316 GLuint buf;
1317
1318 for (buf = 0; buf < numBuffers; buf++) {
1319 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];
1320
1321 /* color[fragOutput] will be written to buffer[buf] */
1322
1323 if (rb) {
1324 /* re-use one of the attribute array buffers for rgbaSave */
1325 GLchan (*rgbaSave)[4] = (GLchan (*)[4]) span->array->attribs[0];
1326 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
1327 GLenum colorType = srb->ColorType;
1328
1329 assert(colorType == GL_UNSIGNED_BYTE ||
1330 colorType == GL_FLOAT);
1331
1332 /* set span->array->rgba to colors for renderbuffer's datatype */
1333 if (span->array->ChanType != colorType) {
1334 convert_color_type(span, colorType, 0);
1335 }
1336 else {
1337 if (span->array->ChanType == GL_UNSIGNED_BYTE) {
1338 span->array->rgba = span->array->rgba8;
1339 }
1340 else {
1341 span->array->rgba = (void *)
1342 span->array->attribs[FRAG_ATTRIB_COL0];
1343 }
1344 }
1345
1346 if (!multiFragOutputs && numBuffers > 1) {
1347 /* save colors for second, third renderbuffer writes */
1348 memcpy(rgbaSave, span->array->rgba,
1349 4 * span->end * sizeof(GLchan));
1350 }
1351
1352 ASSERT(rb->_BaseFormat == GL_RGBA ||
1353 rb->_BaseFormat == GL_RGB ||
1354 rb->_BaseFormat == GL_RED ||
1355 rb->_BaseFormat == GL_RG ||
1356 rb->_BaseFormat == GL_ALPHA);
1357
1358 if (ctx->Color.ColorLogicOpEnabled) {
1359 _swrast_logicop_rgba_span(ctx, rb, span);
1360 }
1361 else if ((ctx->Color.BlendEnabled >> buf) & 1) {
1362 _swrast_blend_span(ctx, rb, span);
1363 }
1364
1365 if (colorMask[buf] != 0xffffffff) {
1366 _swrast_mask_rgba_span(ctx, rb, span, buf);
1367 }
1368
1369 if (span->arrayMask & SPAN_XY) {
1370 /* array of pixel coords */
1371 put_values(ctx, rb,
1372 span->array->ChanType, span->end,
1373 span->array->x, span->array->y,
1374 span->array->rgba, span->array->mask);
1375 }
1376 else {
1377 /* horizontal run of pixels */
1378 _swrast_put_row(ctx, rb,
1379 span->array->ChanType,
1380 span->end, span->x, span->y,
1381 span->array->rgba,
1382 span->writeAll ? NULL: span->array->mask);
1383 }
1384
1385 if (!multiFragOutputs && numBuffers > 1) {
1386 /* restore original span values */
1387 memcpy(span->array->rgba, rgbaSave,
1388 4 * span->end * sizeof(GLchan));
1389 }
1390
1391 } /* if rb */
1392 } /* for buf */
1393 }
1394
1395 end:
1396 /* restore these values before returning */
1397 span->interpMask = origInterpMask;
1398 span->arrayMask = origArrayMask;
1399 span->arrayAttribs = origArrayAttribs;
1400 span->array->ChanType = origChanType;
1401 span->array->rgba = origRgba;
1402 }
1403
1404
1405 /**
1406 * Read float RGBA pixels from a renderbuffer. Clipping will be done to
1407 * prevent reading ouside the buffer's boundaries.
1408 * \param rgba the returned colors
1409 */
1410 void
_swrast_read_rgba_span(struct gl_context * ctx,struct gl_renderbuffer * rb,GLuint n,GLint x,GLint y,GLvoid * rgba)1411 _swrast_read_rgba_span( struct gl_context *ctx, struct gl_renderbuffer *rb,
1412 GLuint n, GLint x, GLint y,
1413 GLvoid *rgba)
1414 {
1415 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
1416 GLenum dstType = GL_FLOAT;
1417 const GLint bufWidth = (GLint) rb->Width;
1418 const GLint bufHeight = (GLint) rb->Height;
1419
1420 if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
1421 /* completely above, below, or right */
1422 /* XXX maybe leave rgba values undefined? */
1423 memset(rgba, 0, 4 * n * sizeof(GLchan));
1424 }
1425 else {
1426 GLint skip, length;
1427 GLubyte *src;
1428
1429 if (x < 0) {
1430 /* left edge clipping */
1431 skip = -x;
1432 length = (GLint) n - skip;
1433 if (length < 0) {
1434 /* completely left of window */
1435 return;
1436 }
1437 if (length > bufWidth) {
1438 length = bufWidth;
1439 }
1440 }
1441 else if ((GLint) (x + n) > bufWidth) {
1442 /* right edge clipping */
1443 skip = 0;
1444 length = bufWidth - x;
1445 if (length < 0) {
1446 /* completely to right of window */
1447 return;
1448 }
1449 }
1450 else {
1451 /* no clipping */
1452 skip = 0;
1453 length = (GLint) n;
1454 }
1455
1456 ASSERT(rb);
1457 ASSERT(rb->_BaseFormat == GL_RGBA ||
1458 rb->_BaseFormat == GL_RGB ||
1459 rb->_BaseFormat == GL_RG ||
1460 rb->_BaseFormat == GL_RED ||
1461 rb->_BaseFormat == GL_LUMINANCE ||
1462 rb->_BaseFormat == GL_INTENSITY ||
1463 rb->_BaseFormat == GL_LUMINANCE_ALPHA ||
1464 rb->_BaseFormat == GL_ALPHA);
1465
1466 assert(srb->Map);
1467
1468 src = _swrast_pixel_address(rb, x + skip, y);
1469
1470 if (dstType == GL_UNSIGNED_BYTE) {
1471 _mesa_unpack_ubyte_rgba_row(rb->Format, length, src,
1472 (GLubyte (*)[4]) rgba + skip);
1473 }
1474 else if (dstType == GL_FLOAT) {
1475 _mesa_unpack_rgba_row(rb->Format, length, src,
1476 (GLfloat (*)[4]) rgba + skip);
1477 }
1478 else {
1479 _mesa_problem(ctx, "unexpected type in _swrast_read_rgba_span()");
1480 }
1481 }
1482 }
1483
1484
1485 /**
1486 * Get colors at x/y positions with clipping.
1487 * \param type type of values to return
1488 */
1489 static void
get_values(struct gl_context * ctx,struct gl_renderbuffer * rb,GLuint count,const GLint x[],const GLint y[],void * values,GLenum type)1490 get_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1491 GLuint count, const GLint x[], const GLint y[],
1492 void *values, GLenum type)
1493 {
1494 GLuint i;
1495
1496 for (i = 0; i < count; i++) {
1497 if (x[i] >= 0 && y[i] >= 0 &&
1498 x[i] < (GLint) rb->Width && y[i] < (GLint) rb->Height) {
1499 /* inside */
1500 const GLubyte *src = _swrast_pixel_address(rb, x[i], y[i]);
1501
1502 if (type == GL_UNSIGNED_BYTE) {
1503 _mesa_unpack_ubyte_rgba_row(rb->Format, 1, src,
1504 (GLubyte (*)[4]) values + i);
1505 }
1506 else if (type == GL_FLOAT) {
1507 _mesa_unpack_rgba_row(rb->Format, 1, src,
1508 (GLfloat (*)[4]) values + i);
1509 }
1510 else {
1511 _mesa_problem(ctx, "unexpected type in get_values()");
1512 }
1513 }
1514 }
1515 }
1516
1517
1518 /**
1519 * Get row of colors with clipping.
1520 * \param type type of values to return
1521 */
1522 static void
get_row(struct gl_context * ctx,struct gl_renderbuffer * rb,GLuint count,GLint x,GLint y,GLvoid * values,GLenum type)1523 get_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1524 GLuint count, GLint x, GLint y,
1525 GLvoid *values, GLenum type)
1526 {
1527 GLint skip = 0;
1528 GLubyte *src;
1529
1530 if (y < 0 || y >= (GLint) rb->Height)
1531 return; /* above or below */
1532
1533 if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
1534 return; /* entirely left or right */
1535
1536 if (x + count > rb->Width) {
1537 /* right clip */
1538 GLint clip = x + count - rb->Width;
1539 count -= clip;
1540 }
1541
1542 if (x < 0) {
1543 /* left clip */
1544 skip = -x;
1545 x = 0;
1546 count -= skip;
1547 }
1548
1549 src = _swrast_pixel_address(rb, x, y);
1550
1551 if (type == GL_UNSIGNED_BYTE) {
1552 _mesa_unpack_ubyte_rgba_row(rb->Format, count, src,
1553 (GLubyte (*)[4]) values + skip);
1554 }
1555 else if (type == GL_FLOAT) {
1556 _mesa_unpack_rgba_row(rb->Format, count, src,
1557 (GLfloat (*)[4]) values + skip);
1558 }
1559 else {
1560 _mesa_problem(ctx, "unexpected type in get_row()");
1561 }
1562 }
1563
1564
1565 /**
1566 * Get RGBA pixels from the given renderbuffer.
1567 * Used by blending, logicop and masking functions.
1568 * \return pointer to the colors we read.
1569 */
1570 void *
_swrast_get_dest_rgba(struct gl_context * ctx,struct gl_renderbuffer * rb,SWspan * span)1571 _swrast_get_dest_rgba(struct gl_context *ctx, struct gl_renderbuffer *rb,
1572 SWspan *span)
1573 {
1574 void *rbPixels;
1575
1576 /* Point rbPixels to a temporary space */
1577 rbPixels = span->array->attribs[FRAG_ATTRIB_MAX - 1];
1578
1579 /* Get destination values from renderbuffer */
1580 if (span->arrayMask & SPAN_XY) {
1581 get_values(ctx, rb, span->end, span->array->x, span->array->y,
1582 rbPixels, span->array->ChanType);
1583 }
1584 else {
1585 get_row(ctx, rb, span->end, span->x, span->y,
1586 rbPixels, span->array->ChanType);
1587 }
1588
1589 return rbPixels;
1590 }
1591