1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
5 * Copyright (C) 2009 VMware, Inc. All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 * OTHER DEALINGS IN THE SOFTWARE.
24 */
25
26
27 /**
28 * \file swrast/s_span.c
29 * \brief Span processing functions used by all rasterization functions.
30 * This is where all the per-fragment tests are performed
31 * \author Brian Paul
32 */
33
34 #include "c99_math.h"
35 #include "main/glheader.h"
36 #include "main/format_pack.h"
37 #include "main/format_unpack.h"
38 #include "main/macros.h"
39 #include "main/imports.h"
40 #include "main/image.h"
41 #include "main/samplerobj.h"
42 #include "main/state.h"
43 #include "main/stencil.h"
44 #include "main/teximage.h"
45
46 #include "s_atifragshader.h"
47 #include "s_alpha.h"
48 #include "s_blend.h"
49 #include "s_context.h"
50 #include "s_depth.h"
51 #include "s_fog.h"
52 #include "s_logic.h"
53 #include "s_masking.h"
54 #include "s_fragprog.h"
55 #include "s_span.h"
56 #include "s_stencil.h"
57 #include "s_texcombine.h"
58
59 #include <stdbool.h>
60
61 /**
62 * Set default fragment attributes for the span using the
63 * current raster values. Used prior to glDraw/CopyPixels
64 * and glBitmap.
65 */
66 void
_swrast_span_default_attribs(struct gl_context * ctx,SWspan * span)67 _swrast_span_default_attribs(struct gl_context *ctx, SWspan *span)
68 {
69 GLchan r, g, b, a;
70 /* Z*/
71 {
72 const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;
73 if (ctx->DrawBuffer->Visual.depthBits <= 16)
74 span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);
75 else {
76 GLfloat tmpf = ctx->Current.RasterPos[2] * depthMax;
77 tmpf = MIN2(tmpf, depthMax);
78 span->z = (GLint)tmpf;
79 }
80 span->zStep = 0;
81 span->interpMask |= SPAN_Z;
82 }
83
84 /* W (for perspective correction) */
85 span->attrStart[VARYING_SLOT_POS][3] = 1.0;
86 span->attrStepX[VARYING_SLOT_POS][3] = 0.0;
87 span->attrStepY[VARYING_SLOT_POS][3] = 0.0;
88
89 /* primary color, or color index */
90 UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);
91 UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);
92 UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);
93 UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);
94 #if CHAN_TYPE == GL_FLOAT
95 span->red = r;
96 span->green = g;
97 span->blue = b;
98 span->alpha = a;
99 #else
100 span->red = IntToFixed(r);
101 span->green = IntToFixed(g);
102 span->blue = IntToFixed(b);
103 span->alpha = IntToFixed(a);
104 #endif
105 span->redStep = 0;
106 span->greenStep = 0;
107 span->blueStep = 0;
108 span->alphaStep = 0;
109 span->interpMask |= SPAN_RGBA;
110
111 COPY_4V(span->attrStart[VARYING_SLOT_COL0], ctx->Current.RasterColor);
112 ASSIGN_4V(span->attrStepX[VARYING_SLOT_COL0], 0.0, 0.0, 0.0, 0.0);
113 ASSIGN_4V(span->attrStepY[VARYING_SLOT_COL0], 0.0, 0.0, 0.0, 0.0);
114
115 /* Secondary color */
116 if (ctx->Light.Enabled || ctx->Fog.ColorSumEnabled)
117 {
118 COPY_4V(span->attrStart[VARYING_SLOT_COL1], ctx->Current.RasterSecondaryColor);
119 ASSIGN_4V(span->attrStepX[VARYING_SLOT_COL1], 0.0, 0.0, 0.0, 0.0);
120 ASSIGN_4V(span->attrStepY[VARYING_SLOT_COL1], 0.0, 0.0, 0.0, 0.0);
121 }
122
123 /* fog */
124 {
125 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
126 GLfloat fogVal; /* a coord or a blend factor */
127 if (swrast->_PreferPixelFog) {
128 /* fog blend factors will be computed from fog coordinates per pixel */
129 fogVal = ctx->Current.RasterDistance;
130 }
131 else {
132 /* fog blend factor should be computed from fogcoord now */
133 fogVal = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);
134 }
135 span->attrStart[VARYING_SLOT_FOGC][0] = fogVal;
136 span->attrStepX[VARYING_SLOT_FOGC][0] = 0.0;
137 span->attrStepY[VARYING_SLOT_FOGC][0] = 0.0;
138 }
139
140 /* texcoords */
141 {
142 GLuint i;
143 for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
144 const GLuint attr = VARYING_SLOT_TEX0 + i;
145 const GLfloat *tc = ctx->Current.RasterTexCoords[i];
146 if (_swrast_use_fragment_program(ctx) ||
147 _mesa_ati_fragment_shader_enabled(ctx)) {
148 COPY_4V(span->attrStart[attr], tc);
149 }
150 else if (tc[3] > 0.0F) {
151 /* use (s/q, t/q, r/q, 1) */
152 span->attrStart[attr][0] = tc[0] / tc[3];
153 span->attrStart[attr][1] = tc[1] / tc[3];
154 span->attrStart[attr][2] = tc[2] / tc[3];
155 span->attrStart[attr][3] = 1.0;
156 }
157 else {
158 ASSIGN_4V(span->attrStart[attr], 0.0F, 0.0F, 0.0F, 1.0F);
159 }
160 ASSIGN_4V(span->attrStepX[attr], 0.0F, 0.0F, 0.0F, 0.0F);
161 ASSIGN_4V(span->attrStepY[attr], 0.0F, 0.0F, 0.0F, 0.0F);
162 }
163 }
164 }
165
166
167 /**
168 * Interpolate the active attributes (and'd with attrMask) to
169 * fill in span->array->attribs[].
170 * Perspective correction will be done. The point/line/triangle function
171 * should have computed attrStart/Step values for VARYING_SLOT_POS[3]!
172 */
173 static inline void
interpolate_active_attribs(struct gl_context * ctx,SWspan * span,GLbitfield64 attrMask)174 interpolate_active_attribs(struct gl_context *ctx, SWspan *span,
175 GLbitfield64 attrMask)
176 {
177 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
178
179 /*
180 * Don't overwrite existing array values, such as colors that may have
181 * been produced by glDraw/CopyPixels.
182 */
183 attrMask &= ~span->arrayAttribs;
184
185 ATTRIB_LOOP_BEGIN
186 if (attrMask & BITFIELD64_BIT(attr)) {
187 const GLfloat dwdx = span->attrStepX[VARYING_SLOT_POS][3];
188 GLfloat w = span->attrStart[VARYING_SLOT_POS][3];
189 const GLfloat dv0dx = span->attrStepX[attr][0];
190 const GLfloat dv1dx = span->attrStepX[attr][1];
191 const GLfloat dv2dx = span->attrStepX[attr][2];
192 const GLfloat dv3dx = span->attrStepX[attr][3];
193 GLfloat v0 = span->attrStart[attr][0] + span->leftClip * dv0dx;
194 GLfloat v1 = span->attrStart[attr][1] + span->leftClip * dv1dx;
195 GLfloat v2 = span->attrStart[attr][2] + span->leftClip * dv2dx;
196 GLfloat v3 = span->attrStart[attr][3] + span->leftClip * dv3dx;
197 GLuint k;
198 for (k = 0; k < span->end; k++) {
199 const GLfloat invW = 1.0f / w;
200 span->array->attribs[attr][k][0] = v0 * invW;
201 span->array->attribs[attr][k][1] = v1 * invW;
202 span->array->attribs[attr][k][2] = v2 * invW;
203 span->array->attribs[attr][k][3] = v3 * invW;
204 v0 += dv0dx;
205 v1 += dv1dx;
206 v2 += dv2dx;
207 v3 += dv3dx;
208 w += dwdx;
209 }
210 assert((span->arrayAttribs & BITFIELD64_BIT(attr)) == 0);
211 span->arrayAttribs |= BITFIELD64_BIT(attr);
212 }
213 ATTRIB_LOOP_END
214 }
215
216
217 /**
218 * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
219 * color array.
220 */
221 static inline void
interpolate_int_colors(struct gl_context * ctx,SWspan * span)222 interpolate_int_colors(struct gl_context *ctx, SWspan *span)
223 {
224 #if CHAN_BITS != 32
225 const GLuint n = span->end;
226 GLuint i;
227
228 assert(!(span->arrayMask & SPAN_RGBA));
229 #endif
230
231 switch (span->array->ChanType) {
232 #if CHAN_BITS != 32
233 case GL_UNSIGNED_BYTE:
234 {
235 GLubyte (*rgba)[4] = span->array->rgba8;
236 if (span->interpMask & SPAN_FLAT) {
237 GLubyte color[4];
238 color[RCOMP] = FixedToInt(span->red);
239 color[GCOMP] = FixedToInt(span->green);
240 color[BCOMP] = FixedToInt(span->blue);
241 color[ACOMP] = FixedToInt(span->alpha);
242 for (i = 0; i < n; i++) {
243 COPY_4UBV(rgba[i], color);
244 }
245 }
246 else {
247 GLfixed r = span->red;
248 GLfixed g = span->green;
249 GLfixed b = span->blue;
250 GLfixed a = span->alpha;
251 GLint dr = span->redStep;
252 GLint dg = span->greenStep;
253 GLint db = span->blueStep;
254 GLint da = span->alphaStep;
255 for (i = 0; i < n; i++) {
256 rgba[i][RCOMP] = FixedToChan(r);
257 rgba[i][GCOMP] = FixedToChan(g);
258 rgba[i][BCOMP] = FixedToChan(b);
259 rgba[i][ACOMP] = FixedToChan(a);
260 r += dr;
261 g += dg;
262 b += db;
263 a += da;
264 }
265 }
266 }
267 break;
268 case GL_UNSIGNED_SHORT:
269 {
270 GLushort (*rgba)[4] = span->array->rgba16;
271 if (span->interpMask & SPAN_FLAT) {
272 GLushort color[4];
273 color[RCOMP] = FixedToInt(span->red);
274 color[GCOMP] = FixedToInt(span->green);
275 color[BCOMP] = FixedToInt(span->blue);
276 color[ACOMP] = FixedToInt(span->alpha);
277 for (i = 0; i < n; i++) {
278 COPY_4V(rgba[i], color);
279 }
280 }
281 else {
282 GLushort (*rgba)[4] = span->array->rgba16;
283 GLfixed r, g, b, a;
284 GLint dr, dg, db, da;
285 r = span->red;
286 g = span->green;
287 b = span->blue;
288 a = span->alpha;
289 dr = span->redStep;
290 dg = span->greenStep;
291 db = span->blueStep;
292 da = span->alphaStep;
293 for (i = 0; i < n; i++) {
294 rgba[i][RCOMP] = FixedToChan(r);
295 rgba[i][GCOMP] = FixedToChan(g);
296 rgba[i][BCOMP] = FixedToChan(b);
297 rgba[i][ACOMP] = FixedToChan(a);
298 r += dr;
299 g += dg;
300 b += db;
301 a += da;
302 }
303 }
304 }
305 break;
306 #endif
307 case GL_FLOAT:
308 interpolate_active_attribs(ctx, span, VARYING_BIT_COL0);
309 break;
310 default:
311 _mesa_problem(ctx, "bad datatype 0x%x in interpolate_int_colors",
312 span->array->ChanType);
313 }
314 span->arrayMask |= SPAN_RGBA;
315 }
316
317
318 /**
319 * Populate the VARYING_SLOT_COL0 array.
320 */
321 static inline void
interpolate_float_colors(SWspan * span)322 interpolate_float_colors(SWspan *span)
323 {
324 GLfloat (*col0)[4] = span->array->attribs[VARYING_SLOT_COL0];
325 const GLuint n = span->end;
326 GLuint i;
327
328 assert(!(span->arrayAttribs & VARYING_BIT_COL0));
329
330 if (span->arrayMask & SPAN_RGBA) {
331 /* convert array of int colors */
332 for (i = 0; i < n; i++) {
333 col0[i][0] = UBYTE_TO_FLOAT(span->array->rgba8[i][0]);
334 col0[i][1] = UBYTE_TO_FLOAT(span->array->rgba8[i][1]);
335 col0[i][2] = UBYTE_TO_FLOAT(span->array->rgba8[i][2]);
336 col0[i][3] = UBYTE_TO_FLOAT(span->array->rgba8[i][3]);
337 }
338 }
339 else {
340 /* interpolate red/green/blue/alpha to get float colors */
341 assert(span->interpMask & SPAN_RGBA);
342 if (span->interpMask & SPAN_FLAT) {
343 GLfloat r = FixedToFloat(span->red);
344 GLfloat g = FixedToFloat(span->green);
345 GLfloat b = FixedToFloat(span->blue);
346 GLfloat a = FixedToFloat(span->alpha);
347 for (i = 0; i < n; i++) {
348 ASSIGN_4V(col0[i], r, g, b, a);
349 }
350 }
351 else {
352 GLfloat r = FixedToFloat(span->red);
353 GLfloat g = FixedToFloat(span->green);
354 GLfloat b = FixedToFloat(span->blue);
355 GLfloat a = FixedToFloat(span->alpha);
356 GLfloat dr = FixedToFloat(span->redStep);
357 GLfloat dg = FixedToFloat(span->greenStep);
358 GLfloat db = FixedToFloat(span->blueStep);
359 GLfloat da = FixedToFloat(span->alphaStep);
360 for (i = 0; i < n; i++) {
361 col0[i][0] = r;
362 col0[i][1] = g;
363 col0[i][2] = b;
364 col0[i][3] = a;
365 r += dr;
366 g += dg;
367 b += db;
368 a += da;
369 }
370 }
371 }
372
373 span->arrayAttribs |= VARYING_BIT_COL0;
374 span->array->ChanType = GL_FLOAT;
375 }
376
377
378
379 /**
380 * Fill in the span.zArray array from the span->z, zStep values.
381 */
382 void
_swrast_span_interpolate_z(const struct gl_context * ctx,SWspan * span)383 _swrast_span_interpolate_z( const struct gl_context *ctx, SWspan *span )
384 {
385 const GLuint n = span->end;
386 GLuint i;
387
388 assert(!(span->arrayMask & SPAN_Z));
389
390 if (ctx->DrawBuffer->Visual.depthBits <= 16) {
391 GLfixed zval = span->z;
392 GLuint *z = span->array->z;
393 for (i = 0; i < n; i++) {
394 z[i] = FixedToInt(zval);
395 zval += span->zStep;
396 }
397 }
398 else {
399 /* Deep Z buffer, no fixed->int shift */
400 GLuint zval = span->z;
401 GLuint *z = span->array->z;
402 for (i = 0; i < n; i++) {
403 z[i] = zval;
404 zval += span->zStep;
405 }
406 }
407 span->interpMask &= ~SPAN_Z;
408 span->arrayMask |= SPAN_Z;
409 }
410
411
412 /**
413 * Compute mipmap LOD from partial derivatives.
414 * This the ideal solution, as given in the OpenGL spec.
415 */
416 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)417 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
418 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
419 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
420 {
421 GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);
422 GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);
423 GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);
424 GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);
425 GLfloat x = sqrtf(dudx * dudx + dvdx * dvdx);
426 GLfloat y = sqrtf(dudy * dudy + dvdy * dvdy);
427 GLfloat rho = MAX2(x, y);
428 GLfloat lambda = LOG2(rho);
429 return lambda;
430 }
431
432
433 /**
434 * Compute mipmap LOD from partial derivatives.
435 * This is a faster approximation than above function.
436 */
437 #if 0
438 GLfloat
439 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
440 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
441 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
442 {
443 GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;
444 GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;
445 GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;
446 GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;
447 GLfloat maxU, maxV, rho, lambda;
448 dsdx2 = fabsf(dsdx2);
449 dsdy2 = fabsf(dsdy2);
450 dtdx2 = fabsf(dtdx2);
451 dtdy2 = fabsf(dtdy2);
452 maxU = MAX2(dsdx2, dsdy2) * texW;
453 maxV = MAX2(dtdx2, dtdy2) * texH;
454 rho = MAX2(maxU, maxV);
455 lambda = LOG2(rho);
456 return lambda;
457 }
458 #endif
459
460
461 /**
462 * Fill in the span.array->attrib[VARYING_SLOT_TEXn] arrays from the
463 * using the attrStart/Step values.
464 *
465 * This function only used during fixed-function fragment processing.
466 *
467 * Note: in the places where we divide by Q (or mult by invQ) we're
468 * really doing two things: perspective correction and texcoord
469 * projection. Remember, for texcoord (s,t,r,q) we need to index
470 * texels with (s/q, t/q, r/q).
471 */
472 static void
interpolate_texcoords(struct gl_context * ctx,SWspan * span)473 interpolate_texcoords(struct gl_context *ctx, SWspan *span)
474 {
475 const GLuint maxUnit
476 = (ctx->Texture._EnabledCoordUnits > 1) ? ctx->Const.MaxTextureUnits : 1;
477 GLuint u;
478
479 /* XXX CoordUnits vs. ImageUnits */
480 for (u = 0; u < maxUnit; u++) {
481 if (ctx->Texture._EnabledCoordUnits & (1 << u)) {
482 const GLuint attr = VARYING_SLOT_TEX0 + u;
483 const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
484 GLfloat texW, texH;
485 GLboolean needLambda;
486 GLfloat (*texcoord)[4] = span->array->attribs[attr];
487 GLfloat *lambda = span->array->lambda[u];
488 const GLfloat dsdx = span->attrStepX[attr][0];
489 const GLfloat dsdy = span->attrStepY[attr][0];
490 const GLfloat dtdx = span->attrStepX[attr][1];
491 const GLfloat dtdy = span->attrStepY[attr][1];
492 const GLfloat drdx = span->attrStepX[attr][2];
493 const GLfloat dqdx = span->attrStepX[attr][3];
494 const GLfloat dqdy = span->attrStepY[attr][3];
495 GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx;
496 GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx;
497 GLfloat r = span->attrStart[attr][2] + span->leftClip * drdx;
498 GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx;
499
500 if (obj) {
501 const struct gl_texture_image *img = _mesa_base_tex_image(obj);
502 const struct swrast_texture_image *swImg =
503 swrast_texture_image_const(img);
504 const struct gl_sampler_object *samp = _mesa_get_samplerobj(ctx, u);
505
506 needLambda = (samp->MinFilter != samp->MagFilter)
507 || _swrast_use_fragment_program(ctx);
508 /* LOD is calculated directly in the ansiotropic filter, we can
509 * skip the normal lambda function as the result is ignored.
510 */
511 if (samp->MaxAnisotropy > 1.0F &&
512 samp->MinFilter == GL_LINEAR_MIPMAP_LINEAR) {
513 needLambda = GL_FALSE;
514 }
515 texW = swImg->WidthScale;
516 texH = swImg->HeightScale;
517 }
518 else {
519 /* using a fragment program */
520 texW = 1.0;
521 texH = 1.0;
522 needLambda = GL_FALSE;
523 }
524
525 if (needLambda) {
526 GLuint i;
527 if (_swrast_use_fragment_program(ctx)
528 || _mesa_ati_fragment_shader_enabled(ctx)) {
529 /* do perspective correction but don't divide s, t, r by q */
530 const GLfloat dwdx = span->attrStepX[VARYING_SLOT_POS][3];
531 GLfloat w = span->attrStart[VARYING_SLOT_POS][3] + span->leftClip * dwdx;
532 for (i = 0; i < span->end; i++) {
533 const GLfloat invW = 1.0F / w;
534 texcoord[i][0] = s * invW;
535 texcoord[i][1] = t * invW;
536 texcoord[i][2] = r * invW;
537 texcoord[i][3] = q * invW;
538 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
539 dqdx, dqdy, texW, texH,
540 s, t, q, invW);
541 s += dsdx;
542 t += dtdx;
543 r += drdx;
544 q += dqdx;
545 w += dwdx;
546 }
547 }
548 else {
549 for (i = 0; i < span->end; i++) {
550 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
551 texcoord[i][0] = s * invQ;
552 texcoord[i][1] = t * invQ;
553 texcoord[i][2] = r * invQ;
554 texcoord[i][3] = q;
555 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
556 dqdx, dqdy, texW, texH,
557 s, t, q, invQ);
558 s += dsdx;
559 t += dtdx;
560 r += drdx;
561 q += dqdx;
562 }
563 }
564 span->arrayMask |= SPAN_LAMBDA;
565 }
566 else {
567 GLuint i;
568 if (_swrast_use_fragment_program(ctx) ||
569 _mesa_ati_fragment_shader_enabled(ctx)) {
570 /* do perspective correction but don't divide s, t, r by q */
571 const GLfloat dwdx = span->attrStepX[VARYING_SLOT_POS][3];
572 GLfloat w = span->attrStart[VARYING_SLOT_POS][3] + span->leftClip * dwdx;
573 for (i = 0; i < span->end; i++) {
574 const GLfloat invW = 1.0F / w;
575 texcoord[i][0] = s * invW;
576 texcoord[i][1] = t * invW;
577 texcoord[i][2] = r * invW;
578 texcoord[i][3] = q * invW;
579 lambda[i] = 0.0;
580 s += dsdx;
581 t += dtdx;
582 r += drdx;
583 q += dqdx;
584 w += dwdx;
585 }
586 }
587 else if (dqdx == 0.0F) {
588 /* Ortho projection or polygon's parallel to window X axis */
589 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
590 for (i = 0; i < span->end; i++) {
591 texcoord[i][0] = s * invQ;
592 texcoord[i][1] = t * invQ;
593 texcoord[i][2] = r * invQ;
594 texcoord[i][3] = q;
595 lambda[i] = 0.0;
596 s += dsdx;
597 t += dtdx;
598 r += drdx;
599 }
600 }
601 else {
602 for (i = 0; i < span->end; i++) {
603 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
604 texcoord[i][0] = s * invQ;
605 texcoord[i][1] = t * invQ;
606 texcoord[i][2] = r * invQ;
607 texcoord[i][3] = q;
608 lambda[i] = 0.0;
609 s += dsdx;
610 t += dtdx;
611 r += drdx;
612 q += dqdx;
613 }
614 }
615 } /* lambda */
616 } /* if */
617 } /* for */
618 }
619
620
621 /**
622 * Fill in the arrays->attribs[VARYING_SLOT_POS] array.
623 */
624 static inline void
interpolate_wpos(struct gl_context * ctx,SWspan * span)625 interpolate_wpos(struct gl_context *ctx, SWspan *span)
626 {
627 GLfloat (*wpos)[4] = span->array->attribs[VARYING_SLOT_POS];
628 GLuint i;
629 const GLfloat zScale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
630 GLfloat w, dw;
631
632 if (span->arrayMask & SPAN_XY) {
633 for (i = 0; i < span->end; i++) {
634 wpos[i][0] = (GLfloat) span->array->x[i];
635 wpos[i][1] = (GLfloat) span->array->y[i];
636 }
637 }
638 else {
639 for (i = 0; i < span->end; i++) {
640 wpos[i][0] = (GLfloat) span->x + i;
641 wpos[i][1] = (GLfloat) span->y;
642 }
643 }
644
645 dw = span->attrStepX[VARYING_SLOT_POS][3];
646 w = span->attrStart[VARYING_SLOT_POS][3] + span->leftClip * dw;
647 for (i = 0; i < span->end; i++) {
648 wpos[i][2] = (GLfloat) span->array->z[i] * zScale;
649 wpos[i][3] = w;
650 w += dw;
651 }
652 }
653
654
655 /**
656 * Apply the current polygon stipple pattern to a span of pixels.
657 */
658 static inline void
stipple_polygon_span(struct gl_context * ctx,SWspan * span)659 stipple_polygon_span(struct gl_context *ctx, SWspan *span)
660 {
661 GLubyte *mask = span->array->mask;
662
663 assert(ctx->Polygon.StippleFlag);
664
665 if (span->arrayMask & SPAN_XY) {
666 /* arrays of x/y pixel coords */
667 GLuint i;
668 for (i = 0; i < span->end; i++) {
669 const GLint col = span->array->x[i] % 32;
670 const GLint row = span->array->y[i] % 32;
671 const GLuint stipple = ctx->PolygonStipple[row];
672 if (((1 << col) & stipple) == 0) {
673 mask[i] = 0;
674 }
675 }
676 }
677 else {
678 /* horizontal span of pixels */
679 const GLuint highBit = 1 << 31;
680 const GLuint stipple = ctx->PolygonStipple[span->y % 32];
681 GLuint i, m = highBit >> (GLuint) (span->x % 32);
682 for (i = 0; i < span->end; i++) {
683 if ((m & stipple) == 0) {
684 mask[i] = 0;
685 }
686 m = m >> 1;
687 if (m == 0) {
688 m = highBit;
689 }
690 }
691 }
692 span->writeAll = GL_FALSE;
693 }
694
695
696 /**
697 * Clip a pixel span to the current buffer/window boundaries:
698 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
699 * window clipping and scissoring.
700 * Return: GL_TRUE some pixels still visible
701 * GL_FALSE nothing visible
702 */
703 static inline GLuint
clip_span(struct gl_context * ctx,SWspan * span)704 clip_span( struct gl_context *ctx, SWspan *span )
705 {
706 const GLint xmin = ctx->DrawBuffer->_Xmin;
707 const GLint xmax = ctx->DrawBuffer->_Xmax;
708 const GLint ymin = ctx->DrawBuffer->_Ymin;
709 const GLint ymax = ctx->DrawBuffer->_Ymax;
710
711 span->leftClip = 0;
712
713 if (span->arrayMask & SPAN_XY) {
714 /* arrays of x/y pixel coords */
715 const GLint *x = span->array->x;
716 const GLint *y = span->array->y;
717 const GLint n = span->end;
718 GLubyte *mask = span->array->mask;
719 GLint i;
720 GLuint passed = 0;
721 if (span->arrayMask & SPAN_MASK) {
722 /* note: using & intead of && to reduce branches */
723 for (i = 0; i < n; i++) {
724 mask[i] &= (x[i] >= xmin) & (x[i] < xmax)
725 & (y[i] >= ymin) & (y[i] < ymax);
726 passed += mask[i];
727 }
728 }
729 else {
730 /* note: using & intead of && to reduce branches */
731 for (i = 0; i < n; i++) {
732 mask[i] = (x[i] >= xmin) & (x[i] < xmax)
733 & (y[i] >= ymin) & (y[i] < ymax);
734 passed += mask[i];
735 }
736 }
737 return passed > 0;
738 }
739 else {
740 /* horizontal span of pixels */
741 const GLint x = span->x;
742 const GLint y = span->y;
743 GLint n = span->end;
744
745 /* Trivial rejection tests */
746 if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {
747 span->end = 0;
748 return GL_FALSE; /* all pixels clipped */
749 }
750
751 /* Clip to right */
752 if (x + n > xmax) {
753 assert(x < xmax);
754 n = span->end = xmax - x;
755 }
756
757 /* Clip to the left */
758 if (x < xmin) {
759 const GLint leftClip = xmin - x;
760 GLuint i;
761
762 assert(leftClip > 0);
763 assert(x + n > xmin);
764
765 /* Clip 'leftClip' pixels from the left side.
766 * The span->leftClip field will be applied when we interpolate
767 * fragment attributes.
768 * For arrays of values, shift them left.
769 */
770 for (i = 0; i < VARYING_SLOT_MAX; i++) {
771 if (span->interpMask & (1 << i)) {
772 GLuint j;
773 for (j = 0; j < 4; j++) {
774 span->attrStart[i][j] += leftClip * span->attrStepX[i][j];
775 }
776 }
777 }
778
779 span->red += leftClip * span->redStep;
780 span->green += leftClip * span->greenStep;
781 span->blue += leftClip * span->blueStep;
782 span->alpha += leftClip * span->alphaStep;
783 span->index += leftClip * span->indexStep;
784 span->z += leftClip * span->zStep;
785 span->intTex[0] += leftClip * span->intTexStep[0];
786 span->intTex[1] += leftClip * span->intTexStep[1];
787
788 #define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
789 memmove(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
790
791 for (i = 0; i < VARYING_SLOT_MAX; i++) {
792 if (span->arrayAttribs & BITFIELD64_BIT(i)) {
793 /* shift array elements left by 'leftClip' */
794 SHIFT_ARRAY(span->array->attribs[i], leftClip, n - leftClip);
795 }
796 }
797
798 SHIFT_ARRAY(span->array->mask, leftClip, n - leftClip);
799 SHIFT_ARRAY(span->array->rgba8, leftClip, n - leftClip);
800 SHIFT_ARRAY(span->array->rgba16, leftClip, n - leftClip);
801 SHIFT_ARRAY(span->array->x, leftClip, n - leftClip);
802 SHIFT_ARRAY(span->array->y, leftClip, n - leftClip);
803 SHIFT_ARRAY(span->array->z, leftClip, n - leftClip);
804 SHIFT_ARRAY(span->array->index, leftClip, n - leftClip);
805 for (i = 0; i < MAX_TEXTURE_COORD_UNITS; i++) {
806 SHIFT_ARRAY(span->array->lambda[i], leftClip, n - leftClip);
807 }
808 SHIFT_ARRAY(span->array->coverage, leftClip, n - leftClip);
809
810 #undef SHIFT_ARRAY
811
812 span->leftClip = leftClip;
813 span->x = xmin;
814 span->end -= leftClip;
815 span->writeAll = GL_FALSE;
816 }
817
818 assert(span->x >= xmin);
819 assert(span->x + span->end <= xmax);
820 assert(span->y >= ymin);
821 assert(span->y < ymax);
822
823 return GL_TRUE; /* some pixels visible */
824 }
825 }
826
827
828 /**
829 * Add specular colors to primary colors.
830 * Only called during fixed-function operation.
831 * Result is float color array (VARYING_SLOT_COL0).
832 */
833 static inline void
add_specular(struct gl_context * ctx,SWspan * span)834 add_specular(struct gl_context *ctx, SWspan *span)
835 {
836 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
837 const GLubyte *mask = span->array->mask;
838 GLfloat (*col0)[4] = span->array->attribs[VARYING_SLOT_COL0];
839 GLfloat (*col1)[4] = span->array->attribs[VARYING_SLOT_COL1];
840 GLuint i;
841
842 assert(!_swrast_use_fragment_program(ctx));
843 assert(span->arrayMask & SPAN_RGBA);
844 assert(swrast->_ActiveAttribMask & VARYING_BIT_COL1);
845 (void) swrast; /* silence warning */
846
847 if (span->array->ChanType == GL_FLOAT) {
848 if ((span->arrayAttribs & VARYING_BIT_COL0) == 0) {
849 interpolate_active_attribs(ctx, span, VARYING_BIT_COL0);
850 }
851 }
852 else {
853 /* need float colors */
854 if ((span->arrayAttribs & VARYING_BIT_COL0) == 0) {
855 interpolate_float_colors(span);
856 }
857 }
858
859 if ((span->arrayAttribs & VARYING_BIT_COL1) == 0) {
860 /* XXX could avoid this and interpolate COL1 in the loop below */
861 interpolate_active_attribs(ctx, span, VARYING_BIT_COL1);
862 }
863
864 assert(span->arrayAttribs & VARYING_BIT_COL0);
865 assert(span->arrayAttribs & VARYING_BIT_COL1);
866
867 for (i = 0; i < span->end; i++) {
868 if (mask[i]) {
869 col0[i][0] += col1[i][0];
870 col0[i][1] += col1[i][1];
871 col0[i][2] += col1[i][2];
872 }
873 }
874
875 span->array->ChanType = GL_FLOAT;
876 }
877
878
879 /**
880 * Apply antialiasing coverage value to alpha values.
881 */
882 static inline void
apply_aa_coverage(SWspan * span)883 apply_aa_coverage(SWspan *span)
884 {
885 const GLfloat *coverage = span->array->coverage;
886 GLuint i;
887 if (span->array->ChanType == GL_UNSIGNED_BYTE) {
888 GLubyte (*rgba)[4] = span->array->rgba8;
889 for (i = 0; i < span->end; i++) {
890 const GLfloat a = rgba[i][ACOMP] * coverage[i];
891 rgba[i][ACOMP] = (GLubyte) CLAMP(a, 0.0F, 255.0F);
892 assert(coverage[i] >= 0.0F);
893 assert(coverage[i] <= 1.0F);
894 }
895 }
896 else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
897 GLushort (*rgba)[4] = span->array->rgba16;
898 for (i = 0; i < span->end; i++) {
899 const GLfloat a = rgba[i][ACOMP] * coverage[i];
900 rgba[i][ACOMP] = (GLushort) CLAMP(a, 0.0F, 65535.0F);
901 }
902 }
903 else {
904 GLfloat (*rgba)[4] = span->array->attribs[VARYING_SLOT_COL0];
905 for (i = 0; i < span->end; i++) {
906 rgba[i][ACOMP] = rgba[i][ACOMP] * coverage[i];
907 /* clamp later */
908 }
909 }
910 }
911
912
913 /**
914 * Clamp span's float colors to [0,1]
915 */
916 static inline void
clamp_colors(SWspan * span)917 clamp_colors(SWspan *span)
918 {
919 GLfloat (*rgba)[4] = span->array->attribs[VARYING_SLOT_COL0];
920 GLuint i;
921 assert(span->array->ChanType == GL_FLOAT);
922 for (i = 0; i < span->end; i++) {
923 rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
924 rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
925 rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
926 rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
927 }
928 }
929
930
931 /**
932 * Convert the span's color arrays to the given type.
933 * The only way 'output' can be greater than zero is when we have a fragment
934 * program that writes to gl_FragData[1] or higher.
935 * \param output which fragment program color output is being processed
936 */
937 static inline void
convert_color_type(SWspan * span,GLenum srcType,GLenum newType,GLuint output)938 convert_color_type(SWspan *span, GLenum srcType, GLenum newType, GLuint output)
939 {
940 GLvoid *src, *dst;
941
942 if (output > 0 || srcType == GL_FLOAT) {
943 src = span->array->attribs[VARYING_SLOT_COL0 + output];
944 span->array->ChanType = GL_FLOAT;
945 }
946 else if (srcType == GL_UNSIGNED_BYTE) {
947 src = span->array->rgba8;
948 }
949 else {
950 assert(srcType == GL_UNSIGNED_SHORT);
951 src = span->array->rgba16;
952 }
953
954 if (newType == GL_UNSIGNED_BYTE) {
955 dst = span->array->rgba8;
956 }
957 else if (newType == GL_UNSIGNED_SHORT) {
958 dst = span->array->rgba16;
959 }
960 else {
961 dst = span->array->attribs[VARYING_SLOT_COL0];
962 }
963
964 _mesa_convert_colors(span->array->ChanType, src,
965 newType, dst,
966 span->end, span->array->mask);
967
968 span->array->ChanType = newType;
969 span->array->rgba = dst;
970 }
971
972
973
974 /**
975 * Apply fragment shader, fragment program or normal texturing to span.
976 */
977 static inline void
shade_texture_span(struct gl_context * ctx,SWspan * span)978 shade_texture_span(struct gl_context *ctx, SWspan *span)
979 {
980 if (_swrast_use_fragment_program(ctx) ||
981 _mesa_ati_fragment_shader_enabled(ctx)) {
982 /* programmable shading */
983 if (span->primitive == GL_BITMAP && span->array->ChanType != GL_FLOAT) {
984 convert_color_type(span, span->array->ChanType, GL_FLOAT, 0);
985 }
986 else {
987 span->array->rgba = (void *) span->array->attribs[VARYING_SLOT_COL0];
988 }
989
990 if (span->primitive != GL_POINT ||
991 (span->interpMask & SPAN_RGBA) ||
992 ctx->Point.PointSprite) {
993 /* for single-pixel points, we populated the arrays already */
994 interpolate_active_attribs(ctx, span, ~0);
995 }
996 span->array->ChanType = GL_FLOAT;
997
998 if (!(span->arrayMask & SPAN_Z))
999 _swrast_span_interpolate_z (ctx, span);
1000
1001 #if 0
1002 if (inputsRead & VARYING_BIT_POS)
1003 #else
1004 /* XXX always interpolate wpos so that DDX/DDY work */
1005 #endif
1006 interpolate_wpos(ctx, span);
1007
1008 /* Run fragment program/shader now */
1009 if (_swrast_use_fragment_program(ctx)) {
1010 _swrast_exec_fragment_program(ctx, span);
1011 }
1012 else {
1013 assert(_mesa_ati_fragment_shader_enabled(ctx));
1014 _swrast_exec_fragment_shader(ctx, span);
1015 }
1016 }
1017 else if (ctx->Texture._EnabledCoordUnits) {
1018 /* conventional texturing */
1019
1020 #if CHAN_BITS == 32
1021 if ((span->arrayAttribs & VARYING_BIT_COL0) == 0) {
1022 interpolate_int_colors(ctx, span);
1023 }
1024 #else
1025 if (!(span->arrayMask & SPAN_RGBA))
1026 interpolate_int_colors(ctx, span);
1027 #endif
1028 if ((span->arrayAttribs & VARYING_BITS_TEX_ANY) == 0x0)
1029 interpolate_texcoords(ctx, span);
1030
1031 _swrast_texture_span(ctx, span);
1032 }
1033 }
1034
1035
1036 /** Put colors at x/y locations into a renderbuffer */
1037 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)1038 put_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1039 GLenum datatype,
1040 GLuint count, const GLint x[], const GLint y[],
1041 const void *values, const GLubyte *mask)
1042 {
1043 gl_pack_ubyte_rgba_func pack_ubyte = NULL;
1044 gl_pack_float_rgba_func pack_float = NULL;
1045 GLuint i;
1046
1047 if (datatype == GL_UNSIGNED_BYTE)
1048 pack_ubyte = _mesa_get_pack_ubyte_rgba_function(rb->Format);
1049 else
1050 pack_float = _mesa_get_pack_float_rgba_function(rb->Format);
1051
1052 for (i = 0; i < count; i++) {
1053 if (mask[i]) {
1054 GLubyte *dst = _swrast_pixel_address(rb, x[i], y[i]);
1055
1056 if (datatype == GL_UNSIGNED_BYTE) {
1057 pack_ubyte((const GLubyte *) values + 4 * i, dst);
1058 }
1059 else {
1060 assert(datatype == GL_FLOAT);
1061 pack_float((const GLfloat *) values + 4 * i, dst);
1062 }
1063 }
1064 }
1065 }
1066
1067
1068 /** Put row of colors into renderbuffer */
1069 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)1070 _swrast_put_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1071 GLenum datatype,
1072 GLuint count, GLint x, GLint y,
1073 const void *values, const GLubyte *mask)
1074 {
1075 GLubyte *dst = _swrast_pixel_address(rb, x, y);
1076
1077 if (!mask) {
1078 if (datatype == GL_UNSIGNED_BYTE) {
1079 _mesa_pack_ubyte_rgba_row(rb->Format, count,
1080 (const GLubyte (*)[4]) values, dst);
1081 }
1082 else {
1083 assert(datatype == GL_FLOAT);
1084 _mesa_pack_float_rgba_row(rb->Format, count,
1085 (const GLfloat (*)[4]) values, dst);
1086 }
1087 }
1088 else {
1089 const GLuint bpp = _mesa_get_format_bytes(rb->Format);
1090 GLuint i, runLen, runStart;
1091 /* We can't pass a 'mask' array to the _mesa_pack_rgba_row() functions
1092 * so look for runs where mask=1...
1093 */
1094 runLen = runStart = 0;
1095 for (i = 0; i < count; i++) {
1096 if (mask[i]) {
1097 if (runLen == 0)
1098 runStart = i;
1099 runLen++;
1100 }
1101
1102 if (!mask[i] || i == count - 1) {
1103 /* might be the end of a run of pixels */
1104 if (runLen > 0) {
1105 if (datatype == GL_UNSIGNED_BYTE) {
1106 _mesa_pack_ubyte_rgba_row(rb->Format, runLen,
1107 (const GLubyte (*)[4]) values + runStart,
1108 dst + runStart * bpp);
1109 }
1110 else {
1111 assert(datatype == GL_FLOAT);
1112 _mesa_pack_float_rgba_row(rb->Format, runLen,
1113 (const GLfloat (*)[4]) values + runStart,
1114 dst + runStart * bpp);
1115 }
1116 runLen = 0;
1117 }
1118 }
1119 }
1120 }
1121 }
1122
1123
1124
1125 /**
1126 * Apply all the per-fragment operations to a span.
1127 * This now includes texturing (_swrast_write_texture_span() is history).
1128 * This function may modify any of the array values in the span.
1129 * span->interpMask and span->arrayMask may be changed but will be restored
1130 * to their original values before returning.
1131 */
1132 void
_swrast_write_rgba_span(struct gl_context * ctx,SWspan * span)1133 _swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)
1134 {
1135 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
1136 const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;
1137 const GLbitfield origInterpMask = span->interpMask;
1138 const GLbitfield origArrayMask = span->arrayMask;
1139 const GLbitfield64 origArrayAttribs = span->arrayAttribs;
1140 const GLenum origChanType = span->array->ChanType;
1141 void * const origRgba = span->array->rgba;
1142 const GLboolean shader = (_swrast_use_fragment_program(ctx)
1143 || _mesa_ati_fragment_shader_enabled(ctx));
1144 const GLboolean shaderOrTexture = shader || ctx->Texture._EnabledCoordUnits;
1145 struct gl_framebuffer *fb = ctx->DrawBuffer;
1146
1147 /*
1148 printf("%s() interp 0x%x array 0x%x\n", __func__,
1149 span->interpMask, span->arrayMask);
1150 */
1151
1152 assert(span->primitive == GL_POINT ||
1153 span->primitive == GL_LINE ||
1154 span->primitive == GL_POLYGON ||
1155 span->primitive == GL_BITMAP);
1156
1157 /* Fragment write masks */
1158 if (span->arrayMask & SPAN_MASK) {
1159 /* mask was initialized by caller, probably glBitmap */
1160 span->writeAll = GL_FALSE;
1161 }
1162 else {
1163 memset(span->array->mask, 1, span->end);
1164 span->writeAll = GL_TRUE;
1165 }
1166
1167 /* Clip to window/scissor box */
1168 if (!clip_span(ctx, span)) {
1169 return;
1170 }
1171
1172 assert(span->end <= SWRAST_MAX_WIDTH);
1173
1174 /* Depth bounds test */
1175 if (ctx->Depth.BoundsTest && fb->Visual.depthBits > 0) {
1176 if (!_swrast_depth_bounds_test(ctx, span)) {
1177 return;
1178 }
1179 }
1180
1181 #ifdef DEBUG
1182 /* Make sure all fragments are within window bounds */
1183 if (span->arrayMask & SPAN_XY) {
1184 /* array of pixel locations */
1185 GLuint i;
1186 for (i = 0; i < span->end; i++) {
1187 if (span->array->mask[i]) {
1188 assert(span->array->x[i] >= fb->_Xmin);
1189 assert(span->array->x[i] < fb->_Xmax);
1190 assert(span->array->y[i] >= fb->_Ymin);
1191 assert(span->array->y[i] < fb->_Ymax);
1192 }
1193 }
1194 }
1195 #endif
1196
1197 /* Polygon Stippling */
1198 if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
1199 stipple_polygon_span(ctx, span);
1200 }
1201
1202 /* This is the normal place to compute the fragment color/Z
1203 * from texturing or shading.
1204 */
1205 if (shaderOrTexture && !swrast->_DeferredTexture) {
1206 shade_texture_span(ctx, span);
1207 }
1208
1209 /* Do the alpha test */
1210 if (ctx->Color.AlphaEnabled) {
1211 if (!_swrast_alpha_test(ctx, span)) {
1212 /* all fragments failed test */
1213 goto end;
1214 }
1215 }
1216
1217 /* Stencil and Z testing */
1218 if (_mesa_stencil_is_enabled(ctx) || ctx->Depth.Test) {
1219 if (!(span->arrayMask & SPAN_Z))
1220 _swrast_span_interpolate_z(ctx, span);
1221
1222 if (ctx->Transform.DepthClamp)
1223 _swrast_depth_clamp_span(ctx, span);
1224
1225 if (_mesa_stencil_is_enabled(ctx)) {
1226 /* Combined Z/stencil tests */
1227 if (!_swrast_stencil_and_ztest_span(ctx, span)) {
1228 /* all fragments failed test */
1229 goto end;
1230 }
1231 }
1232 else if (fb->Visual.depthBits > 0) {
1233 /* Just regular depth testing */
1234 assert(ctx->Depth.Test);
1235 assert(span->arrayMask & SPAN_Z);
1236 if (!_swrast_depth_test_span(ctx, span)) {
1237 /* all fragments failed test */
1238 goto end;
1239 }
1240 }
1241 }
1242
1243 if (ctx->Query.CurrentOcclusionObject) {
1244 /* update count of 'passed' fragments */
1245 struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
1246 GLuint i;
1247 for (i = 0; i < span->end; i++)
1248 q->Result += span->array->mask[i];
1249 }
1250
1251 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1252 * the occlusion test.
1253 */
1254 if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {
1255 /* no colors to write */
1256 goto end;
1257 }
1258
1259 /* If we were able to defer fragment color computation to now, there's
1260 * a good chance that many fragments will have already been killed by
1261 * Z/stencil testing.
1262 */
1263 if (shaderOrTexture && swrast->_DeferredTexture) {
1264 shade_texture_span(ctx, span);
1265 }
1266
1267 #if CHAN_BITS == 32
1268 if ((span->arrayAttribs & VARYING_BIT_COL0) == 0) {
1269 interpolate_active_attribs(ctx, span, VARYING_BIT_COL0);
1270 }
1271 #else
1272 if ((span->arrayMask & SPAN_RGBA) == 0) {
1273 interpolate_int_colors(ctx, span);
1274 }
1275 #endif
1276
1277 assert(span->arrayMask & SPAN_RGBA);
1278
1279 if (span->primitive == GL_BITMAP || !swrast->SpecularVertexAdd) {
1280 /* Add primary and specular (diffuse + specular) colors */
1281 if (!shader) {
1282 if (ctx->Fog.ColorSumEnabled ||
1283 (ctx->Light.Enabled &&
1284 ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {
1285 add_specular(ctx, span);
1286 }
1287 }
1288 }
1289
1290 /* Fog */
1291 if (swrast->_FogEnabled) {
1292 _swrast_fog_rgba_span(ctx, span);
1293 }
1294
1295 /* Antialias coverage application */
1296 if (span->arrayMask & SPAN_COVERAGE) {
1297 apply_aa_coverage(span);
1298 }
1299
1300 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1301 if (ctx->Color.ClampFragmentColor == GL_TRUE &&
1302 span->array->ChanType == GL_FLOAT) {
1303 clamp_colors(span);
1304 }
1305
1306 /*
1307 * Write to renderbuffers.
1308 * Depending on glDrawBuffer() state and the which color outputs are
1309 * written by the fragment shader, we may either replicate one color to
1310 * all renderbuffers or write a different color to each renderbuffer.
1311 * multiFragOutputs=TRUE for the later case.
1312 */
1313 {
1314 const GLuint numBuffers = fb->_NumColorDrawBuffers;
1315 const struct gl_program *fp = ctx->FragmentProgram._Current;
1316 const GLboolean multiFragOutputs =
1317 _swrast_use_fragment_program(ctx)
1318 && fp->info.outputs_written >= (1 << FRAG_RESULT_DATA0);
1319 /* Save srcColorType because convert_color_type() can change it */
1320 const GLenum srcColorType = span->array->ChanType;
1321 GLuint buf;
1322
1323 for (buf = 0; buf < numBuffers; buf++) {
1324 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];
1325
1326 /* color[fragOutput] will be written to buffer[buf] */
1327
1328 if (rb) {
1329 /* re-use one of the attribute array buffers for rgbaSave */
1330 GLchan (*rgbaSave)[4] = (GLchan (*)[4]) span->array->attribs[0];
1331 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
1332 const GLenum dstColorType = srb->ColorType;
1333
1334 assert(dstColorType == GL_UNSIGNED_BYTE ||
1335 dstColorType == GL_FLOAT);
1336
1337 /* set span->array->rgba to colors for renderbuffer's datatype */
1338 if (srcColorType != dstColorType) {
1339 convert_color_type(span, srcColorType, dstColorType,
1340 multiFragOutputs ? buf : 0);
1341 }
1342 else {
1343 if (srcColorType == GL_UNSIGNED_BYTE) {
1344 span->array->rgba = span->array->rgba8;
1345 }
1346 else {
1347 span->array->rgba = (void *)
1348 span->array->attribs[VARYING_SLOT_COL0];
1349 }
1350 }
1351
1352 if (!multiFragOutputs && numBuffers > 1) {
1353 /* save colors for second, third renderbuffer writes */
1354 memcpy(rgbaSave, span->array->rgba,
1355 4 * span->end * sizeof(GLchan));
1356 }
1357
1358 assert(rb->_BaseFormat == GL_RGBA ||
1359 rb->_BaseFormat == GL_RGB ||
1360 rb->_BaseFormat == GL_RED ||
1361 rb->_BaseFormat == GL_RG ||
1362 rb->_BaseFormat == GL_ALPHA);
1363
1364 if (ctx->Color.ColorLogicOpEnabled) {
1365 _swrast_logicop_rgba_span(ctx, rb, span);
1366 }
1367 else if ((ctx->Color.BlendEnabled >> buf) & 1) {
1368 _swrast_blend_span(ctx, rb, span);
1369 }
1370
1371 if (colorMask[buf] != 0xffffffff) {
1372 _swrast_mask_rgba_span(ctx, rb, span, buf);
1373 }
1374
1375 if (span->arrayMask & SPAN_XY) {
1376 /* array of pixel coords */
1377 put_values(ctx, rb,
1378 span->array->ChanType, span->end,
1379 span->array->x, span->array->y,
1380 span->array->rgba, span->array->mask);
1381 }
1382 else {
1383 /* horizontal run of pixels */
1384 _swrast_put_row(ctx, rb,
1385 span->array->ChanType,
1386 span->end, span->x, span->y,
1387 span->array->rgba,
1388 span->writeAll ? NULL: span->array->mask);
1389 }
1390
1391 if (!multiFragOutputs && numBuffers > 1) {
1392 /* restore original span values */
1393 memcpy(span->array->rgba, rgbaSave,
1394 4 * span->end * sizeof(GLchan));
1395 }
1396
1397 } /* if rb */
1398 } /* for buf */
1399 }
1400
1401 end:
1402 /* restore these values before returning */
1403 span->interpMask = origInterpMask;
1404 span->arrayMask = origArrayMask;
1405 span->arrayAttribs = origArrayAttribs;
1406 span->array->ChanType = origChanType;
1407 span->array->rgba = origRgba;
1408 }
1409
1410
1411 /**
1412 * Read float RGBA pixels from a renderbuffer. Clipping will be done to
1413 * prevent reading ouside the buffer's boundaries.
1414 * \param rgba the returned colors
1415 */
1416 void
_swrast_read_rgba_span(struct gl_context * ctx,struct gl_renderbuffer * rb,GLuint n,GLint x,GLint y,GLvoid * rgba)1417 _swrast_read_rgba_span( struct gl_context *ctx, struct gl_renderbuffer *rb,
1418 GLuint n, GLint x, GLint y,
1419 GLvoid *rgba)
1420 {
1421 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
1422 GLenum dstType = GL_FLOAT;
1423 const GLint bufWidth = (GLint) rb->Width;
1424 const GLint bufHeight = (GLint) rb->Height;
1425
1426 if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
1427 /* completely above, below, or right */
1428 /* XXX maybe leave rgba values undefined? */
1429 memset(rgba, 0, 4 * n * sizeof(GLchan));
1430 }
1431 else {
1432 GLint skip, length;
1433 GLubyte *src;
1434
1435 if (x < 0) {
1436 /* left edge clipping */
1437 skip = -x;
1438 length = (GLint) n - skip;
1439 if (length < 0) {
1440 /* completely left of window */
1441 return;
1442 }
1443 if (length > bufWidth) {
1444 length = bufWidth;
1445 }
1446 }
1447 else if ((GLint) (x + n) > bufWidth) {
1448 /* right edge clipping */
1449 skip = 0;
1450 length = bufWidth - x;
1451 if (length < 0) {
1452 /* completely to right of window */
1453 return;
1454 }
1455 }
1456 else {
1457 /* no clipping */
1458 skip = 0;
1459 length = (GLint) n;
1460 }
1461
1462 assert(rb);
1463 assert(rb->_BaseFormat == GL_RGBA ||
1464 rb->_BaseFormat == GL_RGB ||
1465 rb->_BaseFormat == GL_RG ||
1466 rb->_BaseFormat == GL_RED ||
1467 rb->_BaseFormat == GL_LUMINANCE ||
1468 rb->_BaseFormat == GL_INTENSITY ||
1469 rb->_BaseFormat == GL_LUMINANCE_ALPHA ||
1470 rb->_BaseFormat == GL_ALPHA);
1471
1472 assert(srb->Map);
1473 (void) srb; /* silence unused var warning */
1474
1475 src = _swrast_pixel_address(rb, x + skip, y);
1476
1477 if (dstType == GL_UNSIGNED_BYTE) {
1478 _mesa_unpack_ubyte_rgba_row(rb->Format, length, src,
1479 (GLubyte (*)[4]) rgba + skip);
1480 }
1481 else if (dstType == GL_FLOAT) {
1482 _mesa_unpack_rgba_row(rb->Format, length, src,
1483 (GLfloat (*)[4]) rgba + skip);
1484 }
1485 else {
1486 _mesa_problem(ctx, "unexpected type in _swrast_read_rgba_span()");
1487 }
1488 }
1489 }
1490
1491
1492 /**
1493 * Get colors at x/y positions with clipping.
1494 * \param type type of values to return
1495 */
1496 static void
get_values(struct gl_context * ctx,struct gl_renderbuffer * rb,GLuint count,const GLint x[],const GLint y[],void * values,GLenum type)1497 get_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1498 GLuint count, const GLint x[], const GLint y[],
1499 void *values, GLenum type)
1500 {
1501 GLuint i;
1502
1503 for (i = 0; i < count; i++) {
1504 if (x[i] >= 0 && y[i] >= 0 &&
1505 x[i] < (GLint) rb->Width && y[i] < (GLint) rb->Height) {
1506 /* inside */
1507 const GLubyte *src = _swrast_pixel_address(rb, x[i], y[i]);
1508
1509 if (type == GL_UNSIGNED_BYTE) {
1510 _mesa_unpack_ubyte_rgba_row(rb->Format, 1, src,
1511 (GLubyte (*)[4]) values + i);
1512 }
1513 else if (type == GL_FLOAT) {
1514 _mesa_unpack_rgba_row(rb->Format, 1, src,
1515 (GLfloat (*)[4]) values + i);
1516 }
1517 else {
1518 _mesa_problem(ctx, "unexpected type in get_values()");
1519 }
1520 }
1521 }
1522 }
1523
1524
1525 /**
1526 * Get row of colors with clipping.
1527 * \param type type of values to return
1528 */
1529 static void
get_row(struct gl_context * ctx,struct gl_renderbuffer * rb,GLuint count,GLint x,GLint y,GLvoid * values,GLenum type)1530 get_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1531 GLuint count, GLint x, GLint y,
1532 GLvoid *values, GLenum type)
1533 {
1534 GLint skip = 0;
1535 GLubyte *src;
1536
1537 if (y < 0 || y >= (GLint) rb->Height)
1538 return; /* above or below */
1539
1540 if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
1541 return; /* entirely left or right */
1542
1543 if (x + count > rb->Width) {
1544 /* right clip */
1545 GLint clip = x + count - rb->Width;
1546 count -= clip;
1547 }
1548
1549 if (x < 0) {
1550 /* left clip */
1551 skip = -x;
1552 x = 0;
1553 count -= skip;
1554 }
1555
1556 src = _swrast_pixel_address(rb, x, y);
1557
1558 if (type == GL_UNSIGNED_BYTE) {
1559 _mesa_unpack_ubyte_rgba_row(rb->Format, count, src,
1560 (GLubyte (*)[4]) values + skip);
1561 }
1562 else if (type == GL_FLOAT) {
1563 _mesa_unpack_rgba_row(rb->Format, count, src,
1564 (GLfloat (*)[4]) values + skip);
1565 }
1566 else {
1567 _mesa_problem(ctx, "unexpected type in get_row()");
1568 }
1569 }
1570
1571
1572 /**
1573 * Get RGBA pixels from the given renderbuffer.
1574 * Used by blending, logicop and masking functions.
1575 * \return pointer to the colors we read.
1576 */
1577 void *
_swrast_get_dest_rgba(struct gl_context * ctx,struct gl_renderbuffer * rb,SWspan * span)1578 _swrast_get_dest_rgba(struct gl_context *ctx, struct gl_renderbuffer *rb,
1579 SWspan *span)
1580 {
1581 void *rbPixels;
1582
1583 /* Point rbPixels to a temporary space */
1584 rbPixels = span->array->attribs[VARYING_SLOT_MAX - 1];
1585
1586 /* Get destination values from renderbuffer */
1587 if (span->arrayMask & SPAN_XY) {
1588 get_values(ctx, rb, span->end, span->array->x, span->array->y,
1589 rbPixels, span->array->ChanType);
1590 }
1591 else {
1592 get_row(ctx, rb, span->end, span->x, span->y,
1593 rbPixels, span->array->ChanType);
1594 }
1595
1596 return rbPixels;
1597 }
1598