2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
6 * Copyright (C) 2009 VMware, Inc. All Rights Reserved.
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:
15 * The above copyright notice and this permission notice shall be included
16 * in all copies or substantial portions of the Software.
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.
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
34 #include "main/glheader.h"
35 #include "main/colormac.h"
36 #include "main/macros.h"
37 #include "main/imports.h"
38 #include "main/image.h"
40 #include "s_atifragshader.h"
43 #include "s_context.h"
47 #include "s_masking.h"
48 #include "s_fragprog.h"
50 #include "s_stencil.h"
51 #include "s_texcombine.h"
56 * Set default fragment attributes for the span using the
57 * current raster values. Used prior to glDraw/CopyPixels
61 _swrast_span_default_attribs(struct gl_context *ctx, SWspan *span)
66 const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;
67 if (ctx->DrawBuffer->Visual.depthBits <= 16)
68 span->z = FloatToFixed(ctx->Current.RasterPos[2] * depthMax + 0.5F);
70 GLfloat tmpf = ctx->Current.RasterPos[2] * depthMax;
71 tmpf = MIN2(tmpf, depthMax);
72 span->z = (GLint)tmpf;
75 span->interpMask |= SPAN_Z;
78 /* W (for perspective correction) */
79 span->attrStart[FRAG_ATTRIB_WPOS][3] = 1.0;
80 span->attrStepX[FRAG_ATTRIB_WPOS][3] = 0.0;
81 span->attrStepY[FRAG_ATTRIB_WPOS][3] = 0.0;
83 /* primary color, or color index */
84 UNCLAMPED_FLOAT_TO_CHAN(r, ctx->Current.RasterColor[0]);
85 UNCLAMPED_FLOAT_TO_CHAN(g, ctx->Current.RasterColor[1]);
86 UNCLAMPED_FLOAT_TO_CHAN(b, ctx->Current.RasterColor[2]);
87 UNCLAMPED_FLOAT_TO_CHAN(a, ctx->Current.RasterColor[3]);
88 #if CHAN_TYPE == GL_FLOAT
94 span->red = IntToFixed(r);
95 span->green = IntToFixed(g);
96 span->blue = IntToFixed(b);
97 span->alpha = IntToFixed(a);
103 span->interpMask |= SPAN_RGBA;
105 COPY_4V(span->attrStart[FRAG_ATTRIB_COL0], ctx->Current.RasterColor);
106 ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
107 ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL0], 0.0, 0.0, 0.0, 0.0);
109 /* Secondary color */
110 if (ctx->Light.Enabled || ctx->Fog.ColorSumEnabled)
112 COPY_4V(span->attrStart[FRAG_ATTRIB_COL1], ctx->Current.RasterSecondaryColor);
113 ASSIGN_4V(span->attrStepX[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
114 ASSIGN_4V(span->attrStepY[FRAG_ATTRIB_COL1], 0.0, 0.0, 0.0, 0.0);
119 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
120 GLfloat fogVal; /* a coord or a blend factor */
121 if (swrast->_PreferPixelFog) {
122 /* fog blend factors will be computed from fog coordinates per pixel */
123 fogVal = ctx->Current.RasterDistance;
126 /* fog blend factor should be computed from fogcoord now */
127 fogVal = _swrast_z_to_fogfactor(ctx, ctx->Current.RasterDistance);
129 span->attrStart[FRAG_ATTRIB_FOGC][0] = fogVal;
130 span->attrStepX[FRAG_ATTRIB_FOGC][0] = 0.0;
131 span->attrStepY[FRAG_ATTRIB_FOGC][0] = 0.0;
137 for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
138 const GLuint attr = FRAG_ATTRIB_TEX0 + i;
139 const GLfloat *tc = ctx->Current.RasterTexCoords[i];
140 if (ctx->FragmentProgram._Current || ctx->ATIFragmentShader._Enabled) {
141 COPY_4V(span->attrStart[attr], tc);
143 else if (tc[3] > 0.0F) {
144 /* use (s/q, t/q, r/q, 1) */
145 span->attrStart[attr][0] = tc[0] / tc[3];
146 span->attrStart[attr][1] = tc[1] / tc[3];
147 span->attrStart[attr][2] = tc[2] / tc[3];
148 span->attrStart[attr][3] = 1.0;
151 ASSIGN_4V(span->attrStart[attr], 0.0F, 0.0F, 0.0F, 1.0F);
153 ASSIGN_4V(span->attrStepX[attr], 0.0F, 0.0F, 0.0F, 0.0F);
154 ASSIGN_4V(span->attrStepY[attr], 0.0F, 0.0F, 0.0F, 0.0F);
161 * Interpolate the active attributes (and'd with attrMask) to
162 * fill in span->array->attribs[].
163 * Perspective correction will be done. The point/line/triangle function
164 * should have computed attrStart/Step values for FRAG_ATTRIB_WPOS[3]!
167 interpolate_active_attribs(struct gl_context *ctx, SWspan *span,
168 GLbitfield64 attrMask)
170 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
173 * Don't overwrite existing array values, such as colors that may have
174 * been produced by glDraw/CopyPixels.
176 attrMask &= ~span->arrayAttribs;
179 if (attrMask & BITFIELD64_BIT(attr)) {
180 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
181 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3];
182 const GLfloat dv0dx = span->attrStepX[attr][0];
183 const GLfloat dv1dx = span->attrStepX[attr][1];
184 const GLfloat dv2dx = span->attrStepX[attr][2];
185 const GLfloat dv3dx = span->attrStepX[attr][3];
186 GLfloat v0 = span->attrStart[attr][0] + span->leftClip * dv0dx;
187 GLfloat v1 = span->attrStart[attr][1] + span->leftClip * dv1dx;
188 GLfloat v2 = span->attrStart[attr][2] + span->leftClip * dv2dx;
189 GLfloat v3 = span->attrStart[attr][3] + span->leftClip * dv3dx;
191 for (k = 0; k < span->end; k++) {
192 const GLfloat invW = 1.0f / w;
193 span->array->attribs[attr][k][0] = v0 * invW;
194 span->array->attribs[attr][k][1] = v1 * invW;
195 span->array->attribs[attr][k][2] = v2 * invW;
196 span->array->attribs[attr][k][3] = v3 * invW;
203 ASSERT((span->arrayAttribs & BITFIELD64_BIT(attr)) == 0);
204 span->arrayAttribs |= BITFIELD64_BIT(attr);
211 * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
215 interpolate_int_colors(struct gl_context *ctx, SWspan *span)
218 const GLuint n = span->end;
221 ASSERT(!(span->arrayMask & SPAN_RGBA));
224 switch (span->array->ChanType) {
226 case GL_UNSIGNED_BYTE:
228 GLubyte (*rgba)[4] = span->array->rgba8;
229 if (span->interpMask & SPAN_FLAT) {
231 color[RCOMP] = FixedToInt(span->red);
232 color[GCOMP] = FixedToInt(span->green);
233 color[BCOMP] = FixedToInt(span->blue);
234 color[ACOMP] = FixedToInt(span->alpha);
235 for (i = 0; i < n; i++) {
236 COPY_4UBV(rgba[i], color);
240 GLfixed r = span->red;
241 GLfixed g = span->green;
242 GLfixed b = span->blue;
243 GLfixed a = span->alpha;
244 GLint dr = span->redStep;
245 GLint dg = span->greenStep;
246 GLint db = span->blueStep;
247 GLint da = span->alphaStep;
248 for (i = 0; i < n; i++) {
249 rgba[i][RCOMP] = FixedToChan(r);
250 rgba[i][GCOMP] = FixedToChan(g);
251 rgba[i][BCOMP] = FixedToChan(b);
252 rgba[i][ACOMP] = FixedToChan(a);
261 case GL_UNSIGNED_SHORT:
263 GLushort (*rgba)[4] = span->array->rgba16;
264 if (span->interpMask & SPAN_FLAT) {
266 color[RCOMP] = FixedToInt(span->red);
267 color[GCOMP] = FixedToInt(span->green);
268 color[BCOMP] = FixedToInt(span->blue);
269 color[ACOMP] = FixedToInt(span->alpha);
270 for (i = 0; i < n; i++) {
271 COPY_4V(rgba[i], color);
275 GLushort (*rgba)[4] = span->array->rgba16;
277 GLint dr, dg, db, da;
283 dg = span->greenStep;
285 da = span->alphaStep;
286 for (i = 0; i < n; i++) {
287 rgba[i][RCOMP] = FixedToChan(r);
288 rgba[i][GCOMP] = FixedToChan(g);
289 rgba[i][BCOMP] = FixedToChan(b);
290 rgba[i][ACOMP] = FixedToChan(a);
301 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
304 _mesa_problem(ctx, "bad datatype 0x%x in interpolate_int_colors",
305 span->array->ChanType);
307 span->arrayMask |= SPAN_RGBA;
312 * Populate the FRAG_ATTRIB_COL0 array.
315 interpolate_float_colors(SWspan *span)
317 GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
318 const GLuint n = span->end;
321 assert(!(span->arrayAttribs & FRAG_BIT_COL0));
323 if (span->arrayMask & SPAN_RGBA) {
324 /* convert array of int colors */
325 for (i = 0; i < n; i++) {
326 col0[i][0] = UBYTE_TO_FLOAT(span->array->rgba8[i][0]);
327 col0[i][1] = UBYTE_TO_FLOAT(span->array->rgba8[i][1]);
328 col0[i][2] = UBYTE_TO_FLOAT(span->array->rgba8[i][2]);
329 col0[i][3] = UBYTE_TO_FLOAT(span->array->rgba8[i][3]);
333 /* interpolate red/green/blue/alpha to get float colors */
334 ASSERT(span->interpMask & SPAN_RGBA);
335 if (span->interpMask & SPAN_FLAT) {
336 GLfloat r = FixedToFloat(span->red);
337 GLfloat g = FixedToFloat(span->green);
338 GLfloat b = FixedToFloat(span->blue);
339 GLfloat a = FixedToFloat(span->alpha);
340 for (i = 0; i < n; i++) {
341 ASSIGN_4V(col0[i], r, g, b, a);
345 GLfloat r = FixedToFloat(span->red);
346 GLfloat g = FixedToFloat(span->green);
347 GLfloat b = FixedToFloat(span->blue);
348 GLfloat a = FixedToFloat(span->alpha);
349 GLfloat dr = FixedToFloat(span->redStep);
350 GLfloat dg = FixedToFloat(span->greenStep);
351 GLfloat db = FixedToFloat(span->blueStep);
352 GLfloat da = FixedToFloat(span->alphaStep);
353 for (i = 0; i < n; i++) {
366 span->arrayAttribs |= FRAG_BIT_COL0;
367 span->array->ChanType = GL_FLOAT;
373 * Fill in the span.zArray array from the span->z, zStep values.
376 _swrast_span_interpolate_z( const struct gl_context *ctx, SWspan *span )
378 const GLuint n = span->end;
381 ASSERT(!(span->arrayMask & SPAN_Z));
383 if (ctx->DrawBuffer->Visual.depthBits <= 16) {
384 GLfixed zval = span->z;
385 GLuint *z = span->array->z;
386 for (i = 0; i < n; i++) {
387 z[i] = FixedToInt(zval);
392 /* Deep Z buffer, no fixed->int shift */
393 GLuint zval = span->z;
394 GLuint *z = span->array->z;
395 for (i = 0; i < n; i++) {
400 span->interpMask &= ~SPAN_Z;
401 span->arrayMask |= SPAN_Z;
406 * Compute mipmap LOD from partial derivatives.
407 * This the ideal solution, as given in the OpenGL spec.
410 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
411 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
412 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
414 GLfloat dudx = texW * ((s + dsdx) / (q + dqdx) - s * invQ);
415 GLfloat dvdx = texH * ((t + dtdx) / (q + dqdx) - t * invQ);
416 GLfloat dudy = texW * ((s + dsdy) / (q + dqdy) - s * invQ);
417 GLfloat dvdy = texH * ((t + dtdy) / (q + dqdy) - t * invQ);
418 GLfloat x = SQRTF(dudx * dudx + dvdx * dvdx);
419 GLfloat y = SQRTF(dudy * dudy + dvdy * dvdy);
420 GLfloat rho = MAX2(x, y);
421 GLfloat lambda = LOG2(rho);
427 * Compute mipmap LOD from partial derivatives.
428 * This is a faster approximation than above function.
432 _swrast_compute_lambda(GLfloat dsdx, GLfloat dsdy, GLfloat dtdx, GLfloat dtdy,
433 GLfloat dqdx, GLfloat dqdy, GLfloat texW, GLfloat texH,
434 GLfloat s, GLfloat t, GLfloat q, GLfloat invQ)
436 GLfloat dsdx2 = (s + dsdx) / (q + dqdx) - s * invQ;
437 GLfloat dtdx2 = (t + dtdx) / (q + dqdx) - t * invQ;
438 GLfloat dsdy2 = (s + dsdy) / (q + dqdy) - s * invQ;
439 GLfloat dtdy2 = (t + dtdy) / (q + dqdy) - t * invQ;
440 GLfloat maxU, maxV, rho, lambda;
441 dsdx2 = FABSF(dsdx2);
442 dsdy2 = FABSF(dsdy2);
443 dtdx2 = FABSF(dtdx2);
444 dtdy2 = FABSF(dtdy2);
445 maxU = MAX2(dsdx2, dsdy2) * texW;
446 maxV = MAX2(dtdx2, dtdy2) * texH;
447 rho = MAX2(maxU, maxV);
455 * Fill in the span.array->attrib[FRAG_ATTRIB_TEXn] arrays from the
456 * using the attrStart/Step values.
458 * This function only used during fixed-function fragment processing.
460 * Note: in the places where we divide by Q (or mult by invQ) we're
461 * really doing two things: perspective correction and texcoord
462 * projection. Remember, for texcoord (s,t,r,q) we need to index
463 * texels with (s/q, t/q, r/q).
466 interpolate_texcoords(struct gl_context *ctx, SWspan *span)
469 = (ctx->Texture._EnabledCoordUnits > 1) ? ctx->Const.MaxTextureUnits : 1;
472 /* XXX CoordUnits vs. ImageUnits */
473 for (u = 0; u < maxUnit; u++) {
474 if (ctx->Texture._EnabledCoordUnits & (1 << u)) {
475 const GLuint attr = FRAG_ATTRIB_TEX0 + u;
476 const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
478 GLboolean needLambda;
479 GLfloat (*texcoord)[4] = span->array->attribs[attr];
480 GLfloat *lambda = span->array->lambda[u];
481 const GLfloat dsdx = span->attrStepX[attr][0];
482 const GLfloat dsdy = span->attrStepY[attr][0];
483 const GLfloat dtdx = span->attrStepX[attr][1];
484 const GLfloat dtdy = span->attrStepY[attr][1];
485 const GLfloat drdx = span->attrStepX[attr][2];
486 const GLfloat dqdx = span->attrStepX[attr][3];
487 const GLfloat dqdy = span->attrStepY[attr][3];
488 GLfloat s = span->attrStart[attr][0] + span->leftClip * dsdx;
489 GLfloat t = span->attrStart[attr][1] + span->leftClip * dtdx;
490 GLfloat r = span->attrStart[attr][2] + span->leftClip * drdx;
491 GLfloat q = span->attrStart[attr][3] + span->leftClip * dqdx;
494 const struct gl_texture_image *img = obj->Image[0][obj->BaseLevel];
495 const struct swrast_texture_image *swImg =
496 swrast_texture_image_const(img);
498 needLambda = (obj->Sampler.MinFilter != obj->Sampler.MagFilter)
499 || ctx->FragmentProgram._Current;
500 /* LOD is calculated directly in the ansiotropic filter, we can
501 * skip the normal lambda function as the result is ignored.
503 if (obj->Sampler.MaxAnisotropy > 1.0 &&
504 obj->Sampler.MinFilter == GL_LINEAR_MIPMAP_LINEAR) {
505 needLambda = GL_FALSE;
507 texW = swImg->WidthScale;
508 texH = swImg->HeightScale;
511 /* using a fragment program */
514 needLambda = GL_FALSE;
519 if (ctx->FragmentProgram._Current
520 || ctx->ATIFragmentShader._Enabled) {
521 /* do perspective correction but don't divide s, t, r by q */
522 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
523 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
524 for (i = 0; i < span->end; i++) {
525 const GLfloat invW = 1.0F / w;
526 texcoord[i][0] = s * invW;
527 texcoord[i][1] = t * invW;
528 texcoord[i][2] = r * invW;
529 texcoord[i][3] = q * invW;
530 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
531 dqdx, dqdy, texW, texH,
541 for (i = 0; i < span->end; i++) {
542 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
543 texcoord[i][0] = s * invQ;
544 texcoord[i][1] = t * invQ;
545 texcoord[i][2] = r * invQ;
547 lambda[i] = _swrast_compute_lambda(dsdx, dsdy, dtdx, dtdy,
548 dqdx, dqdy, texW, texH,
556 span->arrayMask |= SPAN_LAMBDA;
560 if (ctx->FragmentProgram._Current ||
561 ctx->ATIFragmentShader._Enabled) {
562 /* do perspective correction but don't divide s, t, r by q */
563 const GLfloat dwdx = span->attrStepX[FRAG_ATTRIB_WPOS][3];
564 GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dwdx;
565 for (i = 0; i < span->end; i++) {
566 const GLfloat invW = 1.0F / w;
567 texcoord[i][0] = s * invW;
568 texcoord[i][1] = t * invW;
569 texcoord[i][2] = r * invW;
570 texcoord[i][3] = q * invW;
579 else if (dqdx == 0.0F) {
580 /* Ortho projection or polygon's parallel to window X axis */
581 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
582 for (i = 0; i < span->end; i++) {
583 texcoord[i][0] = s * invQ;
584 texcoord[i][1] = t * invQ;
585 texcoord[i][2] = r * invQ;
594 for (i = 0; i < span->end; i++) {
595 const GLfloat invQ = (q == 0.0F) ? 1.0F : (1.0F / q);
596 texcoord[i][0] = s * invQ;
597 texcoord[i][1] = t * invQ;
598 texcoord[i][2] = r * invQ;
614 * Fill in the arrays->attribs[FRAG_ATTRIB_WPOS] array.
617 interpolate_wpos(struct gl_context *ctx, SWspan *span)
619 GLfloat (*wpos)[4] = span->array->attribs[FRAG_ATTRIB_WPOS];
621 const GLfloat zScale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
624 if (span->arrayMask & SPAN_XY) {
625 for (i = 0; i < span->end; i++) {
626 wpos[i][0] = (GLfloat) span->array->x[i];
627 wpos[i][1] = (GLfloat) span->array->y[i];
631 for (i = 0; i < span->end; i++) {
632 wpos[i][0] = (GLfloat) span->x + i;
633 wpos[i][1] = (GLfloat) span->y;
637 dw = span->attrStepX[FRAG_ATTRIB_WPOS][3];
638 w = span->attrStart[FRAG_ATTRIB_WPOS][3] + span->leftClip * dw;
639 for (i = 0; i < span->end; i++) {
640 wpos[i][2] = (GLfloat) span->array->z[i] * zScale;
648 * Apply the current polygon stipple pattern to a span of pixels.
651 stipple_polygon_span(struct gl_context *ctx, SWspan *span)
653 GLubyte *mask = span->array->mask;
655 ASSERT(ctx->Polygon.StippleFlag);
657 if (span->arrayMask & SPAN_XY) {
658 /* arrays of x/y pixel coords */
660 for (i = 0; i < span->end; i++) {
661 const GLint col = span->array->x[i] % 32;
662 const GLint row = span->array->y[i] % 32;
663 const GLuint stipple = ctx->PolygonStipple[row];
664 if (((1 << col) & stipple) == 0) {
670 /* horizontal span of pixels */
671 const GLuint highBit = 1 << 31;
672 const GLuint stipple = ctx->PolygonStipple[span->y % 32];
673 GLuint i, m = highBit >> (GLuint) (span->x % 32);
674 for (i = 0; i < span->end; i++) {
675 if ((m & stipple) == 0) {
684 span->writeAll = GL_FALSE;
689 * Clip a pixel span to the current buffer/window boundaries:
690 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
691 * window clipping and scissoring.
692 * Return: GL_TRUE some pixels still visible
693 * GL_FALSE nothing visible
696 clip_span( struct gl_context *ctx, SWspan *span )
698 const GLint xmin = ctx->DrawBuffer->_Xmin;
699 const GLint xmax = ctx->DrawBuffer->_Xmax;
700 const GLint ymin = ctx->DrawBuffer->_Ymin;
701 const GLint ymax = ctx->DrawBuffer->_Ymax;
705 if (span->arrayMask & SPAN_XY) {
706 /* arrays of x/y pixel coords */
707 const GLint *x = span->array->x;
708 const GLint *y = span->array->y;
709 const GLint n = span->end;
710 GLubyte *mask = span->array->mask;
713 if (span->arrayMask & SPAN_MASK) {
714 /* note: using & intead of && to reduce branches */
715 for (i = 0; i < n; i++) {
716 mask[i] &= (x[i] >= xmin) & (x[i] < xmax)
717 & (y[i] >= ymin) & (y[i] < ymax);
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);
732 /* horizontal span of pixels */
733 const GLint x = span->x;
734 const GLint y = span->y;
737 /* Trivial rejection tests */
738 if (y < ymin || y >= ymax || x + n <= xmin || x >= xmax) {
740 return GL_FALSE; /* all pixels clipped */
746 n = span->end = xmax - x;
749 /* Clip to the left */
751 const GLint leftClip = xmin - x;
754 ASSERT(leftClip > 0);
755 ASSERT(x + n > xmin);
757 /* Clip 'leftClip' pixels from the left side.
758 * The span->leftClip field will be applied when we interpolate
759 * fragment attributes.
760 * For arrays of values, shift them left.
762 for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
763 if (span->interpMask & (1 << i)) {
765 for (j = 0; j < 4; j++) {
766 span->attrStart[i][j] += leftClip * span->attrStepX[i][j];
771 span->red += leftClip * span->redStep;
772 span->green += leftClip * span->greenStep;
773 span->blue += leftClip * span->blueStep;
774 span->alpha += leftClip * span->alphaStep;
775 span->index += leftClip * span->indexStep;
776 span->z += leftClip * span->zStep;
777 span->intTex[0] += leftClip * span->intTexStep[0];
778 span->intTex[1] += leftClip * span->intTexStep[1];
780 #define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
781 memmove(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
783 for (i = 0; i < FRAG_ATTRIB_MAX; i++) {
784 if (span->arrayAttribs & (1 << i)) {
785 /* shift array elements left by 'leftClip' */
786 SHIFT_ARRAY(span->array->attribs[i], leftClip, n - leftClip);
790 SHIFT_ARRAY(span->array->mask, leftClip, n - leftClip);
791 SHIFT_ARRAY(span->array->rgba8, leftClip, n - leftClip);
792 SHIFT_ARRAY(span->array->rgba16, leftClip, n - leftClip);
793 SHIFT_ARRAY(span->array->x, leftClip, n - leftClip);
794 SHIFT_ARRAY(span->array->y, leftClip, n - leftClip);
795 SHIFT_ARRAY(span->array->z, leftClip, n - leftClip);
796 SHIFT_ARRAY(span->array->index, leftClip, n - leftClip);
797 for (i = 0; i < MAX_TEXTURE_COORD_UNITS; i++) {
798 SHIFT_ARRAY(span->array->lambda[i], leftClip, n - leftClip);
800 SHIFT_ARRAY(span->array->coverage, leftClip, n - leftClip);
804 span->leftClip = leftClip;
806 span->end -= leftClip;
807 span->writeAll = GL_FALSE;
810 ASSERT(span->x >= xmin);
811 ASSERT(span->x + span->end <= xmax);
812 ASSERT(span->y >= ymin);
813 ASSERT(span->y < ymax);
815 return GL_TRUE; /* some pixels visible */
821 * Add specular colors to primary colors.
822 * Only called during fixed-function operation.
823 * Result is float color array (FRAG_ATTRIB_COL0).
826 add_specular(struct gl_context *ctx, SWspan *span)
828 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
829 const GLubyte *mask = span->array->mask;
830 GLfloat (*col0)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
831 GLfloat (*col1)[4] = span->array->attribs[FRAG_ATTRIB_COL1];
834 ASSERT(!ctx->FragmentProgram._Current);
835 ASSERT(span->arrayMask & SPAN_RGBA);
836 ASSERT(swrast->_ActiveAttribMask & FRAG_BIT_COL1);
837 (void) swrast; /* silence warning */
839 if (span->array->ChanType == GL_FLOAT) {
840 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
841 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
845 /* need float colors */
846 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
847 interpolate_float_colors(span);
851 if ((span->arrayAttribs & FRAG_BIT_COL1) == 0) {
852 /* XXX could avoid this and interpolate COL1 in the loop below */
853 interpolate_active_attribs(ctx, span, FRAG_BIT_COL1);
856 ASSERT(span->arrayAttribs & FRAG_BIT_COL0);
857 ASSERT(span->arrayAttribs & FRAG_BIT_COL1);
859 for (i = 0; i < span->end; i++) {
861 col0[i][0] += col1[i][0];
862 col0[i][1] += col1[i][1];
863 col0[i][2] += col1[i][2];
867 span->array->ChanType = GL_FLOAT;
872 * Apply antialiasing coverage value to alpha values.
875 apply_aa_coverage(SWspan *span)
877 const GLfloat *coverage = span->array->coverage;
879 if (span->array->ChanType == GL_UNSIGNED_BYTE) {
880 GLubyte (*rgba)[4] = span->array->rgba8;
881 for (i = 0; i < span->end; i++) {
882 const GLfloat a = rgba[i][ACOMP] * coverage[i];
883 rgba[i][ACOMP] = (GLubyte) CLAMP(a, 0.0, 255.0);
884 ASSERT(coverage[i] >= 0.0);
885 ASSERT(coverage[i] <= 1.0);
888 else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
889 GLushort (*rgba)[4] = span->array->rgba16;
890 for (i = 0; i < span->end; i++) {
891 const GLfloat a = rgba[i][ACOMP] * coverage[i];
892 rgba[i][ACOMP] = (GLushort) CLAMP(a, 0.0, 65535.0);
896 GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
897 for (i = 0; i < span->end; i++) {
898 rgba[i][ACOMP] = rgba[i][ACOMP] * coverage[i];
906 * Clamp span's float colors to [0,1]
909 clamp_colors(SWspan *span)
911 GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
913 ASSERT(span->array->ChanType == GL_FLOAT);
914 for (i = 0; i < span->end; i++) {
915 rgba[i][RCOMP] = CLAMP(rgba[i][RCOMP], 0.0F, 1.0F);
916 rgba[i][GCOMP] = CLAMP(rgba[i][GCOMP], 0.0F, 1.0F);
917 rgba[i][BCOMP] = CLAMP(rgba[i][BCOMP], 0.0F, 1.0F);
918 rgba[i][ACOMP] = CLAMP(rgba[i][ACOMP], 0.0F, 1.0F);
924 * Convert the span's color arrays to the given type.
925 * The only way 'output' can be greater than zero is when we have a fragment
926 * program that writes to gl_FragData[1] or higher.
927 * \param output which fragment program color output is being processed
930 convert_color_type(SWspan *span, GLenum newType, GLuint output)
934 if (output > 0 || span->array->ChanType == GL_FLOAT) {
935 src = span->array->attribs[FRAG_ATTRIB_COL0 + output];
936 span->array->ChanType = GL_FLOAT;
938 else if (span->array->ChanType == GL_UNSIGNED_BYTE) {
939 src = span->array->rgba8;
942 ASSERT(span->array->ChanType == GL_UNSIGNED_SHORT);
943 src = span->array->rgba16;
946 if (newType == GL_UNSIGNED_BYTE) {
947 dst = span->array->rgba8;
949 else if (newType == GL_UNSIGNED_SHORT) {
950 dst = span->array->rgba16;
953 dst = span->array->attribs[FRAG_ATTRIB_COL0];
956 _mesa_convert_colors(span->array->ChanType, src,
958 span->end, span->array->mask);
960 span->array->ChanType = newType;
961 span->array->rgba = dst;
967 * Apply fragment shader, fragment program or normal texturing to span.
970 shade_texture_span(struct gl_context *ctx, SWspan *span)
972 /* This is a hack to work around drivers such as i965 that:
974 * - Set _MaintainTexEnvProgram to generate GLSL IR for
975 * fixed-function fragment processing.
976 * - Don't call _mesa_ir_link_shader to generate Mesa IR from
978 * - May use swrast to handle glDrawPixels.
980 * Since _mesa_ir_link_shader is never called, there is no Mesa IR
981 * to execute. Instead do regular fixed-function processing.
983 * It is also worth noting that the software fixed-function path is
984 * much faster than the software shader path.
986 const bool use_fragment_program =
987 ctx->FragmentProgram._Current
988 && ctx->FragmentProgram._Current != ctx->FragmentProgram._TexEnvProgram;
990 if (use_fragment_program ||
991 ctx->ATIFragmentShader._Enabled) {
992 /* programmable shading */
993 if (span->primitive == GL_BITMAP && span->array->ChanType != GL_FLOAT) {
994 convert_color_type(span, GL_FLOAT, 0);
997 span->array->rgba = (void *) span->array->attribs[FRAG_ATTRIB_COL0];
1000 if (span->primitive != GL_POINT ||
1001 (span->interpMask & SPAN_RGBA) ||
1002 ctx->Point.PointSprite) {
1003 /* for single-pixel points, we populated the arrays already */
1004 interpolate_active_attribs(ctx, span, ~0);
1006 span->array->ChanType = GL_FLOAT;
1008 if (!(span->arrayMask & SPAN_Z))
1009 _swrast_span_interpolate_z (ctx, span);
1012 if (inputsRead & FRAG_BIT_WPOS)
1014 /* XXX always interpolate wpos so that DDX/DDY work */
1016 interpolate_wpos(ctx, span);
1018 /* Run fragment program/shader now */
1019 if (use_fragment_program) {
1020 _swrast_exec_fragment_program(ctx, span);
1023 ASSERT(ctx->ATIFragmentShader._Enabled);
1024 _swrast_exec_fragment_shader(ctx, span);
1027 else if (ctx->Texture._EnabledCoordUnits) {
1028 /* conventional texturing */
1031 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
1032 interpolate_int_colors(ctx, span);
1035 if (!(span->arrayMask & SPAN_RGBA))
1036 interpolate_int_colors(ctx, span);
1038 if ((span->arrayAttribs & FRAG_BITS_TEX_ANY) == 0x0)
1039 interpolate_texcoords(ctx, span);
1041 _swrast_texture_span(ctx, span);
1048 * Apply all the per-fragment operations to a span.
1049 * This now includes texturing (_swrast_write_texture_span() is history).
1050 * This function may modify any of the array values in the span.
1051 * span->interpMask and span->arrayMask may be changed but will be restored
1052 * to their original values before returning.
1055 _swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)
1057 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
1058 const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;
1059 const GLbitfield origInterpMask = span->interpMask;
1060 const GLbitfield origArrayMask = span->arrayMask;
1061 const GLbitfield64 origArrayAttribs = span->arrayAttribs;
1062 const GLenum origChanType = span->array->ChanType;
1063 void * const origRgba = span->array->rgba;
1064 const GLboolean shader = (ctx->FragmentProgram._Current
1065 || ctx->ATIFragmentShader._Enabled);
1066 const GLboolean shaderOrTexture = shader || ctx->Texture._EnabledCoordUnits;
1067 struct gl_framebuffer *fb = ctx->DrawBuffer;
1070 printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__,
1071 span->interpMask, span->arrayMask);
1074 ASSERT(span->primitive == GL_POINT ||
1075 span->primitive == GL_LINE ||
1076 span->primitive == GL_POLYGON ||
1077 span->primitive == GL_BITMAP);
1079 /* Fragment write masks */
1080 if (span->arrayMask & SPAN_MASK) {
1081 /* mask was initialized by caller, probably glBitmap */
1082 span->writeAll = GL_FALSE;
1085 memset(span->array->mask, 1, span->end);
1086 span->writeAll = GL_TRUE;
1089 /* Clip to window/scissor box */
1090 if (!clip_span(ctx, span)) {
1094 ASSERT(span->end <= MAX_WIDTH);
1096 /* Depth bounds test */
1097 if (ctx->Depth.BoundsTest && fb->Visual.depthBits > 0) {
1098 if (!_swrast_depth_bounds_test(ctx, span)) {
1104 /* Make sure all fragments are within window bounds */
1105 if (span->arrayMask & SPAN_XY) {
1106 /* array of pixel locations */
1108 for (i = 0; i < span->end; i++) {
1109 if (span->array->mask[i]) {
1110 assert(span->array->x[i] >= fb->_Xmin);
1111 assert(span->array->x[i] < fb->_Xmax);
1112 assert(span->array->y[i] >= fb->_Ymin);
1113 assert(span->array->y[i] < fb->_Ymax);
1119 /* Polygon Stippling */
1120 if (ctx->Polygon.StippleFlag && span->primitive == GL_POLYGON) {
1121 stipple_polygon_span(ctx, span);
1124 /* This is the normal place to compute the fragment color/Z
1125 * from texturing or shading.
1127 if (shaderOrTexture && !swrast->_DeferredTexture) {
1128 shade_texture_span(ctx, span);
1131 /* Do the alpha test */
1132 if (ctx->Color.AlphaEnabled) {
1133 if (!_swrast_alpha_test(ctx, span)) {
1134 /* all fragments failed test */
1139 /* Stencil and Z testing */
1140 if (ctx->Stencil._Enabled || ctx->Depth.Test) {
1141 if (!(span->arrayMask & SPAN_Z))
1142 _swrast_span_interpolate_z(ctx, span);
1144 if (ctx->Transform.DepthClamp)
1145 _swrast_depth_clamp_span(ctx, span);
1147 if (ctx->Stencil._Enabled) {
1148 /* Combined Z/stencil tests */
1149 if (!_swrast_stencil_and_ztest_span(ctx, span)) {
1150 /* all fragments failed test */
1154 else if (fb->Visual.depthBits > 0) {
1155 /* Just regular depth testing */
1156 ASSERT(ctx->Depth.Test);
1157 ASSERT(span->arrayMask & SPAN_Z);
1158 if (!_swrast_depth_test_span(ctx, span)) {
1159 /* all fragments failed test */
1165 if (ctx->Query.CurrentOcclusionObject) {
1166 /* update count of 'passed' fragments */
1167 struct gl_query_object *q = ctx->Query.CurrentOcclusionObject;
1169 for (i = 0; i < span->end; i++)
1170 q->Result += span->array->mask[i];
1173 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1174 * the occlusion test.
1176 if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {
1177 /* no colors to write */
1181 /* If we were able to defer fragment color computation to now, there's
1182 * a good chance that many fragments will have already been killed by
1183 * Z/stencil testing.
1185 if (shaderOrTexture && swrast->_DeferredTexture) {
1186 shade_texture_span(ctx, span);
1190 if ((span->arrayAttribs & FRAG_BIT_COL0) == 0) {
1191 interpolate_active_attribs(ctx, span, FRAG_BIT_COL0);
1194 if ((span->arrayMask & SPAN_RGBA) == 0) {
1195 interpolate_int_colors(ctx, span);
1199 ASSERT(span->arrayMask & SPAN_RGBA);
1201 if (span->primitive == GL_BITMAP || !swrast->SpecularVertexAdd) {
1202 /* Add primary and specular (diffuse + specular) colors */
1204 if (ctx->Fog.ColorSumEnabled ||
1205 (ctx->Light.Enabled &&
1206 ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR)) {
1207 add_specular(ctx, span);
1213 if (swrast->_FogEnabled) {
1214 _swrast_fog_rgba_span(ctx, span);
1217 /* Antialias coverage application */
1218 if (span->arrayMask & SPAN_COVERAGE) {
1219 apply_aa_coverage(span);
1222 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1223 if (ctx->Color.ClampFragmentColor == GL_TRUE &&
1224 span->array->ChanType == GL_FLOAT) {
1229 * Write to renderbuffers.
1230 * Depending on glDrawBuffer() state and the which color outputs are
1231 * written by the fragment shader, we may either replicate one color to
1232 * all renderbuffers or write a different color to each renderbuffer.
1233 * multiFragOutputs=TRUE for the later case.
1236 const GLuint numBuffers = fb->_NumColorDrawBuffers;
1237 const struct gl_fragment_program *fp = ctx->FragmentProgram._Current;
1238 const GLboolean multiFragOutputs =
1239 (fp && fp->Base.OutputsWritten >= (1 << FRAG_RESULT_DATA0));
1242 for (buf = 0; buf < numBuffers; buf++) {
1243 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];
1245 /* color[fragOutput] will be written to buffer[buf] */
1248 GLchan rgbaSave[MAX_WIDTH][4];
1249 const GLuint fragOutput = multiFragOutputs ? buf : 0;
1251 /* set span->array->rgba to colors for render buffer's datatype */
1252 if (rb->DataType != span->array->ChanType || fragOutput > 0) {
1253 convert_color_type(span, rb->DataType, fragOutput);
1256 if (rb->DataType == GL_UNSIGNED_BYTE) {
1257 span->array->rgba = span->array->rgba8;
1259 else if (rb->DataType == GL_UNSIGNED_SHORT) {
1260 span->array->rgba = (void *) span->array->rgba16;
1263 span->array->rgba = (void *)
1264 span->array->attribs[FRAG_ATTRIB_COL0];
1268 if (!multiFragOutputs && numBuffers > 1) {
1269 /* save colors for second, third renderbuffer writes */
1270 memcpy(rgbaSave, span->array->rgba,
1271 4 * span->end * sizeof(GLchan));
1274 ASSERT(rb->_BaseFormat == GL_RGBA ||
1275 rb->_BaseFormat == GL_RGB ||
1276 rb->_BaseFormat == GL_RED ||
1277 rb->_BaseFormat == GL_RG ||
1278 rb->_BaseFormat == GL_ALPHA);
1280 if (ctx->Color.ColorLogicOpEnabled) {
1281 _swrast_logicop_rgba_span(ctx, rb, span);
1283 else if ((ctx->Color.BlendEnabled >> buf) & 1) {
1284 _swrast_blend_span(ctx, rb, span);
1287 if (colorMask[buf] != 0xffffffff) {
1288 _swrast_mask_rgba_span(ctx, rb, span, buf);
1291 if (span->arrayMask & SPAN_XY) {
1292 /* array of pixel coords */
1293 ASSERT(rb->PutValues);
1294 rb->PutValues(ctx, rb, span->end,
1295 span->array->x, span->array->y,
1296 span->array->rgba, span->array->mask);
1299 /* horizontal run of pixels */
1301 rb->PutRow(ctx, rb, span->end, span->x, span->y,
1303 span->writeAll ? NULL: span->array->mask);
1306 if (!multiFragOutputs && numBuffers > 1) {
1307 /* restore original span values */
1308 memcpy(span->array->rgba, rgbaSave,
1309 4 * span->end * sizeof(GLchan));
1317 /* restore these values before returning */
1318 span->interpMask = origInterpMask;
1319 span->arrayMask = origArrayMask;
1320 span->arrayAttribs = origArrayAttribs;
1321 span->array->ChanType = origChanType;
1322 span->array->rgba = origRgba;
1327 * Read RGBA pixels from a renderbuffer. Clipping will be done to prevent
1328 * reading ouside the buffer's boundaries.
1329 * \param dstType datatype for returned colors
1330 * \param rgba the returned colors
1333 _swrast_read_rgba_span( struct gl_context *ctx, struct gl_renderbuffer *rb,
1334 GLuint n, GLint x, GLint y, GLenum dstType,
1337 const GLint bufWidth = (GLint) rb->Width;
1338 const GLint bufHeight = (GLint) rb->Height;
1340 if (y < 0 || y >= bufHeight || x + (GLint) n < 0 || x >= bufWidth) {
1341 /* completely above, below, or right */
1342 /* XXX maybe leave rgba values undefined? */
1343 memset(rgba, 0, 4 * n * sizeof(GLchan));
1348 /* left edge clipping */
1350 length = (GLint) n - skip;
1352 /* completely left of window */
1355 if (length > bufWidth) {
1359 else if ((GLint) (x + n) > bufWidth) {
1360 /* right edge clipping */
1362 length = bufWidth - x;
1364 /* completely to right of window */
1376 ASSERT(rb->_BaseFormat == GL_RGBA ||
1377 rb->_BaseFormat == GL_RGB ||
1378 rb->_BaseFormat == GL_RG ||
1379 rb->_BaseFormat == GL_RED ||
1380 rb->_BaseFormat == GL_LUMINANCE ||
1381 rb->_BaseFormat == GL_INTENSITY ||
1382 rb->_BaseFormat == GL_LUMINANCE_ALPHA ||
1383 rb->_BaseFormat == GL_ALPHA);
1385 if (rb->DataType == dstType) {
1386 rb->GetRow(ctx, rb, length, x + skip, y,
1387 (GLubyte *) rgba + skip * RGBA_PIXEL_SIZE(rb->DataType));
1390 GLuint temp[MAX_WIDTH * 4];
1391 rb->GetRow(ctx, rb, length, x + skip, y, temp);
1392 _mesa_convert_colors(rb->DataType, temp,
1393 dstType, (GLubyte *) rgba + skip * RGBA_PIXEL_SIZE(dstType),
1401 * Wrapper for gl_renderbuffer::GetValues() which does clipping to avoid
1402 * reading values outside the buffer bounds.
1403 * We can use this for reading any format/type of renderbuffer.
1404 * \param valueSize is the size in bytes of each value (pixel) put into the
1408 _swrast_get_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
1409 GLuint count, const GLint x[], const GLint y[],
1410 void *values, GLuint valueSize)
1412 GLuint i, inCount = 0, inStart = 0;
1414 for (i = 0; i < count; i++) {
1415 if (x[i] >= 0 && y[i] >= 0 &&
1416 x[i] < (GLint) rb->Width && y[i] < (GLint) rb->Height) {
1424 /* read [inStart, inStart + inCount) */
1425 rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,
1426 (GLubyte *) values + inStart * valueSize);
1432 /* read last values */
1433 rb->GetValues(ctx, rb, inCount, x + inStart, y + inStart,
1434 (GLubyte *) values + inStart * valueSize);
1440 * Wrapper for gl_renderbuffer::PutRow() which does clipping.
1441 * \param valueSize size of each value (pixel) in bytes
1444 _swrast_put_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1445 GLuint count, GLint x, GLint y,
1446 const GLvoid *values, GLuint valueSize)
1450 if (y < 0 || y >= (GLint) rb->Height)
1451 return; /* above or below */
1453 if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
1454 return; /* entirely left or right */
1456 if ((GLint) (x + count) > (GLint) rb->Width) {
1458 GLint clip = x + count - rb->Width;
1469 rb->PutRow(ctx, rb, count, x, y,
1470 (const GLubyte *) values + skip * valueSize, NULL);
1475 * Wrapper for gl_renderbuffer::GetRow() which does clipping.
1476 * \param valueSize size of each value (pixel) in bytes
1479 _swrast_get_row(struct gl_context *ctx, struct gl_renderbuffer *rb,
1480 GLuint count, GLint x, GLint y,
1481 GLvoid *values, GLuint valueSize)
1485 if (y < 0 || y >= (GLint) rb->Height)
1486 return; /* above or below */
1488 if (x + (GLint) count <= 0 || x >= (GLint) rb->Width)
1489 return; /* entirely left or right */
1491 if (x + count > rb->Width) {
1493 GLint clip = x + count - rb->Width;
1504 rb->GetRow(ctx, rb, count, x, y, (GLubyte *) values + skip * valueSize);
1509 * Get RGBA pixels from the given renderbuffer.
1510 * Used by blending, logicop and masking functions.
1511 * \return pointer to the colors we read.
1514 _swrast_get_dest_rgba(struct gl_context *ctx, struct gl_renderbuffer *rb,
1517 const GLuint pixelSize = RGBA_PIXEL_SIZE(span->array->ChanType);
1520 /* Point rbPixels to a temporary space */
1521 rbPixels = span->array->attribs[FRAG_ATTRIB_MAX - 1];
1523 /* Get destination values from renderbuffer */
1524 if (span->arrayMask & SPAN_XY) {
1525 _swrast_get_values(ctx, rb, span->end, span->array->x, span->array->y,
1526 rbPixels, pixelSize);
1529 _swrast_get_row(ctx, rb, span->end, span->x, span->y,
1530 rbPixels, pixelSize);