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/format_pack.h"
37 #include "main/format_unpack.h"
38 #include "main/macros.h"
39 #include "main/imports.h"
40 #include "main/image.h"
42 #include "s_atifragshader.h"
45 #include "s_context.h"
49 #include "s_masking.h"
50 #include "s_fragprog.h"
52 #include "s_stencil.h"
53 #include "s_texcombine.h"
58 * Set default fragment attributes for the span using the
59 * current raster values. Used prior to glDraw/CopyPixels
63 _swrast_span_default_attribs(struct gl_context
*ctx
, SWspan
*span
)
68 const GLfloat depthMax
= ctx
->DrawBuffer
->_DepthMaxF
;
69 if (ctx
->DrawBuffer
->Visual
.depthBits
<= 16)
70 span
->z
= FloatToFixed(ctx
->Current
.RasterPos
[2] * depthMax
+ 0.5F
);
72 GLfloat tmpf
= ctx
->Current
.RasterPos
[2] * depthMax
;
73 tmpf
= MIN2(tmpf
, depthMax
);
74 span
->z
= (GLint
)tmpf
;
77 span
->interpMask
|= SPAN_Z
;
80 /* W (for perspective correction) */
81 span
->attrStart
[FRAG_ATTRIB_WPOS
][3] = 1.0;
82 span
->attrStepX
[FRAG_ATTRIB_WPOS
][3] = 0.0;
83 span
->attrStepY
[FRAG_ATTRIB_WPOS
][3] = 0.0;
85 /* primary color, or color index */
86 UNCLAMPED_FLOAT_TO_CHAN(r
, ctx
->Current
.RasterColor
[0]);
87 UNCLAMPED_FLOAT_TO_CHAN(g
, ctx
->Current
.RasterColor
[1]);
88 UNCLAMPED_FLOAT_TO_CHAN(b
, ctx
->Current
.RasterColor
[2]);
89 UNCLAMPED_FLOAT_TO_CHAN(a
, ctx
->Current
.RasterColor
[3]);
90 #if CHAN_TYPE == GL_FLOAT
96 span
->red
= IntToFixed(r
);
97 span
->green
= IntToFixed(g
);
98 span
->blue
= IntToFixed(b
);
99 span
->alpha
= IntToFixed(a
);
105 span
->interpMask
|= SPAN_RGBA
;
107 COPY_4V(span
->attrStart
[FRAG_ATTRIB_COL0
], ctx
->Current
.RasterColor
);
108 ASSIGN_4V(span
->attrStepX
[FRAG_ATTRIB_COL0
], 0.0, 0.0, 0.0, 0.0);
109 ASSIGN_4V(span
->attrStepY
[FRAG_ATTRIB_COL0
], 0.0, 0.0, 0.0, 0.0);
111 /* Secondary color */
112 if (ctx
->Light
.Enabled
|| ctx
->Fog
.ColorSumEnabled
)
114 COPY_4V(span
->attrStart
[FRAG_ATTRIB_COL1
], ctx
->Current
.RasterSecondaryColor
);
115 ASSIGN_4V(span
->attrStepX
[FRAG_ATTRIB_COL1
], 0.0, 0.0, 0.0, 0.0);
116 ASSIGN_4V(span
->attrStepY
[FRAG_ATTRIB_COL1
], 0.0, 0.0, 0.0, 0.0);
121 const SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
122 GLfloat fogVal
; /* a coord or a blend factor */
123 if (swrast
->_PreferPixelFog
) {
124 /* fog blend factors will be computed from fog coordinates per pixel */
125 fogVal
= ctx
->Current
.RasterDistance
;
128 /* fog blend factor should be computed from fogcoord now */
129 fogVal
= _swrast_z_to_fogfactor(ctx
, ctx
->Current
.RasterDistance
);
131 span
->attrStart
[FRAG_ATTRIB_FOGC
][0] = fogVal
;
132 span
->attrStepX
[FRAG_ATTRIB_FOGC
][0] = 0.0;
133 span
->attrStepY
[FRAG_ATTRIB_FOGC
][0] = 0.0;
139 for (i
= 0; i
< ctx
->Const
.MaxTextureCoordUnits
; i
++) {
140 const GLuint attr
= FRAG_ATTRIB_TEX0
+ i
;
141 const GLfloat
*tc
= ctx
->Current
.RasterTexCoords
[i
];
142 if (ctx
->FragmentProgram
._Current
|| ctx
->ATIFragmentShader
._Enabled
) {
143 COPY_4V(span
->attrStart
[attr
], tc
);
145 else if (tc
[3] > 0.0F
) {
146 /* use (s/q, t/q, r/q, 1) */
147 span
->attrStart
[attr
][0] = tc
[0] / tc
[3];
148 span
->attrStart
[attr
][1] = tc
[1] / tc
[3];
149 span
->attrStart
[attr
][2] = tc
[2] / tc
[3];
150 span
->attrStart
[attr
][3] = 1.0;
153 ASSIGN_4V(span
->attrStart
[attr
], 0.0F
, 0.0F
, 0.0F
, 1.0F
);
155 ASSIGN_4V(span
->attrStepX
[attr
], 0.0F
, 0.0F
, 0.0F
, 0.0F
);
156 ASSIGN_4V(span
->attrStepY
[attr
], 0.0F
, 0.0F
, 0.0F
, 0.0F
);
163 * Interpolate the active attributes (and'd with attrMask) to
164 * fill in span->array->attribs[].
165 * Perspective correction will be done. The point/line/triangle function
166 * should have computed attrStart/Step values for FRAG_ATTRIB_WPOS[3]!
169 interpolate_active_attribs(struct gl_context
*ctx
, SWspan
*span
,
170 GLbitfield64 attrMask
)
172 const SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
175 * Don't overwrite existing array values, such as colors that may have
176 * been produced by glDraw/CopyPixels.
178 attrMask
&= ~span
->arrayAttribs
;
181 if (attrMask
& BITFIELD64_BIT(attr
)) {
182 const GLfloat dwdx
= span
->attrStepX
[FRAG_ATTRIB_WPOS
][3];
183 GLfloat w
= span
->attrStart
[FRAG_ATTRIB_WPOS
][3];
184 const GLfloat dv0dx
= span
->attrStepX
[attr
][0];
185 const GLfloat dv1dx
= span
->attrStepX
[attr
][1];
186 const GLfloat dv2dx
= span
->attrStepX
[attr
][2];
187 const GLfloat dv3dx
= span
->attrStepX
[attr
][3];
188 GLfloat v0
= span
->attrStart
[attr
][0] + span
->leftClip
* dv0dx
;
189 GLfloat v1
= span
->attrStart
[attr
][1] + span
->leftClip
* dv1dx
;
190 GLfloat v2
= span
->attrStart
[attr
][2] + span
->leftClip
* dv2dx
;
191 GLfloat v3
= span
->attrStart
[attr
][3] + span
->leftClip
* dv3dx
;
193 for (k
= 0; k
< span
->end
; k
++) {
194 const GLfloat invW
= 1.0f
/ w
;
195 span
->array
->attribs
[attr
][k
][0] = v0
* invW
;
196 span
->array
->attribs
[attr
][k
][1] = v1
* invW
;
197 span
->array
->attribs
[attr
][k
][2] = v2
* invW
;
198 span
->array
->attribs
[attr
][k
][3] = v3
* invW
;
205 ASSERT((span
->arrayAttribs
& BITFIELD64_BIT(attr
)) == 0);
206 span
->arrayAttribs
|= BITFIELD64_BIT(attr
);
213 * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
217 interpolate_int_colors(struct gl_context
*ctx
, SWspan
*span
)
220 const GLuint n
= span
->end
;
223 ASSERT(!(span
->arrayMask
& SPAN_RGBA
));
226 switch (span
->array
->ChanType
) {
228 case GL_UNSIGNED_BYTE
:
230 GLubyte (*rgba
)[4] = span
->array
->rgba8
;
231 if (span
->interpMask
& SPAN_FLAT
) {
233 color
[RCOMP
] = FixedToInt(span
->red
);
234 color
[GCOMP
] = FixedToInt(span
->green
);
235 color
[BCOMP
] = FixedToInt(span
->blue
);
236 color
[ACOMP
] = FixedToInt(span
->alpha
);
237 for (i
= 0; i
< n
; i
++) {
238 COPY_4UBV(rgba
[i
], color
);
242 GLfixed r
= span
->red
;
243 GLfixed g
= span
->green
;
244 GLfixed b
= span
->blue
;
245 GLfixed a
= span
->alpha
;
246 GLint dr
= span
->redStep
;
247 GLint dg
= span
->greenStep
;
248 GLint db
= span
->blueStep
;
249 GLint da
= span
->alphaStep
;
250 for (i
= 0; i
< n
; i
++) {
251 rgba
[i
][RCOMP
] = FixedToChan(r
);
252 rgba
[i
][GCOMP
] = FixedToChan(g
);
253 rgba
[i
][BCOMP
] = FixedToChan(b
);
254 rgba
[i
][ACOMP
] = FixedToChan(a
);
263 case GL_UNSIGNED_SHORT
:
265 GLushort (*rgba
)[4] = span
->array
->rgba16
;
266 if (span
->interpMask
& SPAN_FLAT
) {
268 color
[RCOMP
] = FixedToInt(span
->red
);
269 color
[GCOMP
] = FixedToInt(span
->green
);
270 color
[BCOMP
] = FixedToInt(span
->blue
);
271 color
[ACOMP
] = FixedToInt(span
->alpha
);
272 for (i
= 0; i
< n
; i
++) {
273 COPY_4V(rgba
[i
], color
);
277 GLushort (*rgba
)[4] = span
->array
->rgba16
;
279 GLint dr
, dg
, db
, da
;
285 dg
= span
->greenStep
;
287 da
= span
->alphaStep
;
288 for (i
= 0; i
< n
; i
++) {
289 rgba
[i
][RCOMP
] = FixedToChan(r
);
290 rgba
[i
][GCOMP
] = FixedToChan(g
);
291 rgba
[i
][BCOMP
] = FixedToChan(b
);
292 rgba
[i
][ACOMP
] = FixedToChan(a
);
303 interpolate_active_attribs(ctx
, span
, FRAG_BIT_COL0
);
306 _mesa_problem(ctx
, "bad datatype 0x%x in interpolate_int_colors",
307 span
->array
->ChanType
);
309 span
->arrayMask
|= SPAN_RGBA
;
314 * Populate the FRAG_ATTRIB_COL0 array.
317 interpolate_float_colors(SWspan
*span
)
319 GLfloat (*col0
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL0
];
320 const GLuint n
= span
->end
;
323 assert(!(span
->arrayAttribs
& FRAG_BIT_COL0
));
325 if (span
->arrayMask
& SPAN_RGBA
) {
326 /* convert array of int colors */
327 for (i
= 0; i
< n
; i
++) {
328 col0
[i
][0] = UBYTE_TO_FLOAT(span
->array
->rgba8
[i
][0]);
329 col0
[i
][1] = UBYTE_TO_FLOAT(span
->array
->rgba8
[i
][1]);
330 col0
[i
][2] = UBYTE_TO_FLOAT(span
->array
->rgba8
[i
][2]);
331 col0
[i
][3] = UBYTE_TO_FLOAT(span
->array
->rgba8
[i
][3]);
335 /* interpolate red/green/blue/alpha to get float colors */
336 ASSERT(span
->interpMask
& SPAN_RGBA
);
337 if (span
->interpMask
& SPAN_FLAT
) {
338 GLfloat r
= FixedToFloat(span
->red
);
339 GLfloat g
= FixedToFloat(span
->green
);
340 GLfloat b
= FixedToFloat(span
->blue
);
341 GLfloat a
= FixedToFloat(span
->alpha
);
342 for (i
= 0; i
< n
; i
++) {
343 ASSIGN_4V(col0
[i
], r
, g
, b
, a
);
347 GLfloat r
= FixedToFloat(span
->red
);
348 GLfloat g
= FixedToFloat(span
->green
);
349 GLfloat b
= FixedToFloat(span
->blue
);
350 GLfloat a
= FixedToFloat(span
->alpha
);
351 GLfloat dr
= FixedToFloat(span
->redStep
);
352 GLfloat dg
= FixedToFloat(span
->greenStep
);
353 GLfloat db
= FixedToFloat(span
->blueStep
);
354 GLfloat da
= FixedToFloat(span
->alphaStep
);
355 for (i
= 0; i
< n
; i
++) {
368 span
->arrayAttribs
|= FRAG_BIT_COL0
;
369 span
->array
->ChanType
= GL_FLOAT
;
375 * Fill in the span.zArray array from the span->z, zStep values.
378 _swrast_span_interpolate_z( const struct gl_context
*ctx
, SWspan
*span
)
380 const GLuint n
= span
->end
;
383 ASSERT(!(span
->arrayMask
& SPAN_Z
));
385 if (ctx
->DrawBuffer
->Visual
.depthBits
<= 16) {
386 GLfixed zval
= span
->z
;
387 GLuint
*z
= span
->array
->z
;
388 for (i
= 0; i
< n
; i
++) {
389 z
[i
] = FixedToInt(zval
);
394 /* Deep Z buffer, no fixed->int shift */
395 GLuint zval
= span
->z
;
396 GLuint
*z
= span
->array
->z
;
397 for (i
= 0; i
< n
; i
++) {
402 span
->interpMask
&= ~SPAN_Z
;
403 span
->arrayMask
|= SPAN_Z
;
408 * Compute mipmap LOD from partial derivatives.
409 * This the ideal solution, as given in the OpenGL spec.
412 _swrast_compute_lambda(GLfloat dsdx
, GLfloat dsdy
, GLfloat dtdx
, GLfloat dtdy
,
413 GLfloat dqdx
, GLfloat dqdy
, GLfloat texW
, GLfloat texH
,
414 GLfloat s
, GLfloat t
, GLfloat q
, GLfloat invQ
)
416 GLfloat dudx
= texW
* ((s
+ dsdx
) / (q
+ dqdx
) - s
* invQ
);
417 GLfloat dvdx
= texH
* ((t
+ dtdx
) / (q
+ dqdx
) - t
* invQ
);
418 GLfloat dudy
= texW
* ((s
+ dsdy
) / (q
+ dqdy
) - s
* invQ
);
419 GLfloat dvdy
= texH
* ((t
+ dtdy
) / (q
+ dqdy
) - t
* invQ
);
420 GLfloat x
= SQRTF(dudx
* dudx
+ dvdx
* dvdx
);
421 GLfloat y
= SQRTF(dudy
* dudy
+ dvdy
* dvdy
);
422 GLfloat rho
= MAX2(x
, y
);
423 GLfloat lambda
= LOG2(rho
);
429 * Compute mipmap LOD from partial derivatives.
430 * This is a faster approximation than above function.
434 _swrast_compute_lambda(GLfloat dsdx
, GLfloat dsdy
, GLfloat dtdx
, GLfloat dtdy
,
435 GLfloat dqdx
, GLfloat dqdy
, GLfloat texW
, GLfloat texH
,
436 GLfloat s
, GLfloat t
, GLfloat q
, GLfloat invQ
)
438 GLfloat dsdx2
= (s
+ dsdx
) / (q
+ dqdx
) - s
* invQ
;
439 GLfloat dtdx2
= (t
+ dtdx
) / (q
+ dqdx
) - t
* invQ
;
440 GLfloat dsdy2
= (s
+ dsdy
) / (q
+ dqdy
) - s
* invQ
;
441 GLfloat dtdy2
= (t
+ dtdy
) / (q
+ dqdy
) - t
* invQ
;
442 GLfloat maxU
, maxV
, rho
, lambda
;
443 dsdx2
= FABSF(dsdx2
);
444 dsdy2
= FABSF(dsdy2
);
445 dtdx2
= FABSF(dtdx2
);
446 dtdy2
= FABSF(dtdy2
);
447 maxU
= MAX2(dsdx2
, dsdy2
) * texW
;
448 maxV
= MAX2(dtdx2
, dtdy2
) * texH
;
449 rho
= MAX2(maxU
, maxV
);
457 * Fill in the span.array->attrib[FRAG_ATTRIB_TEXn] arrays from the
458 * using the attrStart/Step values.
460 * This function only used during fixed-function fragment processing.
462 * Note: in the places where we divide by Q (or mult by invQ) we're
463 * really doing two things: perspective correction and texcoord
464 * projection. Remember, for texcoord (s,t,r,q) we need to index
465 * texels with (s/q, t/q, r/q).
468 interpolate_texcoords(struct gl_context
*ctx
, SWspan
*span
)
471 = (ctx
->Texture
._EnabledCoordUnits
> 1) ? ctx
->Const
.MaxTextureUnits
: 1;
474 /* XXX CoordUnits vs. ImageUnits */
475 for (u
= 0; u
< maxUnit
; u
++) {
476 if (ctx
->Texture
._EnabledCoordUnits
& (1 << u
)) {
477 const GLuint attr
= FRAG_ATTRIB_TEX0
+ u
;
478 const struct gl_texture_object
*obj
= ctx
->Texture
.Unit
[u
]._Current
;
480 GLboolean needLambda
;
481 GLfloat (*texcoord
)[4] = span
->array
->attribs
[attr
];
482 GLfloat
*lambda
= span
->array
->lambda
[u
];
483 const GLfloat dsdx
= span
->attrStepX
[attr
][0];
484 const GLfloat dsdy
= span
->attrStepY
[attr
][0];
485 const GLfloat dtdx
= span
->attrStepX
[attr
][1];
486 const GLfloat dtdy
= span
->attrStepY
[attr
][1];
487 const GLfloat drdx
= span
->attrStepX
[attr
][2];
488 const GLfloat dqdx
= span
->attrStepX
[attr
][3];
489 const GLfloat dqdy
= span
->attrStepY
[attr
][3];
490 GLfloat s
= span
->attrStart
[attr
][0] + span
->leftClip
* dsdx
;
491 GLfloat t
= span
->attrStart
[attr
][1] + span
->leftClip
* dtdx
;
492 GLfloat r
= span
->attrStart
[attr
][2] + span
->leftClip
* drdx
;
493 GLfloat q
= span
->attrStart
[attr
][3] + span
->leftClip
* dqdx
;
496 const struct gl_texture_image
*img
= obj
->Image
[0][obj
->BaseLevel
];
497 const struct swrast_texture_image
*swImg
=
498 swrast_texture_image_const(img
);
500 needLambda
= (obj
->Sampler
.MinFilter
!= obj
->Sampler
.MagFilter
)
501 || ctx
->FragmentProgram
._Current
;
502 /* LOD is calculated directly in the ansiotropic filter, we can
503 * skip the normal lambda function as the result is ignored.
505 if (obj
->Sampler
.MaxAnisotropy
> 1.0 &&
506 obj
->Sampler
.MinFilter
== GL_LINEAR_MIPMAP_LINEAR
) {
507 needLambda
= GL_FALSE
;
509 texW
= swImg
->WidthScale
;
510 texH
= swImg
->HeightScale
;
513 /* using a fragment program */
516 needLambda
= GL_FALSE
;
521 if (ctx
->FragmentProgram
._Current
522 || ctx
->ATIFragmentShader
._Enabled
) {
523 /* do perspective correction but don't divide s, t, r by q */
524 const GLfloat dwdx
= span
->attrStepX
[FRAG_ATTRIB_WPOS
][3];
525 GLfloat w
= span
->attrStart
[FRAG_ATTRIB_WPOS
][3] + span
->leftClip
* dwdx
;
526 for (i
= 0; i
< span
->end
; i
++) {
527 const GLfloat invW
= 1.0F
/ w
;
528 texcoord
[i
][0] = s
* invW
;
529 texcoord
[i
][1] = t
* invW
;
530 texcoord
[i
][2] = r
* invW
;
531 texcoord
[i
][3] = q
* invW
;
532 lambda
[i
] = _swrast_compute_lambda(dsdx
, dsdy
, dtdx
, dtdy
,
533 dqdx
, dqdy
, texW
, texH
,
543 for (i
= 0; i
< span
->end
; i
++) {
544 const GLfloat invQ
= (q
== 0.0F
) ? 1.0F
: (1.0F
/ q
);
545 texcoord
[i
][0] = s
* invQ
;
546 texcoord
[i
][1] = t
* invQ
;
547 texcoord
[i
][2] = r
* invQ
;
549 lambda
[i
] = _swrast_compute_lambda(dsdx
, dsdy
, dtdx
, dtdy
,
550 dqdx
, dqdy
, texW
, texH
,
558 span
->arrayMask
|= SPAN_LAMBDA
;
562 if (ctx
->FragmentProgram
._Current
||
563 ctx
->ATIFragmentShader
._Enabled
) {
564 /* do perspective correction but don't divide s, t, r by q */
565 const GLfloat dwdx
= span
->attrStepX
[FRAG_ATTRIB_WPOS
][3];
566 GLfloat w
= span
->attrStart
[FRAG_ATTRIB_WPOS
][3] + span
->leftClip
* dwdx
;
567 for (i
= 0; i
< span
->end
; i
++) {
568 const GLfloat invW
= 1.0F
/ w
;
569 texcoord
[i
][0] = s
* invW
;
570 texcoord
[i
][1] = t
* invW
;
571 texcoord
[i
][2] = r
* invW
;
572 texcoord
[i
][3] = q
* invW
;
581 else if (dqdx
== 0.0F
) {
582 /* Ortho projection or polygon's parallel to window X axis */
583 const GLfloat invQ
= (q
== 0.0F
) ? 1.0F
: (1.0F
/ q
);
584 for (i
= 0; i
< span
->end
; i
++) {
585 texcoord
[i
][0] = s
* invQ
;
586 texcoord
[i
][1] = t
* invQ
;
587 texcoord
[i
][2] = r
* invQ
;
596 for (i
= 0; i
< span
->end
; i
++) {
597 const GLfloat invQ
= (q
== 0.0F
) ? 1.0F
: (1.0F
/ q
);
598 texcoord
[i
][0] = s
* invQ
;
599 texcoord
[i
][1] = t
* invQ
;
600 texcoord
[i
][2] = r
* invQ
;
616 * Fill in the arrays->attribs[FRAG_ATTRIB_WPOS] array.
619 interpolate_wpos(struct gl_context
*ctx
, SWspan
*span
)
621 GLfloat (*wpos
)[4] = span
->array
->attribs
[FRAG_ATTRIB_WPOS
];
623 const GLfloat zScale
= 1.0F
/ ctx
->DrawBuffer
->_DepthMaxF
;
626 if (span
->arrayMask
& SPAN_XY
) {
627 for (i
= 0; i
< span
->end
; i
++) {
628 wpos
[i
][0] = (GLfloat
) span
->array
->x
[i
];
629 wpos
[i
][1] = (GLfloat
) span
->array
->y
[i
];
633 for (i
= 0; i
< span
->end
; i
++) {
634 wpos
[i
][0] = (GLfloat
) span
->x
+ i
;
635 wpos
[i
][1] = (GLfloat
) span
->y
;
639 dw
= span
->attrStepX
[FRAG_ATTRIB_WPOS
][3];
640 w
= span
->attrStart
[FRAG_ATTRIB_WPOS
][3] + span
->leftClip
* dw
;
641 for (i
= 0; i
< span
->end
; i
++) {
642 wpos
[i
][2] = (GLfloat
) span
->array
->z
[i
] * zScale
;
650 * Apply the current polygon stipple pattern to a span of pixels.
653 stipple_polygon_span(struct gl_context
*ctx
, SWspan
*span
)
655 GLubyte
*mask
= span
->array
->mask
;
657 ASSERT(ctx
->Polygon
.StippleFlag
);
659 if (span
->arrayMask
& SPAN_XY
) {
660 /* arrays of x/y pixel coords */
662 for (i
= 0; i
< span
->end
; i
++) {
663 const GLint col
= span
->array
->x
[i
] % 32;
664 const GLint row
= span
->array
->y
[i
] % 32;
665 const GLuint stipple
= ctx
->PolygonStipple
[row
];
666 if (((1 << col
) & stipple
) == 0) {
672 /* horizontal span of pixels */
673 const GLuint highBit
= 1 << 31;
674 const GLuint stipple
= ctx
->PolygonStipple
[span
->y
% 32];
675 GLuint i
, m
= highBit
>> (GLuint
) (span
->x
% 32);
676 for (i
= 0; i
< span
->end
; i
++) {
677 if ((m
& stipple
) == 0) {
686 span
->writeAll
= GL_FALSE
;
691 * Clip a pixel span to the current buffer/window boundaries:
692 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
693 * window clipping and scissoring.
694 * Return: GL_TRUE some pixels still visible
695 * GL_FALSE nothing visible
698 clip_span( struct gl_context
*ctx
, SWspan
*span
)
700 const GLint xmin
= ctx
->DrawBuffer
->_Xmin
;
701 const GLint xmax
= ctx
->DrawBuffer
->_Xmax
;
702 const GLint ymin
= ctx
->DrawBuffer
->_Ymin
;
703 const GLint ymax
= ctx
->DrawBuffer
->_Ymax
;
707 if (span
->arrayMask
& SPAN_XY
) {
708 /* arrays of x/y pixel coords */
709 const GLint
*x
= span
->array
->x
;
710 const GLint
*y
= span
->array
->y
;
711 const GLint n
= span
->end
;
712 GLubyte
*mask
= span
->array
->mask
;
715 if (span
->arrayMask
& SPAN_MASK
) {
716 /* note: using & intead of && to reduce branches */
717 for (i
= 0; i
< n
; i
++) {
718 mask
[i
] &= (x
[i
] >= xmin
) & (x
[i
] < xmax
)
719 & (y
[i
] >= ymin
) & (y
[i
] < ymax
);
724 /* note: using & intead of && to reduce branches */
725 for (i
= 0; i
< n
; i
++) {
726 mask
[i
] = (x
[i
] >= xmin
) & (x
[i
] < xmax
)
727 & (y
[i
] >= ymin
) & (y
[i
] < ymax
);
734 /* horizontal span of pixels */
735 const GLint x
= span
->x
;
736 const GLint y
= span
->y
;
739 /* Trivial rejection tests */
740 if (y
< ymin
|| y
>= ymax
|| x
+ n
<= xmin
|| x
>= xmax
) {
742 return GL_FALSE
; /* all pixels clipped */
748 n
= span
->end
= xmax
- x
;
751 /* Clip to the left */
753 const GLint leftClip
= xmin
- x
;
756 ASSERT(leftClip
> 0);
757 ASSERT(x
+ n
> xmin
);
759 /* Clip 'leftClip' pixels from the left side.
760 * The span->leftClip field will be applied when we interpolate
761 * fragment attributes.
762 * For arrays of values, shift them left.
764 for (i
= 0; i
< FRAG_ATTRIB_MAX
; i
++) {
765 if (span
->interpMask
& (1 << i
)) {
767 for (j
= 0; j
< 4; j
++) {
768 span
->attrStart
[i
][j
] += leftClip
* span
->attrStepX
[i
][j
];
773 span
->red
+= leftClip
* span
->redStep
;
774 span
->green
+= leftClip
* span
->greenStep
;
775 span
->blue
+= leftClip
* span
->blueStep
;
776 span
->alpha
+= leftClip
* span
->alphaStep
;
777 span
->index
+= leftClip
* span
->indexStep
;
778 span
->z
+= leftClip
* span
->zStep
;
779 span
->intTex
[0] += leftClip
* span
->intTexStep
[0];
780 span
->intTex
[1] += leftClip
* span
->intTexStep
[1];
782 #define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
783 memmove(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
785 for (i
= 0; i
< FRAG_ATTRIB_MAX
; i
++) {
786 if (span
->arrayAttribs
& (1 << i
)) {
787 /* shift array elements left by 'leftClip' */
788 SHIFT_ARRAY(span
->array
->attribs
[i
], leftClip
, n
- leftClip
);
792 SHIFT_ARRAY(span
->array
->mask
, leftClip
, n
- leftClip
);
793 SHIFT_ARRAY(span
->array
->rgba8
, leftClip
, n
- leftClip
);
794 SHIFT_ARRAY(span
->array
->rgba16
, leftClip
, n
- leftClip
);
795 SHIFT_ARRAY(span
->array
->x
, leftClip
, n
- leftClip
);
796 SHIFT_ARRAY(span
->array
->y
, leftClip
, n
- leftClip
);
797 SHIFT_ARRAY(span
->array
->z
, leftClip
, n
- leftClip
);
798 SHIFT_ARRAY(span
->array
->index
, leftClip
, n
- leftClip
);
799 for (i
= 0; i
< MAX_TEXTURE_COORD_UNITS
; i
++) {
800 SHIFT_ARRAY(span
->array
->lambda
[i
], leftClip
, n
- leftClip
);
802 SHIFT_ARRAY(span
->array
->coverage
, leftClip
, n
- leftClip
);
806 span
->leftClip
= leftClip
;
808 span
->end
-= leftClip
;
809 span
->writeAll
= GL_FALSE
;
812 ASSERT(span
->x
>= xmin
);
813 ASSERT(span
->x
+ span
->end
<= xmax
);
814 ASSERT(span
->y
>= ymin
);
815 ASSERT(span
->y
< ymax
);
817 return GL_TRUE
; /* some pixels visible */
823 * Add specular colors to primary colors.
824 * Only called during fixed-function operation.
825 * Result is float color array (FRAG_ATTRIB_COL0).
828 add_specular(struct gl_context
*ctx
, SWspan
*span
)
830 const SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
831 const GLubyte
*mask
= span
->array
->mask
;
832 GLfloat (*col0
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL0
];
833 GLfloat (*col1
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL1
];
836 ASSERT(!ctx
->FragmentProgram
._Current
);
837 ASSERT(span
->arrayMask
& SPAN_RGBA
);
838 ASSERT(swrast
->_ActiveAttribMask
& FRAG_BIT_COL1
);
839 (void) swrast
; /* silence warning */
841 if (span
->array
->ChanType
== GL_FLOAT
) {
842 if ((span
->arrayAttribs
& FRAG_BIT_COL0
) == 0) {
843 interpolate_active_attribs(ctx
, span
, FRAG_BIT_COL0
);
847 /* need float colors */
848 if ((span
->arrayAttribs
& FRAG_BIT_COL0
) == 0) {
849 interpolate_float_colors(span
);
853 if ((span
->arrayAttribs
& FRAG_BIT_COL1
) == 0) {
854 /* XXX could avoid this and interpolate COL1 in the loop below */
855 interpolate_active_attribs(ctx
, span
, FRAG_BIT_COL1
);
858 ASSERT(span
->arrayAttribs
& FRAG_BIT_COL0
);
859 ASSERT(span
->arrayAttribs
& FRAG_BIT_COL1
);
861 for (i
= 0; i
< span
->end
; i
++) {
863 col0
[i
][0] += col1
[i
][0];
864 col0
[i
][1] += col1
[i
][1];
865 col0
[i
][2] += col1
[i
][2];
869 span
->array
->ChanType
= GL_FLOAT
;
874 * Apply antialiasing coverage value to alpha values.
877 apply_aa_coverage(SWspan
*span
)
879 const GLfloat
*coverage
= span
->array
->coverage
;
881 if (span
->array
->ChanType
== GL_UNSIGNED_BYTE
) {
882 GLubyte (*rgba
)[4] = span
->array
->rgba8
;
883 for (i
= 0; i
< span
->end
; i
++) {
884 const GLfloat a
= rgba
[i
][ACOMP
] * coverage
[i
];
885 rgba
[i
][ACOMP
] = (GLubyte
) CLAMP(a
, 0.0, 255.0);
886 ASSERT(coverage
[i
] >= 0.0);
887 ASSERT(coverage
[i
] <= 1.0);
890 else if (span
->array
->ChanType
== GL_UNSIGNED_SHORT
) {
891 GLushort (*rgba
)[4] = span
->array
->rgba16
;
892 for (i
= 0; i
< span
->end
; i
++) {
893 const GLfloat a
= rgba
[i
][ACOMP
] * coverage
[i
];
894 rgba
[i
][ACOMP
] = (GLushort
) CLAMP(a
, 0.0, 65535.0);
898 GLfloat (*rgba
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL0
];
899 for (i
= 0; i
< span
->end
; i
++) {
900 rgba
[i
][ACOMP
] = rgba
[i
][ACOMP
] * coverage
[i
];
908 * Clamp span's float colors to [0,1]
911 clamp_colors(SWspan
*span
)
913 GLfloat (*rgba
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL0
];
915 ASSERT(span
->array
->ChanType
== GL_FLOAT
);
916 for (i
= 0; i
< span
->end
; i
++) {
917 rgba
[i
][RCOMP
] = CLAMP(rgba
[i
][RCOMP
], 0.0F
, 1.0F
);
918 rgba
[i
][GCOMP
] = CLAMP(rgba
[i
][GCOMP
], 0.0F
, 1.0F
);
919 rgba
[i
][BCOMP
] = CLAMP(rgba
[i
][BCOMP
], 0.0F
, 1.0F
);
920 rgba
[i
][ACOMP
] = CLAMP(rgba
[i
][ACOMP
], 0.0F
, 1.0F
);
926 * Convert the span's color arrays to the given type.
927 * The only way 'output' can be greater than zero is when we have a fragment
928 * program that writes to gl_FragData[1] or higher.
929 * \param output which fragment program color output is being processed
932 convert_color_type(SWspan
*span
, GLenum newType
, GLuint output
)
936 if (output
> 0 || span
->array
->ChanType
== GL_FLOAT
) {
937 src
= span
->array
->attribs
[FRAG_ATTRIB_COL0
+ output
];
938 span
->array
->ChanType
= GL_FLOAT
;
940 else if (span
->array
->ChanType
== GL_UNSIGNED_BYTE
) {
941 src
= span
->array
->rgba8
;
944 ASSERT(span
->array
->ChanType
== GL_UNSIGNED_SHORT
);
945 src
= span
->array
->rgba16
;
948 if (newType
== GL_UNSIGNED_BYTE
) {
949 dst
= span
->array
->rgba8
;
951 else if (newType
== GL_UNSIGNED_SHORT
) {
952 dst
= span
->array
->rgba16
;
955 dst
= span
->array
->attribs
[FRAG_ATTRIB_COL0
];
958 _mesa_convert_colors(span
->array
->ChanType
, src
,
960 span
->end
, span
->array
->mask
);
962 span
->array
->ChanType
= newType
;
963 span
->array
->rgba
= dst
;
969 * Apply fragment shader, fragment program or normal texturing to span.
972 shade_texture_span(struct gl_context
*ctx
, SWspan
*span
)
974 /* This is a hack to work around drivers such as i965 that:
976 * - Set _MaintainTexEnvProgram to generate GLSL IR for
977 * fixed-function fragment processing.
978 * - Don't call _mesa_ir_link_shader to generate Mesa IR from
980 * - May use swrast to handle glDrawPixels.
982 * Since _mesa_ir_link_shader is never called, there is no Mesa IR
983 * to execute. Instead do regular fixed-function processing.
985 * It is also worth noting that the software fixed-function path is
986 * much faster than the software shader path.
988 const bool use_fragment_program
=
989 ctx
->FragmentProgram
._Current
990 && ctx
->FragmentProgram
._Current
!= ctx
->FragmentProgram
._TexEnvProgram
;
992 if (use_fragment_program
||
993 ctx
->ATIFragmentShader
._Enabled
) {
994 /* programmable shading */
995 if (span
->primitive
== GL_BITMAP
&& span
->array
->ChanType
!= GL_FLOAT
) {
996 convert_color_type(span
, GL_FLOAT
, 0);
999 span
->array
->rgba
= (void *) span
->array
->attribs
[FRAG_ATTRIB_COL0
];
1002 if (span
->primitive
!= GL_POINT
||
1003 (span
->interpMask
& SPAN_RGBA
) ||
1004 ctx
->Point
.PointSprite
) {
1005 /* for single-pixel points, we populated the arrays already */
1006 interpolate_active_attribs(ctx
, span
, ~0);
1008 span
->array
->ChanType
= GL_FLOAT
;
1010 if (!(span
->arrayMask
& SPAN_Z
))
1011 _swrast_span_interpolate_z (ctx
, span
);
1014 if (inputsRead
& FRAG_BIT_WPOS
)
1016 /* XXX always interpolate wpos so that DDX/DDY work */
1018 interpolate_wpos(ctx
, span
);
1020 /* Run fragment program/shader now */
1021 if (use_fragment_program
) {
1022 _swrast_exec_fragment_program(ctx
, span
);
1025 ASSERT(ctx
->ATIFragmentShader
._Enabled
);
1026 _swrast_exec_fragment_shader(ctx
, span
);
1029 else if (ctx
->Texture
._EnabledCoordUnits
) {
1030 /* conventional texturing */
1033 if ((span
->arrayAttribs
& FRAG_BIT_COL0
) == 0) {
1034 interpolate_int_colors(ctx
, span
);
1037 if (!(span
->arrayMask
& SPAN_RGBA
))
1038 interpolate_int_colors(ctx
, span
);
1040 if ((span
->arrayAttribs
& FRAG_BITS_TEX_ANY
) == 0x0)
1041 interpolate_texcoords(ctx
, span
);
1043 _swrast_texture_span(ctx
, span
);
1048 /** Put colors at x/y locations into a renderbuffer */
1050 put_values(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1052 GLuint count
, const GLint x
[], const GLint y
[],
1053 const void *values
, const GLubyte
*mask
)
1055 gl_pack_ubyte_rgba_func pack_ubyte
;
1056 gl_pack_float_rgba_func pack_float
;
1059 if (datatype
== GL_UNSIGNED_BYTE
)
1060 pack_ubyte
= _mesa_get_pack_ubyte_rgba_function(rb
->Format
);
1062 pack_float
= _mesa_get_pack_float_rgba_function(rb
->Format
);
1064 for (i
= 0; i
< count
; i
++) {
1066 GLubyte
*dst
= _swrast_pixel_address(rb
, x
[i
], y
[i
]);
1068 if (datatype
== GL_UNSIGNED_BYTE
) {
1069 pack_ubyte((const GLubyte
*) values
+ 4 * i
, dst
);
1072 assert(datatype
== GL_FLOAT
);
1073 pack_float((const GLfloat
*) values
+ 4 * i
, dst
);
1080 /** Put row of colors into renderbuffer */
1082 _swrast_put_row(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1084 GLuint count
, GLint x
, GLint y
,
1085 const void *values
, const GLubyte
*mask
)
1087 GLubyte
*dst
= _swrast_pixel_address(rb
, x
, y
);
1090 if (datatype
== GL_UNSIGNED_BYTE
) {
1091 _mesa_pack_ubyte_rgba_row(rb
->Format
, count
,
1092 (const GLubyte (*)[4]) values
, dst
);
1095 assert(datatype
== GL_FLOAT
);
1096 _mesa_pack_float_rgba_row(rb
->Format
, count
,
1097 (const GLfloat (*)[4]) values
, dst
);
1101 const GLuint bpp
= _mesa_get_format_bytes(rb
->Format
);
1102 GLuint i
, runLen
, runStart
;
1103 /* We can't pass a 'mask' array to the _mesa_pack_rgba_row() functions
1104 * so look for runs where mask=1...
1107 for (i
= 0; i
< count
; i
++) {
1114 if (!mask
[i
] || i
== count
- 1) {
1115 /* might be the end of a run of pixels */
1117 if (datatype
== GL_UNSIGNED_BYTE
) {
1118 _mesa_pack_ubyte_rgba_row(rb
->Format
, runLen
,
1119 (const GLubyte (*)[4]) values
+ runStart
,
1120 dst
+ runStart
* bpp
);
1123 assert(datatype
== GL_FLOAT
);
1124 _mesa_pack_float_rgba_row(rb
->Format
, runLen
,
1125 (const GLfloat (*)[4]) values
+ runStart
,
1126 dst
+ runStart
* bpp
);
1138 * Apply all the per-fragment operations to a span.
1139 * This now includes texturing (_swrast_write_texture_span() is history).
1140 * This function may modify any of the array values in the span.
1141 * span->interpMask and span->arrayMask may be changed but will be restored
1142 * to their original values before returning.
1145 _swrast_write_rgba_span( struct gl_context
*ctx
, SWspan
*span
)
1147 const SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
1148 const GLuint
*colorMask
= (GLuint
*) ctx
->Color
.ColorMask
;
1149 const GLbitfield origInterpMask
= span
->interpMask
;
1150 const GLbitfield origArrayMask
= span
->arrayMask
;
1151 const GLbitfield64 origArrayAttribs
= span
->arrayAttribs
;
1152 const GLenum origChanType
= span
->array
->ChanType
;
1153 void * const origRgba
= span
->array
->rgba
;
1154 const GLboolean shader
= (ctx
->FragmentProgram
._Current
1155 || ctx
->ATIFragmentShader
._Enabled
);
1156 const GLboolean shaderOrTexture
= shader
|| ctx
->Texture
._EnabledCoordUnits
;
1157 struct gl_framebuffer
*fb
= ctx
->DrawBuffer
;
1160 printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__,
1161 span->interpMask, span->arrayMask);
1164 ASSERT(span
->primitive
== GL_POINT
||
1165 span
->primitive
== GL_LINE
||
1166 span
->primitive
== GL_POLYGON
||
1167 span
->primitive
== GL_BITMAP
);
1169 /* Fragment write masks */
1170 if (span
->arrayMask
& SPAN_MASK
) {
1171 /* mask was initialized by caller, probably glBitmap */
1172 span
->writeAll
= GL_FALSE
;
1175 memset(span
->array
->mask
, 1, span
->end
);
1176 span
->writeAll
= GL_TRUE
;
1179 /* Clip to window/scissor box */
1180 if (!clip_span(ctx
, span
)) {
1184 ASSERT(span
->end
<= MAX_WIDTH
);
1186 /* Depth bounds test */
1187 if (ctx
->Depth
.BoundsTest
&& fb
->Visual
.depthBits
> 0) {
1188 if (!_swrast_depth_bounds_test(ctx
, span
)) {
1194 /* Make sure all fragments are within window bounds */
1195 if (span
->arrayMask
& SPAN_XY
) {
1196 /* array of pixel locations */
1198 for (i
= 0; i
< span
->end
; i
++) {
1199 if (span
->array
->mask
[i
]) {
1200 assert(span
->array
->x
[i
] >= fb
->_Xmin
);
1201 assert(span
->array
->x
[i
] < fb
->_Xmax
);
1202 assert(span
->array
->y
[i
] >= fb
->_Ymin
);
1203 assert(span
->array
->y
[i
] < fb
->_Ymax
);
1209 /* Polygon Stippling */
1210 if (ctx
->Polygon
.StippleFlag
&& span
->primitive
== GL_POLYGON
) {
1211 stipple_polygon_span(ctx
, span
);
1214 /* This is the normal place to compute the fragment color/Z
1215 * from texturing or shading.
1217 if (shaderOrTexture
&& !swrast
->_DeferredTexture
) {
1218 shade_texture_span(ctx
, span
);
1221 /* Do the alpha test */
1222 if (ctx
->Color
.AlphaEnabled
) {
1223 if (!_swrast_alpha_test(ctx
, span
)) {
1224 /* all fragments failed test */
1229 /* Stencil and Z testing */
1230 if (ctx
->Stencil
._Enabled
|| ctx
->Depth
.Test
) {
1231 if (!(span
->arrayMask
& SPAN_Z
))
1232 _swrast_span_interpolate_z(ctx
, span
);
1234 if (ctx
->Transform
.DepthClamp
)
1235 _swrast_depth_clamp_span(ctx
, span
);
1237 if (ctx
->Stencil
._Enabled
) {
1238 /* Combined Z/stencil tests */
1239 if (!_swrast_stencil_and_ztest_span(ctx
, span
)) {
1240 /* all fragments failed test */
1244 else if (fb
->Visual
.depthBits
> 0) {
1245 /* Just regular depth testing */
1246 ASSERT(ctx
->Depth
.Test
);
1247 ASSERT(span
->arrayMask
& SPAN_Z
);
1248 if (!_swrast_depth_test_span(ctx
, span
)) {
1249 /* all fragments failed test */
1255 if (ctx
->Query
.CurrentOcclusionObject
) {
1256 /* update count of 'passed' fragments */
1257 struct gl_query_object
*q
= ctx
->Query
.CurrentOcclusionObject
;
1259 for (i
= 0; i
< span
->end
; i
++)
1260 q
->Result
+= span
->array
->mask
[i
];
1263 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1264 * the occlusion test.
1266 if (fb
->_NumColorDrawBuffers
== 1 && colorMask
[0] == 0x0) {
1267 /* no colors to write */
1271 /* If we were able to defer fragment color computation to now, there's
1272 * a good chance that many fragments will have already been killed by
1273 * Z/stencil testing.
1275 if (shaderOrTexture
&& swrast
->_DeferredTexture
) {
1276 shade_texture_span(ctx
, span
);
1280 if ((span
->arrayAttribs
& FRAG_BIT_COL0
) == 0) {
1281 interpolate_active_attribs(ctx
, span
, FRAG_BIT_COL0
);
1284 if ((span
->arrayMask
& SPAN_RGBA
) == 0) {
1285 interpolate_int_colors(ctx
, span
);
1289 ASSERT(span
->arrayMask
& SPAN_RGBA
);
1291 if (span
->primitive
== GL_BITMAP
|| !swrast
->SpecularVertexAdd
) {
1292 /* Add primary and specular (diffuse + specular) colors */
1294 if (ctx
->Fog
.ColorSumEnabled
||
1295 (ctx
->Light
.Enabled
&&
1296 ctx
->Light
.Model
.ColorControl
== GL_SEPARATE_SPECULAR_COLOR
)) {
1297 add_specular(ctx
, span
);
1303 if (swrast
->_FogEnabled
) {
1304 _swrast_fog_rgba_span(ctx
, span
);
1307 /* Antialias coverage application */
1308 if (span
->arrayMask
& SPAN_COVERAGE
) {
1309 apply_aa_coverage(span
);
1312 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1313 if (ctx
->Color
.ClampFragmentColor
== GL_TRUE
&&
1314 span
->array
->ChanType
== GL_FLOAT
) {
1319 * Write to renderbuffers.
1320 * Depending on glDrawBuffer() state and the which color outputs are
1321 * written by the fragment shader, we may either replicate one color to
1322 * all renderbuffers or write a different color to each renderbuffer.
1323 * multiFragOutputs=TRUE for the later case.
1326 const GLuint numBuffers
= fb
->_NumColorDrawBuffers
;
1327 const struct gl_fragment_program
*fp
= ctx
->FragmentProgram
._Current
;
1328 const GLboolean multiFragOutputs
=
1329 (fp
&& fp
->Base
.OutputsWritten
>= (1 << FRAG_RESULT_DATA0
));
1332 for (buf
= 0; buf
< numBuffers
; buf
++) {
1333 struct gl_renderbuffer
*rb
= fb
->_ColorDrawBuffers
[buf
];
1335 /* color[fragOutput] will be written to buffer[buf] */
1338 GLchan rgbaSave
[MAX_WIDTH
][4];
1340 if (span
->array
->ChanType
== GL_UNSIGNED_BYTE
) {
1341 span
->array
->rgba
= span
->array
->rgba8
;
1344 span
->array
->rgba
= (void *)
1345 span
->array
->attribs
[FRAG_ATTRIB_COL0
];
1348 if (!multiFragOutputs
&& numBuffers
> 1) {
1349 /* save colors for second, third renderbuffer writes */
1350 memcpy(rgbaSave
, span
->array
->rgba
,
1351 4 * span
->end
* sizeof(GLchan
));
1354 ASSERT(rb
->_BaseFormat
== GL_RGBA
||
1355 rb
->_BaseFormat
== GL_RGB
||
1356 rb
->_BaseFormat
== GL_RED
||
1357 rb
->_BaseFormat
== GL_RG
||
1358 rb
->_BaseFormat
== GL_ALPHA
);
1360 if (ctx
->Color
.ColorLogicOpEnabled
) {
1361 _swrast_logicop_rgba_span(ctx
, rb
, span
);
1363 else if ((ctx
->Color
.BlendEnabled
>> buf
) & 1) {
1364 _swrast_blend_span(ctx
, rb
, span
);
1367 if (colorMask
[buf
] != 0xffffffff) {
1368 _swrast_mask_rgba_span(ctx
, rb
, span
, buf
);
1371 if (span
->arrayMask
& SPAN_XY
) {
1372 /* array of pixel coords */
1374 span
->array
->ChanType
, span
->end
,
1375 span
->array
->x
, span
->array
->y
,
1376 span
->array
->rgba
, span
->array
->mask
);
1379 /* horizontal run of pixels */
1380 _swrast_put_row(ctx
, rb
,
1381 span
->array
->ChanType
,
1382 span
->end
, span
->x
, span
->y
,
1384 span
->writeAll
? NULL
: span
->array
->mask
);
1387 if (!multiFragOutputs
&& numBuffers
> 1) {
1388 /* restore original span values */
1389 memcpy(span
->array
->rgba
, rgbaSave
,
1390 4 * span
->end
* sizeof(GLchan
));
1398 /* restore these values before returning */
1399 span
->interpMask
= origInterpMask
;
1400 span
->arrayMask
= origArrayMask
;
1401 span
->arrayAttribs
= origArrayAttribs
;
1402 span
->array
->ChanType
= origChanType
;
1403 span
->array
->rgba
= origRgba
;
1408 * Read float RGBA pixels from a renderbuffer. Clipping will be done to
1409 * prevent reading ouside the buffer's boundaries.
1410 * \param rgba the returned colors
1413 _swrast_read_rgba_span( struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1414 GLuint n
, GLint x
, GLint y
,
1417 struct swrast_renderbuffer
*srb
= swrast_renderbuffer(rb
);
1418 GLenum dstType
= GL_FLOAT
;
1419 const GLint bufWidth
= (GLint
) rb
->Width
;
1420 const GLint bufHeight
= (GLint
) rb
->Height
;
1422 if (y
< 0 || y
>= bufHeight
|| x
+ (GLint
) n
< 0 || x
>= bufWidth
) {
1423 /* completely above, below, or right */
1424 /* XXX maybe leave rgba values undefined? */
1425 memset(rgba
, 0, 4 * n
* sizeof(GLchan
));
1432 /* left edge clipping */
1434 length
= (GLint
) n
- skip
;
1436 /* completely left of window */
1439 if (length
> bufWidth
) {
1443 else if ((GLint
) (x
+ n
) > bufWidth
) {
1444 /* right edge clipping */
1446 length
= bufWidth
- x
;
1448 /* completely to right of window */
1459 ASSERT(rb
->_BaseFormat
== GL_RGBA
||
1460 rb
->_BaseFormat
== GL_RGB
||
1461 rb
->_BaseFormat
== GL_RG
||
1462 rb
->_BaseFormat
== GL_RED
||
1463 rb
->_BaseFormat
== GL_LUMINANCE
||
1464 rb
->_BaseFormat
== GL_INTENSITY
||
1465 rb
->_BaseFormat
== GL_LUMINANCE_ALPHA
||
1466 rb
->_BaseFormat
== GL_ALPHA
);
1470 src
= _swrast_pixel_address(rb
, x
+ skip
, y
);
1472 if (dstType
== GL_UNSIGNED_BYTE
) {
1473 _mesa_unpack_ubyte_rgba_row(rb
->Format
, length
, src
,
1474 (GLubyte (*)[4]) rgba
+ skip
);
1476 else if (dstType
== GL_FLOAT
) {
1477 _mesa_unpack_rgba_row(rb
->Format
, length
, src
,
1478 (GLfloat (*)[4]) rgba
+ skip
);
1481 _mesa_problem(ctx
, "unexpected type in _swrast_read_rgba_span()");
1488 * Get colors at x/y positions with clipping.
1489 * \param type type of values to return
1492 get_values(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1493 GLuint count
, const GLint x
[], const GLint y
[],
1494 void *values
, GLenum type
)
1498 for (i
= 0; i
< count
; i
++) {
1499 if (x
[i
] >= 0 && y
[i
] >= 0 &&
1500 x
[i
] < (GLint
) rb
->Width
&& y
[i
] < (GLint
) rb
->Height
) {
1502 const GLubyte
*src
= _swrast_pixel_address(rb
, x
[i
], y
[i
]);
1504 if (type
== GL_UNSIGNED_BYTE
) {
1505 _mesa_unpack_ubyte_rgba_row(rb
->Format
, 1, src
,
1506 (GLubyte (*)[4]) values
+ i
);
1508 else if (type
== GL_FLOAT
) {
1509 _mesa_unpack_rgba_row(rb
->Format
, 1, src
,
1510 (GLfloat (*)[4]) values
+ i
);
1513 _mesa_problem(ctx
, "unexpected type in get_values()");
1521 * Get row of colors with clipping.
1522 * \param type type of values to return
1525 get_row(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1526 GLuint count
, GLint x
, GLint y
,
1527 GLvoid
*values
, GLenum type
)
1532 if (y
< 0 || y
>= (GLint
) rb
->Height
)
1533 return; /* above or below */
1535 if (x
+ (GLint
) count
<= 0 || x
>= (GLint
) rb
->Width
)
1536 return; /* entirely left or right */
1538 if (x
+ count
> rb
->Width
) {
1540 GLint clip
= x
+ count
- rb
->Width
;
1551 src
= _swrast_pixel_address(rb
, x
, y
);
1553 if (type
== GL_UNSIGNED_BYTE
) {
1554 _mesa_unpack_ubyte_rgba_row(rb
->Format
, count
, src
,
1555 (GLubyte (*)[4]) values
+ skip
);
1557 else if (type
== GL_FLOAT
) {
1558 _mesa_unpack_rgba_row(rb
->Format
, count
, src
,
1559 (GLfloat (*)[4]) values
+ skip
);
1562 _mesa_problem(ctx
, "unexpected type in get_row()");
1568 * Get RGBA pixels from the given renderbuffer.
1569 * Used by blending, logicop and masking functions.
1570 * \return pointer to the colors we read.
1573 _swrast_get_dest_rgba(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1578 /* Point rbPixels to a temporary space */
1579 rbPixels
= span
->array
->attribs
[FRAG_ATTRIB_MAX
- 1];
1581 /* Get destination values from renderbuffer */
1582 if (span
->arrayMask
& SPAN_XY
) {
1583 get_values(ctx
, rb
, span
->end
, span
->array
->x
, span
->array
->y
,
1584 rbPixels
, span
->array
->ChanType
);
1587 get_row(ctx
, rb
, span
->end
, span
->x
, span
->y
,
1588 rbPixels
, span
->array
->ChanType
);