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"
55 * Set default fragment attributes for the span using the
56 * current raster values. Used prior to glDraw/CopyPixels
60 _swrast_span_default_attribs(struct gl_context
*ctx
, SWspan
*span
)
65 const GLfloat depthMax
= ctx
->DrawBuffer
->_DepthMaxF
;
66 if (ctx
->DrawBuffer
->Visual
.depthBits
<= 16)
67 span
->z
= FloatToFixed(ctx
->Current
.RasterPos
[2] * depthMax
+ 0.5F
);
69 GLfloat tmpf
= ctx
->Current
.RasterPos
[2] * depthMax
;
70 tmpf
= MIN2(tmpf
, depthMax
);
71 span
->z
= (GLint
)tmpf
;
74 span
->interpMask
|= SPAN_Z
;
77 /* W (for perspective correction) */
78 span
->attrStart
[FRAG_ATTRIB_WPOS
][3] = 1.0;
79 span
->attrStepX
[FRAG_ATTRIB_WPOS
][3] = 0.0;
80 span
->attrStepY
[FRAG_ATTRIB_WPOS
][3] = 0.0;
82 /* primary color, or color index */
83 UNCLAMPED_FLOAT_TO_CHAN(r
, ctx
->Current
.RasterColor
[0]);
84 UNCLAMPED_FLOAT_TO_CHAN(g
, ctx
->Current
.RasterColor
[1]);
85 UNCLAMPED_FLOAT_TO_CHAN(b
, ctx
->Current
.RasterColor
[2]);
86 UNCLAMPED_FLOAT_TO_CHAN(a
, ctx
->Current
.RasterColor
[3]);
87 #if CHAN_TYPE == GL_FLOAT
93 span
->red
= IntToFixed(r
);
94 span
->green
= IntToFixed(g
);
95 span
->blue
= IntToFixed(b
);
96 span
->alpha
= IntToFixed(a
);
102 span
->interpMask
|= SPAN_RGBA
;
104 COPY_4V(span
->attrStart
[FRAG_ATTRIB_COL0
], ctx
->Current
.RasterColor
);
105 ASSIGN_4V(span
->attrStepX
[FRAG_ATTRIB_COL0
], 0.0, 0.0, 0.0, 0.0);
106 ASSIGN_4V(span
->attrStepY
[FRAG_ATTRIB_COL0
], 0.0, 0.0, 0.0, 0.0);
108 /* Secondary color */
109 if (ctx
->Light
.Enabled
|| ctx
->Fog
.ColorSumEnabled
)
111 COPY_4V(span
->attrStart
[FRAG_ATTRIB_COL1
], ctx
->Current
.RasterSecondaryColor
);
112 ASSIGN_4V(span
->attrStepX
[FRAG_ATTRIB_COL1
], 0.0, 0.0, 0.0, 0.0);
113 ASSIGN_4V(span
->attrStepY
[FRAG_ATTRIB_COL1
], 0.0, 0.0, 0.0, 0.0);
118 const SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
119 GLfloat fogVal
; /* a coord or a blend factor */
120 if (swrast
->_PreferPixelFog
) {
121 /* fog blend factors will be computed from fog coordinates per pixel */
122 fogVal
= ctx
->Current
.RasterDistance
;
125 /* fog blend factor should be computed from fogcoord now */
126 fogVal
= _swrast_z_to_fogfactor(ctx
, ctx
->Current
.RasterDistance
);
128 span
->attrStart
[FRAG_ATTRIB_FOGC
][0] = fogVal
;
129 span
->attrStepX
[FRAG_ATTRIB_FOGC
][0] = 0.0;
130 span
->attrStepY
[FRAG_ATTRIB_FOGC
][0] = 0.0;
136 for (i
= 0; i
< ctx
->Const
.MaxTextureCoordUnits
; i
++) {
137 const GLuint attr
= FRAG_ATTRIB_TEX0
+ i
;
138 const GLfloat
*tc
= ctx
->Current
.RasterTexCoords
[i
];
139 if (ctx
->FragmentProgram
._Current
|| ctx
->ATIFragmentShader
._Enabled
) {
140 COPY_4V(span
->attrStart
[attr
], tc
);
142 else if (tc
[3] > 0.0F
) {
143 /* use (s/q, t/q, r/q, 1) */
144 span
->attrStart
[attr
][0] = tc
[0] / tc
[3];
145 span
->attrStart
[attr
][1] = tc
[1] / tc
[3];
146 span
->attrStart
[attr
][2] = tc
[2] / tc
[3];
147 span
->attrStart
[attr
][3] = 1.0;
150 ASSIGN_4V(span
->attrStart
[attr
], 0.0F
, 0.0F
, 0.0F
, 1.0F
);
152 ASSIGN_4V(span
->attrStepX
[attr
], 0.0F
, 0.0F
, 0.0F
, 0.0F
);
153 ASSIGN_4V(span
->attrStepY
[attr
], 0.0F
, 0.0F
, 0.0F
, 0.0F
);
160 * Interpolate the active attributes (and'd with attrMask) to
161 * fill in span->array->attribs[].
162 * Perspective correction will be done. The point/line/triangle function
163 * should have computed attrStart/Step values for FRAG_ATTRIB_WPOS[3]!
166 interpolate_active_attribs(struct gl_context
*ctx
, SWspan
*span
, GLbitfield attrMask
)
168 const SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
171 * Don't overwrite existing array values, such as colors that may have
172 * been produced by glDraw/CopyPixels.
174 attrMask
&= ~span
->arrayAttribs
;
177 if (attrMask
& (1 << attr
)) {
178 const GLfloat dwdx
= span
->attrStepX
[FRAG_ATTRIB_WPOS
][3];
179 GLfloat w
= span
->attrStart
[FRAG_ATTRIB_WPOS
][3];
180 const GLfloat dv0dx
= span
->attrStepX
[attr
][0];
181 const GLfloat dv1dx
= span
->attrStepX
[attr
][1];
182 const GLfloat dv2dx
= span
->attrStepX
[attr
][2];
183 const GLfloat dv3dx
= span
->attrStepX
[attr
][3];
184 GLfloat v0
= span
->attrStart
[attr
][0] + span
->leftClip
* dv0dx
;
185 GLfloat v1
= span
->attrStart
[attr
][1] + span
->leftClip
* dv1dx
;
186 GLfloat v2
= span
->attrStart
[attr
][2] + span
->leftClip
* dv2dx
;
187 GLfloat v3
= span
->attrStart
[attr
][3] + span
->leftClip
* dv3dx
;
189 for (k
= 0; k
< span
->end
; k
++) {
190 const GLfloat invW
= 1.0f
/ w
;
191 span
->array
->attribs
[attr
][k
][0] = v0
* invW
;
192 span
->array
->attribs
[attr
][k
][1] = v1
* invW
;
193 span
->array
->attribs
[attr
][k
][2] = v2
* invW
;
194 span
->array
->attribs
[attr
][k
][3] = v3
* invW
;
201 ASSERT((span
->arrayAttribs
& (1 << attr
)) == 0);
202 span
->arrayAttribs
|= (1 << attr
);
209 * Interpolate primary colors to fill in the span->array->rgba8 (or rgb16)
213 interpolate_int_colors(struct gl_context
*ctx
, SWspan
*span
)
215 const GLuint n
= span
->end
;
219 ASSERT(!(span
->arrayMask
& SPAN_RGBA
));
222 switch (span
->array
->ChanType
) {
224 case GL_UNSIGNED_BYTE
:
226 GLubyte (*rgba
)[4] = span
->array
->rgba8
;
227 if (span
->interpMask
& SPAN_FLAT
) {
229 color
[RCOMP
] = FixedToInt(span
->red
);
230 color
[GCOMP
] = FixedToInt(span
->green
);
231 color
[BCOMP
] = FixedToInt(span
->blue
);
232 color
[ACOMP
] = FixedToInt(span
->alpha
);
233 for (i
= 0; i
< n
; i
++) {
234 COPY_4UBV(rgba
[i
], color
);
238 GLfixed r
= span
->red
;
239 GLfixed g
= span
->green
;
240 GLfixed b
= span
->blue
;
241 GLfixed a
= span
->alpha
;
242 GLint dr
= span
->redStep
;
243 GLint dg
= span
->greenStep
;
244 GLint db
= span
->blueStep
;
245 GLint da
= span
->alphaStep
;
246 for (i
= 0; i
< n
; i
++) {
247 rgba
[i
][RCOMP
] = FixedToChan(r
);
248 rgba
[i
][GCOMP
] = FixedToChan(g
);
249 rgba
[i
][BCOMP
] = FixedToChan(b
);
250 rgba
[i
][ACOMP
] = FixedToChan(a
);
259 case GL_UNSIGNED_SHORT
:
261 GLushort (*rgba
)[4] = span
->array
->rgba16
;
262 if (span
->interpMask
& SPAN_FLAT
) {
264 color
[RCOMP
] = FixedToInt(span
->red
);
265 color
[GCOMP
] = FixedToInt(span
->green
);
266 color
[BCOMP
] = FixedToInt(span
->blue
);
267 color
[ACOMP
] = FixedToInt(span
->alpha
);
268 for (i
= 0; i
< n
; i
++) {
269 COPY_4V(rgba
[i
], color
);
273 GLushort (*rgba
)[4] = span
->array
->rgba16
;
275 GLint dr
, dg
, db
, da
;
281 dg
= span
->greenStep
;
283 da
= span
->alphaStep
;
284 for (i
= 0; i
< n
; i
++) {
285 rgba
[i
][RCOMP
] = FixedToChan(r
);
286 rgba
[i
][GCOMP
] = FixedToChan(g
);
287 rgba
[i
][BCOMP
] = FixedToChan(b
);
288 rgba
[i
][ACOMP
] = FixedToChan(a
);
299 interpolate_active_attribs(ctx
, span
, FRAG_BIT_COL0
);
302 _mesa_problem(ctx
, "bad datatype 0x%x in interpolate_int_colors",
303 span
->array
->ChanType
);
305 span
->arrayMask
|= SPAN_RGBA
;
310 * Populate the FRAG_ATTRIB_COL0 array.
313 interpolate_float_colors(SWspan
*span
)
315 GLfloat (*col0
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL0
];
316 const GLuint n
= span
->end
;
319 assert(!(span
->arrayAttribs
& FRAG_BIT_COL0
));
321 if (span
->arrayMask
& SPAN_RGBA
) {
322 /* convert array of int colors */
323 for (i
= 0; i
< n
; i
++) {
324 col0
[i
][0] = UBYTE_TO_FLOAT(span
->array
->rgba8
[i
][0]);
325 col0
[i
][1] = UBYTE_TO_FLOAT(span
->array
->rgba8
[i
][1]);
326 col0
[i
][2] = UBYTE_TO_FLOAT(span
->array
->rgba8
[i
][2]);
327 col0
[i
][3] = UBYTE_TO_FLOAT(span
->array
->rgba8
[i
][3]);
331 /* interpolate red/green/blue/alpha to get float colors */
332 ASSERT(span
->interpMask
& SPAN_RGBA
);
333 if (span
->interpMask
& SPAN_FLAT
) {
334 GLfloat r
= FixedToFloat(span
->red
);
335 GLfloat g
= FixedToFloat(span
->green
);
336 GLfloat b
= FixedToFloat(span
->blue
);
337 GLfloat a
= FixedToFloat(span
->alpha
);
338 for (i
= 0; i
< n
; i
++) {
339 ASSIGN_4V(col0
[i
], r
, g
, b
, a
);
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 GLfloat dr
= FixedToFloat(span
->redStep
);
348 GLfloat dg
= FixedToFloat(span
->greenStep
);
349 GLfloat db
= FixedToFloat(span
->blueStep
);
350 GLfloat da
= FixedToFloat(span
->alphaStep
);
351 for (i
= 0; i
< n
; i
++) {
364 span
->arrayAttribs
|= FRAG_BIT_COL0
;
365 span
->array
->ChanType
= GL_FLOAT
;
371 * Fill in the span.zArray array from the span->z, zStep values.
374 _swrast_span_interpolate_z( const struct gl_context
*ctx
, SWspan
*span
)
376 const GLuint n
= span
->end
;
379 ASSERT(!(span
->arrayMask
& SPAN_Z
));
381 if (ctx
->DrawBuffer
->Visual
.depthBits
<= 16) {
382 GLfixed zval
= span
->z
;
383 GLuint
*z
= span
->array
->z
;
384 for (i
= 0; i
< n
; i
++) {
385 z
[i
] = FixedToInt(zval
);
390 /* Deep Z buffer, no fixed->int shift */
391 GLuint zval
= span
->z
;
392 GLuint
*z
= span
->array
->z
;
393 for (i
= 0; i
< n
; i
++) {
398 span
->interpMask
&= ~SPAN_Z
;
399 span
->arrayMask
|= SPAN_Z
;
404 * Compute mipmap LOD from partial derivatives.
405 * This the ideal solution, as given in the OpenGL spec.
408 _swrast_compute_lambda(GLfloat dsdx
, GLfloat dsdy
, GLfloat dtdx
, GLfloat dtdy
,
409 GLfloat dqdx
, GLfloat dqdy
, GLfloat texW
, GLfloat texH
,
410 GLfloat s
, GLfloat t
, GLfloat q
, GLfloat invQ
)
412 GLfloat dudx
= texW
* ((s
+ dsdx
) / (q
+ dqdx
) - s
* invQ
);
413 GLfloat dvdx
= texH
* ((t
+ dtdx
) / (q
+ dqdx
) - t
* invQ
);
414 GLfloat dudy
= texW
* ((s
+ dsdy
) / (q
+ dqdy
) - s
* invQ
);
415 GLfloat dvdy
= texH
* ((t
+ dtdy
) / (q
+ dqdy
) - t
* invQ
);
416 GLfloat x
= SQRTF(dudx
* dudx
+ dvdx
* dvdx
);
417 GLfloat y
= SQRTF(dudy
* dudy
+ dvdy
* dvdy
);
418 GLfloat rho
= MAX2(x
, y
);
419 GLfloat lambda
= LOG2(rho
);
425 * Compute mipmap LOD from partial derivatives.
426 * This is a faster approximation than above function.
430 _swrast_compute_lambda(GLfloat dsdx
, GLfloat dsdy
, GLfloat dtdx
, GLfloat dtdy
,
431 GLfloat dqdx
, GLfloat dqdy
, GLfloat texW
, GLfloat texH
,
432 GLfloat s
, GLfloat t
, GLfloat q
, GLfloat invQ
)
434 GLfloat dsdx2
= (s
+ dsdx
) / (q
+ dqdx
) - s
* invQ
;
435 GLfloat dtdx2
= (t
+ dtdx
) / (q
+ dqdx
) - t
* invQ
;
436 GLfloat dsdy2
= (s
+ dsdy
) / (q
+ dqdy
) - s
* invQ
;
437 GLfloat dtdy2
= (t
+ dtdy
) / (q
+ dqdy
) - t
* invQ
;
438 GLfloat maxU
, maxV
, rho
, lambda
;
439 dsdx2
= FABSF(dsdx2
);
440 dsdy2
= FABSF(dsdy2
);
441 dtdx2
= FABSF(dtdx2
);
442 dtdy2
= FABSF(dtdy2
);
443 maxU
= MAX2(dsdx2
, dsdy2
) * texW
;
444 maxV
= MAX2(dtdx2
, dtdy2
) * texH
;
445 rho
= MAX2(maxU
, maxV
);
453 * Fill in the span.array->attrib[FRAG_ATTRIB_TEXn] arrays from the
454 * using the attrStart/Step values.
456 * This function only used during fixed-function fragment processing.
458 * Note: in the places where we divide by Q (or mult by invQ) we're
459 * really doing two things: perspective correction and texcoord
460 * projection. Remember, for texcoord (s,t,r,q) we need to index
461 * texels with (s/q, t/q, r/q).
464 interpolate_texcoords(struct gl_context
*ctx
, SWspan
*span
)
467 = (ctx
->Texture
._EnabledCoordUnits
> 1) ? ctx
->Const
.MaxTextureUnits
: 1;
470 /* XXX CoordUnits vs. ImageUnits */
471 for (u
= 0; u
< maxUnit
; u
++) {
472 if (ctx
->Texture
._EnabledCoordUnits
& (1 << u
)) {
473 const GLuint attr
= FRAG_ATTRIB_TEX0
+ u
;
474 const struct gl_texture_object
*obj
= ctx
->Texture
.Unit
[u
]._Current
;
476 GLboolean needLambda
;
477 GLfloat (*texcoord
)[4] = span
->array
->attribs
[attr
];
478 GLfloat
*lambda
= span
->array
->lambda
[u
];
479 const GLfloat dsdx
= span
->attrStepX
[attr
][0];
480 const GLfloat dsdy
= span
->attrStepY
[attr
][0];
481 const GLfloat dtdx
= span
->attrStepX
[attr
][1];
482 const GLfloat dtdy
= span
->attrStepY
[attr
][1];
483 const GLfloat drdx
= span
->attrStepX
[attr
][2];
484 const GLfloat dqdx
= span
->attrStepX
[attr
][3];
485 const GLfloat dqdy
= span
->attrStepY
[attr
][3];
486 GLfloat s
= span
->attrStart
[attr
][0] + span
->leftClip
* dsdx
;
487 GLfloat t
= span
->attrStart
[attr
][1] + span
->leftClip
* dtdx
;
488 GLfloat r
= span
->attrStart
[attr
][2] + span
->leftClip
* drdx
;
489 GLfloat q
= span
->attrStart
[attr
][3] + span
->leftClip
* dqdx
;
492 const struct gl_texture_image
*img
= obj
->Image
[0][obj
->BaseLevel
];
493 needLambda
= (obj
->Sampler
.MinFilter
!= obj
->Sampler
.MagFilter
)
494 || ctx
->FragmentProgram
._Current
;
495 /* LOD is calculated directly in the ansiotropic filter, we can
496 * skip the normal lambda function as the result is ignored.
498 if (obj
->Sampler
.MaxAnisotropy
> 1.0 &&
499 obj
->Sampler
.MinFilter
== GL_LINEAR_MIPMAP_LINEAR
) {
500 needLambda
= GL_FALSE
;
502 texW
= img
->WidthScale
;
503 texH
= img
->HeightScale
;
506 /* using a fragment program */
509 needLambda
= GL_FALSE
;
514 if (ctx
->FragmentProgram
._Current
515 || ctx
->ATIFragmentShader
._Enabled
) {
516 /* do perspective correction but don't divide s, t, r by q */
517 const GLfloat dwdx
= span
->attrStepX
[FRAG_ATTRIB_WPOS
][3];
518 GLfloat w
= span
->attrStart
[FRAG_ATTRIB_WPOS
][3] + span
->leftClip
* dwdx
;
519 for (i
= 0; i
< span
->end
; i
++) {
520 const GLfloat invW
= 1.0F
/ w
;
521 texcoord
[i
][0] = s
* invW
;
522 texcoord
[i
][1] = t
* invW
;
523 texcoord
[i
][2] = r
* invW
;
524 texcoord
[i
][3] = q
* invW
;
525 lambda
[i
] = _swrast_compute_lambda(dsdx
, dsdy
, dtdx
, dtdy
,
526 dqdx
, dqdy
, texW
, texH
,
536 for (i
= 0; i
< span
->end
; i
++) {
537 const GLfloat invQ
= (q
== 0.0F
) ? 1.0F
: (1.0F
/ q
);
538 texcoord
[i
][0] = s
* invQ
;
539 texcoord
[i
][1] = t
* invQ
;
540 texcoord
[i
][2] = r
* invQ
;
542 lambda
[i
] = _swrast_compute_lambda(dsdx
, dsdy
, dtdx
, dtdy
,
543 dqdx
, dqdy
, texW
, texH
,
551 span
->arrayMask
|= SPAN_LAMBDA
;
555 if (ctx
->FragmentProgram
._Current
||
556 ctx
->ATIFragmentShader
._Enabled
) {
557 /* do perspective correction but don't divide s, t, r by q */
558 const GLfloat dwdx
= span
->attrStepX
[FRAG_ATTRIB_WPOS
][3];
559 GLfloat w
= span
->attrStart
[FRAG_ATTRIB_WPOS
][3] + span
->leftClip
* dwdx
;
560 for (i
= 0; i
< span
->end
; i
++) {
561 const GLfloat invW
= 1.0F
/ w
;
562 texcoord
[i
][0] = s
* invW
;
563 texcoord
[i
][1] = t
* invW
;
564 texcoord
[i
][2] = r
* invW
;
565 texcoord
[i
][3] = q
* invW
;
574 else if (dqdx
== 0.0F
) {
575 /* Ortho projection or polygon's parallel to window X axis */
576 const GLfloat invQ
= (q
== 0.0F
) ? 1.0F
: (1.0F
/ q
);
577 for (i
= 0; i
< span
->end
; i
++) {
578 texcoord
[i
][0] = s
* invQ
;
579 texcoord
[i
][1] = t
* invQ
;
580 texcoord
[i
][2] = r
* invQ
;
589 for (i
= 0; i
< span
->end
; i
++) {
590 const GLfloat invQ
= (q
== 0.0F
) ? 1.0F
: (1.0F
/ q
);
591 texcoord
[i
][0] = s
* invQ
;
592 texcoord
[i
][1] = t
* invQ
;
593 texcoord
[i
][2] = r
* invQ
;
609 * Fill in the arrays->attribs[FRAG_ATTRIB_WPOS] array.
612 interpolate_wpos(struct gl_context
*ctx
, SWspan
*span
)
614 GLfloat (*wpos
)[4] = span
->array
->attribs
[FRAG_ATTRIB_WPOS
];
616 const GLfloat zScale
= 1.0F
/ ctx
->DrawBuffer
->_DepthMaxF
;
619 if (span
->arrayMask
& SPAN_XY
) {
620 for (i
= 0; i
< span
->end
; i
++) {
621 wpos
[i
][0] = (GLfloat
) span
->array
->x
[i
];
622 wpos
[i
][1] = (GLfloat
) span
->array
->y
[i
];
626 for (i
= 0; i
< span
->end
; i
++) {
627 wpos
[i
][0] = (GLfloat
) span
->x
+ i
;
628 wpos
[i
][1] = (GLfloat
) span
->y
;
632 dw
= span
->attrStepX
[FRAG_ATTRIB_WPOS
][3];
633 w
= span
->attrStart
[FRAG_ATTRIB_WPOS
][3] + span
->leftClip
* dw
;
634 for (i
= 0; i
< span
->end
; i
++) {
635 wpos
[i
][2] = (GLfloat
) span
->array
->z
[i
] * zScale
;
643 * Apply the current polygon stipple pattern to a span of pixels.
646 stipple_polygon_span(struct gl_context
*ctx
, SWspan
*span
)
648 GLubyte
*mask
= span
->array
->mask
;
650 ASSERT(ctx
->Polygon
.StippleFlag
);
652 if (span
->arrayMask
& SPAN_XY
) {
653 /* arrays of x/y pixel coords */
655 for (i
= 0; i
< span
->end
; i
++) {
656 const GLint col
= span
->array
->x
[i
] % 32;
657 const GLint row
= span
->array
->y
[i
] % 32;
658 const GLuint stipple
= ctx
->PolygonStipple
[row
];
659 if (((1 << col
) & stipple
) == 0) {
665 /* horizontal span of pixels */
666 const GLuint highBit
= 1 << 31;
667 const GLuint stipple
= ctx
->PolygonStipple
[span
->y
% 32];
668 GLuint i
, m
= highBit
>> (GLuint
) (span
->x
% 32);
669 for (i
= 0; i
< span
->end
; i
++) {
670 if ((m
& stipple
) == 0) {
679 span
->writeAll
= GL_FALSE
;
684 * Clip a pixel span to the current buffer/window boundaries:
685 * DrawBuffer->_Xmin, _Xmax, _Ymin, _Ymax. This will accomplish
686 * window clipping and scissoring.
687 * Return: GL_TRUE some pixels still visible
688 * GL_FALSE nothing visible
691 clip_span( struct gl_context
*ctx
, SWspan
*span
)
693 const GLint xmin
= ctx
->DrawBuffer
->_Xmin
;
694 const GLint xmax
= ctx
->DrawBuffer
->_Xmax
;
695 const GLint ymin
= ctx
->DrawBuffer
->_Ymin
;
696 const GLint ymax
= ctx
->DrawBuffer
->_Ymax
;
700 if (span
->arrayMask
& SPAN_XY
) {
701 /* arrays of x/y pixel coords */
702 const GLint
*x
= span
->array
->x
;
703 const GLint
*y
= span
->array
->y
;
704 const GLint n
= span
->end
;
705 GLubyte
*mask
= span
->array
->mask
;
707 if (span
->arrayMask
& SPAN_MASK
) {
708 /* note: using & intead of && to reduce branches */
709 for (i
= 0; i
< n
; i
++) {
710 mask
[i
] &= (x
[i
] >= xmin
) & (x
[i
] < xmax
)
711 & (y
[i
] >= ymin
) & (y
[i
] < ymax
);
715 /* note: using & intead of && to reduce branches */
716 for (i
= 0; i
< n
; i
++) {
717 mask
[i
] = (x
[i
] >= xmin
) & (x
[i
] < xmax
)
718 & (y
[i
] >= ymin
) & (y
[i
] < ymax
);
721 return GL_TRUE
; /* some pixels visible */
724 /* horizontal span of pixels */
725 const GLint x
= span
->x
;
726 const GLint y
= span
->y
;
729 /* Trivial rejection tests */
730 if (y
< ymin
|| y
>= ymax
|| x
+ n
<= xmin
|| x
>= xmax
) {
732 return GL_FALSE
; /* all pixels clipped */
738 n
= span
->end
= xmax
- x
;
741 /* Clip to the left */
743 const GLint leftClip
= xmin
- x
;
746 ASSERT(leftClip
> 0);
747 ASSERT(x
+ n
> xmin
);
749 /* Clip 'leftClip' pixels from the left side.
750 * The span->leftClip field will be applied when we interpolate
751 * fragment attributes.
752 * For arrays of values, shift them left.
754 for (i
= 0; i
< FRAG_ATTRIB_MAX
; i
++) {
755 if (span
->interpMask
& (1 << i
)) {
757 for (j
= 0; j
< 4; j
++) {
758 span
->attrStart
[i
][j
] += leftClip
* span
->attrStepX
[i
][j
];
763 span
->red
+= leftClip
* span
->redStep
;
764 span
->green
+= leftClip
* span
->greenStep
;
765 span
->blue
+= leftClip
* span
->blueStep
;
766 span
->alpha
+= leftClip
* span
->alphaStep
;
767 span
->index
+= leftClip
* span
->indexStep
;
768 span
->z
+= leftClip
* span
->zStep
;
769 span
->intTex
[0] += leftClip
* span
->intTexStep
[0];
770 span
->intTex
[1] += leftClip
* span
->intTexStep
[1];
772 #define SHIFT_ARRAY(ARRAY, SHIFT, LEN) \
773 memcpy(ARRAY, ARRAY + (SHIFT), (LEN) * sizeof(ARRAY[0]))
775 for (i
= 0; i
< FRAG_ATTRIB_MAX
; i
++) {
776 if (span
->arrayAttribs
& (1 << i
)) {
777 /* shift array elements left by 'leftClip' */
778 SHIFT_ARRAY(span
->array
->attribs
[i
], leftClip
, n
- leftClip
);
782 SHIFT_ARRAY(span
->array
->mask
, leftClip
, n
- leftClip
);
783 SHIFT_ARRAY(span
->array
->rgba8
, leftClip
, n
- leftClip
);
784 SHIFT_ARRAY(span
->array
->rgba16
, leftClip
, n
- leftClip
);
785 SHIFT_ARRAY(span
->array
->x
, leftClip
, n
- leftClip
);
786 SHIFT_ARRAY(span
->array
->y
, leftClip
, n
- leftClip
);
787 SHIFT_ARRAY(span
->array
->z
, leftClip
, n
- leftClip
);
788 SHIFT_ARRAY(span
->array
->index
, leftClip
, n
- leftClip
);
789 for (i
= 0; i
< MAX_TEXTURE_COORD_UNITS
; i
++) {
790 SHIFT_ARRAY(span
->array
->lambda
[i
], leftClip
, n
- leftClip
);
792 SHIFT_ARRAY(span
->array
->coverage
, leftClip
, n
- leftClip
);
796 span
->leftClip
= leftClip
;
798 span
->end
-= leftClip
;
799 span
->writeAll
= GL_FALSE
;
802 ASSERT(span
->x
>= xmin
);
803 ASSERT(span
->x
+ span
->end
<= xmax
);
804 ASSERT(span
->y
>= ymin
);
805 ASSERT(span
->y
< ymax
);
807 return GL_TRUE
; /* some pixels visible */
813 * Add specular colors to primary colors.
814 * Only called during fixed-function operation.
815 * Result is float color array (FRAG_ATTRIB_COL0).
818 add_specular(struct gl_context
*ctx
, SWspan
*span
)
820 const SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
821 const GLubyte
*mask
= span
->array
->mask
;
822 GLfloat (*col0
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL0
];
823 GLfloat (*col1
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL1
];
826 ASSERT(!ctx
->FragmentProgram
._Current
);
827 ASSERT(span
->arrayMask
& SPAN_RGBA
);
828 ASSERT(swrast
->_ActiveAttribMask
& FRAG_BIT_COL1
);
829 (void) swrast
; /* silence warning */
831 if (span
->array
->ChanType
== GL_FLOAT
) {
832 if ((span
->arrayAttribs
& FRAG_BIT_COL0
) == 0) {
833 interpolate_active_attribs(ctx
, span
, FRAG_BIT_COL0
);
837 /* need float colors */
838 if ((span
->arrayAttribs
& FRAG_BIT_COL0
) == 0) {
839 interpolate_float_colors(span
);
843 if ((span
->arrayAttribs
& FRAG_BIT_COL1
) == 0) {
844 /* XXX could avoid this and interpolate COL1 in the loop below */
845 interpolate_active_attribs(ctx
, span
, FRAG_BIT_COL1
);
848 ASSERT(span
->arrayAttribs
& FRAG_BIT_COL0
);
849 ASSERT(span
->arrayAttribs
& FRAG_BIT_COL1
);
851 for (i
= 0; i
< span
->end
; i
++) {
853 col0
[i
][0] += col1
[i
][0];
854 col0
[i
][1] += col1
[i
][1];
855 col0
[i
][2] += col1
[i
][2];
859 span
->array
->ChanType
= GL_FLOAT
;
864 * Apply antialiasing coverage value to alpha values.
867 apply_aa_coverage(SWspan
*span
)
869 const GLfloat
*coverage
= span
->array
->coverage
;
871 if (span
->array
->ChanType
== GL_UNSIGNED_BYTE
) {
872 GLubyte (*rgba
)[4] = span
->array
->rgba8
;
873 for (i
= 0; i
< span
->end
; i
++) {
874 const GLfloat a
= rgba
[i
][ACOMP
] * coverage
[i
];
875 rgba
[i
][ACOMP
] = (GLubyte
) CLAMP(a
, 0.0, 255.0);
876 ASSERT(coverage
[i
] >= 0.0);
877 ASSERT(coverage
[i
] <= 1.0);
880 else if (span
->array
->ChanType
== GL_UNSIGNED_SHORT
) {
881 GLushort (*rgba
)[4] = span
->array
->rgba16
;
882 for (i
= 0; i
< span
->end
; i
++) {
883 const GLfloat a
= rgba
[i
][ACOMP
] * coverage
[i
];
884 rgba
[i
][ACOMP
] = (GLushort
) CLAMP(a
, 0.0, 65535.0);
888 GLfloat (*rgba
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL0
];
889 for (i
= 0; i
< span
->end
; i
++) {
890 rgba
[i
][ACOMP
] = rgba
[i
][ACOMP
] * coverage
[i
];
898 * Clamp span's float colors to [0,1]
901 clamp_colors(SWspan
*span
)
903 GLfloat (*rgba
)[4] = span
->array
->attribs
[FRAG_ATTRIB_COL0
];
905 ASSERT(span
->array
->ChanType
== GL_FLOAT
);
906 for (i
= 0; i
< span
->end
; i
++) {
907 rgba
[i
][RCOMP
] = CLAMP(rgba
[i
][RCOMP
], 0.0F
, 1.0F
);
908 rgba
[i
][GCOMP
] = CLAMP(rgba
[i
][GCOMP
], 0.0F
, 1.0F
);
909 rgba
[i
][BCOMP
] = CLAMP(rgba
[i
][BCOMP
], 0.0F
, 1.0F
);
910 rgba
[i
][ACOMP
] = CLAMP(rgba
[i
][ACOMP
], 0.0F
, 1.0F
);
916 * Convert the span's color arrays to the given type.
917 * The only way 'output' can be greater than zero is when we have a fragment
918 * program that writes to gl_FragData[1] or higher.
919 * \param output which fragment program color output is being processed
922 convert_color_type(SWspan
*span
, GLenum newType
, GLuint output
)
926 if (output
> 0 || span
->array
->ChanType
== GL_FLOAT
) {
927 src
= span
->array
->attribs
[FRAG_ATTRIB_COL0
+ output
];
928 span
->array
->ChanType
= GL_FLOAT
;
930 else if (span
->array
->ChanType
== GL_UNSIGNED_BYTE
) {
931 src
= span
->array
->rgba8
;
934 ASSERT(span
->array
->ChanType
== GL_UNSIGNED_SHORT
);
935 src
= span
->array
->rgba16
;
938 if (newType
== GL_UNSIGNED_BYTE
) {
939 dst
= span
->array
->rgba8
;
941 else if (newType
== GL_UNSIGNED_SHORT
) {
942 dst
= span
->array
->rgba16
;
945 dst
= span
->array
->attribs
[FRAG_ATTRIB_COL0
];
948 _mesa_convert_colors(span
->array
->ChanType
, src
,
950 span
->end
, span
->array
->mask
);
952 span
->array
->ChanType
= newType
;
953 span
->array
->rgba
= dst
;
959 * Apply fragment shader, fragment program or normal texturing to span.
962 shade_texture_span(struct gl_context
*ctx
, SWspan
*span
)
964 GLbitfield inputsRead
;
966 /* Determine which fragment attributes are actually needed */
967 if (ctx
->FragmentProgram
._Current
) {
968 inputsRead
= ctx
->FragmentProgram
._Current
->Base
.InputsRead
;
971 /* XXX we could be a bit smarter about this */
975 if (ctx
->FragmentProgram
._Current
||
976 ctx
->ATIFragmentShader
._Enabled
) {
977 /* programmable shading */
978 if (span
->primitive
== GL_BITMAP
&& span
->array
->ChanType
!= GL_FLOAT
) {
979 convert_color_type(span
, GL_FLOAT
, 0);
982 span
->array
->rgba
= (void *) span
->array
->attribs
[FRAG_ATTRIB_COL0
];
985 if (span
->primitive
!= GL_POINT
||
986 (span
->interpMask
& SPAN_RGBA
) ||
987 ctx
->Point
.PointSprite
) {
988 /* for single-pixel points, we populated the arrays already */
989 interpolate_active_attribs(ctx
, span
, ~0);
991 span
->array
->ChanType
= GL_FLOAT
;
993 if (!(span
->arrayMask
& SPAN_Z
))
994 _swrast_span_interpolate_z (ctx
, span
);
997 if (inputsRead
& FRAG_BIT_WPOS
)
999 /* XXX always interpolate wpos so that DDX/DDY work */
1001 interpolate_wpos(ctx
, span
);
1003 /* Run fragment program/shader now */
1004 if (ctx
->FragmentProgram
._Current
) {
1005 _swrast_exec_fragment_program(ctx
, span
);
1008 ASSERT(ctx
->ATIFragmentShader
._Enabled
);
1009 _swrast_exec_fragment_shader(ctx
, span
);
1012 else if (ctx
->Texture
._EnabledCoordUnits
) {
1013 /* conventional texturing */
1016 if ((span
->arrayAttribs
& FRAG_BIT_COL0
) == 0) {
1017 interpolate_int_colors(ctx
, span
);
1020 if (!(span
->arrayMask
& SPAN_RGBA
))
1021 interpolate_int_colors(ctx
, span
);
1023 if ((span
->arrayAttribs
& FRAG_BITS_TEX_ANY
) == 0x0)
1024 interpolate_texcoords(ctx
, span
);
1026 _swrast_texture_span(ctx
, span
);
1033 * Apply all the per-fragment operations to a span.
1034 * This now includes texturing (_swrast_write_texture_span() is history).
1035 * This function may modify any of the array values in the span.
1036 * span->interpMask and span->arrayMask may be changed but will be restored
1037 * to their original values before returning.
1040 _swrast_write_rgba_span( struct gl_context
*ctx
, SWspan
*span
)
1042 const SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
1043 const GLuint
*colorMask
= (GLuint
*) ctx
->Color
.ColorMask
;
1044 const GLbitfield origInterpMask
= span
->interpMask
;
1045 const GLbitfield origArrayMask
= span
->arrayMask
;
1046 const GLbitfield origArrayAttribs
= span
->arrayAttribs
;
1047 const GLenum origChanType
= span
->array
->ChanType
;
1048 void * const origRgba
= span
->array
->rgba
;
1049 const GLboolean shader
= (ctx
->FragmentProgram
._Current
1050 || ctx
->ATIFragmentShader
._Enabled
);
1051 const GLboolean shaderOrTexture
= shader
|| ctx
->Texture
._EnabledCoordUnits
;
1052 struct gl_framebuffer
*fb
= ctx
->DrawBuffer
;
1055 printf("%s() interp 0x%x array 0x%x\n", __FUNCTION__,
1056 span->interpMask, span->arrayMask);
1059 ASSERT(span
->primitive
== GL_POINT
||
1060 span
->primitive
== GL_LINE
||
1061 span
->primitive
== GL_POLYGON
||
1062 span
->primitive
== GL_BITMAP
);
1064 /* Fragment write masks */
1065 if (span
->arrayMask
& SPAN_MASK
) {
1066 /* mask was initialized by caller, probably glBitmap */
1067 span
->writeAll
= GL_FALSE
;
1070 memset(span
->array
->mask
, 1, span
->end
);
1071 span
->writeAll
= GL_TRUE
;
1074 /* Clip to window/scissor box */
1075 if (!clip_span(ctx
, span
)) {
1079 ASSERT(span
->end
<= MAX_WIDTH
);
1081 /* Depth bounds test */
1082 if (ctx
->Depth
.BoundsTest
&& fb
->Visual
.depthBits
> 0) {
1083 if (!_swrast_depth_bounds_test(ctx
, span
)) {
1089 /* Make sure all fragments are within window bounds */
1090 if (span
->arrayMask
& SPAN_XY
) {
1091 /* array of pixel locations */
1093 for (i
= 0; i
< span
->end
; i
++) {
1094 if (span
->array
->mask
[i
]) {
1095 assert(span
->array
->x
[i
] >= fb
->_Xmin
);
1096 assert(span
->array
->x
[i
] < fb
->_Xmax
);
1097 assert(span
->array
->y
[i
] >= fb
->_Ymin
);
1098 assert(span
->array
->y
[i
] < fb
->_Ymax
);
1104 /* Polygon Stippling */
1105 if (ctx
->Polygon
.StippleFlag
&& span
->primitive
== GL_POLYGON
) {
1106 stipple_polygon_span(ctx
, span
);
1109 /* This is the normal place to compute the fragment color/Z
1110 * from texturing or shading.
1112 if (shaderOrTexture
&& !swrast
->_DeferredTexture
) {
1113 shade_texture_span(ctx
, span
);
1116 /* Do the alpha test */
1117 if (ctx
->Color
.AlphaEnabled
) {
1118 if (!_swrast_alpha_test(ctx
, span
)) {
1119 /* all fragments failed test */
1124 /* Stencil and Z testing */
1125 if (ctx
->Stencil
._Enabled
|| ctx
->Depth
.Test
) {
1126 if (!(span
->arrayMask
& SPAN_Z
))
1127 _swrast_span_interpolate_z(ctx
, span
);
1129 if (ctx
->Transform
.DepthClamp
)
1130 _swrast_depth_clamp_span(ctx
, span
);
1132 if (ctx
->Stencil
._Enabled
) {
1133 /* Combined Z/stencil tests */
1134 if (!_swrast_stencil_and_ztest_span(ctx
, span
)) {
1135 /* all fragments failed test */
1139 else if (fb
->Visual
.depthBits
> 0) {
1140 /* Just regular depth testing */
1141 ASSERT(ctx
->Depth
.Test
);
1142 ASSERT(span
->arrayMask
& SPAN_Z
);
1143 if (!_swrast_depth_test_span(ctx
, span
)) {
1144 /* all fragments failed test */
1150 if (ctx
->Query
.CurrentOcclusionObject
) {
1151 /* update count of 'passed' fragments */
1152 struct gl_query_object
*q
= ctx
->Query
.CurrentOcclusionObject
;
1154 for (i
= 0; i
< span
->end
; i
++)
1155 q
->Result
+= span
->array
->mask
[i
];
1158 /* We had to wait until now to check for glColorMask(0,0,0,0) because of
1159 * the occlusion test.
1161 if (fb
->_NumColorDrawBuffers
== 1 && colorMask
[0] == 0x0) {
1162 /* no colors to write */
1166 /* If we were able to defer fragment color computation to now, there's
1167 * a good chance that many fragments will have already been killed by
1168 * Z/stencil testing.
1170 if (shaderOrTexture
&& swrast
->_DeferredTexture
) {
1171 shade_texture_span(ctx
, span
);
1175 if ((span
->arrayAttribs
& FRAG_BIT_COL0
) == 0) {
1176 interpolate_active_attribs(ctx
, span
, FRAG_BIT_COL0
);
1179 if ((span
->arrayMask
& SPAN_RGBA
) == 0) {
1180 interpolate_int_colors(ctx
, span
);
1184 ASSERT(span
->arrayMask
& SPAN_RGBA
);
1186 if (span
->primitive
== GL_BITMAP
|| !swrast
->SpecularVertexAdd
) {
1187 /* Add primary and specular (diffuse + specular) colors */
1189 if (ctx
->Fog
.ColorSumEnabled
||
1190 (ctx
->Light
.Enabled
&&
1191 ctx
->Light
.Model
.ColorControl
== GL_SEPARATE_SPECULAR_COLOR
)) {
1192 add_specular(ctx
, span
);
1198 if (swrast
->_FogEnabled
) {
1199 _swrast_fog_rgba_span(ctx
, span
);
1202 /* Antialias coverage application */
1203 if (span
->arrayMask
& SPAN_COVERAGE
) {
1204 apply_aa_coverage(span
);
1207 /* Clamp color/alpha values over the range [0.0, 1.0] before storage */
1208 if (ctx
->Color
.ClampFragmentColor
== GL_TRUE
&&
1209 span
->array
->ChanType
== GL_FLOAT
) {
1214 * Write to renderbuffers.
1215 * Depending on glDrawBuffer() state and the which color outputs are
1216 * written by the fragment shader, we may either replicate one color to
1217 * all renderbuffers or write a different color to each renderbuffer.
1218 * multiFragOutputs=TRUE for the later case.
1221 const GLuint numBuffers
= fb
->_NumColorDrawBuffers
;
1222 const struct gl_fragment_program
*fp
= ctx
->FragmentProgram
._Current
;
1223 const GLboolean multiFragOutputs
=
1224 (fp
&& fp
->Base
.OutputsWritten
>= (1 << FRAG_RESULT_DATA0
));
1227 for (buf
= 0; buf
< numBuffers
; buf
++) {
1228 struct gl_renderbuffer
*rb
= fb
->_ColorDrawBuffers
[buf
];
1230 /* color[fragOutput] will be written to buffer[buf] */
1233 GLchan rgbaSave
[MAX_WIDTH
][4];
1234 const GLuint fragOutput
= multiFragOutputs
? buf
: 0;
1236 /* set span->array->rgba to colors for render buffer's datatype */
1237 if (rb
->DataType
!= span
->array
->ChanType
|| fragOutput
> 0) {
1238 convert_color_type(span
, rb
->DataType
, fragOutput
);
1241 if (rb
->DataType
== GL_UNSIGNED_BYTE
) {
1242 span
->array
->rgba
= span
->array
->rgba8
;
1244 else if (rb
->DataType
== GL_UNSIGNED_SHORT
) {
1245 span
->array
->rgba
= (void *) span
->array
->rgba16
;
1248 span
->array
->rgba
= (void *)
1249 span
->array
->attribs
[FRAG_ATTRIB_COL0
];
1253 if (!multiFragOutputs
&& numBuffers
> 1) {
1254 /* save colors for second, third renderbuffer writes */
1255 memcpy(rgbaSave
, span
->array
->rgba
,
1256 4 * span
->end
* sizeof(GLchan
));
1259 ASSERT(rb
->_BaseFormat
== GL_RGBA
|| rb
->_BaseFormat
== GL_RGB
||
1260 rb
->_BaseFormat
== GL_ALPHA
);
1262 if (ctx
->Color
._LogicOpEnabled
) {
1263 _swrast_logicop_rgba_span(ctx
, rb
, span
);
1265 else if ((ctx
->Color
.BlendEnabled
>> buf
) & 1) {
1266 _swrast_blend_span(ctx
, rb
, span
);
1269 if (colorMask
[buf
] != 0xffffffff) {
1270 _swrast_mask_rgba_span(ctx
, rb
, span
, buf
);
1273 if (span
->arrayMask
& SPAN_XY
) {
1274 /* array of pixel coords */
1275 ASSERT(rb
->PutValues
);
1276 rb
->PutValues(ctx
, rb
, span
->end
,
1277 span
->array
->x
, span
->array
->y
,
1278 span
->array
->rgba
, span
->array
->mask
);
1281 /* horizontal run of pixels */
1283 rb
->PutRow(ctx
, rb
, span
->end
, span
->x
, span
->y
,
1285 span
->writeAll
? NULL
: span
->array
->mask
);
1288 if (!multiFragOutputs
&& numBuffers
> 1) {
1289 /* restore original span values */
1290 memcpy(span
->array
->rgba
, rgbaSave
,
1291 4 * span
->end
* sizeof(GLchan
));
1299 /* restore these values before returning */
1300 span
->interpMask
= origInterpMask
;
1301 span
->arrayMask
= origArrayMask
;
1302 span
->arrayAttribs
= origArrayAttribs
;
1303 span
->array
->ChanType
= origChanType
;
1304 span
->array
->rgba
= origRgba
;
1309 * Read RGBA pixels from a renderbuffer. Clipping will be done to prevent
1310 * reading ouside the buffer's boundaries.
1311 * \param dstType datatype for returned colors
1312 * \param rgba the returned colors
1315 _swrast_read_rgba_span( struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1316 GLuint n
, GLint x
, GLint y
, GLenum dstType
,
1319 const GLint bufWidth
= (GLint
) rb
->Width
;
1320 const GLint bufHeight
= (GLint
) rb
->Height
;
1322 if (y
< 0 || y
>= bufHeight
|| x
+ (GLint
) n
< 0 || x
>= bufWidth
) {
1323 /* completely above, below, or right */
1324 /* XXX maybe leave rgba values undefined? */
1325 memset(rgba
, 0, 4 * n
* sizeof(GLchan
));
1330 /* left edge clipping */
1332 length
= (GLint
) n
- skip
;
1334 /* completely left of window */
1337 if (length
> bufWidth
) {
1341 else if ((GLint
) (x
+ n
) > bufWidth
) {
1342 /* right edge clipping */
1344 length
= bufWidth
- x
;
1346 /* completely to right of window */
1358 ASSERT(rb
->_BaseFormat
== GL_RGBA
||
1359 rb
->_BaseFormat
== GL_RGB
||
1360 rb
->_BaseFormat
== GL_RG
||
1361 rb
->_BaseFormat
== GL_RED
||
1362 rb
->_BaseFormat
== GL_LUMINANCE
||
1363 rb
->_BaseFormat
== GL_INTENSITY
||
1364 rb
->_BaseFormat
== GL_LUMINANCE_ALPHA
||
1365 rb
->_BaseFormat
== GL_ALPHA
);
1367 if (rb
->DataType
== dstType
) {
1368 rb
->GetRow(ctx
, rb
, length
, x
+ skip
, y
,
1369 (GLubyte
*) rgba
+ skip
* RGBA_PIXEL_SIZE(rb
->DataType
));
1372 GLuint temp
[MAX_WIDTH
* 4];
1373 rb
->GetRow(ctx
, rb
, length
, x
+ skip
, y
, temp
);
1374 _mesa_convert_colors(rb
->DataType
, temp
,
1375 dstType
, (GLubyte
*) rgba
+ skip
* RGBA_PIXEL_SIZE(dstType
),
1383 * Wrapper for gl_renderbuffer::GetValues() which does clipping to avoid
1384 * reading values outside the buffer bounds.
1385 * We can use this for reading any format/type of renderbuffer.
1386 * \param valueSize is the size in bytes of each value (pixel) put into the
1390 _swrast_get_values(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1391 GLuint count
, const GLint x
[], const GLint y
[],
1392 void *values
, GLuint valueSize
)
1394 GLuint i
, inCount
= 0, inStart
= 0;
1396 for (i
= 0; i
< count
; i
++) {
1397 if (x
[i
] >= 0 && y
[i
] >= 0 &&
1398 x
[i
] < (GLint
) rb
->Width
&& y
[i
] < (GLint
) rb
->Height
) {
1406 /* read [inStart, inStart + inCount) */
1407 rb
->GetValues(ctx
, rb
, inCount
, x
+ inStart
, y
+ inStart
,
1408 (GLubyte
*) values
+ inStart
* valueSize
);
1414 /* read last values */
1415 rb
->GetValues(ctx
, rb
, inCount
, x
+ inStart
, y
+ inStart
,
1416 (GLubyte
*) values
+ inStart
* valueSize
);
1422 * Wrapper for gl_renderbuffer::PutRow() which does clipping.
1423 * \param valueSize size of each value (pixel) in bytes
1426 _swrast_put_row(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1427 GLuint count
, GLint x
, GLint y
,
1428 const GLvoid
*values
, GLuint valueSize
)
1432 if (y
< 0 || y
>= (GLint
) rb
->Height
)
1433 return; /* above or below */
1435 if (x
+ (GLint
) count
<= 0 || x
>= (GLint
) rb
->Width
)
1436 return; /* entirely left or right */
1438 if ((GLint
) (x
+ count
) > (GLint
) rb
->Width
) {
1440 GLint clip
= x
+ count
- rb
->Width
;
1451 rb
->PutRow(ctx
, rb
, count
, x
, y
,
1452 (const GLubyte
*) values
+ skip
* valueSize
, NULL
);
1457 * Wrapper for gl_renderbuffer::GetRow() which does clipping.
1458 * \param valueSize size of each value (pixel) in bytes
1461 _swrast_get_row(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1462 GLuint count
, GLint x
, GLint y
,
1463 GLvoid
*values
, GLuint valueSize
)
1467 if (y
< 0 || y
>= (GLint
) rb
->Height
)
1468 return; /* above or below */
1470 if (x
+ (GLint
) count
<= 0 || x
>= (GLint
) rb
->Width
)
1471 return; /* entirely left or right */
1473 if (x
+ count
> rb
->Width
) {
1475 GLint clip
= x
+ count
- rb
->Width
;
1486 rb
->GetRow(ctx
, rb
, count
, x
, y
, (GLubyte
*) values
+ skip
* valueSize
);
1491 * Get RGBA pixels from the given renderbuffer.
1492 * Used by blending, logicop and masking functions.
1493 * \return pointer to the colors we read.
1496 _swrast_get_dest_rgba(struct gl_context
*ctx
, struct gl_renderbuffer
*rb
,
1499 const GLuint pixelSize
= RGBA_PIXEL_SIZE(span
->array
->ChanType
);
1502 /* Point rbPixels to a temporary space */
1503 rbPixels
= span
->array
->attribs
[FRAG_ATTRIB_MAX
- 1];
1505 /* Get destination values from renderbuffer */
1506 if (span
->arrayMask
& SPAN_XY
) {
1507 _swrast_get_values(ctx
, rb
, span
->end
, span
->array
->x
, span
->array
->y
,
1508 rbPixels
, pixelSize
);
1511 _swrast_get_row(ctx
, rb
, span
->end
, span
->x
, span
->y
,
1512 rbPixels
, pixelSize
);