2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
27 #include "bufferobj.h"
38 #include "s_context.h"
41 #include "s_stencil.h"
45 * Read a block of color index pixels.
48 read_index_pixels( GLcontext
*ctx
,
50 GLsizei width
, GLsizei height
,
51 GLenum type
, GLvoid
*pixels
,
52 const struct gl_pixelstore_attrib
*packing
)
54 struct gl_renderbuffer
*rb
= ctx
->ReadBuffer
->_ColorReadBuffer
;
59 /* width should never be > MAX_WIDTH since we did clipping earlier */
60 ASSERT(width
<= MAX_WIDTH
);
62 /* process image row by row */
63 for (i
= 0; i
< height
; i
++) {
64 GLuint index
[MAX_WIDTH
];
66 ASSERT(rb
->DataType
== GL_UNSIGNED_INT
);
67 rb
->GetRow(ctx
, rb
, width
, x
, y
+ i
, index
);
69 dest
= _mesa_image_address2d(packing
, pixels
, width
, height
,
70 GL_COLOR_INDEX
, type
, i
, 0);
72 _mesa_pack_index_span(ctx
, width
, type
, dest
, index
,
73 &ctx
->Pack
, ctx
->_ImageTransferState
);
80 * Read pixels for format=GL_DEPTH_COMPONENT.
83 read_depth_pixels( GLcontext
*ctx
,
85 GLsizei width
, GLsizei height
,
86 GLenum type
, GLvoid
*pixels
,
87 const struct gl_pixelstore_attrib
*packing
)
89 struct gl_framebuffer
*fb
= ctx
->ReadBuffer
;
90 struct gl_renderbuffer
*rb
= fb
->_DepthBuffer
;
91 const GLboolean biasOrScale
92 = ctx
->Pixel
.DepthScale
!= 1.0 || ctx
->Pixel
.DepthBias
!= 0.0;
94 /* clipping should have been done already */
97 ASSERT(x
+ width
<= rb
->Width
);
98 ASSERT(y
+ height
<= rb
->Height
);
99 /* width should never be > MAX_WIDTH since we did clipping earlier */
100 ASSERT(width
<= MAX_WIDTH
);
104 if (type
== GL_UNSIGNED_SHORT
&& fb
->Visual
.depthBits
== 16
105 && !biasOrScale
&& !packing
->SwapBytes
) {
106 /* Special case: directly read 16-bit unsigned depth values. */
108 ASSERT(rb
->InternalFormat
== GL_DEPTH_COMPONENT16
);
109 ASSERT(rb
->DataType
== GL_UNSIGNED_SHORT
);
110 for (j
= 0; j
< height
; j
++, y
++) {
111 void *dest
=_mesa_image_address2d(packing
, pixels
, width
, height
,
112 GL_DEPTH_COMPONENT
, type
, j
, 0);
113 rb
->GetRow(ctx
, rb
, width
, x
, y
, dest
);
116 else if (type
== GL_UNSIGNED_INT
&& fb
->Visual
.depthBits
== 24
117 && !biasOrScale
&& !packing
->SwapBytes
) {
118 /* Special case: directly read 24-bit unsigned depth values. */
120 ASSERT(rb
->InternalFormat
== GL_DEPTH_COMPONENT32
);
121 ASSERT(rb
->DataType
== GL_UNSIGNED_INT
);
122 for (j
= 0; j
< height
; j
++, y
++) {
123 GLuint
*dest
= (GLuint
*)
124 _mesa_image_address2d(packing
, pixels
, width
, height
,
125 GL_DEPTH_COMPONENT
, type
, j
, 0);
127 rb
->GetRow(ctx
, rb
, width
, x
, y
, dest
);
128 /* convert range from 24-bit to 32-bit */
129 for (k
= 0; k
< width
; k
++) {
130 dest
[k
] = (dest
[k
] << 8) | (dest
[k
] >> 24);
134 else if (type
== GL_UNSIGNED_INT
&& fb
->Visual
.depthBits
== 32
135 && !biasOrScale
&& !packing
->SwapBytes
) {
136 /* Special case: directly read 32-bit unsigned depth values. */
138 ASSERT(rb
->InternalFormat
== GL_DEPTH_COMPONENT32
);
139 ASSERT(rb
->DataType
== GL_UNSIGNED_INT
);
140 for (j
= 0; j
< height
; j
++, y
++) {
141 void *dest
= _mesa_image_address2d(packing
, pixels
, width
, height
,
142 GL_DEPTH_COMPONENT
, type
, j
, 0);
143 rb
->GetRow(ctx
, rb
, width
, x
, y
, dest
);
147 /* General case (slower) */
149 for (j
= 0; j
< height
; j
++, y
++) {
150 GLfloat depthValues
[MAX_WIDTH
];
151 GLvoid
*dest
= _mesa_image_address2d(packing
, pixels
, width
, height
,
152 GL_DEPTH_COMPONENT
, type
, j
, 0);
153 _swrast_read_depth_span_float(ctx
, rb
, width
, x
, y
, depthValues
);
154 _mesa_pack_depth_span(ctx
, width
, dest
, type
, depthValues
, packing
);
161 * Read pixels for format=GL_STENCIL_INDEX.
164 read_stencil_pixels( GLcontext
*ctx
,
166 GLsizei width
, GLsizei height
,
167 GLenum type
, GLvoid
*pixels
,
168 const struct gl_pixelstore_attrib
*packing
)
170 struct gl_framebuffer
*fb
= ctx
->ReadBuffer
;
171 struct gl_renderbuffer
*rb
= fb
->_StencilBuffer
;
176 /* width should never be > MAX_WIDTH since we did clipping earlier */
177 ASSERT(width
<= MAX_WIDTH
);
179 /* process image row by row */
180 for (j
=0;j
<height
;j
++,y
++) {
182 GLstencil stencil
[MAX_WIDTH
];
184 _swrast_read_stencil_span(ctx
, rb
, width
, x
, y
, stencil
);
186 dest
= _mesa_image_address2d(packing
, pixels
, width
, height
,
187 GL_STENCIL_INDEX
, type
, j
, 0);
189 _mesa_pack_stencil_span(ctx
, width
, type
, dest
, stencil
, packing
);
196 * Optimized glReadPixels for particular pixel formats when pixel
197 * scaling, biasing, mapping, etc. are disabled.
200 fast_read_rgba_pixels( GLcontext
*ctx
,
202 GLsizei width
, GLsizei height
,
203 GLenum format
, GLenum type
,
205 const struct gl_pixelstore_attrib
*packing
,
206 GLbitfield transferOps
)
208 struct gl_renderbuffer
*rb
= ctx
->ReadBuffer
->_ColorReadBuffer
;
210 ASSERT(rb
->_BaseFormat
== GL_RGBA
|| rb
->_BaseFormat
== GL_RGB
);
212 /* clipping should have already been done */
213 ASSERT(x
+ width
<= rb
->Width
);
214 ASSERT(y
+ height
<= rb
->Height
);
216 /* check for things we can't handle here */
218 packing
->SwapBytes
||
223 if (format
== GL_RGBA
&& rb
->DataType
== type
) {
224 const GLint dstStride
= _mesa_image_row_stride(packing
, width
,
226 GLubyte
*dest
= _mesa_image_address2d(packing
, pixels
, width
, height
,
230 for (row
= 0; row
< height
; row
++) {
231 rb
->GetRow(ctx
, rb
, width
, x
, y
+ row
, dest
);
237 if (format
== GL_RGB
&&
238 rb
->DataType
== GL_UNSIGNED_BYTE
&&
239 type
== GL_UNSIGNED_BYTE
) {
240 const GLint dstStride
= _mesa_image_row_stride(packing
, width
,
242 GLubyte
*dest
= _mesa_image_address2d(packing
, pixels
, width
, height
,
246 for (row
= 0; row
< height
; row
++) {
247 GLubyte tempRow
[MAX_WIDTH
][4];
249 rb
->GetRow(ctx
, rb
, width
, x
, y
+ row
, tempRow
);
250 /* convert RGBA to RGB */
251 for (col
= 0; col
< width
; col
++) {
252 dest
[col
* 3 + 0] = tempRow
[col
][0];
253 dest
[col
* 3 + 1] = tempRow
[col
][1];
254 dest
[col
* 3 + 2] = tempRow
[col
][2];
267 * When we're using a low-precision color buffer (like 16-bit 5/6/5)
268 * we have to adjust our color values a bit to pass conformance.
269 * The problem is when a 5 or 6-bit color value is convert to an 8-bit
270 * value and then a floating point value, the floating point values don't
271 * increment uniformly as the 5 or 6-bit value is incremented.
273 * This function adjusts floating point values to compensate.
276 adjust_colors(GLcontext
*ctx
, GLuint n
, GLfloat rgba
[][4])
278 const GLuint rShift
= 8 - ctx
->Visual
.redBits
;
279 const GLuint gShift
= 8 - ctx
->Visual
.greenBits
;
280 const GLuint bShift
= 8 - ctx
->Visual
.blueBits
;
281 const GLfloat rScale
= 1.0F
/ (GLfloat
) ((1 << ctx
->Visual
.redBits
) - 1);
282 const GLfloat gScale
= 1.0F
/ (GLfloat
) ((1 << ctx
->Visual
.greenBits
) - 1);
283 const GLfloat bScale
= 1.0F
/ (GLfloat
) ((1 << ctx
->Visual
.blueBits
) - 1);
285 for (i
= 0; i
< n
; i
++) {
287 /* convert float back to ubyte */
288 CLAMPED_FLOAT_TO_UBYTE(r
, rgba
[i
][RCOMP
]);
289 CLAMPED_FLOAT_TO_UBYTE(g
, rgba
[i
][GCOMP
]);
290 CLAMPED_FLOAT_TO_UBYTE(b
, rgba
[i
][BCOMP
]);
291 /* using only the N most significant bits of the ubyte value, convert to
294 rgba
[i
][RCOMP
] = (GLfloat
) (r
>> rShift
) * rScale
;
295 rgba
[i
][GCOMP
] = (GLfloat
) (g
>> gShift
) * gScale
;
296 rgba
[i
][BCOMP
] = (GLfloat
) (b
>> bShift
) * bScale
;
303 * Read R, G, B, A, RGB, L, or LA pixels.
306 read_rgba_pixels( GLcontext
*ctx
,
308 GLsizei width
, GLsizei height
,
309 GLenum format
, GLenum type
, GLvoid
*pixels
,
310 const struct gl_pixelstore_attrib
*packing
)
312 SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
313 GLbitfield transferOps
= ctx
->_ImageTransferState
;
314 struct gl_framebuffer
*fb
= ctx
->ReadBuffer
;
315 struct gl_renderbuffer
*rb
= fb
->_ColorReadBuffer
;
319 if (type
== GL_FLOAT
&& ((ctx
->Color
.ClampReadColor
== GL_TRUE
) ||
320 (ctx
->Color
.ClampReadColor
== GL_FIXED_ONLY_ARB
&&
321 rb
->DataType
!= GL_FLOAT
)))
322 transferOps
|= IMAGE_CLAMP_BIT
;
324 /* Try optimized path first */
325 if (fast_read_rgba_pixels(ctx
, x
, y
, width
, height
,
326 format
, type
, pixels
, packing
, transferOps
)) {
330 /* width should never be > MAX_WIDTH since we did clipping earlier */
331 ASSERT(width
<= MAX_WIDTH
);
333 if (ctx
->Pixel
.Convolution2DEnabled
|| ctx
->Pixel
.Separable2DEnabled
) {
334 GLfloat
*dest
, *src
, *tmpImage
, *convImage
;
337 tmpImage
= (GLfloat
*) _mesa_malloc(width
* height
* 4 * sizeof(GLfloat
));
339 _mesa_error(ctx
, GL_OUT_OF_MEMORY
, "glReadPixels");
342 convImage
= (GLfloat
*) _mesa_malloc(width
* height
* 4 * sizeof(GLfloat
));
344 _mesa_free(tmpImage
);
345 _mesa_error(ctx
, GL_OUT_OF_MEMORY
, "glReadPixels");
349 /* read full RGBA, FLOAT image */
351 for (row
= 0; row
< height
; row
++, y
++) {
352 if (fb
->Visual
.rgbMode
) {
353 _swrast_read_rgba_span(ctx
, rb
, width
, x
, y
, GL_FLOAT
, dest
);
356 GLuint index
[MAX_WIDTH
];
357 ASSERT(rb
->DataType
== GL_UNSIGNED_INT
);
358 rb
->GetRow(ctx
, rb
, width
, x
, y
, index
);
359 _mesa_apply_ci_transfer_ops(ctx
,
360 transferOps
& IMAGE_SHIFT_OFFSET_BIT
,
362 _mesa_map_ci_to_rgba(ctx
, width
, index
, (GLfloat (*)[4]) dest
);
364 _mesa_apply_rgba_transfer_ops(ctx
,
365 transferOps
& IMAGE_PRE_CONVOLUTION_BITS
,
366 width
, (GLfloat (*)[4]) dest
);
371 if (ctx
->Pixel
.Convolution2DEnabled
) {
372 _mesa_convolve_2d_image(ctx
, &width
, &height
, tmpImage
, convImage
);
375 ASSERT(ctx
->Pixel
.Separable2DEnabled
);
376 _mesa_convolve_sep_image(ctx
, &width
, &height
, tmpImage
, convImage
);
378 _mesa_free(tmpImage
);
380 /* finish transfer ops and pack the resulting image */
382 for (row
= 0; row
< height
; row
++) {
384 dest
= _mesa_image_address2d(packing
, pixels
, width
, height
,
385 format
, type
, row
, 0);
386 _mesa_pack_rgba_span_float(ctx
, width
, (GLfloat (*)[4]) src
,
387 format
, type
, dest
, packing
,
388 transferOps
& IMAGE_POST_CONVOLUTION_BITS
);
391 _mesa_free(convImage
);
395 const GLint dstStride
396 = _mesa_image_row_stride(packing
, width
, format
, type
);
397 GLfloat (*rgba
)[4] = swrast
->SpanArrays
->color
.sz4
.rgba
;
399 GLubyte
*dst
= _mesa_image_address2d(packing
, pixels
, width
, height
,
402 for (row
= 0; row
< height
; row
++, y
++) {
404 /* Get float rgba pixels */
405 if (fb
->Visual
.rgbMode
) {
406 _swrast_read_rgba_span(ctx
, rb
, width
, x
, y
, GL_FLOAT
, rgba
);
409 /* read CI and convert to RGBA */
410 GLuint index
[MAX_WIDTH
];
411 ASSERT(rb
->DataType
== GL_UNSIGNED_INT
);
412 rb
->GetRow(ctx
, rb
, width
, x
, y
, index
);
413 _mesa_apply_ci_transfer_ops(ctx
,
414 transferOps
& IMAGE_SHIFT_OFFSET_BIT
,
416 _mesa_map_ci_to_rgba(ctx
, width
, index
, rgba
);
419 /* apply fudge factor for shallow color buffers */
420 if (fb
->Visual
.redBits
< 8 ||
421 fb
->Visual
.greenBits
< 8 ||
422 fb
->Visual
.blueBits
< 8) {
423 adjust_colors(ctx
, width
, rgba
);
426 /* pack the row of RGBA pixels into user's buffer */
427 _mesa_pack_rgba_span_float(ctx
, width
, rgba
, format
, type
, dst
,
428 packing
, transferOps
);
437 * Read combined depth/stencil values.
438 * We'll have already done error checking to be sure the expected
439 * depth and stencil buffers really exist.
442 read_depth_stencil_pixels(GLcontext
*ctx
,
444 GLsizei width
, GLsizei height
,
445 GLenum type
, GLvoid
*pixels
,
446 const struct gl_pixelstore_attrib
*packing
)
448 const GLboolean scaleOrBias
449 = ctx
->Pixel
.DepthScale
!= 1.0 || ctx
->Pixel
.DepthBias
!= 0.0;
450 const GLboolean stencilTransfer
= ctx
->Pixel
.IndexShift
451 || ctx
->Pixel
.IndexOffset
|| ctx
->Pixel
.MapStencilFlag
;
452 struct gl_renderbuffer
*depthRb
, *stencilRb
;
454 depthRb
= ctx
->ReadBuffer
->_DepthBuffer
;
455 stencilRb
= ctx
->ReadBuffer
->_StencilBuffer
;
460 depthRb
= ctx
->ReadBuffer
->Attachment
[BUFFER_DEPTH
].Renderbuffer
;
461 stencilRb
= ctx
->ReadBuffer
->Attachment
[BUFFER_STENCIL
].Renderbuffer
;
463 if (depthRb
->_BaseFormat
== GL_DEPTH_STENCIL_EXT
&&
464 stencilRb
->_BaseFormat
== GL_DEPTH_STENCIL_EXT
&&
465 depthRb
== stencilRb
&&
468 /* This is the ideal case.
469 * Reading GL_DEPTH_STENCIL pixels from combined depth/stencil buffer.
470 * Plus, no pixel transfer ops to worry about!
473 GLint dstStride
= _mesa_image_row_stride(packing
, width
,
474 GL_DEPTH_STENCIL_EXT
, type
);
475 GLubyte
*dst
= (GLubyte
*) _mesa_image_address2d(packing
, pixels
,
477 GL_DEPTH_STENCIL_EXT
,
479 for (i
= 0; i
< height
; i
++) {
480 depthRb
->GetRow(ctx
, depthRb
, width
, x
, y
+ i
, dst
);
485 /* Reading GL_DEPTH_STENCIL pixels from separate depth/stencil buffers,
486 * or we need pixel transfer.
489 depthRb
= ctx
->ReadBuffer
->_DepthBuffer
;
490 stencilRb
= ctx
->ReadBuffer
->_StencilBuffer
;
492 for (i
= 0; i
< height
; i
++) {
493 GLstencil stencilVals
[MAX_WIDTH
];
495 GLuint
*depthStencilDst
= (GLuint
*)
496 _mesa_image_address2d(packing
, pixels
, width
, height
,
497 GL_DEPTH_STENCIL_EXT
, type
, i
, 0);
499 _swrast_read_stencil_span(ctx
, stencilRb
, width
,
500 x
, y
+ i
, stencilVals
);
502 if (!scaleOrBias
&& !stencilTransfer
503 && ctx
->ReadBuffer
->Visual
.depthBits
== 24) {
505 GLuint zVals
[MAX_WIDTH
]; /* 24-bit values! */
507 ASSERT(depthRb
->DataType
== GL_UNSIGNED_INT
);
508 /* note, we've already been clipped */
509 depthRb
->GetRow(ctx
, depthRb
, width
, x
, y
+ i
, zVals
);
510 for (j
= 0; j
< width
; j
++) {
511 depthStencilDst
[j
] = (zVals
[j
] << 8) | (stencilVals
[j
] & 0xff);
516 GLfloat depthVals
[MAX_WIDTH
];
517 _swrast_read_depth_span_float(ctx
, depthRb
, width
, x
, y
+ i
,
519 _mesa_pack_depth_stencil_span(ctx
, width
, depthStencilDst
,
520 depthVals
, stencilVals
, packing
);
529 * Software fallback routine for ctx->Driver.ReadPixels().
530 * By time we get here, all error checking will have been done.
533 _swrast_ReadPixels( GLcontext
*ctx
,
534 GLint x
, GLint y
, GLsizei width
, GLsizei height
,
535 GLenum format
, GLenum type
,
536 const struct gl_pixelstore_attrib
*packing
,
539 SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
540 struct gl_pixelstore_attrib clippedPacking
= *packing
;
542 /* Need to do RENDER_START before clipping or anything else since this
543 * is where a driver may grab the hw lock and get an updated window
546 RENDER_START(swrast
, ctx
);
549 _mesa_update_state(ctx
);
551 if (swrast
->NewState
)
552 _swrast_validate_derived( ctx
);
554 /* Do all needed clipping here, so that we can forget about it later */
555 if (!_mesa_clip_readpixels(ctx
, &x
, &y
, &width
, &height
, &clippedPacking
)) {
556 /* The ReadPixels region is totally outside the window bounds */
560 if (clippedPacking
.BufferObj
->Name
) {
563 if (!_mesa_validate_pbo_access(2, &clippedPacking
, width
, height
, 1,
564 format
, type
, pixels
)) {
565 _mesa_error(ctx
, GL_INVALID_OPERATION
,
566 "glReadPixels(invalid PBO access)");
569 buf
= (GLubyte
*) ctx
->Driver
.MapBuffer(ctx
, GL_PIXEL_PACK_BUFFER_EXT
,
571 clippedPacking
.BufferObj
);
573 /* buffer is already mapped - that's an error */
574 _mesa_error(ctx
, GL_INVALID_OPERATION
, "glReadPixels(PBO is mapped)");
577 pixels
= ADD_POINTERS(buf
, pixels
);
582 read_index_pixels(ctx
, x
, y
, width
, height
, type
, pixels
,
585 case GL_STENCIL_INDEX
:
586 read_stencil_pixels(ctx
, x
, y
, width
, height
, type
, pixels
,
589 case GL_DEPTH_COMPONENT
:
590 read_depth_pixels(ctx
, x
, y
, width
, height
, type
, pixels
,
599 case GL_LUMINANCE_ALPHA
:
604 read_rgba_pixels(ctx
, x
, y
, width
, height
,
605 format
, type
, pixels
, &clippedPacking
);
607 case GL_DEPTH_STENCIL_EXT
:
608 read_depth_stencil_pixels(ctx
, x
, y
, width
, height
,
609 type
, pixels
, &clippedPacking
);
612 _mesa_problem(ctx
, "unexpected format in _swrast_ReadPixels");
613 /* don't return yet, clean-up */
618 RENDER_FINISH(swrast
, ctx
);
620 if (clippedPacking
.BufferObj
->Name
) {
621 /* done with PBO so unmap it now */
622 ctx
->Driver
.UnmapBuffer(ctx
, GL_PIXEL_PACK_BUFFER_EXT
,
623 clippedPacking
.BufferObj
);