2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2005 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 * Functions for allocating/managing framebuffers and renderbuffers.
28 * Also, routines for reading/writing renderbuffer data as ubytes,
29 * ushorts, uints, etc.
38 #include "framebuffer.h"
39 #include "renderbuffer.h"
44 * Compute/set the _DepthMax field for the given framebuffer.
45 * This value depends on the Z buffer resolution.
48 compute_depth_max(struct gl_framebuffer
*fb
)
50 if (fb
->Visual
.depthBits
== 0) {
51 /* Special case. Even if we don't have a depth buffer we need
52 * good values for DepthMax for Z vertex transformation purposes
53 * and for per-fragment fog computation.
55 fb
->_DepthMax
= (1 << 16) - 1;
57 else if (fb
->Visual
.depthBits
< 32) {
58 fb
->_DepthMax
= (1 << fb
->Visual
.depthBits
) - 1;
61 /* Special case since shift values greater than or equal to the
62 * number of bits in the left hand expression's type are undefined.
64 fb
->_DepthMax
= 0xffffffff;
66 fb
->_DepthMaxF
= (GLfloat
) fb
->_DepthMax
;
67 fb
->_MRD
= 1.0; /* Minimum resolvable depth value, for polygon offset */
72 * Create and initialize a gl_framebuffer object.
73 * This is intended for creating _window_system_ framebuffers, not generic
74 * framebuffer objects ala GL_EXT_framebuffer_object.
76 * \sa _mesa_new_framebuffer
78 struct gl_framebuffer
*
79 _mesa_create_framebuffer(const GLvisual
*visual
)
81 struct gl_framebuffer
*fb
= CALLOC_STRUCT(gl_framebuffer
);
84 _mesa_initialize_framebuffer(fb
, visual
);
91 * Allocate a new gl_framebuffer object.
92 * This is the default function for ctx->Driver.NewFramebuffer().
93 * This is for allocating user-created framebuffers, not window-system
95 * \sa _mesa_create_framebuffer
97 struct gl_framebuffer
*
98 _mesa_new_framebuffer(GLcontext
*ctx
, GLuint name
)
100 struct gl_framebuffer
*fb
;
102 fb
= CALLOC_STRUCT(gl_framebuffer
);
106 fb
->Delete
= _mesa_destroy_framebuffer
;
107 fb
->ColorDrawBuffer
[0] = GL_COLOR_ATTACHMENT0_EXT
;
108 fb
->_ColorDrawBufferMask
[0] = BUFFER_BIT_COLOR0
;
109 fb
->ColorReadBuffer
= GL_COLOR_ATTACHMENT0_EXT
;
110 fb
->_ColorReadBufferMask
= BUFFER_BIT_COLOR0
;
111 fb
->Delete
= _mesa_destroy_framebuffer
;
118 * Initialize a gl_framebuffer object.
119 * \sa _mesa_create_framebuffer
122 _mesa_initialize_framebuffer(struct gl_framebuffer
*fb
, const GLvisual
*visual
)
127 _mesa_bzero(fb
, sizeof(struct gl_framebuffer
));
129 /* save the visual */
130 fb
->Visual
= *visual
;
132 /* Init glRead/DrawBuffer state */
133 if (visual
->doubleBufferMode
) {
134 fb
->ColorDrawBuffer
[0] = GL_BACK
;
135 fb
->_ColorDrawBufferMask
[0] = BUFFER_BIT_BACK_LEFT
;
136 fb
->ColorReadBuffer
= GL_BACK
;
137 fb
->_ColorReadBufferMask
= BUFFER_BIT_BACK_LEFT
;
140 fb
->ColorDrawBuffer
[0] = GL_FRONT
;
141 fb
->_ColorDrawBufferMask
[0] = BUFFER_BIT_FRONT_LEFT
;
142 fb
->ColorReadBuffer
= GL_FRONT
;
143 fb
->_ColorReadBufferMask
= BUFFER_BIT_FRONT_LEFT
;
146 fb
->Delete
= _mesa_destroy_framebuffer
;
148 compute_depth_max(fb
);
153 * Create/attach software-based renderbuffers to the given framebuffer.
154 * This is a helper routine for device drivers. Drivers can just as well
155 * call the individual _mesa_add_*_renderbuffer() routines directly.
158 _mesa_add_soft_renderbuffers(struct gl_framebuffer
*fb
,
166 GLboolean frontLeft
= GL_TRUE
;
167 GLboolean backLeft
= fb
->Visual
.doubleBufferMode
;
168 GLboolean frontRight
= fb
->Visual
.stereoMode
;
169 GLboolean backRight
= fb
->Visual
.stereoMode
&& fb
->Visual
.doubleBufferMode
;
172 if (fb
->Visual
.rgbMode
) {
173 assert(fb
->Visual
.redBits
== fb
->Visual
.greenBits
);
174 assert(fb
->Visual
.redBits
== fb
->Visual
.blueBits
);
175 _mesa_add_color_renderbuffers(NULL
, fb
,
177 fb
->Visual
.alphaBits
,
179 frontRight
, backRight
);
182 _mesa_add_color_index_renderbuffers(NULL
, fb
,
183 fb
->Visual
.indexBits
,
185 frontRight
, backRight
);
190 assert(fb
->Visual
.depthBits
> 0);
191 _mesa_add_depth_renderbuffer(NULL
, fb
, fb
->Visual
.depthBits
);
195 assert(fb
->Visual
.stencilBits
> 0);
196 _mesa_add_stencil_renderbuffer(NULL
, fb
, fb
->Visual
.stencilBits
);
200 assert(fb
->Visual
.rgbMode
);
201 assert(fb
->Visual
.accumRedBits
> 0);
202 assert(fb
->Visual
.accumGreenBits
> 0);
203 assert(fb
->Visual
.accumBlueBits
> 0);
204 _mesa_add_accum_renderbuffer(NULL
, fb
,
205 fb
->Visual
.accumRedBits
,
206 fb
->Visual
.accumGreenBits
,
207 fb
->Visual
.accumBlueBits
,
208 fb
->Visual
.accumAlphaBits
);
212 assert(fb
->Visual
.rgbMode
);
213 assert(fb
->Visual
.numAuxBuffers
> 0);
214 _mesa_add_aux_renderbuffers(NULL
, fb
, fb
->Visual
.redBits
,
215 fb
->Visual
.numAuxBuffers
);
220 assert(fb
->Visual
.rgbMode
);
221 assert(fb
->Visual
.alphaBits
> 0);
222 _mesa_add_alpha_renderbuffers(NULL
, fb
, fb
->Visual
.alphaBits
,
224 frontRight
, backRight
);
237 * Deallocate buffer and everything attached to it.
240 _mesa_destroy_framebuffer(struct gl_framebuffer
*buffer
)
243 _mesa_free_framebuffer_data(buffer
);
250 * Free all the data hanging off the given gl_framebuffer, but don't free
251 * the gl_framebuffer object itself.
254 _mesa_free_framebuffer_data(struct gl_framebuffer
*fb
)
260 for (i
= 0; i
< BUFFER_COUNT
; i
++) {
261 struct gl_renderbuffer_attachment
*att
= &fb
->Attachment
[i
];
262 if (att
->Type
== GL_RENDERBUFFER_EXT
&& att
->Renderbuffer
) {
263 struct gl_renderbuffer
*rb
= att
->Renderbuffer
;
265 if (rb
->RefCount
== 0) {
270 att
->Renderbuffer
= NULL
;
276 * Resize the given framebuffer's renderbuffers to the new width and height.
277 * This should only be used for window-system framebuffers, not
278 * user-created renderbuffers (i.e. made with GL_EXT_framebuffer_object).
279 * This will typically be called via ctx->Driver.ResizeBuffers()
282 _mesa_resize_framebuffer(GLcontext
*ctx
, struct gl_framebuffer
*fb
,
283 GLuint width
, GLuint height
)
287 /* For window system framebuffers, Name is zero */
288 assert(fb
->Name
== 0);
290 for (i
= 0; i
< BUFFER_COUNT
; i
++) {
291 struct gl_renderbuffer_attachment
*att
= &fb
->Attachment
[i
];
292 if (att
->Type
== GL_RENDERBUFFER_EXT
&& att
->Renderbuffer
) {
293 struct gl_renderbuffer
*rb
= att
->Renderbuffer
;
294 /* only resize if size is changing */
295 if (rb
->Width
!= width
|| rb
->Height
!= height
) {
296 if (rb
->AllocStorage(ctx
, rb
, rb
->InternalFormat
, width
, height
)) {
301 _mesa_error(ctx
, GL_OUT_OF_MEMORY
, "Resizing framebuffer");
313 * Examine all the framebuffer's renderbuffers to update the Width/Height
314 * fields of the framebuffer. If we have renderbuffers with different
315 * sizes, set the framebuffer's width and height to zero.
316 * Note: this is only intended for user-created framebuffers, not
317 * window-system framebuffes.
320 update_framebuffer_size(struct gl_framebuffer
*fb
)
322 GLboolean haveSize
= GL_FALSE
;
325 /* user-created framebuffers only */
328 for (i
= 0; i
< BUFFER_COUNT
; i
++) {
329 struct gl_renderbuffer_attachment
*att
= &fb
->Attachment
[i
];
330 const struct gl_renderbuffer
*rb
= att
->Renderbuffer
;
333 if (rb
->Width
!= fb
->Width
&& rb
->Height
!= fb
->Height
) {
341 fb
->Width
= rb
->Width
;
342 fb
->Height
= rb
->Height
;
351 * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
352 * These values are computed from the buffer's width and height and
353 * the scissor box, if it's enabled.
354 * \param ctx the GL context.
357 _mesa_update_draw_buffer_bounds(GLcontext
*ctx
)
359 struct gl_framebuffer
*buffer
= ctx
->DrawBuffer
;
362 /* user-created framebuffer size depends on the renderbuffers */
363 update_framebuffer_size(buffer
);
368 buffer
->_Xmax
= buffer
->Width
;
369 buffer
->_Ymax
= buffer
->Height
;
371 if (ctx
->Scissor
.Enabled
) {
372 if (ctx
->Scissor
.X
> buffer
->_Xmin
) {
373 buffer
->_Xmin
= ctx
->Scissor
.X
;
375 if (ctx
->Scissor
.Y
> buffer
->_Ymin
) {
376 buffer
->_Ymin
= ctx
->Scissor
.Y
;
378 if (ctx
->Scissor
.X
+ ctx
->Scissor
.Width
< buffer
->_Xmax
) {
379 buffer
->_Xmax
= ctx
->Scissor
.X
+ ctx
->Scissor
.Width
;
381 if (ctx
->Scissor
.Y
+ ctx
->Scissor
.Height
< buffer
->_Ymax
) {
382 buffer
->_Ymax
= ctx
->Scissor
.Y
+ ctx
->Scissor
.Height
;
384 /* finally, check for empty region */
385 if (buffer
->_Xmin
> buffer
->_Xmax
) {
386 buffer
->_Xmin
= buffer
->_Xmax
;
388 if (buffer
->_Ymin
> buffer
->_Ymax
) {
389 buffer
->_Ymin
= buffer
->_Ymax
;
393 ASSERT(buffer
->_Xmin
<= buffer
->_Xmax
);
394 ASSERT(buffer
->_Ymin
<= buffer
->_Ymax
);
399 * The glGet queries of the framebuffer red/green/blue size, stencil size,
400 * etc. are satisfied by the fields of ctx->DrawBuffer->Visual. These can
401 * change depending on the renderbuffer bindings. This function update's
402 * the given framebuffer's Visual from the current renderbuffer bindings.
403 * This is only intended for user-created framebuffers.
406 _mesa_update_framebuffer_visual(struct gl_framebuffer
*fb
)
408 assert(fb
->Name
!= 0);
410 _mesa_bzero(&fb
->Visual
, sizeof(fb
->Visual
));
411 fb
->Visual
.rgbMode
= GL_TRUE
;
413 if (fb
->Attachment
[BUFFER_FRONT_LEFT
].Renderbuffer
) {
415 = fb
->Attachment
[BUFFER_FRONT_LEFT
].Renderbuffer
->ComponentSizes
[0];
417 = fb
->Attachment
[BUFFER_FRONT_LEFT
].Renderbuffer
->ComponentSizes
[1];
419 = fb
->Attachment
[BUFFER_FRONT_LEFT
].Renderbuffer
->ComponentSizes
[2];
421 = fb
->Attachment
[BUFFER_FRONT_LEFT
].Renderbuffer
->ComponentSizes
[3];
423 = fb
->Visual
.redBits
+ fb
->Visual
.greenBits
+ fb
->Visual
.blueBits
;
424 fb
->Visual
.floatMode
= GL_FALSE
;
427 if (fb
->Attachment
[BUFFER_DEPTH
].Renderbuffer
) {
428 fb
->Visual
.haveDepthBuffer
= GL_TRUE
;
430 = fb
->Attachment
[BUFFER_DEPTH
].Renderbuffer
->ComponentSizes
[0];
433 if (fb
->Attachment
[BUFFER_STENCIL
].Renderbuffer
) {
434 fb
->Visual
.haveStencilBuffer
= GL_TRUE
;
435 fb
->Visual
.stencilBits
436 = fb
->Attachment
[BUFFER_STENCIL
].Renderbuffer
->ComponentSizes
[0];
439 compute_depth_max(fb
);
444 * Given a framebuffer and a buffer bit (like BUFFER_BIT_FRONT_LEFT), return
445 * the corresponding renderbuffer.
447 static struct gl_renderbuffer
*
448 get_renderbuffer(struct gl_framebuffer
*fb
, GLuint bufferBit
)
451 for (index
= 0; index
< BUFFER_COUNT
; index
++) {
452 if ((1 << index
) == bufferBit
) {
453 return fb
->Attachment
[index
].Renderbuffer
;
456 _mesa_problem(NULL
, "Bad bufferBit in get_renderbuffer");
462 * Update state related to the current draw/read framebuffers.
463 * If the current framebuffer is user-created, make sure it's complete.
466 _mesa_update_framebuffer(GLcontext
*ctx
)
468 struct gl_framebuffer
*fb
= ctx
->DrawBuffer
;
471 /* Completeness only matters for user-created framebuffers */
473 _mesa_test_framebuffer_completeness(ctx
, fb
);
476 * Update the list of drawing renderbuffer pointers.
477 * Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
478 * writing colors. We have a loop because glDrawBuffer(GL_FRONT_AND_BACK)
479 * can specify writing to two or four color buffers.
481 for (output
= 0; output
< ctx
->Const
.MaxDrawBuffers
; output
++) {
482 GLuint bufferMask
= fb
->_ColorDrawBufferMask
[output
];
485 /* for each bit that's set in the bufferMask... */
486 for (bufferBit
= 1; bufferMask
; bufferBit
<<= 1) {
487 if (bufferBit
& bufferMask
) {
488 struct gl_renderbuffer
*rb
= get_renderbuffer(fb
, bufferBit
);
490 fb
->_ColorDrawBuffers
[output
][count
] = rb
;
491 fb
->_ColorDrawBit
[output
][count
] = bufferBit
;
495 _mesa_warning(ctx
, "DrawBuffer names a missing buffer!");
497 bufferMask
&= ~bufferBit
;
500 fb
->_NumColorDrawBuffers
[output
] = count
;
504 * Update the read renderbuffer pointer.
505 * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
507 if (fb
->_ColorReadBufferMask
== 0x0)
508 fb
->_ColorReadBuffer
= NULL
; /* legal! */
510 fb
->_ColorReadBuffer
= get_renderbuffer(fb
, fb
->_ColorReadBufferMask
);
512 compute_depth_max(fb
);