xm_api.c revision 3fd88089c03f2dbe634ba2611955c6d0a6b2ccd5
1/*
2 * Mesa 3-D graphics library
3 * Version:  6.5.2
4 *
5 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
6 *
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:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
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.
23 */
24
25/**
26 * \file xm_api.c
27 *
28 * All the XMesa* API functions.
29 *
30 *
31 * NOTES:
32 *
33 * The window coordinate system origin (0,0) is in the lower-left corner
34 * of the window.  X11's window coordinate origin is in the upper-left
35 * corner of the window.  Therefore, most drawing functions in this
36 * file have to flip Y coordinates.
37 *
38 * Define USE_XSHM in the Makefile with -DUSE_XSHM if you want to compile
39 * in support for the MIT Shared Memory extension.  If enabled, when you
40 * use an Ximage for the back buffer in double buffered mode, the "swap"
41 * operation will be faster.  You must also link with -lXext.
42 *
43 * Byte swapping:  If the Mesa host and the X display use a different
44 * byte order then there's some trickiness to be aware of when using
45 * XImages.  The byte ordering used for the XImage is that of the X
46 * display, not the Mesa host.
47 * The color-to-pixel encoding for True/DirectColor must be done
48 * according to the display's visual red_mask, green_mask, and blue_mask.
49 * If XPutPixel is used to put a pixel into an XImage then XPutPixel will
50 * do byte swapping if needed.  If one wants to directly "poke" the pixel
51 * into the XImage's buffer then the pixel must be byte swapped first.  In
52 * Mesa, when byte swapping is needed we use the PF_TRUECOLOR pixel format
53 * and use XPutPixel everywhere except in the implementation of
54 * glClear(GL_COLOR_BUFFER_BIT).  We want this function to be fast so
55 * instead of using XPutPixel we "poke" our values after byte-swapping
56 * the clear pixel value if needed.
57 *
58 */
59
60#ifdef __CYGWIN__
61#undef WIN32
62#undef __WIN32__
63#endif
64
65#include "glxheader.h"
66#include "GL/xmesa.h"
67#include "xmesaP.h"
68#include "context.h"
69#include "extensions.h"
70#include "framebuffer.h"
71#include "glthread.h"
72#include "imports.h"
73#include "macros.h"
74#include "renderbuffer.h"
75#include "swrast/swrast.h"
76#include "swrast_setup/swrast_setup.h"
77#include "vbo/vbo.h"
78#include "tnl/tnl.h"
79#include "tnl/t_context.h"
80#include "tnl/t_pipeline.h"
81#include "drivers/common/driverfuncs.h"
82
83/**
84 * Global X driver lock
85 */
86_glthread_Mutex _xmesa_lock;
87
88
89
90/**
91 * Lookup tables for HPCR pixel format:
92 */
93static short hpcr_rgbTbl[3][256] = {
94{
95 16,  16,  17,  17,  18,  18,  19,  19,  20,  20,  21,  21,  22,  22,  23,  23,
96 24,  24,  25,  25,  26,  26,  27,  27,  28,  28,  29,  29,  30,  30,  31,  31,
97 32,  32,  33,  33,  34,  34,  35,  35,  36,  36,  37,  37,  38,  38,  39,  39,
98 32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,
99 48,  49,  50,  51,  52,  53,  54,  55,  56,  57,  58,  59,  60,  61,  62,  63,
100 64,  65,  66,  67,  68,  69,  70,  71,  72,  73,  74,  75,  76,  77,  78,  79,
101 80,  81,  82,  83,  84,  85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,
102 96,  97,  98,  99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
103112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
104128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
105144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
106160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
107176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
108192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
109208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
110224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239
111},
112{
113 16,  16,  17,  17,  18,  18,  19,  19,  20,  20,  21,  21,  22,  22,  23,  23,
114 24,  24,  25,  25,  26,  26,  27,  27,  28,  28,  29,  29,  30,  30,  31,  31,
115 32,  32,  33,  33,  34,  34,  35,  35,  36,  36,  37,  37,  38,  38,  39,  39,
116 32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,
117 48,  49,  50,  51,  52,  53,  54,  55,  56,  57,  58,  59,  60,  61,  62,  63,
118 64,  65,  66,  67,  68,  69,  70,  71,  72,  73,  74,  75,  76,  77,  78,  79,
119 80,  81,  82,  83,  84,  85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,
120 96,  97,  98,  99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
121112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
122128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
123144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
124160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
125176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
126192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
127208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223,
128224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239
129},
130{
131 32,  32,  33,  33,  34,  34,  35,  35,  36,  36,  37,  37,  38,  38,  39,  39,
132 40,  40,  41,  41,  42,  42,  43,  43,  44,  44,  45,  45,  46,  46,  47,  47,
133 48,  48,  49,  49,  50,  50,  51,  51,  52,  52,  53,  53,  54,  54,  55,  55,
134 56,  56,  57,  57,  58,  58,  59,  59,  60,  60,  61,  61,  62,  62,  63,  63,
135 64,  64,  65,  65,  66,  66,  67,  67,  68,  68,  69,  69,  70,  70,  71,  71,
136 72,  72,  73,  73,  74,  74,  75,  75,  76,  76,  77,  77,  78,  78,  79,  79,
137 80,  80,  81,  81,  82,  82,  83,  83,  84,  84,  85,  85,  86,  86,  87,  87,
138 80,  81,  82,  83,  84,  85,  86,  87,  88,  89,  90,  91,  92,  93,  94,  95,
139 96,  97,  98,  99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
140112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
141128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
142144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
143160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175,
144176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,
145192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207,
146208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223
147}
148};
149
150
151
152/**********************************************************************/
153/*****                     X Utility Functions                    *****/
154/**********************************************************************/
155
156
157/**
158 * Return the host's byte order as LSBFirst or MSBFirst ala X.
159 */
160#ifndef XFree86Server
161static int host_byte_order( void )
162{
163   int i = 1;
164   char *cptr = (char *) &i;
165   return (*cptr==1) ? LSBFirst : MSBFirst;
166}
167#endif
168
169
170/**
171 * Check if the X Shared Memory extension is available.
172 * Return:  0 = not available
173 *          1 = shared XImage support available
174 *          2 = shared Pixmap support available also
175 */
176static int check_for_xshm( XMesaDisplay *display )
177{
178#if defined(USE_XSHM) && !defined(XFree86Server)
179   int major, minor, ignore;
180   Bool pixmaps;
181
182   if (XQueryExtension( display, "MIT-SHM", &ignore, &ignore, &ignore )) {
183      if (XShmQueryVersion( display, &major, &minor, &pixmaps )==True) {
184	 return (pixmaps==True) ? 2 : 1;
185      }
186      else {
187	 return 0;
188      }
189   }
190   else {
191      return 0;
192   }
193#else
194   /* No  XSHM support */
195   return 0;
196#endif
197}
198
199
200/**
201 * Apply gamma correction to an intensity value in [0..max].  Return the
202 * new intensity value.
203 */
204static GLint
205gamma_adjust( GLfloat gamma, GLint value, GLint max )
206{
207   if (gamma == 1.0) {
208      return value;
209   }
210   else {
211      double x = (double) value / (double) max;
212      return IROUND_POS((GLfloat) max * _mesa_pow(x, 1.0F/gamma));
213   }
214}
215
216
217
218/**
219 * Return the true number of bits per pixel for XImages.
220 * For example, if we request a 24-bit deep visual we may actually need/get
221 * 32bpp XImages.  This function returns the appropriate bpp.
222 * Input:  dpy - the X display
223 *         visinfo - desribes the visual to be used for XImages
224 * Return:  true number of bits per pixel for XImages
225 */
226static int
227bits_per_pixel( XMesaVisual xmv )
228{
229#ifdef XFree86Server
230   const int depth = xmv->nplanes;
231   int i;
232   assert(depth > 0);
233   for (i = 0; i < screenInfo.numPixmapFormats; i++) {
234      if (screenInfo.formats[i].depth == depth)
235         return screenInfo.formats[i].bitsPerPixel;
236   }
237   return depth;  /* should never get here, but this should be safe */
238#else
239   XMesaDisplay *dpy = xmv->display;
240   XMesaVisualInfo visinfo = xmv->visinfo;
241   XMesaImage *img;
242   int bitsPerPixel;
243   /* Create a temporary XImage */
244   img = XCreateImage( dpy, visinfo->visual, visinfo->depth,
245		       ZPixmap, 0,           /*format, offset*/
246		       (char*) MALLOC(8),    /*data*/
247		       1, 1,                 /*width, height*/
248		       32,                   /*bitmap_pad*/
249		       0                     /*bytes_per_line*/
250                     );
251   assert(img);
252   /* grab the bits/pixel value */
253   bitsPerPixel = img->bits_per_pixel;
254   /* free the XImage */
255   _mesa_free( img->data );
256   img->data = NULL;
257   XMesaDestroyImage( img );
258   return bitsPerPixel;
259#endif
260}
261
262
263
264/*
265 * Determine if a given X window ID is valid (window exists).
266 * Do this by calling XGetWindowAttributes() for the window and
267 * checking if we catch an X error.
268 * Input:  dpy - the display
269 *         win - the window to check for existance
270 * Return:  GL_TRUE - window exists
271 *          GL_FALSE - window doesn't exist
272 */
273#ifndef XFree86Server
274static GLboolean WindowExistsFlag;
275
276static int window_exists_err_handler( XMesaDisplay* dpy, XErrorEvent* xerr )
277{
278   (void) dpy;
279   if (xerr->error_code == BadWindow) {
280      WindowExistsFlag = GL_FALSE;
281   }
282   return 0;
283}
284
285static GLboolean window_exists( XMesaDisplay *dpy, Window win )
286{
287   XWindowAttributes wa;
288   int (*old_handler)( XMesaDisplay*, XErrorEvent* );
289   WindowExistsFlag = GL_TRUE;
290   old_handler = XSetErrorHandler(window_exists_err_handler);
291   XGetWindowAttributes( dpy, win, &wa ); /* dummy request */
292   XSetErrorHandler(old_handler);
293   return WindowExistsFlag;
294}
295#endif
296
297
298
299/**
300 * Return the size of the window (or pixmap) that corresponds to the
301 * given XMesaBuffer.
302 * \param width  returns width in pixels
303 * \param height  returns height in pixels
304 */
305void
306xmesa_get_window_size(XMesaDisplay *dpy, XMesaBuffer b,
307                      GLuint *width, GLuint *height)
308{
309#ifdef XFree86Server
310   *width = MIN2(b->frontxrb->drawable->width, MAX_WIDTH);
311   *height = MIN2(b->frontxrb->drawable->height, MAX_HEIGHT);
312#else
313   Window root;
314   Status stat;
315   int xpos, ypos;
316   unsigned int w, h, bw, depth;
317
318   _glthread_LOCK_MUTEX(_xmesa_lock);
319   XSync(b->xm_visual->display, 0); /* added for Chromium */
320   stat = XGetGeometry(dpy, b->frontxrb->pixmap, &root, &xpos, &ypos,
321                       &w, &h, &bw, &depth);
322   _glthread_UNLOCK_MUTEX(_xmesa_lock);
323
324   if (stat) {
325      *width = w;
326      *height = h;
327   }
328   else {
329      /* probably querying a window that's recently been destroyed */
330      _mesa_warning(NULL, "XGetGeometry failed!\n");
331      *width = *height = 1;
332   }
333#endif
334}
335
336
337
338/**********************************************************************/
339/*****                Linked list of XMesaBuffers                 *****/
340/**********************************************************************/
341
342XMesaBuffer XMesaBufferList = NULL;
343
344
345/**
346 * Allocate a new XMesaBuffer object which corresponds to the given drawable.
347 * Note that XMesaBuffer is derived from GLframebuffer.
348 * The new XMesaBuffer will not have any size (Width=Height=0).
349 *
350 * \param d  the corresponding X drawable (window or pixmap)
351 * \param type  either WINDOW, PIXMAP or PBUFFER, describing d
352 * \param vis  the buffer's visual
353 * \param cmap  the window's colormap, if known.
354 * \return new XMesaBuffer or NULL if any problem
355 */
356static XMesaBuffer
357create_xmesa_buffer(XMesaDrawable d, BufferType type,
358                    XMesaVisual vis, XMesaColormap cmap)
359{
360   XMesaBuffer b;
361
362   ASSERT(type == WINDOW || type == PIXMAP || type == PBUFFER);
363
364   b = (XMesaBuffer) CALLOC_STRUCT(xmesa_buffer);
365   if (!b)
366      return NULL;
367
368   b->display = vis->display;
369   b->xm_visual = vis;
370   b->type = type;
371   b->cmap = cmap;
372
373   _mesa_initialize_framebuffer(&b->mesa_buffer, &vis->mesa_visual);
374   b->mesa_buffer.Delete = xmesa_delete_framebuffer;
375
376   /*
377    * Front renderbuffer
378    */
379   b->frontxrb = xmesa_new_renderbuffer(NULL, 0, &vis->mesa_visual, GL_FALSE);
380   if (!b->frontxrb) {
381      _mesa_free(b);
382      return NULL;
383   }
384   b->frontxrb->Parent = b;
385   b->frontxrb->drawable = d;
386   b->frontxrb->pixmap = (XMesaPixmap) d;
387   _mesa_add_renderbuffer(&b->mesa_buffer, BUFFER_FRONT_LEFT,
388                          &b->frontxrb->Base);
389
390   /*
391    * Back renderbuffer
392    */
393   if (vis->mesa_visual.doubleBufferMode) {
394      b->backxrb = xmesa_new_renderbuffer(NULL, 0, &vis->mesa_visual, GL_TRUE);
395      if (!b->backxrb) {
396         /* XXX free front xrb too */
397         _mesa_free(b);
398         return NULL;
399      }
400      b->backxrb->Parent = b;
401      /* determine back buffer implementation */
402      b->db_mode = vis->ximage_flag ? BACK_XIMAGE : BACK_PIXMAP;
403
404      _mesa_add_renderbuffer(&b->mesa_buffer, BUFFER_BACK_LEFT,
405                             &b->backxrb->Base);
406   }
407
408   /*
409    * Software alpha planes
410    */
411   if (vis->mesa_visual.alphaBits > 0
412       && vis->undithered_pf != PF_8A8B8G8R
413       && vis->undithered_pf != PF_8A8R8G8B) {
414      /* Visual has alpha, but pixel format doesn't support it.
415       * We'll use an alpha renderbuffer wrapper.
416       */
417      b->swAlpha = GL_TRUE;
418   }
419   else {
420      b->swAlpha = GL_FALSE;
421   }
422
423   /*
424    * Other renderbuffer (depth, stencil, etc)
425    */
426   _mesa_add_soft_renderbuffers(&b->mesa_buffer,
427                                GL_FALSE,  /* color */
428                                vis->mesa_visual.haveDepthBuffer,
429                                vis->mesa_visual.haveStencilBuffer,
430                                vis->mesa_visual.haveAccumBuffer,
431                                b->swAlpha,
432                                vis->mesa_visual.numAuxBuffers > 0 );
433
434   /* insert buffer into linked list */
435   b->Next = XMesaBufferList;
436   XMesaBufferList = b;
437
438   return b;
439}
440
441
442/**
443 * Find an XMesaBuffer by matching X display and colormap but NOT matching
444 * the notThis buffer.
445 */
446XMesaBuffer
447xmesa_find_buffer(XMesaDisplay *dpy, XMesaColormap cmap, XMesaBuffer notThis)
448{
449   XMesaBuffer b;
450   for (b=XMesaBufferList; b; b=b->Next) {
451      if (b->display==dpy && b->cmap==cmap && b!=notThis) {
452         return b;
453      }
454   }
455   return NULL;
456}
457
458
459/**
460 * Remove buffer from linked list, delete if no longer referenced.
461 */
462static void
463xmesa_free_buffer(XMesaBuffer buffer)
464{
465   XMesaBuffer prev = NULL, b;
466
467   for (b = XMesaBufferList; b; b = b->Next) {
468      if (b == buffer) {
469         struct gl_framebuffer *fb = &buffer->mesa_buffer;
470
471         /* unlink buffer from list */
472         if (prev)
473            prev->Next = buffer->Next;
474         else
475            XMesaBufferList = buffer->Next;
476
477         /* mark as delete pending */
478         fb->DeletePending = GL_TRUE;
479
480         /* Since the X window for the XMesaBuffer is going away, we don't
481          * want to dereference this pointer in the future.
482          */
483         b->frontxrb->drawable = 0;
484
485         /* Unreference.  If count = zero we'll really delete the buffer */
486         _mesa_unreference_framebuffer(&fb);
487
488         return;
489      }
490      /* continue search */
491      prev = b;
492   }
493   /* buffer not found in XMesaBufferList */
494   _mesa_problem(NULL,"xmesa_free_buffer() - buffer not found\n");
495}
496
497
498/**
499 * Copy X color table stuff from one XMesaBuffer to another.
500 */
501static void
502copy_colortable_info(XMesaBuffer dst, const XMesaBuffer src)
503{
504   MEMCPY(dst->color_table, src->color_table, sizeof(src->color_table));
505   MEMCPY(dst->pixel_to_r, src->pixel_to_r, sizeof(src->pixel_to_r));
506   MEMCPY(dst->pixel_to_g, src->pixel_to_g, sizeof(src->pixel_to_g));
507   MEMCPY(dst->pixel_to_b, src->pixel_to_b, sizeof(src->pixel_to_b));
508   dst->num_alloced = src->num_alloced;
509   MEMCPY(dst->alloced_colors, src->alloced_colors,
510          sizeof(src->alloced_colors));
511}
512
513
514
515/**********************************************************************/
516/*****                   Misc Private Functions                   *****/
517/**********************************************************************/
518
519
520/**
521 * A replacement for XAllocColor.  This function should never
522 * fail to allocate a color.  When XAllocColor fails, we return
523 * the nearest matching color.  If we have to allocate many colors
524 * this function isn't too efficient; the XQueryColors() could be
525 * done just once.
526 * Written by Michael Pichler, Brian Paul, Mark Kilgard
527 * Input:  dpy - X display
528 *         cmap - X colormap
529 *         cmapSize - size of colormap
530 * In/Out: color - the XColor struct
531 * Output:  exact - 1=exact color match, 0=closest match
532 *          alloced - 1=XAlloc worked, 0=XAlloc failed
533 */
534static void
535noFaultXAllocColor( int client,
536                    XMesaDisplay *dpy,
537                    XMesaColormap cmap,
538                    int cmapSize,
539                    XMesaColor *color,
540                    int *exact, int *alloced )
541{
542#ifdef XFree86Server
543   Pixel *ppixIn;
544   xrgb *ctable;
545#else
546   /* we'll try to cache ctable for better remote display performance */
547   static Display *prevDisplay = NULL;
548   static XMesaColormap prevCmap = 0;
549   static int prevCmapSize = 0;
550   static XMesaColor *ctable = NULL;
551#endif
552   XMesaColor subColor;
553   int i, bestmatch;
554   double mindist;       /* 3*2^16^2 exceeds long int precision. */
555
556   (void) client;
557
558   /* First try just using XAllocColor. */
559#ifdef XFree86Server
560   if (AllocColor(cmap,
561		  &color->red, &color->green, &color->blue,
562		  &color->pixel,
563		  client) == Success)
564#else
565   if (XAllocColor(dpy, cmap, color))
566#endif
567   {
568      *exact = 1;
569      *alloced = 1;
570      return;
571   }
572
573   /* Alloc failed, search for closest match */
574
575   /* Retrieve color table entries. */
576   /* XXX alloca candidate. */
577#ifdef XFree86Server
578   ppixIn = (Pixel *) MALLOC(cmapSize * sizeof(Pixel));
579   ctable = (xrgb *) MALLOC(cmapSize * sizeof(xrgb));
580   for (i = 0; i < cmapSize; i++) {
581      ppixIn[i] = i;
582   }
583   QueryColors(cmap, cmapSize, ppixIn, ctable);
584#else
585   if (prevDisplay != dpy || prevCmap != cmap
586       || prevCmapSize != cmapSize || !ctable) {
587      /* free previously cached color table */
588      if (ctable)
589         _mesa_free(ctable);
590      /* Get the color table from X */
591      ctable = (XMesaColor *) MALLOC(cmapSize * sizeof(XMesaColor));
592      assert(ctable);
593      for (i = 0; i < cmapSize; i++) {
594         ctable[i].pixel = i;
595      }
596      XQueryColors(dpy, cmap, ctable, cmapSize);
597      prevDisplay = dpy;
598      prevCmap = cmap;
599      prevCmapSize = cmapSize;
600   }
601#endif
602
603   /* Find best match. */
604   bestmatch = -1;
605   mindist = 0.0;
606   for (i = 0; i < cmapSize; i++) {
607      double dr = 0.30 * ((double) color->red - (double) ctable[i].red);
608      double dg = 0.59 * ((double) color->green - (double) ctable[i].green);
609      double db = 0.11 * ((double) color->blue - (double) ctable[i].blue);
610      double dist = dr * dr + dg * dg + db * db;
611      if (bestmatch < 0 || dist < mindist) {
612         bestmatch = i;
613         mindist = dist;
614      }
615   }
616
617   /* Return result. */
618   subColor.red   = ctable[bestmatch].red;
619   subColor.green = ctable[bestmatch].green;
620   subColor.blue  = ctable[bestmatch].blue;
621   /* Try to allocate the closest match color.  This should only
622    * fail if the cell is read/write.  Otherwise, we're incrementing
623    * the cell's reference count.
624    */
625#ifdef XFree86Server
626   if (AllocColor(cmap,
627		  &subColor.red, &subColor.green, &subColor.blue,
628		  &subColor.pixel,
629		  client) == Success) {
630#else
631   if (XAllocColor(dpy, cmap, &subColor)) {
632#endif
633      *alloced = 1;
634   }
635   else {
636      /* do this to work around a problem reported by Frank Ortega */
637      subColor.pixel = (unsigned long) bestmatch;
638      subColor.red   = ctable[bestmatch].red;
639      subColor.green = ctable[bestmatch].green;
640      subColor.blue  = ctable[bestmatch].blue;
641      subColor.flags = DoRed | DoGreen | DoBlue;
642      *alloced = 0;
643   }
644#ifdef XFree86Server
645   _mesa_free(ppixIn);
646   _mesa_free(ctable);
647#else
648   /* don't free table, save it for next time */
649#endif
650
651   *color = subColor;
652   *exact = 0;
653}
654
655
656
657/**
658 * Do setup for PF_GRAYSCALE pixel format.
659 * Note that buffer may be NULL.
660 */
661static GLboolean
662setup_grayscale(int client, XMesaVisual v,
663                XMesaBuffer buffer, XMesaColormap cmap)
664{
665   if (GET_VISUAL_DEPTH(v)<4 || GET_VISUAL_DEPTH(v)>16) {
666      return GL_FALSE;
667   }
668
669   if (buffer) {
670      XMesaBuffer prevBuffer;
671
672      if (!cmap) {
673         return GL_FALSE;
674      }
675
676      prevBuffer = xmesa_find_buffer(v->display, cmap, buffer);
677      if (prevBuffer &&
678          (buffer->xm_visual->mesa_visual.rgbMode ==
679           prevBuffer->xm_visual->mesa_visual.rgbMode)) {
680         /* Copy colormap stuff from previous XMesaBuffer which uses same
681          * X colormap.  Do this to avoid time spent in noFaultXAllocColor.
682          */
683         copy_colortable_info(buffer, prevBuffer);
684      }
685      else {
686         /* Allocate 256 shades of gray */
687         int gray;
688         int colorsfailed = 0;
689         for (gray=0;gray<256;gray++) {
690            GLint r = gamma_adjust( v->RedGamma,   gray, 255 );
691            GLint g = gamma_adjust( v->GreenGamma, gray, 255 );
692            GLint b = gamma_adjust( v->BlueGamma,  gray, 255 );
693            int exact, alloced;
694            XMesaColor xcol;
695            xcol.red   = (r << 8) | r;
696            xcol.green = (g << 8) | g;
697            xcol.blue  = (b << 8) | b;
698            noFaultXAllocColor( client, v->display,
699                                cmap, GET_COLORMAP_SIZE(v),
700                                &xcol, &exact, &alloced );
701            if (!exact) {
702               colorsfailed++;
703            }
704            if (alloced) {
705               assert(buffer->num_alloced<256);
706               buffer->alloced_colors[buffer->num_alloced] = xcol.pixel;
707               buffer->num_alloced++;
708            }
709
710            /*OLD
711            assert(gray < 576);
712            buffer->color_table[gray*3+0] = xcol.pixel;
713            buffer->color_table[gray*3+1] = xcol.pixel;
714            buffer->color_table[gray*3+2] = xcol.pixel;
715            assert(xcol.pixel < 65536);
716            buffer->pixel_to_r[xcol.pixel] = gray * 30 / 100;
717            buffer->pixel_to_g[xcol.pixel] = gray * 59 / 100;
718            buffer->pixel_to_b[xcol.pixel] = gray * 11 / 100;
719            */
720            buffer->color_table[gray] = xcol.pixel;
721            assert(xcol.pixel < 65536);
722            buffer->pixel_to_r[xcol.pixel] = gray;
723            buffer->pixel_to_g[xcol.pixel] = gray;
724            buffer->pixel_to_b[xcol.pixel] = gray;
725         }
726
727         if (colorsfailed && _mesa_getenv("MESA_DEBUG")) {
728            _mesa_warning(NULL,
729                  "Note: %d out of 256 needed colors do not match exactly.\n",
730                  colorsfailed );
731         }
732      }
733   }
734
735   v->dithered_pf = PF_Grayscale;
736   v->undithered_pf = PF_Grayscale;
737   return GL_TRUE;
738}
739
740
741
742/**
743 * Setup RGB rendering for a window with a PseudoColor, StaticColor,
744 * or 8-bit TrueColor visual visual.  We try to allocate a palette of 225
745 * colors (5 red, 9 green, 5 blue) and dither to approximate a 24-bit RGB
746 * color.  While this function was originally designed just for 8-bit
747 * visuals, it has also proven to work from 4-bit up to 16-bit visuals.
748 * Dithering code contributed by Bob Mercier.
749 */
750static GLboolean
751setup_dithered_color(int client, XMesaVisual v,
752                     XMesaBuffer buffer, XMesaColormap cmap)
753{
754   if (GET_VISUAL_DEPTH(v)<4 || GET_VISUAL_DEPTH(v)>16) {
755      return GL_FALSE;
756   }
757
758   if (buffer) {
759      XMesaBuffer prevBuffer;
760
761      if (!cmap) {
762         return GL_FALSE;
763      }
764
765      prevBuffer = xmesa_find_buffer(v->display, cmap, buffer);
766      if (prevBuffer &&
767          (buffer->xm_visual->mesa_visual.rgbMode ==
768           prevBuffer->xm_visual->mesa_visual.rgbMode)) {
769         /* Copy colormap stuff from previous, matching XMesaBuffer.
770          * Do this to avoid time spent in noFaultXAllocColor.
771          */
772         copy_colortable_info(buffer, prevBuffer);
773      }
774      else {
775         /* Allocate X colors and initialize color_table[], red_table[], etc */
776         int r, g, b, i;
777         int colorsfailed = 0;
778         for (r = 0; r < DITH_R; r++) {
779            for (g = 0; g < DITH_G; g++) {
780               for (b = 0; b < DITH_B; b++) {
781                  XMesaColor xcol;
782                  int exact, alloced;
783                  xcol.red  =gamma_adjust(v->RedGamma,   r*65535/(DITH_R-1),65535);
784                  xcol.green=gamma_adjust(v->GreenGamma, g*65535/(DITH_G-1),65535);
785                  xcol.blue =gamma_adjust(v->BlueGamma,  b*65535/(DITH_B-1),65535);
786                  noFaultXAllocColor( client, v->display,
787                                      cmap, GET_COLORMAP_SIZE(v),
788                                      &xcol, &exact, &alloced );
789                  if (!exact) {
790                     colorsfailed++;
791                  }
792                  if (alloced) {
793                     assert(buffer->num_alloced<256);
794                     buffer->alloced_colors[buffer->num_alloced] = xcol.pixel;
795                     buffer->num_alloced++;
796                  }
797                  i = DITH_MIX( r, g, b );
798                  assert(i < 576);
799                  buffer->color_table[i] = xcol.pixel;
800                  assert(xcol.pixel < 65536);
801                  buffer->pixel_to_r[xcol.pixel] = r * 255 / (DITH_R-1);
802                  buffer->pixel_to_g[xcol.pixel] = g * 255 / (DITH_G-1);
803                  buffer->pixel_to_b[xcol.pixel] = b * 255 / (DITH_B-1);
804               }
805            }
806         }
807
808         if (colorsfailed && _mesa_getenv("MESA_DEBUG")) {
809            _mesa_warning(NULL,
810                  "Note: %d out of %d needed colors do not match exactly.\n",
811                  colorsfailed, DITH_R * DITH_G * DITH_B );
812         }
813      }
814   }
815
816   v->dithered_pf = PF_Dither;
817   v->undithered_pf = PF_Lookup;
818   return GL_TRUE;
819}
820
821
822/**
823 * Setup for Hewlett Packard Color Recovery 8-bit TrueColor mode.
824 * HPCR simulates 24-bit color fidelity with an 8-bit frame buffer.
825 * Special dithering tables have to be initialized.
826 */
827static void
828setup_8bit_hpcr(XMesaVisual v)
829{
830   /* HP Color Recovery contributed by:  Alex De Bruyn (ad@lms.be)
831    * To work properly, the atom _HP_RGB_SMOOTH_MAP_LIST must be defined
832    * on the root window AND the colormap obtainable by XGetRGBColormaps
833    * for that atom must be set on the window.  (see also tkInitWindow)
834    * If that colormap is not set, the output will look stripy.
835    */
836
837   /* Setup color tables with gamma correction */
838   int i;
839   double g;
840
841   g = 1.0 / v->RedGamma;
842   for (i=0; i<256; i++) {
843      GLint red = IROUND_POS(255.0 * _mesa_pow( hpcr_rgbTbl[0][i]/255.0, g ));
844      v->hpcr_rgbTbl[0][i] = CLAMP( red, 16, 239 );
845   }
846
847   g = 1.0 / v->GreenGamma;
848   for (i=0; i<256; i++) {
849      GLint green = IROUND_POS(255.0 * _mesa_pow( hpcr_rgbTbl[1][i]/255.0, g ));
850      v->hpcr_rgbTbl[1][i] = CLAMP( green, 16, 239 );
851   }
852
853   g = 1.0 / v->BlueGamma;
854   for (i=0; i<256; i++) {
855      GLint blue = IROUND_POS(255.0 * _mesa_pow( hpcr_rgbTbl[2][i]/255.0, g ));
856      v->hpcr_rgbTbl[2][i] = CLAMP( blue, 32, 223 );
857   }
858   v->undithered_pf = PF_HPCR;  /* can't really disable dithering for now */
859   v->dithered_pf = PF_HPCR;
860
861   /* which method should I use to clear */
862   /* GL_FALSE: keep the ordinary method  */
863   /* GL_TRUE : clear with dither pattern */
864   v->hpcr_clear_flag = _mesa_getenv("MESA_HPCR_CLEAR") ? GL_TRUE : GL_FALSE;
865
866   if (v->hpcr_clear_flag) {
867      v->hpcr_clear_pixmap = XMesaCreatePixmap(v->display,
868                                               DefaultRootWindow(v->display),
869                                               16, 2, 8);
870#ifndef XFree86Server
871      v->hpcr_clear_ximage = XGetImage(v->display, v->hpcr_clear_pixmap,
872                                       0, 0, 16, 2, AllPlanes, ZPixmap);
873#endif
874   }
875}
876
877
878/**
879 * Setup RGB rendering for a window with a True/DirectColor visual.
880 */
881static void
882setup_truecolor(XMesaVisual v, XMesaBuffer buffer, XMesaColormap cmap)
883{
884   unsigned long rmask, gmask, bmask;
885   (void) buffer;
886   (void) cmap;
887
888   /* Compute red multiplier (mask) and bit shift */
889   v->rshift = 0;
890   rmask = GET_REDMASK(v);
891   while ((rmask & 1)==0) {
892      v->rshift++;
893      rmask = rmask >> 1;
894   }
895
896   /* Compute green multiplier (mask) and bit shift */
897   v->gshift = 0;
898   gmask = GET_GREENMASK(v);
899   while ((gmask & 1)==0) {
900      v->gshift++;
901      gmask = gmask >> 1;
902   }
903
904   /* Compute blue multiplier (mask) and bit shift */
905   v->bshift = 0;
906   bmask = GET_BLUEMASK(v);
907   while ((bmask & 1)==0) {
908      v->bshift++;
909      bmask = bmask >> 1;
910   }
911
912   /*
913    * Compute component-to-pixel lookup tables and dithering kernel
914    */
915   {
916      static GLubyte kernel[16] = {
917          0*16,  8*16,  2*16, 10*16,
918         12*16,  4*16, 14*16,  6*16,
919          3*16, 11*16,  1*16,  9*16,
920         15*16,  7*16, 13*16,  5*16,
921      };
922      GLint rBits = _mesa_bitcount(rmask);
923      GLint gBits = _mesa_bitcount(gmask);
924      GLint bBits = _mesa_bitcount(bmask);
925      GLint maxBits;
926      GLuint i;
927
928      /* convert pixel components in [0,_mask] to RGB values in [0,255] */
929      for (i=0; i<=rmask; i++)
930         v->PixelToR[i] = (unsigned char) ((i * 255) / rmask);
931      for (i=0; i<=gmask; i++)
932         v->PixelToG[i] = (unsigned char) ((i * 255) / gmask);
933      for (i=0; i<=bmask; i++)
934         v->PixelToB[i] = (unsigned char) ((i * 255) / bmask);
935
936      /* convert RGB values from [0,255] to pixel components */
937
938      for (i=0;i<256;i++) {
939         GLint r = gamma_adjust(v->RedGamma,   i, 255);
940         GLint g = gamma_adjust(v->GreenGamma, i, 255);
941         GLint b = gamma_adjust(v->BlueGamma,  i, 255);
942         v->RtoPixel[i] = (r >> (8-rBits)) << v->rshift;
943         v->GtoPixel[i] = (g >> (8-gBits)) << v->gshift;
944         v->BtoPixel[i] = (b >> (8-bBits)) << v->bshift;
945      }
946      /* overflow protection */
947      for (i=256;i<512;i++) {
948         v->RtoPixel[i] = v->RtoPixel[255];
949         v->GtoPixel[i] = v->GtoPixel[255];
950         v->BtoPixel[i] = v->BtoPixel[255];
951      }
952
953      /* setup dithering kernel */
954      maxBits = rBits;
955      if (gBits > maxBits)  maxBits = gBits;
956      if (bBits > maxBits)  maxBits = bBits;
957      for (i=0;i<16;i++) {
958         v->Kernel[i] = kernel[i] >> maxBits;
959      }
960
961      v->undithered_pf = PF_Truecolor;
962      v->dithered_pf = (GET_VISUAL_DEPTH(v)<24) ? PF_Dither_True : PF_Truecolor;
963   }
964
965   /*
966    * Now check for TrueColor visuals which we can optimize.
967    */
968   if (   GET_REDMASK(v)  ==0x0000ff
969       && GET_GREENMASK(v)==0x00ff00
970       && GET_BLUEMASK(v) ==0xff0000
971       && CHECK_BYTE_ORDER(v)
972       && v->BitsPerPixel==32
973       && v->RedGamma==1.0 && v->GreenGamma==1.0 && v->BlueGamma==1.0) {
974      /* common 32 bpp config used on SGI, Sun */
975      v->undithered_pf = v->dithered_pf = PF_8A8B8G8R; /* ABGR */
976   }
977   else if (GET_REDMASK(v)  == 0xff0000
978         && GET_GREENMASK(v)== 0x00ff00
979         && GET_BLUEMASK(v) == 0x0000ff
980         && CHECK_BYTE_ORDER(v)
981         && v->RedGamma == 1.0 && v->GreenGamma == 1.0 && v->BlueGamma == 1.0){
982      if (v->BitsPerPixel==32) {
983         /* if 32 bpp, and visual indicates 8 bpp alpha channel */
984         if (GET_VISUAL_DEPTH(v) == 32 && v->mesa_visual.alphaBits == 8)
985            v->undithered_pf = v->dithered_pf = PF_8A8R8G8B; /* ARGB */
986         else
987            v->undithered_pf = v->dithered_pf = PF_8R8G8B; /* xRGB */
988      }
989      else if (v->BitsPerPixel == 24) {
990         v->undithered_pf = v->dithered_pf = PF_8R8G8B24; /* RGB */
991      }
992   }
993   else if (GET_REDMASK(v)  ==0xf800
994       &&   GET_GREENMASK(v)==0x07e0
995       &&   GET_BLUEMASK(v) ==0x001f
996       && CHECK_BYTE_ORDER(v)
997       && v->BitsPerPixel==16
998       && v->RedGamma==1.0 && v->GreenGamma==1.0 && v->BlueGamma==1.0) {
999      /* 5-6-5 RGB */
1000      v->undithered_pf = PF_5R6G5B;
1001      v->dithered_pf = PF_Dither_5R6G5B;
1002   }
1003   else if (GET_REDMASK(v)  ==0xe0
1004       &&   GET_GREENMASK(v)==0x1c
1005       &&   GET_BLUEMASK(v) ==0x03
1006       && CHECK_FOR_HPCR(v)) {
1007      /* 8-bit HP color recovery */
1008      setup_8bit_hpcr( v );
1009   }
1010}
1011
1012
1013
1014/**
1015 * Setup RGB rendering for a window with a monochrome visual.
1016 */
1017static void
1018setup_monochrome( XMesaVisual v, XMesaBuffer b )
1019{
1020   (void) b;
1021   v->dithered_pf = v->undithered_pf = PF_1Bit;
1022   /* if black=1 then we must flip pixel values */
1023   v->bitFlip = (GET_BLACK_PIXEL(v) != 0);
1024}
1025
1026
1027
1028/**
1029 * When a context is bound for the first time, we can finally finish
1030 * initializing the context's visual and buffer information.
1031 * \param v  the XMesaVisual to initialize
1032 * \param b  the XMesaBuffer to initialize (may be NULL)
1033 * \param rgb_flag  TRUE = RGBA mode, FALSE = color index mode
1034 * \param window  the window/pixmap we're rendering into
1035 * \param cmap  the colormap associated with the window/pixmap
1036 * \return GL_TRUE=success, GL_FALSE=failure
1037 */
1038static GLboolean
1039initialize_visual_and_buffer(int client, XMesaVisual v, XMesaBuffer b,
1040                             GLboolean rgb_flag, XMesaDrawable window,
1041                             XMesaColormap cmap)
1042{
1043   ASSERT(!b || b->xm_visual == v);
1044
1045   /* Save true bits/pixel */
1046   v->BitsPerPixel = bits_per_pixel(v);
1047   assert(v->BitsPerPixel > 0);
1048
1049   if (rgb_flag == GL_FALSE) {
1050      /* COLOR-INDEXED WINDOW:
1051       * Even if the visual is TrueColor or DirectColor we treat it as
1052       * being color indexed.  This is weird but might be useful to someone.
1053       */
1054      v->dithered_pf = v->undithered_pf = PF_Index;
1055      v->mesa_visual.indexBits = GET_VISUAL_DEPTH(v);
1056   }
1057   else {
1058      /* RGB WINDOW:
1059       * We support RGB rendering into almost any kind of visual.
1060       */
1061      const int xclass = v->mesa_visual.visualType;
1062      if (xclass == GLX_TRUE_COLOR || xclass == GLX_DIRECT_COLOR) {
1063	 setup_truecolor( v, b, cmap );
1064      }
1065      else if (xclass == GLX_STATIC_GRAY && GET_VISUAL_DEPTH(v) == 1) {
1066	 setup_monochrome( v, b );
1067      }
1068      else if (xclass == GLX_GRAY_SCALE || xclass == GLX_STATIC_GRAY) {
1069         if (!setup_grayscale( client, v, b, cmap )) {
1070            return GL_FALSE;
1071         }
1072      }
1073      else if ((xclass == GLX_PSEUDO_COLOR || xclass == GLX_STATIC_COLOR)
1074               && GET_VISUAL_DEPTH(v)>=4 && GET_VISUAL_DEPTH(v)<=16) {
1075	 if (!setup_dithered_color( client, v, b, cmap )) {
1076            return GL_FALSE;
1077         }
1078      }
1079      else {
1080	 _mesa_warning(NULL, "XMesa: RGB mode rendering not supported in given visual.\n");
1081	 return GL_FALSE;
1082      }
1083      v->mesa_visual.indexBits = 0;
1084
1085      if (_mesa_getenv("MESA_NO_DITHER")) {
1086	 v->dithered_pf = v->undithered_pf;
1087      }
1088   }
1089
1090
1091   /*
1092    * If MESA_INFO env var is set print out some debugging info
1093    * which can help Brian figure out what's going on when a user
1094    * reports bugs.
1095    */
1096   if (_mesa_getenv("MESA_INFO")) {
1097      _mesa_printf("X/Mesa visual = %p\n", (void *) v);
1098      _mesa_printf("X/Mesa dithered pf = %u\n", v->dithered_pf);
1099      _mesa_printf("X/Mesa undithered pf = %u\n", v->undithered_pf);
1100      _mesa_printf("X/Mesa level = %d\n", v->mesa_visual.level);
1101      _mesa_printf("X/Mesa depth = %d\n", GET_VISUAL_DEPTH(v));
1102      _mesa_printf("X/Mesa bits per pixel = %d\n", v->BitsPerPixel);
1103   }
1104
1105   if (b && window) {
1106      /* Do window-specific initializations */
1107
1108      /* these should have been set in create_xmesa_buffer */
1109      ASSERT(b->frontxrb->drawable == window);
1110      ASSERT(b->frontxrb->pixmap == (XMesaPixmap) window);
1111
1112      /* Setup for single/double buffering */
1113      if (v->mesa_visual.doubleBufferMode) {
1114         /* Double buffered */
1115         b->shm = check_for_xshm( v->display );
1116      }
1117
1118      /* X11 graphics contexts */
1119#ifdef XFree86Server
1120      b->gc = CreateScratchGC(v->display, window->depth);
1121#else
1122      b->gc = XCreateGC( v->display, window, 0, NULL );
1123#endif
1124      XMesaSetFunction( v->display, b->gc, GXcopy );
1125
1126      /* cleargc - for glClear() */
1127#ifdef XFree86Server
1128      b->cleargc = CreateScratchGC(v->display, window->depth);
1129#else
1130      b->cleargc = XCreateGC( v->display, window, 0, NULL );
1131#endif
1132      XMesaSetFunction( v->display, b->cleargc, GXcopy );
1133
1134      /*
1135       * Don't generate Graphics Expose/NoExpose events in swapbuffers().
1136       * Patch contributed by Michael Pichler May 15, 1995.
1137       */
1138#ifdef XFree86Server
1139      b->swapgc = CreateScratchGC(v->display, window->depth);
1140      {
1141         CARD32 v[1];
1142         v[0] = FALSE;
1143         dixChangeGC(NullClient, b->swapgc, GCGraphicsExposures, v, NULL);
1144      }
1145#else
1146      {
1147         XGCValues gcvalues;
1148         gcvalues.graphics_exposures = False;
1149         b->swapgc = XCreateGC(v->display, window,
1150                               GCGraphicsExposures, &gcvalues);
1151      }
1152#endif
1153      XMesaSetFunction( v->display, b->swapgc, GXcopy );
1154      /*
1155       * Set fill style and tile pixmap once for all for HPCR stuff
1156       * (instead of doing it each time in clear_color_HPCR_pixmap())
1157       * Initialize whole stuff
1158       * Patch contributed by Jacques Leroy March 8, 1998.
1159       */
1160      if (v->hpcr_clear_flag && b->backxrb && b->backxrb->pixmap) {
1161         int i;
1162         for (i = 0; i < 16; i++) {
1163            XMesaPutPixel(v->hpcr_clear_ximage, i, 0, 0);
1164            XMesaPutPixel(v->hpcr_clear_ximage, i, 1, 0);
1165         }
1166         XMesaPutImage(b->display, (XMesaDrawable) v->hpcr_clear_pixmap,
1167                       b->cleargc, v->hpcr_clear_ximage, 0, 0, 0, 0, 16, 2);
1168         XMesaSetFillStyle( v->display, b->cleargc, FillTiled);
1169         XMesaSetTile( v->display, b->cleargc, v->hpcr_clear_pixmap );
1170      }
1171
1172      /* Initialize the row buffer XImage for use in write_color_span() */
1173#ifdef XFree86Server
1174      b->rowimage = XMesaCreateImage(GET_VISUAL_DEPTH(v), MAX_WIDTH, 1,
1175				     (char *)MALLOC(MAX_WIDTH*4));
1176#else
1177      b->rowimage = XCreateImage( v->display,
1178                                  v->visinfo->visual,
1179                                  v->visinfo->depth,
1180                                  ZPixmap, 0,           /*format, offset*/
1181                                  (char*) MALLOC(MAX_WIDTH*4),  /*data*/
1182                                  MAX_WIDTH, 1,         /*width, height*/
1183                                  32,                   /*bitmap_pad*/
1184                                  0                     /*bytes_per_line*/ );
1185#endif
1186      if (!b->rowimage)
1187         return GL_FALSE;
1188   }
1189
1190   return GL_TRUE;
1191}
1192
1193
1194
1195/*
1196 * Convert an RGBA color to a pixel value.
1197 */
1198unsigned long
1199xmesa_color_to_pixel(GLcontext *ctx,
1200                     GLubyte r, GLubyte g, GLubyte b, GLubyte a,
1201                     GLuint pixelFormat)
1202{
1203   XMesaContext xmesa = XMESA_CONTEXT(ctx);
1204   switch (pixelFormat) {
1205      case PF_Index:
1206         return 0;
1207      case PF_Truecolor:
1208         {
1209            unsigned long p;
1210            PACK_TRUECOLOR( p, r, g, b );
1211            return p;
1212         }
1213      case PF_8A8B8G8R:
1214         return PACK_8A8B8G8R( r, g, b, a );
1215      case PF_8A8R8G8B:
1216         return PACK_8A8R8G8B( r, g, b, a );
1217      case PF_8R8G8B:
1218         /* fall through */
1219      case PF_8R8G8B24:
1220         return PACK_8R8G8B( r, g, b );
1221      case PF_5R6G5B:
1222         return PACK_5R6G5B( r, g, b );
1223      case PF_Dither:
1224         {
1225            DITHER_SETUP;
1226            return DITHER( 1, 0, r, g, b );
1227         }
1228      case PF_1Bit:
1229         /* 382 = (3*255)/2 */
1230         return ((r+g+b) > 382) ^ xmesa->xm_visual->bitFlip;
1231      case PF_HPCR:
1232         return DITHER_HPCR(1, 1, r, g, b);
1233      case PF_Lookup:
1234         {
1235            LOOKUP_SETUP;
1236            return LOOKUP( r, g, b );
1237         }
1238      case PF_Grayscale:
1239         return GRAY_RGB( r, g, b );
1240      case PF_Dither_True:
1241         /* fall through */
1242      case PF_Dither_5R6G5B:
1243         {
1244            unsigned long p;
1245            PACK_TRUEDITHER(p, 1, 0, r, g, b);
1246            return p;
1247         }
1248      default:
1249         _mesa_problem(ctx, "Bad pixel format in xmesa_color_to_pixel");
1250   }
1251   return 0;
1252}
1253
1254
1255#define NUM_VISUAL_TYPES   6
1256
1257/**
1258 * Convert an X visual type to a GLX visual type.
1259 *
1260 * \param visualType X visual type (i.e., \c TrueColor, \c StaticGray, etc.)
1261 *        to be converted.
1262 * \return If \c visualType is a valid X visual type, a GLX visual type will
1263 *         be returned.  Otherwise \c GLX_NONE will be returned.
1264 *
1265 * \note
1266 * This code was lifted directly from lib/GL/glx/glcontextmodes.c in the
1267 * DRI CVS tree.
1268 */
1269static GLint
1270xmesa_convert_from_x_visual_type( int visualType )
1271{
1272    static const int glx_visual_types[ NUM_VISUAL_TYPES ] = {
1273	GLX_STATIC_GRAY,  GLX_GRAY_SCALE,
1274	GLX_STATIC_COLOR, GLX_PSEUDO_COLOR,
1275	GLX_TRUE_COLOR,   GLX_DIRECT_COLOR
1276    };
1277
1278    return ( (unsigned) visualType < NUM_VISUAL_TYPES )
1279	? glx_visual_types[ visualType ] : GLX_NONE;
1280}
1281
1282
1283/**********************************************************************/
1284/*****                       Public Functions                     *****/
1285/**********************************************************************/
1286
1287
1288/*
1289 * Create a new X/Mesa visual.
1290 * Input:  display - X11 display
1291 *         visinfo - an XVisualInfo pointer
1292 *         rgb_flag - GL_TRUE = RGB mode,
1293 *                    GL_FALSE = color index mode
1294 *         alpha_flag - alpha buffer requested?
1295 *         db_flag - GL_TRUE = double-buffered,
1296 *                   GL_FALSE = single buffered
1297 *         stereo_flag - stereo visual?
1298 *         ximage_flag - GL_TRUE = use an XImage for back buffer,
1299 *                       GL_FALSE = use an off-screen pixmap for back buffer
1300 *         depth_size - requested bits/depth values, or zero
1301 *         stencil_size - requested bits/stencil values, or zero
1302 *         accum_red_size - requested bits/red accum values, or zero
1303 *         accum_green_size - requested bits/green accum values, or zero
1304 *         accum_blue_size - requested bits/blue accum values, or zero
1305 *         accum_alpha_size - requested bits/alpha accum values, or zero
1306 *         num_samples - number of samples/pixel if multisampling, or zero
1307 *         level - visual level, usually 0
1308 *         visualCaveat - ala the GLX extension, usually GLX_NONE
1309 * Return;  a new XMesaVisual or 0 if error.
1310 */
1311XMesaVisual XMesaCreateVisual( XMesaDisplay *display,
1312                               XMesaVisualInfo visinfo,
1313                               GLboolean rgb_flag,
1314                               GLboolean alpha_flag,
1315                               GLboolean db_flag,
1316                               GLboolean stereo_flag,
1317                               GLboolean ximage_flag,
1318                               GLint depth_size,
1319                               GLint stencil_size,
1320                               GLint accum_red_size,
1321                               GLint accum_green_size,
1322                               GLint accum_blue_size,
1323                               GLint accum_alpha_size,
1324                               GLint num_samples,
1325                               GLint level,
1326                               GLint visualCaveat )
1327{
1328   char *gamma;
1329   XMesaVisual v;
1330   GLint red_bits, green_bits, blue_bits, alpha_bits;
1331
1332#ifndef XFree86Server
1333   /* For debugging only */
1334   if (_mesa_getenv("MESA_XSYNC")) {
1335      /* This makes debugging X easier.
1336       * In your debugger, set a breakpoint on _XError to stop when an
1337       * X protocol error is generated.
1338       */
1339      XSynchronize( display, 1 );
1340   }
1341#endif
1342
1343   v = (XMesaVisual) CALLOC_STRUCT(xmesa_visual);
1344   if (!v) {
1345      return NULL;
1346   }
1347
1348   v->display = display;
1349
1350   /* Save a copy of the XVisualInfo struct because the user may X_mesa_free()
1351    * the struct but we may need some of the information contained in it
1352    * at a later time.
1353    */
1354#ifndef XFree86Server
1355   v->visinfo = (XVisualInfo *) MALLOC(sizeof(*visinfo));
1356   if(!v->visinfo) {
1357      _mesa_free(v);
1358      return NULL;
1359   }
1360   MEMCPY(v->visinfo, visinfo, sizeof(*visinfo));
1361#endif
1362
1363   /* check for MESA_GAMMA environment variable */
1364   gamma = _mesa_getenv("MESA_GAMMA");
1365   if (gamma) {
1366      v->RedGamma = v->GreenGamma = v->BlueGamma = 0.0;
1367      sscanf( gamma, "%f %f %f", &v->RedGamma, &v->GreenGamma, &v->BlueGamma );
1368      if (v->RedGamma<=0.0)    v->RedGamma = 1.0;
1369      if (v->GreenGamma<=0.0)  v->GreenGamma = v->RedGamma;
1370      if (v->BlueGamma<=0.0)   v->BlueGamma = v->RedGamma;
1371   }
1372   else {
1373      v->RedGamma = v->GreenGamma = v->BlueGamma = 1.0;
1374   }
1375
1376   v->ximage_flag = ximage_flag;
1377
1378#ifdef XFree86Server
1379   /* We could calculate these values by ourselves.  nplanes is either the sum
1380    * of the red, green, and blue bits or the number index bits.
1381    * ColormapEntries is either (1U << index_bits) or
1382    * (1U << max(redBits, greenBits, blueBits)).
1383    */
1384   assert(visinfo->nplanes > 0);
1385   v->nplanes = visinfo->nplanes;
1386   v->ColormapEntries = visinfo->ColormapEntries;
1387
1388   v->mesa_visual.redMask = visinfo->redMask;
1389   v->mesa_visual.greenMask = visinfo->greenMask;
1390   v->mesa_visual.blueMask = visinfo->blueMask;
1391   v->mesa_visual.visualID = visinfo->vid;
1392   v->mesa_visual.screen = 0; /* FIXME: What should be done here? */
1393#else
1394   v->mesa_visual.redMask = visinfo->red_mask;
1395   v->mesa_visual.greenMask = visinfo->green_mask;
1396   v->mesa_visual.blueMask = visinfo->blue_mask;
1397   v->mesa_visual.visualID = visinfo->visualid;
1398   v->mesa_visual.screen = visinfo->screen;
1399#endif
1400
1401#if defined(XFree86Server) || !(defined(__cplusplus) || defined(c_plusplus))
1402   v->mesa_visual.visualType = xmesa_convert_from_x_visual_type(visinfo->class);
1403#else
1404   v->mesa_visual.visualType = xmesa_convert_from_x_visual_type(visinfo->c_class);
1405#endif
1406
1407   v->mesa_visual.visualRating = visualCaveat;
1408
1409   if (alpha_flag)
1410      v->mesa_visual.alphaBits = 8;
1411
1412   (void) initialize_visual_and_buffer( 0, v, NULL, rgb_flag, 0, 0 );
1413
1414   {
1415      const int xclass = v->mesa_visual.visualType;
1416      if (xclass == GLX_TRUE_COLOR || xclass == GLX_DIRECT_COLOR) {
1417         red_bits   = _mesa_bitcount(GET_REDMASK(v));
1418         green_bits = _mesa_bitcount(GET_GREENMASK(v));
1419         blue_bits  = _mesa_bitcount(GET_BLUEMASK(v));
1420      }
1421      else {
1422         /* this is an approximation */
1423         int depth;
1424         depth = GET_VISUAL_DEPTH(v);
1425         red_bits = depth / 3;
1426         depth -= red_bits;
1427         green_bits = depth / 2;
1428         depth -= green_bits;
1429         blue_bits = depth;
1430         alpha_bits = 0;
1431         assert( red_bits + green_bits + blue_bits == GET_VISUAL_DEPTH(v) );
1432      }
1433      alpha_bits = v->mesa_visual.alphaBits;
1434   }
1435
1436   _mesa_initialize_visual( &v->mesa_visual,
1437                            rgb_flag, db_flag, stereo_flag,
1438                            red_bits, green_bits,
1439                            blue_bits, alpha_bits,
1440                            v->mesa_visual.indexBits,
1441                            depth_size,
1442                            stencil_size,
1443                            accum_red_size, accum_green_size,
1444                            accum_blue_size, accum_alpha_size,
1445                            0 );
1446
1447   /* XXX minor hack */
1448   v->mesa_visual.level = level;
1449   return v;
1450}
1451
1452
1453void XMesaDestroyVisual( XMesaVisual v )
1454{
1455#ifndef XFree86Server
1456   _mesa_free(v->visinfo);
1457#endif
1458   _mesa_free(v);
1459}
1460
1461
1462
1463/**
1464 * Create a new XMesaContext.
1465 * \param v  the XMesaVisual
1466 * \param share_list  another XMesaContext with which to share display
1467 *                    lists or NULL if no sharing is wanted.
1468 * \return an XMesaContext or NULL if error.
1469 */
1470XMesaContext XMesaCreateContext( XMesaVisual v, XMesaContext share_list )
1471{
1472   static GLboolean firstTime = GL_TRUE;
1473   XMesaContext c;
1474   GLcontext *mesaCtx;
1475   struct dd_function_table functions;
1476   TNLcontext *tnl;
1477
1478   if (firstTime) {
1479      _glthread_INIT_MUTEX(_xmesa_lock);
1480      firstTime = GL_FALSE;
1481   }
1482
1483   /* Note: the XMesaContext contains a Mesa GLcontext struct (inheritance) */
1484   c = (XMesaContext) CALLOC_STRUCT(xmesa_context);
1485   if (!c)
1486      return NULL;
1487
1488   mesaCtx = &(c->mesa);
1489
1490   /* initialize with default driver functions, then plug in XMesa funcs */
1491   _mesa_init_driver_functions(&functions);
1492   xmesa_init_driver_functions(v, &functions);
1493   if (!_mesa_initialize_context(mesaCtx, &v->mesa_visual,
1494                      share_list ? &(share_list->mesa) : (GLcontext *) NULL,
1495                      &functions, (void *) c)) {
1496      _mesa_free(c);
1497      return NULL;
1498   }
1499
1500   _mesa_enable_sw_extensions(mesaCtx);
1501   _mesa_enable_1_3_extensions(mesaCtx);
1502   _mesa_enable_1_4_extensions(mesaCtx);
1503   _mesa_enable_1_5_extensions(mesaCtx);
1504   _mesa_enable_2_0_extensions(mesaCtx);
1505#if ENABLE_EXT_texure_compression_s3tc
1506    if (c->Mesa_DXTn) {
1507       _mesa_enable_extension(mesaCtx, "GL_EXT_texture_compression_s3tc");
1508       _mesa_enable_extension(mesaCtx, "GL_S3_s3tc");
1509    }
1510    _mesa_enable_extension(mesaCtx, "GL_3DFX_texture_compression_FXT1");
1511#endif
1512#if ENABLE_EXT_timer_query
1513    _mesa_enable_extension(mesaCtx, "GL_EXT_timer_query");
1514#endif
1515
1516#ifdef XFree86Server
1517   /* If we're running in the X server, do bounds checking to prevent
1518    * segfaults and server crashes!
1519    */
1520   mesaCtx->Const.CheckArrayBounds = GL_TRUE;
1521#endif
1522
1523   /* finish up xmesa context initializations */
1524   c->swapbytes = CHECK_BYTE_ORDER(v) ? GL_FALSE : GL_TRUE;
1525   c->xm_visual = v;
1526   c->xm_buffer = NULL;   /* set later by XMesaMakeCurrent */
1527   c->display = v->display;
1528   c->pixelformat = v->dithered_pf;      /* Dithering is enabled by default */
1529
1530   /* Initialize the software rasterizer and helper modules.
1531    */
1532   if (!_swrast_CreateContext( mesaCtx ) ||
1533       !_vbo_CreateContext( mesaCtx ) ||
1534       !_tnl_CreateContext( mesaCtx ) ||
1535       !_swsetup_CreateContext( mesaCtx )) {
1536      _mesa_free_context_data(&c->mesa);
1537      _mesa_free(c);
1538      return NULL;
1539   }
1540
1541   /* tnl setup */
1542   tnl = TNL_CONTEXT(mesaCtx);
1543   tnl->Driver.RunPipeline = _tnl_run_pipeline;
1544   /* swrast setup */
1545   xmesa_register_swrast_functions( mesaCtx );
1546   _swsetup_Wakeup(mesaCtx);
1547
1548   return c;
1549}
1550
1551
1552
1553void XMesaDestroyContext( XMesaContext c )
1554{
1555   GLcontext *mesaCtx = &c->mesa;
1556#ifdef FX
1557   XMesaBuffer xmbuf = XMESA_BUFFER(mesaCtx->DrawBuffer);
1558
1559   if (xmbuf && xmbuf->FXctx)
1560      fxMesaDestroyContext(xmbuf->FXctx);
1561#endif
1562   _swsetup_DestroyContext( mesaCtx );
1563   _swrast_DestroyContext( mesaCtx );
1564   _tnl_DestroyContext( mesaCtx );
1565   _vbo_DestroyContext( mesaCtx );
1566   _mesa_free_context_data( mesaCtx );
1567   _mesa_free( c );
1568}
1569
1570
1571
1572/**
1573 * Private function for creating an XMesaBuffer which corresponds to an
1574 * X window or pixmap.
1575 * \param v  the window's XMesaVisual
1576 * \param w  the window we're wrapping
1577 * \param c  context used to initialize the buffer if 3Dfx mode in use.
1578 * \return  new XMesaBuffer or NULL if error
1579 */
1580XMesaBuffer
1581XMesaCreateWindowBuffer2(XMesaVisual v, XMesaWindow w, XMesaContext c)
1582{
1583#ifndef XFree86Server
1584   XWindowAttributes attr;
1585#endif
1586#ifdef FX
1587   char *fxEnvVar;
1588#endif
1589   int client = 0;
1590   XMesaBuffer b;
1591   XMesaColormap cmap;
1592
1593   assert(v);
1594   assert(w);
1595   (void) c;
1596
1597   /* Check that window depth matches visual depth */
1598#ifdef XFree86Server
1599   client = CLIENT_ID(((XMesaDrawable)w)->id);
1600
1601   if (GET_VISUAL_DEPTH(v) != ((XMesaDrawable)w)->depth) {
1602      _mesa_warning(NULL, "XMesaCreateWindowBuffer: depth mismatch between visual (%d) and window (%d)!\n",
1603                    GET_VISUAL_DEPTH(v), ((XMesaDrawable) w)->depth);
1604      return NULL;
1605   }
1606#else
1607   XGetWindowAttributes( v->display, w, &attr );
1608
1609   if (GET_VISUAL_DEPTH(v) != attr.depth) {
1610      _mesa_warning(NULL, "XMesaCreateWindowBuffer: depth mismatch between visual (%d) and window (%d)!\n",
1611                    GET_VISUAL_DEPTH(v), attr.depth);
1612      return NULL;
1613   }
1614#endif
1615
1616   /* Find colormap */
1617#ifdef XFree86Server
1618   cmap = (ColormapPtr)LookupIDByType(wColormap(w), RT_COLORMAP);
1619#else
1620   if (attr.colormap) {
1621      cmap = attr.colormap;
1622   }
1623   else {
1624      _mesa_warning(NULL, "Window %u has no colormap!\n", (unsigned int) w);
1625      /* this is weird, a window w/out a colormap!? */
1626      /* OK, let's just allocate a new one and hope for the best */
1627      cmap = XCreateColormap(v->display, w, attr.visual, AllocNone);
1628   }
1629#endif
1630
1631   b = create_xmesa_buffer((XMesaDrawable) w, WINDOW, v, cmap);
1632   if (!b)
1633      return NULL;
1634
1635   if (!initialize_visual_and_buffer( client, v, b, v->mesa_visual.rgbMode,
1636                                      (XMesaDrawable) w, cmap )) {
1637      xmesa_free_buffer(b);
1638      return NULL;
1639   }
1640
1641#ifdef FX
1642   fxEnvVar = _mesa_getenv("MESA_GLX_FX");
1643   if (fxEnvVar) {
1644     if (fxEnvVar[0]!='d') {
1645       int attribs[100];
1646       int numAttribs = 0;
1647       int hw;
1648       if (v->mesa_visual.depthBits > 0) {
1649	 attribs[numAttribs++] = FXMESA_DEPTH_SIZE;
1650	 attribs[numAttribs++] = v->mesa_visual.depthBits;
1651       }
1652       if (v->mesa_visual.doubleBufferMode) {
1653	 attribs[numAttribs++] = FXMESA_DOUBLEBUFFER;
1654       }
1655       if (v->mesa_visual.accumRedBits > 0) {
1656	 attribs[numAttribs++] = FXMESA_ACCUM_SIZE;
1657	 attribs[numAttribs++] = v->mesa_visual.accumRedBits;
1658       }
1659       if (v->mesa_visual.stencilBits > 0) {
1660         attribs[numAttribs++] = FXMESA_STENCIL_SIZE;
1661         attribs[numAttribs++] = v->mesa_visual.stencilBits;
1662       }
1663       if (v->mesa_visual.alphaBits > 0) {
1664         attribs[numAttribs++] = FXMESA_ALPHA_SIZE;
1665         attribs[numAttribs++] = v->mesa_visual.alphaBits;
1666       }
1667       if (1) {
1668         attribs[numAttribs++] = FXMESA_SHARE_CONTEXT;
1669         attribs[numAttribs++] = (int) &(c->mesa);
1670       }
1671       attribs[numAttribs++] = FXMESA_NONE;
1672
1673       /* [dBorca] we should take an envvar for `fxMesaSelectCurrentBoard'!!! */
1674       hw = fxMesaSelectCurrentBoard(0);
1675
1676       /* if these fail, there's a new bug somewhere */
1677       ASSERT(b->mesa_buffer.Width > 0);
1678       ASSERT(b->mesa_buffer.Height > 0);
1679
1680       if ((hw == GR_SSTTYPE_VOODOO) || (hw == GR_SSTTYPE_Voodoo2)) {
1681         b->FXctx = fxMesaCreateBestContext(0, b->mesa_buffer.Width,
1682                                            b->mesa_buffer.Height, attribs);
1683         if ((v->undithered_pf!=PF_Index) && (b->backxrb->ximage)) {
1684	   b->FXisHackUsable = b->FXctx ? GL_TRUE : GL_FALSE;
1685	   if (b->FXctx && (fxEnvVar[0]=='w' || fxEnvVar[0]=='W')) {
1686	     b->FXwindowHack = GL_TRUE;
1687	     FX_grSstControl(GR_CONTROL_DEACTIVATE);
1688	   }
1689           else {
1690	     b->FXwindowHack = GL_FALSE;
1691	   }
1692         }
1693       }
1694       else {
1695         if (fxEnvVar[0]=='w' || fxEnvVar[0]=='W')
1696	   b->FXctx = fxMesaCreateContext(w, GR_RESOLUTION_NONE,
1697					  GR_REFRESH_75Hz, attribs);
1698         else
1699	   b->FXctx = fxMesaCreateBestContext(0, b->mesa_buffer.Width,
1700                                              b->mesa_buffer.Height, attribs);
1701         b->FXisHackUsable = GL_FALSE;
1702         b->FXwindowHack = GL_FALSE;
1703       }
1704       /*
1705       fprintf(stderr,
1706               "voodoo %d, wid %d height %d hack: usable %d active %d\n",
1707               hw, b->mesa_buffer.Width, b->mesa_buffer.Height,
1708	       b->FXisHackUsable, b->FXwindowHack);
1709       */
1710     }
1711   }
1712   else {
1713      _mesa_warning(NULL, "WARNING: This Mesa Library includes the Glide driver but\n");
1714      _mesa_warning(NULL, "         you have not defined the MESA_GLX_FX env. var.\n");
1715      _mesa_warning(NULL, "         (check the README.3DFX file for more information).\n\n");
1716      _mesa_warning(NULL, "         you can disable this message with a 'export MESA_GLX_FX=disable'.\n");
1717   }
1718#endif
1719
1720   return b;
1721}
1722
1723
1724XMesaBuffer
1725XMesaCreateWindowBuffer(XMesaVisual v, XMesaWindow w)
1726{
1727   return XMesaCreateWindowBuffer2( v, w, NULL );
1728}
1729
1730
1731/**
1732 * Create a new XMesaBuffer from an X pixmap.
1733 *
1734 * \param v    the XMesaVisual
1735 * \param p    the pixmap
1736 * \param cmap the colormap, may be 0 if using a \c GLX_TRUE_COLOR or
1737 *             \c GLX_DIRECT_COLOR visual for the pixmap
1738 * \returns new XMesaBuffer or NULL if error
1739 */
1740XMesaBuffer
1741XMesaCreatePixmapBuffer(XMesaVisual v, XMesaPixmap p, XMesaColormap cmap)
1742{
1743   int client = 0;
1744   XMesaBuffer b;
1745
1746   assert(v);
1747
1748   b = create_xmesa_buffer((XMesaDrawable) p, PIXMAP, v, cmap);
1749   if (!b)
1750      return NULL;
1751
1752#ifdef XFree86Server
1753   client = CLIENT_ID(((XMesaDrawable)p)->id);
1754#endif
1755
1756   if (!initialize_visual_and_buffer(client, v, b, v->mesa_visual.rgbMode,
1757				     (XMesaDrawable) p, cmap)) {
1758      xmesa_free_buffer(b);
1759      return NULL;
1760   }
1761
1762   return b;
1763}
1764
1765
1766
1767XMesaBuffer
1768XMesaCreatePBuffer(XMesaVisual v, XMesaColormap cmap,
1769                   unsigned int width, unsigned int height)
1770{
1771#ifdef XFree86Server
1772   return 0;
1773#else
1774   int client = 0;
1775   XMesaWindow root;
1776   XMesaDrawable drawable;  /* X Pixmap Drawable */
1777   XMesaBuffer b;
1778
1779   /* allocate pixmap for front buffer */
1780   root = RootWindow( v->display, v->visinfo->screen );
1781   drawable = XCreatePixmap(v->display, root, width, height,
1782                            v->visinfo->depth);
1783   if (!drawable)
1784      return NULL;
1785
1786   b = create_xmesa_buffer(drawable, PBUFFER, v, cmap);
1787   if (!b)
1788      return NULL;
1789
1790   if (!initialize_visual_and_buffer(client, v, b, v->mesa_visual.rgbMode,
1791				     drawable, cmap)) {
1792      xmesa_free_buffer(b);
1793      return NULL;
1794   }
1795
1796   return b;
1797#endif
1798}
1799
1800
1801
1802/*
1803 * Deallocate an XMesaBuffer structure and all related info.
1804 */
1805void
1806XMesaDestroyBuffer(XMesaBuffer b)
1807{
1808   xmesa_free_buffer(b);
1809}
1810
1811
1812/**
1813 * Query the current window size and update the corresponding GLframebuffer
1814 * and all attached renderbuffers.
1815 * Called when:
1816 *  1. the first time a buffer is bound to a context.
1817 *  2. from glViewport to poll for window size changes
1818 *  3. from the XMesaResizeBuffers() API function.
1819 * Note: it's possible (and legal) for xmctx to be NULL.  That can happen
1820 * when resizing a buffer when no rendering context is bound.
1821 */
1822void
1823xmesa_check_and_update_buffer_size(XMesaContext xmctx, XMesaBuffer drawBuffer)
1824{
1825   GLuint width, height;
1826   xmesa_get_window_size(drawBuffer->display, drawBuffer, &width, &height);
1827   if (drawBuffer->mesa_buffer.Width != width ||
1828       drawBuffer->mesa_buffer.Height != height) {
1829      GLcontext *ctx = xmctx ? &xmctx->mesa : NULL;
1830      _mesa_resize_framebuffer(ctx, &(drawBuffer->mesa_buffer), width, height);
1831   }
1832   drawBuffer->mesa_buffer.Initialized = GL_TRUE; /* XXX TEMPORARY? */
1833}
1834
1835
1836/*
1837 * Bind buffer b to context c and make c the current rendering context.
1838 */
1839GLboolean XMesaMakeCurrent( XMesaContext c, XMesaBuffer b )
1840{
1841   return XMesaMakeCurrent2( c, b, b );
1842}
1843
1844
1845/*
1846 * Bind buffer b to context c and make c the current rendering context.
1847 */
1848GLboolean XMesaMakeCurrent2( XMesaContext c, XMesaBuffer drawBuffer,
1849                             XMesaBuffer readBuffer )
1850{
1851   if (c) {
1852      if (!drawBuffer || !readBuffer)
1853         return GL_FALSE;  /* must specify buffers! */
1854
1855#ifdef FX
1856      if (drawBuffer->FXctx) {
1857         fxMesaMakeCurrent(drawBuffer->FXctx);
1858
1859         c->xm_buffer = drawBuffer;
1860
1861         return GL_TRUE;
1862      }
1863#endif
1864      if (&(c->mesa) == _mesa_get_current_context()
1865          && c->mesa.DrawBuffer == &drawBuffer->mesa_buffer
1866          && c->mesa.ReadBuffer == &readBuffer->mesa_buffer
1867          && XMESA_BUFFER(c->mesa.DrawBuffer)->wasCurrent) {
1868         /* same context and buffer, do nothing */
1869         return GL_TRUE;
1870      }
1871
1872      c->xm_buffer = drawBuffer;
1873
1874      /* Call this periodically to detect when the user has begun using
1875       * GL rendering from multiple threads.
1876       */
1877      _glapi_check_multithread();
1878
1879      xmesa_check_and_update_buffer_size(c, drawBuffer);
1880      if (readBuffer != drawBuffer)
1881         xmesa_check_and_update_buffer_size(c, readBuffer);
1882
1883      _mesa_make_current(&(c->mesa),
1884                         &drawBuffer->mesa_buffer,
1885                         &readBuffer->mesa_buffer);
1886
1887      if (c->xm_visual->mesa_visual.rgbMode) {
1888         /*
1889          * Must recompute and set these pixel values because colormap
1890          * can be different for different windows.
1891          */
1892         c->clearpixel = xmesa_color_to_pixel( &c->mesa,
1893                                               c->clearcolor[0],
1894                                               c->clearcolor[1],
1895                                               c->clearcolor[2],
1896                                               c->clearcolor[3],
1897                                               c->xm_visual->undithered_pf);
1898         XMesaSetForeground(c->display, drawBuffer->cleargc, c->clearpixel);
1899      }
1900
1901      /* Solution to Stephane Rehel's problem with glXReleaseBuffersMESA(): */
1902      drawBuffer->wasCurrent = GL_TRUE;
1903   }
1904   else {
1905      /* Detach */
1906      _mesa_make_current( NULL, NULL, NULL );
1907   }
1908   return GL_TRUE;
1909}
1910
1911
1912/*
1913 * Unbind the context c from its buffer.
1914 */
1915GLboolean XMesaUnbindContext( XMesaContext c )
1916{
1917   /* A no-op for XFree86 integration purposes */
1918   return GL_TRUE;
1919}
1920
1921
1922XMesaContext XMesaGetCurrentContext( void )
1923{
1924   GET_CURRENT_CONTEXT(ctx);
1925   if (ctx) {
1926      XMesaContext xmesa = XMESA_CONTEXT(ctx);
1927      return xmesa;
1928   }
1929   else {
1930      return 0;
1931   }
1932}
1933
1934
1935XMesaBuffer XMesaGetCurrentBuffer( void )
1936{
1937   GET_CURRENT_CONTEXT(ctx);
1938   if (ctx) {
1939      XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
1940      return xmbuf;
1941   }
1942   else {
1943      return 0;
1944   }
1945}
1946
1947
1948/* New in Mesa 3.1 */
1949XMesaBuffer XMesaGetCurrentReadBuffer( void )
1950{
1951   GET_CURRENT_CONTEXT(ctx);
1952   if (ctx) {
1953      return XMESA_BUFFER(ctx->ReadBuffer);
1954   }
1955   else {
1956      return 0;
1957   }
1958}
1959
1960
1961GLboolean XMesaForceCurrent(XMesaContext c)
1962{
1963   if (c) {
1964#ifdef XGLServer
1965      _glapi_set_dispatch(c->mesa.CurrentDispatch);
1966#endif
1967
1968      if (&(c->mesa) != _mesa_get_current_context()) {
1969	 _mesa_make_current(&c->mesa, c->mesa.DrawBuffer, c->mesa.ReadBuffer);
1970      }
1971   }
1972   else {
1973      _mesa_make_current(NULL, NULL, NULL);
1974   }
1975   return GL_TRUE;
1976}
1977
1978
1979GLboolean XMesaLoseCurrent(XMesaContext c)
1980{
1981   (void) c;
1982   _mesa_make_current(NULL, NULL, NULL);
1983   return GL_TRUE;
1984}
1985
1986
1987GLboolean XMesaCopyContext( XMesaContext xm_src, XMesaContext xm_dst, GLuint mask )
1988{
1989   _mesa_copy_context(&xm_src->mesa, &xm_dst->mesa, mask);
1990   return GL_TRUE;
1991}
1992
1993
1994/*
1995 * Switch 3Dfx support hack between window and full-screen mode.
1996 */
1997GLboolean XMesaSetFXmode( GLint mode )
1998{
1999#ifdef FX
2000   const char *fx = _mesa_getenv("MESA_GLX_FX");
2001   if (fx && fx[0] != 'd') {
2002      GET_CURRENT_CONTEXT(ctx);
2003      GrHwConfiguration hw;
2004      if (!FX_grSstQueryHardware(&hw)) {
2005         /*fprintf(stderr, "!grSstQueryHardware\n");*/
2006         return GL_FALSE;
2007      }
2008      if (hw.num_sst < 1) {
2009         /*fprintf(stderr, "hw.num_sst < 1\n");*/
2010         return GL_FALSE;
2011      }
2012      if (ctx) {
2013         /* [dBorca] Hack alert:
2014	  * oh, this is sooo wrong: ctx above is
2015	  * really an fxMesaContext, not an XMesaContext
2016	  */
2017         XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
2018         if (mode == XMESA_FX_WINDOW) {
2019	    if (xmbuf->FXisHackUsable) {
2020	       FX_grSstControl(GR_CONTROL_DEACTIVATE);
2021	       xmbuf->FXwindowHack = GL_TRUE;
2022	       return GL_TRUE;
2023	    }
2024	 }
2025	 else if (mode == XMESA_FX_FULLSCREEN) {
2026	    FX_grSstControl(GR_CONTROL_ACTIVATE);
2027	    xmbuf->FXwindowHack = GL_FALSE;
2028	    return GL_TRUE;
2029	 }
2030	 else {
2031	    /* Error: Bad mode value */
2032	 }
2033      }
2034   }
2035   /*fprintf(stderr, "fallthrough\n");*/
2036#else
2037   (void) mode;
2038#endif
2039   return GL_FALSE;
2040}
2041
2042
2043
2044#ifdef FX
2045/*
2046 * Read image from VooDoo frame buffer into X/Mesa's back XImage.
2047 */
2048static void FXgetImage( XMesaBuffer b )
2049{
2050   GET_CURRENT_CONTEXT(ctx);
2051   static unsigned short pixbuf[MAX_WIDTH];
2052   GLuint x, y;
2053   GLuint width, height;
2054   XMesaContext xmesa = XMESA_CONTEXT(ctx);
2055
2056#ifdef XFree86Server
2057   x = b->frontxrb->pixmap->x;
2058   y = b->frontxrb->pixmap->y;
2059   width = b->frontxrb->pixmap->width;
2060   height = b->frontxrb->pixmap->height;
2061   depth = b->frontxrb->pixmap->depth;
2062#else
2063   xmesa_get_window_size(b->display, b, &width, &height);
2064   x = y = 0;
2065#endif
2066   if (b->mesa_buffer.Width != width || b->mesa_buffer.Height != height) {
2067      b->mesa_buffer.Width = MIN2((int)width, b->FXctx->width);
2068      b->mesa_buffer.Height = MIN2((int)height, b->FXctx->height);
2069      if (b->mesa_buffer.Width & 1)
2070         b->mesa_buffer.Width--;  /* prevent odd width */
2071   }
2072
2073   /* [dBorca] we're always in the right GR_COLORFORMAT... aren't we? */
2074   /* grLfbWriteColorFormat(GR_COLORFORMAT_ARGB); */
2075   if (b->xm_visual->undithered_pf==PF_5R6G5B) {
2076      /* Special case: 16bpp RGB */
2077      grLfbReadRegion( GR_BUFFER_FRONTBUFFER,       /* src buffer */
2078                       0, b->FXctx->height - b->mesa_buffer.Height,  /*pos*/
2079                       b->mesa_buffer.Width, b->mesa_buffer.Height,  /* size */
2080                       b->mesa_buffer.Width * sizeof(GLushort), /* stride */
2081                       b->backxrb->ximage->data);         /* dest buffer */
2082   }
2083   else if (b->xm_visual->dithered_pf==PF_Dither
2084	    && GET_VISUAL_DEPTH(b->xm_visual)==8) {
2085      /* Special case: 8bpp RGB */
2086      for (y=0;y<b->mesa_buffer.Height;y++) {
2087         GLubyte *ptr = (GLubyte*) b->backxrb->ximage->data
2088                        + b->backxrb->ximage->bytes_per_line * y;
2089         XDITHER_SETUP(y);
2090
2091         /* read row from 3Dfx frame buffer */
2092         grLfbReadRegion( GR_BUFFER_FRONTBUFFER,
2093                          0, b->FXctx->height-(b->mesa_buffer.Height-y),
2094                          b->mesa_buffer.Width, 1,
2095                          0,
2096                          pixbuf );
2097
2098         /* write to XImage back buffer */
2099         for (x=0;x<b->mesa_buffer.Width;x++) {
2100            GLubyte r = (pixbuf[x] & 0xf800) >> 8;
2101            GLubyte g = (pixbuf[x] & 0x07e0) >> 3;
2102            GLubyte b = (pixbuf[x] & 0x001f) << 3;
2103            *ptr++ = XDITHER( x, r, g, b);
2104         }
2105      }
2106   }
2107   else {
2108      /* General case: slow! */
2109      for (y=0;y<b->mesa_buffer.Height;y++) {
2110         /* read row from 3Dfx frame buffer */
2111         grLfbReadRegion( GR_BUFFER_FRONTBUFFER,
2112                          0, b->FXctx->height-(b->mesa_buffer.Height-y),
2113                          b->mesa_buffer.Width, 1,
2114                          0,
2115                          pixbuf );
2116
2117         /* write to XImage back buffer */
2118         for (x=0;x<b->mesa_buffer.Width;x++) {
2119            XMesaPutPixel(b->backxrb->ximage,x,y,
2120			  xmesa_color_to_pixel(ctx,
2121					       (pixbuf[x] & 0xf800) >> 8,
2122					       (pixbuf[x] & 0x07e0) >> 3,
2123					       (pixbuf[x] & 0x001f) << 3,
2124					       0xff,
2125                                               b->xm_visual->undithered_pf));
2126         }
2127      }
2128   }
2129   /* grLfbWriteColorFormat(GR_COLORFORMAT_ABGR); */
2130}
2131#endif
2132
2133
2134/*
2135 * Copy the back buffer to the front buffer.  If there's no back buffer
2136 * this is a no-op.
2137 */
2138void XMesaSwapBuffers( XMesaBuffer b )
2139{
2140   GET_CURRENT_CONTEXT(ctx);
2141
2142   if (!b->backxrb) {
2143      /* single buffered */
2144      return;
2145   }
2146
2147   /* If we're swapping the buffer associated with the current context
2148    * we have to flush any pending rendering commands first.
2149    */
2150   if (ctx && ctx->DrawBuffer == &(b->mesa_buffer))
2151      _mesa_notifySwapBuffers(ctx);
2152
2153   if (b->db_mode) {
2154#ifdef FX
2155      if (b->FXctx) {
2156         fxMesaSwapBuffers();
2157
2158         if (b->FXwindowHack)
2159            FXgetImage(b);
2160         else
2161            return;
2162      }
2163#endif
2164     if (b->backxrb->ximage) {
2165	 /* Copy Ximage (back buf) from client memory to server window */
2166#if defined(USE_XSHM) && !defined(XFree86Server)
2167	 if (b->shm) {
2168            /*_glthread_LOCK_MUTEX(_xmesa_lock);*/
2169	    XShmPutImage( b->xm_visual->display, b->frontxrb->drawable,
2170			  b->swapgc,
2171			  b->backxrb->ximage, 0, 0,
2172			  0, 0, b->mesa_buffer.Width, b->mesa_buffer.Height,
2173                          False );
2174            /*_glthread_UNLOCK_MUTEX(_xmesa_lock);*/
2175	 }
2176	 else
2177#endif
2178         {
2179            /*_glthread_LOCK_MUTEX(_xmesa_lock);*/
2180            XMesaPutImage( b->xm_visual->display, b->frontxrb->drawable,
2181			   b->swapgc,
2182			   b->backxrb->ximage, 0, 0,
2183			   0, 0, b->mesa_buffer.Width, b->mesa_buffer.Height );
2184            /*_glthread_UNLOCK_MUTEX(_xmesa_lock);*/
2185         }
2186      }
2187      else if (b->backxrb->pixmap) {
2188	 /* Copy pixmap (back buf) to window (front buf) on server */
2189         /*_glthread_LOCK_MUTEX(_xmesa_lock);*/
2190	 XMesaCopyArea( b->xm_visual->display,
2191			b->backxrb->pixmap,   /* source drawable */
2192			b->frontxrb->drawable,  /* dest. drawable */
2193			b->swapgc,
2194			0, 0, b->mesa_buffer.Width, b->mesa_buffer.Height,
2195			0, 0                 /* dest region */
2196		      );
2197         /*_glthread_UNLOCK_MUTEX(_xmesa_lock);*/
2198      }
2199
2200      if (b->swAlpha)
2201         _mesa_copy_soft_alpha_renderbuffers(ctx, &b->mesa_buffer);
2202   }
2203#if !defined(XFree86Server)
2204   XSync( b->xm_visual->display, False );
2205#endif
2206}
2207
2208
2209
2210/*
2211 * Copy sub-region of back buffer to front buffer
2212 */
2213void XMesaCopySubBuffer( XMesaBuffer b, int x, int y, int width, int height )
2214{
2215   GET_CURRENT_CONTEXT(ctx);
2216
2217   /* If we're swapping the buffer associated with the current context
2218    * we have to flush any pending rendering commands first.
2219    */
2220   if (ctx && ctx->DrawBuffer == &(b->mesa_buffer))
2221      _mesa_notifySwapBuffers(ctx);
2222
2223   if (!b->backxrb) {
2224      /* single buffered */
2225      return;
2226   }
2227
2228   if (b->db_mode) {
2229      int yTop = b->mesa_buffer.Height - y - height;
2230#ifdef FX
2231      if (b->FXctx) {
2232         fxMesaSwapBuffers();
2233         if (b->FXwindowHack)
2234            FXgetImage(b);
2235         else
2236            return;
2237      }
2238#endif
2239      if (b->backxrb->ximage) {
2240         /* Copy Ximage from host's memory to server's window */
2241#if defined(USE_XSHM) && !defined(XFree86Server)
2242         if (b->shm) {
2243            /* XXX assuming width and height aren't too large! */
2244            XShmPutImage( b->xm_visual->display, b->frontxrb->drawable,
2245                          b->swapgc,
2246                          b->backxrb->ximage, x, yTop,
2247                          x, yTop, width, height, False );
2248            /* wait for finished event??? */
2249         }
2250         else
2251#endif
2252         {
2253            /* XXX assuming width and height aren't too large! */
2254            XMesaPutImage( b->xm_visual->display, b->frontxrb->drawable,
2255			   b->swapgc,
2256			   b->backxrb->ximage, x, yTop,
2257			   x, yTop, width, height );
2258         }
2259      }
2260      else {
2261         /* Copy pixmap to window on server */
2262         XMesaCopyArea( b->xm_visual->display,
2263			b->backxrb->pixmap,           /* source drawable */
2264			b->frontxrb->drawable,        /* dest. drawable */
2265			b->swapgc,
2266			x, yTop, width, height,  /* source region */
2267			x, yTop                  /* dest region */
2268                      );
2269      }
2270   }
2271}
2272
2273
2274/*
2275 * Return a pointer to the XMesa backbuffer Pixmap or XImage.  This function
2276 * is a way to get "under the hood" of X/Mesa so one can manipulate the
2277 * back buffer directly.
2278 * Output:  pixmap - pointer to back buffer's Pixmap, or 0
2279 *          ximage - pointer to back buffer's XImage, or NULL
2280 * Return:  GL_TRUE = context is double buffered
2281 *          GL_FALSE = context is single buffered
2282 */
2283#ifndef XFree86Server
2284GLboolean XMesaGetBackBuffer( XMesaBuffer b,
2285                              XMesaPixmap *pixmap,
2286                              XMesaImage **ximage )
2287{
2288   if (b->db_mode) {
2289      if (pixmap)
2290         *pixmap = b->backxrb->pixmap;
2291      if (ximage)
2292         *ximage = b->backxrb->ximage;
2293      return GL_TRUE;
2294   }
2295   else {
2296      *pixmap = 0;
2297      *ximage = NULL;
2298      return GL_FALSE;
2299   }
2300}
2301#endif /* XFree86Server */
2302
2303
2304/*
2305 * Return the depth buffer associated with an XMesaBuffer.
2306 * Input:  b - the XMesa buffer handle
2307 * Output:  width, height - size of buffer in pixels
2308 *          bytesPerValue - bytes per depth value (2 or 4)
2309 *          buffer - pointer to depth buffer values
2310 * Return:  GL_TRUE or GL_FALSE to indicate success or failure.
2311 */
2312GLboolean XMesaGetDepthBuffer( XMesaBuffer b, GLint *width, GLint *height,
2313                               GLint *bytesPerValue, void **buffer )
2314{
2315   struct gl_renderbuffer *rb
2316      = b->mesa_buffer.Attachment[BUFFER_DEPTH].Renderbuffer;
2317   if (!rb || !rb->Data) {
2318      *width = 0;
2319      *height = 0;
2320      *bytesPerValue = 0;
2321      *buffer = 0;
2322      return GL_FALSE;
2323   }
2324   else {
2325      *width = b->mesa_buffer.Width;
2326      *height = b->mesa_buffer.Height;
2327      *bytesPerValue = b->mesa_buffer.Visual.depthBits <= 16
2328         ? sizeof(GLushort) : sizeof(GLuint);
2329      *buffer = rb->Data;
2330      return GL_TRUE;
2331   }
2332}
2333
2334
2335void XMesaFlush( XMesaContext c )
2336{
2337   if (c && c->xm_visual) {
2338#ifdef XFree86Server
2339      /* NOT_NEEDED */
2340#else
2341      XSync( c->xm_visual->display, False );
2342#endif
2343   }
2344}
2345
2346
2347
2348const char *XMesaGetString( XMesaContext c, int name )
2349{
2350   (void) c;
2351   if (name==XMESA_VERSION) {
2352      return "5.0";
2353   }
2354   else if (name==XMESA_EXTENSIONS) {
2355      return "";
2356   }
2357   else {
2358      return NULL;
2359   }
2360}
2361
2362
2363
2364XMesaBuffer XMesaFindBuffer( XMesaDisplay *dpy, XMesaDrawable d )
2365{
2366   XMesaBuffer b;
2367   for (b=XMesaBufferList; b; b=b->Next) {
2368      if (b->frontxrb->drawable == d && b->display == dpy) {
2369         return b;
2370      }
2371   }
2372   return NULL;
2373}
2374
2375
2376/**
2377 * Free/destroy all XMesaBuffers associated with given display.
2378 */
2379void xmesa_destroy_buffers_on_display(XMesaDisplay *dpy)
2380{
2381   XMesaBuffer b, next;
2382   for (b = XMesaBufferList; b; b = next) {
2383      next = b->Next;
2384      if (b->display == dpy) {
2385         xmesa_free_buffer(b);
2386      }
2387   }
2388}
2389
2390
2391/*
2392 * Look for XMesaBuffers whose X window has been destroyed.
2393 * Deallocate any such XMesaBuffers.
2394 */
2395void XMesaGarbageCollect( void )
2396{
2397   XMesaBuffer b, next;
2398   for (b=XMesaBufferList; b; b=next) {
2399      next = b->Next;
2400      if (b->display && b->frontxrb->drawable && b->type == WINDOW) {
2401#ifdef XFree86Server
2402	 /* NOT_NEEDED */
2403#else
2404         XSync(b->display, False);
2405         if (!window_exists( b->display, b->frontxrb->drawable )) {
2406            /* found a dead window, free the ancillary info */
2407            XMesaDestroyBuffer( b );
2408         }
2409#endif
2410      }
2411   }
2412}
2413
2414
2415unsigned long XMesaDitherColor( XMesaContext xmesa, GLint x, GLint y,
2416                                GLfloat red, GLfloat green,
2417                                GLfloat blue, GLfloat alpha )
2418{
2419   GLcontext *ctx = &xmesa->mesa;
2420   GLint r = (GLint) (red   * 255.0F);
2421   GLint g = (GLint) (green * 255.0F);
2422   GLint b = (GLint) (blue  * 255.0F);
2423   GLint a = (GLint) (alpha * 255.0F);
2424
2425   switch (xmesa->pixelformat) {
2426      case PF_Index:
2427         return 0;
2428      case PF_Truecolor:
2429         {
2430            unsigned long p;
2431            PACK_TRUECOLOR( p, r, g, b );
2432            return p;
2433         }
2434      case PF_8A8B8G8R:
2435         return PACK_8A8B8G8R( r, g, b, a );
2436      case PF_8A8R8G8B:
2437         return PACK_8A8R8G8B( r, g, b, a );
2438      case PF_8R8G8B:
2439         return PACK_8R8G8B( r, g, b );
2440      case PF_5R6G5B:
2441         return PACK_5R6G5B( r, g, b );
2442      case PF_Dither:
2443         {
2444            DITHER_SETUP;
2445            return DITHER( x, y, r, g, b );
2446         }
2447      case PF_1Bit:
2448         /* 382 = (3*255)/2 */
2449         return ((r+g+b) > 382) ^ xmesa->xm_visual->bitFlip;
2450      case PF_HPCR:
2451         return DITHER_HPCR(x, y, r, g, b);
2452      case PF_Lookup:
2453         {
2454            LOOKUP_SETUP;
2455            return LOOKUP( r, g, b );
2456         }
2457      case PF_Grayscale:
2458         return GRAY_RGB( r, g, b );
2459      case PF_Dither_5R6G5B:
2460         /* fall through */
2461      case PF_Dither_True:
2462         {
2463            unsigned long p;
2464            PACK_TRUEDITHER(p, x, y, r, g, b);
2465            return p;
2466         }
2467      default:
2468         _mesa_problem(NULL, "Bad pixel format in XMesaDitherColor");
2469   }
2470   return 0;
2471}
2472
2473
2474/*
2475 * This is typically called when the window size changes and we need
2476 * to reallocate the buffer's back/depth/stencil/accum buffers.
2477 */
2478void
2479XMesaResizeBuffers( XMesaBuffer b )
2480{
2481   GET_CURRENT_CONTEXT(ctx);
2482   XMesaContext xmctx = XMESA_CONTEXT(ctx);
2483   if (!xmctx)
2484      return;
2485   xmesa_check_and_update_buffer_size(xmctx, b);
2486}
2487
2488