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      1 /*
      2  * Mesa 3-D graphics library
      3  * Version:  7.1
      4  *
      5  * Copyright (C) 1999-2007  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 "xmesaP.h"
     67 #include "main/context.h"
     68 #include "main/extensions.h"
     69 #include "main/framebuffer.h"
     70 #include "main/imports.h"
     71 #include "main/macros.h"
     72 #include "main/renderbuffer.h"
     73 #include "main/teximage.h"
     74 #include "glapi/glthread.h"
     75 #include "swrast/swrast.h"
     76 #include "swrast/s_renderbuffer.h"
     77 #include "swrast_setup/swrast_setup.h"
     78 #include "vbo/vbo.h"
     79 #include "tnl/tnl.h"
     80 #include "tnl/t_context.h"
     81 #include "tnl/t_pipeline.h"
     82 #include "drivers/common/driverfuncs.h"
     83 #include "drivers/common/meta.h"
     84 
     85 /**
     86  * Global X driver lock
     87  */
     88 _glthread_Mutex _xmesa_lock;
     89 
     90 
     91 
     92 /**********************************************************************/
     93 /*****                     X Utility Functions                    *****/
     94 /**********************************************************************/
     95 
     96 
     97 /**
     98  * Return the host's byte order as LSBFirst or MSBFirst ala X.
     99  */
    100 static int host_byte_order( void )
    101 {
    102    int i = 1;
    103    char *cptr = (char *) &i;
    104    return (*cptr==1) ? LSBFirst : MSBFirst;
    105 }
    106 
    107 
    108 /**
    109  * Check if the X Shared Memory extension is available.
    110  * Return:  0 = not available
    111  *          1 = shared XImage support available
    112  *          2 = shared Pixmap support available also
    113  */
    114 static int check_for_xshm( XMesaDisplay *display )
    115 {
    116 #if defined(USE_XSHM)
    117    int ignore;
    118 
    119    if (XQueryExtension( display, "MIT-SHM", &ignore, &ignore, &ignore )) {
    120       /* Note: we're no longer calling XShmQueryVersion() here.  It seems
    121        * to be flakey (triggers a spurious X protocol error when we close
    122        * one display connection and start using a new one.  XShm has been
    123        * around a long time and hasn't changed so if MIT_SHM is supported
    124        * we assume we're good to go.
    125        */
    126       return 2;
    127    }
    128    else {
    129       return 0;
    130    }
    131 #else
    132    /* No  XSHM support */
    133    return 0;
    134 #endif
    135 }
    136 
    137 
    138 /**
    139  * Apply gamma correction to an intensity value in [0..max].  Return the
    140  * new intensity value.
    141  */
    142 static GLint
    143 gamma_adjust( GLfloat gamma, GLint value, GLint max )
    144 {
    145    if (gamma == 1.0) {
    146       return value;
    147    }
    148    else {
    149       double x = (double) value / (double) max;
    150       return IROUND_POS((GLfloat) max * pow(x, 1.0F/gamma));
    151    }
    152 }
    153 
    154 
    155 
    156 /**
    157  * Return the true number of bits per pixel for XImages.
    158  * For example, if we request a 24-bit deep visual we may actually need/get
    159  * 32bpp XImages.  This function returns the appropriate bpp.
    160  * Input:  dpy - the X display
    161  *         visinfo - desribes the visual to be used for XImages
    162  * Return:  true number of bits per pixel for XImages
    163  */
    164 static int
    165 bits_per_pixel( XMesaVisual xmv )
    166 {
    167    XMesaDisplay *dpy = xmv->display;
    168    XMesaVisualInfo visinfo = xmv->visinfo;
    169    XMesaImage *img;
    170    int bitsPerPixel;
    171    /* Create a temporary XImage */
    172    img = XCreateImage( dpy, visinfo->visual, visinfo->depth,
    173 		       ZPixmap, 0,           /*format, offset*/
    174 		       (char*) MALLOC(8),    /*data*/
    175 		       1, 1,                 /*width, height*/
    176 		       32,                   /*bitmap_pad*/
    177 		       0                     /*bytes_per_line*/
    178                      );
    179    assert(img);
    180    /* grab the bits/pixel value */
    181    bitsPerPixel = img->bits_per_pixel;
    182    /* free the XImage */
    183    free( img->data );
    184    img->data = NULL;
    185    XMesaDestroyImage( img );
    186    return bitsPerPixel;
    187 }
    188 
    189 
    190 
    191 /*
    192  * Determine if a given X window ID is valid (window exists).
    193  * Do this by calling XGetWindowAttributes() for the window and
    194  * checking if we catch an X error.
    195  * Input:  dpy - the display
    196  *         win - the window to check for existance
    197  * Return:  GL_TRUE - window exists
    198  *          GL_FALSE - window doesn't exist
    199  */
    200 static GLboolean WindowExistsFlag;
    201 
    202 static int window_exists_err_handler( XMesaDisplay* dpy, XErrorEvent* xerr )
    203 {
    204    (void) dpy;
    205    if (xerr->error_code == BadWindow) {
    206       WindowExistsFlag = GL_FALSE;
    207    }
    208    return 0;
    209 }
    210 
    211 static GLboolean window_exists( XMesaDisplay *dpy, Window win )
    212 {
    213    XWindowAttributes wa;
    214    int (*old_handler)( XMesaDisplay*, XErrorEvent* );
    215    WindowExistsFlag = GL_TRUE;
    216    old_handler = XSetErrorHandler(window_exists_err_handler);
    217    XGetWindowAttributes( dpy, win, &wa ); /* dummy request */
    218    XSetErrorHandler(old_handler);
    219    return WindowExistsFlag;
    220 }
    221 
    222 static Status
    223 get_drawable_size( XMesaDisplay *dpy, Drawable d, GLuint *width, GLuint *height )
    224 {
    225    Window root;
    226    Status stat;
    227    int xpos, ypos;
    228    unsigned int w, h, bw, depth;
    229    stat = XGetGeometry(dpy, d, &root, &xpos, &ypos, &w, &h, &bw, &depth);
    230    *width = w;
    231    *height = h;
    232    return stat;
    233 }
    234 
    235 
    236 /**
    237  * Return the size of the window (or pixmap) that corresponds to the
    238  * given XMesaBuffer.
    239  * \param width  returns width in pixels
    240  * \param height  returns height in pixels
    241  */
    242 void
    243 xmesa_get_window_size(XMesaDisplay *dpy, XMesaBuffer b,
    244                       GLuint *width, GLuint *height)
    245 {
    246    Status stat;
    247 
    248    _glthread_LOCK_MUTEX(_xmesa_lock);
    249    XSync(b->xm_visual->display, 0); /* added for Chromium */
    250    stat = get_drawable_size(dpy, b->frontxrb->pixmap, width, height);
    251    _glthread_UNLOCK_MUTEX(_xmesa_lock);
    252 
    253    if (!stat) {
    254       /* probably querying a window that's recently been destroyed */
    255       _mesa_warning(NULL, "XGetGeometry failed!\n");
    256       *width = *height = 1;
    257    }
    258 }
    259 
    260 
    261 
    262 /**********************************************************************/
    263 /*****                Linked list of XMesaBuffers                 *****/
    264 /**********************************************************************/
    265 
    266 XMesaBuffer XMesaBufferList = NULL;
    267 
    268 
    269 /**
    270  * Allocate a new XMesaBuffer object which corresponds to the given drawable.
    271  * Note that XMesaBuffer is derived from struct gl_framebuffer.
    272  * The new XMesaBuffer will not have any size (Width=Height=0).
    273  *
    274  * \param d  the corresponding X drawable (window or pixmap)
    275  * \param type  either WINDOW, PIXMAP or PBUFFER, describing d
    276  * \param vis  the buffer's visual
    277  * \param cmap  the window's colormap, if known.
    278  * \return new XMesaBuffer or NULL if any problem
    279  */
    280 static XMesaBuffer
    281 create_xmesa_buffer(XMesaDrawable d, BufferType type,
    282                     XMesaVisual vis, XMesaColormap cmap)
    283 {
    284    XMesaBuffer b;
    285 
    286    ASSERT(type == WINDOW || type == PIXMAP || type == PBUFFER);
    287 
    288    b = (XMesaBuffer) CALLOC_STRUCT(xmesa_buffer);
    289    if (!b)
    290       return NULL;
    291 
    292    b->display = vis->display;
    293    b->xm_visual = vis;
    294    b->type = type;
    295    b->cmap = cmap;
    296 
    297    _mesa_initialize_window_framebuffer(&b->mesa_buffer, &vis->mesa_visual);
    298    b->mesa_buffer.Delete = xmesa_delete_framebuffer;
    299 
    300    /*
    301     * Front renderbuffer
    302     */
    303    b->frontxrb = xmesa_new_renderbuffer(NULL, 0, vis, GL_FALSE);
    304    if (!b->frontxrb) {
    305       free(b);
    306       return NULL;
    307    }
    308    b->frontxrb->Parent = b;
    309    b->frontxrb->drawable = d;
    310    b->frontxrb->pixmap = (XMesaPixmap) d;
    311    _mesa_add_renderbuffer(&b->mesa_buffer, BUFFER_FRONT_LEFT,
    312                           &b->frontxrb->Base.Base);
    313 
    314    /*
    315     * Back renderbuffer
    316     */
    317    if (vis->mesa_visual.doubleBufferMode) {
    318       b->backxrb = xmesa_new_renderbuffer(NULL, 0, vis, GL_TRUE);
    319       if (!b->backxrb) {
    320          /* XXX free front xrb too */
    321          free(b);
    322          return NULL;
    323       }
    324       b->backxrb->Parent = b;
    325       /* determine back buffer implementation */
    326       b->db_mode = vis->ximage_flag ? BACK_XIMAGE : BACK_PIXMAP;
    327 
    328       _mesa_add_renderbuffer(&b->mesa_buffer, BUFFER_BACK_LEFT,
    329                              &b->backxrb->Base.Base);
    330    }
    331 
    332    /*
    333     * Other renderbuffer (depth, stencil, etc)
    334     */
    335    _swrast_add_soft_renderbuffers(&b->mesa_buffer,
    336                                   GL_FALSE,  /* color */
    337                                   vis->mesa_visual.haveDepthBuffer,
    338                                   vis->mesa_visual.haveStencilBuffer,
    339                                   vis->mesa_visual.haveAccumBuffer,
    340                                   GL_FALSE,  /* software alpha buffer */
    341                                   vis->mesa_visual.numAuxBuffers > 0 );
    342 
    343    /* GLX_EXT_texture_from_pixmap */
    344    b->TextureTarget = 0;
    345    b->TextureFormat = GLX_TEXTURE_FORMAT_NONE_EXT;
    346    b->TextureMipmap = 0;
    347 
    348    /* insert buffer into linked list */
    349    b->Next = XMesaBufferList;
    350    XMesaBufferList = b;
    351 
    352    return b;
    353 }
    354 
    355 
    356 /**
    357  * Find an XMesaBuffer by matching X display and colormap but NOT matching
    358  * the notThis buffer.
    359  */
    360 XMesaBuffer
    361 xmesa_find_buffer(XMesaDisplay *dpy, XMesaColormap cmap, XMesaBuffer notThis)
    362 {
    363    XMesaBuffer b;
    364    for (b=XMesaBufferList; b; b=b->Next) {
    365       if (b->display==dpy && b->cmap==cmap && b!=notThis) {
    366          return b;
    367       }
    368    }
    369    return NULL;
    370 }
    371 
    372 
    373 /**
    374  * Remove buffer from linked list, delete if no longer referenced.
    375  */
    376 static void
    377 xmesa_free_buffer(XMesaBuffer buffer)
    378 {
    379    XMesaBuffer prev = NULL, b;
    380 
    381    for (b = XMesaBufferList; b; b = b->Next) {
    382       if (b == buffer) {
    383          struct gl_framebuffer *fb = &buffer->mesa_buffer;
    384 
    385          /* unlink buffer from list */
    386          if (prev)
    387             prev->Next = buffer->Next;
    388          else
    389             XMesaBufferList = buffer->Next;
    390 
    391          /* mark as delete pending */
    392          fb->DeletePending = GL_TRUE;
    393 
    394          /* Since the X window for the XMesaBuffer is going away, we don't
    395           * want to dereference this pointer in the future.
    396           */
    397          b->frontxrb->drawable = 0;
    398 
    399          /* Unreference.  If count = zero we'll really delete the buffer */
    400          _mesa_reference_framebuffer(&fb, NULL);
    401 
    402          return;
    403       }
    404       /* continue search */
    405       prev = b;
    406    }
    407    /* buffer not found in XMesaBufferList */
    408    _mesa_problem(NULL,"xmesa_free_buffer() - buffer not found\n");
    409 }
    410 
    411 
    412 
    413 
    414 /**********************************************************************/
    415 /*****                   Misc Private Functions                   *****/
    416 /**********************************************************************/
    417 
    418 
    419 /**
    420  * Setup RGB rendering for a window with a True/DirectColor visual.
    421  */
    422 static void
    423 setup_truecolor(XMesaVisual v, XMesaBuffer buffer, XMesaColormap cmap)
    424 {
    425    unsigned long rmask, gmask, bmask;
    426    (void) buffer;
    427    (void) cmap;
    428 
    429    /* Compute red multiplier (mask) and bit shift */
    430    v->rshift = 0;
    431    rmask = GET_REDMASK(v);
    432    while ((rmask & 1)==0) {
    433       v->rshift++;
    434       rmask = rmask >> 1;
    435    }
    436 
    437    /* Compute green multiplier (mask) and bit shift */
    438    v->gshift = 0;
    439    gmask = GET_GREENMASK(v);
    440    while ((gmask & 1)==0) {
    441       v->gshift++;
    442       gmask = gmask >> 1;
    443    }
    444 
    445    /* Compute blue multiplier (mask) and bit shift */
    446    v->bshift = 0;
    447    bmask = GET_BLUEMASK(v);
    448    while ((bmask & 1)==0) {
    449       v->bshift++;
    450       bmask = bmask >> 1;
    451    }
    452 
    453    /*
    454     * Compute component-to-pixel lookup tables and dithering kernel
    455     */
    456    {
    457       static GLubyte kernel[16] = {
    458           0*16,  8*16,  2*16, 10*16,
    459          12*16,  4*16, 14*16,  6*16,
    460           3*16, 11*16,  1*16,  9*16,
    461          15*16,  7*16, 13*16,  5*16,
    462       };
    463       GLint rBits = _mesa_bitcount(rmask);
    464       GLint gBits = _mesa_bitcount(gmask);
    465       GLint bBits = _mesa_bitcount(bmask);
    466       GLint maxBits;
    467       GLuint i;
    468 
    469       /* convert pixel components in [0,_mask] to RGB values in [0,255] */
    470       for (i=0; i<=rmask; i++)
    471          v->PixelToR[i] = (unsigned char) ((i * 255) / rmask);
    472       for (i=0; i<=gmask; i++)
    473          v->PixelToG[i] = (unsigned char) ((i * 255) / gmask);
    474       for (i=0; i<=bmask; i++)
    475          v->PixelToB[i] = (unsigned char) ((i * 255) / bmask);
    476 
    477       /* convert RGB values from [0,255] to pixel components */
    478 
    479       for (i=0;i<256;i++) {
    480          GLint r = gamma_adjust(v->RedGamma,   i, 255);
    481          GLint g = gamma_adjust(v->GreenGamma, i, 255);
    482          GLint b = gamma_adjust(v->BlueGamma,  i, 255);
    483          v->RtoPixel[i] = (r >> (8-rBits)) << v->rshift;
    484          v->GtoPixel[i] = (g >> (8-gBits)) << v->gshift;
    485          v->BtoPixel[i] = (b >> (8-bBits)) << v->bshift;
    486       }
    487       /* overflow protection */
    488       for (i=256;i<512;i++) {
    489          v->RtoPixel[i] = v->RtoPixel[255];
    490          v->GtoPixel[i] = v->GtoPixel[255];
    491          v->BtoPixel[i] = v->BtoPixel[255];
    492       }
    493 
    494       /* setup dithering kernel */
    495       maxBits = rBits;
    496       if (gBits > maxBits)  maxBits = gBits;
    497       if (bBits > maxBits)  maxBits = bBits;
    498       for (i=0;i<16;i++) {
    499          v->Kernel[i] = kernel[i] >> maxBits;
    500       }
    501 
    502       v->undithered_pf = PF_Truecolor;
    503       v->dithered_pf = (GET_VISUAL_DEPTH(v)<24) ? PF_Dither_True : PF_Truecolor;
    504    }
    505 
    506    /*
    507     * Now check for TrueColor visuals which we can optimize.
    508     */
    509    if (   GET_REDMASK(v)  ==0x0000ff
    510        && GET_GREENMASK(v)==0x00ff00
    511        && GET_BLUEMASK(v) ==0xff0000
    512        && CHECK_BYTE_ORDER(v)
    513        && v->BitsPerPixel==32
    514        && v->RedGamma==1.0 && v->GreenGamma==1.0 && v->BlueGamma==1.0) {
    515       /* common 32 bpp config used on SGI, Sun */
    516       v->undithered_pf = v->dithered_pf = PF_8A8B8G8R; /* ABGR */
    517    }
    518    else if (GET_REDMASK(v)  == 0xff0000
    519          && GET_GREENMASK(v)== 0x00ff00
    520          && GET_BLUEMASK(v) == 0x0000ff
    521          && CHECK_BYTE_ORDER(v)
    522          && v->RedGamma == 1.0 && v->GreenGamma == 1.0 && v->BlueGamma == 1.0){
    523       if (v->BitsPerPixel==32) {
    524          /* if 32 bpp, and visual indicates 8 bpp alpha channel */
    525          if (GET_VISUAL_DEPTH(v) == 32 && v->mesa_visual.alphaBits == 8)
    526             v->undithered_pf = v->dithered_pf = PF_8A8R8G8B; /* ARGB */
    527          else
    528             v->undithered_pf = v->dithered_pf = PF_8R8G8B; /* xRGB */
    529       }
    530       else if (v->BitsPerPixel == 24) {
    531          v->undithered_pf = v->dithered_pf = PF_8R8G8B24; /* RGB */
    532       }
    533    }
    534    else if (GET_REDMASK(v)  ==0xf800
    535        &&   GET_GREENMASK(v)==0x07e0
    536        &&   GET_BLUEMASK(v) ==0x001f
    537        && CHECK_BYTE_ORDER(v)
    538        && v->BitsPerPixel==16
    539        && v->RedGamma==1.0 && v->GreenGamma==1.0 && v->BlueGamma==1.0) {
    540       /* 5-6-5 RGB */
    541       v->undithered_pf = PF_5R6G5B;
    542       v->dithered_pf = PF_Dither_5R6G5B;
    543    }
    544 }
    545 
    546 
    547 /**
    548  * When a context is bound for the first time, we can finally finish
    549  * initializing the context's visual and buffer information.
    550  * \param v  the XMesaVisual to initialize
    551  * \param b  the XMesaBuffer to initialize (may be NULL)
    552  * \param rgb_flag  TRUE = RGBA mode, FALSE = color index mode
    553  * \param window  the window/pixmap we're rendering into
    554  * \param cmap  the colormap associated with the window/pixmap
    555  * \return GL_TRUE=success, GL_FALSE=failure
    556  */
    557 static GLboolean
    558 initialize_visual_and_buffer(XMesaVisual v, XMesaBuffer b,
    559                              XMesaDrawable window,
    560                              XMesaColormap cmap)
    561 {
    562    const int xclass = v->visualType;
    563 
    564 
    565    ASSERT(!b || b->xm_visual == v);
    566 
    567    /* Save true bits/pixel */
    568    v->BitsPerPixel = bits_per_pixel(v);
    569    assert(v->BitsPerPixel > 0);
    570 
    571    /* RGB WINDOW:
    572     * We support RGB rendering into almost any kind of visual.
    573     */
    574    if (xclass == GLX_TRUE_COLOR || xclass == GLX_DIRECT_COLOR) {
    575       setup_truecolor( v, b, cmap );
    576    }
    577    else {
    578       _mesa_warning(NULL, "XMesa: RGB mode rendering not supported in given visual.\n");
    579       return GL_FALSE;
    580    }
    581    v->mesa_visual.indexBits = 0;
    582 
    583    if (_mesa_getenv("MESA_NO_DITHER")) {
    584       v->dithered_pf = v->undithered_pf;
    585    }
    586 
    587 
    588    /*
    589     * If MESA_INFO env var is set print out some debugging info
    590     * which can help Brian figure out what's going on when a user
    591     * reports bugs.
    592     */
    593    if (_mesa_getenv("MESA_INFO")) {
    594       printf("X/Mesa visual = %p\n", (void *) v);
    595       printf("X/Mesa dithered pf = %u\n", v->dithered_pf);
    596       printf("X/Mesa undithered pf = %u\n", v->undithered_pf);
    597       printf("X/Mesa level = %d\n", v->mesa_visual.level);
    598       printf("X/Mesa depth = %d\n", GET_VISUAL_DEPTH(v));
    599       printf("X/Mesa bits per pixel = %d\n", v->BitsPerPixel);
    600    }
    601 
    602    if (b && window) {
    603       /* Do window-specific initializations */
    604 
    605       /* these should have been set in create_xmesa_buffer */
    606       ASSERT(b->frontxrb->drawable == window);
    607       ASSERT(b->frontxrb->pixmap == (XMesaPixmap) window);
    608 
    609       /* Setup for single/double buffering */
    610       if (v->mesa_visual.doubleBufferMode) {
    611          /* Double buffered */
    612          b->shm = check_for_xshm( v->display );
    613       }
    614 
    615       /* X11 graphics contexts */
    616       b->gc = XCreateGC( v->display, window, 0, NULL );
    617       XMesaSetFunction( v->display, b->gc, GXcopy );
    618 
    619       /* cleargc - for glClear() */
    620       b->cleargc = XCreateGC( v->display, window, 0, NULL );
    621       XMesaSetFunction( v->display, b->cleargc, GXcopy );
    622 
    623       /*
    624        * Don't generate Graphics Expose/NoExpose events in swapbuffers().
    625        * Patch contributed by Michael Pichler May 15, 1995.
    626        */
    627       {
    628          XGCValues gcvalues;
    629          gcvalues.graphics_exposures = False;
    630          b->swapgc = XCreateGC(v->display, window,
    631                                GCGraphicsExposures, &gcvalues);
    632       }
    633       XMesaSetFunction( v->display, b->swapgc, GXcopy );
    634    }
    635 
    636    return GL_TRUE;
    637 }
    638 
    639 
    640 
    641 /*
    642  * Convert an RGBA color to a pixel value.
    643  */
    644 unsigned long
    645 xmesa_color_to_pixel(struct gl_context *ctx,
    646                      GLubyte r, GLubyte g, GLubyte b, GLubyte a,
    647                      GLuint pixelFormat)
    648 {
    649    XMesaContext xmesa = XMESA_CONTEXT(ctx);
    650    switch (pixelFormat) {
    651       case PF_Truecolor:
    652          {
    653             unsigned long p;
    654             PACK_TRUECOLOR( p, r, g, b );
    655             return p;
    656          }
    657       case PF_8A8B8G8R:
    658          return PACK_8A8B8G8R( r, g, b, a );
    659       case PF_8A8R8G8B:
    660          return PACK_8A8R8G8B( r, g, b, a );
    661       case PF_8R8G8B:
    662          /* fall through */
    663       case PF_8R8G8B24:
    664          return PACK_8R8G8B( r, g, b );
    665       case PF_5R6G5B:
    666          return PACK_5R6G5B( r, g, b );
    667       case PF_Dither_True:
    668          /* fall through */
    669       case PF_Dither_5R6G5B:
    670          {
    671             unsigned long p;
    672             PACK_TRUEDITHER(p, 1, 0, r, g, b);
    673             return p;
    674          }
    675       default:
    676          _mesa_problem(ctx, "Bad pixel format in xmesa_color_to_pixel");
    677    }
    678    return 0;
    679 }
    680 
    681 
    682 #define NUM_VISUAL_TYPES   6
    683 
    684 /**
    685  * Convert an X visual type to a GLX visual type.
    686  *
    687  * \param visualType X visual type (i.e., \c TrueColor, \c StaticGray, etc.)
    688  *        to be converted.
    689  * \return If \c visualType is a valid X visual type, a GLX visual type will
    690  *         be returned.  Otherwise \c GLX_NONE will be returned.
    691  *
    692  * \note
    693  * This code was lifted directly from lib/GL/glx/glcontextmodes.c in the
    694  * DRI CVS tree.
    695  */
    696 static GLint
    697 xmesa_convert_from_x_visual_type( int visualType )
    698 {
    699     static const int glx_visual_types[ NUM_VISUAL_TYPES ] = {
    700 	GLX_STATIC_GRAY,  GLX_GRAY_SCALE,
    701 	GLX_STATIC_COLOR, GLX_PSEUDO_COLOR,
    702 	GLX_TRUE_COLOR,   GLX_DIRECT_COLOR
    703     };
    704 
    705     return ( (unsigned) visualType < NUM_VISUAL_TYPES )
    706 	? glx_visual_types[ visualType ] : GLX_NONE;
    707 }
    708 
    709 
    710 /**********************************************************************/
    711 /*****                       Public Functions                     *****/
    712 /**********************************************************************/
    713 
    714 
    715 /*
    716  * Create a new X/Mesa visual.
    717  * Input:  display - X11 display
    718  *         visinfo - an XVisualInfo pointer
    719  *         rgb_flag - GL_TRUE = RGB mode,
    720  *                    GL_FALSE = color index mode
    721  *         alpha_flag - alpha buffer requested?
    722  *         db_flag - GL_TRUE = double-buffered,
    723  *                   GL_FALSE = single buffered
    724  *         stereo_flag - stereo visual?
    725  *         ximage_flag - GL_TRUE = use an XImage for back buffer,
    726  *                       GL_FALSE = use an off-screen pixmap for back buffer
    727  *         depth_size - requested bits/depth values, or zero
    728  *         stencil_size - requested bits/stencil values, or zero
    729  *         accum_red_size - requested bits/red accum values, or zero
    730  *         accum_green_size - requested bits/green accum values, or zero
    731  *         accum_blue_size - requested bits/blue accum values, or zero
    732  *         accum_alpha_size - requested bits/alpha accum values, or zero
    733  *         num_samples - number of samples/pixel if multisampling, or zero
    734  *         level - visual level, usually 0
    735  *         visualCaveat - ala the GLX extension, usually GLX_NONE
    736  * Return;  a new XMesaVisual or 0 if error.
    737  */
    738 PUBLIC
    739 XMesaVisual XMesaCreateVisual( XMesaDisplay *display,
    740                                XMesaVisualInfo visinfo,
    741                                GLboolean rgb_flag,
    742                                GLboolean alpha_flag,
    743                                GLboolean db_flag,
    744                                GLboolean stereo_flag,
    745                                GLboolean ximage_flag,
    746                                GLint depth_size,
    747                                GLint stencil_size,
    748                                GLint accum_red_size,
    749                                GLint accum_green_size,
    750                                GLint accum_blue_size,
    751                                GLint accum_alpha_size,
    752                                GLint num_samples,
    753                                GLint level,
    754                                GLint visualCaveat )
    755 {
    756    char *gamma;
    757    XMesaVisual v;
    758    GLint red_bits, green_bits, blue_bits, alpha_bits;
    759 
    760    /* For debugging only */
    761    if (_mesa_getenv("MESA_XSYNC")) {
    762       /* This makes debugging X easier.
    763        * In your debugger, set a breakpoint on _XError to stop when an
    764        * X protocol error is generated.
    765        */
    766       XSynchronize( display, 1 );
    767    }
    768 
    769    /* Color-index rendering not supported. */
    770    if (!rgb_flag)
    771       return NULL;
    772 
    773    v = (XMesaVisual) CALLOC_STRUCT(xmesa_visual);
    774    if (!v) {
    775       return NULL;
    776    }
    777 
    778    v->display = display;
    779 
    780    /* Save a copy of the XVisualInfo struct because the user may Xfree()
    781     * the struct but we may need some of the information contained in it
    782     * at a later time.
    783     */
    784    v->visinfo = (XVisualInfo *) MALLOC(sizeof(*visinfo));
    785    if(!v->visinfo) {
    786       free(v);
    787       return NULL;
    788    }
    789    memcpy(v->visinfo, visinfo, sizeof(*visinfo));
    790 
    791    /* check for MESA_GAMMA environment variable */
    792    gamma = _mesa_getenv("MESA_GAMMA");
    793    if (gamma) {
    794       v->RedGamma = v->GreenGamma = v->BlueGamma = 0.0;
    795       sscanf( gamma, "%f %f %f", &v->RedGamma, &v->GreenGamma, &v->BlueGamma );
    796       if (v->RedGamma<=0.0)    v->RedGamma = 1.0;
    797       if (v->GreenGamma<=0.0)  v->GreenGamma = v->RedGamma;
    798       if (v->BlueGamma<=0.0)   v->BlueGamma = v->RedGamma;
    799    }
    800    else {
    801       v->RedGamma = v->GreenGamma = v->BlueGamma = 1.0;
    802    }
    803 
    804    v->ximage_flag = ximage_flag;
    805 
    806    v->mesa_visual.redMask = visinfo->red_mask;
    807    v->mesa_visual.greenMask = visinfo->green_mask;
    808    v->mesa_visual.blueMask = visinfo->blue_mask;
    809    v->visualID = visinfo->visualid;
    810    v->screen = visinfo->screen;
    811 
    812 #if !(defined(__cplusplus) || defined(c_plusplus))
    813    v->visualType = xmesa_convert_from_x_visual_type(visinfo->class);
    814 #else
    815    v->visualType = xmesa_convert_from_x_visual_type(visinfo->c_class);
    816 #endif
    817 
    818    v->mesa_visual.visualRating = visualCaveat;
    819 
    820    if (alpha_flag)
    821       v->mesa_visual.alphaBits = 8;
    822 
    823    (void) initialize_visual_and_buffer( v, NULL, 0, 0 );
    824 
    825    {
    826       const int xclass = v->visualType;
    827       if (xclass == GLX_TRUE_COLOR || xclass == GLX_DIRECT_COLOR) {
    828          red_bits   = _mesa_bitcount(GET_REDMASK(v));
    829          green_bits = _mesa_bitcount(GET_GREENMASK(v));
    830          blue_bits  = _mesa_bitcount(GET_BLUEMASK(v));
    831       }
    832       else {
    833          /* this is an approximation */
    834          int depth;
    835          depth = GET_VISUAL_DEPTH(v);
    836          red_bits = depth / 3;
    837          depth -= red_bits;
    838          green_bits = depth / 2;
    839          depth -= green_bits;
    840          blue_bits = depth;
    841          alpha_bits = 0;
    842          assert( red_bits + green_bits + blue_bits == GET_VISUAL_DEPTH(v) );
    843       }
    844       alpha_bits = v->mesa_visual.alphaBits;
    845    }
    846 
    847    if (!_mesa_initialize_visual(&v->mesa_visual,
    848                                 db_flag, stereo_flag,
    849                                 red_bits, green_bits,
    850                                 blue_bits, alpha_bits,
    851                                 depth_size,
    852                                 stencil_size,
    853                                 accum_red_size, accum_green_size,
    854                                 accum_blue_size, accum_alpha_size,
    855                                 0)) {
    856       FREE(v);
    857       return NULL;
    858    }
    859 
    860    /* XXX minor hack */
    861    v->mesa_visual.level = level;
    862    return v;
    863 }
    864 
    865 
    866 PUBLIC
    867 void XMesaDestroyVisual( XMesaVisual v )
    868 {
    869    free(v->visinfo);
    870    free(v);
    871 }
    872 
    873 
    874 
    875 /**
    876  * Create a new XMesaContext.
    877  * \param v  the XMesaVisual
    878  * \param share_list  another XMesaContext with which to share display
    879  *                    lists or NULL if no sharing is wanted.
    880  * \return an XMesaContext or NULL if error.
    881  */
    882 PUBLIC
    883 XMesaContext XMesaCreateContext( XMesaVisual v, XMesaContext share_list )
    884 {
    885    static GLboolean firstTime = GL_TRUE;
    886    XMesaContext c;
    887    struct gl_context *mesaCtx;
    888    struct dd_function_table functions;
    889    TNLcontext *tnl;
    890 
    891    if (firstTime) {
    892       _glthread_INIT_MUTEX(_xmesa_lock);
    893       firstTime = GL_FALSE;
    894    }
    895 
    896    /* Note: the XMesaContext contains a Mesa struct gl_context struct (inheritance) */
    897    c = (XMesaContext) CALLOC_STRUCT(xmesa_context);
    898    if (!c)
    899       return NULL;
    900 
    901    mesaCtx = &(c->mesa);
    902 
    903    /* initialize with default driver functions, then plug in XMesa funcs */
    904    _mesa_init_driver_functions(&functions);
    905    xmesa_init_driver_functions(v, &functions);
    906    if (!_mesa_initialize_context(mesaCtx, API_OPENGL, &v->mesa_visual,
    907                       share_list ? &(share_list->mesa) : (struct gl_context *) NULL,
    908                       &functions, (void *) c)) {
    909       free(c);
    910       return NULL;
    911    }
    912 
    913    /* Enable this to exercise fixed function -> shader translation
    914     * with software rendering.
    915     */
    916    if (0) {
    917       mesaCtx->VertexProgram._MaintainTnlProgram = GL_TRUE;
    918       mesaCtx->FragmentProgram._MaintainTexEnvProgram = GL_TRUE;
    919    }
    920 
    921    _mesa_enable_sw_extensions(mesaCtx);
    922    _mesa_enable_1_3_extensions(mesaCtx);
    923    _mesa_enable_1_4_extensions(mesaCtx);
    924    _mesa_enable_1_5_extensions(mesaCtx);
    925    _mesa_enable_2_0_extensions(mesaCtx);
    926    _mesa_enable_2_1_extensions(mesaCtx);
    927     if (mesaCtx->Mesa_DXTn) {
    928        _mesa_enable_extension(mesaCtx, "GL_EXT_texture_compression_s3tc");
    929        _mesa_enable_extension(mesaCtx, "GL_S3_s3tc");
    930     }
    931     _mesa_enable_extension(mesaCtx, "GL_3DFX_texture_compression_FXT1");
    932 #if ENABLE_EXT_timer_query
    933     _mesa_enable_extension(mesaCtx, "GL_EXT_timer_query");
    934 #endif
    935 
    936 
    937    /* finish up xmesa context initializations */
    938    c->swapbytes = CHECK_BYTE_ORDER(v) ? GL_FALSE : GL_TRUE;
    939    c->xm_visual = v;
    940    c->xm_buffer = NULL;   /* set later by XMesaMakeCurrent */
    941    c->display = v->display;
    942    c->pixelformat = v->dithered_pf;      /* Dithering is enabled by default */
    943 
    944    /* Initialize the software rasterizer and helper modules.
    945     */
    946    if (!_swrast_CreateContext( mesaCtx ) ||
    947        !_vbo_CreateContext( mesaCtx ) ||
    948        !_tnl_CreateContext( mesaCtx ) ||
    949        !_swsetup_CreateContext( mesaCtx )) {
    950       _mesa_free_context_data(&c->mesa);
    951       free(c);
    952       return NULL;
    953    }
    954 
    955    /* tnl setup */
    956    tnl = TNL_CONTEXT(mesaCtx);
    957    tnl->Driver.RunPipeline = _tnl_run_pipeline;
    958    /* swrast setup */
    959    xmesa_register_swrast_functions( mesaCtx );
    960    _swsetup_Wakeup(mesaCtx);
    961 
    962    _mesa_meta_init(mesaCtx);
    963 
    964    return c;
    965 }
    966 
    967 
    968 
    969 PUBLIC
    970 void XMesaDestroyContext( XMesaContext c )
    971 {
    972    struct gl_context *mesaCtx = &c->mesa;
    973 
    974    _mesa_meta_free( mesaCtx );
    975 
    976    _swsetup_DestroyContext( mesaCtx );
    977    _swrast_DestroyContext( mesaCtx );
    978    _tnl_DestroyContext( mesaCtx );
    979    _vbo_DestroyContext( mesaCtx );
    980    _mesa_free_context_data( mesaCtx );
    981    free( c );
    982 }
    983 
    984 
    985 
    986 /**
    987  * Private function for creating an XMesaBuffer which corresponds to an
    988  * X window or pixmap.
    989  * \param v  the window's XMesaVisual
    990  * \param w  the window we're wrapping
    991  * \return  new XMesaBuffer or NULL if error
    992  */
    993 PUBLIC XMesaBuffer
    994 XMesaCreateWindowBuffer(XMesaVisual v, XMesaWindow w)
    995 {
    996    XWindowAttributes attr;
    997    XMesaBuffer b;
    998    XMesaColormap cmap;
    999    int depth;
   1000 
   1001    assert(v);
   1002    assert(w);
   1003 
   1004    /* Check that window depth matches visual depth */
   1005    XGetWindowAttributes( v->display, w, &attr );
   1006    depth = attr.depth;
   1007    if (GET_VISUAL_DEPTH(v) != depth) {
   1008       _mesa_warning(NULL, "XMesaCreateWindowBuffer: depth mismatch between visual (%d) and window (%d)!\n",
   1009                     GET_VISUAL_DEPTH(v), depth);
   1010       return NULL;
   1011    }
   1012 
   1013    /* Find colormap */
   1014    if (attr.colormap) {
   1015       cmap = attr.colormap;
   1016    }
   1017    else {
   1018       _mesa_warning(NULL, "Window %u has no colormap!\n", (unsigned int) w);
   1019       /* this is weird, a window w/out a colormap!? */
   1020       /* OK, let's just allocate a new one and hope for the best */
   1021       cmap = XCreateColormap(v->display, w, attr.visual, AllocNone);
   1022    }
   1023 
   1024    b = create_xmesa_buffer((XMesaDrawable) w, WINDOW, v, cmap);
   1025    if (!b)
   1026       return NULL;
   1027 
   1028    if (!initialize_visual_and_buffer( v, b, (XMesaDrawable) w, cmap )) {
   1029       xmesa_free_buffer(b);
   1030       return NULL;
   1031    }
   1032 
   1033    return b;
   1034 }
   1035 
   1036 
   1037 
   1038 /**
   1039  * Create a new XMesaBuffer from an X pixmap.
   1040  *
   1041  * \param v    the XMesaVisual
   1042  * \param p    the pixmap
   1043  * \param cmap the colormap, may be 0 if using a \c GLX_TRUE_COLOR or
   1044  *             \c GLX_DIRECT_COLOR visual for the pixmap
   1045  * \returns new XMesaBuffer or NULL if error
   1046  */
   1047 PUBLIC XMesaBuffer
   1048 XMesaCreatePixmapBuffer(XMesaVisual v, XMesaPixmap p, XMesaColormap cmap)
   1049 {
   1050    XMesaBuffer b;
   1051 
   1052    assert(v);
   1053 
   1054    b = create_xmesa_buffer((XMesaDrawable) p, PIXMAP, v, cmap);
   1055    if (!b)
   1056       return NULL;
   1057 
   1058    if (!initialize_visual_and_buffer(v, b, (XMesaDrawable) p, cmap)) {
   1059       xmesa_free_buffer(b);
   1060       return NULL;
   1061    }
   1062 
   1063    return b;
   1064 }
   1065 
   1066 
   1067 /**
   1068  * For GLX_EXT_texture_from_pixmap
   1069  */
   1070 XMesaBuffer
   1071 XMesaCreatePixmapTextureBuffer(XMesaVisual v, XMesaPixmap p,
   1072                                XMesaColormap cmap,
   1073                                int format, int target, int mipmap)
   1074 {
   1075    GET_CURRENT_CONTEXT(ctx);
   1076    XMesaBuffer b;
   1077    GLuint width, height;
   1078 
   1079    assert(v);
   1080 
   1081    b = create_xmesa_buffer((XMesaDrawable) p, PIXMAP, v, cmap);
   1082    if (!b)
   1083       return NULL;
   1084 
   1085    /* get pixmap size, update framebuffer/renderbuffer dims */
   1086    xmesa_get_window_size(v->display, b, &width, &height);
   1087    _mesa_resize_framebuffer(NULL, &(b->mesa_buffer), width, height);
   1088 
   1089    if (target == 0) {
   1090       /* examine dims */
   1091       if (ctx->Extensions.ARB_texture_non_power_of_two) {
   1092          target = GLX_TEXTURE_2D_EXT;
   1093       }
   1094       else if (   _mesa_bitcount(width)  == 1
   1095                && _mesa_bitcount(height) == 1) {
   1096          /* power of two size */
   1097          if (height == 1) {
   1098             target = GLX_TEXTURE_1D_EXT;
   1099          }
   1100          else {
   1101             target = GLX_TEXTURE_2D_EXT;
   1102          }
   1103       }
   1104       else if (ctx->Extensions.NV_texture_rectangle) {
   1105          target = GLX_TEXTURE_RECTANGLE_EXT;
   1106       }
   1107       else {
   1108          /* non power of two textures not supported */
   1109          XMesaDestroyBuffer(b);
   1110          return 0;
   1111       }
   1112    }
   1113 
   1114    b->TextureTarget = target;
   1115    b->TextureFormat = format;
   1116    b->TextureMipmap = mipmap;
   1117 
   1118    if (!initialize_visual_and_buffer(v, b, (XMesaDrawable) p, cmap)) {
   1119       xmesa_free_buffer(b);
   1120       return NULL;
   1121    }
   1122 
   1123    return b;
   1124 }
   1125 
   1126 
   1127 
   1128 XMesaBuffer
   1129 XMesaCreatePBuffer(XMesaVisual v, XMesaColormap cmap,
   1130                    unsigned int width, unsigned int height)
   1131 {
   1132    XMesaWindow root;
   1133    XMesaDrawable drawable;  /* X Pixmap Drawable */
   1134    XMesaBuffer b;
   1135 
   1136    /* allocate pixmap for front buffer */
   1137    root = RootWindow( v->display, v->visinfo->screen );
   1138    drawable = XCreatePixmap(v->display, root, width, height,
   1139                             v->visinfo->depth);
   1140    if (!drawable)
   1141       return NULL;
   1142 
   1143    b = create_xmesa_buffer(drawable, PBUFFER, v, cmap);
   1144    if (!b)
   1145       return NULL;
   1146 
   1147    if (!initialize_visual_and_buffer(v, b, drawable, cmap)) {
   1148       xmesa_free_buffer(b);
   1149       return NULL;
   1150    }
   1151 
   1152    return b;
   1153 }
   1154 
   1155 
   1156 
   1157 /*
   1158  * Deallocate an XMesaBuffer structure and all related info.
   1159  */
   1160 PUBLIC void
   1161 XMesaDestroyBuffer(XMesaBuffer b)
   1162 {
   1163    xmesa_free_buffer(b);
   1164 }
   1165 
   1166 
   1167 /**
   1168  * Query the current window size and update the corresponding struct gl_framebuffer
   1169  * and all attached renderbuffers.
   1170  * Called when:
   1171  *  1. the first time a buffer is bound to a context.
   1172  *  2. from glViewport to poll for window size changes
   1173  *  3. from the XMesaResizeBuffers() API function.
   1174  * Note: it's possible (and legal) for xmctx to be NULL.  That can happen
   1175  * when resizing a buffer when no rendering context is bound.
   1176  */
   1177 void
   1178 xmesa_check_and_update_buffer_size(XMesaContext xmctx, XMesaBuffer drawBuffer)
   1179 {
   1180    GLuint width, height;
   1181    xmesa_get_window_size(drawBuffer->display, drawBuffer, &width, &height);
   1182    if (drawBuffer->mesa_buffer.Width != width ||
   1183        drawBuffer->mesa_buffer.Height != height) {
   1184       struct gl_context *ctx = xmctx ? &xmctx->mesa : NULL;
   1185       _mesa_resize_framebuffer(ctx, &(drawBuffer->mesa_buffer), width, height);
   1186    }
   1187    drawBuffer->mesa_buffer.Initialized = GL_TRUE; /* XXX TEMPORARY? */
   1188 }
   1189 
   1190 
   1191 /*
   1192  * Bind buffer b to context c and make c the current rendering context.
   1193  */
   1194 GLboolean XMesaMakeCurrent( XMesaContext c, XMesaBuffer b )
   1195 {
   1196    return XMesaMakeCurrent2( c, b, b );
   1197 }
   1198 
   1199 
   1200 /*
   1201  * Bind buffer b to context c and make c the current rendering context.
   1202  */
   1203 PUBLIC
   1204 GLboolean XMesaMakeCurrent2( XMesaContext c, XMesaBuffer drawBuffer,
   1205                              XMesaBuffer readBuffer )
   1206 {
   1207    if (c) {
   1208       if (!drawBuffer || !readBuffer)
   1209          return GL_FALSE;  /* must specify buffers! */
   1210 
   1211       if (&(c->mesa) == _mesa_get_current_context()
   1212           && c->mesa.DrawBuffer == &drawBuffer->mesa_buffer
   1213           && c->mesa.ReadBuffer == &readBuffer->mesa_buffer
   1214           && XMESA_BUFFER(c->mesa.DrawBuffer)->wasCurrent) {
   1215          /* same context and buffer, do nothing */
   1216          return GL_TRUE;
   1217       }
   1218 
   1219       c->xm_buffer = drawBuffer;
   1220 
   1221       /* Call this periodically to detect when the user has begun using
   1222        * GL rendering from multiple threads.
   1223        */
   1224       _glapi_check_multithread();
   1225 
   1226       xmesa_check_and_update_buffer_size(c, drawBuffer);
   1227       if (readBuffer != drawBuffer)
   1228          xmesa_check_and_update_buffer_size(c, readBuffer);
   1229 
   1230       _mesa_make_current(&(c->mesa),
   1231                          &drawBuffer->mesa_buffer,
   1232                          &readBuffer->mesa_buffer);
   1233 
   1234       /*
   1235        * Must recompute and set these pixel values because colormap
   1236        * can be different for different windows.
   1237        */
   1238       c->clearpixel = xmesa_color_to_pixel( &c->mesa,
   1239 					    c->clearcolor[0],
   1240 					    c->clearcolor[1],
   1241 					    c->clearcolor[2],
   1242 					    c->clearcolor[3],
   1243 					    c->xm_visual->undithered_pf);
   1244       XMesaSetForeground(c->display, drawBuffer->cleargc, c->clearpixel);
   1245 
   1246       /* Solution to Stephane Rehel's problem with glXReleaseBuffersMESA(): */
   1247       drawBuffer->wasCurrent = GL_TRUE;
   1248    }
   1249    else {
   1250       /* Detach */
   1251       _mesa_make_current( NULL, NULL, NULL );
   1252    }
   1253    return GL_TRUE;
   1254 }
   1255 
   1256 
   1257 /*
   1258  * Unbind the context c from its buffer.
   1259  */
   1260 GLboolean XMesaUnbindContext( XMesaContext c )
   1261 {
   1262    /* A no-op for XFree86 integration purposes */
   1263    return GL_TRUE;
   1264 }
   1265 
   1266 
   1267 XMesaContext XMesaGetCurrentContext( void )
   1268 {
   1269    GET_CURRENT_CONTEXT(ctx);
   1270    if (ctx) {
   1271       XMesaContext xmesa = XMESA_CONTEXT(ctx);
   1272       return xmesa;
   1273    }
   1274    else {
   1275       return 0;
   1276    }
   1277 }
   1278 
   1279 
   1280 XMesaBuffer XMesaGetCurrentBuffer( void )
   1281 {
   1282    GET_CURRENT_CONTEXT(ctx);
   1283    if (ctx) {
   1284       XMesaBuffer xmbuf = XMESA_BUFFER(ctx->DrawBuffer);
   1285       return xmbuf;
   1286    }
   1287    else {
   1288       return 0;
   1289    }
   1290 }
   1291 
   1292 
   1293 /* New in Mesa 3.1 */
   1294 XMesaBuffer XMesaGetCurrentReadBuffer( void )
   1295 {
   1296    GET_CURRENT_CONTEXT(ctx);
   1297    if (ctx) {
   1298       return XMESA_BUFFER(ctx->ReadBuffer);
   1299    }
   1300    else {
   1301       return 0;
   1302    }
   1303 }
   1304 
   1305 
   1306 
   1307 GLboolean XMesaSetFXmode( GLint mode )
   1308 {
   1309    (void) mode;
   1310    return GL_FALSE;
   1311 }
   1312 
   1313 
   1314 
   1315 /*
   1316  * Copy the back buffer to the front buffer.  If there's no back buffer
   1317  * this is a no-op.
   1318  */
   1319 PUBLIC
   1320 void XMesaSwapBuffers( XMesaBuffer b )
   1321 {
   1322    GET_CURRENT_CONTEXT(ctx);
   1323 
   1324    if (!b->backxrb) {
   1325       /* single buffered */
   1326       return;
   1327    }
   1328 
   1329    /* If we're swapping the buffer associated with the current context
   1330     * we have to flush any pending rendering commands first.
   1331     */
   1332    if (ctx && ctx->DrawBuffer == &(b->mesa_buffer))
   1333       _mesa_notifySwapBuffers(ctx);
   1334 
   1335    if (b->db_mode) {
   1336       if (b->backxrb->ximage) {
   1337 	 /* Copy Ximage (back buf) from client memory to server window */
   1338 #if defined(USE_XSHM)
   1339 	 if (b->shm) {
   1340             /*_glthread_LOCK_MUTEX(_xmesa_lock);*/
   1341 	    XShmPutImage( b->xm_visual->display, b->frontxrb->drawable,
   1342 			  b->swapgc,
   1343 			  b->backxrb->ximage, 0, 0,
   1344 			  0, 0, b->mesa_buffer.Width, b->mesa_buffer.Height,
   1345                           False );
   1346             /*_glthread_UNLOCK_MUTEX(_xmesa_lock);*/
   1347 	 }
   1348 	 else
   1349 #endif
   1350          {
   1351             /*_glthread_LOCK_MUTEX(_xmesa_lock);*/
   1352             XMesaPutImage( b->xm_visual->display, b->frontxrb->drawable,
   1353 			   b->swapgc,
   1354 			   b->backxrb->ximage, 0, 0,
   1355 			   0, 0, b->mesa_buffer.Width, b->mesa_buffer.Height );
   1356             /*_glthread_UNLOCK_MUTEX(_xmesa_lock);*/
   1357          }
   1358       }
   1359       else if (b->backxrb->pixmap) {
   1360 	 /* Copy pixmap (back buf) to window (front buf) on server */
   1361          /*_glthread_LOCK_MUTEX(_xmesa_lock);*/
   1362 	 XMesaCopyArea( b->xm_visual->display,
   1363 			b->backxrb->pixmap,   /* source drawable */
   1364 			b->frontxrb->drawable,  /* dest. drawable */
   1365 			b->swapgc,
   1366 			0, 0, b->mesa_buffer.Width, b->mesa_buffer.Height,
   1367 			0, 0                 /* dest region */
   1368 		      );
   1369          /*_glthread_UNLOCK_MUTEX(_xmesa_lock);*/
   1370       }
   1371    }
   1372    XSync( b->xm_visual->display, False );
   1373 }
   1374 
   1375 
   1376 
   1377 /*
   1378  * Copy sub-region of back buffer to front buffer
   1379  */
   1380 void XMesaCopySubBuffer( XMesaBuffer b, int x, int y, int width, int height )
   1381 {
   1382    GET_CURRENT_CONTEXT(ctx);
   1383 
   1384    /* If we're swapping the buffer associated with the current context
   1385     * we have to flush any pending rendering commands first.
   1386     */
   1387    if (ctx && ctx->DrawBuffer == &(b->mesa_buffer))
   1388       _mesa_notifySwapBuffers(ctx);
   1389 
   1390    if (!b->backxrb) {
   1391       /* single buffered */
   1392       return;
   1393    }
   1394 
   1395    if (b->db_mode) {
   1396       int yTop = b->mesa_buffer.Height - y - height;
   1397       if (b->backxrb->ximage) {
   1398          /* Copy Ximage from host's memory to server's window */
   1399 #if defined(USE_XSHM)
   1400          if (b->shm) {
   1401             /* XXX assuming width and height aren't too large! */
   1402             XShmPutImage( b->xm_visual->display, b->frontxrb->drawable,
   1403                           b->swapgc,
   1404                           b->backxrb->ximage, x, yTop,
   1405                           x, yTop, width, height, False );
   1406             /* wait for finished event??? */
   1407          }
   1408          else
   1409 #endif
   1410          {
   1411             /* XXX assuming width and height aren't too large! */
   1412             XMesaPutImage( b->xm_visual->display, b->frontxrb->drawable,
   1413 			   b->swapgc,
   1414 			   b->backxrb->ximage, x, yTop,
   1415 			   x, yTop, width, height );
   1416          }
   1417       }
   1418       else {
   1419          /* Copy pixmap to window on server */
   1420          XMesaCopyArea( b->xm_visual->display,
   1421 			b->backxrb->pixmap,           /* source drawable */
   1422 			b->frontxrb->drawable,        /* dest. drawable */
   1423 			b->swapgc,
   1424 			x, yTop, width, height,  /* source region */
   1425 			x, yTop                  /* dest region */
   1426                       );
   1427       }
   1428    }
   1429 }
   1430 
   1431 
   1432 /*
   1433  * Return a pointer to the XMesa backbuffer Pixmap or XImage.  This function
   1434  * is a way to get "under the hood" of X/Mesa so one can manipulate the
   1435  * back buffer directly.
   1436  * Output:  pixmap - pointer to back buffer's Pixmap, or 0
   1437  *          ximage - pointer to back buffer's XImage, or NULL
   1438  * Return:  GL_TRUE = context is double buffered
   1439  *          GL_FALSE = context is single buffered
   1440  */
   1441 GLboolean XMesaGetBackBuffer( XMesaBuffer b,
   1442                               XMesaPixmap *pixmap,
   1443                               XMesaImage **ximage )
   1444 {
   1445    if (b->db_mode) {
   1446       if (pixmap)
   1447          *pixmap = b->backxrb->pixmap;
   1448       if (ximage)
   1449          *ximage = b->backxrb->ximage;
   1450       return GL_TRUE;
   1451    }
   1452    else {
   1453       *pixmap = 0;
   1454       *ximage = NULL;
   1455       return GL_FALSE;
   1456    }
   1457 }
   1458 
   1459 
   1460 /*
   1461  * Return the depth buffer associated with an XMesaBuffer.
   1462  * Input:  b - the XMesa buffer handle
   1463  * Output:  width, height - size of buffer in pixels
   1464  *          bytesPerValue - bytes per depth value (2 or 4)
   1465  *          buffer - pointer to depth buffer values
   1466  * Return:  GL_TRUE or GL_FALSE to indicate success or failure.
   1467  */
   1468 GLboolean XMesaGetDepthBuffer( XMesaBuffer b, GLint *width, GLint *height,
   1469                                GLint *bytesPerValue, void **buffer )
   1470 {
   1471    struct gl_renderbuffer *rb
   1472       = b->mesa_buffer.Attachment[BUFFER_DEPTH].Renderbuffer;
   1473    struct xmesa_renderbuffer *xrb = xmesa_renderbuffer(rb);
   1474 
   1475    if (!xrb || !xrb->Base.Buffer) {
   1476       *width = 0;
   1477       *height = 0;
   1478       *bytesPerValue = 0;
   1479       *buffer = 0;
   1480       return GL_FALSE;
   1481    }
   1482    else {
   1483       *width = b->mesa_buffer.Width;
   1484       *height = b->mesa_buffer.Height;
   1485       *bytesPerValue = b->mesa_buffer.Visual.depthBits <= 16
   1486          ? sizeof(GLushort) : sizeof(GLuint);
   1487       *buffer = (void *) xrb->Base.Buffer;
   1488       return GL_TRUE;
   1489    }
   1490 }
   1491 
   1492 
   1493 void XMesaFlush( XMesaContext c )
   1494 {
   1495    if (c && c->xm_visual) {
   1496       XSync( c->xm_visual->display, False );
   1497    }
   1498 }
   1499 
   1500 
   1501 
   1502 const char *XMesaGetString( XMesaContext c, int name )
   1503 {
   1504    (void) c;
   1505    if (name==XMESA_VERSION) {
   1506       return "5.0";
   1507    }
   1508    else if (name==XMESA_EXTENSIONS) {
   1509       return "";
   1510    }
   1511    else {
   1512       return NULL;
   1513    }
   1514 }
   1515 
   1516 
   1517 
   1518 XMesaBuffer XMesaFindBuffer( XMesaDisplay *dpy, XMesaDrawable d )
   1519 {
   1520    XMesaBuffer b;
   1521    for (b=XMesaBufferList; b; b=b->Next) {
   1522       if (b->frontxrb->drawable == d && b->display == dpy) {
   1523          return b;
   1524       }
   1525    }
   1526    return NULL;
   1527 }
   1528 
   1529 
   1530 /**
   1531  * Free/destroy all XMesaBuffers associated with given display.
   1532  */
   1533 void xmesa_destroy_buffers_on_display(XMesaDisplay *dpy)
   1534 {
   1535    XMesaBuffer b, next;
   1536    for (b = XMesaBufferList; b; b = next) {
   1537       next = b->Next;
   1538       if (b->display == dpy) {
   1539          xmesa_free_buffer(b);
   1540       }
   1541    }
   1542 }
   1543 
   1544 
   1545 /*
   1546  * Look for XMesaBuffers whose X window has been destroyed.
   1547  * Deallocate any such XMesaBuffers.
   1548  */
   1549 void XMesaGarbageCollect( XMesaDisplay* dpy )
   1550 {
   1551    XMesaBuffer b, next;
   1552    for (b=XMesaBufferList; b; b=next) {
   1553       next = b->Next;
   1554       if (b->display && b->display == dpy && b->frontxrb->drawable && b->type == WINDOW) {
   1555          XSync(b->display, False);
   1556          if (!window_exists( b->display, b->frontxrb->drawable )) {
   1557             /* found a dead window, free the ancillary info */
   1558             XMesaDestroyBuffer( b );
   1559          }
   1560       }
   1561    }
   1562 }
   1563 
   1564 
   1565 unsigned long XMesaDitherColor( XMesaContext xmesa, GLint x, GLint y,
   1566                                 GLfloat red, GLfloat green,
   1567                                 GLfloat blue, GLfloat alpha )
   1568 {
   1569    GLint r = (GLint) (red   * 255.0F);
   1570    GLint g = (GLint) (green * 255.0F);
   1571    GLint b = (GLint) (blue  * 255.0F);
   1572    GLint a = (GLint) (alpha * 255.0F);
   1573 
   1574    switch (xmesa->pixelformat) {
   1575       case PF_Truecolor:
   1576          {
   1577             unsigned long p;
   1578             PACK_TRUECOLOR( p, r, g, b );
   1579             return p;
   1580          }
   1581       case PF_8A8B8G8R:
   1582          return PACK_8A8B8G8R( r, g, b, a );
   1583       case PF_8A8R8G8B:
   1584          return PACK_8A8R8G8B( r, g, b, a );
   1585       case PF_8R8G8B:
   1586          return PACK_8R8G8B( r, g, b );
   1587       case PF_5R6G5B:
   1588          return PACK_5R6G5B( r, g, b );
   1589       case PF_Dither_5R6G5B:
   1590          /* fall through */
   1591       case PF_Dither_True:
   1592          {
   1593             unsigned long p;
   1594             PACK_TRUEDITHER(p, x, y, r, g, b);
   1595             return p;
   1596          }
   1597       default:
   1598          _mesa_problem(NULL, "Bad pixel format in XMesaDitherColor");
   1599    }
   1600    return 0;
   1601 }
   1602 
   1603 
   1604 /*
   1605  * This is typically called when the window size changes and we need
   1606  * to reallocate the buffer's back/depth/stencil/accum buffers.
   1607  */
   1608 PUBLIC void
   1609 XMesaResizeBuffers( XMesaBuffer b )
   1610 {
   1611    GET_CURRENT_CONTEXT(ctx);
   1612    XMesaContext xmctx = XMESA_CONTEXT(ctx);
   1613    if (!xmctx)
   1614       return;
   1615    xmesa_check_and_update_buffer_size(xmctx, b);
   1616 }
   1617 
   1618 
   1619 static GLint
   1620 xbuffer_to_renderbuffer(int buffer)
   1621 {
   1622    assert(MAX_AUX_BUFFERS <= 4);
   1623 
   1624    switch (buffer) {
   1625    case GLX_FRONT_LEFT_EXT:
   1626       return BUFFER_FRONT_LEFT;
   1627    case GLX_FRONT_RIGHT_EXT:
   1628       return BUFFER_FRONT_RIGHT;
   1629    case GLX_BACK_LEFT_EXT:
   1630       return BUFFER_BACK_LEFT;
   1631    case GLX_BACK_RIGHT_EXT:
   1632       return BUFFER_BACK_RIGHT;
   1633    case GLX_AUX0_EXT:
   1634       return BUFFER_AUX0;
   1635    case GLX_AUX1_EXT:
   1636    case GLX_AUX2_EXT:
   1637    case GLX_AUX3_EXT:
   1638    case GLX_AUX4_EXT:
   1639    case GLX_AUX5_EXT:
   1640    case GLX_AUX6_EXT:
   1641    case GLX_AUX7_EXT:
   1642    case GLX_AUX8_EXT:
   1643    case GLX_AUX9_EXT:
   1644    default:
   1645       /* BadValue error */
   1646       return -1;
   1647    }
   1648 }
   1649 
   1650 
   1651 PUBLIC void
   1652 XMesaBindTexImage(XMesaDisplay *dpy, XMesaBuffer drawable, int buffer,
   1653                   const int *attrib_list)
   1654 {
   1655 #if 0
   1656    GET_CURRENT_CONTEXT(ctx);
   1657    const GLuint unit = ctx->Texture.CurrentUnit;
   1658    struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
   1659    struct gl_texture_object *texObj;
   1660 #endif
   1661    struct gl_renderbuffer *rb;
   1662    struct xmesa_renderbuffer *xrb;
   1663    GLint b;
   1664    XMesaImage *img = NULL;
   1665    GLboolean freeImg = GL_FALSE;
   1666 
   1667    b = xbuffer_to_renderbuffer(buffer);
   1668    if (b < 0)
   1669       return;
   1670 
   1671    if (drawable->TextureFormat == GLX_TEXTURE_FORMAT_NONE_EXT)
   1672       return; /* BadMatch error */
   1673 
   1674    rb = drawable->mesa_buffer.Attachment[b].Renderbuffer;
   1675    if (!rb) {
   1676       /* invalid buffer */
   1677       return;
   1678    }
   1679    xrb = xmesa_renderbuffer(rb);
   1680 
   1681 #if 0
   1682    switch (drawable->TextureTarget) {
   1683    case GLX_TEXTURE_1D_EXT:
   1684       texObj = texUnit->CurrentTex[TEXTURE_1D_INDEX];
   1685       break;
   1686    case GLX_TEXTURE_2D_EXT:
   1687       texObj = texUnit->CurrentTex[TEXTURE_2D_INDEX];
   1688       break;
   1689    case GLX_TEXTURE_RECTANGLE_EXT:
   1690       texObj = texUnit->CurrentTex[TEXTURE_RECT_INDEX];
   1691       break;
   1692    default:
   1693       return; /* BadMatch error */
   1694    }
   1695 #endif
   1696 
   1697    /*
   1698     * The following is a quick and simple way to implement
   1699     * BindTexImage.  The better way is to write some new FetchTexel()
   1700     * functions which would extract texels from XImages.  We'd still
   1701     * need to use GetImage when texturing from a Pixmap (front buffer)
   1702     * but texturing from a back buffer (XImage) would avoid an image
   1703     * copy.
   1704     */
   1705 
   1706    /* get XImage */
   1707    if (xrb->pixmap) {
   1708       img = XMesaGetImage(dpy, xrb->pixmap, 0, 0, rb->Width, rb->Height, ~0L,
   1709 			  ZPixmap);
   1710       freeImg = GL_TRUE;
   1711    }
   1712    else if (xrb->ximage) {
   1713       img = xrb->ximage;
   1714    }
   1715 
   1716    /* store the XImage as a new texture image */
   1717    if (img) {
   1718       GLenum format, type, intFormat;
   1719       if (img->bits_per_pixel == 32) {
   1720          format = GL_BGRA;
   1721          type = GL_UNSIGNED_BYTE;
   1722          intFormat = GL_RGBA;
   1723       }
   1724       else if (img->bits_per_pixel == 24) {
   1725          format = GL_BGR;
   1726          type = GL_UNSIGNED_BYTE;
   1727          intFormat = GL_RGB;
   1728       }
   1729       else if (img->bits_per_pixel == 16) {
   1730          format = GL_BGR;
   1731          type = GL_UNSIGNED_SHORT_5_6_5;
   1732          intFormat = GL_RGB;
   1733       }
   1734       else {
   1735          _mesa_problem(NULL, "Unexpected XImage format in XMesaBindTexImage");
   1736          return;
   1737       }
   1738       if (drawable->TextureFormat == GLX_TEXTURE_FORMAT_RGBA_EXT) {
   1739          intFormat = GL_RGBA;
   1740       }
   1741       else if (drawable->TextureFormat == GLX_TEXTURE_FORMAT_RGB_EXT) {
   1742          intFormat = GL_RGB;
   1743       }
   1744 
   1745       _mesa_TexImage2D(GL_TEXTURE_2D, 0, intFormat, rb->Width, rb->Height, 0,
   1746                        format, type, img->data);
   1747 
   1748       if (freeImg) {
   1749 	 XMesaDestroyImage(img);
   1750       }
   1751    }
   1752 }
   1753 
   1754 
   1755 
   1756 PUBLIC void
   1757 XMesaReleaseTexImage(XMesaDisplay *dpy, XMesaBuffer drawable, int buffer)
   1758 {
   1759    const GLint b = xbuffer_to_renderbuffer(buffer);
   1760    if (b < 0)
   1761       return;
   1762 
   1763    /* no-op for now */
   1764 }
   1765 
   1766