fakeglx.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

*/
   return deepvis;
}


/**********************************************************************/
/***             Display-related functions                          ***/
/**********************************************************************/


/**
 * Free all XMesaVisuals which are associated with the given display.
 */
static void
destroy_visuals_on_display(Display *dpy)
{
   int i;
   for (i = 0; i < NumVisuals; i++) {
      if (VisualTable[i]->display == dpy) {
         /* remove this visual */
         int j;
         free(VisualTable[i]);
         for (j = i; j < NumVisuals - 1; j++)
            VisualTable[j] = VisualTable[j + 1];
         NumVisuals--;
      }
   }
}


/**
 * Called from XCloseDisplay() to let us free our display-related data.
 */
static int
close_display_callback(Display *dpy, XExtCodes *codes)
{
   destroy_visuals_on_display(dpy);
   xmesa_destroy_buffers_on_display(dpy);
   return 0;
}


/**
 * Look for the named extension on given display and return a pointer
 * to the _XExtension data, or NULL if extension not found.
 */
static _XExtension *
lookup_extension(Display *dpy, const char *extName)
{
   _XExtension *ext;
   for (ext = dpy->ext_procs; ext; ext = ext->next) {
      if (ext->name && strcmp(ext->name, extName) == 0) {
         return ext;
      }
   }
   return NULL;
}


/**
 * Whenever we're given a new Display pointer, call this function to
 * register our close_display_callback function.
 */
static void
register_with_display(Display *dpy)
{
   const char *extName = "MesaGLX";
   _XExtension *ext;

   ext = lookup_extension(dpy, extName);
   if (!ext) {
      XExtCodes *c = XAddExtension(dpy);
      ext = dpy->ext_procs;  /* new extension is at head of list */
      assert(c->extension == ext->codes.extension);
      ext->name = _mesa_strdup(extName);
      ext->close_display = close_display_callback;
   }
}


/**********************************************************************/
/***                  Begin Fake GLX API Functions                  ***/
/**********************************************************************/


/**
 * Helper used by glXChooseVisual and glXChooseFBConfig.
 * The fbConfig parameter must be GL_FALSE for the former and GL_TRUE for
 * the later.
 * In either case, the attribute list is terminated with the value 'None'.
 */
static XMesaVisual
choose_visual( Display *dpy, int screen, const int *list, GLboolean fbConfig )
{
   const GLboolean rgbModeDefault = fbConfig;
   const int *parselist;
   XVisualInfo *vis;
   int min_ci = 0;
   int min_red=0, min_green=0, min_blue=0;
   GLboolean rgb_flag = rgbModeDefault;
   GLboolean alpha_flag = GL_FALSE;
   GLboolean double_flag = GL_FALSE;
   GLboolean stereo_flag = GL_FALSE;
   GLint depth_size = 0;
   GLint stencil_size = 0;
   GLint accumRedSize = 0;
   GLint accumGreenSize = 0;
   GLint accumBlueSize = 0;
   GLint accumAlphaSize = 0;
   int level = 0;
   int visual_type = DONT_CARE;
   int trans_type = DONT_CARE;
   int trans_value = DONT_CARE;
   GLint caveat = DONT_CARE;
   XMesaVisual xmvis = NULL;
   int desiredVisualID = -1;
   int numAux = 0;

   parselist = list;

   while (*parselist) {

      switch (*parselist) {
	 case GLX_USE_GL:
            if (fbConfig) {
               /* invalid token */
               return NULL;
            }
            else {
               /* skip */
               parselist++;
            }
	    break;
	 case GLX_BUFFER_SIZE:
	    parselist++;
	    min_ci = *parselist++;
	    break;
	 case GLX_LEVEL:
	    parselist++;
            level = *parselist++;
	    break;
	 case GLX_RGBA:
            if (fbConfig) {
               /* invalid token */
               return NULL;
            }
            else {
               rgb_flag = GL_TRUE;
               parselist++;
            }
	    break;
	 case GLX_DOUBLEBUFFER:
            parselist++;
            if (fbConfig) {
               double_flag = *parselist++;
            }
            else {
               double_flag = GL_TRUE;
            }
	    break;
	 case GLX_STEREO:
            parselist++;
            if (fbConfig) {
               stereo_flag = *parselist++;
            }
            else {
               stereo_flag = GL_TRUE;
            }
            break;
	 case GLX_AUX_BUFFERS:
	    parselist++;
            numAux = *parselist++;
            if (numAux > MAX_AUX_BUFFERS)
               return NULL;
	    break;
	 case GLX_RED_SIZE:
	    parselist++;
	    min_red = *parselist++;
	    break;
	 case GLX_GREEN_SIZE:
	    parselist++;
	    min_green = *parselist++;
	    break;
	 case GLX_BLUE_SIZE:
	    parselist++;
	    min_blue = *parselist++;
	    break;
	 case GLX_ALPHA_SIZE:
	    parselist++;
            {
               GLint size = *parselist++;
               alpha_flag = size ? GL_TRUE : GL_FALSE;
            }
	    break;
	 case GLX_DEPTH_SIZE:
	    parselist++;
	    depth_size = *parselist++;
	    break;
	 case GLX_STENCIL_SIZE:
	    parselist++;
	    stencil_size = *parselist++;
	    break;
	 case GLX_ACCUM_RED_SIZE:
	    parselist++;
            {
               GLint size = *parselist++;
               accumRedSize = MAX2( accumRedSize, size );
            }
            break;
	 case GLX_ACCUM_GREEN_SIZE:
	    parselist++;
            {
               GLint size = *parselist++;
               accumGreenSize = MAX2( accumGreenSize, size );
            }
            break;
	 case GLX_ACCUM_BLUE_SIZE:
	    parselist++;
            {
               GLint size = *parselist++;
               accumBlueSize = MAX2( accumBlueSize, size );
            }
            break;
	 case GLX_ACCUM_ALPHA_SIZE:
	    parselist++;
            {
               GLint size = *parselist++;
               accumAlphaSize = MAX2( accumAlphaSize, size );
            }
	    break;

         /*
          * GLX_EXT_visual_info extension
          */
         case GLX_X_VISUAL_TYPE_EXT:
            parselist++;
            visual_type = *parselist++;
            break;
         case GLX_TRANSPARENT_TYPE_EXT:
            parselist++;
            trans_type = *parselist++;
            break;
         case GLX_TRANSPARENT_INDEX_VALUE_EXT:
            parselist++;
            trans_value = *parselist++;
            break;
         case GLX_TRANSPARENT_RED_VALUE_EXT:
         case GLX_TRANSPARENT_GREEN_VALUE_EXT:
         case GLX_TRANSPARENT_BLUE_VALUE_EXT:
         case GLX_TRANSPARENT_ALPHA_VALUE_EXT:
	    /* ignore */
	    parselist++;
	    parselist++;
	    break;

         /*
          * GLX_EXT_visual_info extension
          */
         case GLX_VISUAL_CAVEAT_EXT:
            parselist++;
            caveat = *parselist++; /* ignored for now */
            break;

         /*
          * GLX_ARB_multisample
          */
         case GLX_SAMPLE_BUFFERS_ARB:
         case GLX_SAMPLES_ARB:
	    parselist++;
	    if (*parselist++ != 0)
	       /* ms not supported */
	       return NULL;
	    break;

         /*
          * FBConfig attribs.
          */
         case GLX_RENDER_TYPE:
            if (!fbConfig)
               return NULL;
            parselist++;
            if (*parselist == GLX_RGBA_BIT) {
               rgb_flag = GL_TRUE;
            }
            else if (*parselist == GLX_COLOR_INDEX_BIT) {
               rgb_flag = GL_FALSE;
            }
            else if (*parselist == 0) {
               rgb_flag = GL_TRUE;
            }
            parselist++;
            break;
         case GLX_DRAWABLE_TYPE:
            if (!fbConfig)
               return NULL;
            parselist++;
            if (*parselist & ~(GLX_WINDOW_BIT | GLX_PIXMAP_BIT | GLX_PBUFFER_BIT)) {
               return NULL; /* bad bit */
            }
            parselist++;
            break;
         case GLX_FBCONFIG_ID:
            if (!fbConfig)
               return NULL;
            parselist++;
            desiredVisualID = *parselist++;
            break;
         case GLX_X_RENDERABLE:
            if (!fbConfig)
               return NULL;
            parselist += 2;
            /* ignore */
            break;

#ifdef GLX_EXT_texture_from_pixmap
         case GLX_BIND_TO_TEXTURE_RGB_EXT:
            parselist++; /*skip*/
            break;
         case GLX_BIND_TO_TEXTURE_RGBA_EXT:
            parselist++; /*skip*/
            break;
         case GLX_BIND_TO_MIPMAP_TEXTURE_EXT:
            parselist++; /*skip*/
            break;
         case GLX_BIND_TO_TEXTURE_TARGETS_EXT:
            parselist++;
            if (*parselist & ~(GLX_TEXTURE_1D_BIT_EXT |
                               GLX_TEXTURE_2D_BIT_EXT |
                               GLX_TEXTURE_RECTANGLE_BIT_EXT)) {
               /* invalid bit */
               return NULL;
            }
            break;
         case GLX_Y_INVERTED_EXT:
            parselist++; /*skip*/
            break;
#endif

	 case None:
            /* end of list */
	    break;

	 default:
	    /* undefined attribute */
            _mesa_warning(NULL, "unexpected attrib 0x%x in choose_visual()",
                          *parselist);
	    return NULL;
      }
   }

   (void) caveat;

   /*
    * Since we're only simulating the GLX extension this function will never
    * find any real GL visuals.  Instead, all we can do is try to find an RGB
    * or CI visual of appropriate depth.  Other requested attributes such as
    * double buffering, depth buffer, etc. will be associated with the X
    * visual and stored in the VisualTable[].
    */
   if (desiredVisualID != -1) {
      /* try to get a specific visual, by visualID */
      XVisualInfo temp;
      int n;
      temp.visualid = desiredVisualID;
      temp.screen = screen;
      vis = XGetVisualInfo(dpy, VisualIDMask | VisualScreenMask, &temp, &n);
      if (vis) {
         /* give the visual some useful GLX attributes */
         double_flag = GL_TRUE;
         if (vis->depth > 8)
            rgb_flag = GL_TRUE;
         depth_size = default_depth_bits();
         stencil_size = STENCIL_BITS;
         /* XXX accum??? */
      }
   }
   else if (level==0) {
      /* normal color planes */
      if (rgb_flag) {
         /* Get an RGB visual */
         int min_rgb = min_red + min_green + min_blue;
         if (min_rgb>1 && min_rgb<8) {
            /* a special case to be sure we can get a monochrome visual */
            min_rgb = 1;
         }
         vis = choose_x_visual( dpy, screen, rgb_flag, min_rgb, visual_type );
      }
      else {
         /* Get a color index visual */
         vis = choose_x_visual( dpy, screen, rgb_flag, min_ci, visual_type );
         accumRedSize = accumGreenSize = accumBlueSize = accumAlphaSize = 0;
      }
   }
   else {
      /* over/underlay planes */
      if (rgb_flag) {
         /* rgba overlay */
         int min_rgb = min_red + min_green + min_blue;
         if (min_rgb>1 && min_rgb<8) {
            /* a special case to be sure we can get a monochrome visual */
            min_rgb = 1;
         }
         vis = choose_x_overlay_visual( dpy, screen, rgb_flag, level,
                              trans_type, trans_value, min_rgb, visual_type );
      }
      else {
         /* color index overlay */
         vis = choose_x_overlay_visual( dpy, screen, rgb_flag, level,
                              trans_type, trans_value, min_ci, visual_type );
      }
   }

   if (vis) {
      /* Note: we're not exactly obeying the glXChooseVisual rules here.
       * When GLX_DEPTH_SIZE = 1 is specified we're supposed to choose the
       * largest depth buffer size, which is 32bits/value.  Instead, we
       * return 16 to maintain performance with earlier versions of Mesa.
       */
      if (depth_size > 24)
         depth_size = 32;
      else if (depth_size > 16)
         depth_size = 24;
      else if (depth_size > 0) {
         depth_size = default_depth_bits();
      }

      if (!alpha_flag) {
         alpha_flag = default_alpha_bits() > 0;
      }

      /* we only support one size of stencil and accum buffers. */
      if (stencil_size > 0)
         stencil_size = STENCIL_BITS;
      if (accumRedSize > 0 || accumGreenSize > 0 || accumBlueSize > 0 ||
          accumAlphaSize > 0) {
         accumRedSize = 
         accumGreenSize = 
         accumBlueSize = default_accum_bits();
         accumAlphaSize = alpha_flag ? accumRedSize : 0;
      }

      xmvis = save_glx_visual( dpy, vis, rgb_flag, alpha_flag, double_flag,
                               stereo_flag, depth_size, stencil_size,
                               accumRedSize, accumGreenSize,
                               accumBlueSize, accumAlphaSize, level, numAux );
   }

   return xmvis;
}


static XVisualInfo *
Fake_glXChooseVisual( Display *dpy, int screen, int *list )
{
   XMesaVisual xmvis;

   /* register ourselves as an extension on this display */
   register_with_display(dpy);