xm_api.c

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

       * We'll use an alpha renderbuffer wrapper.
       */
      b->swAlpha = GL_TRUE;
   }
   else {
      b->swAlpha = GL_FALSE;
   }

   /*
    * Other renderbuffer (depth, stencil, etc)
    */
   _mesa_add_soft_renderbuffers(&b->mesa_buffer,
                                GL_FALSE,  /* color */
                                vis->mesa_visual.haveDepthBuffer,
                                vis->mesa_visual.haveStencilBuffer,
                                vis->mesa_visual.haveAccumBuffer,
                                b->swAlpha,
                                vis->mesa_visual.numAuxBuffers > 0 );

   /* GLX_EXT_texture_from_pixmap */
   b->TextureTarget = 0;
   b->TextureFormat = GLX_TEXTURE_FORMAT_NONE_EXT;
   b->TextureMipmap = 0;

   /* insert buffer into linked list */
   b->Next = XMesaBufferList;
   XMesaBufferList = b;

   return b;
}


/**
 * Find an XMesaBuffer by matching X display and colormap but NOT matching
 * the notThis buffer.
 */
XMesaBuffer
xmesa_find_buffer(XMesaDisplay *dpy, XMesaColormap cmap, XMesaBuffer notThis)
{
   XMesaBuffer b;
   for (b=XMesaBufferList; b; b=b->Next) {
      if (b->display==dpy && b->cmap==cmap && b!=notThis) {
         return b;
      }
   }
   return NULL;
}


/**
 * Remove buffer from linked list, delete if no longer referenced.
 */
static void
xmesa_free_buffer(XMesaBuffer buffer)
{
   XMesaBuffer prev = NULL, b;

   for (b = XMesaBufferList; b; b = b->Next) {
      if (b == buffer) {
         struct gl_framebuffer *fb = &buffer->mesa_buffer;

         /* unlink buffer from list */
         if (prev)
            prev->Next = buffer->Next;
         else
            XMesaBufferList = buffer->Next;

         /* mark as delete pending */
         fb->DeletePending = GL_TRUE;

         /* Since the X window for the XMesaBuffer is going away, we don't
          * want to dereference this pointer in the future.
          */
         b->frontxrb->drawable = 0;

         /* Unreference.  If count = zero we'll really delete the buffer */
         _mesa_unreference_framebuffer(&fb);

         return;
      }
      /* continue search */
      prev = b;
   }
   /* buffer not found in XMesaBufferList */
   _mesa_problem(NULL,"xmesa_free_buffer() - buffer not found\n");
}


/**
 * Copy X color table stuff from one XMesaBuffer to another.
 */
static void
copy_colortable_info(XMesaBuffer dst, const XMesaBuffer src)
{
   MEMCPY(dst->color_table, src->color_table, sizeof(src->color_table));
   MEMCPY(dst->pixel_to_r, src->pixel_to_r, sizeof(src->pixel_to_r));
   MEMCPY(dst->pixel_to_g, src->pixel_to_g, sizeof(src->pixel_to_g));
   MEMCPY(dst->pixel_to_b, src->pixel_to_b, sizeof(src->pixel_to_b));
   dst->num_alloced = src->num_alloced;
   MEMCPY(dst->alloced_colors, src->alloced_colors,
          sizeof(src->alloced_colors));
}



/**********************************************************************/
/*****                   Misc Private Functions                   *****/
/**********************************************************************/


/**
 * A replacement for XAllocColor.  This function should never
 * fail to allocate a color.  When XAllocColor fails, we return
 * the nearest matching color.  If we have to allocate many colors
 * this function isn't too efficient; the XQueryColors() could be
 * done just once.
 * Written by Michael Pichler, Brian Paul, Mark Kilgard
 * Input:  dpy - X display
 *         cmap - X colormap
 *         cmapSize - size of colormap
 * In/Out: color - the XColor struct
 * Output:  exact - 1=exact color match, 0=closest match
 *          alloced - 1=XAlloc worked, 0=XAlloc failed
 */
static void
noFaultXAllocColor( int client,
                    XMesaDisplay *dpy,
                    XMesaColormap cmap,
                    int cmapSize,
                    XMesaColor *color,
                    int *exact, int *alloced )
{
#ifdef XFree86Server
   Pixel *ppixIn;
   xrgb *ctable;
#else
   /* we'll try to cache ctable for better remote display performance */
   static Display *prevDisplay = NULL;
   static XMesaColormap prevCmap = 0;
   static int prevCmapSize = 0;
   static XMesaColor *ctable = NULL;
#endif
   XMesaColor subColor;
   int i, bestmatch;
   double mindist;       /* 3*2^16^2 exceeds long int precision. */

   (void) client;

   /* First try just using XAllocColor. */
#ifdef XFree86Server
   if (AllocColor(cmap,
		  &color->red, &color->green, &color->blue,
		  &color->pixel,
		  client) == Success)
#else
   if (XAllocColor(dpy, cmap, color))
#endif
   {
      *exact = 1;
      *alloced = 1;
      return;
   }

   /* Alloc failed, search for closest match */

   /* Retrieve color table entries. */
   /* XXX alloca candidate. */
#ifdef XFree86Server
   ppixIn = (Pixel *) MALLOC(cmapSize * sizeof(Pixel));
   ctable = (xrgb *) MALLOC(cmapSize * sizeof(xrgb));
   for (i = 0; i < cmapSize; i++) {
      ppixIn[i] = i;
   }
   QueryColors(cmap, cmapSize, ppixIn, ctable);
#else
   if (prevDisplay != dpy || prevCmap != cmap
       || prevCmapSize != cmapSize || !ctable) {
      /* free previously cached color table */
      if (ctable)
         _mesa_free(ctable);
      /* Get the color table from X */
      ctable = (XMesaColor *) MALLOC(cmapSize * sizeof(XMesaColor));
      assert(ctable);
      for (i = 0; i < cmapSize; i++) {
         ctable[i].pixel = i;
      }
      XQueryColors(dpy, cmap, ctable, cmapSize);
      prevDisplay = dpy;
      prevCmap = cmap;
      prevCmapSize = cmapSize;
   }
#endif

   /* Find best match. */
   bestmatch = -1;
   mindist = 0.0;
   for (i = 0; i < cmapSize; i++) {
      double dr = 0.30 * ((double) color->red - (double) ctable[i].red);
      double dg = 0.59 * ((double) color->green - (double) ctable[i].green);
      double db = 0.11 * ((double) color->blue - (double) ctable[i].blue);
      double dist = dr * dr + dg * dg + db * db;
      if (bestmatch < 0 || dist < mindist) {
         bestmatch = i;
         mindist = dist;
      }
   }

   /* Return result. */
   subColor.red   = ctable[bestmatch].red;
   subColor.green = ctable[bestmatch].green;
   subColor.blue  = ctable[bestmatch].blue;
   /* Try to allocate the closest match color.  This should only
    * fail if the cell is read/write.  Otherwise, we're incrementing
    * the cell's reference count.
    */
#ifdef XFree86Server
   if (AllocColor(cmap,
		  &subColor.red, &subColor.green, &subColor.blue,
		  &subColor.pixel,
		  client) == Success) {
#else
   if (XAllocColor(dpy, cmap, &subColor)) {
#endif
      *alloced = 1;
   }
   else {
      /* do this to work around a problem reported by Frank Ortega */
      subColor.pixel = (unsigned long) bestmatch;
      subColor.red   = ctable[bestmatch].red;
      subColor.green = ctable[bestmatch].green;
      subColor.blue  = ctable[bestmatch].blue;
      subColor.flags = DoRed | DoGreen | DoBlue;
      *alloced = 0;
   }
#ifdef XFree86Server
   _mesa_free(ppixIn);
   _mesa_free(ctable);
#else
   /* don't free table, save it for next time */
#endif

   *color = subColor;
   *exact = 0;
}



/**
 * Do setup for PF_GRAYSCALE pixel format.
 * Note that buffer may be NULL.
 */
static GLboolean
setup_grayscale(int client, XMesaVisual v,
                XMesaBuffer buffer, XMesaColormap cmap)
{
   if (GET_VISUAL_DEPTH(v)<4 || GET_VISUAL_DEPTH(v)>16) {
      return GL_FALSE;
   }

   if (buffer) {
      XMesaBuffer prevBuffer;

      if (!cmap) {
         return GL_FALSE;
      }

      prevBuffer = xmesa_find_buffer(v->display, cmap, buffer);
      if (prevBuffer &&
          (buffer->xm_visual->mesa_visual.rgbMode ==
           prevBuffer->xm_visual->mesa_visual.rgbMode)) {
         /* Copy colormap stuff from previous XMesaBuffer which uses same
          * X colormap.  Do this to avoid time spent in noFaultXAllocColor.
          */
         copy_colortable_info(buffer, prevBuffer);
      }
      else {
         /* Allocate 256 shades of gray */
         int gray;
         int colorsfailed = 0;
         for (gray=0;gray<256;gray++) {
            GLint r = gamma_adjust( v->RedGamma,   gray, 255 );
            GLint g = gamma_adjust( v->GreenGamma, gray, 255 );
            GLint b = gamma_adjust( v->BlueGamma,  gray, 255 );
            int exact, alloced;
            XMesaColor xcol;
            xcol.red   = (r << 8) | r;
            xcol.green = (g << 8) | g;
            xcol.blue  = (b << 8) | b;
            noFaultXAllocColor( client, v->display,
                                cmap, GET_COLORMAP_SIZE(v),
                                &xcol, &exact, &alloced );
            if (!exact) {
               colorsfailed++;
            }
            if (alloced) {
               assert(buffer->num_alloced<256);
               buffer->alloced_colors[buffer->num_alloced] = xcol.pixel;
               buffer->num_alloced++;
            }

            /*OLD
            assert(gray < 576);
            buffer->color_table[gray*3+0] = xcol.pixel;
            buffer->color_table[gray*3+1] = xcol.pixel;
            buffer->color_table[gray*3+2] = xcol.pixel;
            assert(xcol.pixel < 65536);
            buffer->pixel_to_r[xcol.pixel] = gray * 30 / 100;
            buffer->pixel_to_g[xcol.pixel] = gray * 59 / 100;
            buffer->pixel_to_b[xcol.pixel] = gray * 11 / 100;
            */
            buffer->color_table[gray] = xcol.pixel;
            assert(xcol.pixel < 65536);
            buffer->pixel_to_r[xcol.pixel] = gray;
            buffer->pixel_to_g[xcol.pixel] = gray;
            buffer->pixel_to_b[xcol.pixel] = gray;
         }

         if (colorsfailed && _mesa_getenv("MESA_DEBUG")) {
            _mesa_warning(NULL,
                  "Note: %d out of 256 needed colors do not match exactly.\n",
                  colorsfailed );
         }
      }
   }

   v->dithered_pf = PF_Grayscale;
   v->undithered_pf = PF_Grayscale;
   return GL_TRUE;
}



/**
 * Setup RGB rendering for a window with a PseudoColor, StaticColor,
 * or 8-bit TrueColor visual visual.  We try to allocate a palette of 225
 * colors (5 red, 9 green, 5 blue) and dither to approximate a 24-bit RGB
 * color.  While this function was originally designed just for 8-bit
 * visuals, it has also proven to work from 4-bit up to 16-bit visuals.
 * Dithering code contributed by Bob Mercier.
 */
static GLboolean
setup_dithered_color(int client, XMesaVisual v,
                     XMesaBuffer buffer, XMesaColormap cmap)
{
   if (GET_VISUAL_DEPTH(v)<4 || GET_VISUAL_DEPTH(v)>16) {
      return GL_FALSE;
   }

   if (buffer) {
      XMesaBuffer prevBuffer;

      if (!cmap) {
         return GL_FALSE;
      }

      prevBuffer = xmesa_find_buffer(v->display, cmap, buffer);
      if (prevBuffer &&
          (buffer->xm_visual->mesa_visual.rgbMode ==
           prevBuffer->xm_visual->mesa_visual.rgbMode)) {
         /* Copy colormap stuff from previous, matching XMesaBuffer.
          * Do this to avoid time spent in noFaultXAllocColor.
          */
         copy_colortable_info(buffer, prevBuffer);
      }
      else {
         /* Allocate X colors and initialize color_table[], red_table[], etc */
         int r, g, b, i;
         int colorsfailed = 0;
         for (r = 0; r < DITH_R; r++) {
            for (g = 0; g < DITH_G; g++) {
               for (b = 0; b < DITH_B; b++) {
                  XMesaColor xcol;
                  int exact, alloced;
                  xcol.red  =gamma_adjust(v->RedGamma,   r*65535/(DITH_R-1),65535);
                  xcol.green=gamma_adjust(v->GreenGamma, g*65535/(DITH_G-1),65535);
                  xcol.blue =gamma_adjust(v->BlueGamma,  b*65535/(DITH_B-1),65535);
                  noFaultXAllocColor( client, v->display,
                                      cmap, GET_COLORMAP_SIZE(v),
                                      &xcol, &exact, &alloced );
                  if (!exact) {
                     colorsfailed++;
                  }
                  if (alloced) {
                     assert(buffer->num_alloced<256);
                     buffer->alloced_colors[buffer->num_alloced] = xcol.pixel;
                     buffer->num_alloced++;
                  }
                  i = DITH_MIX( r, g, b );
                  assert(i < 576);
                  buffer->color_table[i] = xcol.pixel;
                  assert(xcol.pixel < 65536);
                  buffer->pixel_to_r[xcol.pixel] = r * 255 / (DITH_R-1);
                  buffer->pixel_to_g[xcol.pixel] = g * 255 / (DITH_G-1);
                  buffer->pixel_to_b[xcol.pixel] = b * 255 / (DITH_B-1);
               }
            }
         }

         if (colorsfailed && _mesa_getenv("MESA_DEBUG")) {
            _mesa_warning(NULL,
                  "Note: %d out of %d needed colors do not match exactly.\n",
                  colorsfailed, DITH_R * DITH_G * DITH_B );
         }
      }
   }

   v->dithered_pf = PF_Dither;
   v->undithered_pf = PF_Lookup;
   return GL_TRUE;
}


/**
 * Setup for Hewlett Packard Color Recovery 8-bit TrueColor mode.
 * HPCR simulates 24-bit color fidelity with an 8-bit frame buffer.
 * Special dithering tables have to be initialized.
 */
static void
setup_8bit_hpcr(XMesaVisual v)