xm_api.c

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

{
   /* HP Color Recovery contributed by:  Alex De Bruyn ([e-mail])
    * To work properly, the atom _HP_RGB_SMOOTH_MAP_LIST must be defined
    * on the root window AND the colormap obtainable by XGetRGBColormaps
    * for that atom must be set on the window.  (see also tkInitWindow)
    * If that colormap is not set, the output will look stripy.
    */

   /* Setup color tables with gamma correction */
   int i;
   double g;

   g = 1.0 / v->RedGamma;
   for (i=0; i<256; i++) {
      GLint red = IROUND_POS(255.0 * _mesa_pow( hpcr_rgbTbl[0][i]/255.0, g ));
      v->hpcr_rgbTbl[0][i] = CLAMP( red, 16, 239 );
   }

   g = 1.0 / v->GreenGamma;
   for (i=0; i<256; i++) {
      GLint green = IROUND_POS(255.0 * _mesa_pow( hpcr_rgbTbl[1][i]/255.0, g ));
      v->hpcr_rgbTbl[1][i] = CLAMP( green, 16, 239 );
   }

   g = 1.0 / v->BlueGamma;
   for (i=0; i<256; i++) {
      GLint blue = IROUND_POS(255.0 * _mesa_pow( hpcr_rgbTbl[2][i]/255.0, g ));
      v->hpcr_rgbTbl[2][i] = CLAMP( blue, 32, 223 );
   }
   v->undithered_pf = PF_HPCR;  /* can't really disable dithering for now */
   v->dithered_pf = PF_HPCR;

   /* which method should I use to clear */
   /* GL_FALSE: keep the ordinary method  */
   /* GL_TRUE : clear with dither pattern */
   v->hpcr_clear_flag = _mesa_getenv("MESA_HPCR_CLEAR") ? GL_TRUE : GL_FALSE;

   if (v->hpcr_clear_flag) {
      v->hpcr_clear_pixmap = XMesaCreatePixmap(v->display,
                                               DefaultRootWindow(v->display),
                                               16, 2, 8);
#ifndef XFree86Server
      v->hpcr_clear_ximage = XGetImage(v->display, v->hpcr_clear_pixmap,
                                       0, 0, 16, 2, AllPlanes, ZPixmap);
#endif
   }
}


/**
 * Setup RGB rendering for a window with a True/DirectColor visual.
 */
static void
setup_truecolor(XMesaVisual v, XMesaBuffer buffer, XMesaColormap cmap)
{
   unsigned long rmask, gmask, bmask;
   (void) buffer;
   (void) cmap;

   /* Compute red multiplier (mask) and bit shift */
   v->rshift = 0;
   rmask = GET_REDMASK(v);
   while ((rmask & 1)==0) {
      v->rshift++;
      rmask = rmask >> 1;
   }

   /* Compute green multiplier (mask) and bit shift */
   v->gshift = 0;
   gmask = GET_GREENMASK(v);
   while ((gmask & 1)==0) {
      v->gshift++;
      gmask = gmask >> 1;
   }

   /* Compute blue multiplier (mask) and bit shift */
   v->bshift = 0;
   bmask = GET_BLUEMASK(v);
   while ((bmask & 1)==0) {
      v->bshift++;
      bmask = bmask >> 1;
   }

   /*
    * Compute component-to-pixel lookup tables and dithering kernel
    */
   {
      static GLubyte kernel[16] = {
          0*16,  8*16,  2*16, 10*16,
         12*16,  4*16, 14*16,  6*16,
          3*16, 11*16,  1*16,  9*16,
         15*16,  7*16, 13*16,  5*16,
      };
      GLint rBits = _mesa_bitcount(rmask);
      GLint gBits = _mesa_bitcount(gmask);
      GLint bBits = _mesa_bitcount(bmask);
      GLint maxBits;
      GLuint i;

      /* convert pixel components in [0,_mask] to RGB values in [0,255] */
      for (i=0; i<=rmask; i++)
         v->PixelToR[i] = (unsigned char) ((i * 255) / rmask);
      for (i=0; i<=gmask; i++)
         v->PixelToG[i] = (unsigned char) ((i * 255) / gmask);
      for (i=0; i<=bmask; i++)
         v->PixelToB[i] = (unsigned char) ((i * 255) / bmask);

      /* convert RGB values from [0,255] to pixel components */

      for (i=0;i<256;i++) {
         GLint r = gamma_adjust(v->RedGamma,   i, 255);
         GLint g = gamma_adjust(v->GreenGamma, i, 255);
         GLint b = gamma_adjust(v->BlueGamma,  i, 255);
         v->RtoPixel[i] = (r >> (8-rBits)) << v->rshift;
         v->GtoPixel[i] = (g >> (8-gBits)) << v->gshift;
         v->BtoPixel[i] = (b >> (8-bBits)) << v->bshift;
      }
      /* overflow protection */
      for (i=256;i<512;i++) {
         v->RtoPixel[i] = v->RtoPixel[255];
         v->GtoPixel[i] = v->GtoPixel[255];
         v->BtoPixel[i] = v->BtoPixel[255];
      }

      /* setup dithering kernel */
      maxBits = rBits;
      if (gBits > maxBits)  maxBits = gBits;
      if (bBits > maxBits)  maxBits = bBits;
      for (i=0;i<16;i++) {
         v->Kernel[i] = kernel[i] >> maxBits;
      }

      v->undithered_pf = PF_Truecolor;
      v->dithered_pf = (GET_VISUAL_DEPTH(v)<24) ? PF_Dither_True : PF_Truecolor;
   }

   /*
    * Now check for TrueColor visuals which we can optimize.
    */
   if (   GET_REDMASK(v)  ==0x0000ff
       && GET_GREENMASK(v)==0x00ff00
       && GET_BLUEMASK(v) ==0xff0000
       && CHECK_BYTE_ORDER(v)
       && v->BitsPerPixel==32
       && v->RedGamma==1.0 && v->GreenGamma==1.0 && v->BlueGamma==1.0) {
      /* common 32 bpp config used on SGI, Sun */
      v->undithered_pf = v->dithered_pf = PF_8A8B8G8R; /* ABGR */
   }
   else if (GET_REDMASK(v)  == 0xff0000
         && GET_GREENMASK(v)== 0x00ff00
         && GET_BLUEMASK(v) == 0x0000ff
         && CHECK_BYTE_ORDER(v)
         && v->RedGamma == 1.0 && v->GreenGamma == 1.0 && v->BlueGamma == 1.0){
      if (v->BitsPerPixel==32) {
         /* if 32 bpp, and visual indicates 8 bpp alpha channel */
         if (GET_VISUAL_DEPTH(v) == 32 && v->mesa_visual.alphaBits == 8)
            v->undithered_pf = v->dithered_pf = PF_8A8R8G8B; /* ARGB */
         else
            v->undithered_pf = v->dithered_pf = PF_8R8G8B; /* xRGB */
      }
      else if (v->BitsPerPixel == 24) {
         v->undithered_pf = v->dithered_pf = PF_8R8G8B24; /* RGB */
      }
   }
   else if (GET_REDMASK(v)  ==0xf800
       &&   GET_GREENMASK(v)==0x07e0
       &&   GET_BLUEMASK(v) ==0x001f
       && CHECK_BYTE_ORDER(v)
       && v->BitsPerPixel==16
       && v->RedGamma==1.0 && v->GreenGamma==1.0 && v->BlueGamma==1.0) {
      /* 5-6-5 RGB */
      v->undithered_pf = PF_5R6G5B;
      v->dithered_pf = PF_Dither_5R6G5B;
   }
   else if (GET_REDMASK(v)  ==0xe0
       &&   GET_GREENMASK(v)==0x1c
       &&   GET_BLUEMASK(v) ==0x03
       && CHECK_FOR_HPCR(v)) {
      /* 8-bit HP color recovery */
      setup_8bit_hpcr( v );
   }
}



/**
 * Setup RGB rendering for a window with a monochrome visual.
 */
static void
setup_monochrome( XMesaVisual v, XMesaBuffer b )
{
   (void) b;
   v->dithered_pf = v->undithered_pf = PF_1Bit;
   /* if black=1 then we must flip pixel values */
   v->bitFlip = (GET_BLACK_PIXEL(v) != 0);
}



/**
 * When a context is bound for the first time, we can finally finish
 * initializing the context's visual and buffer information.
 * \param v  the XMesaVisual to initialize
 * \param b  the XMesaBuffer to initialize (may be NULL)
 * \param rgb_flag  TRUE = RGBA mode, FALSE = color index mode
 * \param window  the window/pixmap we're rendering into
 * \param cmap  the colormap associated with the window/pixmap
 * \return GL_TRUE=success, GL_FALSE=failure
 */
static GLboolean
initialize_visual_and_buffer(XMesaVisual v, XMesaBuffer b,
                             GLboolean rgb_flag, XMesaDrawable window,
                             XMesaColormap cmap)
{
   int client = 0;

#ifdef XFree86Server
   client = (window) ? CLIENT_ID(window->id) : 0;
#endif

   ASSERT(!b || b->xm_visual == v);

   /* Save true bits/pixel */
   v->BitsPerPixel = bits_per_pixel(v);
   assert(v->BitsPerPixel > 0);

   if (rgb_flag == GL_FALSE) {
      /* COLOR-INDEXED WINDOW:
       * Even if the visual is TrueColor or DirectColor we treat it as
       * being color indexed.  This is weird but might be useful to someone.
       */
      v->dithered_pf = v->undithered_pf = PF_Index;
      v->mesa_visual.indexBits = GET_VISUAL_DEPTH(v);
   }
   else {
      /* RGB WINDOW:
       * We support RGB rendering into almost any kind of visual.
       */
      const int xclass = v->mesa_visual.visualType;
      if (xclass == GLX_TRUE_COLOR || xclass == GLX_DIRECT_COLOR) {
	 setup_truecolor( v, b, cmap );
      }
      else if (xclass == GLX_STATIC_GRAY && GET_VISUAL_DEPTH(v) == 1) {
	 setup_monochrome( v, b );
      }
      else if (xclass == GLX_GRAY_SCALE || xclass == GLX_STATIC_GRAY) {
         if (!setup_grayscale( client, v, b, cmap )) {
            return GL_FALSE;
         }
      }
      else if ((xclass == GLX_PSEUDO_COLOR || xclass == GLX_STATIC_COLOR)
               && GET_VISUAL_DEPTH(v)>=4 && GET_VISUAL_DEPTH(v)<=16) {
	 if (!setup_dithered_color( client, v, b, cmap )) {
            return GL_FALSE;
         }
      }
      else {
	 _mesa_warning(NULL, "XMesa: RGB mode rendering not supported in given visual.\n");
	 return GL_FALSE;
      }
      v->mesa_visual.indexBits = 0;

      if (_mesa_getenv("MESA_NO_DITHER")) {
	 v->dithered_pf = v->undithered_pf;
      }
   }


   /*
    * If MESA_INFO env var is set print out some debugging info
    * which can help Brian figure out what's going on when a user
    * reports bugs.
    */
   if (_mesa_getenv("MESA_INFO")) {
      _mesa_printf("X/Mesa visual = %p\n", (void *) v);
      _mesa_printf("X/Mesa dithered pf = %u\n", v->dithered_pf);
      _mesa_printf("X/Mesa undithered pf = %u\n", v->undithered_pf);
      _mesa_printf("X/Mesa level = %d\n", v->mesa_visual.level);
      _mesa_printf("X/Mesa depth = %d\n", GET_VISUAL_DEPTH(v));
      _mesa_printf("X/Mesa bits per pixel = %d\n", v->BitsPerPixel);
   }

   if (b && window) {
      char *data;

      /* Do window-specific initializations */

      /* these should have been set in create_xmesa_buffer */
      ASSERT(b->frontxrb->drawable == window);
      ASSERT(b->frontxrb->pixmap == (XMesaPixmap) window);

      /* Setup for single/double buffering */
      if (v->mesa_visual.doubleBufferMode) {
         /* Double buffered */
         b->shm = check_for_xshm( v->display );
      }

      /* X11 graphics contexts */
#ifdef XFree86Server
      b->gc = CreateScratchGC(v->display, window->depth);
#else
      b->gc = XCreateGC( v->display, window, 0, NULL );
#endif
      XMesaSetFunction( v->display, b->gc, GXcopy );

      /* cleargc - for glClear() */
#ifdef XFree86Server
      b->cleargc = CreateScratchGC(v->display, window->depth);
#else
      b->cleargc = XCreateGC( v->display, window, 0, NULL );
#endif
      XMesaSetFunction( v->display, b->cleargc, GXcopy );

      /*
       * Don't generate Graphics Expose/NoExpose events in swapbuffers().
       * Patch contributed by Michael Pichler May 15, 1995.
       */
#ifdef XFree86Server
      b->swapgc = CreateScratchGC(v->display, window->depth);
      {
         CARD32 v[1];
         v[0] = FALSE;
         dixChangeGC(NullClient, b->swapgc, GCGraphicsExposures, v, NULL);
      }
#else
      {
         XGCValues gcvalues;
         gcvalues.graphics_exposures = False;
         b->swapgc = XCreateGC(v->display, window,
                               GCGraphicsExposures, &gcvalues);
      }
#endif
      XMesaSetFunction( v->display, b->swapgc, GXcopy );
      /*
       * Set fill style and tile pixmap once for all for HPCR stuff
       * (instead of doing it each time in clear_color_HPCR_pixmap())
       * Initialize whole stuff
       * Patch contributed by Jacques Leroy March 8, 1998.
       */
      if (v->hpcr_clear_flag && b->backxrb && b->backxrb->pixmap) {
         int i;
         for (i = 0; i < 16; i++) {
            XMesaPutPixel(v->hpcr_clear_ximage, i, 0, 0);
            XMesaPutPixel(v->hpcr_clear_ximage, i, 1, 0);
         }
         XMesaPutImage(b->display, (XMesaDrawable) v->hpcr_clear_pixmap,
                       b->cleargc, v->hpcr_clear_ximage, 0, 0, 0, 0, 16, 2);
         XMesaSetFillStyle( v->display, b->cleargc, FillTiled);
         XMesaSetTile( v->display, b->cleargc, v->hpcr_clear_pixmap );
      }

      /* Initialize the row buffer XImage for use in write_color_span() */
      data = (char*) MALLOC(MAX_WIDTH*4);
#ifdef XFree86Server
      b->rowimage = XMesaCreateImage(GET_VISUAL_DEPTH(v), MAX_WIDTH, 1, data);
#else
      b->rowimage = XCreateImage( v->display,
                                  v->visinfo->visual,
                                  v->visinfo->depth,
                                  ZPixmap, 0,           /*format, offset*/
                                  data,                 /*data*/
                                  MAX_WIDTH, 1,         /*width, height*/
                                  32,                   /*bitmap_pad*/
                                  0                     /*bytes_per_line*/ );
#endif
      if (!b->rowimage)
         return GL_FALSE;
   }

   return GL_TRUE;
}



/*
 * Convert an RGBA color to a pixel value.
 */
unsigned long
xmesa_color_to_pixel(GLcontext *ctx,
                     GLubyte r, GLubyte g, GLubyte b, GLubyte a,
                     GLuint pixelFormat)
{
   XMesaContext xmesa = XMESA_CONTEXT(ctx);
   switch (pixelFormat) {
      case PF_Index:
         return 0;
      case PF_Truecolor:
         {
            unsigned long p;
            PACK_TRUECOLOR( p, r, g, b );
            return p;
         }
      case PF_8A8B8G8R:
         return PACK_8A8B8G8R( r, g, b, a );
      case PF_8A8R8G8B:
         return PACK_8A8R8G8B( r, g, b, a );
      case PF_8R8G8B:
         /* fall through */
      case PF_8R8G8B24:
         return PACK_8R8G8B( r, g, b );
      case PF_5R6G5B:
         return PACK_5R6G5B( r, g, b );
      case PF_Dither:
         {
            DITHER_SETUP;
            return DITHER( 1, 0, r, g, b );
         }
      case PF_1Bit:
         /* 382 = (3*255)/2 */
         return ((r+g+b) > 382) ^ xmesa->xm_visual->bitFlip;
      case PF_HPCR:
         return DITHER_HPCR(1, 1, r, g, b);
      case PF_Lookup:
         {
            LOOKUP_SETUP;
            return LOOKUP( r, g, b );
         }
      case PF_Grayscale:
         return GRAY_RGB( r, g, b );