/*
 * Vis5D system for visualizing five dimensional gridded data sets.
 * Copyright (C) 1990 - 2000 Bill Hibbard, Johan Kellum, Brian Paul,
 * Dave Santek, and Andre Battaiola.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * As a special exception to the terms of the GNU General Public
 * License, you are permitted to link Vis5D with (and distribute the
 * resulting source and executables) the LUI library (copyright by
 * Stellar Computer Inc. and licensed for distribution with Vis5D),
 * the McIDAS library, and/or the NetCDF library, where those
 * libraries are governed by the terms of their own licenses.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "../config.h"

/* anim.c */


/*
 * Stored frame animation.
 */

#include <stdio.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include "globals.h"
#include "graphics.h"

#if HAVE_OPENGL
#  include <GL/gl.h>
#elif HAVE_SGI_GL
#  include <gl/gl.h>
#endif

extern XImage *mesa_read_image( void );
extern void mesa_draw_image( XImage *img );



/*
 * Call this once during initialization.
 */
void init_anim( Display_Context dtx )
{
   int i;

   for (i=0;i<MAXTIMES;i++) {
      dtx->cache[i] = NULL;
   }
   dtx->all_invalid = 1;
}




/*
 * Invalidate all the frames in the cache.  This should be called when
 * the viewpoint changes, the selected graphics changes, or the window
 * size changes.
 */
void invalidate_frames( Display_Context dtx )
{
   int i;

   if (!dtx->all_invalid) {

      for (i=0;i<MAXTIMES;i++) {
         if (dtx->cache[i]) {
            XDestroyImage( dtx->cache[i] );
            dtx->cache[i] = NULL;
         }
      }
      dtx->all_invalid = 1;
   }
}


/*
 * This function is called after a frame has been rendered.  If the
 * cached frame is invalid we'll copy the newly rendered frame into the
 * cache.
 * Input:  timestep - a timestep in [0,NumTimes-1]
 * Return:  1 = the cache was loaded with a new image
 *          0 = the cache was unchanged
 */
int save_frame( Display_Context dtx, int timestep )
{
   if (!dtx->cache[timestep]) {
      printf("saving frame %d\n", timestep );
#ifdef HAVE_XMESAGETBACKBUFFER
      dtx->cache[timestep] = mesa_read_image();
#endif
      dtx->all_invalid = 0;
      return 1;
   }
   else {
      return 0;
   }
}


/*
 * This function returns a frame from the cache and displays it.
 * Input:  timestep - a timestep in [0,NumTimes-1]
 * Return:  1 = there was a cached frame and it's now displayed
 *          0 = there was no cached frame to display, we must render it
 */
int get_frame( Display_Context dtx, int timestep )
{
   if (dtx->cache[timestep]) {
      printf("drawing cached frame %d...\n", timestep );
#ifdef HAVE_XMESAGETBACKBUFFER
      mesa_draw_image( dtx->cache[timestep] );
#endif
      return 1;
   }
   else {
      return 0;
   }
}