/*  %kw # %v    %n    %d    %t #                      */
/*  Version # 2    SPRITES.CPP    16-Dec-93    19:07:16 #    */
/* ************************************************** */
/*    METAGRAPHICS SOFTWARE CORPORATION (c) 1993      */
/*    Demonstrates use of sprite animation            */
/* ************************************************** */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <conio.h>
#include <dos.h>
#include <ctype.h>

#include "metawndo.h"   /* master MetaWINDOW include file */
#include "pcxlab.h"     /* PCX lab include file */


/* special stack size declaration if using Turbo or Borland C++ */
#ifdef      TurboC
extern unsigned _stklen = 14336U;  /* stack size 14K */
#endif

// this sample uses the transparent icon class developed in sample ICON.CPP
// define icon class
#include "icons.hpp"


void FlipDisplay( int page );
void WaitDisplayBusy( int busy );

#define pcxname "icons.pcx"

void main( )
{
   int      i, x,y;
   pcxHead  pcxHeader;        /* buffer for reading the files PCX header */
   palData  RGBInfo[256];     /* buffer for reading the files palette    */

   rect     tmpR;             /* variables for getting the brush image */
   long     imsize;           /* off the screen */
   image    *brush;

   Icon     *brushIcon[2];    /* one icon for each page */

   grafMap  page2Bitmap, *bitmapPage[2];   
   grafPort *thePort;
   int   page;



   /* init the system */
   i = InitGraphics( EGA640x350 );
   if( i != 0 ) {
      printf("MetaWINDOW Initialization error #%d\n", i);
      exit(2);
   }

   /* set up second page bitmap for page flip support */
   i = InitBitmap( EGA640x350, &page2Bitmap );
   SetBitmap( GrafPg1, &page2Bitmap );

   /* keep an array of the bitmap pointers for each page */
   GetPort( &thePort );
   bitmapPage[0] = thePort->portMap;
   bitmapPage[1] = &page2Bitmap;
   

   /* put into graphics mode */
   SetDisplay( GrafPg0 ); 

   /* get a bitmap up on the screen via readpcx file */

   /* Read PCX File Header Information */
   if ( ReadPCXInfo( pcxname, &pcxHeader, RGBInfo ) == False )  {
      SetDisplay( TextPg0 );
      printf("Can't read PCX file!\n");
      StopGraphics();
      exit(1);
   }

   /* set palette, based on palette in PCX file */
   WritePalette( 0, 0, (int) QueryColors(), RGBInfo );

   /* Read PCX File to both pages */
   ReadPCX( pcxname, NULL, NULL );
   MoveTo( 10, 300 ); DrawString( "Page 0" );

   PortBitmap( bitmapPage[1] );
   i = ReadPCX( pcxname, NULL, NULL );
   MoveTo( 70, 300 ); DrawString( "Page 1" );
   if( i == False )  {
      SetDisplay( TextPg0 );
      printf("Can't display this file in current video mode!\n" );
      StopGraphics();
      exit(1);
   }

   /* allocate a buffer to hold the brush image */
   SetRect( &tmpR, 0,0,40,50);
   imsize = ImageSize( &tmpR );
   brush = ( image *) malloc( (size_t) imsize );
   if( brush == NULL ) {
      SetDisplay( TextPg0 );
      printf("Can't allocate brush image\n");
      StopGraphics();
      exit(1);
   }

   /* read the icon from the screen bitmap into an image buffer */
   ReadImage( &tmpR, brush );

   /* make an icon out of the brush image, LtBlue is the transparent color */
   brushIcon[0] = new Icon( brush, LtBlue );

   /* we don't need the source image anymore */
   free( brush );

   /* make a copy of it for the second page */
   brushIcon[1] = new Icon( brushIcon[0] );

   /* lets move this icon accross the screen */
   page = 0;
   while( !kbhit() ) {

      for( y = 0; y < 350; y += 5 ) {

         for( x = 0; x < 640; x += 5 ) {

            /* display page */
            FlipDisplay( GrafPg0 + page );

            /* flip to other page */
            page ^= 1;
            /* draw to page */
            PortBitmap( bitmapPage[page] );

            /* draw the icon */
            brushIcon[page]->Show( x, y );

            if( kbhit() )
               break;
         }

         if( kbhit() )
            break;

      }
   }

   delete brushIcon[0];
   delete brushIcon[1];

   SetDisplay( TextPg0 );
   StopGraphics();
   i = QueryError();
   printf("QueryError=%d/%d\n",i >> 7,i & 127);
   exit(i);

}

/* Flip an EGA or VGA to display the second page.

We don't use SetDisplay() becaue it uses the video cards BIOS ROM to
request a page flip.  BIOS ROMS from different manufacturers exhibit
different behavior.  Some wait for the page to become active before
returning, some don't.  Some take a verrrrry looong time to switch
pages (who knows what goofy things they do). SetDisplay also has to
do some extra stuff to make sure the BIOS does what it's supposed to
(like modify the equipment word in case you were mode mono). 
*/

void FlipDisplay( int page )
{


   switch( page ) {

      case GrafPg0:
         outp( 0x3D4, 0x0C );    // CRTC index 0C, start address high
         outp( 0x3D5, 0 );
         break;

      case GrafPg1:
         outp( 0x3D4, 0x0C );    // CRTC index 0C, start address high
         outp( 0x3D5, 0x80 );
         break;

   }

   // wait for a transition into vertical retrace, this will make sure
   // that our new page is displayed before we start modifying the other
   WaitDisplayBusy( True );
   WaitDisplayBusy( False );


}


/* wait for display to:
 busy = True   be in display period
 busy = False  be in vertical retrace period  
*/
void WaitDisplayBusy( int busy )
{

   int   CRTStatusPort, vsync;

   CRTStatusPort = 0x3DA;  // EGA\VGA color and CGA

   if( busy ) {

      // waiting for vertical retrace bit = 0
      vsync = 1;
      while( vsync ) 
         // read the vertical retrace status bit of the CRT status port
         vsync = inp( CRTStatusPort ) & 8;

   } else {

      // waiting for vertical retrace bit = 1
      vsync = 0;
      while( !vsync ) 
         // read the vertical retrace status bit of the CRT status port
         vsync = inp( CRTStatusPort ) & 8;

   }

}