Path: chuka.playstation.co.uk!news
From: "Derek da Silva" <dasi@eidosnet.co.uk>
Newsgroups: scee.yaroze.beginners
Subject: map-tastic tile question
Date: Thu, 17 Jun 1999 12:19:42 +0100
Organization: PlayStation Net Yaroze (SCEE)
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Hi

I'm looking to make some optimizations to a simple tile based game I'm
working on - specifically the method used to draw the visible part of the
map.

At the moment I just run through my array of tiles and check each one to see
if it should be drawn to the screen...

cell_struct cell[map.numcells];

// scroll map by changing map.scrollx and map.scrolly

void Draw_Map_Graphics(void)
{
 u_long register i;

  for(i=0; i<map.numcells; i++)


    map_sprt.x = cell[i].px + map.scrollx;
    map_sprt.y = cell[i].py + map.scrolly;

    if(clip_sprite(map_sprt.x, map_sprt.y, 16, 16)) // check if tile on
screen
    {
      map_sprt.u = ((cell[i].timindex%8) << 5);
      map_sprt.v = ((cell[i].timindex/8) << 5);
      GsSortFastSprite(&map_sprt, &WorldOT[activebuff], 2);
    }
  }
}

I realise this is very inefficient.  Any tips on how to do this better,
smarter and quicker would be greatly appreciated.

Thanks

Derek