const int GRIDWIDTH = 20;const int GRIDHEIGHT= 20;const char TileMap [GRIDWIDTH * GRIDHEIGHT] = { . . . };char GetTile(int width, int height){  //the following line will make sure actualHeight is always < GRIDHEIGHT  // no matter how large height may get. look up "modulus operator"  int actualHeight = height % GRIDHEIGHT;  //locate tile in map  return TileMap[GRIDWIDTH * actualHeight + width];}

Quote:Original post by bzroom
Or you'll have to loop the data when you're accessing the tile map. If the currently requested index is beyond the tile map, it is wrapped around to the begining, so your data will scroll continuously for ever.

For example:

const int GRIDWIDTH = 20;const int GRIDHEIGHT= 20;const char TileMap [GRIDWIDTH * GRIDHEIGHT] = { . . . };char GetTile(int width, int height){  //the following line will make sure actualHeight is always < GRIDHEIGHT  // no matter how large height may get. look up "modulus operator"  int actualHeight = height % GRIDHEIGHT;  //locate tile in map  return TileMap[GRIDWIDTH * actualHeight + width];}

It is probably flashing because once you go past the ends of the buffer, nothing tells it to stop. So then you start accesing invalid parts of memory which will have "random" data values. As your code interprets this it would probably appear to "flicker."

The solution I showed you should fix that, provided that width was passed within bounds, [0, GRIDWIDTH-1].

Quote:Original post by MSW
Are you double buffering and not clearing buffers before useing them?