Collission detection on level ( source Travels doc + some other examples)

[User137]

function TBlurp.testForWall(spriteXpos,spriteYpos:single;spriteWidth,spriteHeight:integer):boolean;
begin
  testForWall := false;
  if not (TileInfo[round(spriteXpos) div 64, round(spriteYpos) div 64].tilenr in [2]) or not
  (TileInfo[(round(spriteXpos)+spriteWidth) div 64, round(spriteYpos) div 64].tilenr in [2]) or not
  (TileInfo[round(spriteXpos)div 64, (round(spriteYpos)+spriteHeight) div 64].tilenr in [2]) or not
  (TileInfo[(round(spriteXpos)+spriteWidth) div 64, (round(spriteYpos)+spriteHeight) div 64].tilenr in [2]) then testForWall :=true;
end;

Test with changing round() to trunc(). There is a difference in how they work, and tiles are usually drawn from their top left corner, not from middle.