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

[User137]

I'll throw out this kind of suggestion:

          if GetKeyState(VK_LEFT) < 0 then
            begin
              if not Blurp.testForWall(Blurp.X-4,Blurp.Y) then
                begin
                  Blurp.X:=Blurp.X-4;
                  AdSpriteEngine.X:=AdSpriteEngine.X+4;
                end;
            end;
          if GetKeyState(VK_RIGHT) < 0 then
            begin
              if not Blurp.testForWall(Blurp.X+4+Blurp.Image.Width,Blurp.Y) then
                begin
                  Blurp.X:=Blurp.X+4;
                  AdSpriteEngine.X:=AdSpriteEngine.X-4;
                end;
            end;
          if GetKeyState(VK_UP) < 0 then
            begin
              if not Blurp.testForWall(Blurp.X,Blurp.Y-4) then
                begin
                  Blurp.Y:=Blurp.Y-4;
                  AdSpriteEngine.Y:=AdSpriteEngine.Y+4;
                end;
            end;
          if GetKeyState(VK_DOWN) < 0 then
            begin
              if not Blurp.testForWall(Blurp.X,Blurp.Y+4+Blurp.Image.Height) then
                begin
                  Blurp.Y:=Blurp.Y+4;
                  AdSpriteEngine.Y:=AdSpriteEngine.Y-4;
                end;
            end;

function TBlurp.testForWall(pointX,pointY:single):boolean;
var tilenr: integer;
begin
  tilenr:=TileInfo[trunc(pointX) div 64, trunc(pointY) div 64].tilenr;
  case tilenr of
    2: result:=true;
    else result:=false;
  end;
end;