A very weird problem that delays movement of my red square!

[DanceMacabre]

ok! This is the weirdest thing thats ever happened and I'll try my best to explain it. I want this red square to move fluidly and not all screwed up like. as the square moves, it leave red behind it and thats ok, I want that to happen. but sometimes the red behind the square disappears and the squares movement lags like mad. Please look at the code to see if you can figure it out, cause I can't, let alone explain my problem properly. Thank you so much

code:

var keys : array char of boolean View.Set ("graphics,offscreenonly") var x1, y1 : int := 225 const size : int := 3 y1 := maxy - size cls loop drawback delay(300)     Input.KeyDown (keys)     if keys (KEY_DOWN_ARROW) then         loop             y1 -= 1             Draw.FillBox (x1, y1, x1 + size, y1 + size, brightred)             delay(10)             View.Update             exit when hasch         end loop     end if     if keys (KEY_RIGHT_ARROW) then         loop             x1 += 1             Draw.FillBox (x1, y1, x1 + size, y1 + size, brightred)             delay(10)             View.Update             exit when hasch         end loop     end if     if keys (KEY_LEFT_ARROW) then     %%%         loop             x1 -= 1             Draw.FillBox (x1, y1, x1 + size, y1 + size, brightred)             delay(10)             View.Update             exit when hasch         end loop     end if     if keys (KEY_UP_ARROW) then     %%%         loop             y1 += 1             Draw.FillBox (x1, y1, x1 + size, y1 + size, brightred)             delay(10)             View.Update             exit when hasch         end loop     end if end loop

much appreciated

[Cervantes]

Loops nested within if statements within loops is a pretty hefty structure. What's more, it's entirely unecessary.

Instead, use one variable to store the current direction of the box.

code:

var x, y := 100 var keys : array char of boolean var direction := 'u' const speed := 1 loop     Input.KeyDown (keys)     if keys (KEY_DOWN_ARROW) then         direction := 'd'     elsif keys (KEY_UP_ARROW) then         direction := 'u'     elsif keys (KEY_LEFT_ARROW) then         direction := 'l'     elsif keys (KEY_RIGHT_ARROW) then         direction := 'r'     end if     % I'd use a case construct here, but I don't think I remember the syntax quite right     if direction = 'u' then         y += speed     elsif direction = 'd' then         y -= speed     elsif direction = 'l' then         x -= speed     elsif direction = 'r' then         x += speed     end if     Draw.FillOval (x, y, 5, 5, black)     delay (10) end loop

You could even get rid of that second if structure if you used some trig:

code:

var x, y := 100 var keys : array char of boolean var direction := 90 const speed := 1 loop     Input.KeyDown (keys)     if keys (KEY_DOWN_ARROW) then         direction := 270     elsif keys (KEY_UP_ARROW) then         direction := 90     elsif keys (KEY_LEFT_ARROW) then         direction := 180     elsif keys (KEY_RIGHT_ARROW) then         direction := 0     end if     y += sind (direction) * speed     x += cosd (direction) * speed     Draw.FillOval (x, y, 5, 5, black)     delay (10) end loop

[DanceMacabre]

Thanke me matey. Makes sense.