pic rotate help

[shoobyman]

code:

setscreen ("offscreenonly") var angle : int := 0 var velx, vely := 0 var chars : array char of boolean var pic : int pic := Pic.FileNew ("ship.bmp") loop     Input.KeyDown (chars)     View.Update     delay (30)     cls     Pic.Draw (pic , 100, 100, picCopy)     pic := Pic.Rotate (pic, angle, 23, 33)     if chars (KEY_LEFT_ARROW) then         angle := 10     elsif chars (KEY_RIGHT_ARROW) then         angle := -10     else         angle := 0     end if end loop

when i run it, if i press the arrow key (other than the pic looking bad), it gives me an error after a few seconds it gives me this error
"illegal picID number "0" (probable cause picture was not successfully created)"

anyone know how to fix it?

[NikG]

shoobyman wrote:

code:

setscreen ("offscreenonly") var angle : int := 0 var velx, vely := 0 var chars : array char of boolean var pic : int pic := Pic.FileNew ("ship.bmp") loop     Input.KeyDown (chars)     View.Update     delay (30)     cls     Pic.Draw (pic , 100, 100, picCopy)     pic := Pic.Rotate (pic, angle, 23, 33)     if chars (KEY_LEFT_ARROW) then         angle := 10     elsif chars (KEY_RIGHT_ARROW) then         angle := -10     else         angle := 0     end if end loop

Your code is kinda all-over-the-place, and I'm almost positive that's why you're getting the error. Here's a cleaner (and probably less error prone) version:

code:

loop     Input.KeyDown (chars)     if chars (KEY_LEFT_ARROW) then         angle := 10         pic := Pic.Rotate (pic, angle, 23, 33)     elsif chars (KEY_RIGHT_ARROW) then         angle := -10         pic := Pic.Rotate (pic, angle, 23, 33)     else         angle := 0         pic := Pic.Rotate (pic, angle, 23, 33)     end if     Pic.Draw (pic , 100, 100, picCopy)     View.Update     delay (30)     cls end loop

Your order of command was weird. Why would you update an empty screen, delay, clear the screen, then draw the pic, then change the angle??? Also, notice how I made it change the angle only if there is input?

[NikG]

Actually, now I know why you're gettin the error.
It's because of your else clause in the if statement. Remove it!

You shouldn't get the error with my code anymore, but it's not proper.
And it doesn't make sense to keep resetting the angle to 0 if there's no input.

[shoobyman]

thanks, everything works (and I fixed the ungly picture problem)