[Use-revolution] Re: Constraining Movement

[Geoff Canyon]

At 10:20 AM -0800 11/27/01, Scott Rossi wrote:
>on mouseMove
>  if not the uAllowDrag of me then exit mouseMove
>  set the loc of me to \
>      min(max(the mouseH,left of img myImg + (width of me/2)),\
>      right of img myImg - (width of me/2)),\
>      min(max(the mouseV,top of img myImg + (height of me/2)),\
>      bottom of img myImg - (height of me/2))
>end mouseMove

Somehow the docs on mouseMove keep fooling people (they fooled me until Kevin pointed this out). mouseMove provides you with two arguments, which are the coordinates of the mouse. Using those is obviously more efficient than using the functions to get them again. So the above could become:

on mouseMove pMouseX,pMouseY
  if not the uAllowDrag of me then exit mouseMove
  set the loc of me to \
      min(max(pMouseX,left of img myImg + (width of me/2)),\
      right of img myImg - (width of me/2)),\
      min(max(pMouseY,top of img myImg + (height of me/2)),\
      bottom of img myImg - (height of me/2))
end mouseMove

Of course, if speed were much of an issue you could also precalculate and store the values used for comparison.

regards,

Geoff