Lingo Dictionary > A-C > constraint |
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constraint
Syntax
sprite(
whichSprite
).constraint
the constraint of sprite
whichSprite
Description
Sprite property; determines whether the registration point of the sprite specified by whichSprite
is constrained to the bounding rectangle of another sprite (1 or TRUE
) or not (0 or FALSE
, default).
The constraint
sprite property is useful for constraining a moveable sprite to the bounding rectangle of another sprite to simulate a track for a slider control or to restrict where on the screen a user can drag an object in a game.
The constraint
sprite property affects moveable sprites and the locH
and locV
sprite properties. The constraint point of a moveable sprite cannot be moved outside the bounding rectangle of the constraining sprite. (The constraint point for a bitmap sprite is the registration point. The constraint point for a shape sprite is its top left corner.) When a sprite has a constraint set, the constraint limits override any locH
and locV
sprite property settings.
This property can be tested and set.
Example
This statement removes a constraint
sprite property:
Dot syntax:
sprite(whichSprite).
constraint =
0
Verbose syntax:
set the constraint of sprite whichSprite
to 0
Example
This statement constrains sprite (i + 1) to the boundary of sprite 14:
sprite(i + 1).constraint = 14
Example
This statement checks whether sprite 3 is constrained and activates the handler showConstraint
if it is: (The operator <>
performs a not-equal-to operation.)
if sprite(3).constraint <> 0 then showConstraint
See also
constrainH()
, constrainV()
, locH
, locV
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