Andrew Korson: Created page with "The '''reposition''' command changes the position of a screen object currently drawn on the screen by an amount relative to its current position. == Syntax == reposition(s..."

2019-04-19T21:44:59Z

Created page with "The '''reposition''' command changes the position of a screen object currently drawn on the screen by an amount relative to its current position. == Syntax == reposition(s..."

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The '''reposition''' command changes the position of a screen object currently drawn on the screen by an amount relative to its current position.

== Syntax ==

reposition([[screen object|obj]] oA, [[variable|var]] vDX, [[variable|var]] vDY);

== Remarks ==

The position of [[screen object]] '''oA''' is changed to (X + '''vDX''', Y + '''vDY''') where X and Y are its current coordinates. The values of '''vDX''' and '''vDY''' are treated as 8 bit signed numbers (values >= 128 are negative numbers, i.e. 255 = -1, 254 = -2, etc.) Mathematically this is represented as <code>delta = value - 256</code>.

The new location is validated using the [[shuffle]] function.

The [[WinAGI]] compiler allows negative numbers to be assigned to [[variable|variables]] to facilitate use of the '''reposition''' command. The negative number is automatically converted to the correct unsigned 8-bit value. Other AGI compilers may not support this feature.

The '''reposition''' command erases the [[screen object]] from its old location before redrawing it in its new location.

This command can be executed on a [[screen object]] that has been [[animate.obj|initialized]] but not yet [[draw|drawn]]. In this case it will reposition the object without redrawing it.

Use the '''[[reposition.to]]''' and '''[[reposition.to.v]]''' commands to change an object's position using absolute coordinates.

== Possible Errors ==

AGI does not check that object number '''oA''' is a valid [[screen object]]. If it is not, this command will overwrite other data on the [[memory heap]], which may cause unexpected results, including possibly [[crashing AGI]].

== Example ==

<div class="CodeBlockHeader">Code:</div>
<syntaxhighlight lang="agi">
[ move an object down 32 pixels, over 8 pixels
v255 = 8;
v201 = 0;
v201 = v201 - v255; [ convert to negative value
v255 = 32;
v202 = 0;
v202 = v202 - v255; [ convert to negative value
reposition(o4, v201, v202); [ make the move

[ in WinAGI you can do this:
v201 = -8;
v202 = -32;
reposition(o4, v201, v202);
</syntaxhighlight>

== Technical Information ==

{| border="1" cellpadding="2"
| style="background-color: #efefef" width="200" | '''Required Interpreter Version:'''
| width="175" | Available in all AGI versions.
|-
| style="background-color: #efefef" | '''Byte-Code Value:'''
| 40 (0x28 hex)
|}

== See Also ==

'''[[position]]'''<br />
'''[[position.v]]'''<br />
'''[[reposition.to]]'''<br />
'''[[reposition.to.v]]'''<br />
[[Category:Commands]]<br />

Reposition - Revision history

Andrew Korson: Created page with "The '''reposition''' command changes the position of a screen object currently drawn on the screen by an amount relative to its current position. == Syntax == reposition(s..."