Programmer Guide/Command Reference/EVAL/pgtrans: Difference between revisions

Revision as of 10:11, 20 April 2011

Shift, scale and/or rotate a polygon.

Usage

pgtrans(X, IX {, DX, DY), KX, KY, A})

X

a closed point-list or a polygon-stream defining one or more polygons.

IX

The index of the polygon of X to be tested; 0 <= IX < pgget(X)

DX, DY

shift values for x and y (default=0, no shift)

<x[i] , y[i]> -> <x[i]+DX , y[i]+DY>

KX, KY

scaling factors; both factors must be greater than zero (default=1, no scaling)

A: rotation angle in degree (default=0, no rotation); a scaling factors (default=1); rotate the polygon around the center point

@@ Line 6: / Line 6: @@
 :;<var>IX</var>:The index of the polygon of ''X'' to be tested; 0 <= <var>IX</var> < <code>[[../pgget|pgget]](''X'')</code>
 :;<var>DX, DY</var>: shift values for x and y (default=0, no shift)
-::-> shift the center point <code><XC,YC></code> of polygon ''X<sub>IX</sub>'' to <code><XC+''DX'',YC+''YC''>
+::* shift the center point <code><XC,YC></code> of ''X<sub>IX</sub>''
+:::<code><x[i] , y[i]> -> <x[i]+''DX'' , y[i]+''DY''></code>
 :;<var>KX, KY</var>: scaling factors; both factors must be greater than zero (default=1, no scaling)
+::* scale the distances of corners of ''X<sub>IX</sub>'' to the center point
 :;<var>A</var>: rotation angle in degree (default=0, no rotation); a scaling factors (default=1)
 ::rotate the polygon around the center point