Specifying a point of origin

Richard Gaskin ambassador at fourthworld.com
Tue Oct 22 12:01:37 EDT 2002


Roger.E.Eller at sealedair.com wrote:

> 
> I am building a Rev app that reads CAD-like files (text based), and uses X
> Y coordinates to visualize the drawing on screen.
> This is being done by creating graphic lines, polygons, ovals, and
> rectangles. It works perfectly except for one problem. Because the point of
> origin (0,0) is at the top-left for Rev, and the CAD system uses
> bottom-left, the drawings are flipped (mirrored) vertically on screen.
> 
> Is there a way to set the point of origin to a specific corner of the
> screen before creating the graphics? Or is there some kind of  workaround?

This is a common challenge with computer graphics, as pretty much all screen
coordunate systems have 0,0 in the upper left of the content region of a
window.

Probably the simplest approch would be to subtract the y coordinate from the
height of the stack for each point -- could be done in a loop fairly
quickly.

-- 
 Richard Gaskin 
 Fourth World Media Corporation
 Custom Software and Web Development for All Major Platforms
 Developer of WebMerge 2.0: Publish any database on any site
 ___________________________________________________________
 Ambassador at FourthWorld.com       http://www.FourthWorld.com
 Tel: 323-225-3717                       AIM: FourthWorldInc




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