Re: Drawing polygon

From: Fabian Schmied (REMOVETHISfabianDOTschmied_at_fhs-hagenbergDOTacDOTat)
Date: 05/13/04

Date: Thu, 13 May 2004 15:56:52 +0200

maka3 schrieb:
> Hi,
> What's the best way to draw a polygon with 4 corners in directdraw?
> I only see a DrawBox or DrawRectangle function. I've tried this gdi
> approach but it slows down the app.
> IntPtr dc=surface.GetDc();
> Graphics g=Graphics.FromHdc(dc);
> g.DrawPolygon(...);
> surface.Release(dc);

This is a GDI+ approach. It might be faster to p/invoke the GDI
function Polyline, but it's still GDI and not DirectDraw. You can't use
DirectDraw to efficiently draw lines (although there is a DrawLine
method, but it uses GDI) unless you lock the surface and implement a
Bresenham line drawing algorithm or something yourself (which is
difficult in managed DirectX bacause of Lock bugs).

BTW: You need to dispose of the Graphics object before you release the DC.