I’m developing a cgm viewer and editor, strictly for 2D CAD use. The problem I’m encountering is drifting towards the right of the primatives along the x axis while the app draws a rubber band zoom rectangle. The text however doesn’t drift. I am using lists. The environment is c# .NET. I do not have a lingering translate of the the matrix that draws the primatives, so I am at a loss as to why I’m experiencing this problem.

Has anyone else experienced this kind of problem and what was done to remedy it?

Maybe you just forgot to load the identity matrix before your matrix operations so that the matrix transform gets accumulated each time the screen is refreshed…


I seem to recall something like that happening once.

As I recall, I was using bilinear interpolation and ping-pong rendering. Since texture coordinates are never exact, I was grabbing a little bit of the black beyond one edge with each render, and that was being propagated forward through the ping-pong process, until eventually my entire texture was black.

call me psychic, but I don’t think that’s this guys problem.

You’re right the identity matrix wasn’t being loaded


Told ya, lindley. Teach you to over-estimate people.