Draw pattern for texture with angle

[WojTec]

Hello,

Currently I'm working on halftone and have question.
I want to draw halftone shape texture and then merge it or blend with image to get halftone print. This is easy, all I need I have.

Problem is how to draw pattern (currently I'm using halftone screens generated with Photoshop) with angle? Normal drawing (0 degree) is easy, how draw with angle?

PS: I'm using GR32 for imaging.