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ERP's picture

No OpenTK equivalent to Glu.PickMatrix()

Posted Friday, 6 May, 2011 - 16:14 by ERP
Project:The Open Toolkit library
Version:all versions
Component:Code
Category:feature request
Priority:normal
Assigned:Unassigned
Status:open
Description

Library reports that Glu.XXX functions are deprecated and we should use the OpenTK.XXX equivalents.
There is no OpenTK.XXX equivalent for Glu.PickMatrix.


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the Fiddler's picture

#1

Posted Friday, 6 May, 2011 - 16:57 by the Fiddler

Glu.PickMatrix() modifies the matrix stack, which means it cannot be added to OpenTK as-is (the math library cannot use GL calls directly).

Fortunately, the source code for this function is very simple:

// Translated to OpenTK
public void PickMatrix(double x, double y, double deltax, double deltay, int[] viewport)
{
    if (deltax <= 0 || deltay <= 0) { 
	return;
    }
 
    /* Translate and scale the picked region to the entire window */
    GL.Translate((viewport[2] - 2 * (x - viewport[0])) / deltax,
	    (viewport[3] - 2 * (y - viewport[1])) / deltay, 0);
    GL.Scale(viewport[2] / deltax, viewport[3] / deltay, 1.0);
}
ERP's picture

#2

Posted Friday, 6 May, 2011 - 23:05 by ERP

I don't have a problem with it not being as-is.
I was assuming it would be implemented along the lines of the existing OpenTK.LookAt/OpenTK.Perspective.