Hello there,
with this problem I asked lots of people with no success so far.
My hope is that the people at the official opengl forums are able to help me out. So here’s my question/problem:
I’m using code which tries to work like Glu.Project() since OpenTK doesn’t support Glu.
Vector4 pos = new Vector4(s.Position.X, 0.0f, s.Position.Y, 1.0f);
Matrix4 mov = new Matrix4();
Matrix4 prj = new Matrix4();
Matrix4 mpj = new Matrix4();
float[] vp = new float[4];
GL.GetFloat(GetPName.ModelviewMatrix, out mov);
GL.GetFloat(GetPName.ProjectionMatrix, out prj);
GL.GetFloat(GetPName.Viewport, vp);
Matrix4.Mult(ref prj, ref mov, out mpj);
Vector4.Transform(ref pos, ref mpj, out pos);
// Final mathematics as described in OpenGL 2.1 Glu specs
s.set2DPos(new Vector2f( (vp[0] + (vp[2] * (pos.X + 1) / 2.0f)),
(vp[1] + (vp[3] * (pos.Y + 1) / 2.0f)) ));
// Final mathematics as described in OpenGL 3 Vector specs
s.set2DPos(new Vector2f( (view[2] / 2 * pos.X + view[0]),
(view[3] / 2 * pos.X + view[1]) ));
// Neither of them work, but in relation OpenGL 3 vector specs work better.
s is a class which primary exists as a model in 3D space at s.Position.
But the values I’m getting from this are astronomically far beyond the window boundaries.
The ModelView matrix from a breakpoint:
{(1, 0, 0, 0)
(0, 0.7071068, 0.7071068, 0)
(0, -0.7071068, 0.7071068, 0)
(0, -141.4214, -141.4214, 1)}
The Projection matrix from a breakpoint:
{(1.931371, 0, 0, 0)
(0, 2.414213, 0, 0)
(0, 0, -1.0002, -1)
(0, 0, -2.0002, 0)}
Am I doing something wrong or did I get something wrong? Am I missing something?
( see previous suggestions at http://stackoverflow.com/questions/4316330/gl-project-doesnt-work-properly )