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View Full Version : how the matrix of glOrtho is derived?



Leonard2012
03-12-2012, 11:06 AM
I am new to OpenGL but have 3D geometry background. I check the refernece of OpenGL function glOrtho at http://msdn.microsoft.com/en-us/library/ms537249(v=vs.85).aspx. The corresponding orthographic projection matrix of glOrtho is given. But I cannot figure out how the matrix is derived. Could someone explain this for me please? Thanks.

Alfonse Reinheart
03-12-2012, 11:34 AM
What do you mean by "how the matrix is derived"?

Leonard2012
03-12-2012, 04:04 PM
Hi, I mean in what steps the matrix is obtained.

overlay
03-12-2012, 06:18 PM
Here is a reference:

http://www.songho.ca/opengl/gl_projectionmatrix.html#ortho

Leonard2012
03-12-2012, 09:15 PM
Thanks, that's what I am looking for.