https://www3.ntu.edu.sg/home/ehchua/programming/opengl/HowTo_OpenGL_C.html http://www.cs.nyu.edu/exact/core/gmp/ http://njoubert.com/teaching/cs184_fa08/section/sec09_camera.pdf http://echelog.com/logs/browse/opengl/1391468400
http://imechanica.org/files/Hildebrand-Abeyaratne.pdf dla niklu str. 7