Posted by elect on Feb 15, 2016; 7:41am
URL: https://forum.jogamp.org/If-I-want-to-construct-complex-geomtry-models-out-of-simple-geometry-how-would-I-do-that-tp4036219p4036230.html

For ortho the coordinates can also be non-normalized, so that you can leave your geometry as it is

If you need your geometry to have exact and precise dimensions, use ortho setting the sides of the box as big as your screen. If you have 600x400, then choose left = -300, right = -300, up= 200 down = -200, near and far plane up to you, say [-100, 100].

A matrix multiplication costs something (probably very small) in terms of performances, but matrices are one of the fundamentals about 3d rendering, so this is not something you can skip

You don't need to calculate it by your own however, you can use the Floatutility class inside jogl or one of the math lib around like joml or mine jglm