Questions tagged [fragment-shader]

I am trying to get this shader to run on a really old iDevice, as well as eventually Androids. Even when I reduce the code down to 2 sine functions per fragment the shader runs at about 20fps. I have considered taking a leaf out of the book of old…

In a fragment shader, I need to draw a line at a given value of u. The shader is applied to a planar polygon mesh that's being drawn in the scene with a perspective camera. (It isn't a full-screen textured quad; that would be easy!) The problem is,…