No problem. Alternatively you can do what I imagine is exactly what GLU did. It's a simple bit of maths to work out the equivalent parameters for glFrustum(). You can check the documentation or do the geometry yourself. Either way I recon this should perform the same function.

`public static void gluPerspective(float fovy, float aspect, float near, float far) {`

float bottom = -near * (float) Math.tan(fovy / 2);

float top = -bottom;

float left = aspect * bottom;

float right = -left;

glFrustum(left, right, bottom, top, near, far);

}

This is probably a simpler method, especially if you're not using JOML already. But using JOML is a step towards not using deprecated features so I would go for my first post.