Projection Matrix

mat4 Projection(float fov, float aspect, float zNear, float zFar) {
	// https://msdn.microsoft.com/en-us/library/windows/desktop/bb205350(v=vs.85).aspx

	float tanHalfFov = tanf(DEG2RAD((fov * 0.5f)));
	float fovY = 1.0f / tanHalfFov; // cot(fov/2)
	float fovX = fovY / aspect; // cot(fov/2) / aspect

	mat4 result; // Creates identity matrix

	result._11 = fovX;
	result._22 = fovY;
	result._33 = zFar / (zFar - zNear); // far / range
	result._34 = 1.0f;
	result._43 = -zNear * result._33; // - near * (far / range)
	result._44 = 0.0f;

	return result;
}