fn screen_cells(
clip_from_view: &Mat4,
perspective: bool,
center: Vec3,
depth: f32,
radius: f32,
dims: [u32; 3],
full: ((u32, u32), (u32, u32)),
) -> Option<((u32, u32), (u32, u32))>Expand description
The x and y cells a light’s sphere covers, as inclusive ranges.
A perspective sphere is bounded by its two tangent lines on each screen axis. Those tangents are asymmetric around the projected center for an off-axis sphere, so a radius around that center can miss its outer edge. An orthographic projection has no such asymmetry, and is simply scaled.