Function tex_sample_coords

tools/bloom-reference/src/main.rs:378–388

Shared bilinear coord computation so every texture sampler does the same wrapping and interpolation math.

(tex: &Texture, uv: Vec2)

/// Shared bilinear coord computation so every texture sampler does
/// the same wrapping and interpolation math.
fn tex_sample_coords(tex: &Texture, uv: Vec2) -> (i32, i32, f32, f32) {
    let u = uv.x - uv.x.floor();
    let v = uv.y - uv.y.floor();
    let fx = u * tex.width as f32 - 0.5;
    let fy = v * tex.height as f32 - 0.5;
    let x0 = fx.floor() as i32;
    let y0 = fy.floor() as i32;
    let tx = fx - x0 as f32;
    let ty = fy - y0 as f32;
    (x0, y0, tx, ty)
}

fn srgb_u8_to_linear(c: u8) -> f32 {
    let s = c as f32 / 255.0;