Function mat4_mul

native/shared/src/models.rs:527–535

(a: &[[f32; 4]; 4], b: &[[f32; 4]; 4])

}

fn mat4_mul(a: &[[f32; 4]; 4], b: &[[f32; 4]; 4]) -> [[f32; 4]; 4] {
    let mut out = [[0.0f32; 4]; 4];
    for col in 0..4 {
        for row in 0..4 {
            out[col][row] = a[0][row]*b[col][0] + a[1][row]*b[col][1] + a[2][row]*b[col][2] + a[3][row]*b[col][3];
        }
    }
    out
}

/// Walk the scene graph and collect EVERY world-space transform that
/// references each mesh. Unlike `walk_scene_for_mesh_transforms` which