1// module `package::util` (which shares its name with `fn util` declared in the
2// root module: modules and declarations live in separate namespaces).
3
4// importing from one's own submodule requires a package-anchored path.
5import package::util::ops::double;
6
7// module attribute: marks this module as designed for wildcard imports.
8// TODO: wildcards
9// @!wildcardable;
10
11// package-visible (default): usable from any module of this package,
12// but not across package boundaries and not re-exportable.
13const EPSILON: f32 = 1e-5;
14
15// private: visible only within this module.
16private const INTERNAL_SCALE: f32 = 2.0;
17
18// public: visible from any package, and re-exportable (see prelude.wesl).
19public fn dot2(a: vec2f, b: vec2f) -> f32 {
20    return a.x * b.x + a.y * b.y;
21}
22
23public fn cross2(a: vec2f, b: vec2f) -> f32 {
24    return a.x * b.y - a.y * b.x;
25}
26
27// a public function may refer to less-visible items (EPSILON, INTERNAL_SCALE).
28public fn norm2(a: vec2f) -> f32 {
29    return sqrt(max(dot2(a, a), EPSILON)) * INTERNAL_SCALE / double(1.0);
30}