/apps/demos/scenery: culling

include/twn_vec.h

@@ -29,10 +29,20 @@ static inline Vec2 vec2_scale(Vec2 a, float s) {
     return (Vec2) { a.x * s, a.y * s };
 }
 
+static inline float vec2_dot(Vec2 a, Vec2 b) {
+    return a.x * b.x + a.y * b.y;
+}
+
 static inline float vec2_length(Vec2 a) {
     return sqrtf(a.x * a.x + a.y * a.y);
 }
 
+static inline Vec2 vec2_norm(Vec2 a) {
+    const float n = sqrtf(vec2_dot(a, a));
+    /* TODO: do we need truncating over epsilon as cglm does? */
+    return vec2_scale(a, 1.0f / n);
+}
+
 static inline Vec3 vec3_add(Vec3 a, Vec3 b) {
     return (Vec3) { a.x + b.x, a.y + b.y, a.z + b.z };
 }