feat(engine): add basic flat lighting

1 files changed, 17 insertions, 0 deletions

diff --git a/engine/src/math.rs b/engine/src/math.rs
new file mode 100644
index 0000000..bda3b59
--- /dev/null
+++ b/engine/src/math.rs
@@ -0,0 +1,17 @@
+//! Miscellaneous math functions.
+
+use crate::vector::Vec3;
+
+/// Calculates the surface normal of a triangle.
+#[must_use]
+pub fn calc_triangle_surface_normal(
+    egde_a: &Vec3<f32>,
+    edge_b: &Vec3<f32>,
+    edge_c: &Vec3<f32>,
+) -> Vec3<f32>
+{
+    let v1 = edge_b.clone() - egde_a.clone();
+    let v2 = edge_c.clone() - egde_a.clone();
+
+    v1.cross(&v2)
+}