Initial Commit, finished Chapter 6

1 files changed, 26 insertions, 0 deletions

diff --git a/ray.go b/ray.go
new file mode 100644
index 0000000..cd4f6aa
--- /dev/null
+++ b/ray.go
@@ -0,0 +1,26 @@
+package main
+
+import (
+  maths "math"
+)
+
+type Ray struct {
+  Origin Vec3
+  Direction Vec3
+}
+
+func (r Ray) At(t float64) Vec3 {
+  return r.Origin.Add(r.Direction.Mul(Splat(t)));
+}
+
+func (r Ray) Colour(world Hittable) Vec3 {
+  hit := world.Hit(r, Interval{0, maths.Inf(1)})
+  if hit.Valid {
+    return hit.N.Add(Splat(1)).Div(Splat(2));
+  }
+
+  unit_dir := r.Direction.Unit();
+  a := (unit_dir.Y + 1) / 2;
+  return Vec3{0.5, 0.7, 1.0}.Mul(Splat(a)).
+         Add(Splat(1).Mul(Splat(1.0 - a)));
+}