Chapter 13

1 files changed, 14 insertions, 1 deletions

diff --git a/vec3.go b/vec3.go
index f590625..068ef6c 100644
--- a/vec3.go
+++ b/vec3.go
@@ -82,7 +82,7 @@ func RandomVec3OnUnitSphere() (v Vec3) {
   i := Interval{-1, 1}
 
   for true {
-    v = i.RandomVec3()
+    v = Vec3{i.Sample(), i.Sample(), i.Sample()}; 
     if v.MagSqr() < 1 {
       v = v.Unit();
       return;
@@ -92,6 +92,19 @@ func RandomVec3OnUnitSphere() (v Vec3) {
   return;
 }
 
+func RandomVec3OnUnitDisk() (v Vec3) {
+  i := Interval{-1, 1}
+
+  for true {
+    v = Vec3{i.Sample(), i.Sample(), 0}; 
+    if v.MagSqr() < 1 {
+      return;
+    }
+  }
+
+  return;
+}
+
 func (v Vec3) Reflect(n Vec3) Vec3 {
   return v.Sub(SplatVec3(2 * v.Dot(n)).Mul(n));
 }