From 6d7998ad9f0547e316a10a257d71ce3a8e496c99 Mon Sep 17 00:00:00 2001
From: Bill Thiede <git@xinu.tv>
Date: Fri, 5 Aug 2022 18:31:09 -0700
Subject: [PATCH] zigrtiow: fix acne

---
 zigrtiow/src/main.zig | 7 ++++---
 zigrtiow/src/vec.zig  | 9 ++++++---
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/zigrtiow/src/main.zig b/zigrtiow/src/main.zig
index 23a461d..3c794d4 100644
--- a/zigrtiow/src/main.zig
+++ b/zigrtiow/src/main.zig
@@ -15,6 +15,7 @@ const Point3 = vec.Point3;
 const Ray = ray.Ray;
 const Sphere = sphere.Sphere;
 const Vec3 = vec.Vec3;
+const random_unit_vector = vec.random_unit_vector;
 const random_in_unit_sphere = vec.random_in_unit_sphere;
 const info = std.log.info;
 const write_color = color.write_color;
@@ -23,10 +24,10 @@ fn ray_color(r: Ray, world: Hittable, depth: isize) Color {
     // If we've exceeded the ray bounce limit, no more light is gathered.
     if (depth <= 0) return Color.init(0, 0, 0);
 
-    var hit = world.hit(r, 0, std.math.inf(f32));
+    var hit = world.hit(r, 0.0001, std.math.inf(f32));
     if (hit) |rec| {
-        const target = rec.p.add(rec.normal.add(random_in_unit_sphere()));
-        return ray_color(Ray.init(rec.p, target.sub(rec.p)), world, depth - 1);
+        const target = rec.p.add(rec.normal.add(random_unit_vector()));
+        return ray_color(Ray.init(rec.p, target.sub(rec.p)), world, depth - 1).scale(0.5);
     }
     var unit_direction = r.direction().unit();
     const t = 0.5 * (unit_direction.y() + 1);
diff --git a/zigrtiow/src/vec.zig b/zigrtiow/src/vec.zig
index 332c7f4..df190da 100644
--- a/zigrtiow/src/vec.zig
+++ b/zigrtiow/src/vec.zig
@@ -47,9 +47,9 @@ pub const Vec3 = struct {
     /// Return value in unit cube from -1, 1
     pub fn random() Vec3 {
         return Vec3.init(
-            rand.float(f32) * 2 - 0.5,
-            rand.float(f32) * 2 - 0.5,
-            rand.float(f32) * 2 - 0.5,
+            rand.float(f32) * 2 - 1,
+            rand.float(f32) * 2 - 1,
+            rand.float(f32) * 2 - 1,
         );
     }
 };
@@ -61,6 +61,9 @@ pub fn random_in_unit_sphere() Vec3 {
         return p;
     }
 }
+pub fn random_unit_vector() Vec3 {
+    return random_in_unit_sphere().unit();
+}
 
 pub const Color = Vec3;
 pub const Point3 = Vec3;