3.5

1 files changed, 44 insertions, 0 deletions

diff --git a/src/main.zig b/src/main.zig
index aa0fa3c..e615e8b 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -421,6 +421,50 @@ fn randomReal(rand: std.rand.Random, min: f64, max: f64) f64 {
     return min + randomReal01(rand) * (max - min);
 }
 
+const Aabb = struct {
+    min: Point3,
+    max: Point3,
+
+    fn hit(aabb: Aabb, r: Ray, tMin: f64, tMax: f64) bool {
+        var tMin_ = tMin;
+        var tMax_ = tMax;
+        {
+            const s0 = (aabb.min.x - r.origin.x) / r.dir.x;
+            const s1 = (aabb.max.x - r.origin.x) / r.dir.x;
+            const t0 = @min(s0, s1);
+            const t1 = @max(s0, s1);
+            tMin_ = @max(t0, tMin_);
+            tMax_ = @min(t1, tMax_);
+            if (tMax_ <= tMin_) {
+                return false;
+            }
+        }
+        {
+            const s0 = (aabb.min.y - r.origin.y) / r.dir.y;
+            const s1 = (aabb.max.y - r.origin.y) / r.dir.y;
+            const t0 = @min(s0, s1);
+            const t1 = @max(s0, s1);
+            tMin_ = @max(t0, tMin_);
+            tMax_ = @min(t1, tMax_);
+            if (tMax_ <= tMin_) {
+                return false;
+            }
+        }
+        {
+            const s0 = (aabb.min.z - r.origin.z) / r.dir.z;
+            const s1 = (aabb.max.z - r.origin.z) / r.dir.z;
+            const t0 = @min(s0, s1);
+            const t1 = @max(s0, s1);
+            tMin_ = @max(t0, tMin_);
+            tMax_ = @min(t1, tMax_);
+            if (tMax_ <= tMin_) {
+                return false;
+            }
+        }
+        return true;
+    }
+};
+
 const Camera = struct {
     origin: Point3,
     horizontal: Vec3,