From 495c64249c06d7ffd2d52b74d778ff4c0719991f Mon Sep 17 00:00:00 2001
From: Bill Thiede <git@xinu.tv>
Date: Thu, 24 Jun 2021 10:51:35 -0700
Subject: [PATCH] Implement most basic tuple

---
 rtchallenge/src/lib.rs    |  1 +
 rtchallenge/src/main.rs   |  3 +++
 rtchallenge/src/tuples.rs | 47 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)
 create mode 100644 rtchallenge/src/lib.rs
 create mode 100644 rtchallenge/src/main.rs
 create mode 100644 rtchallenge/src/tuples.rs

diff --git a/rtchallenge/src/lib.rs b/rtchallenge/src/lib.rs
new file mode 100644
index 0000000..921850a
--- /dev/null
+++ b/rtchallenge/src/lib.rs
@@ -0,0 +1 @@
+mod tuples;
diff --git a/rtchallenge/src/main.rs b/rtchallenge/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/rtchallenge/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}
diff --git a/rtchallenge/src/tuples.rs b/rtchallenge/src/tuples.rs
new file mode 100644
index 0000000..58f2540
--- /dev/null
+++ b/rtchallenge/src/tuples.rs
@@ -0,0 +1,47 @@
+struct Tuple {
+    x: f32,
+    y: f32,
+    z: f32,
+    w: f32,
+}
+
+impl Tuple {
+    fn is_point(&self) -> bool {
+        self.w == 1.0
+    }
+
+    fn is_vector(&self) -> bool {
+        self.w == 0.0
+    }
+}
+
+fn tuple(x: f32, y: f32, z: f32, w: f32) -> Tuple {
+    Tuple { x, y, z, w }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::tuple;
+    #[test]
+    fn point() {
+        // A tuple with w = 1 is a point
+        let a = tuple(4.3, -4.2, 3.1, 1.0);
+        assert_eq!(a.x, 4.3);
+        assert_eq!(a.y, -4.2);
+        assert_eq!(a.z, 3.1);
+        assert_eq!(a.w, 1.0);
+        assert!(a.is_point());
+        assert!(!a.is_vector());
+    }
+    #[test]
+    fn vector() {
+        // A tuple with w = 0 is a point
+        let a = tuple(4.3, -4.2, 3.1, 0.0);
+        assert_eq!(a.x, 4.3);
+        assert_eq!(a.y, -4.2);
+        assert_eq!(a.z, 3.1);
+        assert_eq!(a.w, 0.0);
+        assert!(!a.is_point());
+        assert!(a.is_vector());
+    }
+}