Implement point/vector constructors.

rtchallenge/src/tuples.rs

@@ -1,3 +1,4 @@
+#[derive(Debug, PartialEq)]
 struct Tuple {
     x: f32,
     y: f32,
@@ -15,15 +16,23 @@ impl Tuple {
     }
 }
 
+fn point(x: f32, y: f32, z: f32) -> Tuple {
+    tuple(x, y, z, 1.0)
+}
+
+fn vector(x: f32, y: f32, z: f32) -> Tuple {
+    tuple(x, y, z, 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;
+    use super::{point, tuple, vector};
     #[test]
-    fn point() {
+    fn is_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);
@@ -34,7 +43,7 @@ mod tests {
         assert!(!a.is_vector());
     }
     #[test]
-    fn vector() {
+    fn is_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);
@@ -44,4 +53,12 @@ mod tests {
         assert!(!a.is_point());
         assert!(a.is_vector());
     }
+    #[test]
+    fn point_tuple() {
+        assert_eq!(point(4., -4., 3.), tuple(4., -4., 3., 1.))
+    }
+    #[test]
+    fn vector_tuple() {
+        assert_eq!(vector(4., -4., 3.), tuple(4., -4., 3., 0.))
+    }
 }