tuple equality

tuples/src/lib.rs

@@ -29,10 +29,18 @@ fn tuple_z(tuple: PointVector) -> f32 {
 fn tuple_is_point(tuple: PointVector) -> bool {
     relative_eq!(1.0, tuple.3)
 }
+
 fn tuple_is_vector(tuple: PointVector) -> bool {
     relative_eq!(0.0, tuple.3)
 }
 
+fn tuple_equals(lhs: PointVector, rhs: PointVector) -> bool {
+    relative_eq!(lhs.0, rhs.0)
+        && relative_eq!(lhs.1, rhs.1)
+        && relative_eq!(lhs.2, rhs.2)
+        && relative_eq!(lhs.3, rhs.3)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -70,4 +78,25 @@ mod tests {
         let vector = vector((4.0, -4.0, 3.0));
         assert_eq!(true, tuple_is_vector(vector));
     }
+
+    #[test]
+    fn tuples_equal() {
+        let lhs = point((1.0, 2.0, 3.0));
+        let rhs = point((1.0, 2.0, 3.0));
+        assert_eq!(true, tuple_equals(lhs, rhs));
+    }
+
+    #[test]
+    fn tuples_relative_equal() {
+        let lhs = point((1.0000001, 2.0, 3.0));
+        let rhs = point((1.0, 2.0, 3.0));
+        assert_eq!(true, tuple_equals(lhs, rhs));
+    }
+
+    #[test]
+    fn tuples_not_equal() {
+        let lhs = point((1.0, 2.0, 3.0));
+        let rhs = vector((1.0, 2.0, 3.0));
+        assert_eq!(false, tuple_equals(lhs, rhs));
+    }
 }