From 26a22e0cc7b7cc7a16b6322fd5278a47ade5fcb0 Mon Sep 17 00:00:00 2001
From: Brendan Zabarauskas <bjzaba@yahoo.com.au>
Date: Thu, 29 Nov 2012 11:16:28 +1000
Subject: [PATCH] Implement wrap method

---
 src/angle.rs           |  8 ++++++--
 src/test/test_angle.rs | 14 ++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/angle.rs b/src/angle.rs
index 1640907..3487f61 100644
--- a/src/angle.rs
+++ b/src/angle.rs
@@ -37,7 +37,9 @@ pub impl<T:Copy Num NumCast> Radians<T>: Angle<T> {
     #[inline(always)] pure fn to_radians() -> Radians<T> { self }
     #[inline(always)] pure fn to_degrees() -> Degrees<T> { Degrees(*self * cast(180.0 / pi)) }
     
-    #[inline(always)] pure fn wrap() -> Radians<T> { fail(~"Radians.wrap() not yet implemented") }
+    #[inline(always)] pure fn wrap() -> Radians<T> {
+        self % cast(2.0 * pi)   // TODO: keep in the domain of 0 to two_pi
+    }
 }
     
 pub impl<T:Copy Num> Radians<T>: Add<Radians<T>, Radians<T>> {
@@ -87,7 +89,9 @@ pub impl<T:Copy Num NumCast> Degrees<T>: Angle<T> {
     #[inline(always)] pure fn to_radians() -> Radians<T> { Radians(*self * cast(pi / 180.0)) }
     #[inline(always)] pure fn to_degrees() -> Degrees<T> { self }
     
-    #[inline(always)] pure fn wrap() -> Degrees<T> { fail(~"Degrees.wrap() not yet implemented") }
+    #[inline(always)] pure fn wrap() -> Degrees<T> {
+        self % cast(360)   // TODO: keep in the domain of 0 to 360
+    }
 }
     
 pub impl<T:Copy Num> Degrees<T>: Add<Degrees<T>, Degrees<T>> {
diff --git a/src/test/test_angle.rs b/src/test/test_angle.rs
index 14c5c63..86792de 100644
--- a/src/test/test_angle.rs
+++ b/src/test/test_angle.rs
@@ -18,6 +18,13 @@ fn test_radians() {
     assert *Radians(5.0 * pi).to_radians()      == *Radians(5.0 * pi);
     assert *Radians(-pi).to_radians()           == *Radians(-pi);
     
+    assert *Radians(pi).wrap()                  == *Radians(pi);
+    assert *Radians(3.0 * pi).wrap()            == *Radians(pi);
+    assert *Radians(2.0 * pi).wrap()            == *Radians(0.0);
+    assert *Radians(-pi).wrap()                 == *Radians(-pi);
+    assert *Radians(-3.0 * pi).wrap()           == *Radians(-pi);
+    assert *Radians(-2.0 * pi).wrap()           == *Radians(0.0);
+    
     assert *(Radians(pi) + Radians(pi))         == *Radians(2.0 * pi);
     assert *(Radians(2.0 * pi) - Radians(pi))   == *Radians(pi);
     assert *(Radians(pi) * 2.0)                 == *Radians(2.0 * pi);
@@ -40,6 +47,13 @@ fn test_degrees() {
     assert *Degrees(900.0).to_degrees()         == *Degrees(900.0);
     assert *Degrees(-180.0).to_degrees()        == *Degrees(-180.0);
     
+    assert *Degrees(90.0).wrap()                == *Degrees(90.0);
+    assert *Degrees(450.0).wrap()               == *Degrees(90.0);
+    assert *Degrees(360.0).wrap()               == *Degrees(0.0);
+    assert *Degrees(-90.0).wrap()               == *Degrees(-90.0);
+    assert *Degrees(-450.0).wrap()              == *Degrees(-90.0);
+    assert *Degrees(-360.0).wrap()              == *Degrees(0.0);
+    
     assert *(Degrees(180.0) + Degrees(180.0))   == *Degrees(360.0);
     assert *(Degrees(360.0) - Degrees(180.0))   == *Degrees(180.0);
     assert *(Degrees(360.0) * 2.0)              == *Degrees(720.0);