1 files changed, 28 insertions, 0 deletions

diff --git a/src/bitmap.rs b/src/bitmap.rs
index 41af745..dc66d73 100644
--- a/src/bitmap.rs
+++ b/src/bitmap.rs
@@ -76,6 +76,14 @@ pub enum Axis {
     Y,
 }
 
+#[derive(Debug, Copy, Clone)]
+pub enum Quadrant {
+    I,
+    II,
+    III,
+    IV,
+}
+
 impl MapPoint {
     #[inline]
     pub fn scale(self, c: u32) -> MapPoint {
@@ -98,6 +106,17 @@ impl MapPoint {
     pub fn reflect(self, around: MapPoint) -> MapPoint {
         around.scale(2) - self
     }
+
+    #[inline]
+    pub fn quadrant(self, origin: MapPoint) -> Quadrant {
+        match (self, origin) {
+            _ if self.x >= origin.x && self.y >= origin.y => Quadrant::I,
+            _ if self.x < origin.x && self.y >= origin.y => Quadrant::II,
+            _ if self.x < origin.x && self.y < origin.y => Quadrant::III,
+            _ if self.x >= origin.x && self.y < origin.y => Quadrant::IV,
+            _ => unreachable!("unexpected quadrant!"),
+        }
+    }
 }
 
 impl<T> Pixmap<T>
@@ -278,3 +297,12 @@ pub fn mirror_figure(figure: &[MapPoint], line: u32, axis: Axis) -> Vec<MapPoint
 pub fn reflect_figure(figure: &[MapPoint], around: MapPoint) -> Vec<MapPoint> {
     figure.iter().map(|pt| pt.reflect(around)).collect()
 }
+
+pub fn positive_angle_with_x(start: MapPoint, end: MapPoint) -> u32 {
+    if end.x == start.x {
+        return 90;
+    }
+    let numer = (end.y as f64 - start.y as f64).abs();
+    let denum = (end.x as f64 - start.x as f64).abs();
+    (numer / denum).atan().to_degrees() as u32
+}