Added color

color/src/lib.rs

@@ -0,0 +1,127 @@
+#[macro_use]
+extern crate approx;
+
+use std::ops;
+
+#[derive(Debug)]
+struct Color {
+    red: f32,
+    green: f32,
+    blue: f32,
+}
+
+impl Color {
+    pub fn new(red: f32, green: f32, blue: f32) -> Color {
+        Color {
+            red,
+            green,
+            blue,
+        }
+    }
+}
+
+impl PartialEq for Color {
+    fn eq(&self, _rhs: &Self) -> bool {
+        relative_eq!(self.red, _rhs.red)
+            && relative_eq!(self.green, _rhs.green)
+            && relative_eq!(self.blue, _rhs.blue)
+    }
+}
+
+impl ops::Add for Color {
+    type Output = Color;
+
+    fn add(self, _rhs: Color) -> Color {
+        Color::new(
+            self.red + _rhs.red,
+            self.green + _rhs.green,
+            self.blue + _rhs.blue,
+            )
+    }
+
+}
+
+impl ops::Mul for Color {
+    type Output = Color;
+    
+    fn mul(self, _rhs: Color) -> Color {
+        Color::new(
+            self.red * _rhs.red,
+            self.green * _rhs.green,
+            self.blue * _rhs.blue,
+        )
+    }
+}
+
+impl ops::Mul<i32> for Color {
+    type Output = Color;
+
+    fn mul(self, _rhs: i32) -> Color {
+        let val = _rhs as f32;
+        Color::new(
+            self.red * val,
+            self.green * val,
+            self.blue * val,
+        )
+    }
+}
+
+impl ops::Sub for Color {
+    type Output = Color;
+
+    fn sub(self, _rhs: Color) -> Color {
+        Color::new(
+            self.red - _rhs.red,
+            self.green - _rhs.green,
+            self.blue - _rhs.blue,
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn color() {
+        let c = Color::new(-0.5, 0.4, 1.7);
+        assert_eq!(-0.5, c.red);
+        assert_eq!(0.4, c.green);
+        assert_eq!(1.7, c.blue);
+    }
+
+    #[test]
+    fn add() {
+        let c1 = Color::new(0.9, 0.6, 0.75);
+        let c2 = Color::new(0.7, 0.1, 0.25);
+        let res = Color::new(1.6, 0.7, 1.0);
+
+        assert_eq!(res, c1 + c2);
+    }
+
+    #[test]
+    fn sub() {
+        let c1 = Color::new(0.9, 0.6, 0.75);
+        let c2 = Color::new(0.7, 0.1, 0.25);
+        let res = Color::new(0.2, 0.5, 0.5);
+
+        assert_eq!(res, c1 - c2);
+    }
+
+    #[test]
+    fn mul_by_scalar() {
+        let c = Color::new(0.9, 0.6, 0.75);
+        let res = Color::new(1.8, 1.2, 1.5);
+
+        assert_eq!(res, c * 2);
+    }
+
+    #[test]
+    fn mul() {
+        let c1 = Color::new(1.0, 0.2, 0.4);
+        let c2 = Color::new(0.9, 1.0, 0.1);
+        let res = Color::new(0.9, 0.2, 0.04);
+
+        assert_eq!(res, c1 * c2);
+    }
+}