colour from hex

Cargo.toml

@@ -12,5 +12,6 @@ keywords = ["gamedev"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-radix_fmt = "1.0.0"
-loe = "0.2.0"
+data-encoding = "^2.3.1"
+radix_fmt = "^1.0.0"
+loe = "^0.2.0"

src/colour.rs

@@ -6,7 +6,7 @@ pub struct Colour {
 }
 
 impl Colour {
-    pub(crate) fn from(string: &str) -> Result<Colour, crate::Error> {
+    pub fn from(string: &str) -> Result<Colour, crate::Error> {
         let values: Vec<&str> = string.trim_matches(',').split(',').collect();
 
         if values.len() != 3 {
@@ -19,6 +19,13 @@ impl Colour {
 
         Ok(Colour { red, green, blue })
     }
+
+    pub fn from_hex(hex: &str) -> Result<Colour, crate::Error> {
+        let hex = hex.to_lowercase().trim_start_matches('#').to_string();
+        let rgb = data_encoding::HEXLOWER.decode(hex.as_bytes()).unwrap();
+
+        Ok(Colour { red: rgb[0], green: rgb[1], blue: rgb[2], })
+    }
 }
 
 impl ToString for Colour {
@@ -58,4 +65,18 @@ mod test {
     fn colour_extraneous_value() {
         assert!(Colour::from("0,0,0,0").is_err());
     }
+
+    #[test]
+    fn colour_from_hex() {
+        let output = Colour::from_hex("#ffff00").unwrap();
+        let expected = Colour { red: 255, green: 255, blue: 0 };
+        assert_eq!(output, expected);
+    }
+
+    #[test]
+    fn colour_from_hex_upper() {
+        let output = Colour::from_hex("#ABCDEF").unwrap();
+        let expected = Colour { red: 171, green: 205, blue: 239 };
+        assert_eq!(output, expected);
+    }
 }