Merge pull request #411 from antogilbert/rgbafrom

Implement From for RGBColor and RGBAColor

Author: AaronErhardt

plotters/src/style/color.rs

@@ -76,6 +76,12 @@ impl Color for RGBAColor {
     }
 }
 
+impl From<RGBColor> for RGBAColor {
+    fn from(rgb: RGBColor) -> Self {
+        Self(rgb.0, rgb.1, rgb.2, 1.0)
+    }
+}
+
 /// A color in the given palette
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug, Default)]
 pub struct PaletteColor<P: Palette>(usize, PhantomData<P>);

plotters/src/test.rs

@@ -12,3 +12,11 @@ fn regression_test_issue_267() {
         .draw_line(p1, p2, &RGBColor(0, 0, 0).stroke_width(0))
         .unwrap();
 }
+
+#[test]
+fn from_trait_impl_rgba_color() {
+    let rgb = RGBColor(1, 2, 3);
+    let c = RGBAColor::from(rgb);
+
+    assert_eq!(c.rgb(), rgb.rgb());
+}