From e0d3354a77c94d45ec0f2b0a012ab8171c0cd2e1 Mon Sep 17 00:00:00 2001
From: Matthew Gordon <matthew@gordon.earth>
Date: Fri, 4 Sep 2020 22:01:40 -0400
Subject: [PATCH] Add ColourXyz::from_photon()

---
 src/colour/colour_xyz.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/colour/colour_xyz.rs b/src/colour/colour_xyz.rs
index b6ded3d..50829c8 100644
--- a/src/colour/colour_xyz.rs
+++ b/src/colour/colour_xyz.rs
@@ -1,6 +1,6 @@
 use crate::math::{Mat3, Vec3};
 
-use super::ColourRgbF;
+use super::{ColourRgbF, Photon};
 
 /// A CIE XYZ Colour Value
 #[derive(Clone, Debug, Default, PartialEq)]
@@ -28,6 +28,12 @@ impl ColourXyz {
         ColourXyz { values }
     }
 
+    pub fn from_photon(photon: &Photon) -> ColourXyz {
+        let mut result = Self::for_wavelength(photon.wavelength);
+        result.values *= photon.intensity;
+        result
+    }
+
     pub fn x(&self) -> f64 {
         self.values.x()
     }