Fixed tritanopia simulation (#525)

Fixed a typo causing incorrect simulation of tritanopic color vision deficiencies. Also added tests for this corrected behavior
JuliaGraphics · Dec 13, 2022 · dc6438f · dc6438f
1 parent eefe438
commit dc6438f
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diff --git a/src/algorithms.jl b/src/algorithms.jl
@@ -135,7 +135,7 @@ function tritanopic(q::T, p, neutral::LMS) where T <: Color
 
     q = LMS(q.l,
             q.m,
-            (one(p) - p) * q.l + p * (-(a*q.l + b*q.m)/c))
+            (one(p) - p) * q.s + p * (-(a*q.l + b*q.m)/c))
     convert(T, q)
 end
 

diff --git a/test/algorithms.jl b/test/algorithms.jl
@@ -55,4 +55,10 @@ using Test, Colors
     # yellow in LCHab
     @test Colors.find_maximum_chroma(LCHab(94.2, 0, 100)) ≈ 93.749 atol=0.01
     @test Colors.find_maximum_chroma(LCHab(97.6, 0, 105)) ≈ 68.828 atol=0.01
+
+    # Color vision deficiency simulations at p=0
+    rgb = RGB(0.44, 0.26, 0.8)
+    @test protanopic(rgb, 0) .≈ rgb
+    @test deuteranopic(rgb, 0) .≈ rgb
+    @test tritanopic(rgb, 0) .≈ rgb
 end