# HG changeset patch
# User Tess Snider <this@malkyne.org>
# Date 2021-07-24 10:55:15
# Node ID a1bd6e3474d609f9984bd74e51bf2bdaa59eb870
# Parent  d036e3a473230c5d4e114f2e537829888e759b62

Should now extraplate white reactions if any of the channels didn't clip.

diff --git a/Models/ReactionTest.cs b/Models/ReactionTest.cs
--- a/Models/ReactionTest.cs
+++ b/Models/ReactionTest.cs
@@ -177,13 +177,13 @@ namespace DesertPaintCodex.Models
             Reaction = null;
             BadReaction = null;
             State = TestState.Scanning;
+            bool testing3Way = Requires3Way && BufferIsSelected;
             bool foundLab = await ReactionScannerService.Instance.CaptureReactionAsync(this);
             if (foundLab)
             {
                 ObservedColor = ReactionScannerService.Instance.RecordedColor;
                 if (_observedColor != null)
                 {
-                    // Handle the normal case.
                     Clipped = _observedColor.Red switch
                         {
                             0   => ClipType.RedLow,
@@ -212,6 +212,32 @@ namespace DesertPaintCodex.Models
                     {
                         State = TestState.ClippedResult;
                         BadReaction = CalculateReaction();
+
+                        // SPECIAL CASE:
+                        // Check to see if we've got a white-shift reaction that's partially clipped, where we can
+                        // still extrapolate the reaction, based on the available information.
+                        if (!testing3Way && (BadReaction != null))
+                        {
+                            PaintColor baseColor = _recipe.BaseColor;
+                            if ((BadReaction.Red < baseColor.Red) &&
+                                (BadReaction.Green < baseColor.Green) &&
+                                (BadReaction.Blue < baseColor.Blue))
+                            {
+                                // White-shift down clip.
+                                bool extrapolated               = ExtrapolateWhiteFromOneChannel(_observedColor.Red,   0, BadReaction.Red);
+                                if (!extrapolated) extrapolated = ExtrapolateWhiteFromOneChannel(_observedColor.Green, 0, BadReaction.Green);
+                                if (!extrapolated)                ExtrapolateWhiteFromOneChannel(_observedColor.Blue,  0, BadReaction.Blue);
+                            }
+                            else if ((BadReaction.Red > baseColor.Red) &&
+                                (BadReaction.Green > baseColor.Green) &&
+                                (BadReaction.Blue > baseColor.Blue))
+                            {
+                                // White-shift up clip.
+                                bool extrapolated               = ExtrapolateWhiteFromOneChannel(_observedColor.Red,   255, BadReaction.Red);
+                                if (!extrapolated) extrapolated = ExtrapolateWhiteFromOneChannel(_observedColor.Green, 255, BadReaction.Green);
+                                if (!extrapolated)                ExtrapolateWhiteFromOneChannel(_observedColor.Blue,  255, BadReaction.Blue);
+                            }
+                        }
                     }
                     
                     PlayerProfile? profile = ProfileManager.CurrentProfile;
@@ -225,6 +251,18 @@ namespace DesertPaintCodex.Models
             }
         }
 
+        private bool ExtrapolateWhiteFromOneChannel(int result, int clipBound, int reaction)
+        {
+            if (result == clipBound) return false;
+            
+            Clipped  = ClipType.None;
+            Reaction = new Reaction(reaction, reaction, reaction);
+            BadReaction = null;
+            State    = TestState.GoodResult;
+            return true;
+        }
+
+
         public void CancelScan()
         {
             ReactionScannerService.Instance.CancelScan();