From ffb8f0e8d3530e24a4406ebb44e459bb07cfc56e Mon Sep 17 00:00:00 2001
From: Exter-N <exter-n@exter-n.fr>
Date: Mon, 28 Aug 2023 03:06:18 +0200
Subject: [PATCH] =?UTF-8?q?Material=20editor:=20Allow=20negatives=20again?=
 =?UTF-8?q?=20with=20R=C2=B2G=C2=B2B=C2=B2?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

There seems to be people using it.
---
 .../ModEditWindow.Materials.ColorSet.cs       | 26 ++++++++++++++++---
 .../ModEditWindow.Materials.ConstantEditor.cs |  8 +++---
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/Penumbra/UI/AdvancedWindow/ModEditWindow.Materials.ColorSet.cs b/Penumbra/UI/AdvancedWindow/ModEditWindow.Materials.ColorSet.cs
index 798939ca..daca1098 100644
--- a/Penumbra/UI/AdvancedWindow/ModEditWindow.Materials.ColorSet.cs
+++ b/Penumbra/UI/AdvancedWindow/ModEditWindow.Materials.ColorSet.cs
@@ -483,13 +483,13 @@ public partial class ModEditWindow
     private static bool ColorPicker( string label, string tooltip, Vector3 input, Action< Vector3 > setter, string letter = "" )
     {
         var ret = false;
-        var inputSqrt = Vector3.SquareRoot( input );
+        var inputSqrt = PseudoSqrtRgb( input );
         var tmp = inputSqrt;
         if( ImGui.ColorEdit3( label, ref tmp,
-               ImGuiColorEditFlags.NoInputs | ImGuiColorEditFlags.DisplayRGB | ImGuiColorEditFlags.InputRGB | ImGuiColorEditFlags.NoTooltip )
+               ImGuiColorEditFlags.NoInputs | ImGuiColorEditFlags.DisplayRGB | ImGuiColorEditFlags.InputRGB | ImGuiColorEditFlags.NoTooltip | ImGuiColorEditFlags.HDR )
         && tmp != inputSqrt )
         {
-            setter( tmp * tmp );
+            setter( PseudoSquareRgb( tmp ) );
             ret = true;
         }
 
@@ -505,4 +505,24 @@ public partial class ModEditWindow
 
         return ret;
     }
+
+    // Functions to deal with squared RGB values without making negatives useless.
+
+    private static float PseudoSquareRgb(float x)
+        => x < 0.0f ? -(x * x) : (x * x);
+
+    private static Vector3 PseudoSquareRgb(Vector3 vec)
+        => new(PseudoSquareRgb(vec.X), PseudoSquareRgb(vec.Y), PseudoSquareRgb(vec.Z));
+
+    private static Vector4 PseudoSquareRgb(Vector4 vec)
+        => new(PseudoSquareRgb(vec.X), PseudoSquareRgb(vec.Y), PseudoSquareRgb(vec.Z), vec.W);
+
+    private static float PseudoSqrtRgb(float x)
+        => x < 0.0f ? -MathF.Sqrt(-x) : MathF.Sqrt(x);
+
+    private static Vector3 PseudoSqrtRgb(Vector3 vec)
+        => new(PseudoSqrtRgb(vec.X), PseudoSqrtRgb(vec.Y), PseudoSqrtRgb(vec.Z));
+
+    private static Vector4 PseudoSqrtRgb(Vector4 vec)
+        => new(PseudoSqrtRgb(vec.X), PseudoSqrtRgb(vec.Y), PseudoSqrtRgb(vec.Z), vec.W);
 }
\ No newline at end of file
diff --git a/Penumbra/UI/AdvancedWindow/ModEditWindow.Materials.ConstantEditor.cs b/Penumbra/UI/AdvancedWindow/ModEditWindow.Materials.ConstantEditor.cs
index f7ea317d..8a104145 100644
--- a/Penumbra/UI/AdvancedWindow/ModEditWindow.Materials.ConstantEditor.cs
+++ b/Penumbra/UI/AdvancedWindow/ModEditWindow.Materials.ConstantEditor.cs
@@ -147,11 +147,11 @@ public partial class ModEditWindow
                 ImGui.SetNextItemWidth(editorWidth);
                 var value = new Vector3(values);
                 if (_squaredRgb)
-                    value = Vector3.SquareRoot(value);
+                    value = PseudoSqrtRgb(value);
                 if (ImGui.ColorEdit3("##0", ref value, ImGuiColorEditFlags.Float | (_clamped ? 0 : ImGuiColorEditFlags.HDR)) && !disabled)
                 {
                     if (_squaredRgb)
-                        value *= value;
+                        value = PseudoSquareRgb(value);
                     if (_clamped)
                         value = Vector3.Clamp(value, Vector3.Zero, Vector3.One);
                     value.CopyTo(values);
@@ -165,11 +165,11 @@ public partial class ModEditWindow
                 ImGui.SetNextItemWidth(editorWidth);
                 var value = new Vector4(values);
                 if (_squaredRgb)
-                    value = new Vector4(MathF.Sqrt(value.X), MathF.Sqrt(value.Y), MathF.Sqrt(value.Z), value.W);
+                    value = PseudoSqrtRgb(value);
                 if (ImGui.ColorEdit4("##0", ref value, ImGuiColorEditFlags.Float | ImGuiColorEditFlags.AlphaPreviewHalf | (_clamped ? 0 : ImGuiColorEditFlags.HDR)) && !disabled)
                 {
                     if (_squaredRgb)
-                        value *= new Vector4(value.X, value.Y, value.Z, 1.0f);
+                        value = PseudoSquareRgb(value);
                     if (_clamped)
                         value = Vector4.Clamp(value, Vector4.Zero, Vector4.One);
                     value.CopyTo(values);