From 45c56bbd850202365751ea019baf5131b2eb9fbe Mon Sep 17 00:00:00 2001
From: mob-sakai <sakai861104@gmail.com>
Date: Wed, 8 Nov 2023 20:24:20 +0900
Subject: [PATCH] feat: support 'Active Apply Color Space' for linear color
 space

---
 Scripts/Editor/UIParticleEditor.cs | 12 ------------
 Scripts/UIParticleRenderer.cs      | 19 +++++++++++++++++++
 Scripts/Utils.cs                   | 19 +++++++++++++++++++
 3 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/Scripts/Editor/UIParticleEditor.cs b/Scripts/Editor/UIParticleEditor.cs
index 9037d05..1695bb1 100644
--- a/Scripts/Editor/UIParticleEditor.cs
+++ b/Scripts/Editor/UIParticleEditor.cs
@@ -332,8 +332,6 @@ namespace Coffee.UIExtensions
                 DestroyUIParticle(current);
             }
 
-            // #203: When using linear color space, the particle colors are not output correctly.
-            // To fix, set 'Apply Active Color Space' in renderer module to false.
             var allPsRenderers = targets.OfType<UIParticle>()
                 .SelectMany(x => x.particles)
                 .Where(x => x)
@@ -341,16 +339,6 @@ namespace Coffee.UIExtensions
                 .ToArray();
             if (0 < allPsRenderers.Length)
             {
-                var so = new SerializedObject(allPsRenderers);
-                var sp = so.FindProperty("m_ApplyActiveColorSpace");
-                label = "When using linear color space, the particle colors are not output correctly.\n" +
-                        "To fix, set 'Apply Active Color Space' in renderer module to false.";
-                if (FixButton(sp.boolValue || sp.hasMultipleDifferentValues, label))
-                {
-                    sp.boolValue = false;
-                    so.ApplyModifiedProperties();
-                }
-
                 // Check to use 'TEXCOORD*.zw' components as custom vertex stream.
                 foreach (var psr in allPsRenderers)
                 {
diff --git a/Scripts/UIParticleRenderer.cs b/Scripts/UIParticleRenderer.cs
index c5406d7..778d3de 100644
--- a/Scripts/UIParticleRenderer.cs
+++ b/Scripts/UIParticleRenderer.cs
@@ -18,6 +18,7 @@ namespace Coffee.UIExtensions
         private static readonly List<Material> s_Materials = new List<Material>(2);
         private static MaterialPropertyBlock s_Mpb;
         private static readonly List<UIParticleRenderer> s_Renderers = new List<UIParticleRenderer>();
+        private static readonly List<Color32> s_Colors = new List<Color32>();
         private static readonly Vector3[] s_Corners = new Vector3[4];
         private Material _currentMaterialForRendering;
         private bool _delay;
@@ -380,6 +381,24 @@ namespace Coffee.UIExtensions
                 bounds.extents = extents;
                 workerMesh.bounds = bounds;
                 _lastBounds = bounds;
+
+                // Convert linear color to gamma color.
+                if (QualitySettings.activeColorSpace == ColorSpace.Linear)
+                {
+                    Profiler.BeginSample("[UIParticleRenderer] Convert Linear to Gamma");
+                    workerMesh.GetColors(s_Colors);
+                    var count_c = s_Colors.Count;
+                    for (var i = 0; i < count_c; i++)
+                    {
+                        var c = s_Colors[i];
+                        c.r = c.r.LinearToGamma();
+                        c.g = c.g.LinearToGamma();
+                        c.b = c.b.LinearToGamma();
+                        s_Colors[i] = c;
+                    }
+                    workerMesh.SetColors(s_Colors);
+                    Profiler.EndSample();
+                }
             }
 
             Profiler.EndSample();
diff --git a/Scripts/Utils.cs b/Scripts/Utils.cs
index 59cf2b1..6700333 100644
--- a/Scripts/Utils.cs
+++ b/Scripts/Utils.cs
@@ -6,6 +6,25 @@ using Object = UnityEngine.Object;
 
 namespace Coffee.UIParticleExtensions
 {
+    public static class Color32Extensions
+    {
+        private static byte[] s_LinearToGammaLut;
+
+        public static byte LinearToGamma(this byte self)
+        {
+            if (s_LinearToGammaLut == null)
+            {
+                s_LinearToGammaLut = new byte[256];
+                for (var i = 0; i < 256; i++)
+                {
+                    s_LinearToGammaLut[i] = (byte)(Mathf.LinearToGammaSpace(i / 255f) * 255f);
+                }
+            }
+
+            return s_LinearToGammaLut[self];
+        }
+    }
+
     public static class Vector3Extensions
     {
         public static Vector3 Inverse(this Vector3 self)