Yatopia/patches/api/0011-Optimize-Bukkit-s-MapPalette.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: epserv <admin@epserv.ru>
Date: Wed, 2 Dec 2020 19:31:20 +0200
Subject: [PATCH] Optimise Bukkit's MapPalette


diff --git a/src/main/java/org/bukkit/map/MapPalette.java b/src/main/java/org/bukkit/map/MapPalette.java
index 95fe3f4d081053a6cf484e4ef07b474f2dc2ab02..bb8a189d9323ca9d487a60feaa47a9b88c4fa9e5 100644
--- a/src/main/java/org/bukkit/map/MapPalette.java
+++ b/src/main/java/org/bukkit/map/MapPalette.java
@@ -23,6 +23,8 @@ public final class MapPalette {
     }

     private static double getDistance(@NotNull Color c1, @NotNull Color c2) {
+        // Yatopia start - faster method
+        /*
         double rmean = (c1.getRed() + c2.getRed()) / 2.0;
         double r = c1.getRed() - c2.getRed();
         double g = c1.getGreen() - c2.getGreen();
@@ -31,6 +33,16 @@ public final class MapPalette {
         double weightG = 4.0;
         double weightB = 2 + (255 - rmean) / 256.0;
         return weightR * r * r + weightG * g * g + weightB * b * b;
+         */
+        if (c1.getRGB() == c2.getRGB()) {
+            return 0.0;
+        }
+        double r = c1.getRed() - c2.getRed(),
+                g = c1.getGreen() - c2.getGreen(),
+                b = c1.getBlue() - c2.getBlue(),
+                x = (c1.getRed() + c2.getRed()) / 512d + 2d;
+        return x * r * r + 4 * g * g + (4.99609375d - x) * b * b;
+        // Yatopia end
     }

     @NotNull
@@ -96,6 +108,17 @@ public final class MapPalette {
         c(14, 127, 93), c(17, 155, 114), c(20, 180, 133), c(10, 95, 70)
     };

+    // Yatopia start - all colors as rgb integers
+    @NotNull
+    static final int[] rgbColors = new int[colors.length];
+    static {
+        for (int i = 0; i < colors.length; i++) {
+            rgbColors[i] = colors[i].getRGB();
+        }
+        java.util.Arrays.sort(rgbColors);
+    }
+    // Yatopia end
+
     // Interface
     /**
      * @deprecated Magic value
@@ -235,19 +258,43 @@ public final class MapPalette {
     public static byte matchColor(@NotNull Color color) {
         if (color.getAlpha() < 128) return 0;

+        // Yatopia start - binary search first
+        int binaryIndex = java.util.Arrays.binarySearch(rgbColors, color.getRGB());
+        if (binaryIndex != -1) {
+            return (byte) (binaryIndex < 128 ? binaryIndex : binaryIndex - 256);
+        }
+        // Yatopia end
+
         int index = 0;
         double best = -1;

         for (int i = 4; i < colors.length; i++) {
             double distance = getDistance(color, colors[i]);
+            // Yatopia start - optimise this
+            /*
             if (distance < best || best == -1) {
                 best = distance;
                 index = i;
             }
+             */
+            if (i == 4) {
+                if (distance == 0) {
+                    return (byte) i;
+                }
+                best = distance;
+                index = i;
+            } else if (distance < best) {
+                if (distance == 0) {
+                    return (byte) i;
+                }
+                best = distance;
+                index = i;
+            }
+            // Yatopia end
         }

         // Minecraft has 143 colors, some of which have negative byte representations
-        return (byte) (index < 128 ? index : -129 + (index - 127));
+        return (byte) (index < 128 ? index : index - 256); // Yatopia
     }
 
     /**