refactor and simplify rendering logic; remove redundant code and consolidate utility methods

src/main/java/eu/mhsl/minecraft/pixelpics/utils/MapColorPalette.java

@@ -1,5 +1,6 @@
 package eu.mhsl.minecraft.pixelpics.utils;
 
+import eu.mhsl.minecraft.pixelpics.render.util.ColorUtil;
 import org.bukkit.map.MapPalette;
 
 import java.awt.Color;
@@ -80,7 +81,7 @@ public final class MapColorPalette {
     }
 
     private static double[] rgbToLab(int r, int g, int b) {
-        double rl = pivotSrgb(r), gl = pivotSrgb(g), bl = pivotSrgb(b);
+        double rl = ColorUtil.toLinear(r), gl = ColorUtil.toLinear(g), bl = ColorUtil.toLinear(b);
         // sRGB -> XYZ (D65)
         double x = rl * 0.4124 + gl * 0.3576 + bl * 0.1805;
         double y = rl * 0.2126 + gl * 0.7152 + bl * 0.0722;
@@ -91,11 +92,6 @@ public final class MapColorPalette {
         return new double[]{116 * fy - 16, 500 * (fx - fy), 200 * (fy - fz)};
     }
 
-    private static double pivotSrgb(int c) {
-        double v = c / 255.0;
-        return v <= 0.04045 ? v / 12.92 : Math.pow((v + 0.055) / 1.055, 2.4);
-    }
-
     private static double pivotXyz(double t) {
         return t > 0.008856 ? Math.cbrt(t) : (7.787 * t + 16.0 / 116.0);
     }