Add gradient name colours

Author: PointerRain

src/client/java/golden/scnicknamer/DisplayMapping.java

@@ -3,7 +3,8 @@
 import java.util.UUID;
 import org.jetbrains.annotations.NotNull;
 
-public record DisplayMapping(String mc_name, UUID mc_uuid, String nickname, String colour) {
+public record DisplayMapping(String mc_name, UUID mc_uuid,
+                             String nickname, String colour, String[] colours) {
 
     @Override @NotNull
     public String toString() {

src/client/java/golden/scnicknamer/GradientUtil.java

@@ -0,0 +1,89 @@
+package golden.scnicknamer;
+
+import net.minecraft.text.MutableText;
+import net.minecraft.text.Style;
+import net.minecraft.text.Text;
+
+import java.util.List;
+
+/**
+ * Utility class for applying gradient colors to text.
+ */
+public class GradientUtil {
+
+    /**
+     * Applies a gradient to the given text using the specified colors.
+     * Expects the number of colors to be less than the number of characters in the text.
+     *
+     * @param text   The text to apply the gradient to.
+     * @param colors An array of colors in integer format (0xRRGGBB).
+     * @return A new Text object with the gradient applied.
+     */
+    public static Text applyGradient(Text text, int[] colors) {
+        String str = text.getString();
+        Style style = text.getStyle();
+        int length = str.length();
+
+        if (length < 1 || colors == null || colors.length < 1) {    // No text or no colors
+            return text;
+        }
+        if (length == 1 || colors.length == 1) {    // Single character or single color
+            return Text.literal(str).setStyle(style.withColor(colors[0]));
+        }
+
+        MutableText result = Text.empty();
+        int segments = colors.length - 1;
+
+        for (int i = 0; i < length; i++) {
+            float pos = (float) i / (length - 1);
+            int seg = Math.min((int) (pos * segments), segments - 1);
+            float localRatio = pos * segments - seg;
+
+            int color = interpolateColours(colors[seg], colors[seg + 1], localRatio);
+            result.append(Text.literal(String.valueOf(str.charAt(i))).setStyle(style.withColor(color)));
+        }
+        return result;
+    }
+
+    /**
+     * Applies a gradient to the given text using the specified hex color strings.
+     *
+     * @param text      The text to apply the gradient to.
+     * @param hexColors A list of colors in hex string format.
+     * @return A new Text object with the gradient applied.
+     * @see #applyGradient(Text, int[])
+     */
+    public static Text applyGradient(Text text, List<String> hexColors) {
+        int[] colorInts = hexColors.stream()
+                .mapToInt(c -> Integer.parseInt(c, 16))
+                .toArray();
+
+        return applyGradient(text, colorInts);
+    }
+
+    /**
+     * Helper method to interpolate between two colors.
+     * @param start Start color in 0xRRGGBB format
+     * @param end End color in 0xRRGGBB format
+     * @param ratio Ratio between 0 and 1
+     * @return Interpolated color in 0xRRGGBB format
+     */
+    private static int interpolateColours(int start, int end, float ratio) {
+        int r = interpolate(start >> 16 & 0xFF, end >> 16 & 0xFF, ratio);
+        int g = interpolate(start >> 8 & 0xFF, end >> 8 & 0xFF, ratio);
+        int b = interpolate(start & 0xFF, end & 0xFF, ratio);
+
+        return (r << 16) | (g << 8) | b;
+    }
+
+    /**
+     * Helper method to interpolate between two integer values.
+     * @param start The start value
+     * @param end The end value
+     * @param ratio Ratio between 0 and 1
+     * @return Interpolated integer value
+     */
+    private static int interpolate(int start, int end, float ratio) {
+        return (int) (start + (end - start) * ratio);
+    }
+}

src/client/java/golden/scnicknamer/SCNicknamerClient.java

@@ -15,6 +15,8 @@
 
 import java.util.*;
 
+import static golden.scnicknamer.GradientUtil.applyGradient;
+
 /**
  * Client-side mod initializer for the mod "Spooncraft Name Link".
  */
@@ -66,24 +68,30 @@ static MutableText applyMapping(Text message, DisplayMapping mapping,
 
         MutableText outputMessage = Text.empty();
         message.visit((style, text) -> {
+            if (!text.contains(mapping.mc_name())) {
+                outputMessage.append(Text.literal(text).setStyle(style));
+                return Optional.empty();  // Continue visiting
+            }
+
             String replacedText = text;
             Style replacedStyle = style;
 
             // Apply the mapping
-            if (replacedText.contains(mapping.mc_name())) {
-                // Replace the string
-                if (mapping.nickname() != null && replaceName) {
-                    replacedText = replacedText.replace(mapping.mc_name(), mapping.nickname());
-                }
-                // Apply color if specified
-                if (mapping.colour() != null && replaceColour) {
-                    replacedStyle = replacedStyle.withColor(Integer.parseInt(mapping.colour(), 16));
-                }
+            // Replace the string
+            if (mapping.nickname() != null && replaceName) {
+                replacedText = replacedText.replace(mapping.mc_name(), mapping.nickname());
+            }
+            // Apply color if specified
+            if (mapping.colour() != null && replaceColour) {
+                replacedStyle = replacedStyle.withColor(Integer.parseInt(mapping.colour(), 16));
             }
 
             // Create new MutableText with the display string and style
             MutableText newText = (MutableText) Text.of(replacedText);
             newText.setStyle(replacedStyle);
+            if (mapping.colours() != null && mapping.colours().length > 1 && replaceColour) {
+                newText = (MutableText) applyGradient(newText, List.of(mapping.colours()));
+            }
             outputMessage.append(newText);
 
             return Optional.empty();  // Continue visiting