entity effect magic

Fixes ViaVersion#3927

Author: kennytv

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/BlockItemPacketRewriter1_20_5.java

@@ -225,18 +225,32 @@ public void registerPackets() {
             wrapper.passthrough(Types.DOUBLE); // X
             wrapper.passthrough(Types.DOUBLE); // Y
             wrapper.passthrough(Types.DOUBLE); // Z
-            wrapper.passthrough(Types.FLOAT); // Offset X
-            wrapper.passthrough(Types.FLOAT); // Offset Y
-            wrapper.passthrough(Types.FLOAT); // Offset Z
+            final float offX = wrapper.passthrough(Types.FLOAT);
+            final float offY = wrapper.passthrough(Types.FLOAT);
+            final float offZ = wrapper.passthrough(Types.FLOAT);
             final float data = wrapper.passthrough(Types.FLOAT);
-            wrapper.passthrough(Types.INT); // Particle Count
+            final int count = wrapper.passthrough(Types.INT);
 
             // Read data and add it to Particle
             final ParticleMappings mappings = protocol.getMappingData().getParticleMappings();
             final int mappedId = mappings.getNewId(particleId);
             final Particle particle = new Particle(mappedId);
             if (mappedId == mappings.mappedId("entity_effect")) {
-                particle.add(Types.INT, data != 0 ? ThreadLocalRandom.current().nextInt() : 0); // rgb
+                final int color;
+                if (data == 0) {
+                    // Black
+                    color = 0;
+                } else if (count != 0) {
+                    // Randomized color
+                    color = ThreadLocalRandom.current().nextInt();
+                } else {
+                    // From offset
+                    final int red = Math.round(offX * 255);
+                    final int green = Math.round(offY * 255);
+                    final int blue = Math.round(offZ * 255);
+                    color = (red << 16) | (green << 8) | blue;
+                }
+                particle.add(Types.INT, EntityPacketRewriter1_20_5.withAlpha(color));
             } else if (particleId == mappings.id("dust_color_transition")) {
                 for (int i = 0; i < 7; i++) {
                     particle.add(Types.FLOAT, wrapper.read(Types.FLOAT));

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_3to1_20_5/rewriter/EntityPacketRewriter1_20_5.java

@@ -387,7 +387,7 @@ private void writeAttribute(final PacketWrapper wrapper, final String attributeI
         }
     }
 
-    private int withAlpha(final int rgb) {
+    static int withAlpha(final int rgb) {
         return 255 << 24 | rgb & 0xffffff;
     }
 

common/src/main/java/com/viaversion/viaversion/protocols/v1_20_5to1_21/storage/EfficiencyAttributeStorage.java

@@ -27,10 +27,10 @@
 
 public final class EfficiencyAttributeStorage implements StorableObject {
 
-    public static final EnchantAttributeModifier EFFICIENCY = new EnchantAttributeModifier("minecraft:enchantment.efficiency/mainhand", 19, 0, level -> (level * level) + 1);
-    public static final EnchantAttributeModifier SOUL_SPEED = new EnchantAttributeModifier("minecraft:enchantment.soul_speed", 21, 0.1, level -> 0.04D + ((level - 1) * 0.01D));
-    public static final EnchantAttributeModifier SWIFT_SNEAK = new EnchantAttributeModifier("minecraft:enchantment.swift_sneak", 25, 0.3, level -> level * 0.15D);
-    public static final EnchantAttributeModifier DEPTH_STRIDER = new EnchantAttributeModifier("minecraft:enchantment.depth_strider", 30, 0, level -> level / 3D);
+    private static final EnchantAttributeModifier EFFICIENCY = new EnchantAttributeModifier("minecraft:enchantment.efficiency/mainhand", 19, 0, level -> (level * level) + 1);
+    private static final EnchantAttributeModifier SOUL_SPEED = new EnchantAttributeModifier("minecraft:enchantment.soul_speed", 21, 0.1, level -> 0.04D + ((level - 1) * 0.01D));
+    private static final EnchantAttributeModifier SWIFT_SNEAK = new EnchantAttributeModifier("minecraft:enchantment.swift_sneak", 25, 0.3, level -> level * 0.15D);
+    private static final EnchantAttributeModifier DEPTH_STRIDER = new EnchantAttributeModifier("minecraft:enchantment.depth_strider", 30, 0, level -> level / 3D);
     private static final ActiveEnchants DEFAULT = new ActiveEnchants(-1,
         new ActiveEnchant(EFFICIENCY, 0),
         new ActiveEnchant(SOUL_SPEED, 0),
@@ -115,18 +115,7 @@ public record ActiveEnchants(int entityId, ActiveEnchant efficiency, ActiveEncha
     public record ActiveEnchant(EnchantAttributeModifier modifier, int level) {
     }
 
-    public static final class EnchantAttributeModifier { // Private constructor, equals by reference
-        private final String key;
-        private final int attributeId;
-        private final double baseValue;
-        private final LevelToModifier modifierFunction;
-
-        private EnchantAttributeModifier(final String key, final int attributeId, final double baseValue, final LevelToModifier modifierFunction) {
-            this.key = key;
-            this.attributeId = attributeId;
-            this.baseValue = baseValue;
-            this.modifierFunction = modifierFunction;
-        }
+    public record EnchantAttributeModifier(String key, int attributeId, double baseValue, LevelToModifier modifierFunction) {
     }
 
     @FunctionalInterface