Ponies that cast magic now have horns

src/main/java/com/minelittlepony/unicopia/ability/Ability.java

@@ -28,6 +28,10 @@ public interface Ability<T extends Hit> {
      */
     int getCooldownTime(Pony player);
 
+    default int getColor(Pony player) {
+        return -1;
+    }
+
     /**
      * Called when an ability is about to be triggered. This event occurs on both the client and server so check {@code Pony#isClient} if you need to know which one you're on.
      * <p>

src/main/java/com/minelittlepony/unicopia/ability/AbilityDispatcher.java

@@ -64,6 +64,10 @@ public class AbilityDispatcher implements Tickable, NbtSerialisable {
         return stats.values();
     }
 
+    public Optional<Stat> getActiveStat() {
+        return stats.values().stream().filter(stat -> stat.getFillProgress() > 0).findFirst();
+    }
+
     public Stat getStat(AbilitySlot slot) {
         return stats.computeIfAbsent(slot, Stat::new);
     }
@@ -246,7 +250,7 @@ public class AbilityDispatcher implements Tickable, NbtSerialisable {
             return Optional.empty();
         }
 
-        protected synchronized Optional<Ability<?>> getActiveAbility() {
+        public synchronized Optional<Ability<?>> getActiveAbility() {
             return activeAbility.filter(ability -> {
                 return (!(ability == null || (triggered && warmup == 0 && cooldown == 0)) && player.getCompositeRace().any(ability::canUse));
             });

src/main/java/com/minelittlepony/unicopia/ability/UnicornCastingAbility.java

@@ -80,6 +80,22 @@ public class UnicornCastingAbility implements Ability<Hit> {
         return !spell.getResult().isAccepted() || spell.getValue().isOn(player) ? 2 : 4;
     }
 
+    @Override
+    public int getColor(Pony player) {
+        TypedActionResult<ItemStack> amulet = getAmulet(player);
+        if (amulet.getResult().isAccepted()) {
+            return 0x000000;
+        }
+
+        Hand hand = player.asEntity().isSneaking() ? Hand.OFF_HAND : Hand.MAIN_HAND;
+        TypedActionResult<CustomisedSpellType<?>> newSpell = player.getCharms().getSpellInHand(hand);
+
+        if (newSpell.getResult() != ActionResult.FAIL) {
+            return newSpell.getValue().type().getColor();
+        }
+        return -1;
+    }
+
     @Override
     public void apply(Pony player, Hit data) {
         if (!player.canCast()) {

src/main/java/com/minelittlepony/unicopia/ability/UnicornDispellAbility.java

@@ -7,6 +7,7 @@ import com.minelittlepony.unicopia.InteractionManager;
 import com.minelittlepony.unicopia.Race;
 import com.minelittlepony.unicopia.ability.data.Pos;
 import com.minelittlepony.unicopia.ability.magic.Caster;
+import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.client.render.PlayerPoser.Animation;
 import com.minelittlepony.unicopia.entity.player.Pony;
 import com.minelittlepony.unicopia.particle.MagicParticleEffect;
@@ -36,6 +37,11 @@ public class UnicornDispellAbility implements Ability<Pos> {
         return race.canCast() || race == Race.CHANGELING;
     }
 
+    @Override
+    public int getColor(Pony player) {
+        return SpellType.PORTAL.getColor();
+    }
+
     @Override
     public Identifier getIcon(Pony player, boolean swap) {
         Identifier id = Abilities.REGISTRY.getId(this);

src/main/java/com/minelittlepony/unicopia/ability/UnicornTeleportAbility.java

@@ -5,6 +5,7 @@ import com.minelittlepony.unicopia.USounds;
 import com.minelittlepony.unicopia.ability.data.Hit;
 import com.minelittlepony.unicopia.ability.data.Pos;
 import com.minelittlepony.unicopia.ability.magic.Caster;
+import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.entity.Living;
 import com.minelittlepony.unicopia.entity.player.Pony;
 import com.minelittlepony.unicopia.particle.MagicParticleEffect;
@@ -60,6 +61,11 @@ public class UnicornTeleportAbility implements Ability<Pos> {
         return pos.distanceTo(player) / 10;
     }
 
+    @Override
+    public int getColor(Pony player) {
+        return SpellType.PORTAL.getColor();
+    }
+
     @Override
     public Pos tryActivate(Pony player) {
 

src/main/java/com/minelittlepony/unicopia/ability/magic/SpellPredicate.java

@@ -16,11 +16,22 @@ public interface SpellPredicate<T extends Spell> extends Predicate<Spell> {
     SpellPredicate<ShieldSpell> IS_SHIELD_LIKE = spell -> spell instanceof ShieldSpell;
     SpellPredicate<TimedSpell> IS_TIMED = spell -> spell instanceof TimedSpell;
 
+    SpellPredicate<?> IS_NOT_PLACED = IS_PLACED.negate();
+
     default <Q extends Spell> SpellPredicate<Q> and(SpellPredicate<Q> predicate) {
         SpellPredicate<T> self = this;
-        return s -> {
-            return self.test(s) && predicate.test(s);
-        };
+        return s -> self.test(s) && predicate.test(s);
+    }
+
+    default <Q extends Spell> SpellPredicate<? extends Spell> or(SpellPredicate<Q> predicate) {
+        SpellPredicate<T> self = this;
+        return s -> self.test(s) || predicate.test(s);
+    }
+
+    @Override
+    default SpellPredicate<?> negate() {
+        SpellPredicate<T> self = this;
+        return s -> !self.test(s);
     }
 
     default boolean isOn(Caster<?> caster) {

src/main/java/com/minelittlepony/unicopia/client/URenderers.java

@@ -61,6 +61,7 @@ public interface URenderers {
         AccessoryFeatureRenderer.register(BraceletFeatureRenderer::new);
         AccessoryFeatureRenderer.register(AmuletFeatureRenderer::new);
         AccessoryFeatureRenderer.register(WingsFeatureRenderer::new);
+        AccessoryFeatureRenderer.register(HornFeatureRenderer::new);
         AccessoryFeatureRenderer.register(IcarusWingsFeatureRenderer::new);
         AccessoryFeatureRenderer.register(BatWingsFeatureRenderer::new);
         AccessoryFeatureRenderer.register(GlassesFeatureRenderer::new);

src/main/java/com/minelittlepony/unicopia/client/render/HornFeatureRenderer.java

@@ -0,0 +1,108 @@
+package com.minelittlepony.unicopia.client.render;
+
+import com.minelittlepony.unicopia.Unicopia;
+import com.minelittlepony.unicopia.entity.player.Pony;
+import com.minelittlepony.unicopia.ability.AbilityDispatcher.Stat;
+import com.minelittlepony.unicopia.ability.magic.SpellPredicate;
+
+import net.minecraft.client.model.Dilation;
+import net.minecraft.client.model.Model;
+import net.minecraft.client.model.ModelData;
+import net.minecraft.client.model.ModelPart;
+import net.minecraft.client.model.ModelPartBuilder;
+import net.minecraft.client.model.ModelPartData;
+import net.minecraft.client.model.ModelTransform;
+import net.minecraft.client.model.TexturedModelData;
+import net.minecraft.client.render.OverlayTexture;
+import net.minecraft.client.render.RenderLayer;
+import net.minecraft.client.render.VertexConsumer;
+import net.minecraft.client.render.VertexConsumerProvider;
+import net.minecraft.client.render.entity.feature.FeatureRendererContext;
+import net.minecraft.client.render.entity.model.BipedEntityModel;
+import net.minecraft.client.render.entity.model.EntityModelPartNames;
+import net.minecraft.client.render.item.ItemRenderer;
+import net.minecraft.client.util.math.MatrixStack;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.util.*;
+import net.minecraft.util.math.MathHelper;
+
+public class HornFeatureRenderer<E extends LivingEntity> implements AccessoryFeatureRenderer.Feature<E> {
+
+    public static final Identifier TEXTURE = Unicopia.id("textures/models/horn/unicorn.png");
+
+    private final HornModel model;
+
+    private final FeatureRendererContext<E, ? extends BipedEntityModel<E>> context;
+
+    public HornFeatureRenderer(FeatureRendererContext<E, ? extends BipedEntityModel<E>> context) {
+        this.context = context;
+        model = new HornModel(HornModel.getData(Dilation.NONE).createModel());
+    }
+
+    protected boolean canRender(E entity) {
+        return entity instanceof PlayerEntity player && Pony.of(player).getObservedSpecies().canCast();
+    }
+
+    @Override
+    public void render(MatrixStack stack, VertexConsumerProvider renderContext, int lightUv, E entity, float limbDistance, float limbAngle, float tickDelta, float age, float headYaw, float headPitch) {
+        if (canRender(entity)) {
+            model.setAngles(context.getModel());
+            model.setState(false);
+            model.render(stack, ItemRenderer.getArmorGlintConsumer(renderContext, RenderLayer.getArmorCutoutNoCull(TEXTURE), false, false), lightUv, OverlayTexture.DEFAULT_UV, 1, 1, 1, 1);
+
+            Pony.of(entity).flatMap(pony -> {
+                return pony.getAbilities().getActiveStat()
+                        .flatMap(Stat::getActiveAbility)
+                        .map(ability -> ability.getColor(pony))
+                        .filter(i -> i != -1).or(() -> pony.getSpellSlot().get(SpellPredicate.IS_NOT_PLACED, false).map(spell -> spell.getType().getColor()));
+            }).ifPresent(color -> {
+                model.setState(true);
+                model.render(stack, ItemRenderer.getArmorGlintConsumer(renderContext, RenderLayers.getMagicColored(color), false, false), lightUv, OverlayTexture.DEFAULT_UV, 1, 1, 1, 1);
+            });
+        }
+    }
+
+    public static class HornModel extends Model {
+
+        private final ModelPart part;
+
+        public HornModel(ModelPart tree) {
+            super(RenderLayer::getEntityTranslucent);
+            part = tree.getChild(EntityModelPartNames.HEAD);
+        }
+
+        public static TexturedModelData getData(Dilation dilation) {
+            ModelData data = new ModelData();
+            ModelPartData root = data.getRoot();
+
+            ModelPartData head = root.addChild(EntityModelPartNames.HEAD, ModelPartBuilder.create()
+                        .uv(0, 0)
+                        .cuboid(-4, -8, -4, 8, 8, 8, dilation), ModelTransform.NONE);
+            head.addChild("horn", ModelPartBuilder.create()
+                        .uv(0, 3)
+                        .cuboid(-0.5F, -11, -3.5F, 1, 4, 1, dilation), ModelTransform.rotation(29 * MathHelper.RADIANS_PER_DEGREE, 0, 0));
+            head.addChild("magic", ModelPartBuilder.create()
+                    .uv(0, 3)
+                    .cuboid(-0.5F, -11, -3.5F, 1, 4, 1, dilation.add(0.5F)), ModelTransform.rotation(29 * MathHelper.RADIANS_PER_DEGREE, 0, 0));
+
+            return TexturedModelData.of(data, 64, 64);
+        }
+
+        public void setAngles(BipedEntityModel<?> biped) {
+            part.copyTransform(biped.getHead());
+        }
+
+        public void setState(boolean magic) {
+            part.hidden = true;
+            part.getChild("horn").visible = !magic;
+            part.getChild("magic").visible = magic;
+        }
+
+        @Override
+        public void render(MatrixStack matrixStack, VertexConsumer vertexConsumer, int i, int j, float f, float g, float h, float k) {
+            part.render(matrixStack, vertexConsumer, i, j, f, g, h, k);
+        }
+    }
+
+}