Added a homing ability to the firebolt spell

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

@@ -6,14 +6,18 @@ import org.jetbrains.annotations.Nullable;
 
 import com.minelittlepony.unicopia.Race;
 import com.minelittlepony.unicopia.ability.data.Hit;
+import com.minelittlepony.unicopia.ability.magic.spell.HomingSpell;
+import com.minelittlepony.unicopia.ability.magic.spell.Spell;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.CustomisedSpellType;
 import com.minelittlepony.unicopia.entity.player.Pony;
 import com.minelittlepony.unicopia.item.AmuletItem;
 import com.minelittlepony.unicopia.particle.MagicParticleEffect;
+import com.minelittlepony.unicopia.util.RayTraceHelper;
 import com.minelittlepony.unicopia.util.VecHelper;
 
 import net.minecraft.item.ItemStack;
 import net.minecraft.particle.ParticleTypes;
+import net.minecraft.predicate.entity.EntityPredicates;
 import net.minecraft.sound.SoundCategory;
 import net.minecraft.sound.SoundEvents;
 import net.minecraft.util.ActionResult;
@@ -97,10 +101,14 @@ public class UnicornCastingAbility implements Ability<Hit> {
                 boolean remove = player.getSpellSlot().removeIf(spell, true);
                 player.subtractEnergyCost(remove ? 2 : 4);
                 if (!remove) {
-                    if (spell.apply(player) == null) {
+                    Spell s = spell.apply(player);
+                    if (s == null) {
                         player.spawnParticles(ParticleTypes.LARGE_SMOKE, 6);
                         player.playSound(SoundEvents.ENTITY_ITEM_BREAK, 1, 0.5F);
                     } else {
+                        if (s instanceof HomingSpell) {
+                            RayTraceHelper.doTrace(player.getMaster(), 600, 1, EntityPredicates.EXCEPT_SPECTATOR).getEntity().ifPresent(((HomingSpell)s)::setTarget);
+                        }
                         player.playSound(SoundEvents.BLOCK_BEACON_POWER_SELECT, 0.05F, 2.2F);
                     }
                 }

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

@@ -2,10 +2,14 @@ package com.minelittlepony.unicopia.ability;
 
 import com.minelittlepony.unicopia.Race;
 import com.minelittlepony.unicopia.ability.data.Hit;
+import com.minelittlepony.unicopia.ability.magic.spell.HomingSpell;
+import com.minelittlepony.unicopia.ability.magic.spell.Spell;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.CustomisedSpellType;
 import com.minelittlepony.unicopia.entity.player.Pony;
 import com.minelittlepony.unicopia.particle.MagicParticleEffect;
+import com.minelittlepony.unicopia.util.RayTraceHelper;
 
+import net.minecraft.predicate.entity.EntityPredicates;
 import net.minecraft.util.ActionResult;
 import net.minecraft.util.Hand;
 import net.minecraft.util.Identifier;
@@ -61,7 +65,16 @@ public class UnicornProjectileAbility implements Ability<Hit> {
 
         if (thrown.getResult() != ActionResult.FAIL) {
             player.subtractEnergyCost(getCostEstimate(player));
-            thrown.getValue().create().toThrowable().throwProjectile(player);
+
+            Spell spell = thrown.getValue().create();
+
+            spell.toThrowable().throwProjectile(player).ifPresent(projectile -> {
+                if (spell instanceof HomingSpell) {
+                    RayTraceHelper.doTrace(player.getMaster(), 600, 1, EntityPredicates.EXCEPT_SPECTATOR).getEntity().filter(((HomingSpell)spell)::setTarget).ifPresent(target -> {
+                        projectile.setHomingTarget(target);
+                    });
+                }
+            });
         }
     }
 

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/HomingSpell.java

@@ -0,0 +1,10 @@
+package com.minelittlepony.unicopia.ability.magic.spell;
+
+import net.minecraft.entity.Entity;
+
+/**
+ * A spell that's capable of homing in on a pre-defined target.
+ */
+public interface HomingSpell extends Spell {
+    boolean setTarget(Entity target);
+}

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/ThrowableSpell.java

@@ -40,6 +40,15 @@ public final class ThrowableSpell extends AbstractDelegatingSpell {
      * Returns the resulting projectile entity for customization (or null if on the client).
      */
     public Optional<MagicProjectileEntity> throwProjectile(Caster<?> caster) {
+        return throwProjectile(caster, 1);
+    }
+
+    /**
+     * Projects this spell.
+     *
+     * Returns the resulting projectile entity for customization (or null if on the client).
+     */
+    public Optional<MagicProjectileEntity> throwProjectile(Caster<?> caster, float divergance) {
         World world = caster.getWorld();
 
         LivingEntity entity = caster.getMaster();
@@ -51,7 +60,7 @@ public final class ThrowableSpell extends AbstractDelegatingSpell {
 
             projectile.setItem(GemstoneItem.enchant(UItems.GEMSTONE.getDefaultStack(), spell.getType()));
             projectile.getSpellSlot().put(this);
-            projectile.setVelocity(entity, entity.getPitch(), entity.getYaw(), 0, 1.5F, 1);
+            projectile.setVelocity(entity, entity.getPitch(), entity.getYaw(), 0, 1.5F, divergance);
             projectile.setHydrophobic();
             configureProjectile(projectile, caster);
             world.spawnEntity(projectile);

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/FireBoltSpell.java

@@ -1,21 +1,35 @@
 package com.minelittlepony.unicopia.ability.magic.spell.effect;
 
+import org.jetbrains.annotations.Nullable;
+
 import com.minelittlepony.unicopia.ability.magic.Caster;
+import com.minelittlepony.unicopia.ability.magic.spell.HomingSpell;
 import com.minelittlepony.unicopia.ability.magic.spell.ProjectileSpell;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.Trait;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
-
 import net.minecraft.entity.Entity;
 import net.minecraft.item.Items;
+import net.minecraft.predicate.entity.EntityPredicates;
 import net.minecraft.sound.SoundEvents;
 
-public class FireBoltSpell extends AbstractSpell implements ProjectileSpell {
+public class FireBoltSpell extends AbstractSpell implements ProjectileSpell, HomingSpell {
     public static final SpellTraits DEFAULT_TRAITS = new SpellTraits.Builder()
-            .with(Trait.FIRE, 90)
-            .with(Trait.AIR, 60)
+            .with(Trait.FOCUS, 10)
+            .with(Trait.CHAOS, 1)
+            .with(Trait.STRENGTH, 11)
+            .with(Trait.FIRE, 60)
             .build();
+    public static final SpellTraits HOMING_TRAITS = new SpellTraits.Builder()
+            .with(Trait.FOCUS, 50)
+            .with(Trait.CHAOS, 10)
+            .with(Trait.STRENGTH, 11)
+            .with(Trait.FIRE, 60)
+            .build();
+
+    @Nullable
+    private Entity target;
 
     protected FireBoltSpell(SpellType<?> type, SpellTraits traits) {
         super(type, traits);
@@ -29,11 +43,30 @@ public class FireBoltSpell extends AbstractSpell implements ProjectileSpell {
     @Override
     public boolean tick(Caster<?> caster, Situation situation) {
         if (situation == Situation.PROJECTILE) {
+            if (caster instanceof MagicProjectileEntity && getTraits().get(Trait.FOCUS) >= 50) {
+                caster.findAllEntitiesInRange(
+                    getTraits().get(Trait.FOCUS) - 49,
+                    EntityPredicates.VALID_LIVING_ENTITY.and(TargetSelecter.notOwnerOrFriend(this, caster))
+                ).findFirst().ifPresent(target -> {
+                    ((MagicProjectileEntity)caster).setHomingTarget(target);
+                });
+            }
+
             return true;
         }
 
+        if (getTraits().get(Trait.FOCUS) >= 50 && target == null) {
+            target = caster.findAllEntitiesInRange(
+                getTraits().get(Trait.FOCUS) - 49,
+                EntityPredicates.VALID_LIVING_ENTITY.and(TargetSelecter.notOwnerOrFriend(this, caster))
+            ).findFirst().orElse(null);
+        }
+
         for (int i = 0; i < getNumberOfBalls(caster); i++) {
-            getType().create(getTraits()).toThrowable().throwProjectile(caster);
+            getType().create(getTraits()).toThrowable().throwProjectile(caster, 2).ifPresent(c -> {
+                c.setHomingTarget(target);
+            });
+
             caster.playSound(SoundEvents.ENTITY_BLAZE_SHOOT, 0.7F, 0.4F / (caster.getWorld().random.nextFloat() * 0.4F + 0.8F));
         }
         return false;
@@ -42,12 +75,21 @@ public class FireBoltSpell extends AbstractSpell implements ProjectileSpell {
     @Override
     public void configureProjectile(MagicProjectileEntity projectile, Caster<?> caster) {
         projectile.setItem(Items.FIRE_CHARGE.getDefaultStack());
-        projectile.addThrowDamage(getTraits().get(Trait.FIRE) / 10F);
+        projectile.addThrowDamage(getTraits().get(Trait.POWER, 0, getTraits().get(Trait.FOCUS) >= 50 ? 500 : 50) / 10F);
         projectile.setFireTicks(900000);
-        projectile.setVelocity(projectile.getVelocity().multiply(1.3 + getTraits().get(Trait.STRENGTH)));
+        projectile.setVelocity(projectile.getVelocity().multiply(1.3 + getTraits().get(Trait.STRENGTH) / 11F));
     }
 
     protected int getNumberOfBalls(Caster<?> caster) {
-        return 1 + caster.getWorld().random.nextInt(3) + (int)getTraits().get(Trait.POWER) * 3;
+        return 1 + caster.getWorld().random.nextInt(3) + (int)getTraits().get(Trait.EARTH) * 3;
+    }
+
+    @Override
+    public boolean setTarget(Entity target) {
+        if (getTraits().get(Trait.FOCUS) >= 50) {
+            this.target = target;
+            return true;
+        }
+        return false;
     }
 }

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/TargetSelecter.java

@@ -4,6 +4,7 @@ import java.util.Map;
 import java.util.TreeMap;
 import java.util.UUID;
 import java.util.function.BiPredicate;
+import java.util.function.Predicate;
 import java.util.stream.Stream;
 
 import com.minelittlepony.unicopia.EquinePredicates;
@@ -54,6 +55,20 @@ public class TargetSelecter {
         return targets.values().stream().filter(Target::canHurt).count();
     }
 
+    public static Predicate<Entity> notOwnerOrFriend(Spell spell, Caster<?> source) {
+        Entity owner = source.getMaster();
+
+        boolean ownerIsValid = spell.isFriendlyTogether(source) && (EquinePredicates.PLAYER_UNICORN.test(owner));
+
+        if (!ownerIsValid) {
+            return e -> true;
+        }
+
+        return entity -> {
+            return !ownerIsValid || !(Pony.equal(entity, owner) || owner.isConnectedThroughVehicle(entity) || FriendshipBraceletItem.isComrade(source, entity));
+        };
+    }
+
     static final class Target {
         private int cooldown = 20;
 

src/main/java/com/minelittlepony/unicopia/client/particle/ChangelingMagicParticle.java

@@ -3,20 +3,19 @@ package com.minelittlepony.unicopia.client.particle;
 import net.minecraft.client.particle.SpriteProvider;
 import net.minecraft.client.world.ClientWorld;
 import net.minecraft.particle.ParticleEffect;
+import net.minecraft.util.math.Vec3f;
 
 public class ChangelingMagicParticle extends MagicParticle {
 
     private final SpriteProvider provider;
 
     public ChangelingMagicParticle(ParticleEffect effect, SpriteProvider provider, ClientWorld world, double x, double y, double z, double dx, double dy, double dz) {
-        super(effect, provider, world, x, y, z, dx, dy, dz, 1, 1, 1);
+        super(effect, provider, world, x, y, z, dx, dy, dz, nextColor(world.random.nextFloat() * 0.6F + 0.4F), 1);
         this.provider = provider;
+    }
 
-        float intensity = random.nextFloat() * 0.6F + 0.4F;
-
-        colorRed = intensity * 0.5F;
-        colorGreen = intensity;
-        colorBlue = intensity * 0.4f;
+    static Vec3f nextColor(float intensity) {
+        return new Vec3f(intensity * 0.5F, intensity, intensity * 0.4F);
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/client/particle/MagicParticle.java

@@ -7,13 +7,14 @@ import net.minecraft.client.particle.SpriteBillboardParticle;
 import net.minecraft.client.particle.SpriteProvider;
 import net.minecraft.client.world.ClientWorld;
 import net.minecraft.particle.ParticleEffect;
+import net.minecraft.util.math.Vec3f;
 
 public class MagicParticle extends SpriteBillboardParticle {
-    private double startX;
-    private double startY;
-    private double startZ;
+    private final double startX;
+    private final double startY;
+    private final double startZ;
 
-    MagicParticle(ParticleEffect effect, SpriteProvider provider, ClientWorld w, double x, double y, double z, double vX, double vY, double vZ, float r, float g, float b) {
+    MagicParticle(ParticleEffect effect, SpriteProvider provider, ClientWorld w, double x, double y, double z, double vX, double vY, double vZ, Vec3f color, float alpha) {
         super(w, x, y, z);
         setSprite(provider);
 
@@ -26,41 +27,14 @@ public class MagicParticle extends SpriteBillboardParticle {
         scale = random.nextFloat() * 0.12F;
         maxAge = (int)(Math.random() * 10) + 20;
 
-        colorRed = r;
-        colorGreen = g;
-        colorBlue = b;
+        colorRed = color.getX();
+        colorGreen = color.getY();
+        colorBlue = color.getZ();
+        colorAlpha = alpha;
     }
 
-    public MagicParticle(ParticleEffect effect, SpriteProvider provider, ClientWorld w, double x, double y, double z, double vX, double vY, double vZ) {
-        this(effect, provider, w, x, y, z, vX, vY, vZ, 1, 1, 1);
-
-        colorAlpha = 0.7F;
-        colorGreen *= 0.3F;
-
-        if (effect instanceof MagicParticleEffect && ((MagicParticleEffect)effect).hasTint()) {
-            MagicParticleEffect parameters = (MagicParticleEffect)effect;
-
-            colorRed = parameters.getColor().getX();
-            colorGreen = parameters.getColor().getY();
-            colorBlue = parameters.getColor().getZ();
-        } else {
-
-            if (random.nextBoolean()) {
-                colorBlue *= 0.4F;
-            }
-            if (random.nextBoolean()) {
-                colorRed *= 0.9F;
-            }
-            if (random.nextBoolean()) {
-                colorGreen += 0.5F;
-            }
-
-            if (random.nextBoolean()) {
-                colorGreen *= 2F;
-            } else if (random.nextBoolean()) {
-                colorRed *= 3.9F;
-            }
-        }
+    public MagicParticle(MagicParticleEffect effect, SpriteProvider provider, ClientWorld w, double x, double y, double z, double vX, double vY, double vZ) {
+        this(effect, provider, w, x, y, z, vX, vY, vZ, effect.getColor(w.random), 0.7F);
     }
 
     @Override
@@ -80,7 +54,7 @@ public class MagicParticle extends SpriteBillboardParticle {
         float timer = (float)age / (float)maxAge;
 
         int v = light >> 16 & 255;
-        v = (int)Math.min(v + Math.pow(timer, 4) * 240, 240);
+        v = (int)Math.min(v + (timer * timer * timer * timer) * 240, 240);
 
         return (light & 255) | v << 16;
     }
@@ -95,7 +69,8 @@ public class MagicParticle extends SpriteBillboardParticle {
             markDead();
         } else {
             float timer = (float)age / (float)maxAge;
-            timer = 1 + timer - timer * timer * 2;
+
+            timer += 1 - (timer * timer) * 2;
 
             x = startX + velocityX * timer;
             y = startY + velocityY;

src/main/java/com/minelittlepony/unicopia/particle/MagicParticleEffect.java

@@ -1,6 +1,7 @@
 package com.minelittlepony.unicopia.particle;
 
 import java.util.Locale;
+import java.util.Random;
 
 import com.minelittlepony.common.util.Color;
 import com.mojang.brigadier.StringReader;
@@ -46,8 +47,22 @@ public class MagicParticleEffect implements ParticleEffect {
         return tinted;
     }
 
-    public Vec3f getColor() {
-        return color;
+    public Vec3f getColor(Random random) {
+        if (hasTint()) {
+            return color;
+        }
+
+        float r = random.nextBoolean() ? 0.9F : 1;
+        float g = 0.3F;
+        float b = random.nextBoolean() ? 0.4F : 1;
+
+        if (random.nextBoolean()) {
+            g *= 2F;
+        } else if (random.nextBoolean()) {
+            r *= 3.9F;
+        }
+
+        return new Vec3f(r, g, b);
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/projectile/MagicProjectileEntity.java

@@ -2,6 +2,8 @@ package com.minelittlepony.unicopia.projectile;
 
 import java.util.function.Consumer;
 
+import org.jetbrains.annotations.Nullable;
+
 import com.minelittlepony.unicopia.Affinity;
 import com.minelittlepony.unicopia.ability.magic.Affine;
 import com.minelittlepony.unicopia.ability.magic.Caster;
@@ -12,6 +14,7 @@ import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.Spell;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.entity.EntityPhysics;
+import com.minelittlepony.unicopia.entity.EntityReference;
 import com.minelittlepony.unicopia.entity.Physics;
 import com.minelittlepony.unicopia.entity.UEntities;
 import com.minelittlepony.unicopia.item.UItems;
@@ -58,6 +61,8 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
 
     private final EntityPhysics<MagicProjectileEntity> physics = new EntityPhysics<>(this, GRAVITY, false);
 
+    private final EntityReference<Entity> homingTarget = new EntityReference<>();
+
     public MagicProjectileEntity(EntityType<MagicProjectileEntity> type, World world) {
         super(type, world);
     }
@@ -94,6 +99,10 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
         setOwner(owner);
     }
 
+    public void setHomingTarget(@Nullable Entity target) {
+        homingTarget.set(target);
+    }
+
     @Override
     public LivingEntity getMaster() {
         return (LivingEntity)getOwner();
@@ -146,8 +155,8 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
 
     @Override
     public void tick() {
-        if (!world.isClient()) {
-            if (Math.abs(getVelocity().x) < 0.01 && Math.abs(getVelocity().x) < 0.01 && Math.abs(getVelocity().y) < 0.01) {
+        if (!world.isClient() && !homingTarget.isPresent(world)) {
+            if (getVelocity().length() < 0.01) {
                 discard();
             }
         }
@@ -175,6 +184,12 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
                 setVelocity(new Vec3d(vel.x, velY, vel.z));
             }
         }
+
+        homingTarget.ifPresent(world, e -> {
+            setNoGravity(true);
+            noClip = true;
+            setVelocity(getVelocity().add(e.getPos().subtract(getPos()).normalize().multiply(0.2)).multiply(0.6, 0.6, 0.6));
+        });
     }
 
     private ParticleEffect getParticleParameters() {
@@ -200,13 +215,13 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
              world.addParticle(effect, getX(), getY(), getZ(), 0, 0, 0);
           }
        }
-
     }
 
     @Override
     public void readCustomDataFromNbt(NbtCompound compound) {
         super.readCustomDataFromNbt(compound);
         physics.fromNBT(compound);
+        homingTarget.fromNBT(compound.getCompound("homingTarget"));
         if (compound.contains("effect")) {
             getSpellSlot().put(SpellType.fromNBT(compound.getCompound("effect")));
         }
@@ -216,6 +231,7 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
     public void writeCustomDataToNbt(NbtCompound compound) {
         super.writeCustomDataToNbt(compound);
         physics.toNBT(compound);
+        compound.put("homingTarget", homingTarget.toNBT());
         getSpellSlot().get(true).ifPresent(effect -> {
             compound.put("effect", SpellType.toNBT(effect));
         });

src/main/java/com/minelittlepony/unicopia/util/RayTraceHelper.java

@@ -7,6 +7,7 @@ import java.util.function.Predicate;
 import org.jetbrains.annotations.Nullable;
 
 import net.minecraft.entity.Entity;
+import net.minecraft.entity.projectile.ProjectileUtil;
 import net.minecraft.predicate.entity.EntityPredicates;
 import net.minecraft.util.hit.BlockHitResult;
 import net.minecraft.util.hit.EntityHitResult;
@@ -49,58 +50,18 @@ public class RayTraceHelper {
      * @return A Trace describing what was found.
      */
     public static Trace doTrace(Entity e, double distance, float tickDelta, Predicate<Entity> predicate) {
-        HitResult tracedBlock = e.raycast(distance, tickDelta, false);
-
+        final Vec3d ray = e.getRotationVec(tickDelta).multiply(distance);
         final Vec3d start = e.getCameraPosVec(tickDelta);
 
-        final double totalTraceDistance = tracedBlock == null ? distance : tracedBlock.getPos().distanceTo(start);
+        final Box box = e.getBoundingBox().stretch(ray).expand(1);
 
-        final Vec3d ray = e.getRotationVec(tickDelta).multiply(distance);
-        final Vec3d end = start.add(ray);
+        EntityHitResult pointedEntity = ProjectileUtil.raycast(e, start, start.add(ray), box, predicate.and(Entity::collides), distance);
 
-        Vec3d hit = null;
-        Entity pointedEntity = null;
-
-        double traceDistance = totalTraceDistance;
-
-        for (Entity entity : e.world.getOtherEntities(e,
-                e.getBoundingBox().expand(ray.x + 1, ray.y + 1, ray.z + 1),
-                predicate.and(Entity::collides)
-        )) {
-            Box entityAABB = entity.getBoundingBox().expand(entity.getTargetingMargin());
-
-            Optional<Vec3d> intercept = entityAABB.raycast(start, end);
-
-            if (entityAABB.contains(start)) {
-                if (traceDistance <= 0) {
-                    pointedEntity = entity;
-                    hit = intercept.orElse(null);
-                    traceDistance = 0;
-                }
-            } else if (intercept.isPresent()) {
-                Vec3d inter = intercept.get();
-                double distanceToHit = start.distanceTo(inter);
-
-                if (distanceToHit < traceDistance || traceDistance == 0) {
-                    if (entity.getRootVehicle() == e.getRootVehicle()) {
-                        if (traceDistance == 0) {
-                            pointedEntity = entity;
-                            hit = inter;
-                        }
-                    } else {
-                        pointedEntity = entity;
-                        hit = inter;
-                        traceDistance = distanceToHit;
-                    }
-                }
-            }
+        if (pointedEntity != null) {
+            return new Trace(pointedEntity);
         }
 
-        if (pointedEntity != null && (traceDistance < totalTraceDistance || tracedBlock == null)) {
-            return new Trace(new EntityHitResult(pointedEntity, hit));
-        }
-
-        return new Trace(tracedBlock);
+        return new Trace(e.raycast(distance, tickDelta, false));
     }
 
     public static class Trace {