Combat script for all chromatic dragons!

Author: lare96

src/main/kotlin/game/game/combat/npcHooks/dragons/DragonFireCombatAttack.kt

@@ -0,0 +1,117 @@
+package game.combat.npcHooks.dragons
+
+import api.predef.*
+import engine.combat.prayer.CombatPrayer
+import game.item.consumable.potion.PotionEffect.Companion.hasAntiFire
+import game.player.Sound
+import io.luna.game.model.mob.Mob
+import io.luna.game.model.mob.Npc
+import io.luna.game.model.mob.Player
+import io.luna.game.model.mob.block.Animation
+import io.luna.game.model.mob.block.Graphic
+import io.luna.game.model.mob.combat.attack.MagicCombatAttack
+import io.luna.game.model.mob.combat.damage.CombatDamage
+import io.luna.game.model.mob.combat.damage.CombatDamageRequest
+import io.luna.game.model.mob.combat.damage.CombatDamageType
+import java.lang.Double.max
+import kotlin.math.floor
+
+/**
+ * A dragonfire-based [MagicCombatAttack] used by dragons.
+ *
+ * Protection against this attack is calculated from a combination of:
+ * - An anti-dragon shield
+ * - An antifire potion
+ * - Protect from Magic
+ *
+ * The total protection value is then used to reduce both the attack's effective
+ * accuracy and maximum damage.
+ *
+ * @param attacker The dragon performing the attack.
+ * @param victim The target of the attack.
+ * @param maxHit The maximum damage before protection is applied.
+ */
+class DragonFireCombatAttack(
+    attacker: Npc,
+    victim: Mob,
+    private val maxHit: Int = 50
+) : MagicCombatAttack<Npc>(
+    attacker,
+    victim,
+    DRAGON_FIRE_CAST_ANIMATION,
+    DRAGON_FIRE_START_GRAPHIC,
+    null,
+    null,
+    Sound.DRAGONBREATH,
+    null,
+    attacker.combatDef().attackSpeed,
+    1
+) {
+
+    companion object {
+
+        /**
+         * The standard anti-dragon shield item id.
+         */
+        val DRAGON_FIRE_SHIELD = 1540
+
+        /**
+         * The starting graphic displayed for the dragonfire attack.
+         */
+        val DRAGON_FIRE_START_GRAPHIC = Graphic(1, 100, 0)
+
+        /**
+         * The cast animation used when the dragon breathes fire.
+         */
+        val DRAGON_FIRE_CAST_ANIMATION = Animation(81)
+    }
+
+    /**
+     * The total protection currently applied against this dragonfire attack.
+     *
+     * This value is built from the victim's active defensive sources during damage calculation.
+     */
+    private var protection = 0.0
+
+    /**
+     * Calculates the dragonfire damage against the supplied target.
+     *
+     * If the target is a player, the following protection values are added:
+     * - Anti-dragon shield: 80%
+     * - Antifire potion: 20%
+     * - Protect from Magic: 40%
+     *
+     * The final protection value is used to reduce:
+     * - Effective accuracy
+     * - Resulting maximum hit
+     *
+     * @param other The target being evaluated for damage.
+     * @return The resolved combat damage for this attack.
+     */
+    override fun calculateDamage(other: Mob?): CombatDamage {
+        if (other is Player) {
+            protection += if (other.equipment.shield?.id == DRAGON_FIRE_SHIELD) 0.80 else 0.0
+            protection += if (other.hasAntiFire()) 0.20 else 0.0
+            protection += if (other.combat.prayers.isActive(CombatPrayer.PROTECT_FROM_MAGIC)) 0.40 else 0.0
+        }
+
+        return CombatDamageRequest.Builder(attacker, victim, CombatDamageType.MAGIC)
+            .setFlatBonusAccuracy(max(1.0 - protection, 0.0))
+            .setBaseMaxHit((maxHit - floor(maxHit * protection).toInt()).coerceAtLeast(0))
+            .ignoreProtectionPrayers()
+            .build()
+            .resolve()
+    }
+
+    override fun onAttackArrived(damage: CombatDamage?) {
+        if (damage != null && damage.amount.isPresent && victim is Player) {
+            if (protection >= 0.8) {
+                victim.sendMessage("Your shield absorbs most of the dragon fire!")
+            } else if (protection <= 0.2) {
+                victim.sendMessage("You're horribly burnt by the dragon fire!")
+            } else {
+                victim.sendMessage("You manage to resist some of the dragon fire!")
+            }
+        }
+    }
+}

src/main/kotlin/game/game/combat/npcHooks/dragons/chromaticDragons.kts

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+package game.combat.npcHooks.dragons
+
+import api.combat.npc.NpcCombatHandler.combat
+import api.predef.*
+
+// Chromatic dragons have a small chance to deal dragonfire.
+combat(941, 55, 53, 54) {
+    attack {
+        if (rand(5) == 0) {
+            DragonFireCombatAttack(npc, other)
+        } else {
+            melee(animationId = if (rand(2) == 0) 91 else 80)
+        }
+    }
+}