Decimation_Mod/Content/NPCs/CoreSpiderWall.cs

using Decimation.Content.Tiles.ShrineoftheMoltenOne;
using Decimation.Lib.Util;
using Microsoft.Xna.Framework;
using Terraria;
using Terraria.ID;
using Terraria.ModLoader;

namespace Decimation.Content.NPCs
{
    // Check  line 43861 of NPC.cs
    internal class CoreSpiderWall : ModNPC
    {
        private const int AnimationFps = 10;
        private const int AnimationFrameCount = 4;
        private const float Speed = 2;
        private const int ShootInterval = 120;
        private int _frame;

        public override void SetStaticDefaults()
        {
            DisplayName.SetDefault("Core Spider");
            Main.npcFrameCount[npc.type] = AnimationFrameCount;
        }

        public override void SetDefaults()
        {
            npc.width = 52;
            npc.height = 52;
            npc.aiStyle = -1;
            npc.lifeMax = 750;
            npc.knockBackResist = 0.25f;
            npc.lavaImmune = true;
            npc.value = 7000;
            npc.buffImmune[20] = true;
            npc.buffImmune[31] = false;
            npc.buffImmune[BuffID.OnFire] = true;
            npc.buffImmune[BuffID.Burning] = true;
            npc.timeLeft = NPC.activeTime * 2;
            npc.noGravity = true;
            npc.HitSound = SoundID.NPCHit19;
            npc.DeathSound = SoundID.NPCDeath12;
        }

        public override bool PreAI()
        {
            Lighting.AddLight(npc.Center, LightingUtils.Rgb255ToRgb1(255, 155, 48));
            return true;
        }

        public override void AI()
        {
            if (npc.target >= 255) npc.TargetClosest();
            Player target = Main.player[npc.target];
            if (npc.Distance(target.position) > 480) npc.target = 255;
            if (!Collision.CanHitLine(npc.position, npc.width, npc.height, target.position, target.width, target.height)
            ) npc.target = 255;
            bool hasTarget = npc.target < 255 && target.active && !target.dead;

            // Rotation
            if (hasTarget)
            {
                Vector2 distance = target.Center - npc.Center;
                if (distance.Length() > 0)
                {
                    float rotation = distance.ToRotation();
                    npc.rotation = rotation;
                }
            }
            else
            {
                npc.rotation += Main.rand.NextFloat(-0.05f, 0.05f);
            }

            Vector2 velocity = new Vector2(1, 0);
            velocity.Normalize();
            velocity *= Speed;
            npc.velocity = velocity.RotatedBy(npc.rotation);

            if (!hasTarget)
            {
                Vector2 frontTilePosition = npc.Center;
                frontTilePosition += new Vector2(npc.width / 2f + 16, 0).RotatedBy(npc.rotation);
                int frontTileX = (int) frontTilePosition.X / 16;
                int frontTileY = (int) frontTilePosition.Y / 16;
                Tile frontTile = Main.tile[frontTileX, frontTileY];
                Tile frontTileY1 = Main.tile[frontTileX, frontTileY + 1];
                Tile frontTileY2 = Main.tile[frontTileX, frontTileY - 1];

                if (frontTile == null) frontTile = new Tile();
                if (frontTileY1.nactive() && Main.tileSolid[frontTileY1.type] &&
                    !Main.tileSolidTop[frontTileY1.type] &&
                    (!frontTileY2.nactive() || !Main.tileSolid[frontTileY2.type] ||
                     Main.tileSolidTop[frontTileY2.type]))
                    npc.rotation += MathHelper.PiOver2;
                else if (frontTileY2.nactive() && Main.tileSolid[frontTileY2.type] &&
                         !Main.tileSolidTop[frontTileY2.type] &&
                         (!frontTileY1.nactive() || !Main.tileSolid[frontTileY1.type] ||
                          Main.tileSolidTop[frontTileY1.type]))
                    npc.rotation -= MathHelper.PiOver2;
                else if (frontTile.nactive() && Main.tileSolid[frontTile.type] && !Main.tileSolidTop[frontTile.type])
                    npc.rotation += MathHelper.Pi;
            }

            int currentTileX = (int) npc.Center.X / 16;
            int currentTileY = (int) npc.Center.Y / 16;
            bool onWall = false;
            for (int x = currentTileX - 1; x <= currentTileX + 1; x++)
            {
                for (int y = currentTileY - 1; y <= currentTileY + 1; y++)
                {
                    if (Main.tile[x, y].wall > 0) onWall = true;
                }
            }

            if (!onWall) npc.Transform(ModContent.NPCType<CoreSpider>());

            if (Main.expertMode && hasTarget)
            {
                if (_frame >= ShootInterval)
                {
                    if (Main.rand.Next(4) == 0)
                    {
                        Vector2 mouthPos = npc.Center + new Vector2(npc.width / 2f, 0).RotatedBy(npc.rotation);
                        Vector2 projSpeed = new Vector2(5, 0).RotatedBy(npc.rotation);

                        Projectile.NewProjectile(mouthPos, projSpeed, ProjectileID.Fireball, 130, 30);
                    }

                    _frame = 0;
                }
                else
                {
                    _frame++;
                }
            }

            if (npc.spriteDirection == -1) npc.spriteDirection = 1;
        }

        public override void FindFrame(int frameHeight)
        {
            if (++npc.frameCounter >= 60f / AnimationFps)
            {
                npc.frameCounter = 0;

                npc.frame.Y += frameHeight;
                if (npc.frame.Y / frameHeight >= AnimationFrameCount) npc.frame.Y = 0;
            }
        }

        public override bool CheckConditions(int left, int right, int top, int bottom)
        {
            int x = (int) Main.LocalPlayer.position.X / 16;
            int y = (int) Main.LocalPlayer.position.Y / 16;

            int validBlockCount = 0;
            for (int i = (int) (-50 + x / 16f); i <= (int) (50 + x / 16f); i++)
            for (int j = (int) (-50 + y / 16f); j <= (int) (50 + y / 16f); j++)
                if (i >= 0 && i <= Main.maxTilesX && j >= 0 && j <= Main.maxTilesY)
                    if (Main.tile[i, j].type == ModContent.TileType<ShrineBrick>() ||
                        Main.tile[i, j].type == ModContent.TileType<LockedShrineDoor>() ||
                        Main.tile[i, j].type == ModContent.TileType<ShrineDoorClosed>() ||
                        Main.tile[i, j].type == ModContent.TileType<ShrineDoorOpened>() ||
                        Main.tile[i, j].type == ModContent.TileType<RedHotSpike>())
                        validBlockCount++;

            return validBlockCount >= 15 && Main.hardMode;
        }
    }
}