EntityPawn.java

package minechess.common;

import java.util.ArrayList;
import java.util.List;

import minechess.common.network.NetworkHandler;
import minechess.common.network.PacketOpenPromotionGUI;
import net.minecraft.entity.Entity;
import net.minecraft.entity.EntityList;
import net.minecraft.entity.monster.EntityZombie;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraft.util.EnumParticleTypes;
import net.minecraft.world.World;

/**
 * MineChess
 * @author MineMaarten
 * www.minemaarten.com
 * @license Lesser GNU Public License v3 (http://www.gnu.org/licenses/lgpl.html)
 */

public class EntityPawn extends EntityBaseChessPiece{

    public EntityPawn(World par1World){
        super(par1World);
        setSize(0.4F, 0.93F);
    }

    @Override
    public Entity getMob(){
        return new EntityZombie(worldObj);
    }

    @Override
    public List<int[]> getPossibleMoves(){
        List<int[]> moves = new ArrayList<int[]>();
        int[] move1 = new int[2];
        move1[0] = targetX;
        move1[1] = targetZ + (isBlack() ? -1 : 1); // we don't have to check boundaries, as pawns are immeadiatly transformed into queens on the max Z.
        if(firstMove) {
            int[] move2 = new int[2];
            move2[0] = targetX;
            move2[1] = targetZ + (isBlack() ? -2 : 2);
            if(!isEnemyAt(move2[0], move2[1])) moves.add(move2);
        }
        if(!isEnemyAt(move1[0], move1[1])) moves.add(move1);

        // capturing rules
        if(isEnemyAt(targetX + 1, targetZ + (isBlack() ? -1 : 1))) {
            int[] move3 = new int[2];
            move3[0] = targetX + 1;
            move3[1] = targetZ + (isBlack() ? -1 : 1);
            moves.add(move3);
        }
        if(isEnemyAt(targetX - 1, targetZ + (isBlack() ? -1 : 1))) {
            int[] move4 = new int[2];
            move4[0] = targetX - 1;
            move4[1] = targetZ + (isBlack() ? -1 : 1);
            moves.add(move4);
        }
        return moves;
    }

    // returns true if there is an enemy at the given x,z. It also returns true
    // if there can be enPassanted.
    private boolean isEnemyAt(int x, int z){
        List<EntityBaseChessPiece> pieces = getChessPieces(true);
        for(int i = 0; i < pieces.size(); i++) {
            if(pieces.get(i).getTargetPosition()[0] == x && (pieces.get(i).getTargetPosition()[1] == z || pieces.get(i).enPassantPossibility && pieces.get(i).targetZ == targetZ) && pieces.get(i).isBlack() ^ isBlack()) {
                return true;
            }
        }
        return false;
    }

    public void promote(EntityPlayer player, String promotedPieceName){
        if(isPromoting() && !worldObj.isRemote && !isDead) {
            //Promote the pawn
            EntityBaseChessPiece promotedPiece = (EntityBaseChessPiece)EntityList.createEntityByName(promotedPieceName, worldObj);
            promotedPiece.setPosition(posX, posY, posZ);
            promotedPiece.xOffset = xOffset;
            promotedPiece.zOffset = zOffset;
            promotedPiece.setTargetPosition(targetX, targetZ);
            promotedPiece.setIsBlack(isBlack());
            worldObj.spawnEntityInWorld(promotedPiece);
            setDead();
            for(int i = 0; i < 40; i++) {
                MineChessUtils.spawnParticle(EnumParticleTypes.EXPLOSION_NORMAL, worldObj, posX, posY + rand.nextDouble() * 1.5D, posZ, rand.nextDouble() / 10 - 0.05D, rand.nextDouble() / 10 - 0.05D, rand.nextDouble() / 10 - 0.05D);
            }
            handleAfterTurn(player);
        }
    }

    @Override
    public boolean interact(EntityPlayer player){
        if(!player.worldObj.isRemote && isPromoting() && player.getCurrentEquippedItem() != null && player.getCurrentEquippedItem().getItem() == MineChess.itemPieceMover && (player.inventory.getCurrentItem().getItemDamage() == 0 && isBlack() || player.inventory.getCurrentItem().getItemDamage() == 1 && !isBlack())) {
            NetworkHandler.sendTo(new PacketOpenPromotionGUI(this), (EntityPlayerMP)player);
        } else {
            super.interact(player);
        }
        return false;
    }

    private boolean isPromoting(){
        return targetZ % 7 == 0;
    }

    @Override
    protected void handleAfterTurn(EntityPlayer player){
        super.handleAfterTurn(player);
        if(computerPiece && isPawnAwaitingPromotion()) {//When AI promotes, let it always promote to a Queen.
            promote(player, "MineChess.Queen");
        }
    }
}