Paper/src/main/java/net/minecraft/server/EntityProjectile.java

package net.minecraft.server;

import java.util.List;

public abstract class EntityProjectile extends Entity {

    private int blockX = -1;
    private int blockY = -1;
    private int blockZ = -1;
    private int inBlockId = 0;
    protected boolean inGround = false;
    public int shake = 0;
    public EntityLiving shooter; // CraftBukkit - prot to public
    private int h;
    private int i = 0;

    public EntityProjectile(World world) {
        super(world);
        this.b(0.25F, 0.25F);
    }

    protected void b() {}

    public EntityProjectile(World world, EntityLiving entityliving) {
        super(world);
        this.shooter = entityliving;
        this.b(0.25F, 0.25F);
        this.setPositionRotation(entityliving.locX, entityliving.locY + (double) entityliving.x(), entityliving.locZ, entityliving.yaw, entityliving.pitch);
        this.locX -= (double) (MathHelper.cos(this.yaw / 180.0F * 3.1415927F) * 0.16F);
        this.locY -= 0.10000000149011612D;
        this.locZ -= (double) (MathHelper.sin(this.yaw / 180.0F * 3.1415927F) * 0.16F);
        this.setPosition(this.locX, this.locY, this.locZ);
        this.height = 0.0F;
        float f = 0.4F;

        this.motX = (double) (-MathHelper.sin(this.yaw / 180.0F * 3.1415927F) * MathHelper.cos(this.pitch / 180.0F * 3.1415927F) * f);
        this.motZ = (double) (MathHelper.cos(this.yaw / 180.0F * 3.1415927F) * MathHelper.cos(this.pitch / 180.0F * 3.1415927F) * f);
        this.motY = (double) (-MathHelper.sin((this.pitch + this.d()) / 180.0F * 3.1415927F) * f);
        this.a(this.motX, this.motY, this.motZ, this.c(), 1.0F);
    }

    public EntityProjectile(World world, double d0, double d1, double d2) {
        super(world);
        this.h = 0;
        this.b(0.25F, 0.25F);
        this.setPosition(d0, d1, d2);
        this.height = 0.0F;
    }

    protected float c() {
        return 1.5F;
    }

    protected float d() {
        return 0.0F;
    }

    public void a(double d0, double d1, double d2, float f, float f1) {
        float f2 = MathHelper.a(d0 * d0 + d1 * d1 + d2 * d2);

        d0 /= (double) f2;
        d1 /= (double) f2;
        d2 /= (double) f2;
        d0 += this.random.nextGaussian() * 0.007499999832361937D * (double) f1;
        d1 += this.random.nextGaussian() * 0.007499999832361937D * (double) f1;
        d2 += this.random.nextGaussian() * 0.007499999832361937D * (double) f1;
        d0 *= (double) f;
        d1 *= (double) f;
        d2 *= (double) f;
        this.motX = d0;
        this.motY = d1;
        this.motZ = d2;
        float f3 = MathHelper.a(d0 * d0 + d2 * d2);

        this.lastYaw = this.yaw = (float) (Math.atan2(d0, d2) * 180.0D / 3.1415927410125732D);
        this.lastPitch = this.pitch = (float) (Math.atan2(d1, (double) f3) * 180.0D / 3.1415927410125732D);
        this.h = 0;
    }

    public void w_() {
        this.bI = this.locX;
        this.bJ = this.locY;
        this.bK = this.locZ;
        super.w_();
        if (this.shake > 0) {
            --this.shake;
        }

        if (this.inGround) {
            int i = this.world.getTypeId(this.blockX, this.blockY, this.blockZ);

            if (i == this.inBlockId) {
                ++this.h;
                if (this.h == 1200) {
                    this.die();
                }

                return;
            }

            this.inGround = false;
            this.motX *= (double) (this.random.nextFloat() * 0.2F);
            this.motY *= (double) (this.random.nextFloat() * 0.2F);
            this.motZ *= (double) (this.random.nextFloat() * 0.2F);
            this.h = 0;
            this.i = 0;
        } else {
            ++this.i;
        }

        Vec3D vec3d = Vec3D.create(this.locX, this.locY, this.locZ);
        Vec3D vec3d1 = Vec3D.create(this.locX + this.motX, this.locY + this.motY, this.locZ + this.motZ);
        MovingObjectPosition movingobjectposition = this.world.a(vec3d, vec3d1);

        vec3d = Vec3D.create(this.locX, this.locY, this.locZ);
        vec3d1 = Vec3D.create(this.locX + this.motX, this.locY + this.motY, this.locZ + this.motZ);
        if (movingobjectposition != null) {
            vec3d1 = Vec3D.create(movingobjectposition.f.a, movingobjectposition.f.b, movingobjectposition.f.c);
        }

        if (!this.world.isStatic) {
            Entity entity = null;
            List list = this.world.b((Entity) this, this.boundingBox.a(this.motX, this.motY, this.motZ).b(1.0D, 1.0D, 1.0D));
            double d0 = 0.0D;

            for (int j = 0; j < list.size(); ++j) {
                Entity entity1 = (Entity) list.get(j);

                if (entity1.e_() && (entity1 != this.shooter || this.i >= 5)) {
                    float f = 0.3F;
                    AxisAlignedBB axisalignedbb = entity1.boundingBox.b((double) f, (double) f, (double) f);
                    MovingObjectPosition movingobjectposition1 = axisalignedbb.a(vec3d, vec3d1);

                    if (movingobjectposition1 != null) {
                        double d1 = vec3d.b(movingobjectposition1.f);

                        if (d1 < d0 || d0 == 0.0D) {
                            entity = entity1;
                            d0 = d1;
                        }
                    }
                }
            }

            if (entity != null) {
                movingobjectposition = new MovingObjectPosition(entity);
            }
        }

        if (movingobjectposition != null) {
            this.a(movingobjectposition);
        }

        this.locX += this.motX;
        this.locY += this.motY;
        this.locZ += this.motZ;
        float f1 = MathHelper.a(this.motX * this.motX + this.motZ * this.motZ);

        this.yaw = (float) (Math.atan2(this.motX, this.motZ) * 180.0D / 3.1415927410125732D);

        for (this.pitch = (float) (Math.atan2(this.motY, (double) f1) * 180.0D / 3.1415927410125732D); this.pitch - this.lastPitch < -180.0F; this.lastPitch -= 360.0F) {
            ;
        }

        while (this.pitch - this.lastPitch >= 180.0F) {
            this.lastPitch += 360.0F;
        }

        while (this.yaw - this.lastYaw < -180.0F) {
            this.lastYaw -= 360.0F;
        }

        while (this.yaw - this.lastYaw >= 180.0F) {
            this.lastYaw += 360.0F;
        }

        this.pitch = this.lastPitch + (this.pitch - this.lastPitch) * 0.2F;
        this.yaw = this.lastYaw + (this.yaw - this.lastYaw) * 0.2F;
        float f2 = 0.99F;
        float f3 = this.e();

        if (this.az()) {
            for (int k = 0; k < 4; ++k) {
                float f4 = 0.25F;

                this.world.a("bubble", this.locX - this.motX * (double) f4, this.locY - this.motY * (double) f4, this.locZ - this.motZ * (double) f4, this.motX, this.motY, this.motZ);
            }

            f2 = 0.8F;
        }

        this.motX *= (double) f2;
        this.motY *= (double) f2;
        this.motZ *= (double) f2;
        this.motY -= (double) f3;
        this.setPosition(this.locX, this.locY, this.locZ);
    }

    protected float e() {
        return 0.03F;
    }

    protected abstract void a(MovingObjectPosition movingobjectposition);

    public void b(NBTTagCompound nbttagcompound) {
        nbttagcompound.a("xTile", (short) this.blockX);
        nbttagcompound.a("yTile", (short) this.blockY);
        nbttagcompound.a("zTile", (short) this.blockZ);
        nbttagcompound.a("inTile", (byte) this.inBlockId);
        nbttagcompound.a("shake", (byte) this.shake);
        nbttagcompound.a("inGround", (byte) (this.inGround ? 1 : 0));
    }

    public void a(NBTTagCompound nbttagcompound) {
        this.blockX = nbttagcompound.e("xTile");
        this.blockY = nbttagcompound.e("yTile");
        this.blockZ = nbttagcompound.e("zTile");
        this.inBlockId = nbttagcompound.d("inTile") & 255;
        this.shake = nbttagcompound.d("shake") & 255;
        this.inGround = nbttagcompound.d("inGround") == 1;
    }

    public void a_(EntityHuman entityhuman) {}
}