001    package net.minecraft.entity.ai;
002    
003    import net.minecraft.entity.Entity;
004    import net.minecraft.entity.EntityLiving;
005    import net.minecraft.util.MathHelper;
006    
007    public class EntityLookHelper
008    {
009        private EntityLiving entity;
010    
011        /**
012         * The amount of change that is made each update for an entity facing a direction.
013         */
014        private float deltaLookYaw;
015    
016        /**
017         * The amount of change that is made each update for an entity facing a direction.
018         */
019        private float deltaLookPitch;
020    
021        /** Whether or not the entity is trying to look at something. */
022        private boolean isLooking = false;
023        private double posX;
024        private double posY;
025        private double posZ;
026    
027        public EntityLookHelper(EntityLiving par1EntityLiving)
028        {
029            this.entity = par1EntityLiving;
030        }
031    
032        /**
033         * Sets position to look at using entity
034         */
035        public void setLookPositionWithEntity(Entity par1Entity, float par2, float par3)
036        {
037            this.posX = par1Entity.posX;
038    
039            if (par1Entity instanceof EntityLiving)
040            {
041                this.posY = par1Entity.posY + (double)par1Entity.getEyeHeight();
042            }
043            else
044            {
045                this.posY = (par1Entity.boundingBox.minY + par1Entity.boundingBox.maxY) / 2.0D;
046            }
047    
048            this.posZ = par1Entity.posZ;
049            this.deltaLookYaw = par2;
050            this.deltaLookPitch = par3;
051            this.isLooking = true;
052        }
053    
054        /**
055         * Sets position to look at
056         */
057        public void setLookPosition(double par1, double par3, double par5, float par7, float par8)
058        {
059            this.posX = par1;
060            this.posY = par3;
061            this.posZ = par5;
062            this.deltaLookYaw = par7;
063            this.deltaLookPitch = par8;
064            this.isLooking = true;
065        }
066    
067        /**
068         * Updates look
069         */
070        public void onUpdateLook()
071        {
072            this.entity.rotationPitch = 0.0F;
073    
074            if (this.isLooking)
075            {
076                this.isLooking = false;
077                double var1 = this.posX - this.entity.posX;
078                double var3 = this.posY - (this.entity.posY + (double)this.entity.getEyeHeight());
079                double var5 = this.posZ - this.entity.posZ;
080                double var7 = (double)MathHelper.sqrt_double(var1 * var1 + var5 * var5);
081                float var9 = (float)(Math.atan2(var5, var1) * 180.0D / Math.PI) - 90.0F;
082                float var10 = (float)(-(Math.atan2(var3, var7) * 180.0D / Math.PI));
083                this.entity.rotationPitch = this.updateRotation(this.entity.rotationPitch, var10, this.deltaLookPitch);
084                this.entity.rotationYawHead = this.updateRotation(this.entity.rotationYawHead, var9, this.deltaLookYaw);
085            }
086            else
087            {
088                this.entity.rotationYawHead = this.updateRotation(this.entity.rotationYawHead, this.entity.renderYawOffset, 10.0F);
089            }
090    
091            float var11 = MathHelper.wrapAngleTo180_float(this.entity.rotationYawHead - this.entity.renderYawOffset);
092    
093            if (!this.entity.getNavigator().noPath())
094            {
095                if (var11 < -75.0F)
096                {
097                    this.entity.rotationYawHead = this.entity.renderYawOffset - 75.0F;
098                }
099    
100                if (var11 > 75.0F)
101                {
102                    this.entity.rotationYawHead = this.entity.renderYawOffset + 75.0F;
103                }
104            }
105        }
106    
107        private float updateRotation(float par1, float par2, float par3)
108        {
109            float var4 = MathHelper.wrapAngleTo180_float(par2 - par1);
110    
111            if (var4 > par3)
112            {
113                var4 = par3;
114            }
115    
116            if (var4 < -par3)
117            {
118                var4 = -par3;
119            }
120    
121            return par1 + var4;
122        }
123    }