Reach Code (Minecraft 1.8.9)

// This class should be initialized in the Main class during the “FMLInitializationEvent” with
// “FMLCommonHandler.instance().bus().register(new <your reach class name>());”

//   -  D3V


package <your package>;

// import <your other class>; (if needed)

import java.util.List;

import net.minecraft.client.Minecraft;
import net.minecraft.client.entity.EntityOtherPlayerMP;
import net.minecraft.entity.Entity;
import net.minecraft.entity.EntityLivingBase;
import net.minecraft.entity.item.EntityItemFrame;
import net.minecraft.util.AxisAlignedBB;
import net.minecraft.util.ChatComponentText;
import net.minecraft.util.MovingObjectPosition;
import net.minecraft.util.Vec3;
import net.minecraftforge.client.event.MouseEvent;
import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
import net.minecraftforge.fml.common.gameevent.TickEvent.ClientTickEvent;

public class <your class name> {

    private Entity pointedEntity;
    private MovingObjectPosition moving;
    private static float theReach = 3.0F;

    @SubscribeEvent
    public void onMouse(MouseEvent e) {
        try {
            if (moving != null && e.button == 0 && e.buttonstate) {
                Minecraft.getMinecraft().objectMouseOver = moving;
            }
        } catch (Exception er) {
            er.printStackTrace();
        }
    }

    @SubscribeEvent
    public void onClientTick(ClientTickEvent e) {
        if (Minecraft.getMinecraft().theWorld != null) {
            // theReach = <your other class>.theReach; (if you want to register reach with a command)
            getMouseOver(1.0F);
        }
    }

    private void getMouseOver(float partialTicks) {
          if (Minecraft.getMinecraft().getRenderViewEntity() != null && Minecraft.getMinecraft().theWorld != null) {
             Minecraft.getMinecraft().pointedEntity = null;
             double d0 = (double)theReach;
             moving = Minecraft.getMinecraft().getRenderViewEntity().rayTrace(d0, partialTicks);
             double d1 = d0;
             Vec3 vec3 = Minecraft.getMinecraft().getRenderViewEntity().getPositionEyes(partialTicks);
             if (moving != null) {
                d1 = moving.hitVec.distanceTo(vec3);
             }

             Vec3 vec31 = Minecraft.getMinecraft().getRenderViewEntity().getLook(partialTicks);
             Vec3 vec32 = vec3.addVector(vec31.xCoord * d0, vec31.yCoord * d0, vec31.zCoord * d0);
             pointedEntity = null;
             Vec3 vec33 = null;
             float f1 = 1.0F;
             List list = Minecraft.getMinecraft().theWorld.getEntitiesWithinAABBExcludingEntity(Minecraft.getMinecraft().getRenderViewEntity(), Minecraft.getMinecraft().getRenderViewEntity().getEntityBoundingBox().addCoord(vec31.xCoord * d0, vec31.yCoord * d0, vec31.zCoord * d0).expand((double)f1, (double)f1, (double)f1));
             double d2 = d1;

             for(int i = 0; i < list.size(); ++i) {
                Entity entity = (Entity)list.get(i);
                if (entity.canBeCollidedWith()) {
                   float f2 = 0.13F;
                   AxisAlignedBB axisalignedbb = entity.getEntityBoundingBox().expand((double)f2, (double)f2, (double)f2);
                   MovingObjectPosition movingobjectposition = axisalignedbb.calculateIntercept(vec3, vec32);
                   if (axisalignedbb.isVecInside(vec3)) {
                      if (0.0D < d2 || d2 == 0.0D) {
                         pointedEntity = entity;
                         vec33 = movingobjectposition == null ? vec3 : movingobjectposition.hitVec;
                         d2 = 0.0D;
                      }
                   } else if (movingobjectposition != null) {
                      double d3 = vec3.distanceTo(movingobjectposition.hitVec);
                      if (d3 < d2 || d2 == 0.0D) {
                         if (entity == Minecraft.getMinecraft().getRenderViewEntity().ridingEntity && !entity.canRiderInteract()) {
                            if (d2 == 0.0D) {
                               pointedEntity = entity;
                               vec33 = movingobjectposition.hitVec;
                            }
                         } else {
                            pointedEntity = entity;
                            vec33 = movingobjectposition.hitVec;
                            d2 = d3;
                         }
                      }
                   }
                }
             }

             if (pointedEntity != null && (d2 < d1 || moving == null)) {
                moving = new MovingObjectPosition(pointedEntity, vec33);
                if (pointedEntity instanceof EntityLivingBase || pointedEntity instanceof EntityItemFrame) {
                   Minecraft.getMinecraft().pointedEntity = pointedEntity;
                }
             }
          }

       }

}


// Link: http://bit.ly/reachmodcode
// D3V: https://www.youtube.com/channel/UCaZSjarAwZqW4yTEC5Cq9aw