001    package net.minecraft.src;
002    
003    import java.util.Random;
004    
005    public class BlockSand extends Block
006    {
007        /** Do blocks fall instantly to where they stop or do they fall over time */
008        public static boolean fallInstantly = false;
009    
010        public BlockSand(int par1, int par2)
011        {
012            super(par1, par2, Material.sand);
013            this.setCreativeTab(CreativeTabs.tabBlock);
014        }
015    
016        /**
017         * Called whenever the block is added into the world. Args: world, x, y, z
018         */
019        public void onBlockAdded(World par1World, int par2, int par3, int par4)
020        {
021            par1World.scheduleBlockUpdate(par2, par3, par4, this.blockID, this.tickRate());
022        }
023    
024        /**
025         * Lets the block know when one of its neighbor changes. Doesn't know which neighbor changed (coordinates passed are
026         * their own) Args: x, y, z, neighbor blockID
027         */
028        public void onNeighborBlockChange(World par1World, int par2, int par3, int par4, int par5)
029        {
030            par1World.scheduleBlockUpdate(par2, par3, par4, this.blockID, this.tickRate());
031        }
032    
033        /**
034         * Ticks the block if it's been scheduled
035         */
036        public void updateTick(World par1World, int par2, int par3, int par4, Random par5Random)
037        {
038            if (!par1World.isRemote)
039            {
040                this.tryToFall(par1World, par2, par3, par4);
041            }
042        }
043    
044        /**
045         * If there is space to fall below will start this block falling
046         */
047        private void tryToFall(World par1World, int par2, int par3, int par4)
048        {
049            if (canFallBelow(par1World, par2, par3 - 1, par4) && par3 >= 0)
050            {
051                byte var8 = 32;
052    
053                if (!fallInstantly && par1World.checkChunksExist(par2 - var8, par3 - var8, par4 - var8, par2 + var8, par3 + var8, par4 + var8))
054                {
055                    if (!par1World.isRemote)
056                    {
057                        EntityFallingSand var9 = new EntityFallingSand(par1World, (double)((float)par2 + 0.5F), (double)((float)par3 + 0.5F), (double)((float)par4 + 0.5F), this.blockID);
058                        par1World.spawnEntityInWorld(var9);
059                    }
060                }
061                else
062                {
063                    par1World.setBlockWithNotify(par2, par3, par4, 0);
064    
065                    while (canFallBelow(par1World, par2, par3 - 1, par4) && par3 > 0)
066                    {
067                        --par3;
068                    }
069    
070                    if (par3 > 0)
071                    {
072                        par1World.setBlockWithNotify(par2, par3, par4, this.blockID);
073                    }
074                }
075            }
076        }
077    
078        /**
079         * How many world ticks before ticking
080         */
081        public int tickRate()
082        {
083            return 3;
084        }
085    
086        /**
087         * Checks to see if the sand can fall into the block below it
088         */
089        public static boolean canFallBelow(World par0World, int par1, int par2, int par3)
090        {
091            int var4 = par0World.getBlockId(par1, par2, par3);
092    
093            if (var4 == 0)
094            {
095                return true;
096            }
097            else if (var4 == Block.fire.blockID)
098            {
099                return true;
100            }
101            else
102            {
103                Material var5 = Block.blocksList[var4].blockMaterial;
104                return var5 == Material.water ? true : var5 == Material.lava;
105            }
106        }
107    }