001package net.minecraft.world.gen.structure;
002
003import java.util.HashMap;
004import java.util.Iterator;
005import java.util.List;
006import java.util.Map;
007import java.util.Random;
008import net.minecraft.crash.CrashReport;
009import net.minecraft.crash.CrashReportCategory;
010import net.minecraft.util.ReportedException;
011import net.minecraft.world.ChunkCoordIntPair;
012import net.minecraft.world.ChunkPosition;
013import net.minecraft.world.World;
014import net.minecraft.world.gen.MapGenBase;
015
016public abstract class MapGenStructure extends MapGenBase
017{
018    /**
019     * Used to store a list of all structures that have been recursively generated. Used so that during recursive
020     * generation, the structure generator can avoid generating structures that intersect ones that have already been
021     * placed.
022     */
023    protected Map structureMap = new HashMap();
024
025    /**
026     * Recursively called by generate() (generate) and optionally by itself.
027     */
028    protected void recursiveGenerate(World par1World, int par2, int par3, int par4, int par5, byte[] par6ArrayOfByte)
029    {
030        if (!this.structureMap.containsKey(Long.valueOf(ChunkCoordIntPair.chunkXZ2Int(par2, par3))))
031        {
032            this.rand.nextInt();
033
034            try
035            {
036                if (this.canSpawnStructureAtCoords(par2, par3))
037                {
038                    StructureStart structurestart = this.getStructureStart(par2, par3);
039                    this.structureMap.put(Long.valueOf(ChunkCoordIntPair.chunkXZ2Int(par2, par3)), structurestart);
040                }
041            }
042            catch (Throwable throwable)
043            {
044                CrashReport crashreport = CrashReport.makeCrashReport(throwable, "Exception preparing structure feature");
045                CrashReportCategory crashreportcategory = crashreport.makeCategory("Feature being prepared");
046                crashreportcategory.addCrashSectionCallable("Is feature chunk", new CallableIsFeatureChunk(this, par2, par3));
047                crashreportcategory.addCrashSection("Chunk location", String.format("%d,%d", new Object[] {Integer.valueOf(par2), Integer.valueOf(par3)}));
048                crashreportcategory.addCrashSectionCallable("Chunk pos hash", new CallableChunkPosHash(this, par2, par3));
049                crashreportcategory.addCrashSectionCallable("Structure type", new CallableStructureType(this));
050                throw new ReportedException(crashreport);
051            }
052        }
053    }
054
055    /**
056     * Generates structures in specified chunk next to existing structures. Does *not* generate StructureStarts.
057     */
058    public boolean generateStructuresInChunk(World par1World, Random par2Random, int par3, int par4)
059    {
060        int k = (par3 << 4) + 8;
061        int l = (par4 << 4) + 8;
062        boolean flag = false;
063        Iterator iterator = this.structureMap.values().iterator();
064
065        while (iterator.hasNext())
066        {
067            StructureStart structurestart = (StructureStart)iterator.next();
068
069            if (structurestart.isSizeableStructure() && structurestart.getBoundingBox().intersectsWith(k, l, k + 15, l + 15))
070            {
071                structurestart.generateStructure(par1World, par2Random, new StructureBoundingBox(k, l, k + 15, l + 15));
072                flag = true;
073            }
074        }
075
076        return flag;
077    }
078
079    /**
080     * Returns true if the structure generator has generated a structure located at the given position tuple.
081     */
082    public boolean hasStructureAt(int par1, int par2, int par3)
083    {
084        Iterator iterator = this.structureMap.values().iterator();
085
086        while (iterator.hasNext())
087        {
088            StructureStart structurestart = (StructureStart)iterator.next();
089
090            if (structurestart.isSizeableStructure() && structurestart.getBoundingBox().intersectsWith(par1, par3, par1, par3))
091            {
092                Iterator iterator1 = structurestart.getComponents().iterator();
093
094                while (iterator1.hasNext())
095                {
096                    StructureComponent structurecomponent = (StructureComponent)iterator1.next();
097
098                    if (structurecomponent.getBoundingBox().isVecInside(par1, par2, par3))
099                    {
100                        return true;
101                    }
102                }
103            }
104        }
105
106        return false;
107    }
108
109    public ChunkPosition getNearestInstance(World par1World, int par2, int par3, int par4)
110    {
111        this.worldObj = par1World;
112        this.rand.setSeed(par1World.getSeed());
113        long l = this.rand.nextLong();
114        long i1 = this.rand.nextLong();
115        long j1 = (long)(par2 >> 4) * l;
116        long k1 = (long)(par4 >> 4) * i1;
117        this.rand.setSeed(j1 ^ k1 ^ par1World.getSeed());
118        this.recursiveGenerate(par1World, par2 >> 4, par4 >> 4, 0, 0, (byte[])null);
119        double d0 = Double.MAX_VALUE;
120        ChunkPosition chunkposition = null;
121        Iterator iterator = this.structureMap.values().iterator();
122        ChunkPosition chunkposition1;
123        int l1;
124        int i2;
125        double d1;
126        int j2;
127
128        while (iterator.hasNext())
129        {
130            StructureStart structurestart = (StructureStart)iterator.next();
131
132            if (structurestart.isSizeableStructure())
133            {
134                StructureComponent structurecomponent = (StructureComponent)structurestart.getComponents().get(0);
135                chunkposition1 = structurecomponent.getCenter();
136                i2 = chunkposition1.x - par2;
137                l1 = chunkposition1.y - par3;
138                j2 = chunkposition1.z - par4;
139                d1 = (double)(i2 + i2 * l1 * l1 + j2 * j2);
140
141                if (d1 < d0)
142                {
143                    d0 = d1;
144                    chunkposition = chunkposition1;
145                }
146            }
147        }
148
149        if (chunkposition != null)
150        {
151            return chunkposition;
152        }
153        else
154        {
155            List list = this.getCoordList();
156
157            if (list != null)
158            {
159                ChunkPosition chunkposition2 = null;
160                Iterator iterator1 = list.iterator();
161
162                while (iterator1.hasNext())
163                {
164                    chunkposition1 = (ChunkPosition)iterator1.next();
165                    i2 = chunkposition1.x - par2;
166                    l1 = chunkposition1.y - par3;
167                    j2 = chunkposition1.z - par4;
168                    d1 = (double)(i2 + i2 * l1 * l1 + j2 * j2);
169
170                    if (d1 < d0)
171                    {
172                        d0 = d1;
173                        chunkposition2 = chunkposition1;
174                    }
175                }
176
177                return chunkposition2;
178            }
179            else
180            {
181                return null;
182            }
183        }
184    }
185
186    /**
187     * Returns a list of other locations at which the structure generation has been run, or null if not relevant to this
188     * structure generator.
189     */
190    protected List getCoordList()
191    {
192        return null;
193    }
194
195    protected abstract boolean canSpawnStructureAtCoords(int i, int j);
196
197    protected abstract StructureStart getStructureStart(int i, int j);
198}