001    package net.minecraft.world.gen.structure;
002    
003    import java.util.HashMap;
004    import java.util.Iterator;
005    import java.util.List;
006    import java.util.Map;
007    import java.util.Random;
008    import net.minecraft.crash.CrashReport;
009    import net.minecraft.crash.CrashReportCategory;
010    import net.minecraft.util.ReportedException;
011    import net.minecraft.world.ChunkCoordIntPair;
012    import net.minecraft.world.ChunkPosition;
013    import net.minecraft.world.World;
014    import net.minecraft.world.gen.MapGenBase;
015    
016    public 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 var7 = this.getStructureStart(par2, par3);
039                        this.structureMap.put(Long.valueOf(ChunkCoordIntPair.chunkXZ2Int(par2, par3)), var7);
040                    }
041                }
042                catch (Throwable var10)
043                {
044                    CrashReport var8 = CrashReport.makeCrashReport(var10, "Exception preparing structure feature");
045                    CrashReportCategory var9 = var8.makeCategory("Feature being prepared");
046                    var9.addCrashSectionCallable("Is feature chunk", new CallableIsFeatureChunk(this, par2, par3));
047                    var9.addCrashSection("Chunk location", String.format("%d,%d", new Object[] {Integer.valueOf(par2), Integer.valueOf(par3)}));
048                    var9.addCrashSectionCallable("Chunk pos hash", new CallableChunkPosHash(this, par2, par3));
049                    var9.addCrashSectionCallable("Structure type", new CallableStructureType(this));
050                    throw new ReportedException(var8);
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 var5 = (par3 << 4) + 8;
061            int var6 = (par4 << 4) + 8;
062            boolean var7 = false;
063            Iterator var8 = this.structureMap.values().iterator();
064    
065            while (var8.hasNext())
066            {
067                StructureStart var9 = (StructureStart)var8.next();
068    
069                if (var9.isSizeableStructure() && var9.getBoundingBox().intersectsWith(var5, var6, var5 + 15, var6 + 15))
070                {
071                    var9.generateStructure(par1World, par2Random, new StructureBoundingBox(var5, var6, var5 + 15, var6 + 15));
072                    var7 = true;
073                }
074            }
075    
076            return var7;
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 var4 = this.structureMap.values().iterator();
085    
086            while (var4.hasNext())
087            {
088                StructureStart var5 = (StructureStart)var4.next();
089    
090                if (var5.isSizeableStructure() && var5.getBoundingBox().intersectsWith(par1, par3, par1, par3))
091                {
092                    Iterator var6 = var5.getComponents().iterator();
093    
094                    while (var6.hasNext())
095                    {
096                        StructureComponent var7 = (StructureComponent)var6.next();
097    
098                        if (var7.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 var5 = this.rand.nextLong();
114            long var7 = this.rand.nextLong();
115            long var9 = (long)(par2 >> 4) * var5;
116            long var11 = (long)(par4 >> 4) * var7;
117            this.rand.setSeed(var9 ^ var11 ^ par1World.getSeed());
118            this.recursiveGenerate(par1World, par2 >> 4, par4 >> 4, 0, 0, (byte[])null);
119            double var13 = Double.MAX_VALUE;
120            ChunkPosition var15 = null;
121            Iterator var16 = this.structureMap.values().iterator();
122            ChunkPosition var19;
123            int var21;
124            int var20;
125            double var23;
126            int var22;
127    
128            while (var16.hasNext())
129            {
130                StructureStart var17 = (StructureStart)var16.next();
131    
132                if (var17.isSizeableStructure())
133                {
134                    StructureComponent var18 = (StructureComponent)var17.getComponents().get(0);
135                    var19 = var18.getCenter();
136                    var20 = var19.x - par2;
137                    var21 = var19.y - par3;
138                    var22 = var19.z - par4;
139                    var23 = (double)(var20 + var20 * var21 * var21 + var22 * var22);
140    
141                    if (var23 < var13)
142                    {
143                        var13 = var23;
144                        var15 = var19;
145                    }
146                }
147            }
148    
149            if (var15 != null)
150            {
151                return var15;
152            }
153            else
154            {
155                List var25 = this.getCoordList();
156    
157                if (var25 != null)
158                {
159                    ChunkPosition var26 = null;
160                    Iterator var27 = var25.iterator();
161    
162                    while (var27.hasNext())
163                    {
164                        var19 = (ChunkPosition)var27.next();
165                        var20 = var19.x - par2;
166                        var21 = var19.y - par3;
167                        var22 = var19.z - par4;
168                        var23 = (double)(var20 + var20 * var21 * var21 + var22 * var22);
169    
170                        if (var23 < var13)
171                        {
172                            var13 = var23;
173                            var26 = var19;
174                        }
175                    }
176    
177                    return var26;
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 var1, int var2);
196    
197        protected abstract StructureStart getStructureStart(int var1, int var2);
198    }