package org.spigotmc; import gnu.trove.set.TByteSet; import gnu.trove.set.hash.TByteHashSet; import net.minecraft.server.Block; import net.minecraft.server.BlockPosition; import net.minecraft.server.Blocks; import net.minecraft.server.World; import org.bukkit.craftbukkit.util.CraftMagicNumbers; public class AntiXray { private static final CustomTimingsHandler update = new CustomTimingsHandler( "xray - update" ); private static final CustomTimingsHandler obfuscate = new CustomTimingsHandler( "xray - obfuscate" ); /*========================================================================*/ // Used to keep track of which blocks to obfuscate private final boolean[] obfuscateBlocks = new boolean[ Short.MAX_VALUE ]; // Used to select a random replacement ore private final byte[] replacementOres; public AntiXray(SpigotWorldConfig config) { // Set all listed blocks as true to be obfuscated for ( int id : ( config.engineMode == 1 ) ? config.hiddenBlocks : config.replaceBlocks ) { obfuscateBlocks[id] = true; } // For every block TByteSet blocks = new TByteHashSet(); for ( Integer i : config.hiddenBlocks ) { Block block = Block.getById( i ); // Check it exists and is not a tile entity if ( block != null && !block.isTileEntity() ) { // Add it to the set of replacement blocks blocks.add( (byte) (int) i ); } } // Bake it to a flat array of replacements replacementOres = blocks.toArray(); } /** * Starts the timings handler, then updates all blocks within the set radius * of the given coordinate, revealing them if they are hidden ores. */ public void updateNearbyBlocks(World world, BlockPosition position) { if ( world.spigotConfig.antiXray ) { update.startTiming(); updateNearbyBlocks( world, position, 2, false ); // 2 is the radius, we shouldn't change it as that would make it exponentially slower update.stopTiming(); } } /** * Starts the timings handler, and then removes all non exposed ores from * the chunk buffer. */ public void obfuscateSync(int chunkX, int chunkY, int bitmask, byte[] buffer, World world) { if ( world.spigotConfig.antiXray ) { obfuscate.startTiming(); obfuscate( chunkX, chunkY, bitmask, buffer, world ); obfuscate.stopTiming(); } } /** * Removes all non exposed ores from the chunk buffer. */ public void obfuscate(int chunkX, int chunkY, int bitmask, byte[] buffer, World world) { // If the world is marked as obfuscated if ( world.spigotConfig.antiXray ) { // Initial radius to search around for air int initialRadius = 1; // Which block in the buffer we are looking at, anywhere from 0 to 16^4 int index = 0; // The iterator marking which random ore we should use next int randomOre = 0; // Chunk corner X and Z blocks int startX = chunkX << 4; int startZ = chunkY << 4; byte replaceWithTypeId; switch ( world.getWorld().getEnvironment() ) { case NETHER: replaceWithTypeId = (byte) CraftMagicNumbers.getId(Blocks.NETHERRACK); break; case THE_END: replaceWithTypeId = (byte) CraftMagicNumbers.getId(Blocks.END_STONE); break; default: replaceWithTypeId = (byte) CraftMagicNumbers.getId(Blocks.STONE); break; } // Chunks can have up to 16 sections for ( int i = 0; i < 16; i++ ) { // If the bitmask indicates this chunk is sent... if ( ( bitmask & 1 << i ) != 0 ) { // Work through all blocks in the chunk, y,z,x for ( int y = 0; y < 16; y++ ) { for ( int z = 0; z < 16; z++ ) { for ( int x = 0; x < 16; x++ ) { // For some reason we can get too far ahead of ourselves (concurrent modification on bulk chunks?) so if we do, just abort and move on if ( index >= buffer.length ) { index++; continue; } // Grab the block ID in the buffer. // TODO: extended IDs are not yet supported int blockId = (buffer[index << 1] & 0xFF) | ((buffer[(index << 1) + 1] & 0xFF) << 8); blockId >>>= 4; // Check if the block should be obfuscated if ( obfuscateBlocks[blockId] ) { // The world isn't loaded, bail out if ( !isLoaded( world, new BlockPosition( startX + x, ( i << 4 ) + y, startZ + z ), initialRadius ) ) { index++; continue; } // On the otherhand, if radius is 0, or the nearby blocks are all non air, we can obfuscate if ( !hasTransparentBlockAdjacent( world, new BlockPosition( startX + x, ( i << 4 ) + y, startZ + z ), initialRadius ) ) { int newId = blockId; switch ( world.spigotConfig.engineMode ) { case 1: // Replace with replacement material newId = replaceWithTypeId & 0xFF; break; case 2: // Replace with random ore. if ( randomOre >= replacementOres.length ) { randomOre = 0; } newId = replacementOres[randomOre++] & 0xFF; break; } newId <<= 4; buffer[index << 1] = (byte) (newId & 0xFF); buffer[(index << 1) + 1] = (byte) ((newId >> 8) & 0xFF); } } index++; } } } } } } } private void updateNearbyBlocks(World world, BlockPosition position, int radius, boolean updateSelf) { // If the block in question is loaded if ( world.isLoaded( position ) ) { // Get block id Block block = world.getType(position).getBlock(); // See if it needs update if ( updateSelf && obfuscateBlocks[Block.getId( block )] ) { // Send the update world.notify( position ); } // Check other blocks for updates if ( radius > 0 ) { updateNearbyBlocks( world, position.east(), radius - 1, true ); updateNearbyBlocks( world, position.west(), radius - 1, true ); updateNearbyBlocks( world, position.up(), radius - 1, true ); updateNearbyBlocks( world, position.down(), radius - 1, true ); updateNearbyBlocks( world, position.south(), radius - 1, true ); updateNearbyBlocks( world, position.north(), radius - 1, true ); } } } private static boolean isLoaded(World world, BlockPosition position, int radius) { return world.isLoaded( position ) && ( radius == 0 || ( isLoaded( world, position.east(), radius - 1 ) && isLoaded( world, position.west(), radius - 1 ) && isLoaded( world, position.up(), radius - 1 ) && isLoaded( world, position.down(), radius - 1 ) && isLoaded( world, position.south(), radius - 1 ) && isLoaded( world, position.north(), radius - 1 ) ) ); } private static boolean hasTransparentBlockAdjacent(World world, BlockPosition position, int radius) { return !isSolidBlock(world.getType(position, false).getBlock()) /* isSolidBlock */ || ( radius > 0 && ( hasTransparentBlockAdjacent( world, position.east(), radius - 1 ) || hasTransparentBlockAdjacent( world, position.west(), radius - 1 ) || hasTransparentBlockAdjacent( world, position.up(), radius - 1 ) || hasTransparentBlockAdjacent( world, position.down(), radius - 1 ) || hasTransparentBlockAdjacent( world, position.south(), radius - 1 ) || hasTransparentBlockAdjacent( world, position.north(), radius - 1 ) ) ); } private static boolean isSolidBlock(Block block) { // Mob spawners are treated as solid blocks as far as the // game is concerned for lighting and other tasks but for // rendering they can be seen through therefor we special // case them so that the antixray doesn't show the fake // blocks around them. return block.isOccluding() && block != Blocks.MOB_SPAWNER && block != Blocks.BARRIER; } }