CubicStructureGenerator.java

/*
 *  This file is part of Cubic Chunks Mod, licensed under the MIT License (MIT).
 *
 *  Copyright (c) 2015 contributors
 *
 *  Permission is hereby granted, free of charge, to any person obtaining a copy
 *  of this software and associated documentation files (the "Software"), to deal
 *  in the Software without restriction, including without limitation the rights
 *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *  copies of the Software, and to permit persons to whom the Software is
 *  furnished to do so, subject to the following conditions:
 *
 *  The above copyright notice and this permission notice shall be included in
 *  all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *  THE SOFTWARE.
 */
package cubicchunks.worldgen.generator.custom.structures;

import java.util.Random;

import cubicchunks.util.CubePos;
import cubicchunks.world.ICubicWorld;
import cubicchunks.worldgen.generator.ICubePrimer;

/**
 * Basic structure generator for Cubic Chunks.
 * <p>
 * The basic idea is to loop over all cubes within some radius (max structure size) and figure out which parts of
 * structures starting there intersect currently generated cube.
 */
public abstract class CubicStructureGenerator {

	/** The number of Chunks to gen-check in any given direction. */
	protected int range = 8;

	/** The RNG used by the MapGen classes. */
	protected Random rand = new Random();

	/** This world object. */
	protected ICubicWorld world;

	/**
	 * Generates structures in given cube.
	 *
	 * @param world the world that the structure is generated in
	 * @param cube the block buffer to be filled with blocks (Cube)
	 * @param cubePos position of the cube to generate structures in
	 */
	public void generate(ICubicWorld world, ICubePrimer cube, CubePos cubePos) {

		//TODO: maybe skip some of this stuff if the cube is empty? (would need to use hints)

		int radius = this.range;
		this.world = world;
		this.rand.setSeed(world.getSeed());
		//used to randomize contribution of each coordinate to the cube seed
		//without these swapping x/y/z coordinates would result in the same seed
		//so structures would generate symmetrically
		long randX = this.rand.nextLong();
		long randY = this.rand.nextLong();
		long randZ = this.rand.nextLong();

		int cubeX = cubePos.getX();
		int cubeY = cubePos.getY();
		int cubeZ = cubePos.getZ();

		//x/y/zOrigin is location of the structure "center", and cubeX/Y/Z is the currently generated cube
		for (int xOrigin = cubeX - radius; xOrigin <= cubeX + radius; ++xOrigin) {
			for (int yOrigin = cubeY - radius; yOrigin <= cubeY + radius; ++yOrigin) {
				for (int zOrigin = cubeZ - radius; zOrigin <= cubeZ + radius; ++zOrigin) {
					long randX_mul = xOrigin*randX;
					long randY_mul = yOrigin*randY;
					long randZ_mul = zOrigin*randZ;
					this.rand.setSeed(randX_mul ^ randY_mul ^ randZ_mul ^ world.getSeed());
					this.generate(world, cube, xOrigin, yOrigin, zOrigin, cubePos);
				}
			}

		}
	}

	/**
	 * Generates blocks in a given cube for a structure that starts at given origin position.
	 *
	 * @param world the world the structure is generated in
	 * @param cube the block buffer to be filled with blocks (Cube)
	 * @param structureX x coordinate of the starting position of currently generated structure
	 * @param structureY y coordinate of the starting position of currently generated structure
	 * @param structureZ z coordinate of the starting position of currently generated structure
	 * @param generatedCubePos position of the cube to fill with blocks
	 */
	protected abstract void generate(ICubicWorld world, ICubePrimer cube,
	                                 int structureX, int structureY, int structureZ,
	                                 CubePos generatedCubePos);
}