ArrayUtils.java

/*
 * Copyright 2013 Hannes Janetzek
 *
 * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
 *
 * This program is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.oscim.utils;

public class ArrayUtils {

	public static <T> void reverse(T[] data) {
		reverse(data, 0, data.length);
	}

	public static <T> void reverse(T[] data, int left, int right) {
		right--;

		while (left < right) {
			T tmp = data[left];
			data[left] = data[right];
			data[right] = tmp;

			left++;
			right--;
		}
	}

	public static void reverse(short[] data, int left, int right, int stride) {
		right -= stride;

		while (left < right) {
			for (int i = 0; i < stride; i++) {
				short tmp = data[left + i];
				data[left + i] = data[right + i];
				data[right + i] = tmp;
			}
			left += stride;
			right -= stride;
		}
	}

	public static void reverse(byte[] data, int left, int right) {
		right -= 1;

		while (left < right) {
			byte tmp = data[left];
			data[left] = data[right];
			data[right] = tmp;

			left++;
			right--;
		}
	}

	public static double parseNumber(char[] str, int pos, int end) {

		boolean neg = false;
		if (str[pos] == '-') {
			neg = true;
			pos++;
		}

		double val = 0;
		int pre = 0;
		char c = 0;

		for (; pos < end; pos++, pre++) {
			c = str[pos];
			if (c < '0' || c > '9') {
				if (pre == 0)
					throw new NumberFormatException("s " + c);

				break;
			}
			val = val * 10 + (int) (c - '0');
		}

		if (pre == 0)
			throw new NumberFormatException();

		if (c == '.') {
			float div = 10;
			for (pos++; pos < end; pos++) {
				c = str[pos];
				if (c < '0' || c > '9')
					break;
				val = val + ((int) (c - '0')) / div;
				div *= 10;
			}
		}

		if (c == 'e' || c == 'E') {
			// advance 'e'
			pos++;

			// check direction
			int dir = 1;
			if (str[pos] == '-') {
				dir = -1;
				pos++;
			}
			// skip leading zeros
			for (; pos < end; pos++)
				if (str[pos] != '0')
					break;

			int shift = 0;
			for (pre = 0; pos < end; pos++, pre++) {
				c = str[pos];
				if (c < '0' || c > '9') {
					// nothing after 'e'
					if (pre == 0)
						throw new NumberFormatException("e " + c);
					break;
				}
				shift = shift * 10 + (int) (c - '0');
			}

			// guess it's ok for sane values of E
			if (dir > 0) {
				while (shift-- > 0)
					val *= 10;
			} else {
				while (shift-- > 0)
					val /= 10;
			}
		}

		return neg ? -val : val;
	}

	public static boolean withinRange(float[] vec, float min, float max) {
		for (int i = 0, n = vec.length; i < n; i++) {
			float v = vec[i];
			if (v < min || v > max)
				return false;
		}
		return true;
	}

	/**
	 * Set bbox array to:
	 * xmin, ymin,
	 * xmin, ymax,
	 * xmax, ymax,
	 * xmax, ymin,
	 */
	public static void setBox2D(float[] bbox, float xmin, float ymin, float xmax, float ymax) {
		bbox[0] = bbox[2] = xmin;
		bbox[4] = bbox[6] = xmax;
		bbox[1] = bbox[7] = ymin;
		bbox[3] = bbox[5] = ymax;
	}
}