MathUtils.java

/*
 * Copyright 2012 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.zxing.common.detector;

public final class MathUtils {

	private MathUtils() {
	}

	/**
	 * Ends up being a bit faster than {@link Math#round(float)}. This merely
	 * rounds its argument to the nearest int, where x.5 rounds up to x+1.
	 * Semantics of this shortcut differ slightly from {@link Math#round(float)}
	 * in that half rounds down for negative values. -2.5 rounds to -3, not -2.
	 * For purposes here it makes no difference.
	 * 
	 * @param d
	 *            real value to round
	 * @return nearest {@code int}
	 */
	public static int round(float d) {
		return (int) (d + (d < 0.0f ? -0.5f : 0.5f));
	}

	public static float distance(float aX, float aY, float bX, float bY) {
		float xDiff = aX - bX;
		float yDiff = aY - bY;
		return (float) Math.sqrt(xDiff * xDiff + yDiff * yDiff);
	}

	public static float distance(int aX, int aY, int bX, int bY) {
		int xDiff = aX - bX;
		int yDiff = aY - bY;
		return (float) Math.sqrt(xDiff * xDiff + yDiff * yDiff);
	}

}