MathUtils.java

/*
 * Copyright 2014 Flavio Faria
 *
 * 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.marshalchen.common.uimodule.kenburnsview;

import android.graphics.RectF;

/**
 * Helper class to perform math computations.
 */
public final class MathUtils {

    /**
     * Truncates a float number {@code f} to {@code decimalPlaces}.
     * @param f the number to be truncated.
     * @param decimalPlaces the amount of decimals that {@code f}
     * will be truncated to.
     * @return a truncated representation of {@code f}.
     */
    protected static float truncate(float f, int decimalPlaces) {
        float decimalShift = (float) Math.pow(10, decimalPlaces);
        return Math.round(f * decimalShift) / decimalShift;
    }


    /**
     * Computes the aspect ratio of a given rect.
     * @param rect the rect to have its aspect ratio computed.
     * @return the rect aspect ratio.
     */
    protected static float getRectRatio(RectF rect) {
        return rect.width() / rect.height();
    }
}