package com.example.cici.utils;

import android.graphics.Bitmap;

/**
 * Created by Andream on 2017/10/19.
 * 图片裁剪正方形类
 */

public class CircleTransform {
    /**
     * @param bitmap      原图
     * @param edgeLength  希望得到的正方形部分的边长
     * @return  缩放截取正中部分后的位图。
     */
    public static Bitmap centerSquareScaleBitmap(Bitmap bitmap, int edgeLength)
    {
        if(null == bitmap || edgeLength <= 0)
        {
            return  null;
        }

        Bitmap result = bitmap;
        int widthOrg = bitmap.getWidth();
        int heightOrg = bitmap.getHeight();

        if(widthOrg > edgeLength && heightOrg > edgeLength)
        {
            //压缩到一个最小长度是edgeLength的bitmap
            int longerEdge = (int)(edgeLength * Math.max(widthOrg, heightOrg) / Math.min(widthOrg, heightOrg));
            int scaledWidth = widthOrg > heightOrg ? longerEdge : edgeLength;
            int scaledHeight = widthOrg > heightOrg ? edgeLength : longerEdge;
            Bitmap scaledBitmap;

            try{
                scaledBitmap = Bitmap.createScaledBitmap(bitmap, scaledWidth, scaledHeight, true);
            }
            catch(Exception e){
                return null;
            }

            //从图中截取正中间的正方形部分。
            int xTopLeft = (scaledWidth - edgeLength) / 2;
            int yTopLeft = (scaledHeight - edgeLength) / 2;

            try{
                result = Bitmap.createBitmap(scaledBitmap, xTopLeft, yTopLeft, edgeLength, edgeLength);
                scaledBitmap.recycle();
            }
            catch(Exception e){
                return null;
            }
        }

        return result;
    }
}
