com.xiaoleilu.hutool.captcha.ShearCaptcha Maven / Gradle / Ivy

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package com.xiaoleilu.hutool.captcha;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;

import com.xiaoleilu.hutool.util.ImageUtil;
import com.xiaoleilu.hutool.util.RandomUtil;

/**
 * 扭曲干扰验证码
 * 
 * @author looly
 * @since 3.2.3
 *
 */
public class ShearCaptcha extends AbstractCaptcha {
	private static final long serialVersionUID = -7096627300356535494L;

	/**
	 * 构造
	 * 
	 * @param width 图片宽
	 * @param height 图片高
	 */
	public ShearCaptcha(int width, int height) {
		this(width, height, 5);
	}

	/**
	 * 构造
	 * 
	 * @param width 图片宽
	 * @param height 图片高
	 * @param codeCount 字符个数
	 */
	public ShearCaptcha(int width, int height, int codeCount) {
		this(width, height, codeCount, 4);
	}

	/**
	 * 构造
	 * 
	 * @param width 图片宽
	 * @param height 图片高
	 * @param codeCount 字符个数
	 * @param thickness 干扰线宽度
	 */
	public ShearCaptcha(int width, int height, int codeCount, int thickness) {
		super(width, height, codeCount, thickness);
	}

	@Override
	public void createImage(String code) {
		this.image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		final Graphics2D g = ImageUtil.createGraphics(this.image, Color.WHITE);

		// 画字符串
		g.setColor(Color.black);
		g.setFont(font);
		int charWidth = width / (codeCount + 2);
		for (int i = 0; i < codeCount; i++) {
			// 产生随机的颜色值，让输出的每个字符的颜色值都将不同。
			g.setColor(ImageUtil.randomColor());
			g.drawString(String.valueOf(code.charAt(i)), (i + 1) * charWidth, height - 4);
		}
//		g.drawString(code, 1, height - 4);

		shear(g, width, height, Color.white);
		drawThickLine(g, 0, RandomUtil.randomInt(height) + 1, width, RandomUtil.randomInt(height) + 1, this.interfereCount, ImageUtil.randomColor());
	}

	// ----------------------------------------------------------------------------------------------------- Private method start

	/**
	 * 扭曲
	 * 
	 * @param g {@link Graphics}
	 * @param w1 w1
	 * @param h1 h1
	 * @param color 颜色
	 */
	private void shear(Graphics g, int w1, int h1, Color color) {

		shearX(g, w1, h1, color);
		shearY(g, w1, h1, color);
	}

	/**
	 * Y坐标扭曲
	 * 
	 * @param g {@link Graphics}
	 * @param w1 w1
	 * @param h1 h1
	 * @param color 颜色
	 */
	private void shearX(Graphics g, int w1, int h1, Color color) {

		int period = RandomUtil.randomInt(2);

		boolean borderGap = true;
		int frames = 1;
		int phase = RandomUtil.randomInt(2);

		for (int i = 0; i < h1; i++) {
			double d = (double) (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);
			g.copyArea(0, i, w1, 1, (int) d, 0);
			if (borderGap) {
				g.setColor(color);
				g.drawLine((int) d, i, 0, i);
				g.drawLine((int) d + w1, i, w1, i);
			}
		}

	}

	/**
	 * X坐标扭曲
	 * 
	 * @param g {@link Graphics}
	 * @param w1 w1
	 * @param h1 h1
	 * @param color 颜色
	 */
	private void shearY(Graphics g, int w1, int h1, Color color) {

		int period = RandomUtil.randomInt(40) + 10; // 50;

		boolean borderGap = true;
		int frames = 20;
		int phase = 7;
		for (int i = 0; i < w1; i++) {
			double d = (double) (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * (double) phase) / (double) frames);
			g.copyArea(i, 0, 1, h1, 0, (int) d);
			if (borderGap) {
				g.setColor(color);
				g.drawLine(i, (int) d, i, 0);
				g.drawLine(i, (int) d + h1, i, h1);
			}

		}

	}

	/**
	 * 干扰线
	 * 
	 * @param g {@link Graphics}
	 * @param x1x1
	 * @param y1 y1
	 * @param x2 x2
	 * @param y2 y2
	 * @param thickness 粗细
	 * @param c 颜色
	 */
	private void drawThickLine(Graphics g, int x1, int y1, int x2, int y2, int thickness, Color c) {

		// The thick line is in fact a filled polygon
		g.setColor(c);
		int dX = x2 - x1;
		int dY = y2 - y1;
		// line length
		double lineLength = Math.sqrt(dX * dX + dY * dY);

		double scale = (double) (thickness) / (2 * lineLength);

		// The x and y increments from an endpoint needed to create a
		// rectangle...
		double ddx = -scale * (double) dY;
		double ddy = scale * (double) dX;
		ddx += (ddx > 0) ? 0.5 : -0.5;
		ddy += (ddy > 0) ? 0.5 : -0.5;
		int dx = (int) ddx;
		int dy = (int) ddy;

		// Now we can compute the corner points...
		int xPoints[] = new int[4];
		int yPoints[] = new int[4];

		xPoints[0] = x1 + dx;
		yPoints[0] = y1 + dy;
		xPoints[1] = x1 - dx;
		yPoints[1] = y1 - dy;
		xPoints[2] = x2 - dx;
		yPoints[2] = y2 - dy;
		xPoints[3] = x2 + dx;
		yPoints[3] = y2 + dy;

		g.fillPolygon(xPoints, yPoints, 4);
	}
	// ----------------------------------------------------------------------------------------------------- Private method end
}