defaultnoiseimp.java

基于Java平台的、功能强大的验证码图片生成工具

/*
 * Created on Sep 15, 2005
 *
 * To change the template for this generated file go to
 * Window>Preferences>Java>Code Generation>Code and Comments
 */
package nl.captcha.obscurity.imp;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.CubicCurve2D;
import java.awt.geom.PathIterator;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import java.util.Properties;
import java.util.Random;

import nl.captcha.obscurity.NoiseProducer;
import nl.captcha.servlet.Constants;
import nl.captcha.util.Helper;

/**
 * @author Administrator
 *
 * To change the template for this generated type comment go to
 * Window>Preferences>Java>Code Generation>Code and Comments
 */
public class DefaultNoiseImp implements NoiseProducer {
	
	private Properties props = null;
	public DefaultNoiseImp(Properties props) {
		this.props = props;
	}
	
	
	public void setProperties(Properties props){
		this.props = props;
	}
	
	public  void makeNoise(BufferedImage image, float factorOne,float factorTwo, float factorThree, float factorFour){
			//image size
			int width = image.getWidth();
			int height = image.getHeight();
        
			//the points where the line changes the stroke and direction
			Point2D[] pts = null;
			Random rand = new Random();
		
		     
        
			//the curve from where the points are taken
			CubicCurve2D cc = new CubicCurve2D.Float( 
				width*factorOne, height*rand.nextFloat(), 
				width*factorTwo, height*rand.nextFloat(), 
				width*factorThree, height*rand.nextFloat(), 
				width*factorFour, height*rand.nextFloat());

			// creates an iterator to define the boundary of the flattened curve 
			PathIterator pi = cc.getPathIterator(null, 2); 
			Point2D tmp[] = new Point2D[200]; 
			int i = 0; 
        
			// while pi is iterating the curve, adds points to tmp array 
			while ( !pi.isDone() ) { 
			  float[] coords = new float[6]; 
			  switch ( pi.currentSegment(coords) ) { 
				case PathIterator.SEG_MOVETO: 
				case PathIterator.SEG_LINETO: 
				  tmp[i] = new Point2D.Float(coords[0], coords[1]); 
				} 
			  i++; 
			  pi.next(); 
			  }
           
			pts = new Point2D[i]; 
			// copies points from tmp to pts 
			System.arraycopy(tmp,0,pts,0,i);
        
			Graphics2D graph = (Graphics2D)image.getGraphics();
			graph.setRenderingHints(new RenderingHints(
				RenderingHints.KEY_ANTIALIASING,
				RenderingHints.VALUE_ANTIALIAS_ON));
			
			Color mycol = Helper.getColor( props, Constants.SIMPLE_CAPTCHA_NOISE_COLOR,Color.black);
			
			graph.setColor(mycol);
        
			//for the maximum 3 point change the stroke and direction 
			for(i = 0; i < pts.length - 1; i++){
			  if(i < 3)
				graph.setStroke(new BasicStroke(0.9f * (4-i)));
			  graph.drawLine((int)pts[i].getX(), (int)pts[i].getY(), 
				(int)pts[i+1].getX(), (int)pts[i+1].getY());
			}
        
			graph.dispose();
        
		        	
		}

}