package railo.commons.img;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GradientPaint;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;
/**
* Abstract template class for captcha generation
*/
public abstract class AbstractCaptcha {
public static final int DIFFICULTY_LOW=0;
public static final int DIFFICULTY_MEDIUM=1;
public static final int DIFFICULTY_HIGH=2;
/**
* generates a Captcha as a Buffered Image file
* @param text text for the captcha
* @param width width of the resulting image
* @param height height of the resulting image
* @param fonts list of font used for the captcha (all font are random used)
* @param useAntiAlias use anti aliasing or not
* @param fontColor color of the font
* @param fontSize size of the font
* @param difficulty difficulty of the reslting captcha
* @return captcha image
* @throws CaptchaException
*/
public BufferedImage generate(String text,int width, int height, String[] fonts, boolean useAntiAlias, Color fontColor,int fontSize, int difficulty) throws CaptchaException {
if(difficulty==DIFFICULTY_LOW) {
return generate(text, width, height, fonts, useAntiAlias, fontColor,fontSize, 0, 0, 0, 0, 0, 0,230,25);
}
if(difficulty==DIFFICULTY_MEDIUM) {
return generate(text, width, height, fonts, useAntiAlias, fontColor,fontSize, 0, 0, 5, 30, 0, 0,200,35);
}
return generate(text, width, height, fonts, useAntiAlias, fontColor,fontSize, 4, 10, 30, 60, 4, 10,170,45);
}
private BufferedImage generate(String text,int width, int height, String[] fonts, boolean useAntiAlias
, Color fontColor,int fontSize
, int minOvals, int maxOvals, int minBGLines, int maxBGLines, int minFGLines, int maxFGLines, int startColor, int shear) throws CaptchaException {
if(text==null || text.trim().length()==0)
throw new CaptchaException("missing Text");
char[] characters=text.toCharArray();
int top=height/3;
Dimension dimension = new Dimension(width, height);
int imageType = BufferedImage.TYPE_INT_RGB;
BufferedImage bufferedImage = new BufferedImage((int)dimension.getWidth(), (int)dimension.getHeight(), imageType);
Graphics2D graphics = bufferedImage.createGraphics();
// Set anti-alias setting
if(useAntiAlias)
graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
drawBackground(graphics, dimension,startColor);
// draw ovals
if(maxOvals>0 && maxOvals>minOvals) {
int to=rnd(minOvals,maxOvals);
for(int i=1;i<=to;i++) {
drawRandomOval(graphics, dimension, getRandomColor(startColor));
}
}
// Draw background lines
if(maxBGLines>0 && maxBGLines>minBGLines) {
int to=rnd(minBGLines,maxBGLines);
for(int i=1;i<=to;i++) {
drawRandomLine(graphics, dimension, getRandomColor(startColor));
}
}
if(fonts==null || fonts.length==0)
throw new CaptchaException("no font's defined");
// font
Font f;
ArrayList fontList=new ArrayList();
for(int i=0;i<fonts.length;i++){
f=getFont(fonts[i],null);
if(f!=null) fontList.add(f);
}
if(fonts.length==0)
throw new CaptchaException("defined fonts are not available on this system");
int charWidth=0;
int charHeight=0,tmp;
int space=0;
Font[] _fonts=new Font[characters.length];
for(int i=0;i<characters.length;i++) {
char c= characters[i];
_fonts[i]=createFont(fontList,fontSize,shear,i);
graphics.setFont(_fonts[i]);
charWidth+=graphics.getFontMetrics().charWidth(c);
tmp=graphics.getFontMetrics().getHeight();
if(tmp>charHeight)charHeight=tmp;
}
if(charWidth<width) {
space=(width-charWidth)/(characters.length+1);
}
else if (charWidth>width)throw new CaptchaException("the specified width for the CAPTCHA image is not big enough to fit the text. Minimum width is ["+charWidth+"]");
if (charHeight>height)throw new CaptchaException("the specified height for the CAPTCHA image is not big enough to fit the text. Minimum height is ["+charHeight+"]");
int left= space;
// Draw captcha text
for(int i=0;i<characters.length;i++) {
char c= characters[i];
// <cfset staticCollections.shuffle(definedFonts) />
graphics.setFont(_fonts[i]);
graphics.setColor(fontColor);
// Check if font can display current character --->
/*<cfloop condition="NOT graphics.getFont().canDisplay(char)">
<cfset setFont(graphics, definedFonts) />
</cfloop>*/
// Compute the top character position --->
top = rnd(graphics.getFontMetrics().getAscent(), height - (height - graphics.getFontMetrics().getHeight()) / 2);
// Draw character text
graphics.drawString(String.valueOf(c),left,top);
// Compute the next character lef tposition --->
//((rnd(150, 200) / 100) *
left += graphics.getFontMetrics().charWidth(c)+rnd(space, space);
}
// Draw forground lines
if(maxFGLines>0 && maxFGLines>minFGLines) {
int to=rnd(minFGLines,maxFGLines);
for(int i=1;i<=to;i++) {
drawRandomLine(graphics, dimension, getRandomColor(startColor));
}
}
return bufferedImage;
}
/**
* creates a font from given string
* @param font
* @param defaultValue
* @return
*/
public abstract Font getFont(String font, Font defaultValue);
private void drawBackground(Graphics2D graphics, Dimension dimension,int _startColor) {
Color startColor = getRandomColor(_startColor);
Color endColor = getRandomColor(_startColor);
GradientPaint gradientPaint = new GradientPaint(getRandomPointOnBorder(dimension),
startColor,
getRandomPointOnBorder(dimension),
endColor.brighter(),
true);
graphics.setPaint(gradientPaint);
// arguments.graphics.setColor(startColor) />
graphics.fill(new Rectangle(dimension));
}
private Font createFont(List fonts, int fontSize, int shear,int index) {
AffineTransform trans1 = getRandomTransformation(shear, shear);
AffineTransform trans2 = getRandomTransformation(shear, shear);
Font font = (Font) fonts.get(index%fonts.size());
font = font.deriveFont((float)fontSize).deriveFont(trans1).deriveFont(trans2);
return font;
}
private Color getRandomColor(int startColor) {
return new Color(r(startColor),r(startColor),r(startColor));
}
private int r(int startColor) {
return rnd(startColor-100,startColor);
//int r= ((int)(Math.random()*(255-startColor)))+startColor;
//return r;
}
private Point getRandomPointOnBorder(Dimension dimension) {
int height = (int) dimension.getHeight();
int width = (int) dimension.getWidth();
switch(rnd(1, 4)) {
case 1: // left side
return new Point(0, rnd(0, height));
case 2: // right side
return new Point(width, rnd(0, height));
case 3: // top side
return new Point(rnd(0, width), 0);
case 4:
default: // bottom side
return new Point(rnd(0, width), height);
}
}
private AffineTransform getRandomTransformation(int shearXRange, int shearYRange) {
// create a slightly random affine transform
double shearX = rndd(-1 * (shearXRange * (rnd(50, 150) / 100d)), (shearXRange* (rndd(50, 150) / 100d))) / 100d ;
double shearY = rndd(-1 * (shearYRange * (rnd(50, 150) / 100d)), (shearYRange * (rndd(50, 150) / 100d))) / 100d ;
AffineTransform transformation = new AffineTransform();
transformation.shear(shearX, shearY);
return transformation;
}
private BasicStroke getRandomStroke() {
return new BasicStroke(rnd(1, 3));
}
private Point getRandomPoint(Dimension dimension) {
int height = (int) dimension.getHeight();
int width = (int) dimension.getWidth();
return new Point(rnd(0, width), rnd(0, height));
}
protected static int rnd(double min, double max) {
return (int) rndd(min, max);
}
private static double rndd(double min, double max) {
if(min>max) {
double tmp=min;
min=max;
max=tmp;
}
double diff=max-min;
return ((int)(StrictMath.random()*(diff+1)))+min;
}
private void drawRandomLine(Graphics2D graphics, Dimension dimension, Color lineColorType) {
Point point1 = getRandomPointOnBorder(dimension);
Point point2 = getRandomPointOnBorder(dimension);
graphics.setStroke(getRandomStroke());
graphics.setColor(lineColorType);
graphics.drawLine((int)point1.getX(),
(int)point1.getY(),
(int)point2.getX(),
(int)point2.getY());
}
private void drawRandomOval(Graphics2D graphics, Dimension dimension, Color ovalColorType) {
Point point = getRandomPoint(dimension);
double height = dimension.getHeight() ;
//double width = dimension.getWidth() ;
double minOval = height * .10;
double maxOval = height * .75;
graphics.setColor(ovalColorType);
switch(rnd(1, 3)) {
case 1:
graphics.setStroke(getRandomStroke());
graphics.drawOval(
(int)point.getX(),
(int)point.getY(),
rnd(minOval,maxOval),
rnd(minOval,maxOval) );
break;
case 2:
case 3:
graphics.fillOval(
(int)point.getX(),
(int)point.getY(),
rnd(minOval,maxOval),
rnd(minOval,maxOval) );
break;
}
}
}