com.github.cage.image
Class Painter

java.lang.Object
  com.github.cage.image.Painter

public class Painter
extends Object

This class does most of the captcha drawing. This class is thread safe.

Author:

akiraly

DEFAULT_WIDTH

public static final int DEFAULT_WIDTH

Default image width.

See Also:

Constant Field Values

DEFAULT_HEIGHT

public static final int DEFAULT_HEIGHT

Default image height.

See Also:

Constant Field Values

Painter

public Painter()

Constructor.

Painter

public Painter(Random rnd)

Constructor.

Parameters:

rnd - random generator to be used, can be null

Painter

public Painter(int width,
               int height,
               Color bGround,
               Painter.Quality quality,
               EffectConfig effectConfig,
               Random rnd)

Constructor.

Parameters:

width - captcha image width, default DEFAULT_WIDTH

height - captcha image height, default DEFAULT_HEIGHT

bGround - background color of captcha image, default white, can be null

quality - captcha image quality, default Painter.Quality.MAX, should use max it does not have measurable speed penalty on modern jvm-s (1.6u23), can be null

effectConfig - used to define what effects should be used, can be null

rnd - random generator to be used, can be null

draw

public BufferedImage draw(Font font,
                          Color fGround,
                          String text)

Generates a new captcha image.

Parameters:

font - will be used for text, not null

fGround - will be used for text, not null

text - this will be rendered on the image, not null, not 0 length

Returns:

the generated image

createImage

protected BufferedImage createImage()

Creates a new image to draw upon.

Returns:

new image, not null

configureGraphics

protected Graphics2D configureGraphics(Graphics g,
                                       Font font,
                                       Color fGround)

Configures graphics object before drawing text on it.

Parameters:

g - to be configured must be an instance of Graphics2D, not null

font - to be used for the text, not null

fGround - to be used for the text, not null

Returns:

g casted to Graphics2D or throws exception if g is not instance of Graphics2D.

configureGraphicsQuality

protected void configureGraphicsQuality(Graphics2D g2)

Sets quality related hints based on the quality field of this object.

Parameters:

g2 - to be configured, not null

draw

protected void draw(Graphics2D g,
                    String text)

Does some of the text transformation (calls transform(Graphics2D, String, GlyphVector)), scales, transforms and draws the result (also the outline if needed).

Parameters:

g - to be drawn upon

text - to be drawn

transform

protected void transform(Graphics2D g,
                         String text,
                         GlyphVector v)

Does some of the text transformation (like rotation and symbol crowding).

Parameters:

g - to be drawn upon

text - to be drawn

v - graphical representation of text, to be transformed

postProcess

protected BufferedImage postProcess(BufferedImage img)

Does some post processing on the generated image if needed. Like rippling (waving) and blurring.

Parameters:

img - to be post prosessed.

Returns:

the finished image, maybe the same as the input

fillBlurArray

protected void fillBlurArray(float[] array)

Generates a random probability distribution. Used by blurring.

Parameters:

array - filled with random values. The values in array sum up to 1.

getWidth

public int getWidth()

Returns:

width of the image

getHeight

public int getHeight()

Returns:

height of the image

getBackground

public Color getBackground()

Returns:

background color of the image, not null

getQuality

public Painter.Quality getQuality()

Returns:

quality level of the image, not null

getEffectConfig

public EffectConfig getEffectConfig()

Returns:

configuration for effects, not null