org.daisy.dotify.api.graphics

Class BrailleGraphics

java.lang.Object

org.daisy.dotify.api.graphics.BrailleGraphics

public class BrailleGraphics
extends Object

Provides basic braille graphics support using standard braille patterns.

Constructor Summary

Constructors

Constructor and Description
BrailleGraphics(boolean eightDot) Creates a new instance of braille graphics, with either full 8-dot or 6-dot patterns.

Method Summary

Modifier and Type	Method and Description
static List<String>	combine(List<String> background, List<String> overlay, int x, int y) Combines two braille images by combining characters from the two input images.
List<String>	renderGraphics(Raster r) Renders the raster using braille characters.
static List<String>	sixDotFilter(List<String> input) Filters the input braille image by discarding dots 7 and 8.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BrailleGraphics

public BrailleGraphics(boolean eightDot)

Creates a new instance of braille graphics, with either full 8-dot or 6-dot patterns.

Parameters:

eightDot - true if full 8-dot patterns should be used, false otherwise.

Method Detail

renderGraphics

public List<String> renderGraphics(Raster r)

Renders the raster using braille characters. It is assumed, in both 6-dot and 8-dot mode, that the next line follows directly after the previous line ends. In other words, no pixels are skipped in either mode. To get a better diagonal representation in 6-dot mode, render in 8-dot mode and filter the result using sixDotFilter.

Parameters:

r - the raster to render

Returns:

a braille image using characters in the range 0x2800-0x28FF or 0x2800-0x283F

sixDotFilter

public static List<String> sixDotFilter(List<String> input)

Filters the input braille image by discarding dots 7 and 8.

Parameters:

input - the braille input, characters in the range 0x2800-0x28FF

Returns:

the filtered braille image, characters in the range 0x2800-0x283F

combine

public static List<String> combine(List<String> background,
                                   List<String> overlay,
                                   int x,
                                   int y)

Combines two braille images by combining characters from the two input images. The overlay image overwrites a portion of the background image where it is placed. Bounds checking is performed to ensure that the overlay image is placed completely within the size of the background data.

Parameters:

background - the image onto which data is to be placed

overlay - the image to place onto the background

x - the overlay offset in characters

y - the overlay offset in rows

Returns:

returns the combined image

Throws:

IllegalArgumentException - if x or y is negative, or if the overlay are out of bounds of the background image.