Package de.uniks.networkparser.bytes.qr

Class BitMatrix

java.lang.Object

de.uniks.networkparser.bytes.qr.BitMatrix

All Implemented Interfaces:

java.lang.Cloneable

public final class BitMatrix
extends java.lang.Object
implements java.lang.Cloneable

Represents a 2D matrix of bits. In function arguments below, and throughout the common module, x is the column position, and y is the row position. The ordering is always x, y. The origin is at the top-left.

Internally the bits are represented in a 1-D array of 32-bit ints. However, each row begins with a new int. This is done intentionally so that we can copy out a row into a BitArray very efficiently.

The ordering of bits is row-major. Within each int, the least significant bits are used first, meaning they represent lower x values. This is compatible with BitArray's implementation.

Constructor Summary

Constructors

Constructor	Description
BitMatrix(int dimension)
BitMatrix(int width, int height)

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears all bits (sets to false).
BitMatrix	clone()
boolean	equals(java.lang.Object o)
void	flip(int x, int y)	Flips the given bit.
boolean	get(int x, int y)	Gets the requested bit, where true means black.
int[]	getBottomRightOnBit()
int[]	getEnclosingRectangle()	This is useful in detecting the enclosing rectangle of a 'pure' barcode.
int	getHeight()
de.uniks.networkparser.bytes.qr.BitArray	getRow(int y, de.uniks.networkparser.bytes.qr.BitArray row)	A fast method to retrieve one row of data from the matrix as a BitArray.
int	getRowSize()
int[]	getTopLeftOnBit()	This is useful in detecting a corner of a 'pure' barcode.
int	getWidth()
int	hashCode()
static BitMatrix	parse(java.lang.String stringRepresentation, java.lang.String setString, java.lang.String unsetString)
void	rotate180()	Modifies this BitMatrix to represent the same but rotated 180 degrees
void	set(int x, int y)	Sets the given bit to true.
void	setRegion(int left, int top, int width, int height)	Sets a square region of the bit matrix to true.
void	setRow(int y, de.uniks.networkparser.bytes.qr.BitArray row)
java.lang.String	toString()
java.lang.String	toString(java.lang.String setString, java.lang.String unsetString)
void	unset(int x, int y)

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BitMatrix

public BitMatrix(int dimension)

BitMatrix

public BitMatrix(int width,
                 int height)

Method Detail

parse

public static BitMatrix parse(java.lang.String stringRepresentation,
                              java.lang.String setString,
                              java.lang.String unsetString)

get

public boolean get(int x,
                   int y)

Gets the requested bit, where true means black.

Parameters:

x - The horizontal component (i.e. which column)

y - The vertical component (i.e. which row)

Returns:

value of given bit in matrix

set

public void set(int x,
                int y)

Sets the given bit to true.

Parameters:

x - The horizontal component (i.e. which column)

y - The vertical component (i.e. which row)

unset

public void unset(int x,
                  int y)

flip

public void flip(int x,
                 int y)

Flips the given bit.

Parameters:

x - The horizontal component (i.e. which column)

y - The vertical component (i.e. which row)

clear

public void clear()

Clears all bits (sets to false).

setRegion

public void setRegion(int left,
                      int top,
                      int width,
                      int height)

Sets a square region of the bit matrix to true.

Parameters:

left - The horizontal position to begin at (inclusive)

top - The vertical position to begin at (inclusive)

width - The width of the region

height - The height of the region

getRow

public de.uniks.networkparser.bytes.qr.BitArray getRow(int y,
                                                       de.uniks.networkparser.bytes.qr.BitArray row)

A fast method to retrieve one row of data from the matrix as a BitArray.

Parameters:

y - The row to retrieve

row - An optional caller-allocated BitArray, will be allocated if null or too small

Returns:

The resulting BitArray - this reference should always be used even when passing your own row

setRow

public void setRow(int y,
                   de.uniks.networkparser.bytes.qr.BitArray row)

Parameters:

y - row to set

row - BitArray to copy from

rotate180

public void rotate180()

Modifies this BitMatrix to represent the same but rotated 180 degrees

getEnclosingRectangle

public int[] getEnclosingRectangle()

This is useful in detecting the enclosing rectangle of a 'pure' barcode.

Returns:

enclosing rectangle of all 1 bits, or null if it is all white left,top,width,height

getTopLeftOnBit

public int[] getTopLeftOnBit()

This is useful in detecting a corner of a 'pure' barcode.

Returns:

coordinate of top-left-most 1 bit, or null if it is all white x,y

getBottomRightOnBit

public int[] getBottomRightOnBit()

getWidth

public int getWidth()

Returns:

The width of the matrix

getHeight

public int getHeight()

Returns:

The height of the matrix

getRowSize

public int getRowSize()

Returns:

The row size of the matrix

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

string representation using "X" for set and " " for unset bits

toString

public java.lang.String toString(java.lang.String setString,
                                 java.lang.String unsetString)

Parameters:

setString - representation of a set bit

unsetString - representation of an unset bit

Returns:

string representation of entire matrix utilizing given strings

clone

public BitMatrix clone()

Overrides:

clone in class java.lang.Object