The class 'bmpfile' is an elementary interface that can be used to read or create and write images in the uncompressed Windows BMP format. More...

#include <bitmaps.h>

Public Member Functions
	bmpfile (int _rows=20)
	The only allowed constructor.
	~bmpfile ()
	The destructor.
int	open (const char *filename, int mode=0, int quiet=0)
	Opens a bmp file for reading (mode = ReadOnly) or editing (mode = ReadWrite).
int	create (const char filename, int _width, int _height, int _bitsperpixel=24, int _pallength=0, int32 _pallette=NULL, int quiet=0)
	Create a bmp file (only 1- and 24-bit supported - sorry!).
void	invertedpicture (int _inverted=1)
	Sets processing of the invertec picture, as stored in the file.
int	writeheader (void)
	Writes the header to the file.
int32	getpixel (int x, int y, bool index=false)
	Reads the true color of a pixel or its index if 'index = true'.
int32	putpixel (int x, int y, long color=0, bool index=false)
	Writes a pixel and returns its true color.
void	drawpixel (int x, int y, int thickness=1, long color=0, bool index=false)
	Writes a thick pixel and returns its true color.
void	drawsegment (int x1, int y1, int x2, int y2, int thickness=1, long color=0, bool index=false)
	Draws a segment built of pixels, with the desired thickness.
int	picture_width (void)
	Returns the width of the picture.
int	picture_height (void)
	Returns the height of the picture.
void	flush (void)
	Flushes the buffers to update the contents BMP file.
int	getbitsperpixel (void)
	Returns the current number of bits per pixel in the picture.
unsigned char *	getrow (int row)
	Returns the pointer to the given row stored in the memory.
unsigned	getrowlength () const
	Returns the length of a row stored in the memory.
int32 *	getpalette (void)
	Returns a pointer to the current color palette (if any).
int	getpallength (void)
	Returns the length of the current color palette (if any).
Public Attributes
int32	x_resolution
	The X resolution of the picture (in dpi).
int32	y_resolution
	The Y resolution of the picture (in dpi).
long	rows_read
	The counter of rows read from a BMP file.
long	rows_written
	The counter of rows written to a BMP file.
Private Member Functions
int	readrow (int row)
	Reads the current row from the file to the memory.
int	writerow (int row)
	Writes the current row from the memory to the file.
Private Attributes
char *	header
	The header of the bitmap file.
int	pallength
	Palette length (in 32-bit words).
int32 *	palette
	The palette buffer.
bool	palette_allocated
	Has the palette memory been allocated?
int *	rownumber
	The numbers of rows stored in the memory.
unsigned char **	rowbuf
	The rows of the picture stored in the memory.
char *	changed
	Flags that indicate which rows have been changed.
unsigned char *	defined
	Flags that indicate which rows have been defined.
int	current
	The current row.
int	bmpstart
	The offset of the bitmap beginning in the file.
unsigned	rowlength
	The length of a row in the bitmap (in bytes).
int	bitsperpixel
	The number of bits per pixel in the bitmap file.
int	width
	The actual width of the picture stored in the file.
int	height
	The actual height of the picture stored in the file.
FILE *	fbmp
	The binary stream containing the picture file.
int	fileinuse
	The type of the bitmap file: 0 = none, 1 = read, 2 = write, 3 = r/w.
int	firstundefinedrow
	The number of the first row undefined in the picture.
int	firstundefinedbyte
	The number of the first undefined byte in the BMP file that has not yet been written after creating the file.
int	rows
	The number of rows allocated in the memory.
unsigned char	fillbyte
	The value of the byte to fill empty lines (background).
int	inverted
	A flag that remembers whether the inverted picture should be processed.

Detailed Description

The class 'bmpfile' is an elementary interface that can be used to read or create and write images in the uncompressed Windows BMP format.

It supports black-and-white as well as color bitmap images.

Definition at line 67 of file bitmaps.h.

Constructor & Destructor Documentation

chomp::homology::bmpfile::bmpfile ( int _rows = 20 )

The only allowed constructor.

Defines the number of rows that are stored in the memory. For optimal performance, this should be set to the height of the picture (if known).

chomp::homology::bmpfile::~bmpfile ( )

The destructor.

Member Function Documentation

int chomp::homology::bmpfile::create	(	const char *	filename,
		int	_width,
		int	_height,
		int	_bitsperpixel = `24`,
		int	_pallength = `0`,
		int32 *	_pallette = `NULL`,
		int	quiet = `0`
	)

Create a bmp file (only 1- and 24-bit supported - sorry!).

Set "x_resolution" and "y_resolution" before or 0 will be assumed. If you change these parameters later, you must rewrite the header;. Returns: 0 = Ok, -1 = Can't create, -2 = Can't write header, -3 = Can't write palette, -4 = Bad params, -5 = Not supported, -6 = Memory allocation error occurred. Displays a message in case of error.

void chomp::homology::bmpfile::drawpixel	(	int	x,
		int	y,
		int	thickness = `1`,
		long	color = `0`,
		bool	index = `false`
	)

Writes a thick pixel and returns its true color.

void chomp::homology::bmpfile::drawsegment	(	int	x1,
		int	y1,
		int	x2,
		int	y2,
		int	thickness = `1`,
		long	color = `0`,
		bool	index = `false`
	)

Draws a segment built of pixels, with the desired thickness.

void chomp::homology::bmpfile::flush ( void )

Flushes the buffers to update the contents BMP file.

int chomp::homology::bmpfile::getbitsperpixel ( void )

Returns the current number of bits per pixel in the picture.

int32* chomp::homology::bmpfile::getpalette ( void ) [inline]

Returns a pointer to the current color palette (if any).

Definition at line 166 of file bitmaps.h.

References palette.

{ return palette; };

int chomp::homology::bmpfile::getpallength ( void ) [inline]

Returns the length of the current color palette (if any).

Definition at line 169 of file bitmaps.h.

{ return pallength; };

int32 chomp::homology::bmpfile::getpixel	(	int	x,
		int	y,
		bool	index = `false`
	)

Reads the true color of a pixel or its index if 'index = true'.

Note: The coordinates start with (0,0).

unsigned char* chomp::homology::bmpfile::getrow ( int row )

Returns the pointer to the given row stored in the memory.

Please, use this function with caution!

unsigned chomp::homology::bmpfile::getrowlength ( ) const

Returns the length of a row stored in the memory.

void chomp::homology::bmpfile::invertedpicture ( int _inverted = 1 ) [inline]

Sets processing of the invertec picture, as stored in the file.

This results in the Y axis running from bottom to top, like in mathematics, unlike in computers.

Definition at line 110 of file bitmaps.h.

References inverted.

                {inverted = _inverted;};

int chomp::homology::bmpfile::open	(	const char *	filename,
		int	mode = `0`,
		int	quiet = `0`
	)

Opens a bmp file for reading (mode = ReadOnly) or editing (mode = ReadWrite).

Returns: 0 = Ok, -1 = Not found, -2 = Can't read header, -3 = Can't read palette, -4 = Not BMP, -5 = Not supported, -6 = Memory allocation error occurred. Displays a message in case of error.

int chomp::homology::bmpfile::picture_height ( void ) [inline]

Returns the height of the picture.

Definition at line 138 of file bitmaps.h.

{ return height; };

int chomp::homology::bmpfile::picture_width ( void ) [inline]

Returns the width of the picture.

Definition at line 135 of file bitmaps.h.

References width.

{ return width; };

int32 chomp::homology::bmpfile::putpixel	(	int	x,
		int	y,
		long	color = `0`,
		bool	index = `false`
	)

Writes a pixel and returns its true color.

int chomp::homology::bmpfile::readrow ( int row ) [private]

Reads the current row from the file to the memory.

int chomp::homology::bmpfile::writeheader ( void )

Writes the header to the file.

Returns: 0 = Ok, -1 = Error (no messages displayed).

int chomp::homology::bmpfile::writerow ( int row ) [private]

Writes the current row from the memory to the file.

Member Data Documentation

int chomp::homology::bmpfile::bitsperpixel [private]

The number of bits per pixel in the bitmap file.

Definition at line 212 of file bitmaps.h.

int chomp::homology::bmpfile::bmpstart [private]

The offset of the bitmap beginning in the file.

Definition at line 206 of file bitmaps.h.

char* chomp::homology::bmpfile::changed [private]

Flags that indicate which rows have been changed.

Definition at line 191 of file bitmaps.h.

int chomp::homology::bmpfile::current [private]

The current row.

Definition at line 197 of file bitmaps.h.

unsigned char* chomp::homology::bmpfile::defined [private]

Flags that indicate which rows have been defined.

Definition at line 194 of file bitmaps.h.

FILE* chomp::homology::bmpfile::fbmp [private]

The binary stream containing the picture file.

Definition at line 221 of file bitmaps.h.

int chomp::homology::bmpfile::fileinuse [private]

The type of the bitmap file: 0 = none, 1 = read, 2 = write, 3 = r/w.

Definition at line 225 of file bitmaps.h.

unsigned char chomp::homology::bmpfile::fillbyte [private]

The value of the byte to fill empty lines (background).

Definition at line 242 of file bitmaps.h.

int chomp::homology::bmpfile::firstundefinedbyte [private]

The number of the first undefined byte in the BMP file that has not yet been written after creating the file.

Definition at line 236 of file bitmaps.h.

int chomp::homology::bmpfile::firstundefinedrow [private]

The number of the first row undefined in the picture.

Normally it will be the height of the picture, since rows are numbered starting with 0. It is important while creating a BMP picture so that the program knows where to begin writing the empty rows if any.

Definition at line 232 of file bitmaps.h.

char* chomp::homology::bmpfile::header [private]

The header of the bitmap file.

Definition at line 169 of file bitmaps.h.

int chomp::homology::bmpfile::height [private]

The actual height of the picture stored in the file.

Definition at line 218 of file bitmaps.h.

int chomp::homology::bmpfile::inverted [private]

A flag that remembers whether the inverted picture should be processed.

This is the order of rows as stored in the file, with the vertical axis Y running from the bottom to the top of the screen.

Definition at line 248 of file bitmaps.h.

Referenced by invertedpicture().