ipe::Bitmap Class Reference

#include <ipebitmap.h>

Public Types
enum	Format { None , Png , Jpeg }
enum	Flags {   ERGB = 0x01 , EAlpha = 0x02 , EDCT = 0x04 , EInflate = 0x08 ,   ENative = 0x10 }

Public Member Functions
	Bitmap ()
	Bitmap (int width, int height, uint32_t flags, Buffer data)
	Bitmap (const XmlAttributes &attr, String data)
	Bitmap (const XmlAttributes &attr, Buffer data, Buffer smask)
	Bitmap (const Bitmap &rhs)
	~Bitmap ()
Bitmap &	operator= (const Bitmap &rhs)
void	saveAsXml (Stream &stream, String id, int pdfObjNum=-1) const
bool	isNull () const
bool	equal (Bitmap rhs) const
int	width () const
int	height () const
bool	isJpeg () const
bool	isGray () const
bool	hasAlpha () const
int	colorKey () const
Buffer	pixelData ()
int	objNum () const
void	setObjNum (int objNum) const
String	checksumId (int suffix=0) const
std::pair< Buffer, Buffer >	embed () const
bool	operator== (const Bitmap &rhs) const
bool	operator!= (const Bitmap &rhs) const
bool	operator< (const Bitmap &rhs) const
void	savePixels (const char *fname)
bool	save (const char *fname) const

Static Public Member Functions
static void	saveBitmaps (Stream &stream, std::vector< Bitmap > &bitmaps)
static const char *	readJpegInfo (FILE *file, int &width, int &height, Vector &dotsPerInch, uint32_t &flags)
static Bitmap	readJpeg (const char *fname, Vector &dotsPerInch, const char *&errmsg)
static Bitmap	readPNG (const char *fname, Vector &dotsPerInch, const char *&errmsg)
static Bitmap	read (const char *fname, Vector &dotsPerInch, const char *&errmsg)
static Format	formatFromFile (const char *fname)

Detailed Description

A bitmap.

Bitmaps are explicitely shared using reference-counting. Copying is cheap, so Bitmap objects are meant to be passed by value.

The bitmap provides a slot for short-term storage of an "object number". The PDF embedder, for instance, sets it to the PDF object number when embedding the bitmap, and can reuse it when "drawing" the bitmap.

Member Enumeration Documentation

Format

enum ipe::Bitmap::Format

Enumerator
None
Png
Jpeg

Flags

enum ipe::Bitmap::Flags

Enumerator
ERGB
EAlpha
EDCT
EInflate
ENative

Constructor & Destructor Documentation

Bitmap() [1/5]

Bitmap::Bitmap

(

)

Default constructor constructs null bitmap.

Referenced by read(), readJpeg(), and readPNG().

Bitmap() [2/5]

Bitmap::Bitmap	(	int	width,
		int	height,
		uint32_t	flags,
		Buffer	data
	)

Create a new image from given image data.

If you already have data in native-endian ARGB32 without premultiplication, pass it with flag ENative. Otherwise pass a byte stream and set ERGB and EAlpha correctly: EAlpha: each pixel starts with one byte of alpha channel, ERGB: each pixel has three bytes of R, G, B, in this order, otherwise each pixel has one byte of gray value.

References height(), and width().

Bitmap() [3/5]

Bitmap::Bitmap	(	const XmlAttributes &	attr,
		String	data
	)

Create from XML stream.

References ipe::String::data(), ipe::Buffer::data(), ipe::Base64Source::getChar(), ipe::Lex::getHexByte(), height(), isGray(), ipe::String::size(), and width().

Bitmap() [4/5]

Bitmap::Bitmap	(	const XmlAttributes &	attr,
		Buffer	data,
		Buffer	smask
	)

Create from XML using external raw data.

Bitmap() [5/5]

Bitmap::Bitmap

(

const Bitmap &

rhs

)

Copy constructor.

Since Bitmaps are reference counted, this is very fast.

~Bitmap()

Bitmap::~Bitmap

(

)

Destructor.

Member Function Documentation

operator=()

Bitmap & Bitmap::operator=

(

const Bitmap &

rhs

)

Assignment operator (takes care of reference counting).

Very fast.

saveAsXml()

void Bitmap::saveAsXml	(	Stream &	stream,
		String	id,
		int	pdfObjNum = -1
	)		const

Save bitmap in XML stream.

References ipe::Base64Stream::close(), colorKey(), embed(), hasAlpha(), height(), isGray(), isJpeg(), ipe::Base64Stream::putChar(), ipe::Stream::putXmlString(), and width().

Referenced by ipe::Document::saveAsXml().

isNull()

bool ipe::Bitmap::isNull ( ) const

inline

Is this a null bitmap?

Referenced by ipe::Painter::drawExternalBitmap(), ipe::Image::Image(), save(), ipe::Document::saveAsXml(), saveBitmaps(), and ipe::Image::setBitmap().

equal()

bool Bitmap::equal

(

Bitmap

rhs

)

const

width()

int ipe::Bitmap::width ( ) const

inline

Return width of pixel array.

Referenced by Bitmap(), Bitmap(), ipe::CairoPainter::doDrawBitmap(), embed(), pixelData(), readJpeg(), readJpegInfo(), readPNG(), save(), saveAsXml(), and savePixels().

height()

int ipe::Bitmap::height ( ) const

inline

Return height of pixel array.

Referenced by Bitmap(), Bitmap(), ipe::CairoPainter::doDrawBitmap(), embed(), pixelData(), readJpeg(), readJpegInfo(), readPNG(), save(), saveAsXml(), and savePixels().

isJpeg()

bool ipe::Bitmap::isJpeg ( ) const

inline

Is this bitmap a JPEG photo?

References EDCT.

Referenced by embed(), pixelData(), save(), saveAsXml(), and savePixels().

isGray()

bool ipe::Bitmap::isGray ( ) const

inline

Is the bitmap grayscale?

References ERGB.

Referenced by Bitmap(), embed(), and saveAsXml().

hasAlpha()

bool ipe::Bitmap::hasAlpha ( ) const

inline

Does the bitmap have transparency?

Bitmaps with color key will return false here.

References EAlpha.

Referenced by embed(), pixelData(), and saveAsXml().

colorKey()

int ipe::Bitmap::colorKey ( ) const

inline

Return the color key or -1 if none.

Referenced by pixelData(), and saveAsXml().

pixelData()

Buffer Bitmap::pixelData

(

)

Return pixels for rendering.

Returns empty buffer if it cannot decode the bitmap information. Otherwise, returns a buffer of size width() * height() uint32_t's. The data is in cairo ARGB32 format, that is native-endian uint32_t's with premultiplied alpha.

References colorKey(), hasAlpha(), height(), isJpeg(), and width().

Referenced by ipe::CairoPainter::doDrawBitmap().

objNum()

int ipe::Bitmap::objNum ( ) const

inline

Return object number of the bitmap.

Referenced by ipe::PdfPainter::doDrawBitmap(), ipe::Document::saveAsXml(), ipe::Image::saveAsXml(), saveBitmaps(), and setObjNum().

setObjNum()

void ipe::Bitmap::setObjNum ( int  objNum ) const

inline

Set object number of the bitmap.

References objNum().

Referenced by saveBitmaps().

checksumId()

String Bitmap::checksumId

(

int

suffix = 0

)

const

Return checksum as a hexadecimal string, possibly augmented by suffix.

References ipe::Stream::putHexByte().

Referenced by ipe::Image::saveAsXml(), and saveBitmaps().

saveBitmaps()

void Bitmap::saveBitmaps ( Stream &  stream, std::vector< Bitmap > &  bitmaps  )

static

Save all the bitmaps, assigning objNum to distinguish equal checksums.

References checksumId(), isNull(), objNum(), and setObjNum().

Referenced by ipe::Page::saveAsIpePage(), ipe::StyleSheet::saveAsXml(), ipe::Document::saveAsXml(), and ipe::Page::saveSelection().

embed()

std::pair< Buffer, Buffer > Bitmap::embed

(

)

const

Create the data to be embedded in an XML or PDF file.

For Jpeg images, this is simply the bitmap data. For other images, rgb/grayscale data and alpha channel are split and deflated separately.

References ipe::Buffer::data(), ipe::DeflateStream::deflate(), hasAlpha(), height(), isGray(), isJpeg(), ipe::Buffer::size(), and width().

Referenced by saveAsXml().

operator==()

bool ipe::Bitmap::operator== ( const Bitmap &  rhs ) const

inline

Two bitmaps are equal if they share the same data.

operator!=()

bool ipe::Bitmap::operator!= ( const Bitmap &  rhs ) const

inline

Two bitmaps are equal if they share the same data.

operator<()

bool Bitmap::operator<

(

const Bitmap &

rhs

)

const

Less operator, to be able to sort bitmaps.

The checksum is used. When checksums are equal, compares the actual contents. After sorting, bitmaps with equal checksum form contiguous blocks. Identical bitmaps form smaller blocks within those blocks, and bitmaps with shared implementation form even smaller blocks within those.

readJpegInfo()

const char * Bitmap::readJpegInfo ( FILE *  file, int &  width, int &  height, Vector &  dotsPerInch, uint32_t &  flags  )

static

Read information about JPEG image from file.

Returns NULL on success, an error message otherwise. Sets flags to EDCT and possibly ERGB.

References EDCT, ERGB, height(), and width().

Referenced by readJpeg().

readJpeg()

Bitmap Bitmap::readJpeg ( const char *  fname, Vector &  dotsPerInch, const char *&  errmsg  )

static

Read JPEG image from file.

Returns the image as a DCT-encoded Bitmap. Sets dotsPerInch if the image file contains a resolution, otherwise sets it to (0,0). If reading the file fails, returns a null Bitmap, and sets the error message errmsg.

References Bitmap(), ipe::String::data(), ipe::Platform::fopen(), height(), ipe::Platform::readFile(), readJpegInfo(), ipe::String::size(), and width().

Referenced by ipe::BitmapCache::load(), and read().

readPNG()

Bitmap Bitmap::readPNG ( const char *  fname, Vector &  dotsPerInch, const char *&  errmsg  )

static

Read PNG image from file.

Returns the image as a Bitmap. It will be compressed if deflate is set. Sets dotsPerInch if the image file contains a resolution, otherwise sets it to (0,0). If reading the file fails, returns a null Bitmap, and sets the error message errmsg.

References Bitmap(), ipe::Buffer::data(), EAlpha, ERGB, ipe::Platform::fopen(), height(), and width().

Referenced by ipe::BitmapCache::load(), and read().

read()

Bitmap Bitmap::read ( const char *  fname, Vector &  dotsPerInch, const char *&  errmsg  )

static

References Bitmap(), formatFromFile(), Jpeg, Png, readJpeg(), and readPNG().

formatFromFile()

Bitmap::Format Bitmap::formatFromFile ( const char *  fname )

static

References ipe::Platform::fopen(), Jpeg, None, and Png.

Referenced by read().

savePixels()

void Bitmap::savePixels

(

const char *

fname

)

References ipe::Buffer::data(), ipe::Platform::fopen(), height(), isJpeg(), and width().

save()

bool Bitmap::save

(

const char *

fname

)

const

Save as JPEG (without re-encoding) or PNG, preserving straight-alpha pixels.

Returns false if the bitmap is null, encoding fails, or writing fails.

References ipe::Platform::fopen(), height(), isJpeg(), isNull(), ipe::size(), and width().

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The documentation for this class was generated from the following files:

• ipebitmap.h
• ipebitmap.cpp
• ipebitmap_unix.cpp
• ipebitmap_win.cpp