This is an abstract base class that defines the interface for writing image files of various types. More...

#include "pnmWriter.h"

Inheritance diagram for PNMWriter:

Public Member Functions
void	copy_header_from (const PNMImageHeader &header)
	Initializes all the data in the header (x_size, y_size, num_channels, etc.) to the same values indicated in the given header. More...

PNMFileType *	get_type () const
	Returns a pointer to the PNMFileType object that created this PNMWriter. More...

bool	is_valid () const
	Returns true if the PNMWriter can be used to write data, false if something is wrong. More...

void	set_color_type (ColorType type)

void	set_maxval (xelval maxval)

void	set_num_channels (int num_channels)

void	set_x_size (int x_size)

void	set_y_size (int y_size)

virtual bool	supports_floating_point ()
	Returns true if this PNMFileType can accept a floating-point image type, false if it can only accept a normal, integer type. More...

virtual bool	supports_grayscale () const
	Returns true if this particular PNMWriter understands grayscale images. More...

virtual bool	supports_integer ()
	Returns true if this PNMFileType can accept an integer image type, false if it can only accept a floating-point type. More...

virtual bool	supports_stream_write () const
	Returns true if this particular PNMWriter can write to a general stream (including pipes, etc.), or false if the writer must occasionally fseek() on its output stream, and thus only disk streams are supported. More...

virtual bool	supports_write_row () const
	Returns true if this particular PNMWriter supports a streaming interface to writing the data: that is, it is capable of writing the image one row at a time, via repeated calls to write_row(). More...

virtual int	write_data (xel array, xelval alpha)
	Writes out an entire image all at once, including the header, based on the image data stored in the given _x_size * _y_size array and alpha pointers. More...

virtual bool	write_header ()
	If supports_write_row(), above, returns true, this function may be called to write out the image header in preparation to writing out the image data one row at a time. More...

virtual bool	write_pfm (const PfmFile &pfm)
	Writes floating-point data from the indicated PfmFile. More...

virtual bool	write_row (xel array, xelval alpha)
	If supports_write_row(), above, returns true, this function may be called repeatedly to write the image, one horizontal row at a time, beginning from the top. More...

Public Member Functions inherited from PNMImageHeader
	PNMImageHeader (const PNMImageHeader &copy)

ColorSpace	get_color_space () const

ColorType	get_color_type () const
	Returns the image type of the image, as an enumerated value. More...

std::string	get_comment () const

xelval	get_maxval () const

int	get_num_channels () const

LVecBase2i	get_size () const

PNMFileType *	get_type () const

int	get_x_size () const
	Returns the number of pixels in the X direction. More...

int	get_y_size () const
	Returns the number of pixels in the Y direction. More...

bool	has_alpha () const
	Returns true if the image includes an alpha channel, false otherwise. More...

bool	has_type () const

bool	is_grayscale () const
	Returns false if the image is a full-color image, and has red, green, and blue components; true if it is a grayscale image and has only a gray component. More...

PNMReader *	make_reader (const Filename &filename, PNMFileType *type=nullptr, bool report_unknown_type=true) const
	Returns a newly-allocated PNMReader of the suitable type for reading from the indicated image filename, or NULL if the filename cannot be read for some reason. More...

PNMReader *	make_reader (std::istream file, bool owns_file=true, const Filename &filename=Filename(), std::string magic_number=std::string(), PNMFileType type=nullptr, bool report_unknown_type=true) const
	Returns a newly-allocated PNMReader of the suitable type for reading from the already-opened image file, or NULL if the file cannot be read for some reason. More...

PNMWriter *	make_writer (const Filename &filename, PNMFileType *type=nullptr) const
	Returns a newly-allocated PNMWriter of the suitable type for writing an image to the indicated filename, or NULL if the filename cannot be written for some reason. More...

PNMWriter *	make_writer (std::ostream file, bool owns_file=true, const Filename &filename=Filename(), PNMFileType type=nullptr) const
	Returns a newly-allocated PNMWriter of the suitable type for writing to the already-opened image file, or NULL if the file cannot be written for some reason. More...

void	operator= (const PNMImageHeader &copy)

void	output (std::ostream &out) const

bool	read_header (const Filename &filename, PNMFileType *type=nullptr, bool report_unknown_type=true)
	Opens up the image file and tries to read its header information to determine its size, number of channels, etc. More...

bool	read_header (std::istream &data, const std::string &filename=std::string(), PNMFileType *type=nullptr, bool report_unknown_type=true)
	Reads the image header information only from the indicated stream. More...

void	set_comment (const std::string &comment)

void	set_type (PNMFileType *type)
	Sets the file type of this PNMImage. More...

Additional Inherited Members
Public Types inherited from PNMImageHeader
enum	ColorType { CT_invalid = 0, CT_grayscale = 1, CT_two_channel = 2, CT_color = 3, CT_four_channel = 4 }

typedef pmap< PixelSpec, int >	HistMap

typedef pvector< PixelSpec >	Palette

typedef pvector< PixelSpecCount >	PixelCount

Static Public Member Functions inherited from PNMImageHeader
static bool	has_alpha (ColorType color_type)
	This static variant of has_alpha() returns true if the indicated image type includes an alpha channel, false otherwise. More...

static bool	is_grayscale (ColorType color_type)
	This static variant of is_grayscale() returns true if the indicated image type represents a grayscale image, false otherwise. More...

static bool	read_magic_number (std::istream *file, std::string &magic_number, int num_bytes)
	Ensures that the first n bytes of the file are read into magic_number. More...

Public Attributes inherited from PNMImageHeader
	get_color_space
	Returns the color space that the image is encoded in, or CS_unspecified if unknown. More...

	get_comment
	Gets the user comment from the file. More...

	get_maxval
	Returns the maximum channel value allowable for any pixel in this image; for instance, 255 for a typical 8-bit-per-channel image. More...

	get_num_channels
	Returns the number of channels in the image. More...

	get_size
	Returns the number of pixels in each direction. More...

	get_type
	If the file type is known (e.g. More...

	has_type
	Returns true if the PNMImageHeader knows what type it is, false otherwise. More...

	set_comment
	Writes a user comment string to the image (header). More...

Detailed Description

This is an abstract base class that defines the interface for writing image files of various types.

Any particular image file type that can be written must define a class that inherits from PNMWriter to write it.

Definition at line 27 of file pnmWriter.h.

Member Function Documentation

◆ copy_header_from()

void PNMWriter::copy_header_from ( const PNMImageHeader & header )

inline

Initializes all the data in the header (x_size, y_size, num_channels, etc.) to the same values indicated in the given header.

This should be done before writing anything to the file.

Definition at line 83 of file pnmWriter.I.

Referenced by PfmFile::write(), and PNMImage::write().

◆ get_type()

PNMFileType * PNMWriter::get_type ( ) const

inline

Returns a pointer to the PNMFileType object that created this PNMWriter.

Definition at line 30 of file pnmWriter.I.

◆ is_valid()

bool PNMWriter::is_valid ( ) const

inline

Returns true if the PNMWriter can be used to write data, false if something is wrong.

Definition at line 92 of file pnmWriter.I.

Referenced by PNMImageHeader::make_writer().

◆ supports_floating_point()

bool PNMWriter::supports_floating_point ( )

virtual

Returns true if this PNMFileType can accept a floating-point image type, false if it can only accept a normal, integer type.

If this returns true, write_pfm() is implemented.

Reimplemented in PNMFileTypePfm::Writer.

Definition at line 34 of file pnmWriter.cxx.

Referenced by PfmFile::write().

◆ supports_grayscale()

bool PNMWriter::supports_grayscale ( ) const

virtual

Returns true if this particular PNMWriter understands grayscale images.

If this is false, then the rgb values of the xel array will be pre-filled with the same value across all three channels, to allow the writer to simply write out RGB data for a grayscale image.

Definition at line 112 of file pnmWriter.cxx.

Referenced by PNMImage::write().

◆ supports_integer()

bool PNMWriter::supports_integer ( )

virtual

Returns true if this PNMFileType can accept an integer image type, false if it can only accept a floating-point type.

If this returns true, write_data() or write_row() is implemented.

Reimplemented in PNMFileTypePfm::Writer.

Definition at line 44 of file pnmWriter.cxx.

Referenced by PNMImage::write().

◆ supports_stream_write()

bool PNMWriter::supports_stream_write ( ) const

virtual

Returns true if this particular PNMWriter can write to a general stream (including pipes, etc.), or false if the writer must occasionally fseek() on its output stream, and thus only disk streams are supported.

Definition at line 153 of file pnmWriter.cxx.

◆ supports_write_row()

bool PNMWriter::supports_write_row ( ) const

virtual

Returns true if this particular PNMWriter supports a streaming interface to writing the data: that is, it is capable of writing the image one row at a time, via repeated calls to write_row().

Returns false if the only way to write from this file is all at once, via write_data().

Definition at line 101 of file pnmWriter.cxx.

◆ write_data()

int PNMWriter::write_data	(	xel *	array,
		xelval *	alpha
	)

virtual

Writes out an entire image all at once, including the header, based on the image data stored in the given _x_size * _y_size array and alpha pointers.

(If the image type has no alpha channel, alpha is ignored.) Returns the number of rows correctly written.

It is the user's responsibility to fill in the header data via calls to set_x_size(), set_num_channels(), etc., or copy_header_from(), before calling write_data().

It is important to delete the PNMWriter class after successfully writing the data. Failing to do this may result in some data not getting flushed!

Derived classes need not override this if they instead provide supports_streaming() and write_row(), below.

Definition at line 74 of file pnmWriter.cxx.

References Thread::consider_yield(), write_header(), and write_row().

Referenced by PfmFile::write(), and PNMImage::write().

◆ write_header()

bool PNMWriter::write_header ( )

virtual

If supports_write_row(), above, returns true, this function may be called to write out the image header in preparation to writing out the image data one row at a time.

Returns true if the header is successfully written, false if there is an error.

It is the user's responsibility to fill in the header data via calls to set_x_size(), set_num_channels(), etc., or copy_header_from(), before calling write_header().

Definition at line 127 of file pnmWriter.cxx.

Referenced by write_data().

◆ write_pfm()

bool PNMWriter::write_pfm ( const PfmFile & pfm )

virtual

Writes floating-point data from the indicated PfmFile.

Returns true on success, false on failure.

Reimplemented in PNMFileTypePfm::Writer.

Definition at line 53 of file pnmWriter.cxx.

Referenced by PfmFile::write(), and PNMImage::write().

◆ write_row()

bool PNMWriter::write_row	(	xel *	array,
		xelval *	alpha
	)

virtual

If supports_write_row(), above, returns true, this function may be called repeatedly to write the image, one horizontal row at a time, beginning from the top.

Returns true if the row is successfully written, false if there is an error.

You must first call write_header() before writing the individual rows. It is also important to delete the PNMWriter class after successfully writing the last row. Failing to do this may result in some data not getting flushed!

Definition at line 143 of file pnmWriter.cxx.

Referenced by write_data().

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

panda/src/pnmimage/pnmWriter.h
panda/src/pnmimage/pnmWriter.cxx
panda/src/pnmimage/pnmWriter.I

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ copy_header_from()

◆ get_type()

◆ is_valid()

◆ supports_floating_point()

◆ supports_grayscale()

◆ supports_integer()

◆ supports_stream_write()

◆ supports_write_row()

◆ write_data()

◆ write_header()

◆ write_pfm()

◆ write_row()