changes

PNG开放源接口 The interface has been designed to be as simple and intuitive as possible. It supports plo

########################## PNGwriter #########################################
#
#       Website: Main:             http://pngwriter.sourceforge.net/
#                Sourceforge.net:  http://sourceforge.net/projects/pngwriter/
#                Freshmeat.net:    http://freshmeat.net/projects/pngwriter/
#
#       Author:                    Paul Blackburn
#
#       Email:                     [e-mail]
#
#       Version:                   0.5.3   (24 / I / 2005)
#
#       Description:               Library that allows plotting a 48 bit
#                                  PNG image pixel by pixel, which can
#                                  then be opened with a graphics program.
#
#       License:                   GNU General Public License
#                                  (C) 2002, 2003, 2004, 2005 Paul Blackburn
#
##############################################################################

Changes:

0.5.3
 24 January 2005
 > Added get_text_width() and get_text_width_utf8(). This returns the
   width, in pixels, of the text if it were plotted. This width, used
   with the font size, can help estimate the actual dimensions of the
   plotted text.
 > Added new figures: arrow, cross, maltese cross and diamond.
 > Fixed a small mistake in a plot_text() error message.

0.5.2
 10 January 2005
 > Changed the License. PNGwriter is now released under a plain, standard 
   GNU General Public License, and not a modified one. This is to enable 
   PNGwriter to become a part of the Debian Linux distribution, and also 
   to keep things simple.
 
0.5.1
 3 January 2005
 > Modified the Makefile to make it more suitable for packaging.
 > Modified the PDF manual, to better document the possibility of 
   PNGwriter being installed in a non-default location.
 > Modified the README, to better document the process of installing
   PNGwriter under a non-default directory, using PREFIX.
 > Modified the README, to reflect the actual installed locations of the
   files, as determined by PREFIX at install time. 

0.5.0
 24 October 2004
 > Added the triangle() function for fast plotting of triangles.
 > Fixed a serious bug that affected versions of PNGwriter compiled
   on Windows. Specifically, readfromfile() was opening the file 
   as ASCII ("r") and not binary ("rb"). This would render the PNG
   unreadable to libpng.

0.4.9
 18 October 2004
 > Added the filledtriangle() and filledtriangle_blend() functions for fast
   plotting of filled triangles.
 
0.4.8
 10 October 2004
 > Fixed a few serious bugs introduced in 0.4.7, which was withdrawn a few 
   hours after being released. Since 0.4.7 has not really seen much action, 
   its changes are included in 0.4.8's release notes as well.
 > readfromfile() now correctly determines if the file to be read is a valid
   PNG or not.
 > Yet more improvements in file-related error handling.
 > Fixed a few bugs in the constructors. Though out-of-range background colours
   were checked for, they were not clipped to within the allowed range, despite
   what the error messages said. Also, if a constructor was called with negative
   height or width, nothing was done about it, that too despite what the error 
   messages said. This has now been fixed.
 > 0.4.7's changes are as follows:
 > Fixed a serious bug in readfromfile() which would cause a crash due to
   too many open files if it was called a certain number of times (caused
   by an out-of-place fopen() ).
 > All user supplied text fields (filename and png info) are no longer
   limited to 255 characters.
 > Better handling of file errors: attempting to open a non-existent file
   will no longer cause a crash.
   
0.4.7
 10 October 2004
 > Fixed a serious bug in readfromfile() which would cause a crash due to
   too many open files if it was called a certain number of times (caused
   by an out-of-place fopen() ).
 > All user supplied text fields (filename and png info) are no longer
   limited to 255 characters.
 > Better handling of file errors: attempting to open a non-existent file
   will no longer cause a crash.

0.4.6
 31 August 2004
 > Fixed a bug that did not allow PNGwriter to be compiled with Borland Builder
   or MSVC7 under Windows.
 
0.4.5
 15 August 2004
 > New functions: scale_k(), scale_kxky() and scale_wh(). These allow
   you to scale the image proportionally, non-proportionally, and to a target
   width and height.
 > New functions: Blended Functions. All figures and plotting modes have been
   complemented with blended versions, allowing you to plot any included 
   PNGwriter shape (including text) in blended mode. 
 > New function: laplacian(). Calculates the discrete laplacian of an image.
 > Documentation update: the Quick Reference PDFs have been reformatted
   and reorganized, and the result is easier to use (it looks nicer too!).
   
   
0.4.4
 8 August 2004
 > New functions: Boundary and Flood Fill. For Boundary Fill pixels 
   adjacent to the start pixel will be filled with the fill colour, 
   until the boundary colour is encountered, and for Flood Fill, 
   all pixels adjacent to the start pixel will be filled with the
   fill colour, if they are the same colour as the start pixel.
 > New function: Polygon. This function takes an array of integer 
   values containing the coordinates of the vertexes of a polygon.
 > New functions: Plot and Read CMYK. Plot and read a pixel in the
   Cyan, Magenta, Yellow, Black colourspace.     

0.4.3
 8 July 2004
 > The number of characters rendered with plot_text() is no longer printed
   to stdout. This had been left in by mistake after testing.
   
0.4.2
 5 July 2004
 > New function: plot_text_utf8(). Now you can plot text using characters 
   from any language (accented french and spanish, japanese, korean, etc.).
   Just pass a UTF-8 encoded string to plot_text_utf8() and use a font that 
   supports the characters you will use.
 > New function: resize(). Changes the size of the image. Useful when you create
   an array of PNGwriter instances and you want to change each size after creation.
   Note: this function does not re-scale the image; it resets it to black.

0.4.1
 21 June 2004
 > Updated documentation (some small parts had not been updated since 0.3.7)
 
0.4.0
 20 June 2004
 > PNGwriter has text support!! After many requests, text support
   using the Freetype2 library has been added. The plotted text is 
   antialiased, can be rotated however you want, can use any TrueType 
   font file to plot with, and as if that weren't enough, the text has
   proper kerning.
 > New function: plot_blend(). Similar to plot(), but blends the 
   plotted pixel with the existing pixel, given a number from 0.0
   to 1.0 which regulates the opacity.
 > New function: bilinear_interpolation_read(). The x and y
   coordinates are still in pixel space, but are now of type double. When
   requesting the pixel values in between integer indices, bilinear
   interpolation is used. Smooth image enlargement is now much simpler.
 > New function: invert(). Inverts the image in the RGB colourspace.
 > Faster plot() and read().
 > Faster circle().
 > plot() now checks if the colour coefficients are within range, and 
   clips them if not.
 > read() now checks if the coordinates are in the image space, and if
   not returns 0 (or 0.0 in the case of dread() ).
 > Fixed an unnoticed, unreported long-standing bug in plot().
   Plotting to instances of PNGwriter that have read in an 8-bit
   PNG file now works :-)
 > Updated documentation.
 
0.3.7
 12 October 2003
 > Both branches, English and Spanish, have been merged into one
   bilingual main branch. This is to make the release process easier
   for me. The PNGwriter Quick Reference PDF is now distributed
   only with the main PNGwriter package.
 > PNGwriter is now a library! No more worrying about having
   pngwriter.o and pngwriter.h available.
 > Better error handling. All malloc and new events are now checked
   for failure. readfromfile() now does not crash the program if the file
   cannot be found.
 > New write_png() function. It writes the PNG file to disk. Useful
   for using one PNGwriter instance to make many slightly different
   images in a sequence.
 > pngwriter_rename() has been overloaded to accept an unsigned long
   int. Given 54726 as an argument, for example, it will rename the 
   filename to "000054726.png". In theory one could make up to 999999999
   sequential images before having to change directory and start at
   zero again. This is ideally suited for making movies, using MEncoder,
   for example.
 > The line() function has been completely rewritten. The new
   implementation uses the Bresenham algorithm, which is much faster than
   the old implementation.
 > Assignment operator overloaded, a proper copy constructor, and
   a default constructor.
 > New version() function. It simply returns the PNGwriter version.   
 > Completely rewritten Makefile. It is now much more flexible, better
   written, and clearer than before. Customization for your particular
   system is also much easier.
 > Completely reorganized the PNGwriter package layout. Easier to
   install, and more suited to porting.


0.3.6
 18 September 2003
 > Added the settext() functions to change the PNG header text.

0.3.5
 7 June 2003
 > Added bezier() function for making bezier curves.
 > Fixed a bug in the read() function (line 440 in pngwriter.cc).

0.3.4
 17 January 2003
 > Added setcompressionlevel()
 > Fixed default gamma
 > Improved documentation
 > Added new test program, lyapunov
 > Fixed a bug with the line() function.

0.3.3 
 19 Nov 2002 
  > Where necessary, functions that took "char *" as an argument now accept
 "const char *" as well.
 > Added read(x, y) and dread(x, y) to get the average value of the pixel x, y.
 > Added readHSV(x, y, colour) and dreadHSV(x, y, colour) to get the colour
 of a certain pixel in HSV colourspace.  

0.3.2 
 27 Oct 2002 
 > Added better error reporting.
 > Added plotHSV() to be able to make rainbows.
 > Added double versions of most functions that work in the 0 to 1 range
 instead of 0 to 65535. 
 
0.3.1 
 4 Oct 2002 
 > Implemented support for 16 and 8 bit PNGs for readfromfile(). 

0.3.0
 1 Oct 2002 
 > Added readfromfile(). Now you can open PNGs and play with them with
 pngwriter.

0.2.3
 29 Sep 2002
 > Fixed harmless type mismatch in some functions.
 > Added an explanation to the Makefile, and made it more useful.
  
0.2.2 
 31 Aug 2002 
 > Updated and improved documentation. 
   
0.2.1 
 19 Aug 2002 
 > Fixed the Makefile. 
   
0.2.0 
 18 Aug 2002 
 >Added new functions (line, square, filledsquare, circle, filledcircle).
 >Added PNG info fields. 
   
0.1.0 
 17 Aug 2002 
 >Initial release