Revision history for Graphics-Framebuffer

1.00    2004

        First version, released privately only, as part of a Perl
		media player project called "SuperSparky".

4.02    Dec 29, 2013

        Public CPAN release.  This is considerably more advanced
		than the one distributed as part of the media player.

4.03    March 20, 2014

        Minor changes to the CPAN package

4.05    April 14, 2014

        Documentation updates.  POD section revamped.

4.06    July 19, 2014

        Added better testing

        Added framebuffer emulation mode for test running on systems
        without a hardware framebuffer.  It draws to a 640x480x32
        virtual screen in memory.  You can dump this screen to a file.
        
4.07    July 23, 2014

        Fixed calculation error in string size allocation for emulation
        mode.

        Fixed fill 'flood' typo.

        Fixed pixel class documentation.  It was incorrect.

        Added more tests for most used methods.

4.08    July 25, 2014

        Added additional information to the documentation for the new
        emulation mode.  No actual code changes made.

4.09    November 26, 2014

        Added more FBIOCTL flags to make ready for future hardware
        accellerated updates.  No promises here, but heck, this
        entire module was an exercise in "can it be done in Perl?"
        
        Also fixed a code comment that was mislabeled.

4.10    May 10, 2015

        Added the ability to customize the framebuffer file path.
        Thanks Markus Maier.
        
        Added aliases to "set_mode"

        Some minor documentation fixes.

4.11    July 03, 2015

        Numerous changes.

        Changed ttf_print box_mode to return everything needed to call itself
        again.

        Added a 'COLOR_ORDER' setting to the "new" parameters.  1=RGB and 0=BGR.
        The default is BGR.

        Added more comments to the code

        Added 'reset' as an alias to 'attributes_reset'.  Just for people with
        different tastes.

        Hardened the code further against undefined values.

        Added more documentation

        Tested on Raspberry PI2, and works great!  Odroid XU3, not so much...

        Circle/ellipse clipping weirdness remains.  I should have that addressed
        in the next release.

4.12    July 05, 2015

        Minor POD fix

        There was a POD error that caused it to fail testing, although it would
        have worked fine if installed.

        No new functionality in this release, just that one issue fixed.

4.13    July 06, 2015

        Changed the tests to only test against a memory buffer.

        The tests get screwed up by the Test::Harness' output (which can't be
        squelched apparently).  So instead of testing on the real framebuffer,
        I force the tests on a pseudo memory buffer.

        I believe I have fixed the clipping issues, especially the ones with
        filled ellipses and circles.  It was related to blit_write.

        There are some minor optimizations, although likely not obvious.

4.14    July 07, 2015

        Fixed borked plot test.  Functionality of the module is fine.  The test
        was broken.

4.15    July 07, 2015

        Optimizations!

        I have optimized the draw_arc routine, and in the process made it
        properly work with XOR mode as well.  It only draws what it hasn't
        drawn before.  Which makes it quite faster (although still not a speed
        demon).

4.16    July 14, 2015

        Bug fixes

        Fill is now fixed.  This sucker still uses stack memory like it's going
        out of style.  You have been warned.

        Filled polygons now, as long as they aren't overly complicated, and the
        borders do not cross.  It uses a history buffer when drawing and then
        uses it to draw a series of horizontal lines to "fill" the polygon. This
        fill is very fast as a result.

        'line' added for an alternate way of drawing a line.  It's essentially
        a combination of plot > drawto under the hood.

        Warnings have been completely turned off.  We don't want warnings to
        mess up your pretty graphics.  Crashable code is in an eval, so who
        cares?  Generally warnings begin happening when Perl has done a
        variable garbage collection, and the memory mapping to the framebuffer
        is borked.  Fortunately, the module now recovers from this and remaps
        it.

        Clipping is quicker and more robust.

        Documentation has been updated / fixed where appropriate.

4.17    July 14, 2015

        Fixed bugs as a result of some typos.  Sorry about that.
        This affected the draw_arc and ellipse routines.
        
        Made poly arcs draw with lines instead of single pixels.  That fills in
        the errors left by high granularity.
        
        Added the constants 'ARC', 'PIE', and 'POLY_ARC' to make drawing arcs
        easier to code.

4.18    July 14, 2015

        Added new arc drawing methods.  See the POD docs (man) for details.

4.19    July 16, 2015

        Fixed the POD errors on test.  I could swear I tested that.  Oh well.

4.20    July 16, 2015

        Removed the harmless leftover SCREEN2 code.  Since that variable no
        longer existed, the code skips by it.

4.21    July 16, 2015

        Ugh, I left "Data::Dumper::Simple" in the previous version.  Build
        was borking on machines without it.  Sorry folks.

        I try to leave out all debugging code to keep the module as fast as
        possible, but I missed this one.

4.22    July 21, 2015

        I added a new mode to the framebuffer engine.  Typically the module
        uses a memory mapped method to draw to the framebuffer.  It's fast,
        but on some systems, this may be unstable.  In such cases, you have
        the option of telling the drawing engine to use a file handle mode
        instead.  File handle mode is a little slower, so use this mode
        only if necessary.  See the manual for specifics.

4.23    July 21, 2015

        Modified the testing to stop failing too easy.  It's really not
        catestrophic if a test fails.  Testing kind of interferes with
        the output anyway.

        Consolided the tests into one single "primitives" test.

        ARM Mali GPUs now work.  I found the problem was the framebuffer
        driver was returning some bogus data, and was throwing off the
        calculations for drawing.  Which caused crazy numbers to be
        sent to the mmap call, and thus fail.  Now an override can be
        sent when initializing the module to fix this.  Yes, this means
        that this module now works on the Odroid XU3!

        The scripts in the "examples" directory can be put into MALI mode
        by simply passing "mali" on the command line.

        I added a boxfill for hardware accelerated cards.  It's automatic
        when called by box/rbox in the API.  It only works with filled
        boxes in normal and XOR mode.

        If hardware accelerated filled boxes aren't working, then you
        can disable them by setting (assume $fb is your object variable)
        $fb->{'accel_flags'} = 0

        Oh, and blitcopy is hardware accelerated in normal mode only as
        well, if your video card supports it.

4.24    July 23, 2015

        Vertical Gradents for boxes, ellipses, circles, and polygons
        added.  See the documentation for details.  See the "examples"
        directory for... well... examples.
        
        Polygon fills fixed.  No more gaps.  Go easy on the complex
        filled polygons though.  Sometimes you get better results by
        making a complex filled polygon out of smaller simple ones.

        Updated the examples with up-to-date tests.

        Added "UNMASK_MODE" to the documentation.  Sorry about not having it
        in there in the first place.  I also added the shortcut method
        "unmask_mode".

        Added "angle_line" method for drawing lines at specific angles.

5.00    July 31, 2015

        Major version update.

        So many things have been added and optimized, that it warrants a full
        version number upgrade.

        'replace_color' is VERY fast if clipping is reset (off)

        'pie_arc' has been changed.  It uses the same fill routine that the
        polygon fill uses.  Thus it draws a lot faster with no more gaps.
        Granularity is not as important.  The value of 0.01 for granularity
        should work for most uses (unless you have a 4K screen).

        'fill' Is a lot faster, and uses considerably less memory now.  I
        knew I'd get it down.

        New 'monochrome' method that takes any image data and makes it
        greyscale.  Using it with the blit methods should be handy.

        TrueType font rendering is improved.  It has a default font setting,
        which you can change when you instantiate the framebuffer.  It also
        takes a new parameter 'wscale' to scale the width of the text.  It
        takes decimal values between 1 (inclusive) to 0 (exclusive).  1
        is normal, and smaller values squeeze the text.

        Color conversions are a bit better for 16 bit framebuffers.

        Added 'cubic_bezier' curves!  Yes, you can be a spline master now.

        More friendlier named methods that are aliases to others.

        Due to the extra features, two more prerequisite modules are
        required.
        
        On that note, I removed the need for Switch.pm. It turns out it's
        flakey and starts to give bizarre errors, not to mention I realized
        it has a performance penalty. So yes, this module is a little bit
        faster now as a result.

        Boxes can have rounded corners in frame, filled, and gradient
        filled modes, if you desire.  Just add the parameter 'radius'
        to the method call.

        Polygons with rounded corners are not ready.  I am still having
        trouble with them, but they will be added eventually.

        This new version comes with a splash screen, which can be turned off.

        The scripts in the 'examples' directory have been updated to reflect
        the new additions.  They should be very helpful in getting you
        started.

        Please read the manual for info on the new additions.

5.01    August 03, 2015

        Fixed colorspace handling.  Whether your video card is RGB or BGR (or
        anything else), the module handles it fine.  Also, 32, 24, and 16 bit
        color modes are fully supported now.  Note, 16 bit is a bit slower due
        to the need for bit shifting.  So I recommend 32 bit.

        Color replace (replace_color) is now fixed, and quite a bit faster.
        Super-fast if you do it without clipping (clip_reset).

        More code optimizations have been added for speed.

        cls/screen_clear have been changed a bit to be more effective when
        clipping is off.  You can also enable/disable the console cursor if
        you pass 'ON' or 'OFF' to them.

        Splash screen contains info on the video card, and if hardware
        acceleration is used.  It also indicates which color order RGB are
        (look at the 'GFB' in the upper left circle, they are colored
        according your video card's order).

5.02    August 03, 2015

        Discontinued "cubic_bezier' and replaced it with 'bezier'.  It was so
        young, but this needed to be done.  It will still work, but I don't
        suggest continuing to use it.  It's now just an alias to 'bezier'.

        New 'bezier' method can create complex multi-point curves and shapes.
        If a closed shape, it can be filled too.

        Module prerequisites changed.

        Optimized rounded corner box drawing.

5.03    August 05, 2015

        Improved the IOCTL handling.  A lot of work there.  Still can't figure
        out why Mali and Nouveau are not giving the needed information to
        properly draw.  The size of the framebuffer is improperly reported by
        the Mali driver, and the size of a line is improperly reported by the
        Nouveau driver.  It seems Nouveau requires an additional 192 bytes per
        line.,, weird.

        So, to compensate for weirdness, I added another option to the 'new'
        method, LINE_PADDING.  With this one and MALI, I hope I have the quirks
        covered.

        Optimized the rounded box algorithm for solid fills a bit more.

        Changed the splash screen a bit.

        Changed the examoples scripts to fall in line with the changes.

5.04    August 06, 2015

        Optimized circles and boxes with rounded corners... by a lot.

5.05    August 08, 2015

        Fixed load_image, and added color remapping as well.

5.06    August 08, 2015

        Documentation for 'load_image' was incorrect.  'load_image' returns
        a structure containing the image for display with 'blit_write'.

5.07    August 08, 2015

        Fixed the 32/24/16 bit conversions for image loading.

5.08    August 08, 2015

        Ugh, I left some debug code in one of the examples scripts.

5.09    August 09, 2015

        Updated the documentation.

        Updates to set_color and related methods
        
5.10    August 09, 2015

        Fixed a bug in xoffset calculations.

5.11    August 10, 2015

        Fixed a POD error

5.12    August 11, 2015

        Improved color replace.  It's a lot faster for clipped mode.

        Modified the test scripts to dynamically adjust to the resolution of
        the device.  This way the tests look fine on all devices, even tiny
        96x64 OLED devices.

        I was handling hardware acceleration incorrectly, which is why it
        didn't work (duh).  Right now it's just turned off.  It requires
        Inline C code, and I am not prepared for that yet.

5.13    August 11, 2015

        More fixes to line drawing and blitting routines.

        Made test scripts completely resolution independent.  They should
        display sane graphics for even the smallest displays.

5.14    August 12, 2015

        Hardened memory mapping.

        If mmap fails more than twice, it now just switches to file handle mode.
        Apparently when mmap fails, in some environments, the file handle
        disappears as well.  Attempts are also made to recover the file handle
        too.

        Tests now check to see if run in X-Windows.  Naughty naughty those of
        you not reading the instructions!  I don't like receiving CPAN reporter
        errors when the error is not reading the instructions (wink wink).

5.15    August 12, 2015

        Added a real test pattern to image tests

5.16    August 13, 2015

        Fixed color mapping for ttf_print

5.17    August 13, 2015

        Removed MALI and LINE_PADDING parameters.
        
        Byte aligning helped figure out the driver paramenter structures.

5.18    August 13, 2015

        Moved the images into their own directory

        Modified the scripts to work with the images.

5.19    August 13, 2015

        Replaced some for[each] loops with map for just that slight boost
        of speed.  Every optimization helps.

5.20    August 14, 2015

        Fixed the color mapping for the TrueType font rendering.  This was
        most obvious in 16 bit modes.  However, because of the complexities
        in this process, text rendering for 16 bit modes is slower, as it
        has to convert the 24 bit output of Imager into a 16 bit image to
        then blit to the screen.  I will see if there are optimizations I can
        do for this in the future.  Meanwhile it works.

        Rounded box rendering has been fixed.  It was showing an error in the
        right side of the boxes mostly.  This is no longer an issue.

        Fixed the splash screen to show something coherrant on very low
        resolution displays, like adafruit displays for example (96x64x16).

        I have also forced buffer flushes on the screen filehandle.  It was
        buffering the drawing, which was leaving artifacts and driving me
        crazy.  Fortunately, this doesn't affect speed, as I don't tell it to
        flush the buffer until after the entire primitive is drawn.

5.21    August 14, 2015

        Modified clear_screen a bit.

        Made changes to the test and examples scripts.

5.22    August 14, 2015

        I somehow reintroduced some clipping errors I had previously fixed.
        Well, those are fixed once again.

5.23    August 16, 2015

        I fixed one last clipping bug in horizontal line drawing and the top
        of the screen.

5.24    August 17, 2015

        Mostly documentation updates.

        'threadtest.pl' was no longer showing what each thread was doing.  It
        must have been related to the buffering fixes for the graphics.  Doing
        a flush on STDOUT seems to have fixed it.

5.25    August 18, 2015

        Added assign colorspace ability to emulation mode.  No longer is it
        just RGB.  You can define it yourself.

5.26    August 19, 2015

        Fixed image load routine.

5.27    August 19, 2015

        Fixed POD errors

5.28    August 20, 2015

        The polygon fill has been completely rewritten.  It has one minor
        requirement though, that all polygons need to be drawn with their
        points in a clockwise direction.  Keep that in mind and filled
        polygons will look great.

5.29    August 20, 2015

        Documentation changes

        Improved a couple of the example scripts

5.30    August 21, 2015

        'image_load' now allows you to define the type of scaling to use, if
        the image is to be scaled.

        A few minor changes to the example scripts.

5.31    August 25, 2015

        Re-wrote the algorithm that retrieves the framebuffer ioctl structures
        Different CPU types really throw this off, and attempting to use c2ph
        shows that c2ph is broken.  Hopefully this algorithm works.

        Included further install documentation, as it seems installing Imager
        from CPAN can result in a useless Imager if the necessary libraries aren't
        present ahead of time.

5.32    August 25, 2015

        Fixed some typos

5.33    August 26, 2015

        Improved the IOCTL detection code further.  It just goes to fbset if it
        gets confused.  (#@$%@# C structures)

        Added further documentation on installation and troubleshooting.

        Added a disagnostics script call "dump.pl" in the "examples" directory.
        I may ask you to send me the output of this, if you contact me for help.

5.34    August 26, 2015

        Horizontal gradients are now allowed (in addition to the vertical).  See
        the documentation for details.  Surprisingly, this draws faster on some
        primitives.  It's not perfect yet though.  Polygon fills seem to have
        some issues.

5.35    August 28, 2015

        Improved cursor show/hide in clear_screen/cls.

        Added more tests to primitives.pl.  Made slideshow.pl show on all
        framebuffer devices on the system automatically.

5.36    August 29, 2015

        Changed the Build.PL and Makefile.PL scripts to be more informative
        and check for 'fbset' as well.

        Removed the test 01-environment.t script.  It was causing far too much
        trouble with automated CPAN tester bots (I hate getting CPAN Tester
        failure emails).

        The example script "mmapvsfile.pl" now actually makes a recommendation
        on which mode to use for your framebuffer device, as some SPI
        connected TFT devices actually work much faster in file handle mode
        instead of memory mapped mode (go figure).

5.37    August 31, 2015

        Fixed the 'angle_line' bug.  It just plain wasn't working right.  Now
        it is.

        Added the 'last_plot' method to return the current X,Y cursor position.

        Added an 'angle_line' call to the "primitives.pl" script.

5.38    September 03, 2015

        Fixed load_image to actually work with center parameter.

        load_image now loads images with multiple frames (animated gifs).

        Added new method "blit_transform", which rotates, scales, flips, and
        merges blit images.

        Update the "examples" scripts to show off new methods.

5.39    September 03, 2015

        Fixed a time bug on primitives.pl that showed up on slow machines.

5.40    September 03, 2015

        Fixed the Perl 5.22+ hard error in load_image while checking for
        Imager based errors.  Instead of "defined(@Img)" I changed it to
        "defined($Img[0])".  Which is functionally equivalent to what I
        need to check, as the first element needs to be defined anyway.
        This should make new Perls happy.

5.41    September 05, 2015

        Fixed the animated GIF rendering issue with transparency.  No more
        ugly black splotches.

        Changed example scripts. Added more images with different
        characteristics.

5.42    September 14, 2015

        Fixed incorrect color mapping for horizontal gradient fills in 16 bit
        mode.

        Added a color mapping test for "primitives.pl".

        Changed how images are loaded for very low resolution screens in
        "primitives.pl".

5.43    September 16, 2015

        Fixed circle bug with XOR draswing mode.

        Fixed MASK and UNMASK drawing modes.  They previously didn't even work.

        Removed some old legacy unused code.

        Overhauled the examples scripts, especially "primitives.pl".

        Gutted the old testing scripts.  They were just for show, and never
        really were testing anything.  Due to Perl's taint mode, which test
        uses, it was more trouble than it was worth.  Now, if you see the
        splash screen, it works and is properly tested, sufficiently for
        installing.

5.44    September 18, 2015

        Fixed a majorly annoying and long-term clipping bug with blit_write.
        This was causing corruption and over drawing for horizontal gradients.

5.45    September 18, 2015

        Added "convertalpha" parameter to "load_image".  This finds all
        occurances of the background color and gives it the alpha value in the
        global background that is set.  This makes for overlaying via
        "blit_transform" in "merge" mode much easier, and pretty much replaces
        MASK and UNMASK mode for blitting (they will stay for compatibility).
        Note, alpha only works for 32 bit mode.  This parameter does nothing
        in 24 and 16 bit screen modes.

5.46    September 19. 2015

        I left "use threads" in when it was no longer needed.  I had been
        experimenting with using threads internally, but neglected to remove
        those lines when I trashed the idea.

        Also "use Config" was removed as well.  It was used previously in "new"

5.47    September 19, 2015

        Added system variable $obj->{'FONTS'}, which contains all of the fonts
        found in the system.  It is a hash in the format:

             'facename' => {
                 'path' => 'path to font',
                 'font' => 'file name of font'
             }

        The module now assigns the default font from a list of possible fonts
        that should be installed, instead of just "FreeSans".  This should
        alieviate the fonts issue when testing.

        The method "get_font_face" has been fixed, as it wasn't working as
        documented.

5.48    September 21, 2015

        Fixed rotate to work properly for 16 bit mode.  Imager doesn't do 16
        bit RGB565, so this rotate has to be coded in Perl for 16 bit mode
        instead.
        
        Added the transform "monochrome" to "blit_transform".  It does the
        same as the "monochrome" method.  It was placed in "blit_transform"
        for consistency.

        The example script "primitives.pl" has been better coded to know
        if it's in 16 mode and leave out tests that don't work in that mode.
        I have also shrunk down the "MASK" and "UNMASK" graphics sizes to
        save some time in their rendered output, as they can be SLOOOW,
        especially on a Raspberry PI.

5.49    September 23, 2015

        Some code optimization and documentation improvements

        Added a new "get_fonts_list" method.  It returns a hash of all of
        the system fonts.

        Build.PL was broken.  I'm surprised nobody notified me of this.  It
        is fixed now.

5.50    September 25, 2015

        Added PODs to all examples scripts, and cleaned up excisting POD in
        the module itself.  TODO has been cnverted to a POD file.

        Redesigned "primitives.pl", but gives the same output.

        Added "blit_transform" -> "merge" examples as alternatives to
        "MASK" and "UNMASK" drawing modes in "primitives.pl".

        Some speed optimizations were made to the module.  Nothing dramatic,
        but a help, nevertheless.

        Minor changes to the splash screen.

5.51    September 25, 2015

        Fixed manifying POD weirdness for TODO

5.52    September 27, 2015

        Fixed RGB_to_16 routine.  It was affecting truetype rendering in
        16 bit mode, mapping the wrong colors.

        Improved the splash screen.  It adjusts to each resolution better.

        Added the YouTube channel to the README and POD manual.

5.53    September 30, 2015

        Made 16 bit monochrome work a bit better.  It's not perfect and
        yields a violet hue, but it's not as ugly as before.

        "primitives.pl" in the "examples" directory adapts for Raspberry PIs
        to prevent tests that take too long.

5.54    October 02, 2015

        Added the ability to merge a smaller graphic on top of a larger one
        in "blit_transform" -> "merge".  It now takes into consideration the
        X and Y values for the top graphic.

        "examples/primitives.pl" has been updated to better demonstrate
        MASK, UNMASK modes and the faster alternative "blit_transform" with
        "merge".

5.55    October 03, 2015

        Renamed a few color conversion methods.  Anything mentioning "RGB",
        "RGBA", or "16" are now "RGB888", "RGBA8888", and "RGB565"
        respectively.

        Improved 16 bit conversions.  Monochrome should be fixed for 16 bit
        now.  I still emphasize that you avoid 16 bit if possible.

        Some documentation additions.  System variables are listed.

5.56    October 05, 2015

        Added antialiased line drawing.  'drawto', 'line', 'angle_line' and
        'polygon' is affected.  Antialiased drawing is slower, so it is an
        extra parameter to turn it on or off.
        
        Updated 'examples/primitives.pl' to demonstrate antialiased lines.

        Fixed a bug in 'blit_transform' for 'monochrome'.  It just wasn't
        working, although the method 'monochrome' was.

        Revamped the documentation.  Hopefully I got all the formatting
        errors and outdated parameters on some methods.

        The method 'ttf_print' now has a 'wscale' parameter for scaling the
        width of the text.

5.57    January 28, 2016

        The method "screen_dimensions" was incorrectly returning the virtual
        resolution instead of the actual.

5.58    March 18, 2016

        Added method "which_console".  This method returns the current active
        console and the console when started.

5.59    March 18, 2016

        Forgot to document the updates

5.60    March 20, 2016

        Added "sys/ioctl.ph" require.  Changed "screen_dump" to allow for JPEG
        etc.

5.61    March 31, 2016

        Split splash code off to "Graphics::Framebuffer::Splash"

5.62    April 02, 2016

        Fixed the perl rotation code for 16 bit, but also added a switch to use
        it in other color depths via "perl_only".

5.63    April 11, 2016

        Some speed optimizations.  Nothing major.

        Removed the "sys/ioctl.ph" require.  It just was too flakey.

5.70    April 15, 2016

        Significant upgrade!  Texture fills and hatch fills have been added.

        Documentation updated to reflect the new features.

        Fills for primitives has been optimized further.  It's a bit faster.
        This has the side effect of also decreasing the TrueType rendering
        time.

        Polygon fills are fixed, and so are the filled pies.

        "replace_color" has been significantly optimized.  It's faster in
        memory mapped mode and file handle mode.

        TrueType Font rendering now has the ability to rotate the text on
        an arbitray angle.  Box calculation isn't perfect.  Trying padding
        with spaces, should you have issues.

        Example scripts changed to demonstrate new features.

        Imager is preloaded "Imager->preload" for more thread friendly use.
        It didn't have issues before, but this is safer, and according to
        its documentation, it should be done.

5.71    April 15, 2016

        Oops, accidentally left a "use Carp" in there.  It's gone now.

5.72    April 15, 2006

        New method "acceleration" added to toggle Imager assistance and get
        its status.  The unused method "acceleration_disable" has been
        removed.

        The method "screen_dimensions" now returns more information if called
        in a scalar context.

        The method "get_font_list" now returns an array reference of hashes
        matching the face name, if more than one match for the name is found.

        The "blit_transform" method now allows for 16 bit use, but it WILL
        BE SLOWER.  Why?  GFB has to convert your 16 bit bitmap data into
        24 bit before it can get Imager to work with it.  It then has to
        convert it back into 16 bit when Imager is done.  This is not a
        Road Runner friendly operation, especially with a slow CPU.  Rotate
        and flip use their own Perl native algorithms.  So they will be
        speedier for 16 bit (relatively speaking).  If you have the ability,
        use 32 bit color mode.  Things are so much faster.

        "flood_fill" acceleration x,y clipping offset fixed.  Although there
        seems to be another issue with this.  You may have to turn off
        acceleration for this method for the time being, if your system
        renders it funny.

        Demo image files in the "examples/images" directory optimized for
        space, so the tarball is smaller.  Also two images missing from
        the manifest added.

        More speed optimizations.  It seems "foreach my $var (0 .. 100)" is
        considerably faster than "for (my $var;$var <= 100;$var++)".  Where
        possible, this change was made, and a noticeable change it was.

5.73    April 24, 2016

        The Perl 'rotate' algorithm in the method 'blit_transform' has been
        corrected, optimized, and now no longer clips the output.  Rotations
        that are a multiple of 90 degrees use an optimized routine instead of
        the standard rotation algorithm.  Note, this routine only is used
        in 16 bit mode or when 'acceleration(0)' has been set.

        Image loading has been modified to automatically scale images larger
        than the output device (without clipping set).  This overrides any
        scaling values larger than the screen resolution.

        Most of the blitting issues with textures fixed.  Especially the
        mirroring issue with ellipses.

        Drawing mode "alpha" now works properly.

        'center' added to the method 'blit_transform' for easy centering of
        images.

        Greatly modified and improved the scripts in the 'examples' directory.
        In 'primitives.pl', most of the images are preloaded into memory.
        This reduces or eliminates waiting between stages.  Images used for
        textures, etc. are randomly chosen for most examples.

        New method "play_animation" plays animated GIFs loaded via the
        'load_image' method.