GRAPHICS-FRAMEBUFFER

Note, this module does NOT work (natively) in Microsoft Windows

PREREQUISITES

This module REQUIRES access to the video framebuffer, usually
"/dev/fb0". You must be using a video device and driver that exposes
this device to software. Video cards with their proprietary drivers are
not likely to work. However, most open-sourced drivers, seem to work
fine. VirtualBox drivers work too. You must also have the appropriate
permissions to write to this device (usually membership with group
"video").

Sometimes you can force a VESA framebuffer console driver to be loaded
by adding a video mode to the grub command line. You can do this with
some proprietary video drivers that don't have their own framebuffer
drivers.

ATTENTION CPAN TESTERS! Please make sure the above is noted before testing (and marking a fail)

I highly recommend you install the system (or package) version of the
"Imager" library, as it is already pre-compiled with all the needed C
libraries for it to work with this module. In Yum (RedHat) and Aptitude
(Debian/Ubuntu) this module is called "libimager-perl" (or
"perl-libImager"). However, if you desire to install it yourself, please
do it manually, and not via CPAN. When you do it manually, you can see
the missing C libraries it is looking for in the "Makefile.PL" process
and stop it there. You can then install these libraries until it no
longer says something is missing. You see, it just turns off
functionality if it can't find a library (when installing from CPAN),
instead of stopping. Libraries usually missing are those for GIF, JPEG,
PNG, TrueType and FreeType fonts. These are necessary not optional, if
you wish to be able to work with fonts and images.

The "build-essential" tools need to be installed. This is generally a C
compiler, linker, and standard C libraries (usually gcc variety). The
module "Inline::C", which this module uses, requires it. Also, the
package "kernel-headers".

You should also install typical TTF fonts as well. I suggest the Windows
fonts (fonts-wine), Ubuntu fonts (fonts-ubuntu) and anything else you
wish to use.

INSTALLATION

You SHOULD install this module from the console, not X-Windows.

To make your system ready for this module, then please install the
following:

DEBIAN BASED SYSTEMS (Ubuntu, Mint, Raspian, etc):

sudo apt update`
sudo apt install build-essential libimager-perl libinline-c-perl libmath-gradient-perl libmath-bezier-perl libfile-map-perl libtest-most-perl libsys-cpu-perl fonts-wine

REDHAT BASED SYSTEMS (Fedora, CentOS, etc):

sudo yum update
sudo yum upgrade kernel-headers build-essential perl-math-gradient perl-math-bezier perl-file-map perl-imager perl-inline-c perl-sys-cpu perl-test-most

Continuing...

With that out of the way, you can now install this module.

To install this module, run the following commands:

perl Makefile.PL
make
make test
make install

NOTE: _The install step may require sudo (root access)._

_Build.PL is not supported by Inline::C, and thus not by this module as
well._

FURTHER TEST SCRIPTS

To test the installation properly. Log into the text console (not X). Go
to the 'examples' directory and run 'primitives.pl'. It basically calls
most of the features of the module.

The scripts beginning with 'thread' requires 'Sys::CPU'. It is not
listed as a prerequisite for this module (as it isn't), but if you want
to run the threaded scripts, then this is a required module. It
demonstrates how to use this module in a threaded environment.

Mario Roy's MCE test scripts have been added (well, a script to go get
them) to demonstrate alternate multiprocessing methods of using
Graphics::Framebuffer, even with Perls built without threads support.

GETTING STARTED

There is a script template in the 'examples' directory in this package.
You can use it as a starting point for your script. It is conveniently
called 'template.pl' or "threaded_template.pl". I recommend copying it,
renaming it, and leaving the original template intact for use on another
project.

COMPATIBILITY vs. SPEED

This module, suprisingly, runs on a variety of hardware with accessible
framebuffer devices. The only limitation is CPU power. Why CPU power?
The module uses the CPU for its graphics calculations and drawing, not
the GPU. There are very little framebuffer drivers that use the GPU for
anything, and thus no reliable libraries for calling the GPU at the
framebuffer level.

Some lower clocked ARM devices may be too slow for practical use of all
of the methods in this module, but the best way to find out is to run
'examples/primitives.pl' to see which are fast enough to use.

Here's what I have tested this module on (all 1920x1080x32):

- RASPBERRY PI2/3 - Tollerable, I did 16 bit mode testing and coding
on this machine. Using a Perlbrew custom compiled Perl helps a bit.
The Raspberry PI are configured, by default, to be in 16 bit
graphics mode. This is not the best mode if you are going to be
loading images or rendering TrueType text, as color space
conversions can take a long time (with acceleration off). Overall,
32 bit mode works best on this machine, especially for image loading
and text rendering. This performance limitation can, however, be
minimized using the C acceleration features, if you still wish to
use the 16 bit display mode.

- ODROID XU3/XU4 - Surprisingly fast. All methods plenty fast enough
for heavy use. Works great with threads too, 8 of them (when done
properly). Most coding for this module is done on this machine at
1920x1080x32. This is fast enough for full screen (1920 x 1080 or
less) animations at 30 fps. If your resolution is lower, then your
FPS rating will be higher.

- ATOM 1.60 GHZ WITH NVIDIA NOUVEAU DRIVER - Decent, not nearly as
fast as the Odroid XU3/4. Works good with threads too (when done
properly). Great for normal graphical apps and static displayed
output. Recent versions of the Nouveau framebuffer driver have
become noticably slower now days though.

- 2.6 GHZ MACBOOK WITH VIRTUALBOX - Blazingly fast. Most primitives
draw nearly instantly.

- WINDOWS 10 PC WITH VIRTUALBOX, 4 GHZ 6 CORE I7 CPU AND 2 NVIDIA 970
TI'S - Holy cow! No, seriously, this sucker is fast! I wonder how
much faster if it were running Linux natively? In addition,
3840x2160x32 (4K) is surprisingly fast. Who'd have thought? Full
screen animations were choppy, but everything else was plenty fast
enough.

- NATIVE LINUX MINT WITH 4.2 GHZ 6 CORE I7 CPU AND 2 NVIDIA 1080
TI'S - This is how I found out that the Nouveau driver is very poor
when handling a framebuffer. It's actually disgraceful at how bad
and how slow it really is. It doesn't appear to be using any DMA for
the memory copy of the framebuffer, but CPU itself for transfers.
Running Virtual Box on Windows is much faster than running Linux
natively with the Nouveau framebuffer drivers. Sad, really sad.

- NVIDIA JETSON NANO WITH 4GB OF RAM - Plenty zippy. I am quite
pleased with this offering by NVidia.

SUPPORT AND DOCUMENTATION

After installing, you can find documentation for this module with the
'perldoc' command.

perldoc Graphics::Framebuffer _(You may have to install 'perldoc', but
this usually works.)_

man Graphics::Framebuffer _(Installing 'perldoc' usually enables Perl
module man pages)_

You can also look for information at:

- RT - CPAN's request tracker (report bugs here) -
http://rt.cpan.org/NoAuth/Bugs.html?Dist=Graphics-Framebuffer

- ANNOCPAN - Annotated CPAN documentation -
http://annocpan.org/dist/Graphics-Framebuffer

- CPAN RATINGS - http://cpanratings.perl.org/d/Graphics-Framebuffer

- SEARCH CPAN - http://search.cpan.org/dist/Graphics-Framebuffer/

- YOUTUBE - https://youtu.be/4Yzs55Wpr7E

LICENSE AND COPYRIGHT

This program is free software; you can redistribute it and/or modify it
under the terms of either: the GNU General Public License as published
by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.