Fonts
#####

Bitmap Fonts
============

The Micropython firmware image provided includes 12 bitmap fonts converted from
pc bios text mode fonts for use with the tftui module. The fonts are encoded as
frozen byte code and can be imported and used directly from flash to conserve
RAM.

|

Font file format
----------------

.. literalinclude:: fontformat.py
   :linenos:
   :language: python
   :caption: Example python font file.

|

Bitmap Font Tables
------------------

|

vga1_8x8
^^^^^^^^

.. image:: images/vga1_8x8.jpg

|

vga2_8x8
^^^^^^^^
.. image:: images/vga2_8x8.jpg


|

vga1_8x16
^^^^^^^^^
.. image:: images/vga1_8x16.jpg


|

vga2_8x16
^^^^^^^^^

.. image:: images/vga2_8x16.jpg


|

vga1_16x16
^^^^^^^^^^

.. image:: images/vga1_16x16.jpg


|

vga2_16x16
^^^^^^^^^^

.. image:: images/vga2_16x16.jpg


|

vga1_bold_16x16
^^^^^^^^^^^^^^^

.. image:: images/vga1_bold_16x16.jpg


|

vga2_bold_16x16
^^^^^^^^^^^^^^^

.. image:: images/vga2_bold_16x16.jpg


|

vga1_16x32
^^^^^^^^^^

.. image:: images/vga1_16x32.jpg


|

vga2_16x32
^^^^^^^^^^

.. image:: images/vga2_16x32.jpg


|

vga1_bold_16x32
^^^^^^^^^^^^^^^

.. image:: images/vga1_bold_16x32.jpg


|

vga2_bold_16x32
^^^^^^^^^^^^^^^
.. image:: images/vga2_bold_16x32.jpg


|

Vector Fonts
============

Introduction
------------

The TurtlePlotBot uses the public domain |hershey| fonts distributed on the
USENET network. The Hershey Fonts were originally created by Dr. A. V. Hershey
while working at the U. S. National Bureau of Standards.

.. note::

    The format of the Font data in this distribution was originally
    created by:

   ::

        James Hurt
        Cognition, Inc.
        900 Technology Park Drive
        Billerica, MA 01821
        (mit-eddie!ci-dandelion!hurt)

The fonts range from simple to complex and include many symbols. The standard
TurtlePlotBot does not have the movement accuracy to make all of the fonts
practical. The more complex the font or the longer the message the more the
movement errors will distort the text drawn.

Font file format
----------------

You do not have to understand the font file format in order to use the fonts in
TurtlePlotBot programs the library takes care of the details with the `write`
function.

The font files begin with a 8 bit byte containing the number of characters in
the front followed by a sequence of (little endian) 16 bit unsigned integers
containing the file offset to the coordinate data for each of the characters in
the font file. Fonts with 96 characters are in ASCII order for characters 0x20
though 0x7f. Other fonts have characters starting at 0x00.

The first byte of the coordinate data contains the number of x,y coordinates
for the glyph. The second and third byte contain the coordinates for the left
and right limits of the glyph. The following pairs of bytes are the x and y
coordinates that make glyph. Like the original Hershey data each byte is offset
by 0x52 (ascii 'R'). A value of -50 for the x coordinate is used to indicate
the pen should be raised for the next move.

LCD Font Demo
-------------

.. literalinclude:: ../../programs/show_fonts.py
   :linenos:
   :language: python


Vector Font Tables
------------------

astrol.fnt
^^^^^^^^^^
.. image:: images/astrol.svg
   :align: center


cyrilc.fnt
^^^^^^^^^^
.. image:: images/cyrilc.svg
   :align: center


gotheng.fnt
^^^^^^^^^^^
.. image:: images/gotheng.svg
   :align: center


gothger.fnt
^^^^^^^^^^^
.. image:: images/gothger.svg
   :align: center


gothita.fnt
^^^^^^^^^^^
.. image:: images/gothita.svg
   :align: center


greekc.fnt
^^^^^^^^^^
.. image:: images/greekc.svg
   :align: center


greekcs.fnt
^^^^^^^^^^^
.. image:: images/greekcs.svg
   :align: center


greekp.fnt
^^^^^^^^^^
.. image:: images/greekp.svg
   :align: center


greeks.fnt
^^^^^^^^^^
.. image:: images/greeks.svg
   :align: center


italicc.fnt
^^^^^^^^^^^
.. image:: images/italicc.svg
   :align: center


italiccs.fnt
^^^^^^^^^^^^
.. image:: images/italiccs.svg
   :align: center


italict.fnt
^^^^^^^^^^^
.. image:: images/italict.svg
   :align: center


japan.fnt
^^^^^^^^^
.. image:: images/japan.svg
   :align: center


lowmat.fnt
^^^^^^^^^^
.. image:: images/lowmat.svg
   :align: center


marker.fnt
^^^^^^^^^^
.. image:: images/marker.svg
   :align: center


meteo.fnt
^^^^^^^^^
.. image:: images/meteo.svg
   :align: center


misc.fnt
^^^^^^^^
.. image:: images/misc.svg
   :align: center


music.fnt
^^^^^^^^^
.. image:: images/music.svg
   :align: center


romanc.fnt
^^^^^^^^^^
.. image:: images/romanc.svg
   :align: center


romancs.fnt
^^^^^^^^^^^
.. image:: images/romancs.svg
   :align: center


romand.fnt
^^^^^^^^^^
.. image:: images/romand.svg
   :align: center


romanp.fnt
^^^^^^^^^^
.. image:: images/romanp.svg
   :align: center


romans.fnt
^^^^^^^^^^
.. image:: images/romans.svg
   :align: center


romant.fnt
^^^^^^^^^^
.. image:: images/romant.svg
   :align: center


scriptc.fnt
^^^^^^^^^^^
.. image:: images/scriptc.svg
   :align: center


scripts.fnt
^^^^^^^^^^^
.. image:: images/scripts.svg
   :align: center


symbol.fnt
^^^^^^^^^^
.. image:: images/symbol.svg
   :align: center


uppmat.fnt
^^^^^^^^^^
.. image:: images/uppmat.svg
   :align: center