Font service
~~~~~~~~~~~~

Circle provides a simple display font service, which allows to convert ISO-8859-1 (Latin1) character codes into pixel information for displaying characters on dot-matrix displays.

System fonts
^^^^^^^^^^^^

.. code-block:: cpp

	#include <circle/font.h>

.. cpp:struct:: TFont

	This structure is the basic descriptor for a defined system font. The following fonts are available:

	===============	=======	=======	===============	============ ==========
	Font		Width	Height	Extra height	Total height Remarks
	===============	=======	=======	===============	============ ==========
	Font6x7		6	7	1		8
	Font8x8		8	8	2		10
	Font8x10	8	10	2		12
	Font8x12	8	12	3		15
	Font8x14	8	14	3		17
	Font8x16	8	16	3		19
	Font12x22	12	22	4		26	     ASCII only
	===============	=======	=======	===============	============ ==========

	Widths and heights are given in number of pixels. Extra height is the room reserved for the underline (cursor).

.. c:macro:: DEFAULT_FONT

	This macro defines the default system font, which is normally ``Font8x16``. The default setting can be overwritten with the system option ``DEFAULT_FONT``.

CCharGenerator
^^^^^^^^^^^^^^

.. code-block:: cpp

	#include <circle/chargenerator.h>

.. cpp:class:: CCharGenerator

	This class provides easy access to system fonts.

.. cpp:function:: CCharGenerator::CCharGenerator (const TFont &rFont = DEFAULT_FONT, TFontFlags Flags = FontFlagsNone)

	Creates an instance of `CCharGenerator`. ``rFont`` is the font descriptor of the font to be used. ``Flags`` modifies the font with the following possible options:

.. cpp:enum:: CCharGenerator::TFontFlags

	* FontFlagsNone
	* FontFlagsDoubleWidth
	* FontFlagsDoubleHeight
	* FontFlagsDoubleBoth

.. cpp:function:: static CCharGenerator::TFontFlags CCharGenerator::MakeFlags (boolean bDoubleWidth, boolean bDoubleHeight)

	Makes font flags from separate options.

.. cpp:function:: unsigned CCharGenerator::GetCharWidth (void) const

	Returns the horizontal number of pixels per character.

.. cpp:function:: unsigned CCharGenerator::GetCharHeight (void) const

	Returns the vertical number of pixels per character including the underline space.

.. cpp:function:: unsigned CCharGenerator::GetUnderline (void) const

	Returns the vertical pixel start line of the underline space.

.. cpp:function:: CCharGenerator::TPixelLine CCharGenerator::GetPixelLine (char chAscii, unsigned nPosY) const

	Returns the horizontal pixel information for character code (normally ISO-8859-1) ``chAscii`` for the pixel line ``nPosY`` inside the character (0-based) as the following type:

.. cpp:type:: CCharGenerator::TPixelLine

.. cpp:function:: boolean CCharGenerator::GetPixel (unsigned nPosX, TPixelLine Line) const

	Returns ``TRUE``, if the pixel at the horizontal position ``nPosX`` (left is 0) is set inside the pixel line ``Line``, which has been fetched using :cpp:func:`CCharGenerator::GetPixelLine()`.

.. cpp:function:: boolean CCharGenerator::GetPixel (char chAscii, unsigned nPosX, unsigned nPosY) const

	Returns ``TRUE``, if the pixel at the horizontal position ``nPosX`` (left is 0) and vertical position ``nPosY`` (0-based) is set for character code (normally ISO-8859-1) ``chAscii``.