path: root/README

NAME
	librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket - Font rasterisation library

DESCRIPTION
	librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket is a C library
	for converting shape outlines to filled shapes, with a focus on fonts, which
	that it only supports filled, closed shapes and that the direction of the
	outline determines whether a shape adds or subtracts to the image (the absolute
	values of the result is used in the image). Furthermore this means that the
	library only supports curve types that are used for drawing glyphs; specifically
	this means that lines and quadratic Bézier curves are supported by cause this
	is what is requied to draw vectorised bitmap fonts and TrueType fonts, but also
	cubic Bézier curves as this is required for OpenType fonts and elliptical arcs
	(elliptical rather than circular because it may be need required to strech the
	circle to support outputs with different vertical and horizontal dot density
	and to support subpixel antialiasing) as this is commonly used for corners when
	stroking the outline of a glyph.

	The create an image, first create a buffer using rtgrpblib_create_raster(3)
	(if you already have one that is large enough, you can reinitialise it with
	rtgrpblib_reset_raster(3)), and than using the drawing functions
	(rtgrpblib_draw_linear_bezier(3), rtgrpblib_draw_quadratic_bezier(3),
	rtgrpblib_draw_cubic_bezier(3), and rtgrpblib_draw_elliptical_arc(3)) to
	draw the components of each shape's outline. When done, create an image
	using the rtgrpblib_fill_shapes(3) function: you will receive a ink-level
	map, where the value 0 means background, and 1 means foreground, and values
	between are colours between (no transfer function is applied).

NOTES
	Rifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket (hyphenation:
	ri|funk¦tions-tec¦ken|snit¦ts-glyf-ras¦ter¦iser¦ings-prog¦ram|bib¦lio¦te¦ket)
	is Swedish for "the library for rasterising glyphs from spline fonts".

	Because of the length of the library name, and length limitation on function
	names, the functions in this library are namespaced with the prefix "rtgrpblib_".