NAME
	libglitter - Subpixel-rendering library

DESCRIPTION
	libglitter is a C library for subpixel-rendered text from an
	greyscale-antialiased text image. libglitter is designed to be
	used in conjunction with other font libraries: it can neither
	rasterise glyphs nor does it know about the montor's subpixel
	layout or rendering configurations.

	To use libglitter you first apply hinting to the text so that
	the glyph outlines aligns with the output's pixel-grid as
	closely as possible. The next step is to get the output's
	subpixel arrangement and scaling factor, then assuming that
	the output's subpixel arrangement is subpixel-rendering
	compatible and that its native resolution is used, you
	rasterise the text using greyscale-antialiasing into a raster
	sized according to the output's horizontal and vertical
	subpixel densities (rather than pixel densities as normally
	done with greyscale-antialiasing; some subpixels may have be
	counted multiple times depending on the subpixel arrangement).
	After this you create an uninitialised colour raster for text
	and the output's pixel density, and split it into one raster
	per colour channel using libglitter_split_uint64_raster(3) or
	libglitter_split_uint32_raster(3), this is when libglitter is
	first used in this process; alternatively you create one
	raster for each colour channel directly. Then you use
	libglitter_compose_double(3), libglitter_compose_float(3),
	libglitter_compose_uint64(3), libglitter_compose_uint32(3),
	libglitter_compose_uint16(3), or libglitter_compose_uint8(3)
	to create the subpixel-antialiased image of the text; you may
	have to first call libglitter_reorder_rasters(3) to put the
	rasters in the expected order.

	An optional next step is to use lessen the intensity of the
	subpixel-antialiasing with libglitter_desaturate_double(3),
	libglitter_desaturate_float(3), libglitter_per_channel_-
	desaturate_double(3), or libglitter_per_channel_desaturate_-
	float(3).

	Then, if the application cannot output directly to the
	output's colour space, the application can use
	libglitter_get_colour_space_conversion_matrix_double(3)
	and libglitter_colour_space_convert_rasters_double(3) or
	libglitter_get_colour_space_conversion_matrix_float(3)
	and libglitter_colour_space_convert_rasters_float(3) to
	convert a colour space the application can output in. It is
	however out of the scope of libglitter to get the output's
	colour space and the conversion matrix to any other colour
	space than sRGB or CIE XYZ.

	The finally step of the rendering process is out of scope for
	libglitter, but is to ensure that all floating-point values
	(if floating-point rasters are used) are withing [0, 1] and
	convert the rasters, which only contain ink-on intensities,
	into the desired colour's with the output's transfer function
	applied.

	The application may also desire to call libglitter_enable_-
	acceleration(3) at the beginning of its execution to enable
	any implemented and supported hardware acceleration. This
	may however be an expensive process, and may not be
	desirable for all applications.

SEE ALSO
	libfonts(7)