Coverage Maps: Pango Reference Manual

Coverage Maps

Coverage Maps — Unicode character range coverage storage

Functions

#define	PANGO_TYPE_COVERAGE_LEVEL
PangoCoverage *	pango_coverage_new ()
PangoCoverage *	pango_coverage_ref ()
void	pango_coverage_unref ()
PangoCoverage *	pango_coverage_copy ()
PangoCoverageLevel	pango_coverage_get ()
void	pango_coverage_max ()
void	pango_coverage_set ()
void	pango_coverage_to_bytes ()
PangoCoverage *	pango_coverage_from_bytes ()

Types and Values

enum	PangoCoverageLevel
	PangoCoverage

Object Hierarchy

    GEnum
    ╰── PangoCoverageLevel

Description

It is often necessary in Pango to determine if a particular font can represent a particular character, and also how well it can represent that character. The PangoCoverage is a data structure that is used to represent that information.

Functions

PANGO_TYPE_COVERAGE_LEVEL

#define PANGO_TYPE_COVERAGE_LEVEL (pango_coverage_level_get_type ())

pango_coverage_new ()

PangoCoverage *
pango_coverage_new (void);

Create a new PangoCoverage

Returns

the newly allocated PangoCoverage, initialized to PANGO_COVERAGE_NONE with a reference count of one, which should be freed with pango_coverage_unref().

pango_coverage_ref ()

PangoCoverage *
pango_coverage_ref (PangoCoverage *coverage);

Increase the reference count on the PangoCoverage by one

Parameters

coverage

a PangoCoverage

Returns

coverage

pango_coverage_unref ()

void
pango_coverage_unref (PangoCoverage *coverage);

Decrease the reference count on the PangoCoverage by one. If the result is zero, free the coverage and all associated memory.

Parameters

coverage

a PangoCoverage

pango_coverage_copy ()

PangoCoverage *
pango_coverage_copy (PangoCoverage *coverage);

Copy an existing PangoCoverage. (This function may now be unnecessary since we refcount the structure. File a bug if you use it.)

Parameters

coverage

a PangoCoverage

Returns

the newly allocated PangoCoverage, with a reference count of one, which should be freed with pango_coverage_unref().

[transfer full]

pango_coverage_get ()

PangoCoverageLevel
pango_coverage_get (PangoCoverage *coverage,
                    int index_);

Determine whether a particular index is covered by coverage

Parameters

coverage	a PangoCoverage
index_	the index to check

Returns

the coverage level of coverage for character index_ .

pango_coverage_max ()

void
pango_coverage_max (PangoCoverage *coverage,
                    PangoCoverage *other);

Set the coverage for each index in coverage to be the max (better) value of the current coverage for the index and the coverage for the corresponding index in other .

Parameters

coverage	a PangoCoverage
other	another PangoCoverage

pango_coverage_set ()

void
pango_coverage_set (PangoCoverage *coverage,
                    int index_,
                    PangoCoverageLevel level);

Modify a particular index within coverage

Parameters

coverage	a PangoCoverage
index_	the index to modify
level	the new level for `index_`

pango_coverage_to_bytes ()

void
pango_coverage_to_bytes (PangoCoverage *coverage,
                         guchar **bytes,
                         int *n_bytes);

Convert a PangoCoverage structure into a flat binary format

Parameters

coverage	a PangoCoverage
bytes	location to store result (must be freed with `g_free()`).	[out][array length=n_bytes][element-type guint8]
n_bytes	location to store size of result.	[out]

pango_coverage_from_bytes ()

PangoCoverage *
pango_coverage_from_bytes (guchar *bytes,
                           int n_bytes);

Convert data generated from pango_coverage_to_bytes() back to a PangoCoverage

Parameters

bytes	binary data representing a PangoCoverage.	[array length=n_bytes][element-type guint8]
n_bytes	the size of `bytes` in bytes

Returns

a newly allocated PangoCoverage, or NULL if the data was invalid.

[transfer full][nullable]

Types and Values

enum PangoCoverageLevel

Used to indicate how well a font can represent a particular Unicode character point for a particular script.

Members

PANGO_COVERAGE_NONE	The character is not representable with the font.
PANGO_COVERAGE_FALLBACK	The character is represented in a way that may be comprehensible but is not the correct graphical form. For instance, a Hangul character represented as a a sequence of Jamos, or a Latin transliteration of a Cyrillic word.
PANGO_COVERAGE_APPROXIMATE	The character is represented as basically the correct graphical form, but with a stylistic variant inappropriate for the current script.
PANGO_COVERAGE_EXACT	The character is represented as the correct graphical form.

PangoCoverage

typedef struct _PangoCoverage PangoCoverage;

The PangoCoverage structure represents a map from Unicode characters to PangoCoverageLevel. It is an opaque structure with no public fields.