Coverage Maps

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Coverage Maps — Unicode character range coverage storage

Synopsis

enum                PangoCoverageLevel;
#define             PANGO_TYPE_COVERAGE_LEVEL
                    PangoCoverage;

PangoCoverage*      pango_coverage_new                  (void);
PangoCoverage*      pango_coverage_ref                  (PangoCoverage *coverage);
void                pango_coverage_unref                (PangoCoverage *coverage);
PangoCoverage*      pango_coverage_copy                 (PangoCoverage *coverage);
PangoCoverageLevel  pango_coverage_get                  (PangoCoverage *coverage,
                                                         int index_);
void                pango_coverage_max                  (PangoCoverage *coverage,
                                                         PangoCoverage *other);
void                pango_coverage_set                  (PangoCoverage *coverage,
                                                         int index_,
                                                         PangoCoverageLevel level);
void                pango_coverage_to_bytes             (PangoCoverage *coverage,
                                                         guchar **bytes,
                                                         int *n_bytes);
PangoCoverage*      pango_coverage_from_bytes           (guchar *bytes,
                                                         int n_bytes);

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.

Details

enum PangoCoverageLevel

typedef enum {
  PANGO_COVERAGE_NONE,
  PANGO_COVERAGE_FALLBACK,
  PANGO_COVERAGE_APPROXIMATE,
  PANGO_COVERAGE_EXACT
} PangoCoverageLevel;

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

`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.

PANGO_TYPE_COVERAGE_LEVEL

#define PANGO_TYPE_COVERAGE_LEVEL (pango_coverage_level_get_type())

The GObject type for PangoCoverageLevel.

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.

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

`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.

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.)

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

pango_coverage_get ()

PangoCoverageLevel  pango_coverage_get                  (PangoCoverage *coverage,
                                                         int index_);

Determine whether a particular index is covered by coverage

`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.

`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

`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

`coverage` :	a PangoCoverage
`bytes` :	location to store result (must be freed with `g_free()`)
`n_bytes` :	location to store size of result

pango_coverage_from_bytes ()

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

Convert data generated from pango_converage_to_bytes() back to a PangoCoverage

`bytes` :	binary data representing a PangoCoverage
`n_bytes` :	the size of `bytes` in bytes
Returns :	a newly allocated PangoCoverage, or `NULL` if the data was invalid.