Coverage Maps

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);

Increase 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.