diff options
Diffstat (limited to 'pango/pango-ot.h')
| -rw-r--r-- | pango/pango-ot.h | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/pango/pango-ot.h b/pango/pango-ot.h index cca5ef51..a27ed201 100644 --- a/pango/pango-ot.h +++ b/pango/pango-ot.h @@ -34,8 +34,35 @@ G_BEGIN_DECLS #ifdef PANGO_ENABLE_ENGINE +/** + * PangoOTTag: + * + * The #PangoOTTag typedef is used to represent TrueType and OpenType + * four letter tags inside Pango. Use PANGO_OT_TAG_MAKE() + * or PANGO_OT_TAG_MAKE_FROM_STRING() macros to create <type>PangoOTTag</type>s manually. + */ typedef guint32 PangoOTTag; +/** + * PANGO_OT_TAG_MAKE: + * @c1: First character. + * @c2: Second character. + * @c3: Third character. + * @c4: Fourth character. + * + * Creates a #PangoOTTag from four characters. This is similar and + * compatible with the <function>FT_MAKE_TAG()</function> macro from FreeType. + */ +/** + * PANGO_OT_TAG_MAKE_FROM_STRING: + * @s: The string representation of the tag. + * + * Creates a #PangoOTTag from a string. The string should be at least + * four characters long (pad with space characters if needed), and need + * not be nul-terminated. This is a convenience wrapper around + * PANGO_OT_TAG_MAKE(), but cannot be used in certain situations, for + * example, as a switch expression, as it dereferences pointers. + */ #define PANGO_OT_TAG_MAKE(c1,c2,c3,c4) ((PangoOTTag) FT_MAKE_TAG (c1, c2, c3, c4)) #define PANGO_OT_TAG_MAKE_FROM_STRING(s) (PANGO_OT_TAG_MAKE(((const char *) s)[0], \ ((const char *) s)[1], \ @@ -49,21 +76,109 @@ typedef struct _PangoOTRuleset PangoOTRuleset; typedef struct _PangoOTFeatureMap PangoOTFeatureMap; typedef struct _PangoOTRulesetDescription PangoOTRulesetDescription; +/** + * PangoOTTableType: + * @PANGO_OT_TABLE_GSUB: The GSUB table. + * @PANGO_OT_TABLE_GPOS: The GPOS table. + * + * The <type>PangoOTTableType</type> enumeration values are used to + * identify the various OpenType tables in the + * <function>pango_ot_info_*</function> functions. + */ typedef enum { PANGO_OT_TABLE_GSUB, PANGO_OT_TABLE_GPOS } PangoOTTableType; +/** + * PANGO_OT_ALL_GLYPHS: + * + * This is used as the property bit in pango_ot_ruleset_add_feature() when a + * feature should be applied to all glyphs. + * + * Since: 1.16 + */ +/** + * PANGO_OT_NO_FEATURE: + * + * This is used as a feature index that represent no feature, that is, should be + * skipped. It may be returned as feature index by pango_ot_info_find_feature() + * if the feature is not found, and pango_ot_ruleset_add_feature() function + * automatically skips this value, so no special handling is required by the user. + * + * Since: 1.18 + */ +/** + * PANGO_OT_NO_SCRIPT: + * + * This is used as a script index that represent no script, that is, when the + * requested script was not found, and a default ('DFLT') script was not found + * either. It may be returned as script index by pango_ot_info_find_script() + * if the script or a default script are not found, all other functions + * taking a script index essentially return if the input script index is + * this value, so no special handling is required by the user. + * + * Since: 1.18 + */ +/** + * PANGO_OT_DEFAULT_LANGUAGE: + * + * This is used as the language index in pango_ot_info_find_feature() when + * the default language system of the script is desired. + * + * It is also returned by pango_ot_info_find_language() if the requested language + * is not found, or the requested language tag was PANGO_OT_TAG_DEFAULT_LANGUAGE. + * The end result is that one can always call pango_ot_tag_from_language() + * followed by pango_ot_info_find_language() and pass the result to + * pango_ot_info_find_feature() without having to worry about falling back to + * default language system explicitly. + * + * Since: 1.16 + */ #define PANGO_OT_ALL_GLYPHS ((guint) 0xFFFF) #define PANGO_OT_NO_FEATURE ((guint) 0xFFFF) #define PANGO_OT_NO_SCRIPT ((guint) 0xFFFF) #define PANGO_OT_DEFAULT_LANGUAGE ((guint) 0xFFFF) +/** + * PANGO_OT_TAG_DEFAULT_SCRIPT: + * + * This is a #PangoOTTag representing the special script tag 'DFLT'. It is + * returned as script tag by pango_ot_tag_from_script() if the requested script + * is not found. + * + * Since: 1.18 + */ +/** + * PANGO_OT_TAG_DEFAULT_LANGUAGE: + * + * This is a #PangoOTTag representing a special language tag 'dflt'. It is + * returned as language tag by pango_ot_tag_from_language() if the requested + * language is not found. It is safe to pass this value to + * pango_ot_info_find_language() as that function falls back to returning default + * language-system if the requested language tag is not found. + * + * Since: 1.18 + */ #define PANGO_OT_TAG_DEFAULT_SCRIPT PANGO_OT_TAG_MAKE ('D', 'F', 'L', 'T') #define PANGO_OT_TAG_DEFAULT_LANGUAGE PANGO_OT_TAG_MAKE ('d', 'f', 'l', 't') /* Note that this must match hb_glyph_info_t */ +/** + * PangoOTGlyph: + * @glyph: the glyph itself. + * @properties: the properties value, identifying which features should be + * applied on this glyph. See pango_ot_ruleset_add_feature(). + * @cluster: the cluster that this glyph belongs to. + * @component: a component value, set by the OpenType layout engine. + * @ligID: a ligature index value, set by the OpenType layout engine. + * @internal: for Pango internal use + * + * The #PangoOTGlyph structure represents a single glyph together with + * information used for OpenType layout processing of the glyph. + * It contains the following fields. + */ struct _PangoOTGlyph { guint32 glyph; @@ -75,12 +190,46 @@ struct _PangoOTGlyph guint internal; }; +/** + * PangoOTFeatureMap: + * @feature_name: feature tag in represented as four-letter ASCII string. + * @property_bit: the property bit to use for this feature. See + * pango_ot_ruleset_add_feature() for details. + * + * The #PangoOTFeatureMap typedef is used to represent an OpenType + * feature with the property bit associated with it. The feature tag is + * represented as a char array instead of a #PangoOTTag for convenience. + * + * Since: 1.18 + */ struct _PangoOTFeatureMap { char feature_name[5]; gulong property_bit; }; +/** + * PangoOTRulesetDescription: + * @script: a #PangoScript. + * @language: a #PangoLanguage. + * @static_gsub_features: static map of GSUB features, or %NULL. + * @n_static_gsub_features: length of @static_gsub_features, or 0. + * @static_gpos_features: static map of GPOS features, or %NULL. + * @n_static_gpos_features: length of @static_gpos_features, or 0. + * @other_features: map of extra features to add to both GSUB and GPOS, or %NULL. + * Unlike the static maps, this pointer need not live beyond + * the life of function calls taking this struct. + * @n_other_features: length of @other_features, or 0. + * + * The #PangoOTRuleset structure holds all the information needed + * to build a complete #PangoOTRuleset from an OpenType font. + * The main use of this struct is to act as the key for a per-font + * hash of rulesets. The user populates a ruleset description and + * gets the ruleset using pango_ot_ruleset_get_for_description() + * or create a new one using pango_ot_ruleset_new_from_description(). + * + * Since: 1.18 + */ struct _PangoOTRulesetDescription { PangoScript script; PangoLanguage *language; |