|  |  |  | Pango Reference Manual |  | 
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| PangoEngineShapePangoEngineShape — Rendering-system dependent script engines | 
            PangoEngineShape;
            PangoEngineShapeClass;
#define     PANGO_ENGINE_TYPE_SHAPE
#define     PANGO_ENGINE_SHAPE_DEFINE_TYPE  (name, prefix, class_init, instance_init)
typedef struct _PangoEngineShape PangoEngineShape;
The PangoEngineShape class is implemented by engines that customize the rendering-system dependent part of the Pango pipeline for a particular script or language. A PangoEngineShape implementation is then specific to both a particular rendering system or group of rendering systems and to a particular script. For instance, there is one PangoEngineShape implementation to handling shaping Arabic for Fontconfig-based backends.
typedef struct {
  void (*script_shape) (PangoEngineShape *engine,
			PangoFont        *font,
			const char       *text,
			int               length,
			PangoAnalysis    *analysis,
			PangoGlyphString *glyphs);
  PangoCoverageLevel (*covers)   (PangoEngineShape *engine,
				  PangoFont        *font,
				  PangoLanguage    *language,
				  gunichar          wc);
} PangoEngineShapeClass;
Class structure for PangoEngineShape
| script_shape () | Given a font, a piece of text, and a PangoAnalysis structure, converts characters to glyphs and positions the resulting glyphs. The results are stored in the PangoGlyphString that is passed in. (The implementation should resize it appropriately using pango_glyph_string_set_size()). All fields of the log_clusters and glyphs array must be filled in, with the exception that Pango will automatically generate glyphs->glyphs[i].attr.is_cluster_start using the log_clusters array. Each input character must occur in one of the output logical clusters; if no rendering is desired for a character, this may involve inserting glyphs with the PangoGlyph ID 0, which is guaranteed never to render. | 
| covers () | Returns the characters that this engine can cover with a given font for a given language. If not overridden, the default implementation simply returns the coverage information for the font itself unmodified. | 
#define PANGO_ENGINE_TYPE_SHAPE "PangoEngineShape"
A string constant defining the engine type for shaping engines. These engines derive from PangoEngineShape.
#define PANGO_ENGINE_SHAPE_DEFINE_TYPE(name, prefix, class_init, instance_init)
Outputs the necessary code for GObject type registration for a PangoEngineShape class defined in a module. Two static symbols are defined.
static GType prefix_type; static void prefix_register_type (GTypeModule module);
The prefix, _register_type() function should be called in your script_engine_init() function for each type that your module implements, and then your script_engine_create() function can create instances of the object as follows:
PangoEngine *engine = g_object_new (prefix_type, NULL);
| name : | Name of the the type to register (for example:, ArabicEngineFc | 
| prefix : | Prefix for symbols that will be defined (for example:, arabic_engine_fc | 
| class_init : | Class initialization function for the new type, or NULL | 
| instance_init : | Instance initialization function for the new type, or NULL | 
| << PangoEngineLang | Modules >> |