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Geocanvas Reference Manual | |
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GeoCanvasPlaceGeoCanvasPlace — a canvas group that is geo-coordinate aware. |
GeoCanvasPlacePrivate;
GeoCanvasPlace;
GeoCanvasPlaceClass;
void geo_canvas_place_request_g2w (GeoCanvasPlace *place);
The GeoCanvasPlace will automatically update itself as changes are made to the projection properties such as type, reference point, and rotation. This object is useful for plotting any simple or complex object that is reference to a single point in geographic space.
typedef struct {
FooCanvasGroupClass parent_class;
/* This is called by an idle handler but before the canvas update method
* is called. Use it to recompute geo to world mappings as required.
* When chaining-up always call the parent last to prevent
* recursive requests.
*/
void (* rebuild_g2w) (GeoCanvasPlace *place);
} GeoCanvasPlaceClass;
void geo_canvas_place_request_g2w (GeoCanvasPlace *place);
This routine sets up an idle handle. When idle, causes all geographic coordinates to be recomputed to new world coordinates. It is generally only useful to GeoCanvasPlace implementations.
place : |
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