|  |  |  | Goffice Reference Manual |  | 
|---|---|---|---|---|
#define GO_GEOMETRY_ANGLE_TOLERANCE enum GOGeometrySide; enum GODirection; enum GOGeometryRotationType; GOGeometryOBR; #define GOGeometryAABR void go_geometry_cartesian_to_polar (double x, double y, double *rho, double *theta); double go_geometry_point_to_segment (double xp, double yp, double xs, double ys, double w, double h); void go_geometry_AABR_add (GOGeometryAABR *aabr0, GOGeometryAABR const *aabr1); void go_geometry_OBR_to_AABR (GOGeometryOBR const *obr, GOGeometryAABR *aabr); gboolean go_geometry_test_OBR_overlap (GOGeometryOBR const *obr0, GOGeometryOBR const *obr1); GOGeometryRotationType go_geometry_get_rotation_type (double alpha); GOGeometrySide go_geometry_calc_label_anchor (GOGeometryOBR *obr, double alpha); GOGeometrySide go_geometry_calc_label_position (GOGeometryOBR *obr, double alpha, double offset, GOGeometrySide side, GOGeometrySide anchor); #define GO_DIRECTION_TYPE GType go_direction_get_type (void); gboolean go_direction_is_horizontal (GODirection d); gboolean go_direction_is_forward (GODirection d);
typedef enum {
	GO_SIDE_LEFT		= 1 << 0,
	GO_SIDE_RIGHT		= 1 << 1,
	GO_SIDE_LEFT_RIGHT	= 3 << 0,
	GO_SIDE_TOP		= 1 << 2,
	GO_SIDE_BOTTOM		= 1 << 3,
	GO_SIDE_TOP_BOTTOM	= 3 << 2,
	GO_SIDE_AUTO		= 15
} GOGeometrySide;
typedef enum {
	GO_DIRECTION_UP    = 0,	
	GO_DIRECTION_DOWN  = 1,
	GO_DIRECTION_LEFT  = 2,
	GO_DIRECTION_RIGHT = 3,
	GO_DIRECTION_NONE  = 4
} GODirection;
typedef enum {
	GO_ROTATE_NONE = 0,
	GO_ROTATE_COUNTERCLOCKWISE = 1,
	GO_ROTATE_UPSIDEDOWN = 2,
	GO_ROTATE_CLOCKWISE = 3,	
	GO_ROTATE_FREE = 4
} GOGeometryRotationType;
typedef struct {
        double x,y;     /* Center */
        double w,h;     /* Edges */
        double alpha;   /* Angle from x axis to w edge, in radians */
} GOGeometryOBR;
void                go_geometry_cartesian_to_polar      (double x,
                                                         double y,
                                                         double *rho,
                                                         double *theta);
Converts cartesion coordinates to polar coordinates.
| 
 | cartesian coordinate | 
| 
 | cartesian coordinate | 
| 
 | polar coordinate | 
| 
 | polar coordinate | 
double              go_geometry_point_to_segment        (double xp,
                                                         double yp,
                                                         double xs,
                                                         double ys,
                                                         double w,
                                                         double h);
| 
 | point coordinate | 
| 
 | point coordinate | 
| 
 | segment start coordinate | 
| 
 | segment start coordinate | 
| 
 | extent of segment | 
| 
 | extent of segment | 
| Returns : | the distance between a point and a segment. | 
void go_geometry_AABR_add (GOGeometryAABR *aabr0, GOGeometryAABR const *aabr1);
Computes the Axis Aligned Bounding Rectangle of aabr0 and aabr1, and stores result in aabr0.
| 
 | a GOGeometryAABR | 
| 
 | a GOGeometryAABR | 
void go_geometry_OBR_to_AABR (GOGeometryOBR const *obr, GOGeometryAABR *aabr);
Stores Axis Aligned Bouding Rectangle of obr in aabr.
| 
 | a GOGeometryOBR | 
| 
 | a GOGeometryAABR | 
gboolean go_geometry_test_OBR_overlap (GOGeometryOBR const *obr0, GOGeometryOBR const *obr1);
Overlap test of Oriented Bounding Rectangles by the separating axis method.
| 
 | a GOGeometryOBR | 
| 
 | a GOGeometryOBR | 
| Returns : | TRUEif OOBRs overlap | 
GOGeometryRotationType go_geometry_get_rotation_type (double alpha);
Calculates rotation type for handling of special angles (alpha = n * pi / 2)
| 
 | angle in radians | 
| Returns : | a GOGeometryRotationType | 
GOGeometrySide go_geometry_calc_label_anchor (GOGeometryOBR *obr, double alpha);
| 
 | bounding rectangle of label | 
| 
 | angle of axis | 
| Returns : | computed label anchor, to be used by go_geometry_calc_label_position. | 
GOGeometrySide go_geometry_calc_label_position (GOGeometryOBR *obr, double alpha, double offset, GOGeometrySide side, GOGeometrySide anchor);
Convenience routine that computes position of a label relative to an axis.
| 
 | bounding rectangle of label | 
| 
 | angle of axis | 
| 
 | minimum distance between label and axis | 
| 
 | side of label with respect to axis | 
| 
 | where to anchor the label | 
| Returns : | the computed anchor if anchor== GO_SIDE_AUTO, oranchorvalue. | 
gboolean go_direction_is_horizontal (GODirection d);
| 
 | GODirection | 
| Returns : | TRUE for GO_DIRECTION_LEFT and GO_DIRECTION_RIGHT. | 
gboolean go_direction_is_forward (GODirection d);
| 
 | GODirection | 
| Returns : | TRUE for GO_DIRECTION_DOWN or GO_DIRECTION_RIGHT. |