gnome-canvas-path-def

gnome-canvas-path-def — Container and functions for manipulating ArtBpaths

Synopsis

#include <libgnomecanvas/libgnomecanvas.h>

                    GnomeCanvasPathDef;
GnomeCanvasPathDef *  gnome_canvas_path_def_new         (void);
GnomeCanvasPathDef *  gnome_canvas_path_def_new_sized   (gint length);
GnomeCanvasPathDef *  gnome_canvas_path_def_new_from_bpath
                                                        (ArtBpath *bpath);
GnomeCanvasPathDef *  gnome_canvas_path_def_new_from_static_bpath
                                                        (ArtBpath *bpath);
GnomeCanvasPathDef *  gnome_canvas_path_def_new_from_foreign_bpath
                                                        (ArtBpath *bpath);
void                gnome_canvas_path_def_ref           (GnomeCanvasPathDef *path);
void                gnome_canvas_path_def_finish        (GnomeCanvasPathDef *path);
void                gnome_canvas_path_def_ensure_space  (GnomeCanvasPathDef *path,
                                                         gint space);
void                gnome_canvas_path_def_copy          (GnomeCanvasPathDef *dst,
                                                         const GnomeCanvasPathDef *src);
GnomeCanvasPathDef *  gnome_canvas_path_def_duplicate   (const GnomeCanvasPathDef *path);
GnomeCanvasPathDef *  gnome_canvas_path_def_concat      (const GSList *list);
GSList *            gnome_canvas_path_def_split         (const GnomeCanvasPathDef *path);
GnomeCanvasPathDef *  gnome_canvas_path_def_open_parts  (const GnomeCanvasPathDef *path);
GnomeCanvasPathDef *  gnome_canvas_path_def_closed_parts
                                                        (const GnomeCanvasPathDef *path);
GnomeCanvasPathDef *  gnome_canvas_path_def_close_all   (const GnomeCanvasPathDef *path);
void                gnome_canvas_path_def_unref         (GnomeCanvasPathDef *path);
void                gnome_canvas_path_def_reset         (GnomeCanvasPathDef *path);
void                gnome_canvas_path_def_moveto        (GnomeCanvasPathDef *path,
                                                         gdouble x,
                                                         gdouble y);
void                gnome_canvas_path_def_lineto        (GnomeCanvasPathDef *path,
                                                         gdouble x,
                                                         gdouble y);
void                gnome_canvas_path_def_lineto_moving (GnomeCanvasPathDef *path,
                                                         gdouble x,
                                                         gdouble y);
void                gnome_canvas_path_def_curveto       (GnomeCanvasPathDef *path,
                                                         gdouble x0,
                                                         gdouble y0,
                                                         gdouble x1,
                                                         gdouble y1,
                                                         gdouble x2,
                                                         gdouble y2);
void                gnome_canvas_path_def_closepath     (GnomeCanvasPathDef *path);
void                gnome_canvas_path_def_closepath_current
                                                        (GnomeCanvasPathDef *path);
ArtBpath *          gnome_canvas_path_def_bpath         (const GnomeCanvasPathDef *path);
gint                gnome_canvas_path_def_length        (const GnomeCanvasPathDef *path);
gboolean            gnome_canvas_path_def_is_empty      (const GnomeCanvasPathDef *path);
gboolean            gnome_canvas_path_def_has_currentpoint
                                                        (const GnomeCanvasPathDef *path);
void                gnome_canvas_path_def_currentpoint  (const GnomeCanvasPathDef *path,
                                                         ArtPoint *p);
ArtBpath *          gnome_canvas_path_def_last_bpath    (const GnomeCanvasPathDef *path);
ArtBpath *          gnome_canvas_path_def_first_bpath   (const GnomeCanvasPathDef *path);
gboolean            gnome_canvas_path_def_any_open      (const GnomeCanvasPathDef *path);
gboolean            gnome_canvas_path_def_all_open      (const GnomeCanvasPathDef *path);
gboolean            gnome_canvas_path_def_any_closed    (const GnomeCanvasPathDef *path);
gboolean            gnome_canvas_path_def_all_closed    (const GnomeCanvasPathDef *path);

Object Hierarchy

  GBoxed
   +----GnomeCanvasPathDef

Description

Convenient container and functions for manipulating ArtBpaths, which are paths defined by line and curve segments.

Details

GnomeCanvasPathDef

typedef struct _GnomeCanvasPathDef GnomeCanvasPathDef;

This structure should not be accessed directly. Use the functions defined below.


gnome_canvas_path_def_new ()

GnomeCanvasPathDef *  gnome_canvas_path_def_new         (void);

This function creates a new empty gnome_canvas_path_def.

Returns :

the new canvas path definition.

gnome_canvas_path_def_new_sized ()

GnomeCanvasPathDef *  gnome_canvas_path_def_new_sized   (gint length);

This function creates a new gnome_canvas_path_def with length number of points allocated. It is useful, if you know the exact number of points in path, so you can avoid automatic point array reallocation.

length :

number of points to allocate for the path

Returns :

the new canvas path definition

gnome_canvas_path_def_new_from_bpath ()

GnomeCanvasPathDef *  gnome_canvas_path_def_new_from_bpath
                                                        (ArtBpath *bpath);

This function constructs a new gnome_canvas_path_def and uses the passed bpath as the contents. The passed bpath should not be static as the path definition is editable when constructed with this function. Also, passed bpath will be freed with art_free, if path is destroyed, so use it with caution. For constructing a gnome_canvas_path_def from (non-modifiable) bpath use gnome_canvas_path_def_new_from_static_bpath.

bpath :

libart bezier path

Returns :

the new canvas path definition that is populated with the passed bezier path, if the bpath is bad NULL is returned.

gnome_canvas_path_def_new_from_static_bpath ()

GnomeCanvasPathDef *  gnome_canvas_path_def_new_from_static_bpath
                                                        (ArtBpath *bpath);

This function constructs a new gnome_canvas_path_def and references the passed bpath as its contents. The gnome_canvas_path_def returned from this function is to be considered static and non-editable (meaning you cannot change the path from what you passed in bpath). The bpath will not be freed, if path will be destroyed, so use it with caution.

bpath :

libart bezier path

Returns :

the new canvas path definition that references the passed bpath, or if the path is bad NULL is returned.

gnome_canvas_path_def_new_from_foreign_bpath ()

GnomeCanvasPathDef *  gnome_canvas_path_def_new_from_foreign_bpath
                                                        (ArtBpath *bpath);

This function constructs a new gnome_canvas_path_def and duplicates the contents of the passed bpath in the definition.

bpath :

libart bezier path

Returns :

the newly created gnome_canvas_path_def or NULL if the path is invalid.

gnome_canvas_path_def_ref ()

void                gnome_canvas_path_def_ref           (GnomeCanvasPathDef *path);

Increment the reference count of the GnomeCanvasPathDef.

path :

a GnomeCanvasPathDef

gnome_canvas_path_def_finish ()

void                gnome_canvas_path_def_finish        (GnomeCanvasPathDef *path);

Trims dynamic point array to exact length of path.

path :

a GnomeCanvasPathDef

gnome_canvas_path_def_ensure_space ()

void                gnome_canvas_path_def_ensure_space  (GnomeCanvasPathDef *path,
                                                         gint space);

This function ensures that enough space for space points is allocated at the end of the path.

path :

a GnomeCanvasPathDef

space :

number of points to guarantee are allocated at the end of the path.

gnome_canvas_path_def_copy ()

void                gnome_canvas_path_def_copy          (GnomeCanvasPathDef *dst,
                                                         const GnomeCanvasPathDef *src);

This function copies the contents src to dest. The old dest path array is freed and dest is marked as non-static (editable), regardless of the status of src.

dst :

a GnomeCanvasPathDef where the contents of src will be stored.

src :

a GnomeCanvasPathDef whose contents will be copied it src.

gnome_canvas_path_def_duplicate ()

GnomeCanvasPathDef *  gnome_canvas_path_def_duplicate   (const GnomeCanvasPathDef *path);

This function duplicates the passed path. The new path is marked as non-static regardless of the state of original.

path :

a GnomeCanvasPathDef to duplicate

Returns :

a GnomeCanvasPathDef which is a duplicate of path.

gnome_canvas_path_def_concat ()

GnomeCanvasPathDef *  gnome_canvas_path_def_concat      (const GSList *list);

This function concatenates a list of GnomeCanvasPathDefs into one newly created GnomeCanvasPathDef.

list :

a GSList of GnomeCanvasPathDefs to concatenate into one new path.

Returns :

a new GnomeCanvasPathDef

gnome_canvas_path_def_split ()

GSList *            gnome_canvas_path_def_split         (const GnomeCanvasPathDef *path);

This function splits the passed path into a list of GnomeCanvasPathDefs which represent each segment of the origional path. The path is split when ever an ART_MOVETO or ART_MOVETO_OPEN is encountered. The closedness of resulting paths is set accordingly to closedness of corresponding segment.

path :

a GnomeCanvasPathDef

Returns :

a list of GnomeCanvasPathDef(s).

gnome_canvas_path_def_open_parts ()

GnomeCanvasPathDef *  gnome_canvas_path_def_open_parts  (const GnomeCanvasPathDef *path);

This function creates a new GnomeCanvasPathDef that contains all of the open segments on the passed path.

path :

a GnomeCanvasPathDef

Returns :

a new GnomeCanvasPathDef that contains all of the open segemtns in path.

gnome_canvas_path_def_closed_parts ()

GnomeCanvasPathDef *  gnome_canvas_path_def_closed_parts
                                                        (const GnomeCanvasPathDef *path);

This function returns a new GnomeCanvasPathDef that contains the all of close parts of passed path.

path :

a GnomeCanvasPathDef

Returns :

a new GnomeCanvasPathDef that contains all of the closed parts of passed path.

gnome_canvas_path_def_close_all ()

GnomeCanvasPathDef *  gnome_canvas_path_def_close_all   (const GnomeCanvasPathDef *path);

This function closes all of the open segments in the passed path and returns a new GnomeCanvasPathDef.

path :

a GnomeCanvasPathDef

Returns :

a GnomeCanvasPathDef that contains the contents of path but has modified the path is fully closed

gnome_canvas_path_def_unref ()

void                gnome_canvas_path_def_unref         (GnomeCanvasPathDef *path);

Decrease the reference count of the passed path. If the reference count is < 1 the path is deallocated.

path :

a GnomeCanvasPathDef

gnome_canvas_path_def_reset ()

void                gnome_canvas_path_def_reset         (GnomeCanvasPathDef *path);

This function clears the contents of the passed path.

path :

a GnomeCanvasPathDef

gnome_canvas_path_def_moveto ()

void                gnome_canvas_path_def_moveto        (GnomeCanvasPathDef *path,
                                                         gdouble x,
                                                         gdouble y);

This function adds starts new subpath on path, and sets its starting point to x and y. If current subpath is empty, it simply changes its starting coordinates to new values.

path :

a GnomeCanvasPathDef

x :

x coordinate

y :

y coordinate

gnome_canvas_path_def_lineto ()

void                gnome_canvas_path_def_lineto        (GnomeCanvasPathDef *path,
                                                         gdouble x,
                                                         gdouble y);

This function add a line segment to the passed path with the specified x and y coordinates.

path :

a GnomeCanvasPathDef

x :

x coordinate

y :

y coordinate

gnome_canvas_path_def_lineto_moving ()

void                gnome_canvas_path_def_lineto_moving (GnomeCanvasPathDef *path,
                                                         gdouble x,
                                                         gdouble y);

This functions adds a new line segment with loose endpoint to the path, or if endpoint is already loose, changes its coordinates to x, y. You can change the coordinates of loose endpoint as many times as you want, the last ones set will be fixed, if you continue line. This is useful for handling drawing with mouse.

path :

a GnomeCanvasPathDef

x :

x coordinate

y :

y coordinate

gnome_canvas_path_def_curveto ()

void                gnome_canvas_path_def_curveto       (GnomeCanvasPathDef *path,
                                                         gdouble x0,
                                                         gdouble y0,
                                                         gdouble x1,
                                                         gdouble y1,
                                                         gdouble x2,
                                                         gdouble y2);

This function adds a bezier curve segment to the path definition.

path :

a GnomeCanvasPathDef

x0 :

first control point x coordinate

y0 :

first control point y coordinate

x1 :

second control point x coordinate

y1 :

second control point y coordinate

x2 :

end of curve x coordinate

y2 :

end of curve y coordinate

gnome_canvas_path_def_closepath ()

void                gnome_canvas_path_def_closepath     (GnomeCanvasPathDef *path);

This function closes the last subpath of path, adding a ART_LINETO to subpath starting point, if needed and changing starting pathcode to ART_MOVETO

path :

a GnomeCanvasPathDef

gnome_canvas_path_def_closepath_current ()

void                gnome_canvas_path_def_closepath_current
                                                        (GnomeCanvasPathDef *path);

This function closes the last subpath by setting the coordinates of the endpoint of the last segment (line or curve) to starting point.

path :

a GnomeCanvasPathDef

gnome_canvas_path_def_bpath ()

ArtBpath *          gnome_canvas_path_def_bpath         (const GnomeCanvasPathDef *path);

This function returns a ArtBpath that consists of the path definition.

path :

a GnomeCanvasPathDef

Returns :

ArtBpath

gnome_canvas_path_def_length ()

gint                gnome_canvas_path_def_length        (const GnomeCanvasPathDef *path);

This function returns the length of the path definition. Not Euclidian length of the path but rather the number of points on the path.

path :

a GnomeCanvasPathDef

Returns :

integer, number of points on the path.

gnome_canvas_path_def_is_empty ()

gboolean            gnome_canvas_path_def_is_empty      (const GnomeCanvasPathDef *path);

This function is a boolean test to see if the path is empty, meaning containing no line segments.

path :

a GnomeCanvasPathDef

Returns :

boolean, indicating if the path is empty.

gnome_canvas_path_def_has_currentpoint ()

gboolean            gnome_canvas_path_def_has_currentpoint
                                                        (const GnomeCanvasPathDef *path);

This function is a boolean test checking to see if the path has a current point defined. Current point will be set by line operators, and cleared by closing subpath.

path :

a GnomeCanvasPathdef

Returns :

boolean, indicating if the path has a current point defined.

gnome_canvas_path_def_currentpoint ()

void                gnome_canvas_path_def_currentpoint  (const GnomeCanvasPathDef *path,
                                                         ArtPoint *p);

Stores the current point of the path definition in the passed ArtPoint p.

path :

a GnomeCanvasPathDef

p :

a ArtPoint where to store the current point

gnome_canvas_path_def_last_bpath ()

ArtBpath *          gnome_canvas_path_def_last_bpath    (const GnomeCanvasPathDef *path);

This function returns pointer to the last ArtBpath segment in the path definition.

path :

a GnomeCanvasPathDef

Returns :

ArtBpath, being the last segment in the path definition or null if no line segments have been defined.

gnome_canvas_path_def_first_bpath ()

ArtBpath *          gnome_canvas_path_def_first_bpath   (const GnomeCanvasPathDef *path);

This function returns the first ArtBpath point in the definition.

path :

a GnomeCanvasPathDef

Returns :

ArtBpath being the first point in the path definition or null if no points are defined

gnome_canvas_path_def_any_open ()

gboolean            gnome_canvas_path_def_any_open      (const GnomeCanvasPathDef *path);

This function returns a boolean value indicating if the path has any open segments.

path :

a GnomeCanvasPathDef

Returns :

boolean, indicating if the path has any open segments.

gnome_canvas_path_def_all_open ()

gboolean            gnome_canvas_path_def_all_open      (const GnomeCanvasPathDef *path);

This function returns a boolean value indicating if the path only contains open segments.

path :

a GnomeCanvasPathDef

Returns :

boolean, indicating if the path has all open segments.

gnome_canvas_path_def_any_closed ()

gboolean            gnome_canvas_path_def_any_closed    (const GnomeCanvasPathDef *path);

This function returns a boolean valid indicating if the path has any closed segements.

path :

a GnomeCanvasPathDef

Returns :

boolean, indicating if the path has any closed segments.

gnome_canvas_path_def_all_closed ()

gboolean            gnome_canvas_path_def_all_closed    (const GnomeCanvasPathDef *path);

This function returns a boolean value indicating if the path only contains closed segments.

path :

a GnomeCanvasPathDef

Returns :

boolean, indicating if the path has all closed segments.