GDK Reference Manual

　　Returns : the X error code, or 0 if no error occurred.

　　Points, Rectangles and Regions

　　Name

　　Points, Rectangles and Regions -- simple graphical data types.

　　Synopsis

#include <gdk/gdk.h>
structGdkPoint;
structGdkRectangle;
gintgdk_rectangle_intersect (GdkRectangle *src1,
GdkRectangle *src2,GdkRectangle *dest);
voidgdk_rectangle_union (GdkRectangle *src1,
GdkRectangle *src2,GdkRectangle *dest);
structGdkRegion;
GdkRegion*gdk_region_new(void);
GdkRegion*gdk_region_polygon(GdkPoint *points,
gint npoints,GdkFillRule fill_rule);
enumGdkFillRule;
voidgdk_region_destroy(GdkRegion *region);
GdkRegion*gdk_regions_intersect (GdkRegion *source1,GdkRegion *source2);
GdkRegion*gdk_regions_union (GdkRegion *source1,GdkRegion *source2);
GdkRegion*gdk_regions_subtract(GdkRegion *source1,GdkRegion *source2);
GdkRegion*gdk_regions_xor (GdkRegion *source1,GdkRegion *source2);
GdkRegion*gdk_region_union_with_rect(GdkRegion *region,GdkRectangle *rect);
voidgdk_region_offset (GdkRegion *region,gint dx,gint dy);
voidgdk_region_shrink (GdkRegion *region,gint dx,gint dy);
gbooleangdk_region_empty(GdkRegion *region);
gbooleangdk_region_equal(GdkRegion *region1,GdkRegion *region2);
gbooleangdk_region_point_in (GdkRegion *region,int x,int y);
GdkOverlapType gdk_region_rect_in (GdkRegion *region,GdkRectangle *rect);
enumGdkOverlapType;
voidgdk_region_get_clipbox(GdkRegion *region,GdkRectangle *rectangle); 

　　Description

　　GDK provides the GdkPoint, GdkRectangle and GdkRegion data types for representing pixels and sets of pixels on the screen.

　　GdkPoint is a simple structure containing an x and y coordinate of a point.

　　GdkRectangle is a structure holding the position and size of a rectangle. The intersection of two rectangles can be computed with gdk_rectangle_intersect(). To find the union of two rectangles use gdk_rectangle_union().

　　GdkRegion is an opaque data type holding a set of arbitrary pixels, and is usually used for clipping graphical operations (see gdk_gc_set_clip_region()).

　　Details

　　struct GdkPoint

struct GdkPoint
{
gint16 x;
gint16 y;
}; 

　　Defines the x and y coordinates of a point. Note that both are defined as gint16 values, so the coordinates are limited to between -32,768 and 32,767.

　　gint16 x the x coordinate of the point.

　　gint16 y the y coordinate of the point.

　　struct GdkRectangle

struct GdkRectangle
{
gint16 x;
gint16 y;
guint16 width;
guint16 height;
}; 

　　Defines the position and size of a rectangle.

　　gint16 x the x coordinate of the left edge of the rectangle.

　　gint16 y the y coordinate of the top of the rectangle.

　　guint16 width the width of the rectangle.

　　guint16 height the height of the rectangle.

gdk_rectangle_intersect ()
gintgdk_rectangle_intersect (GdkRectangle *src1,
GdkRectangle *src2,GdkRectangle *dest); 

　　Calculates the intersection of two rectangles.

　　src1 : a GdkRectangle.

　　src2 : a GdkRectangle.

　　dest : the intersection of src1 and src2.

　　Returns : TRUE if the rectangles intersect.

gdk_rectangle_union ()
voidgdk_rectangle_union (GdkRectangle *src1,
GdkRectangle *src2,GdkRectangle *dest); 

　　Calculates the union of two rectangles. The union of rectangles src1 and src2 is the smallest rectangle which includes both src1 and src2 within it.

　　src1 : a GdkRectangle.

　　src2 : a GdkRectangle.

　　dest : the union of src1 and src2.

　　struct GdkRegion

struct GdkRegion
{
gpointer user_data;
}; 

　　A GdkRegion represents a set of pixels on the screen. The only user-visible field of the structure is the user_data member, which can be used to attach arbitrary data to the GdkRegion.

　　gpointer user_data arbitrary data attached to the GdkRegion.

gdk_region_new ()
GdkRegion*gdk_region_new(void); 

　　Creates a new empty GdkRegion.

　　Returns : a new empty GdkRegion.