GDK Reference Manual

　　Returns TRUE if the GdkRegion is empty.

　　region : a GdkRegion.

　　Returns : TRUE if region is empty.

gdk_region_equal ()
gbooleangdk_region_equal(GdkRegion *region1,GdkRegion *region2); 

　　Returns TRUE if the two regions are the same.

　　region1 : a GdkRegion.

　　region2 : a GdkRegion.

　　Returns : TRUE if region1 and region2 are equal.

gdk_region_point_in ()
gbooleangdk_region_point_in (GdkRegion *region,int x,int y); 

　　Returns TRUE if a point is in a region.

　　region : a GdkRegion.

　　x : the x coordinate of a point.

　　y : the y coordinate of a point.

　　Returns : TRUE if the point is in region.

gdk_region_rect_in ()
GdkOverlapType gdk_region_rect_in (GdkRegion *region,
GdkRectangle *rect); 

　　Tests whether a rectangle is within a region.

　　region : a GdkRegion.

　　rect : a GdkRectangle.

　　Returns : GDK_OVERLAP_RECTANGLE_IN, GDK_OVERLAP_RECTANGLE_OUT, or GDK_OVERLAP_RECTANGLE_PART, depending on whether the rectangle is inside, outside, or partly inside the GdkRegion, respectively.

　　enum GdkOverlapType

typedef enum
{
GDK_OVERLAP_RECTANGLE_IN,
GDK_OVERLAP_RECTANGLE_OUT,
GDK_OVERLAP_RECTANGLE_PART
} GdkOverlapType; 

　　Specifies the possible values returned by gdk_region_rect_in().

　　GDK_OVERLAP_RECTANGLE_IN if the rectangle is inside the GdkRegion.

　　GDK_OVERLAP_RECTANGLE_OUT if the rectangle is outside the GdkRegion.

　　GDK_OVERLAP_RECTANGLE_PART if the rectangle is partly inside the GdkRegion.

gdk_region_get_clipbox ()
voidgdk_region_get_clipbox(GdkRegion *region,
GdkRectangle *rectangle); 

　　Returns the smallest rectangle which includes the entire GdkRegion.

　　region : a GdkRegion.

　　rectangle : returns the smallest rectangle which includes all of region.

　　Graphics Contexts

　　Name

　　Graphics Contexts -- objects to encapsulate drawing properties.

　　Synopsis

#include <gdk/gdk.h>
structGdkGC;
structGdkGCValues;
enumGdkGCValuesMask;
enumGdkFunction;
GdkGC*gdk_gc_new(GdkWindow *window);
GdkGC*gdk_gc_new_with_values(GdkWindow *window,
GdkGCValues *values,GdkGCValuesMask values_mask);
GdkGC*gdk_gc_ref(GdkGC *gc);
voidgdk_gc_unref(GdkGC *gc);
voidgdk_gc_destroy(GdkGC *gc);
voidgdk_gc_get_values (GdkGC *gc,GdkGCValues *values);
voidgdk_gc_set_foreground (GdkGC *gc,GdkColor *color);
voidgdk_gc_set_background (GdkGC *gc,GdkColor *color);
voidgdk_gc_set_font (GdkGC *gc,GdkFont *font);
voidgdk_gc_set_function (GdkGC *gc,GdkFunction function);
voidgdk_gc_set_fill (GdkGC *gc,GdkFill fill);
enumGdkFill;
voidgdk_gc_set_tile (GdkGC *gc,GdkPixmap *tile);
voidgdk_gc_set_stipple(GdkGC *gc,GdkPixmap *stipple);
voidgdk_gc_set_ts_origin(GdkGC *gc,gint x,gint y);
voidgdk_gc_set_clip_origin(GdkGC *gc,gint x,gint y);
voidgdk_gc_set_clip_mask(GdkGC *gc,GdkBitmap *mask);
voidgdk_gc_set_clip_rectangle (GdkGC *gc,GdkRectangle *rectangle);
voidgdk_gc_set_clip_region(GdkGC *gc,GdkRegion *region);
voidgdk_gc_set_subwindow(GdkGC *gc,GdkSubwindowMode mode);
enumGdkSubwindowMode;
voidgdk_gc_set_exposures(GdkGC *gc,gint exposures);
voidgdk_gc_set_line_attributes(GdkGC *gc,gint line_width,
GdkLineStyle line_style,GdkCapStyle cap_style,GdkJoinStyle join_style);
enumGdkLineStyle;
enumGdkCapStyle;
enumGdkJoinStyle;
voidgdk_gc_set_dashes (GdkGC *gc,gint dash_offset,gchar dash_list[],gint n);
voidgdk_gc_copy (GdkGC *dst_gc,GdkGC *src_gc); 

　　Description

　　All drawing operations in GDK take a graphics context (GC) argument. A graphics context encapsulates information about the way things are drawn, such as the foreground color or line width. By using graphics contexts, the number of arguments to each drawing call is greatly reduced, and communication overhead is minimized, since identical arguments do not need to be passed repeatedly.

　　Most values of a graphics context can be set at creation time by using gdk_gc_new_with_values(), or can be set one-by-one using functions such as gdk_gc_set_foreground(). A few of the values in the GC, such as the dash pattern, can only be set by the latter method.