Points, Rectangles and Regions
simple graphical data types.
GDK provides the #GdkPoint, #GdkRectangle, #GdkRegion and #GdkSpan 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()).
#GdkSpan is a structure holding a spanline. A spanline is a horizontal line that
is one pixel wide. It is mainly used when rasterizing other graphics primitives.
It can be intersected to regions by using gdk_region_spans_intersect_foreach().
@x:
@y:
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@y:
@width:
@height:
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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.
Creates a new empty #GdkRegion.
@Returns: a new empty #GdkRegion.
Creates a new #GdkRegion using the polygon defined by a number of points.
@points: an array of #GdkPoint structs.
@npoints: the number of elements in the @points array.
@fill_rule: specifies which pixels are included in the region when the polygon
overlaps itself.
@Returns: a new #GdkRegion based on the given polygon.
The method for determining which pixels are included in a region, when
creating a #GdkRegion from a polygon.
The fill rule is only relevant for polygons which overlap themselves.
@GDK_EVEN_ODD_RULE: areas which are overlapped an odd number of times are
included in the region, while areas overlapped an even number of times are not.
@GDK_WINDING_RULE: overlapping areas are always included.
@region:
@Returns:
@rectangle:
@Returns:
Destroys a #GdkRegion.
@region: a #GdkRegion.
Returns the smallest rectangle which includes the entire #GdkRegion.
@region: a #GdkRegion.
@rectangle: returns the smallest rectangle which includes all of @region.
Returns TRUE if the #GdkRegion is empty.
@region: a #GdkRegion.
@Returns: TRUE if @region is empty.
Returns TRUE if the two regions are the same.
@region1: a #GdkRegion.
@region2: a #GdkRegion.
@Returns: TRUE if @region1 and @region2 are equal.
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.
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.
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.
Moves a region the specified distance.
@region: a #GdkRegion.
@dx: the distance to move the region horizontally.
@dy: the distance to move the region vertically.
Resizes a region by the specified amount.
Positive values shrink the region. Negative values expand it.
@region: a #GdkRegion.
@dx: the number of pixels to shrink the region horizontally.
@dy: the number of pixels to shrink the region vertically.
Returns the union of a region and a rectangle.
@region: a #GdkRegion.
@rect: a #GdkRectangle.
@Returns: the union of @region and @rect.
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@source2:
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