regions.sgml

This GTK+ version 2.12.3. GTK+ is a multi-platform toolkit for creating graphical user interfaces.

<!-- ##### SECTION Title ##### -->
Points, Rectangles and Regions

<!-- ##### SECTION Short_Description ##### -->
Simple graphical data types

<!-- ##### SECTION Long_Description ##### -->
<para>
GDK provides the #GdkPoint, #GdkRectangle, #GdkRegion and #GdkSpan data types
for representing pixels and sets of pixels on the screen.
</para>
<para>
#GdkPoint is a simple structure containing an x and y coordinate of a point.
</para>
<para>
#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().
</para>
<para>
#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()).
</para>
<para>
#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().
</para>

<!-- ##### SECTION See_Also ##### -->
<para>

</para>

<!-- ##### SECTION Stability_Level ##### -->


<!-- ##### STRUCT GdkPoint ##### -->
<para>
Defines the x and y coordinates of a point.
</para>

@x: the x coordinate of the point.
@y: the y coordinate of the point.

<!-- ##### STRUCT GdkRectangle ##### -->
<para>
Defines the position and size of a rectangle.
</para>

@x: the x coordinate of the left edge of the rectangle.
@y: the y coordinate of the top of the rectangle.
@width: the width of the rectangle.
@height: the height of the rectangle.

<!-- ##### FUNCTION gdk_rectangle_intersect ##### -->
<para>

</para>

@src1: 
@src2: 
@dest: 
@Returns: 


<!-- ##### FUNCTION gdk_rectangle_union ##### -->
<para>

</para>

@src1: 
@src2: 
@dest: 


<!-- ##### STRUCT GdkRegion ##### -->
<para>
A GdkRegion represents a set of pixels on the screen.
</para>


<!-- ##### FUNCTION gdk_region_new ##### -->
<para>

</para>

@Returns: 


<!-- ##### FUNCTION gdk_region_polygon ##### -->
<para>

</para>

@points: 
@npoints: 
@fill_rule: 
@Returns: 


<!-- ##### ENUM GdkFillRule ##### -->
<para>
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.
</para>

@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.

<!-- ##### FUNCTION gdk_region_copy ##### -->
<para>

</para>

@region: 
@Returns: 


<!-- ##### FUNCTION gdk_region_rectangle ##### -->
<para>

</para>

@rectangle: 
@Returns: 


<!-- ##### FUNCTION gdk_region_destroy ##### -->
<para>

</para>

@region: 


<!-- ##### FUNCTION gdk_region_get_clipbox ##### -->
<para>

</para>

@region: 
@rectangle: 


<!-- ##### FUNCTION gdk_region_get_rectangles ##### -->
<para>

</para>

@region: 
@rectangles: 
@n_rectangles: 


<!-- ##### FUNCTION gdk_region_empty ##### -->
<para>

</para>

@region: 
@Returns: 


<!-- ##### FUNCTION gdk_region_equal ##### -->
<para>

</para>

@region1: 
@region2: 
@Returns: 


<!-- ##### FUNCTION gdk_region_point_in ##### -->
<para>

</para>

@region: 
@x: 
@y: 
@Returns: 


<!-- ##### FUNCTION gdk_region_rect_in ##### -->
<para>

</para>

@region: 
@rectangle: 
@Returns: 


<!-- ##### ENUM GdkOverlapType ##### -->
<para>
Specifies the possible values returned by gdk_region_rect_in().
</para>

@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.

<!-- ##### FUNCTION gdk_region_offset ##### -->
<para>

</para>

@region: 
@dx: 
@dy: 


<!-- ##### FUNCTION gdk_region_shrink ##### -->
<para>

</para>

@region: 
@dx: 
@dy: 


<!-- ##### FUNCTION gdk_region_union_with_rect ##### -->
<para>

</para>

@region: 
@rect: 


<!-- ##### FUNCTION gdk_region_intersect ##### -->
<para>
</para>

@source1: 
@source2: 


<!-- ##### FUNCTION gdk_region_union ##### -->
<para>

</para>

@source1: 
@source2: 


<!-- ##### FUNCTION gdk_region_subtract ##### -->
<para>
</para>

@source1: 
@source2: 


<!-- ##### FUNCTION gdk_region_xor ##### -->
<para>
</para>

@source1: 
@source2: 


<!-- ##### STRUCT GdkSpan ##### -->
<para>
A GdkSpan represents a horizontal line of pixels starting
at the pixel with coordinates @x, @y and ending before @x + @width, @y.
</para>

@x: x coordinate of the first pixel.
@y: y coordinate of the first pixel.
@width: number of pixels in the span.

<!-- ##### USER_FUNCTION GdkSpanFunc ##### -->
<para>
This defines the type of the function passed to 
gdk_region_spans_intersect_foreach(). 
</para>

@span: a #GdkSpan.
@data: the user data passed to gdk_region_spans_intersect_foreach().


<!-- ##### FUNCTION gdk_region_spans_intersect_foreach ##### -->
<para>

</para>

@region: 
@spans: 
@n_spans: 
@sorted: 
@function: 
@data: