mirror of
https://gitlab.gnome.org/GNOME/gtk.git
synced 2024-11-07 01:00:28 +00:00
48298c1d98
2001-10-28 Anders Carlsson <andersca@gnu.org> * gdk/tmpl/regions.sgml: Remove note about coordinates in GdkPoint being 16-bit since they're 32-bit now. Fixes #62681.
324 lines
8.0 KiB
Plaintext
324 lines
8.0 KiB
Plaintext
<!-- ##### 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>
|
|
|
|
<!-- ##### 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>
|
|
Calculates the intersection of two rectangles.
|
|
</para>
|
|
|
|
@src1: a #GdkRectangle.
|
|
@src2: a #GdkRectangle.
|
|
@dest: the intersection of @src1 and @src2.
|
|
@Returns: TRUE if the rectangles intersect.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_rectangle_union ##### -->
|
|
<para>
|
|
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.
|
|
</para>
|
|
|
|
@src1: a #GdkRectangle.
|
|
@src2: a #GdkRectangle.
|
|
@dest: the union of @src1 and @src2.
|
|
|
|
|
|
<!-- ##### STRUCT GdkRegion ##### -->
|
|
<para>
|
|
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.
|
|
</para>
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_new ##### -->
|
|
<para>
|
|
Creates a new empty #GdkRegion.
|
|
</para>
|
|
|
|
@Returns: a new empty #GdkRegion.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_polygon ##### -->
|
|
<para>
|
|
Creates a new #GdkRegion using the polygon defined by a number of points.
|
|
|
|
</para>
|
|
|
|
@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.
|
|
|
|
|
|
<!-- ##### 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>
|
|
Destroys a #GdkRegion.
|
|
</para>
|
|
|
|
@region: a #GdkRegion.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_get_clipbox ##### -->
|
|
<para>
|
|
Returns the smallest rectangle which includes the entire #GdkRegion.
|
|
</para>
|
|
|
|
@region: a #GdkRegion.
|
|
@rectangle: returns the smallest rectangle which includes all of @region.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_get_rectangles ##### -->
|
|
<para>
|
|
|
|
</para>
|
|
|
|
@region:
|
|
@rectangles:
|
|
@n_rectangles:
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_empty ##### -->
|
|
<para>
|
|
Returns TRUE if the #GdkRegion is empty.
|
|
</para>
|
|
|
|
@region: a #GdkRegion.
|
|
@Returns: TRUE if @region is empty.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_equal ##### -->
|
|
<para>
|
|
Returns TRUE if the two regions are the same.
|
|
</para>
|
|
|
|
@region1: a #GdkRegion.
|
|
@region2: a #GdkRegion.
|
|
@Returns: TRUE if @region1 and @region2 are equal.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_point_in ##### -->
|
|
<para>
|
|
Returns TRUE if a point is in a region.
|
|
</para>
|
|
|
|
@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.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_rect_in ##### -->
|
|
<para>
|
|
Tests whether a rectangle is within a region.
|
|
</para>
|
|
|
|
@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 ##### -->
|
|
<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>
|
|
Moves a region the specified distance.
|
|
</para>
|
|
|
|
@region: a #GdkRegion.
|
|
@dx: the distance to move the region horizontally.
|
|
@dy: the distance to move the region vertically.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_shrink ##### -->
|
|
<para>
|
|
Resizes a region by the specified amount.
|
|
Positive values shrink the region. Negative values expand it.
|
|
</para>
|
|
|
|
@region: a #GdkRegion.
|
|
@dx: the number of pixels to shrink the region horizontally.
|
|
@dy: the number of pixels to shrink the region vertically.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_union_with_rect ##### -->
|
|
<para>
|
|
Sets the area of @region to the union of the areas of @region and
|
|
@rect. The resulting area is the set of pixels contained in
|
|
either @region or @rect.
|
|
|
|
</para>
|
|
|
|
@region: a #GdkRegion.
|
|
@rect: a #GdkRectangle.
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_intersect ##### -->
|
|
<para>
|
|
Sets the area of @source1 to the intersection of the areas of @source1
|
|
and @source2. The resulting area is the set of pixels contained in
|
|
both @source1 and @source2.
|
|
</para>
|
|
|
|
@source1: a #GdkRegion
|
|
@source2: a #GdkRegion
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_union ##### -->
|
|
<para>
|
|
Sets the area of @source1 to the union of the areas of @source1 and
|
|
@source2. The resulting area is the set of pixels contained in
|
|
either @source1 or @source2.
|
|
|
|
</para>
|
|
|
|
@source1: a #GdkRegion
|
|
@source2: a #GdkRegion
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_subtract ##### -->
|
|
<para>
|
|
Subtracts the area of @source2 from the area @source1. The resulting
|
|
area is the set of pixels contained in @source1 but not in @source2.
|
|
</para>
|
|
|
|
@source1: a #GdkRegion
|
|
@source2: a #GdkRegion
|
|
|
|
|
|
<!-- ##### FUNCTION gdk_region_xor ##### -->
|
|
<para>
|
|
Sets the area of @source1 to the exclusive-OR of the areas of @source1
|
|
and @source2. The resulting area is the set of pixels contained in one
|
|
or the other of the two sources but not in both.
|
|
</para>
|
|
|
|
@source1: a #GdkRegion
|
|
@source2: a #GdkRegion
|
|
|
|
|
|
<!-- ##### 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>
|
|
Calls a function on each span in the intersection of @region and
|
|
@spans.
|
|
</para>
|
|
|
|
@region: a #GdkRegion.
|
|
@spans: an array of #GdkSpans.
|
|
@n_spans: the length of @spans.
|
|
@sorted: %TRUE if @spans is sorted wrt. the y coordinate.
|
|
@function: function to call on each span in the intersection.
|
|
@data: data to pass to @function.
|
|
|
|
|