gdk-Points-Rectangles-and-Regions {RGtk2} | R Documentation

## Points, Rectangles and Regions

### Description

Simple graphical data types

### Methods and Functions

`gdkRectangleIntersect(src1, src2)`
`gdkRectangleUnion(src1, src2)`
`gdkRegionNew()`
`gdkRegionPolygon(points, fill.rule)`
`gdkRegionCopy(object)`
`gdkRegionRectangle(rectangle)`
`gdkRegionGetClipbox(object)`
`gdkRegionGetRectangles(object)`
`gdkRegionEmpty(object)`
`gdkRegionEqual(object, region2)`
`gdkRegionRectEqual(object, rectangle)`
`gdkRegionPointIn(object, x, y)`
`gdkRegionRectIn(object, rect)`
`gdkRegionOffset(object, dx, dy)`
`gdkRegionShrink(object, dx, dy)`
`gdkRegionUnionWithRect(object, rect)`
`gdkRegionIntersect(object, source2)`
`gdkRegionUnion(object, source2)`
`gdkRegionSubtract(object, source2)`
`gdkRegionXor(object, source2)`
`gdkRegionSpansIntersectForeach(object, spans, sorted, fun, data)`

### Detailed Description

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 `gdkRectangleIntersect`. To find the union of two rectangles use `gdkRectangleUnion`. `GdkRegion` is an opaque data type holding a set of arbitrary pixels, and is usually used for clipping graphical operations (see `gdkGCSetClipRegion`). `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 `gdkRegionSpansIntersectForeach`.

### Structures

`GdkPoint`

  Defines the x and y coordinates of a point. `GdkPoint` is a transparent-type.

  `x`

    the x coordinate of the point.

  `y`

    the y coordinate of the point.

`GdkRectangle`

  Defines the position and size of a rectangle. `GdkRectangle` is a transparent-type.

  `x`

    [integer] the x coordinate of the left edge of the rectangle.

  `y`

    [integer] the y coordinate of the top of the rectangle.

  `width`

    [integer] the width of the rectangle.

  `height`

    [integer] the height of the rectangle.

`GdkRegion`

  A GdkRegion represents a set of pixels on the screen.

`GdkSpan`

  A GdkSpan represents a horizontal line of pixels starting at the pixel with coordinates `x`, `y` and ending before `x` + `width`, `y`. `GdkSpan` is a transparent-type.

  `x`

    [integer] x coordinate of the first pixel.

  `y`

    [integer] y coordinate of the first pixel.

  `width`

    [integer] number of pixels in the span.

### Enums and Flags

`GdkFillRule`

  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.

  `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.

  `winding-rule`

    overlapping areas are always included.

`GdkOverlapType`

  Specifies the possible values returned by `gdkRegionRectIn`.

  `in`

    if the rectangle is inside the `GdkRegion`.

  `out`

    if the rectangle is outside the `GdkRegion`.

  `part`

    if the rectangle is partly inside the `GdkRegion`.

### User Functions

`GdkSpanFunc(span, data)`

  This defines the type of the function passed to `gdkRegionSpansIntersectForeach`.

  `span`

    a `GdkSpan`.

  `data`

    the user data passed to `gdkRegionSpansIntersectForeach`.

### Author(s)

Derived by RGtkGen from GTK+ documentation

### References

https://developer.gnome.org/gdk2/stable/gdk2-Points-Rectangles-and-Regions.html

[Package RGtk2 version 2.20.36.3 Index]