gdkDrawRgbImageDithalign: gdkDrawRgbImageDithalign
In RGtk2: R Bindings for Gtk 2.8.0 and Above

Description Usage Arguments Details Author(s)

Draws an RGB image in the drawable, with an adjustment for dither alignment.

1 2	gdkDrawRgbImageDithalign(object, gc, x, y, width, height, dith, rgb.buf, xdith, ydith)

`object`	The `GdkDrawable` to draw in (usually a `GdkWindow`).
`gc`	The graphics context.
`x`	The x coordinate of the top-left corner in the drawable.
`y`	The y coordinate of the top-left corner in the drawable.
`width`	The width of the rectangle to be drawn.
`height`	The height of the rectangle to be drawn.
`dith`	A `GdkRgbDither` value, selecting the desired dither mode.
`rgb.buf`	The pixel data, represented as packed 24-bit data.
`xdith`	An x offset for dither alignment.
`ydith`	A y offset for dither alignment.

This function is useful when drawing dithered images into a window that may be scrolled. Pixel (x, y) will be drawn dithered as if its actual location is (x + xdith, y + ydith). Thus, if you draw an image into a window using zero dither alignment, then scroll up one pixel, subsequent draws to the window should have ydith = 1.

Setting the dither alignment correctly allows updating of small parts of the screen while avoiding visible "seams" between the different dither textures.

Derived by RGtkGen from GTK+ documentation

RGtk2 documentation built on Oct. 14, 2021, 5:08 p.m.