gdkDrawRgbImageDithalign {RGtk2}R Documentation

gdkDrawRgbImageDithalign

Description

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

Usage

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

Arguments

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

Details

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.

Author(s)

Derived by RGtkGen from GTK+ documentation


[Package RGtk2 version 2.12.5-3 Index]