RGtk2 (version 2.12.17)

gdkDrawRgbImageDithalign: 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.