gdkDrawRgbImage(object, gc, x, y, width, height, dith, rgb.buf, rowstride)
gdkDrawRgbImageDithalign(object, gc, x, y, width, height, dith, rgb.buf, xdith, ydith)
gdkDrawIndexedImage(object, gc, x, y, width, height, dith, buf, cmap)
gdkDrawGrayImage(object, gc, x, y, width, height, dith, buf)
gdkDrawRgb32Image(object, gc, x, y, width, height, dith, buf)
gdkDrawRgb32ImageDithalign(object, gc, x, y, width, height, dith, buf, xdith, ydith)
gdkRgbCmapNew(colors)
gdkRgbGcSetForeground(gc, rgb)
gdkRgbGcSetBackground(gc, rgb)
gdkRgbXpixelFromRgb(rgb)
gdkRgbFindColor(colormap, color)
gdkRgbSetInstall(install)
gdkRgbSetMinColors(min.colors)
gdkRgbGetVisual()
gdkRgbGetColormap()
gdkRgbDitherable()
gdkRgbColormapDitherable(colormap)
gdkRgbSetVerbose(verbose)GdkDrawable. It does this as efficiently as
possible, handling issues such as colormaps, visuals, dithering,
temporary buffers, and so on. Most code should use the higher-level
GdkPixbuf features in place of this module; for example,
gdkPixbufRenderToDrawable uses GdkRGB in its implementation.
GdkRGB allocates a color cube to use when rendering images. You can
set the threshold for installing colormaps with
gdkRgbSetMinColors. The default is 5x5x5 (125). If a colorcube
of this size or larger can be allocated in the default colormap, then
that's done. Otherwise, GdkRGB creates its own private colormap.
Setting it to 0 means that it always tries to use the default
colormap, and setting it to 216 means that it always creates a private
one if it cannot allocate the 6x6x6 colormap in the default. If you
always want a private colormap (to avoid consuming too many colormap
entries for other apps, say), you can use
gdk_rgb_set_install(TRUE).
Setting the value greater than 216 exercises a bug in older versions
of GdkRGB. Note, however, that setting it to 0 doesn't let you get
away with ignoring the colormap and visual - a colormap is always
created in grayscale and direct color modes, and the visual is changed
in cases where a "better" visual than the default is available.
# Simple example of using GdkRGB with RGtk2IMAGE_WIDTH <- 256 IMAGE_HEIGHT <- 256
rgb_example <- function() { window <- gtkWindow("toplevel", show = F) darea <- gtkDrawingArea() darea$setSizeRequest(IMAGE_WIDTH, IMAGE_HEIGHT) window$add(darea) # Set up the RGB buffer. x <- rep(0:(IMAGE_WIDTH-1), IMAGE_HEIGHT) y <- rep(0:(IMAGE_HEIGHT-1), IMAGE_WIDTH, each = T) red <- x - x green <- (x / 32) * 4 + y - y blue <- y - y buf <- rbind(red, green, blue) # connect to expose event gSignalConnect(darea, "expose-event", on_darea_expose, buf) window$showAll() }
on_darea_expose <- function(widget, event, buf) { gdkDrawRgbImage(widget[["window"]], widget[["style"]][["fgGc"]][[GtkStateType["normal"]+1]], 0, 0, IMAGE_WIDTH, IMAGE_HEIGHT, "max", buf, IMAGE_WIDTH * 3) }