rem: attr.render_mode = RM_DITHER;
add: attr.render_mode = RDitheredRendering;
context: int main(int argc, char **argv){    RContextAttributes attr;    dpy = XOpenDisplay("");    if (!dpy) {	puts("cant open display");	exit(1);    }    attr.flags = RC_RenderMode | RC_ColorsPerChannel;    attr.render_mode = RM_DITHER;    attr.colors_per_channel = 4;    ctx = RCreateContext(dpy, DefaultScreen(dpy), &attr);    if (argc<2) 	img = RGetImageFromXPMData(ctx, image_name);    else	img = RLoadImage(ctx, argv[1], 0);    if (!img) {	puts(RMessageForError(RErrorCode));	exit(1);    }    if (argc > 2) {	RImage *tmp = img;		img = RSmoothScaleImage(tmp, tmp->width*atol(argv[2]), 				tmp->height*atol(argv[2]));	RDestroyImage(tmp);    }    if (!RConvertImage(ctx, img, &pix)) {	puts(RMessageForError(RErrorCode));	exit(1);    }    win = XCreateSimpleWindow(dpy, DefaultRootWindow(dpy), 10, 10, img->width,			      img->height, 0, 0, 0);    RDestroyImage(img);    XSetWindowBackgroundPixmap(dpy, win, pix);    XClearWindow(dpy, win);    XMapRaised(dpy, win);    XFlush(dpy);    getchar();}