/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <draw.h> Image*allocimagemix(Display *d, ulong color1, ulong color3){	Image *t, *b;	static Image *qmask; 	if(qmask == nil)		qmask = allocimage(d, Rect(0,0,1,1), GREY8, 1, 0x3F3F3FFF);			if(d->screenimage->depth <= 8){	/* create a 2×2 texture */		t = allocimage(d, Rect(0,0,1,1), d->screenimage->chan, 0, color1);		if(t == nil)			return nil; 		b = allocimage(d, Rect(0,0,2,2), d->screenimage->chan, 1, color3);		if(b == nil){			freeimage(t);			return nil;		} 		draw(b, Rect(0,0,1,1), t, nil, ZP);		freeimage(t);		return b;	}else{	/* use a solid color, blended using alpha */		t = allocimage(d, Rect(0,0,1,1), d->screenimage->chan, 1, color1);		if(t == nil)			return nil; 		b = allocimage(d, Rect(0,0,1,1), d->screenimage->chan, 1, color3);		if(b == nil){			freeimage(t);			return nil;		} 		draw(b, b->r, t, qmask, ZP);		freeimage(t);		return b;	}}