implement Touchcal; ## calibrate a touch screen## Copyright © 2001 Vita Nuova Holdings Limited.  All rights reserved.# include "sys.m";	sys:	Sys; include "draw.m";	draw:	Draw;	Display, Font, Image, Point, Pointer, Rect: import draw; include "tk.m"; include "wmclient.m";	wmclient: Wmclient;	Window: import wmclient; include "translate.m";	translate: Translate;	Dict: import translate; Touchcal: module{	init:	fn(ctxt: ref Draw->Context, argv: list of string);};  Margin: con 20; prompt:= "Please tap the centre\nof the cross\nwith the stylus"; mousepid := 0; init(ctxt: ref Draw->Context, args: list of string){	r: Rect;	disp: ref Image; 	if(args != nil)		args = tl args;	debug := args != nil && hd args == "-d";	sys = load Sys Sys->PATH;	draw = load Draw Draw->PATH;	if(draw == nil)		err(sys->sprint("no Draw module: %r"));	sys->pctl(Sys->NEWPGRP|Sys->FORKFD, nil);	translate = load Translate Translate->PATH;	if(translate != nil){		translate->init();		(dict, nil) := translate->opendict(translate->mkdictname("", "touchcal"));		if(dict != nil)			prompt = dict.xlate(prompt);		dict = nil;		translate = nil;	} 	display: ref Display;	win: ref Window;	ptr: chan of ref Pointer;	if(ctxt != nil){		display = ctxt.display;		wmclient = load Wmclient Wmclient->PATH;		if(wmclient == nil)			err(sys->sprint("cannot load %s: %r", Wmclient->PATH));		wmclient->init();		win = wmclient->window(ctxt, "Touchcal", Wmclient->Plain);		win.reshape(ctxt.display.image.r);		ptr = chan of ref Pointer;		win.onscreen("exact");		win.startinput("ptr"::nil);		pidc := chan of int;		ptr = win.ctxt.ptr;		display = ctxt.display;		disp = win.image;		r = disp.r;	}else{		# standalone, catch them ourselves		display = draw->Display.allocate(nil);		disp = display.image;		r = disp.r;		mfd := sys->open("/dev/pointer", Sys->OREAD);		if(mfd == nil)			err(sys->sprint("can't open /dev/pointer: %r"));		pidc := chan of int;		ptr = chan of ref Pointer;		spawn rawmouse(mfd, ptr, pidc);		mousepid = <-pidc;	}	white := display.white;	black := display.black;	red := display.color(Draw->Red);	disp.draw(r, white, nil, r.min);	samples := array[4] of Point;	points := array[4] of Point;	points[0] = (r.min.x+Margin, r.min.y+Margin);	points[1] = (r.max.x-Margin, r.min.y+Margin);	points[2] = (r.max.x-Margin, r.max.y-Margin);	points[3] = (r.min.x+Margin, r.max.y-Margin);	midpoint := Point((r.min.x+r.max.x)/2, (r.min.y+r.max.y)/2);	refx := FX((points[1].x - points[0].x) + (points[2].x - points[3].x), 1);	refy := FX((points[3].y - points[0].y) + (points[2].y - points[1].y), 1);	ctl := sys->open("/dev/touchctl", Sys->ORDWR);	if(ctl == nil)		ctl = sys->open("/dev/null", Sys->ORDWR);	if(ctl == nil)		err(sys->sprint("can't open /dev/touchctl: %r"));	#oldvalues := array[128] of byte;	#nr := sys->read(ctl, oldvalues, len oldvalues);	#if(nr < 0)	#	err(sys->sprint("can't read old values from /dev/touchctl: %r"));	#oldvalues = oldvalues[0:nr];	sys->fprint(ctl, "X %d %d %d\nY %d %d %d\n", FX(1,1), 0, 0, 0, FX(1,1), 0);	# identity	font := Font.open(display, sys->sprint("/fonts/lucida/unicode.%d.font", 6+(r.dx()/512)));	if(font == nil)		font = Font.open(display, "*default*");	if(font != nil){		drawtext(disp, midpoint, black, font, prompt);		font = nil;	}	for(;;) {		tm := array[] of {0 to 2 =>array[] of {0, 0, 0}};		for(i := 0; i < 4; i++){			cross(disp, points[i], red);			samples[i] = getpoint(ptr);			cross(disp, points[i], white);		}		# first, rotate if necessary		rotate := 0;		if(abs(samples[1].x-samples[2].x) > 80 && abs(samples[2].y-samples[3].y) > 80){			rotate = 1;			for(i = 0; i < len samples; i++)				samples[i] = (samples[i].y, samples[i].x);		}		# calculate scaling and offset transformations		actx := (samples[1].x-samples[0].x)+(samples[2].x-samples[3].x);		acty := (samples[3].y-samples[0].y)+(samples[2].y-samples[1].y);		if(actx == 0 || acty == 0)			continue;		# either the user or device is not trying		tm[0][rotate] = refx/actx;		tm[0][2] = FX(points[0].x - XF(tm[0][rotate]*samples[0].x), 1);		tm[1][1-rotate] = refy/acty;		tm[1][2] = FX(points[0].y - XF(tm[1][1-rotate]*samples[0].y), 1);		cross(disp, midpoint, red);		m := getpoint(ptr);		cross(disp, midpoint, white);		p := Point(ptmap(tm[0], m.x, m.y), ptmap(tm[1], m.x, m.y));		if(debug){			for(k:=0; k<4; k++)				sys->print("%d %d,%d %d,%d\n", k, points[k].x,points[k].y, samples[k].x, samples[k].y);			if(rotate)				sys->print("rotated\n");			sys->print("rx=%d ax=%d ry=%d ay=%d tm[0][0]=%d\n", refx, actx, refy, acty, tm[0][0]);			sys->print("%g %g %g\n%g %g %g\n",				G(tm[0][0]), G(tm[0][1]), G(tm[0][2]),				G(tm[1][0]), G(tm[1][1]), G(tm[1][2]));			sys->print("%d %d -> %d %d (%d %d)\n", m.x, m.y, p.x, p.y, midpoint.x, midpoint.y);		}		if(abs(p.x-midpoint.x) > 5 || abs(p.y-midpoint.y) > 5)			continue;		printmat(sys->fildes(1), tm);		if(debug || printmat(ctl, tm) >= 0){			disp.draw(r, white, nil, r.min);			break;		}		sys->fprint(sys->fildes(2), "touchcal: can't set calibration: %r\n");	}	if(mousepid > 0)		kill(mousepid);} printmat(fd: ref Sys->FD, tm: array of array of int): int{	return sys->fprint(fd, "X %d %d %d\nY %d %d %d\n",		    tm[0][0], tm[0][1], tm[0][2],		    tm[1][0], tm[1][1], tm[1][2]);} FX(a, b: int): int{	return (a << 16)/b;} XF(v: int): int{	return v>>16;} G(v: int): real{	return real v / 65536.0;} ptmap(m: array of int, x, y: int): int{	return XF(m[0]*x + m[1]*y + m[2]);} rawmouse(fd: ref Sys->FD, mc: chan of ref Pointer, pidc: chan of int){	pidc <-= sys->pctl(0, nil);	buf := array[64] of byte;	for(;;){		n := sys->read(fd, buf, len buf);		if(n <= 0)			err(sys->sprint("can't read /dev/pointer: %r")); 		if(int buf[0] != 'm' || n < 1+3*12)			continue; 		x := int string buf[ 1:13];		y := int string buf[12:25];		b := int string buf[24:37];		mc <-= ref Pointer(b, (x,y), 0);	}} getpoint(mousec: chan of ref Pointer): Point{	p := Point(0,0);	while((m := <-mousec).buttons == 0)		p = m.xy;	n := 0;	do{		if(abs(p.x-m.xy.x) > 10 || abs(p.y-m.xy.y) > 10){			n = 0;			p = m.xy;		}else{			p = p.mul(n).add(m.xy).div(n+1);			n++;		}	}while((m = <-mousec).buttons & 7);	return p;} cross(im: ref Image, p: Point, col: ref Image){	im.line(p.sub((0,10)), p.add((0,10)), Draw->Endsquare, Draw->Endsquare, 0, col, col.r.min);	im.line(p.sub((10,0)), p.add((10,0)), Draw->Endsquare, Draw->Endsquare, 0, col, col.r.min);	im.flush(Draw->Flushnow);} drawtext(im: ref Image, p: Point, col: ref Image, font: ref Font, text: string){	(n, lines) := sys->tokenize(text, "\n");	p = p.sub((0, (n+1)*font.height));	for(; lines != nil; lines = tl lines){		s := hd lines;		w := font.width(s);		im.text(p.sub((w/2, 0)), col, col.r.min, font, s);		p = p.add((0, font.height));	}} abs(x: int): int{	if(x < 0)		return -x;	return x;} kill(pid: int){	fd := sys->open("#p/"+string pid+"/ctl", Sys->OWRITE);	if(fd != nil)		sys->fprint(fd, "kill");} err(s: string){	sys->fprint(sys->fildes(2), "touchcal: %s\n", s);	if(mousepid > 0)		kill(mousepid);	raise "fail:touch";}