ref: cbe4b116989c0bfec49b9ae7a1d9a85ead6648ae
dir: /sys/src/cmd/bitsy/pencal.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
int debug = 0;
struct Cal {
double scalex;
double transx;
double scaley;
double transy;
} cal;
/* Calibrate the pen */
Point pts[5];
Point pens[5];
Point up = { 0, -10};
Point down = { 0, 10};
Point left = {-10, 0};
Point right = { 10, 0};
Point
pen2scr(Point p)
{
return Pt(p.x * cal.scalex / 65536.0 + cal.transx,
p.y * cal.scaley / 65536.0 + cal.transy);
}
Point
scr2pen(Point p)
{
return Pt((p.x - cal.transx) * 65536.0 / cal.scalex,
(p.y + cal.transy) * 65536.0 / cal.scaley);
}
void
cross(Point p) {
draw(screen, screen->r, display->white, nil, ZP);
line(screen, addpt(p, up), addpt(p, down), Endsquare, Endsquare, 0, display->black, ZP);
line(screen, addpt(p, left), addpt(p, right), Endsquare, Endsquare, 0, display->black, ZP);
flushimage(display, 1);
}
Point
getmouse(int mouse) {
static char buf[50];
int x, y, b, n;
Point p;
n = 0;
p.x = p.y = 0;
do{
if (read(mouse, buf, 48) != 48)
sysfatal("read: %r");
if (debug > 1) fprint(2, "%s\n", buf);
if (buf[0] == 'r') {
b = 1;
continue;
}
if (buf[0] != 'm')
sysfatal("mouse message: %s", buf);
x = strtol(buf+1, nil, 10);
y = strtol(buf+13, nil, 10);
b = strtol(buf+25, nil, 10);
p.x = (n * p.x + x)/(n+1);
p.y = (n * p.y + y)/(n+1);
n++;
}while (b & 0x7);
return p;
}
void
main(int argc, char **argv) {
int i, mouse, mousectl, wctl, ntries;
Rectangle r, oldsize;
ARGBEGIN{
case 'd':
debug = 1;
break;
}ARGEND;
if((mouse = open("/dev/mouse", OREAD)) < 0
&& (mouse = open("#m/mouse", OREAD)) < 0)
sysfatal("#m/mouse: %r");
mousectl = open("#m/mousectl", ORDWR);
if(mousectl < 0)
sysfatal("#m/mousectl: %r");
if(initdraw(nil, nil, "calibrate") < 0)
sysfatal("initdraw: %r");
wctl = -1;
for(ntries = 0; ntries < 3; ntries++){
r = insetrect(display->image->r, 2);
if(wctl < 0)
wctl = open("/dev/wctl", ORDWR);
if(wctl >= 0){
char buf[4*12+1];
buf[48] = 0;
oldsize = screen->r;
if(fprint(wctl, "resize -r %R", r) <= 0)
sysfatal("write /dev/wctl, %r");
if(getwindow(display, Refbackup) < 0)
sysfatal("getwindow");
if(debug) fprint(2, "resize: %R\n", screen->r);
if(read(mousectl, buf, 48) != 48)
sysfatal("read mousectl: %r");
if(debug > 1) fprint(2, "mousectl %s\n", buf);
if(buf[0] != 'c')
sysfatal("mousectl message: %s", buf);
cal.scalex = strtol(buf+ 1, nil, 10);
cal.scaley = strtol(buf+13, nil, 10);
cal.transx = strtol(buf+25, nil, 10);
cal.transy = strtol(buf+37, nil, 10);
}else{
fprint(mousectl, "calibrate");
cal.scalex = 1<<16;
cal.scaley = 1<<16;
cal.transx = 0;
cal.transy = 0;
}
fprint(2, "calibrate %ld %ld %ld %ld (old)\n",
(long)cal.scalex, (long)cal.scaley, (long)cal.transx, (long)cal.transy);
if(debug)
fprint(2, "screen coords %R\n", screen->r);
pts[0] = addpt(Pt( 16, 16), screen->r.min);
pts[1] = addpt(Pt( 16, -16), Pt(screen->r.min.x, screen->r.max.y));
pts[2] = addpt(Pt(-16, 16), Pt(screen->r.max.x, screen->r.min.y));
pts[3] = addpt(Pt(-16, -16), screen->r.max);
pts[4] = Pt((screen->r.max.x + screen->r.min.x)/2,
(screen->r.max.y + screen->r.min.y)/2);;
for(i = 0; i < 4; i++){
cross(pts[i]);
pens[i] = scr2pen(getmouse(mouse));
if (debug) fprint(2, "%P\n", pens[i]);
}
cal.scalex = (pts[2].x + pts[3].x - pts[0].x - pts[1].x) * 65536.0 /
(pens[2].x + pens[3].x - pens[0].x - pens[1].x);
cal.scaley = (pts[1].y + pts[3].y - pts[0].y - pts[2].y) * 65536.0 /
(pens[1].y + pens[3].y - pens[0].y - pens[2].y);
cal.transx = pts[0].x - (pens[0].x*cal.scalex) / 65536.0;
cal.transy = pts[0].y - (pens[0].y*cal.scaley) / 65536.0;
if(debug)
fprint(2, "scale [%f, %f], trans [%f, %f]\n",
cal.scalex, cal.scaley, cal.transx, cal.transy);
fprint(mousectl, "calibrate %ld %ld %ld %ld",
(long)cal.scalex, (long)cal.scaley, (long)cal.transx, (long)cal.transy);
cross(pts[4]);
pens[4] = getmouse(mouse);
draw(screen, screen->r, display->white, nil, ZP);
flushimage(display, 1);
if(abs(pts[4].x-pens[4].x) <= 4 && abs(pts[4].y-pens[4].y) <= 4){
fprint(2, "Calibration ok: %P -> %P\n", pts[4], pens[4]);
break;
}
fprint(2, "Calibration inaccurate: %P -> %P\n", pts[4], pens[4]);
}
print("calibrate='%ld %ld %ld %ld'\n",
(long)cal.scalex, (long)cal.scaley, (long)cal.transx, (long)cal.transy);
if(debug)
for(i = 0; i < 4; i++){
cross(pts[i]);
pens[i] = getmouse(mouse);
if (debug) fprint(2, "%P\n", pens[i]);
}
if(wctl >= 0)
fprint(wctl, "resize -r %R", oldsize);
}