mug.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

		i = d.y;
		if(i < 0){
			/*
			 * should really check i/2, but this is safe and feedback
			 * makes the control feel right
			 */
			i = -min(-i, a[Right]);
			i = max(i, a[Left]);
		}
		i = max(i, a[Top]);
		if(i >= Dy(r))
			break;
		r.min.y += i;
		/* divide the half bit equally */
		toggle = 1-toggle;
		if(toggle){
			r.min.x += i/2;
			r.max.x = r.min.x+Dy(r);
		}else{
			r.max.x -= i/2;
			r.min.x = r.max.x-Dy(r);
		}
		break;
	case RTopRight:
		i = (-d.x+d.y)/2;
		if(i>=Dx(r) || i>=Dy(r))
			break;
		i = -min(-i, a[Right]);
		i = max(i, a[Top]);
		r.max.x -= i;
		r.min.y += i;
		break;
	case RLeft:
		i = d.x;
		if(i < 0){
			i = -min(-i, a[Bottom]);
			i = max(i, a[Top]);
		}
		i = max(i, a[Left]);
		if(i >= Dx(r))
			break;
		r.min.x += i;
		/* divide the half bit equally */
		toggle = 1-toggle;
		if(toggle){
			r.min.y += i/2;
			r.max.y = r.min.y+Dx(r);
		}else{
			r.max.y -= i/2;
			r.min.y = r.max.y-Dx(r);
		}
		break;
	case RMiddle:
		if(d.x >= 0)
			d.x = min(d.x, a[Right]);
		else
			d.x = max(d.x, a[Left]);
		if(d.y >= 0)
			d.y = min(d.y, a[Bottom]);
		else
			d.y = max(d.y, a[Top]);
		r = rectaddpt(r, d);
		break;
	case RRight:
		i = d.x;
		if(i > 0){
			i = min(i, a[Bottom]);
			i = -max(-i, a[Top]);
		}
		i = min(i, a[Right]);
		if(-i >= Dx(r))
			break;
		r.max.x += i;
		/* divide the half bit equally */
		toggle = 1-toggle;
		if(toggle){
			r.min.y -= i/2;
			r.max.y = r.min.y+Dx(r);
		}else{
			r.max.y += i/2;
			r.min.y = r.max.y-Dx(r);
		}
		break;
	case RBotLeft:
		i = (d.x+-d.y)/2;
		if(i>=Dx(r) || i>=Dy(r))
			break;
		i = max(i, a[Left]);
		i = -min(-i, a[Bottom]);
		r.min.x += i;
		r.max.y -= i;
		break;
	case RBot:
		i = d.y;
		if(i > 0){
			i = min(i, a[Right]);
			i = -max(-i, a[Left]);
		}
		i = min(i, a[Bottom]);
		if(i >= Dy(r))
			break;
		r.max.y += i;
		/* divide the half bit equally */
		toggle = 1-toggle;
		if(toggle){
			r.min.x -= i/2;
			r.max.x = r.min.x+Dy(r);
		}else{
			r.max.x += i/2;
			r.min.x = r.max.x-Dy(r);
		}
		break;
	case RBotRight:
		i = (-d.x+-d.y)/2;
		if(i>=Dx(r) || i>=Dy(r))
			break;
		i = -min(-i, a[Right]);
		i = -min(-i, a[Bottom]);
		r.max.x -= i;
		r.max.y -= i;
		break;
	}
	if(Dx(r)<3 || Dy(r)<3){
		*rp = oldr;
		return 0;
	}
	*rp = r;
	return !eqrect(r, oldr);
}

void
rlist(Rectangle r, Rectangle *ra)
{
	Rectangle tr;

	tr = r;
	tr.max.y = r.min.y+Dy(r)/4;
	ra[0] = tr;
	ra[0].max.x = tr.min.x+Dx(tr)/4;
	ra[1] = tr;
	ra[1].min.x = ra[0].max.x;
	ra[1].max.x = tr.max.x-Dx(tr)/4;
	ra[2] = tr;
	ra[2].min.x = ra[1].max.x;

	tr.min.y = tr.max.y;
	tr.max.y = r.max.y-Dy(r)/4;
	ra[3] = tr;
	ra[3].max.x = tr.min.x+Dx(tr)/4;
	ra[4] = tr;
	ra[4].min.x = ra[3].max.x;
	ra[4].max.x = tr.max.x-Dx(tr)/4;
	ra[5] = tr;
	ra[5].min.x = ra[4].max.x;

	tr.min.y = tr.max.y;
	tr.max.y = r.max.y;
	ra[6] = tr;
	ra[6].max.x = tr.min.x+Dx(tr)/4;
	ra[7] = tr;
	ra[7].min.x = ra[6].max.x;
	ra[7].max.x = tr.max.x-Dx(tr)/4;
	ra[8] = tr;
	ra[8].min.x = ra[7].max.x;
}

int
abs(int a)
{
	if(a < 0)
		return -a;
	return a;
}

void
usage(void)
{
	fprint(2, "usage: mug [file.bit]\n");
	exits("usage");
}

void
eresized(int new)
{
	if(new && getwindow(display, Refmesg) < 0)
		fprint(2,"can't reattach to window");
	drawscreen(1);

}

/*
interface notes

cursor changes while in rbig to indicate region.
only button 1 works for resizing region
only button 1 works for moving thingy in ramp

button-3 menu: Reset, Depth, Undo, Save, Write
*/

Cursor tl = {
	{-4, -4},
	{0xfe, 0x00, 0x82, 0x00, 0x8c, 0x00, 0x87, 0xff, 
	 0xa0, 0x01, 0xb0, 0x01, 0xd0, 0x01, 0x11, 0xff, 
	 0x11, 0x00, 0x11, 0x00, 0x11, 0x00, 0x11, 0x00, 
	 0x11, 0x00, 0x11, 0x00, 0x11, 0x00, 0x1f, 0x00, },
	{0x00, 0x00, 0x7c, 0x00, 0x70, 0x00, 0x78, 0x00, 
	 0x5f, 0xfe, 0x4f, 0xfe, 0x0f, 0xfe, 0x0e, 0x00, 
	 0x0e, 0x00, 0x0e, 0x00, 0x0e, 0x00, 0x0e, 0x00, 
	 0x0e, 0x00, 0x0e, 0x00, 0x0e, 0x00, 0x00, 0x00, }
};

Cursor t = {
	{-7, -8},
	{0x00, 0x00, 0x00, 0x00, 0x03, 0x80, 0x06, 0xc0, 
	 0x1c, 0x70, 0x10, 0x10, 0x0c, 0x60, 0xfc, 0x7f, 
	 0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 0xff, 0xff, 
	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, },
	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 
	 0x03, 0x80, 0x0f, 0xe0, 0x03, 0x80, 0x03, 0x80, 
	 0x7f, 0xfe, 0x7f, 0xfe, 0x7f, 0xfe, 0x00, 0x00, 
	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }
};

Cursor tr = {
	{-11, -4},
	{0x00, 0x7f, 0x00, 0x41, 0x00, 0x31, 0xff, 0xe1, 
	 0x80, 0x05, 0x80, 0x0d, 0x80, 0x0b, 0xff, 0x88, 
	 0x00, 0x88, 0x0, 0x88, 0x00, 0x88, 0x00, 0x88, 
	 0x00, 0x88, 0x00, 0x88, 0x00, 0x88, 0x00, 0xf8, },
	{0x00, 0x00, 0x00, 0x3e, 0x00, 0x0e, 0x00, 0x1e, 
	 0x7f, 0xfa, 0x7f, 0xf2, 0x7f, 0xf0, 0x00, 0x70, 
	 0x00, 0x70, 0x00, 0x70, 0x00, 0x70, 0x00, 0x70, 
	 0x00, 0x70, 0x00, 0x70, 0x00, 0x70, 0x00, 0x00, }
};

Cursor r = {
	{-8, -7},
	{0x07, 0xc0, 0x04, 0x40, 0x04, 0x40, 0x04, 0x58, 
	 0x04, 0x68, 0x04, 0x6c, 0x04, 0x06, 0x04, 0x02, 
	 0x04, 0x06, 0x04, 0x6c, 0x04, 0x68, 0x04, 0x58, 
	 0x04, 0x40, 0x04, 0x40, 0x04, 0x40, 0x07, 0xc0, },
	{0x00, 0x00, 0x03, 0x80, 0x03, 0x80, 0x03, 0x80, 
	 0x03, 0x90, 0x03, 0x90, 0x03, 0xf8, 0x03, 0xfc, 
	 0x03, 0xf8, 0x03, 0x90, 0x03, 0x90, 0x03, 0x80, 
	 0x03, 0x80, 0x03, 0x80, 0x03, 0x80, 0x00, 0x00, }
};

Cursor br = {
	{-11, -11},
	{0x00, 0xf8, 0x00, 0x88, 0x00, 0x88, 0x00, 0x88, 
	 0x00, 0x88, 0x00, 0x88, 0x00, 0x88, 0x00, 0x88, 
	 0xff, 0x88, 0x80, 0x0b, 0x80, 0x0d, 0x80, 0x05, 
	 0xff, 0xe1, 0x00, 0x31, 0x00, 0x41, 0x00, 0x7f, },
	{0x00, 0x00, 0x00, 0x70, 0x00, 0x70, 0x00, 0x70, 
	 0x0, 0x70, 0x00, 0x70, 0x00, 0x70, 0x00, 0x70, 
	 0x00, 0x70, 0x7f, 0xf0, 0x7f, 0xf2, 0x7f, 0xfa, 
	 0x00, 0x1e, 0x00, 0x0e, 0x00, 0x3e, 0x00, 0x00, }
};

Cursor b = {
	{-7, -7},
	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
	 0xff, 0xff, 0x80, 0x01, 0x80, 0x01, 0x80, 0x01, 
	 0xfc, 0x7f, 0x0c, 0x60, 0x10, 0x10, 0x1c, 0x70, 
	 0x06, 0xc0, 0x03, 0x80, 0x00, 0x00, 0x00, 0x00, },
	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
	 0x00, 0x00, 0x7f, 0xfe, 0x7f, 0xfe, 0x7f, 0xfe, 
	 0x03, 0x80, 0x03, 0x80, 0x0f, 0xe0, 0x03, 0x80, 
	 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }
};

Cursor bl = {
	{-4, -11},
	{0x1f, 0x00, 0x11, 0x00, 0x11, 0x00, 0x11, 0x00, 
	 0x11, 0x00, 0x11, 0x00, 0x11, 0x00, 0x11, 0x00, 
	 0x11, 0xff, 0xd0, 0x01, 0xb0, 0x01, 0xa0, 0x01, 
	 0x87, 0xff, 0x8c, 0x00, 0x82, 0x00, 0xfe, 0x00, },
	{0x00, 0x00, 0x0e, 0x00, 0x0e, 0x00, 0x0e, 0x00, 
	 0x0e, 0x00, 0x0e, 0x00, 0x0e, 0x00, 0x0e, 0x00, 
	 0x0e, 0x00, 0x0f, 0xfe, 0x4f, 0xfe, 0x5f, 0xfe, 
	 0x78, 0x00, 0x70, 0x00, 0x7c, 0x00, 0x00, 0x0, }
};

Cursor l = {
	{-7, -7},
	{0x03, 0xe0, 0x02, 0x20, 0x02, 0x20, 0x1a, 0x20, 
	 0x16, 0x20, 0x36, 0x20, 0x60, 0x20, 0x40, 0x20, 
	 0x60, 0x20, 0x36, 0x20, 0x16, 0x20, 0x1a, 0x20, 
	 0x02, 0x20, 0x02, 0x20, 0x02, 0x20, 0x03, 0xe0, },
	{0x00, 0x00, 0x01, 0xc0, 0x01, 0xc0, 0x01, 0xc0, 
	 0x09, 0xc0, 0x09, 0xc0, 0x1f, 0xc0, 0x3f, 0xc0, 
	 0x1f, 0xc0, 0x09, 0xc0, 0x09, 0xc0, 0x01, 0xc0, 
	 0x01, 0xc0, 0x01, 0xc0, 0x01, 0xc0, 0x00, 0x00, }
};

Cursor boxcursor = {
	{-7, -7},
	{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
	 0xFF, 0xFF, 0xF8, 0x1F, 0xF8, 0x1F, 0xF8, 0x1F,
	 0xF8, 0x1F, 0xF8, 0x1F, 0xF8, 0x1F, 0xFF, 0xFF,
	 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, },
	{0x00, 0x00, 0x7F, 0xFE, 0x7F, 0xFE, 0x7F, 0xFE,
	 0x70, 0x0E, 0x70, 0x0E, 0x70, 0x0E, 0x70, 0x0E,
	 0x70, 0x0E, 0x70, 0x0E, 0x70, 0x0E, 0x70, 0x0E,
	 0x7F, 0xFE, 0x7F, 0xFE, 0x7F, 0xFE, 0x00, 0x00, }
};

Cursor clearcursor;

Cursor *corners[10] = {
	&tl,	&t,	&tr,
	&l,	&boxcursor,	&r,
	&bl,	&b,	&br,
	nil,	/* default arrow */
};

char *item[] = {
	"Reset",
	"Depth",
	"Undo",
	"Write",
	"Exit",
	nil
};

Menu menu = {
	item, 
	nil,
	2
};

/*BUG make less flashy */
void
moveface(Image *back, Point lastp, Image *face, Point p, Point d)
{
	draw(screen, rectaddpt(back->r, subpt(lastp, d)), back, nil, back->r.min);
	draw(back, back->r, screen, nil, addpt(back->r.min, subpt(p, d)));
	border(screen, rectaddpt(face->r, subpt(p, d)),
		 -1, display->black, ZP);
	draw(screen, rectaddpt(face->r, subpt(p, d)), 
		face, nil, face->r.min);
}

int
dragface(Mouse *m, Image *im, Point d, int x)
{
	int i;
	Point lastp;
	static Image *back;

	if(back == nil){
		back = allocimage(display, Rect(-1,-1,49,49), display->image->chan, 0, DNofill);
		if(back == nil)
			sysfatal("dragface backing store: %r");
	}

	lastp = m->xy;
	draw(back, back->r, screen, nil, addpt(back->r.min, subpt(lastp, d)));
	esetcursor(&clearcursor);
	do{
		moveface(back, lastp, im, m->xy, d);
		lastp = m->xy;
	}while(*m=emouse(), m->buttons==1);

	draw(screen, rectaddpt(back->r, subpt(lastp, d)), back, nil, back->r.min);
	esetcursor(nil);
	if(m->buttons==0){
		for(i=0; i<nelem(face); i++)
			if(ptinrect(m->xy, rface[i]))
				return i;
		if(ptinrect(m->xy, rsmall))
			return -1;
		return x;
	}
	while(*m=emouse(), m->buttons)
		;
	return x;
}

void
initstate(void)
{
	state.black = 0.0;
	state.white = 1.0;
	state.stretch = 1.0;
	state.depth = 4;
	state.gamma = 1.0;
	setgtab(&state);
	state.selr = insetrect(orig->r, 5);
	sdx = Dx(state.selr);
	sdy = Dy(state.selr);
	if(sdx > sdy)
		state.selr.max.x = state.selr.min.x+sdy;
	else
		state.selr.max.y = state.selr.min.y+sdx;
}

void
main(int argc, char **argv)
{
	int ccursor, i, fd, k, n, y;
	uchar *data;
	double gammatab[256];
	Event e;
	Mouse m;
	Point lastp, p;
	Rectangle nselr, rbig9[9];

	ARGBEGIN{
	default:
		usage();
	}ARGEND

	if(argc > 1)
		usage();
	if(argc == 1){
		if((fd = open(argv[0], OREAD)) < 0)
			sysfatal("open %s: %r", argv[0]);
	}else
		fd = 0;

	initdraw(0, 0, "mug");

	if((orig = readimage(display, fd, 0)) == nil)
		sysfatal("readimage: %r");

	orig = grey8image(orig);

	initramp();
	initclamp();
	initval2cmap();
	bkgd = allocimagemix(display, DPaleyellow, DWhite);
	small = allocimage(display, Rect(0,0,48,48), GREY4, 0, DWhite);
	tmp8 = allocimage(display, Rect(0,0,48,48), GREY8, 0, DWhite);
	red = allocimage(display, Rect(0,0,1,1), display->image->chan, 1, DRed);
	green = allocimage(display, Rect(0,0,1,1), display->image->chan, 1, DGreen);
	blue = allocimage(display, Rect(0,0,1,1), display->image->chan, 1, DBlue);
	if(bkgd==nil || small==nil || tmp8==nil || red==nil || green==nil || blue==nil)
		sysfatal("allocimage: %r");

	n = Dx(orig->r)*Dy(orig->r);
	data = emalloc(n*sizeof data[0]);
	rdata = emalloc(n*sizeof rdata[0]);

	if(unloadimage(orig, orig->r, data, n) != n)
		sysfatal("unloadimage: %r");
	
	for(i=0; i<256; i++)
		gammatab[i] = pow((255-i)/(double)255.0, GAMMA);

	for(i=0; i<n; i++)
		rdata[i] = gammatab[255-data[i]];

	initstate();
	process(rdata, orig->r, state.selr, small);
	drawscreen(1);
	flushimage(display, 1);
	einit(Emouse|Ekeyboard);
	ccursor = 9;
	for(;;){
		if((n=eread(Emouse|Ekeyboard, &e))==Ekeyboard)
			continue;
		if(n != Emouse)
			break;

		m = e.mouse;
		if(m.buttons&4){
			ccursor = 9;
			esetcursor(corners[ccursor]);
			switch(emenuhit(3, &m, &menu)){
			case -1:
				continue;
			case 0:	/* Reset */
				mark();
				initstate();
				small = allocimage(display, Rect(0,0,48,48), CHAN1(CGrey, state.depth), 0, DWhite);
				if(small == nil)
					sysfatal("allocimage: %r");
				process(rdata, orig->r, state.selr, small);
				drawface(-1);
				drawscreen(0);
				break;
			case 1:	/* Depth */
				mark();
				/* osmall = small, so no freeimage */
				state.depth /= 2;
				if(state.depth == 0)
					state.depth = 8;
				small = allocimage(display, Rect(0,0,48,48), CHAN1(CGrey, state.depth), 0, DWhite);
				if(small == nil)
					sysfatal("allocimage: %r");
				process(rdata, orig->r, state.selr, small);
				drawface(-1);
				break;
			case 2:	/* Undo */
				undo();
				break;
			case 3:	/* Write */
				writeface(nil, small);
				break;
			case 4:	/* Exit */
				exits(nil);
				break;
			}
		}
			
		if(ptinrect(m.xy, rbig)){
			rlist(rectaddpt(state.selr, subpt(rbig.min, orig->r.min)), rbig9);
			for(i=0; i<9; i++)
				if(ptinrect(m.xy, rbig9[i]))
					break;
			if(i != ccursor){
				ccursor = i;
				esetcursor(corners[ccursor]);
			}
			if(i==9)
				continue;

			if(m.buttons & 1){
				mark();
				lastp = m.xy;
				while(m=emouse(), m.buttons&1){
					if(move(state.selr, orig->r, subpt(m.xy, lastp), i, &nselr)){
						moveframe(state.selr, nselr);
						state.selr = nselr;
						lastp = m.xy;
						process(rdata, orig->r, state.selr, small);
						drawface(-1);
					}
				}
			}
			continue;
		}

		if(ccursor != 9){	/* default cursor */
			ccursor = 9;
			esetcursor(corners[ccursor]);
		}

		if(ptinrect(m.xy, rramp)){
			if(m.buttons != 1)
				continue;
			mark();
			y = gamma2y(state.gamma);
			if(abs(y-(m.xy.y-rramp.min.y)) > 5)
				continue;
			k = section(m.xy.x-rramp.min.x);
			drawrampbar(green, &state);
			lastp = m.xy;
			while(m=emouse(), m.buttons&1){
				if(!ptinrect(m.xy, rramp))
					continue;
				switch(k){
				case -1:
					continue;
				case 0:
					if((m.xy.x-rramp.min.x)/255.0 < state.white){
						state.black = (m.xy.x-rramp.min.x)/255.0;
						break;
					}
					continue;
				case 1:
					state.gamma = y2gamma(m.xy.y-rramp.min.y);
					setgtab(&state);
					break;
				case 2:
					if((m.xy.x-rramp.min.x)/255.0 > state.black){
						state.white = (m.xy.x-rramp.min.x)/255.0;
						break;
					}
					continue;
				case 10:
					state.black += (m.xy.x-lastp.x)/255.0;
					state.white += (m.xy.x-lastp.x)/255.0;
					state.gamma = y2gamma(p.y);
					break;
				}
				process(rdata, orig->r, state.selr, small);
				drawface(-1);
				drawrampbar(green, &state);
			}
			if(m.buttons == 0){
				process(rdata, orig->r, state.selr, small);
				drawface(-1);
				drawrampbar(red, &state);
			}else
				undo();
			continue;
		}
	
		if(ptinrect(m.xy, rsmall)){
			if(m.buttons != 1)
				continue;
			n=dragface(&m, small, subpt(m.xy, rsmall.min), -1);
			if(n == -1)
				continue;
			saveface(nil, n);
		}
	
		for(i=0; i<nelem(face); i++)
			if(ptinrect(m.xy, rface[i]))
				break;
		if(i<nelem(face) && face[i] != nil){
			if(m.buttons != 1)
				continue;
			n=dragface(&m, face[i]->small, subpt(m.xy, rface[i].min), i);
			if(n == i)
				continue;
			saveface(face[i], n);
			continue;
		}

		do
			m = emouse();
		while(m.buttons==1);
	}
	exits(nil);
}