tweak.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

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <cursor.h>
#include <event.h>
#include <bio.h>

typedef struct	Thing	Thing;

struct Thing
{
	Image	*b;
	Subfont 	*s;
	char		*name;	/* file name */
	int		face;		/* is 48x48 face file or cursor file*/
	Rectangle r;		/* drawing region */
	Rectangle tr;		/* text region */
	Rectangle er;		/* entire region */
	long		c;		/* character number in subfont */
	int		mod;	/* modified */
	int		mag;		/* magnification */
	Rune		off;		/* offset for subfont indices */
	Thing	*parent;	/* thing of which i'm an edit */
	Thing	*next;
};

enum
{
	Border	= 1,
	Up		= 1,
	Down	= 0,
	Mag		= 4,
	Maxmag	= 10,
};

enum
{
	NORMAL	=0,
	FACE	=1,
	CURSOR	=2
};

enum
{
	Mopen,
	Mread,
	Mwrite,
	Mcopy,
	Mchar,
	Mpixels,
	Mclose,
	Mexit,
};

enum
{
	Blue	= 54,
};

char	*menu3str[] = {
	[Mopen]	"open",
	[Mread]	"read",
	[Mwrite]	"write",
	[Mcopy]	"copy",
	[Mchar]	"char",
	[Mpixels]	"pixels",
	[Mclose]	"close",
	[Mexit]	"exit",
	0,
};

Menu	menu3 = {
	menu3str
};

Cursor sweep0 = {
	{-7, -7},
	{0x03, 0xC0, 0x03, 0xC0, 0x03, 0xC0, 0x03, 0xC0,
	 0x03, 0xC0, 0x03, 0xC0, 0xFF, 0xFF, 0xFF, 0xFF,
	 0xFF, 0xFF, 0xFF, 0xFF, 0x03, 0xC0, 0x03, 0xC0,
	 0x03, 0xC0, 0x03, 0xC0, 0x03, 0xC0, 0x03, 0xC0},
	{0x00, 0x00, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80,
	 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x7F, 0xFE,
	 0x7F, 0xFE, 0x01, 0x80, 0x01, 0x80, 0x01, 0x80,
	 0x01, 0x80, 0x01, 0x80, 0x01, 0x80, 0x00, 0x00}
};

Cursor box = {
	{-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 sight = {
	{-7, -7},
	{0x1F, 0xF8, 0x3F, 0xFC, 0x7F, 0xFE, 0xFB, 0xDF,
	 0xF3, 0xCF, 0xE3, 0xC7, 0xFF, 0xFF, 0xFF, 0xFF,
	 0xFF, 0xFF, 0xFF, 0xFF, 0xE3, 0xC7, 0xF3, 0xCF,
	 0x7B, 0xDF, 0x7F, 0xFE, 0x3F, 0xFC, 0x1F, 0xF8,},
	{0x00, 0x00, 0x0F, 0xF0, 0x31, 0x8C, 0x21, 0x84,
	 0x41, 0x82, 0x41, 0x82, 0x41, 0x82, 0x7F, 0xFE,
	 0x7F, 0xFE, 0x41, 0x82, 0x41, 0x82, 0x41, 0x82,
	 0x21, 0x84, 0x31, 0x8C, 0x0F, 0xF0, 0x00, 0x00,}
};

Cursor pixel = {
	{-7, -7},
	{0x1f, 0xf8, 0x3f, 0xfc,  0x7f, 0xfe,  0xf8, 0x1f,
	0xf0, 0x0f,  0xe0, 0x07, 0xe0, 0x07, 0xfe, 0x7f, 
	0xfe, 0x7f, 0xe0, 0x07, 0xe0, 0x07, 0xf0, 0x0f, 
	0x78, 0x1f, 0x7f, 0xfe, 0x3f, 0xfc, 0x1f, 0xf8, },
	{0x00, 0x00, 0x0f, 0xf0, 0x31, 0x8c, 0x21, 0x84, 
	0x41, 0x82, 0x41, 0x82, 0x41, 0x82, 0x40, 0x02, 
	0x40, 0x02, 0x41, 0x82, 0x41, 0x82, 0x41, 0x82, 
	0x21, 0x84, 0x31, 0x8c, 0x0f, 0xf0, 0x00, 0x00, }
};

Cursor busy = {
	{-7, -7},
	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
	 0x00, 0x00, 0x00, 0x0c, 0x00, 0x8e, 0x1d, 0xc7,
	 0xff, 0xe3, 0xff, 0xf3, 0xff, 0xff, 0x7f, 0xfe, 
	 0x3f, 0xf8, 0x17, 0xf0, 0x03, 0xe0, 0x00, 0x00,},
	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
	 0x00, 0x00, 0x00, 0x08, 0x00, 0x04, 0x00, 0x82,
	 0x04, 0x41, 0xff, 0xe1, 0x5f, 0xf1, 0x3f, 0xfe, 
	 0x17, 0xf0, 0x03, 0xe0, 0x00, 0x00, 0x00, 0x00,}
};

Cursor skull = {
	{-7,-7},
	{0x00, 0x00, 0x00, 0x00, 0xc0, 0x03, 0xe7, 0xe7, 
	 0xff, 0xff, 0xff, 0xff, 0x3f, 0xfc, 0x1f, 0xf8, 
	 0x0f, 0xf0, 0x3f, 0xfc, 0xff, 0xff, 0xff, 0xff, 
	 0xef, 0xf7, 0xc7, 0xe3, 0x00, 0x00, 0x00, 0x00,},
	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC0, 0x03,
	 0xE7, 0xE7, 0x3F, 0xFC, 0x0F, 0xF0, 0x0D, 0xB0,
	 0x07, 0xE0, 0x06, 0x60, 0x37, 0xEC, 0xE4, 0x27,
	 0xC3, 0xC3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,}
};

Rectangle	cntlr;		/* control region */
Rectangle	editr;		/* editing region */
Rectangle	textr;		/* text region */
Thing		*thing;
Mouse		mouse;
char		hex[] = "0123456789abcdefABCDEF";
jmp_buf		err;
char		*file;
int		mag;
int		but1val = 0;
int		but2val = 255;
int		invert = 0;
Image		*values[256];
Image		*greyvalues[256];
uchar		data[8192];

Thing*	tget(char*);
void	mesg(char*, ...);
void	drawthing(Thing*, int);
void	select(void);
void	menu(void);
void	error(Display*, char*);
void	buttons(int);
void	drawall(void);
void	tclose1(Thing*);

void
main(int argc, char *argv[])
{
	int i;
	Event e;
	Thing *t;

	mag = Mag;
	if(initdraw(error, 0, "tweak") < 0){
		fprint(2, "tweak: initdraw failed: %r\n");
		exits("initdraw");
	}
	for(i=0; i<256; i++){
		values[i] = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, cmap2rgba(i));
		greyvalues[i] = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, (i<<24)|(i<<16)|(i<<8)|0xFF);
		if(values[i] == 0 || greyvalues[i] == 0)
			drawerror(display, "can't allocate image");
	}
	einit(Emouse|Ekeyboard);
	eresized(0);
	i = 1;
	setjmp(err);
	for(; i<argc; i++){
		file = argv[i];
		t = tget(argv[i]);
		if(t)
			drawthing(t, 1);
		flushimage(display, 1);
	}
	file = 0;
	setjmp(err);
	for(;;)
		switch(event(&e)){
		case Ekeyboard:
			break;
		case Emouse:
			mouse = e.mouse;
			if(mouse.buttons & 3){
				select();
				break;
			}
			if(mouse.buttons & 4)
				menu();
		}
}

void
error(Display*, char *s)
{
	if(file)
		mesg("can't read %s: %s: %r", file, s);
	else
		mesg("/dev/bitblt error: %s", s);
	if(err[0])
		longjmp(err, 1);
	exits(s);
}

void
redraw(Thing *t)
{
	Thing *nt;
	Point p;

	if(thing==0 || thing==t)
		draw(screen, editr, display->white, nil, ZP);
	if(thing == 0)
		return;
	if(thing != t){
		for(nt=thing; nt->next!=t; nt=nt->next)
			;
		draw(screen, Rect(screen->r.min.x, nt->er.max.y, editr.max.x, editr.max.y),
			display->white, nil, ZP);
	}
	for(nt=t; nt; nt=nt->next){
		drawthing(nt, 0);
		if(nt->next == 0){
			p = Pt(editr.min.x, nt->er.max.y);
			draw(screen, Rpt(p, editr.max), display->white, nil, ZP);
		}
	}
	mesg("");
}

void
eresized(int new)
{
	if(new && getwindow(display, Refnone) < 0)
		error(display, "can't reattach to window");
	cntlr = insetrect(screen->clipr, 1);
	editr = cntlr;
	textr = editr;
	textr.min.y = textr.max.y - font->height;
	cntlr.max.y = cntlr.min.y + font->height;
	editr.min.y = cntlr.max.y+1;
	editr.max.y = textr.min.y-1;
	draw(screen, screen->clipr, display->white, nil, ZP);
	draw(screen, Rect(editr.min.x, editr.max.y, editr.max.x+1, editr.max.y+1), display->black, nil, ZP);
	replclipr(screen, 0, editr);
	drawall();
}

void
mesgstr(Point p, int line, char *s)
{
	Rectangle c, r;

	r.min = p;
	r.min.y += line*font->height;
	r.max.y = r.min.y+font->height;
	r.max.x = editr.max.x;
	c = screen->clipr;
	replclipr(screen, 0, r);
	draw(screen, r, values[0xDD], nil, ZP);
	r.min.x++;
	string(screen, r.min, display->black, ZP, font, s);
	replclipr(screen, 0, c);
	flushimage(display, 1);
}

void
mesg(char *fmt, ...)
{
	char buf[1024];
	va_list arg;

	va_start(arg, fmt);
	vseprint(buf, buf+sizeof(buf), fmt, arg);
	va_end(arg);
	mesgstr(textr.min, 0, buf);
}

void
tmesg(Thing *t, int line, char *fmt, ...)
{
	char buf[1024];
	va_list arg;

	va_start(arg, fmt);
	vseprint(buf, buf+sizeof(buf), fmt, arg);
	va_end(arg);
	mesgstr(t->tr.min, line, buf);
}


void
scntl(char *l)
{
	sprint(l, "mag: %d  but1: %d  but2: %d  invert-on-copy: %c", mag, but1val, but2val, "ny"[invert]);
}

void
cntl(void)
{
	char buf[256];

	scntl(buf);
	mesgstr(cntlr.min, 0, buf);
}

void
stext(Thing *t, char *l0, char *l1)
{
	Fontchar *fc;
	char buf[256];

	l1[0] = 0;
	sprint(buf, "depth:%d r:%d %d  %d %d ", 
		t->b->depth, t->b->r.min.x, t->b->r.min.y,
		t->b->r.max.x, t->b->r.max.y);
	if(t->parent)
		sprint(buf+strlen(buf), "mag: %d ", t->mag);
	sprint(l0, "%s file: %s", buf, t->name);
	if(t->c >= 0){
		fc = &t->parent->s->info[t->c];
		sprint(l1, "c(hex): %x c(char): %C x: %d "
			   "top: %d bottom: %d left: %d width: %d iwidth: %d",
			(int)(t->c+t->parent->off), (int)(t->c+t->parent->off),
			fc->x, fc->top, fc->bottom, fc->left,
			fc->width, Dx(t->b->r));
	}else if(t->s)
		sprint(l1, "offset(hex): %ux n:%d  height:%d  ascent:%d",
			t->off, t->s->n, t->s->height, t->s->ascent);
}

void
text(Thing *t)
{
	char l0[256], l1[256];

	stext(t, l0, l1);
	tmesg(t, 0, l0);
	if(l1[0])
		tmesg(t, 1, l1);
}

void
drawall(void)
{
	Thing *t;

	cntl();
	for(t=thing; t; t=t->next)
		drawthing(t, 0);
}

int
value(Image *b, int x)
{
	int v, l, w;
	uchar mask;

	w = b->depth;
	if(w > 8){
		mesg("ldepth too large");
		return 0;
	}
	l = log2[w];
	mask = (1<<w)-1;		/* ones at right end of word */
	x -= b->r.min.x&~(7>>l);	/* adjust x relative to first pixel */
	v = data[x>>(3-l)];
	v >>= ((7>>l)<<l) - ((x&(7>>l))<<l);	/* pixel at right end of word */
	v &= mask;			/* pixel at right end of word */
	return v;
}

int
bvalue(int v, int d)
{
	v &= (1<<d)-1;
	if(d > screen->depth)
		v >>= d - screen->depth;
	else
		while(d < screen->depth && d < 8){
			v |= v << d;
			d <<= 1;
		}
	if(v<0 || v>255){
		mesg("internal error: bad color");
		return Blue;
	}
	return v;
}

void
drawthing(Thing *nt, int link)
{
	int nl, nf, i, x, y, sx, sy, fdx, dx, dy, v;
	Thing *t;
	Subfont *s;
	Image *b, *col;
	Point p, p1, p2;

	if(link){
		nt->next = 0;
		if(thing == 0){
			thing = nt;
			y = editr.min.y;
		}else{
			for(t=thing; t->next; t=t->next)
				;
			t->next = nt;
			y = t->er.max.y;
		}
	}else{
		if(thing == nt)
			y = editr.min.y;
		else{
			for(t=thing; t->next!=nt; t=t->next)
				;
			y = t->er.max.y;
		}
	}
	s = nt->s;
	b = nt->b;
	nl = font->height;
	if(s || nt->c>=0)
		nl += font->height;
	fdx = Dx(editr) - 2*Border;
	dx = Dx(b->r);
	dy = Dy(b->r);
	if(nt->mag > 1){
		dx *= nt->mag;
		dy *= nt->mag;
		fdx -= fdx%nt->mag;
	}
	nf = 1 + dx/fdx;
	nt->er.min.y = y;
	nt->er.min.x = editr.min.x;
	nt->er.max.x = nt->er.min.x + Border + dx + Border;
	if(nt->er.max.x > editr.max.x)
		nt->er.max.x = editr.max.x;
	nt->er.max.y = nt->er.min.y + Border + nf*(dy+Border);
	nt->r = insetrect(nt->er, Border);
	nt->er.max.x = editr.max.x;
	draw(screen, nt->er, display->white, nil, ZP);
	for(i=0; i<nf; i++){
		p1 = Pt(nt->r.min.x-1, nt->r.min.y+i*(Border+dy));
		/* draw portion of bitmap */
		p = Pt(p1.x+1, p1.y);
		if(nt->mag == 1)
			draw(screen, Rect(p.x, p.y, p.x+fdx+Dx(b->r), p.y+Dy(b->r)),
				b, nil, Pt(b->r.min.x+i*fdx, b->r.min.y));
		else{
			for(y=b->r.min.y; y<b->r.max.y; y++){
				sy = p.y+(y-b->r.min.y)*nt->mag;
				unloadimage(b, Rect(b->r.min.x, y, b->r.max.x, y+1), data, sizeof data);
				for(x=b->r.min.x+i*(fdx/nt->mag); x<b->r.max.x; x++){
					sx = p.x+(x-i*(fdx/nt->mag)-b->r.min.x)*nt->mag;
					if(sx >= nt->r.max.x)
						break;
					v = bvalue(value(b, x), b->depth);
					if(v == 255)
						continue;
					if(b->chan == GREY8)
						draw(screen, Rect(sx, sy, sx+nt->mag, sy+nt->mag),
							greyvalues[v], nil, ZP);
					else
						draw(screen, Rect(sx, sy, sx+nt->mag, sy+nt->mag),
							values[v], nil, ZP);
				}

			}
		}
		/* line down left */
		if(i == 0)
			col = display->black;
		else
			col = display->white;
		draw(screen, Rect(p1.x, p1.y, p1.x+1, p1.y+dy+Border), col, nil, ZP);
		/* line across top */
		draw(screen, Rect(p1.x, p1.y-1, nt->r.max.x+Border, p1.y), display->black, nil, ZP);
		p2 = p1;
		if(i == nf-1){
			p2.x += 1 + dx%fdx;
			col = display->black;
		}else{
			p2.x = nt->r.max.x;
			col = display->white;
		}
		/* line down right */
		draw(screen, Rect(p2.x, p2.y, p2.x+1, p2.y+dy+Border), col, nil, ZP);
		/* line across bottom */
		if(i == nf-1){
			p1.y += Border+dy;
			draw(screen, Rect(p1.x, p1.y-1, p2.x,p1.y), display->black, nil, ZP);
		}
	}
	nt->tr.min.x = editr.min.x;
	nt->tr.max.x = editr.max.x;
	nt->tr.min.y = nt->er.max.y + Border;
	nt->tr.max.y = nt->tr.min.y + nl;
	nt->er.max.y = nt->tr.max.y + Border;
	text(nt);
}

int
tohex(int c)
{
	if('0'<=c && c<='9')
		return c - '0';
	if('a'<=c && c<='f')
		return 10 + (c - 'a');
	if('A'<=c && c<='F')
		return 10 + (c - 'A');
	return 0;
}

Thing*
tget(char *file)
{
	int i, j, fd, face, x, y, c, chan;
	Image *b;
	Subfont *s;
	Thing *t;
	Dir *d;
	jmp_buf oerr;
	uchar buf[256];
	char *data;

	buf[0] = '\0';
	errstr((char*)buf, sizeof buf);	/* flush pending error message */
	memmove(oerr, err, sizeof err);
	d = nil;
	if(setjmp(err)){
   Err:
		free(d);
		memmove(err, oerr, sizeof err);
		return 0;
	}
	fd = open(file, OREAD);
	if(fd < 0){
		mesg("can't open %s: %r", file);
		goto Err;
	}
	d = dirfstat(fd);
	if(d == nil){
		mesg("can't stat bitmap file %s: %r", file);
		close(fd);
		goto Err;
	}
	if(read(fd, buf, 11) != 11){
		mesg("can't read %s: %r", file);
		close(fd);
		goto Err;
	}
	seek(fd, 0, 0);
	data = (char*)buf;
	if(*data == '{')
		data++;
	if(memcmp(data, "0x", 2)==0 && data[4]==','){
		/*
		 * cursor file
		 */
		face = CURSOR;
		s = 0;
		data = malloc(d->length+1);
		if(data == 0){
			mesg("can't malloc buffer: %r");
			close(fd);
			goto Err;
		}
		data[d->length] = 0;
		if(read(fd, data, d->length) != d->length){
			mesg("can't read cursor file %s: %r", file);
			close(fd);
			goto Err;
		}
		b = allocimage(display, Rect(0, 0, 16, 32), GREY1, 0, DNofill);
		if(b == 0){
			mesg("image alloc failed file %s: %r", file);
			free(data);
			close(fd);
			goto Err;
		}
		i = 0;
		for(x=0;x<64; ){
			if((c=data[i]) == '\0')
				goto ill;
			if(c=='0' && data[i+1] == 'x'){
				i += 2;
				continue;
			}
			if(strchr(hex, c)){
				buf[x++] = (tohex(c)<<4) | tohex(data[i+1]);
				i += 2;
				continue;
			}
			i++;
		}
		loadimage(b, Rect(0, 0, 16, 32), buf, sizeof buf);
		free(data);
	}else if(memcmp(buf, "0x", 2)==0){
		/*
		 * face file
		 */
		face = FACE;
		s = 0;
		data = malloc(d->length+1);
		if(data == 0){
			mesg("can't malloc buffer: %r");
			close(fd);
			goto Err;
		}
		data[d->length] = 0;
		if(read(fd, data, d->length) != d->length){
			mesg("can't read bitmap file %s: %r", file);
			close(fd);
			goto Err;
		}
		for(y=0,i=0; i<d->length; i++)
			if(data[i] == '\n')
				y++;
		if(y == 0){
	ill:
			mesg("ill-formed face file %s", file);
			close(fd);
			free(data);
			goto Err;
		}
		for(x=0,i=0; (c=data[i])!='\n'; ){
			if(c==',' || c==' ' || c=='\t'){
				i++;
				continue;
			}
			if(c=='0' && data[i+1] == 'x'){
				i += 2;
				continue;
			}
			if(strchr(hex, c)){
				x += 4;
				i++;
				continue;
			}
			goto ill;
		}
		if(x % y)
			goto ill;
		switch(x / y){
		default:
			goto ill;
		case 1:
			chan = GREY1;
			break;
		case 2:
			chan = GREY2;
			break;
		case 4: