#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <mouse.h>
#include <keyboard.h>
#include <cursor.h>
enum{NEXTROW, INSTR, NOTE, BEND, GLOBAL, LOOP, MARK};
typedef struct Event Event; struct Event{
	Event *next;
	int index; /* row << 8 | col << 3 | type */
	union{
		struct{uchar r20, r23, r40, r43, r60, r63, r80, r83, re0, re3, rc0;};
		struct{int freq; uchar ra0, rb0; char note[4];};
		int bend;
		struct{int bpm; uchar rpb, tpr, r104, rbd;};
		int loop;
		char *mark;
	};
}*song, **edit;
char *keys = "\t1q2we4r5t6yu8i9op-[=]\b\\", *notes = "CCDDEFFGGAAB";
int freq[18], bend[18], ed, eds, tickopl, tpr, horiz, wid, row, col, skipoff, skip = 1;
int looping, loopstart, loopend, snarfrow, snarfcol = -1;
vlong tickns;
uchar rb0[18], rc0[18], mute[18];
Image *bg[2], *hl, *fg;
Mousectl *⌖;
char *wave[] = {
	/* OPL2 */	"Sine", "Half Sine", "Absolute Sin", "Pulse Sine",
	/*OPL3 */	"Even Sine", "Even Abs Sin", "Square", "Derived Sq", nil
};
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
	}
}, audio = {
	{-7,-7}, {0}, {
		0x00, 0x80, 0x02, 0x04, 0x06, 0x022, 0x0e, 0xf12,
		0x1e, 0x91, 0xfe, 0x89, 0xfe, 0x49, 0xfe, 0x49,
		0xfe, 0x49, 0xfe, 0x49, 0xfe, 0x89, 0x1e, 0x91,
		0x0e, 0xf12, 0x06, 0x022, 0x02, 0x04, 0x00, 0x80
	}
};
int menulen;
char*
menugen(int n){
	static char buf[6];
	if(n < 0 || n >= menulen)
		return nil;
	sprint(buf, "%d", n);
	return buf;
}
int
menu(int v, char **s, int but){
	Menu m;
	m.item = s;
	m.gen = menugen;
	m.lasthit = v;
	menuhit(but, ⌖, &m, nil);
	return m.lasthit;
}
void
reged(uchar *r, int mask, int shift){
	menulen = mask + 1;
	*r = *r & ~(mask << shift) | menu(*r >> shift & mask, nil, 1) << shift;
}
void
hist(int n, int obliterate){
	Event **ep, *e;
	while(n){
		if(n > 0){ /* redo */
			if(ed == eds)
				return;
			e = edit[ed++];
			n--;
		}else{ /* undo */
			if(ed == 0)
				return;
			e = edit[--ed];
			n++;
		}
		ep = &song;
		while(*ep != nil && (*ep)->index < e->index)
			ep = &(*ep)->next;
		if(*ep != e){ /* insert / undelete */
			e->next = *ep;
			*ep = e;
		}else{ /* delete / uninsert */
			*ep = e->next;
			if(obliterate){
				if((e->index & 7) == MARK)
					free(e->mark);
				free(e);
			}
		}
	}
}
void
newedit(Event *e){
	static int max;
	int old;
	old = ed;
	hist(eds - ed, 0);
	hist(old - eds, 1);
	if(ed == max){
		max += 1024;
		edit = realloc(edit, max * sizeof e);
		if(edit == nil)
			sysfatal("realloc: %r");
		setrealloctag(edit, getcallerpc(&e));
	}
	edit[ed] = e;
	eds = ed + 1;
}
void
delete(Event *e){
	newedit(e);
	hist(1, 0);
}
void
insert(Event *new){
	Event *e;
	for(e = song; e != nil && e->index < new->index; e = e->next)
		;
	if(e != nil && e->index == new->index)
		delete(e);
	newedit(new);
	hist(1, 0);
}
Event*
newevent(int index){
	Event  *e;
	e = malloc(sizeof(Event));
	if(e == nil)
		sysfatal("malloc: %r");
	setmalloctag(e, getcallerpc(&index));
	e->index = index;
	return e;
}
void
evdup(Event *e, Event *f){
	switch(e->index & 7){
	case INSTR:
		e->r20 = f->r20;
		e->r23 = f->r23;
		e->r40 = f->r40;
		e->r43 = f->r43;
		e->r60 = f->r60;
		e->r63 = f->r63;
		e->r80 = f->r80;
		e->r83 = f->r83;
		e->re0 = f->re0;
		e->re3 = f->re3;
		e->rc0 = f->rc0;
		break;
	case NOTE:
		e->freq = f->freq;
		e->ra0 = f->ra0;
		e->rb0 = f->rb0;
		e->note[0] = f->note[0];
		e->note[1] = f->note[1];
		e->note[2] = f->note[2];
		e->note[3] = f->note[3];
		break;
	case BEND:
		e->bend = f->bend;
		break;
	case GLOBAL:
		e->bpm = f->bpm;
		e->rpb = f->rpb;
		e->tpr = f->tpr;
		e->r104 = f->r104;
		e->rbd = f->rbd;
		break;
	case LOOP:
		e->loop = f->loop;
		break;
	case MARK:
		e->mark = strdup(f->mark);
		break;
	}
}
int
fnum(int n){ /* fnum * 49716 = hz << 20 - block */
	int f;
	f = 440.0 / 49716.0 * pow(2.0, n / 384.0);
	for(n = 1; n < 7 && f > 1023; n++)
		f >>= 1;
	return n << 10 | f;
}
void
fmtnote(Event *e, int n){
	e->note[1] = e->note[2] = e->note[3] = 0;
	if(n == 0xff){
		e->note[0] = 'x';
		return;
	}
	e->note[0] = notes[n % 12];
	if(n && notes[(n - 1) % 12] == e->note[0]){
		e->note[1] = '#';
		e->note[2] = '0' + n / 12;
	}else
		e->note[1] = '0' + n / 12;
	/* internal frequency unit: 32ths of a semitone distant from A4, shifted up 19 octaves */
	e->freq = n - 57 + 19 * 12 << 5;
	n = fnum(e->freq);
	e->ra0 = n;
	e->rb0 = 0x20 | n >> 8;
}
void
resize(void){
	getwindow(display, Refnone);
	horiz = screen->r.min.y + Dy(screen->r) / font->height / 3 * font->height;
}
void
redraw(void){
	Event *e;
	int i;
	Point p;
	char buf[8];
	draw(screen, screen->r, bg[0], nil, ZP);
	p = Pt(screen->r.min.x + 2 * wid, screen->r.min.y);
	buf[1] = 0;
	for(buf[0] = 'A'; buf[0] <= 'R'; buf[0]++){
		if(mute[buf[0] - 'A'])
			draw(screen, Rect(p.x, p.y, p.x + wid, p.y + font->height), hl, nil, ZP);
		string(screen, p, fg, ZP, font, buf);
		p.x += wid;
	}
	buf[0] = 'X';
	string(screen, p, fg, ZP, font, buf);
	i = (horiz - screen->r.min.y) / font->height - 1;
	if(row < i)
		i = row;
	p = Pt(screen->r.min.x, horiz - i * font->height);
	i = row - i << 8;
	for(e = song; e != nil && e->index < i; e = e->next)
		;
	while(p.y < screen->r.max.y && i < 0x7fffff00){
		p.x = screen->r.min.x;
		draw(screen, Rect(p.x, p.y, screen->r.max.x, p.y + font->height),
			bg[(skipoff + (i >> 8)) % skip != 0], nil, ZP);
		sprint(buf, "%06ux", i >> 8);
		string(screen, p, fg, ZP, font, buf);
		i += 0x100;
		while(e != nil && e->index < i){
			p.x = screen->r.min.x + (2 + (e->index >> 3 & 31)) * wid;
			switch(e->index & 7){
			case INSTR:
				draw(screen, Rect(p.x, p.y, p.x + wid, p.y + font->height), hl, nil, ZP);
				break;
			case NOTE:
				string(screen, p, fg, ZP, font, e->note);
				break;
			case BEND:
				p.x += wid - stringwidth(font, "↓");
				string(screen, p, fg, ZP, font, e->bend < 0 ? "↓" : "↑");
				break;
			case GLOBAL:
				draw(screen, Rect(p.x, p.y, p.x + wid, p.y + font->height), hl, nil, ZP);
				break;
			case LOOP:
				if(e->loop == 1)
					strcpy(buf, "|: ");
				else
					sprint(buf, ":|%d ", e->loop);
				p = string(screen, p, fg, ZP, font, buf);
				if(e->next == nil || e->next->index != e->index + 1)
					break;
				e = e->next;
			case MARK:
				string(screen, p, fg, ZP, font, e->mark);
				break;
			}
			e = e->next;
		}
		p.y += font->height;
	}
	p = Pt(screen->r.min.x + (2 + col) * wid, screen->r.min.y);
	draw(screen, Rect(p.x - 2, p.y, p.x, screen->r.max.y), hl, nil, ZP);
	draw(screen, Rect(p.x + wid, p.y, p.x + wid + 2, screen->r.max.y), hl, nil, ZP);
	draw(screen, Rect(screen->r.min.x, horiz - 2, screen->r.max.x, horiz), hl, nil, ZP);
	draw(screen, Rect(screen->r.min.x, horiz + font->height, screen->r.max.x, horiz + font->height + 2), hl, nil, ZP);
	flushimage(display, 1);
}
char*
process(Event *e, char *b){
	char x;
	x = e->index >> 3 & 31;
	switch(e->index & 7){
	default:
		sysfatal("unrecognized event type");
	case INSTR:
		b[3] = b[4] = b[8] = b[9] = b[13] = b[14] = b[18] = b[19] = b[23] = b[24] = b[28] = b[29]
		= b[33] = b[34] = b[38] = b[39] = b[43] = b[44] = b[48] = b[49] = b[53] = b[54] = 0;
		b[1] = b[6] = b[11] = b[16] = b[21] = b[26] = b[31] = b[36] = b[41] = b[46] = b[51] = x & 1;
		b[50] = 0xc0 | x >> 1;
		rc0[x] = e->rc0;
		b[52] = e->rc0 & ~mute[x];
		x = x / 6 << 3 | x % 6 >> 1;
		b[0] = 0x20 | x; b[2] = e->r20; b[5] = b[0] + 3; b[7] = e->r23;
		b[10] = 0x40 | x; b[12] = e->r40; b[15] = b[10] + 3; b[17] =e->r43;
		b[20] = 0x60 | x; b[22] = e->r60; b[25] = b[20] + 3; b[27] = e->r63;
		b[30] = 0x80 | x; b[32] = e->r80; b[35] = b[30] + 3; b[37] = e->r83;
		b[40] = 0xe0 | x; b[42] = e->re0; b[45] = b[40] + 3; b[47] = e->re3;
		return b + 55;
	case NOTE:
		b[1] = b[6] = b[11] = x & 1;
		b[3] = b[4] = b[8] = b[9] = b[13] = b[14] = 0;
		b[5] = 0xa0 | x >> 1;
		b[0] = b[10] = b[5] | 0x10;
		b[2] = rb0[x] &= 0xdf;
		if(e->note[0] == 'x')
			return b + 5;
		b[7] = e->ra0;
		b[12] = rb0[x] = e->rb0;
		freq[x] = e->freq;	
		return b + 15;
	case BEND:
		bend[x] = e->bend;
		break;
	case GLOBAL:
		tpr = e->tpr;
		tickns = 60000000000LL / e->bpm / e->rpb / tpr;
		tickopl = 60 * 49716 / e->bpm / e->rpb / tpr;
		b[3] = b[4] = b[8] = b[9] = 0;
		b[0] = 0xbd;
		b[1] = 0;
		b[2] = e->rbd;
		b[5] = 0x04;
		b[6] = 1;
		b[7] = e->r104;
		return b + 10;
	case LOOP:
		if(looping == 0){
			loopstart = loopend + 1;
			loopend = e->index >> 8;
			looping = e->loop;
		}
		looping--;
	case MARK:
		break;
	}
	return b;
}
char*
bends(char *b){
	int i, f;
	for(i = 0; i < 18; i++)
		if(bend[i]){
			b[3] = b[4] = b[8] = b[9] = 0;
			b[1] = b[6] = i & 1;
			b[0] = 0xa0 | i >> 1;
			b[5] = b[0] | 0x10;
			f = fnum(freq[i] += bend[i]);
			b[2] = f;
			b[7] = rb0[i] = rb0[i] & 0x20 | f >> 8;
			b += 10;
		}
	return b;
}
int
startopl(void){
	int p[2], a;
	a = open("/dev/audio", OWRITE);
	if(a < 0)
		return -1;
	if(pipe(p) < 0){
		close(a);
		return -1;
	}
	switch(fork()){
	case -1:
		close(a);
		close(p[0]);
		close(p[1]);
		return -1;
	case 0:
		dup(p[1], 0);
		dup(a, 1);
		close(a);
		close(p[0]);
		close(p[1]);
		execl("/bin/games/opl3", "opl3", "-s", nil);
		sysfatal("execl: %r");
	}
	close(p[1]);
	close(a);
	write(p[0], "\1\0 \0\0\5\1\1\0", 10);
	setcursor(⌖, &audio);
	for(a = 0; a < 18; a++)
		freq[a] = rb0[a] = rc0[a] = 0;
	/* default: 120 bpm, 4 rpb, 4 tpr → tick = 31.25 ms */
	tpr = 4;
	tickns = 60000000000LL / 120 / 4 / tpr;
	tickopl = 60 * 49716 / 120 / 4 / tpr;
	return p[0];
}
void
threadmain(int argc, char **argv){
	Keyboardctl *⌨;
	Point p;
	Rune k;
	Event **ep, *e, *snarf = nil;
	vlong t;
	char buf[4092], *b, *path;
	int fd, i, j, oct = 48;
	char *b2s[] = {"voice", "note", "bend", nil};
	char *b2sx[] = {"global", "loop", "mark", nil};
	char *b3s[] = {"undo", "jump", " skip = 1 ", "select", "paste", "select", "write", "quit", nil};
	Menu b2m = {b2s, nil, 0}, b3m = {b3s, nil, 0};
	enum{RESIZE, MOUSE, KEYBOARD, NOTHING};
	Alt a[] = {
		[RESIZE]{nil, nil, CHANRCV},
		[MOUSE]{nil, nil, CHANRCV},
		[KEYBOARD]{nil, &k, CHANRCV},
		[NOTHING]{nil, nil, CHANEND}
	};
	if(argc > 2)
		sysfatal("usage: %s [file]", argv[0]);
	if(argc == 2){
		path = argv[1];
		fd = open(path, OREAD);
		if(fd < 0)
			sysfatal("open: %r");
		t = j = 0;
		ep = &song;
		while(9){
			b = buf + j;
			i = read(fd, b, sizeof buf - j);
			if(i <= 0)
				break;
			i += j;
			b = buf;
			while(b < buf + i){
				switch(*b & 7){
				default:
					sysfatal("bad file format: unrecognized event type 0x%02ux", *b & 0xff);
				case NEXTROW:
					t++;
					b++;
					continue;
				case INSTR:
					if(b + 12 > buf + i)
						break;
					*ep = e = newevent(t << 8 | b[0] & 0xff);
					ep = &e->next;
					e->r20 = b[1]; e->r23 = b[2];
					e->r40 = b[3]; e->r43 = b[4];
					e->r60 = b[5]; e->r63 = b[6];
					e->r80 = b[7]; e->r83 = b[8];
					e->re0 = b[9]; e->re3 = b[10];
					e->rc0 = b[11];
					b += 12;
					continue;
				case NOTE:
					if(b + 2 > buf + i)
						break;
					*ep = e = newevent(t << 8 | b[0] & 0xff);
					ep = &e->next;
					fmtnote(e, b[1] & 0xff);
					b += 2;
					continue;
				case BEND:
					if(b + 2 > buf + i)
						break;
					*ep = e = newevent(t << 8 | b[0] & 0xff);
					ep = &e->next;
					e->bend = (schar)b[1];
					b += 2;
					continue;
				case GLOBAL:
					if(b + 5 > buf + i)
						break;
					*ep = e = newevent(t << 8 | b[0] & 0xff);
					ep = &e->next;
					e->bpm = (b[1] & 0xff) + 30;
					e->rpb = (b[2] & 7) + 1;
					e->tpr = (b[2] >> 4 & 7) + 1;
					e->r104 = b[3];
					e->rbd = b[4];
					b += 5;
					continue;
				case LOOP:
					if(b + 2 > buf + i)
						break;
					*ep = e = newevent(t << 8 | b[0] & 0xff);
					ep = &e->next;
					e->loop = b[1] & 0xff;
					b += 2;
					continue;
				case MARK:
					if(memchr(b, 0, buf - b + i) == nil){
						if(b == buf)
							sysfatal("mark string too long for buffer!");
						break;
					}
					*ep = e = newevent(t << 8 | b[0] & 0xff);
					ep = &e->next;
					e->mark = strdup(b + 1);
					b = strchr(b, 0);
					continue;
				}
				break;
			}
			j = buf + i - b;
			memmove(buf, b, j);
		}
		*ep = nil;
		close(fd);
		if(i < 0)
			sysfatal("read: %r");
		if(i)
			sysfatal("bad file format: short read");
	}else
		path = nil;
	sprint(buf, "%s %s", argv[0], path);
	if(initdraw(nil, nil, buf) < 0)
		sysfatal("initdraw: %r");
	wid = stringwidth(font, "000");
	bg[0] = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, DPalegreen);
	bg[1] = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, DMedgreen);
	hl = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, DPurpleblue);
	fg = display->black;
	if(bg[0] == nil || bg[1] == nil || hl == nil || fg == nil)
		sysfatal ("allocimage: %r");
	if((⌖ = initmouse(nil, screen)) == nil)
		sysfatal("initmouse: %r");
	a[RESIZE].c = ⌖->resizec;
	a[MOUSE].c = ⌖->c;
	a[MOUSE].v = &⌖->Mouse;
	if((⌨ = initkeyboard(nil)) == nil)
		sysfatal("initkeyboard: %r");
	a[KEYBOARD].c = ⌨->c;
	sendul(⌖->resizec, 1);
	while(9){switch(alt(a)){
	case RESIZE:
		resize();
		break;
	case MOUSE:
		switch(⌖->buttons){
		default:
			continue;
		case 1:
			do readmouse(⌖); while(⌖->buttons);
			if(⌖->xy.y < horiz){
				row -= 1 + (horiz - ⌖->xy.y) / font->height;
				if(row < 0)
					row = 0;
			}else{
				row += (⌖->xy.y - horiz) / font->height;
				if(row > 0x7ffffe)
					row = 0x7ffffe;
			}
			col = (⌖->xy.x - screen->r.min.x) / wid - 2;
			if(col < 0)
				col = 0;
			if(col > 18)
				col = 18;
			break;
		case 2:
			if(col == 18){
				b2m.item = b2sx;
				switch(menuhit(2, ⌖, &b2m, nil)){
				case 0: k = '\n'; goto kbdcmd;
				case 1: k = 'l'; goto kbdcmd;
				case 2: k = 'm'; goto kbdcmd;
				}
			}else{
				b2m.item = b2s;
				switch(menuhit(2, ⌖, &b2m, nil)){
				case 0: k = '\n'; goto kbdcmd;
				case 1:
					*buf = 0;
					enter("note", buf, sizeof buf, ⌖, ⌨, nil);
					b = strchr(notes, buf[0]);
					if(b == nil)
						continue;
					i = b - notes;
					if(buf[1] == '#'){
						if(buf[2] < '0' || buf[2] > '8' || buf[3])
							continue;
						i += (buf[2] - '0') * 12 + 1;
					}else if(buf[1] == 'b'){
						if(buf[2] < '0' || buf[2] > '8' || buf[3])
							continue;
						i += (buf[2] - '0') * 12 - 1;
					}else{
						if(buf[1] < '0' || buf[1] > '8' || buf[2])
							continue;
						i += (buf[1] - '0') * 12;
					}
					e = newevent(row << 8 | col << 3 | NOTE);
					fmtnote(e, i);
					insert(e);
					break;
				case 2: k = 'b'; goto kbdcmd;
				}
			}
			break;
		case 4:
			switch(menuhit(3, ⌖, &b3m, nil)){
			case 0:
				if(eds == 0){
					enter("you haven't done anything yet!", nil, 0, ⌖, ⌨, nil);
					continue;
				}
				sprint(buf, "1");
				enter("undo", buf, sizeof buf, ⌖, ⌨, nil);
				i = -atoi(buf);
				if(i == 0)
					continue;
				hist(i, 0);
				j = ed - (i > 0 && ed > 0);
				row = edit[j]->index >> 8;
				col = edit[j]->index >> 3 & 31;
				break;
			case 1: k = 'j'; goto kbdcmd;
			case 2: k = 'k'; goto kbdcmd;
			case 3: k = 'c'; goto kbdcmd;
			case 4: k = 'v'; goto kbdcmd;
			case 5: k = 's'; goto kbdcmd;
			case 6: k = 'W'; goto kbdcmd;
			case 7: k = 0; goto kbdcmd;
			}
			break;
		case 8:
			if(row < skip)
				continue;
			row -= skip;
			break;
		case 16:
			if(row + skip > 0x7ffffe)
				continue;
			row += skip;
			break;
		}
		break;
	case KEYBOARD: kbdcmd:
		switch(k){
		default:
			if(col == 18)
				continue;
			b = strchr(keys, k);
			if(b == nil)
				break;
			e = newevent(row << 8 | col << 3 | NOTE);
			fmtnote(e, oct + b - keys);
			insert(e);
			fd = startopl();
			if(fd >= 0){
				b = buf;
				t = row + 1 << 8;
				for(e = song; e != nil && e->index < t; e = e->next){
					i = e->index >> 3 & 31;
					if(i == 18 || i == col){
						b = process(e, b);
						if(b + 55 > buf + sizeof buf){
							write(fd, buf, b - buf);
							b = buf;
						}
					}
				}
				if(b > buf)
					write(fd, buf, b - buf);
				sleep(tickns * tpr / 1000000);
				close(fd);
				setcursor(⌖, nil);
			}
			if(row + skip < 0x7ffffe)
				row += skip;
			break;
		case 'a':
			if(oct < 7 * 12)
				oct += 12;
			continue;
		case 'z':
			if(oct)
				oct -= 12;
			continue;
		case 'm':
			if(col < 18){
				mute[col] ^= 0x30;
				break;
			}
			moveto(⌖, Pt(screen->r.min.x + 20 * wid, horiz + font->height));
			*buf = 0;
			if(enter("mark", buf, sizeof buf - 8, ⌖, ⌨, nil) < 1)
				continue;
			e = newevent(row << 8 | 18 << 3 | MARK);
			e->mark = strdup(buf);
			insert(e);
			break;
		case 'x':
			if(col == 18)
				break;
			e = newevent(row << 8 | col << 3 | NOTE);
			fmtnote(e, 0xff);
			insert(e);
			break;
		case 'k':
			*buf = 0;
			enter("skip", buf, 5, ⌖, ⌨, nil);
			i = atoi(buf);
			if(i < 1 || i > 999)
				continue;
			sprint(b3s[2], "skip = %d", skip = i);
			skipoff = skip - row % skip;
			break;
		case 'l':
			*buf = 0;
			enter("loop", buf, 4, ⌖, ⌨, nil);
			i = atoi(buf);
			if(i < 1 || i > 255)
				continue;
			e = newevent(row << 8 | 18 << 3 | LOOP);
			e->loop = atoi(buf) & 0xff;
			insert(e);
			break;
		case 's': case 'c':
			p = Pt(screen->r.min.x + 21 * wid, screen->r.min.y);
			draw(screen, Rect(p.x, p.y, screen->r.max.x, p.y + font->height), bg[0], nil, ZP);
			if(snarfcol < 0){
				snarfrow = row;
				snarfcol = col;
				sprint(buf, "selected %06ux-%c",
					row, col == 18 ? 'X' : 'A' + col);
				string(screen, p, fg, ZP, font, buf);
				flushimage(display, 1);
				strcpy(b3s[3], "cut");
				strcpy(b3s[5], "snarf");
				continue;
			}
			while(snarf != nil){
				e = snarf;
				snarf = snarf->next;
				if((e->index & 7) == MARK)
					free(e->mark);
				free(e);
			}
			if(snarfrow < row){
				i = row + 1 << 8;
				snarfrow <<= 8;
			}else{
				i = snarfrow + 1 << 8;
				snarfrow = row << 8;
			}
			if(snarfcol < col){
				j = col + 1 << 3;
				snarfcol <<= 3;
			}else{
				j = snarfcol + 1 << 3;
				snarfcol = col << 3;
			}
			for(e = song; e != nil && e->index < snarfrow; e = e->next)
				;
			for(ep = &snarf; e != nil && e->index < i; e = e->next)
				if((e->index & 0xf8) >= snarfcol && (e->index & 0xf8) < j){
					*ep = newevent(e->index - snarfrow - snarfcol);
					evdup(*ep, e);
					ep = &(*ep)->next;
				}
			*ep = nil;
			if(k == 'c'){
				for(ep = &song; *ep != nil && (*ep)->index < snarfrow; ep = &(*ep)->next)
					;
				while(*ep != nil && (*ep)->index < i)
					if(((*ep)->index & 0xf8) >= snarfcol && ((*ep)->index & 0xf8) < j)
						delete(*ep);
					else
						ep = &(*ep)->next;
			}
			redraw();
			sprint(buf, "%s %06ux-%c to %06ux-%c",
				k == 'c' ? "cut" : "snarfed",
				snarfrow, snarfcol == 18 ? 'X' : 'A' + snarfcol,
				row, col == 18 ? 'X' : 'A' + col);
			string(screen, p, fg, ZP, font, buf);
			flushimage(display, 1);
			strcpy(b3s[3], "select");
			strcpy(b3s[5], "select");
			snarfcol = -1;
			continue;
		case 'v':
			for(ep = &snarf; *ep != nil && row + ((*ep)->index >> 8) < 0x7fffff; ep = &(*ep)->next){
				i = col + ((*ep)->index >> 3 & 31);
				j = (*ep)->index & 7;
				if(i > 18 || i == 18 && j < GLOBAL || j >= GLOBAL && i < 18)
					continue;
				e = newevent((row << 8) + (col << 3) + (*ep)->index);
				evdup(e, *ep);
				insert(e);
			}
			break;
		case Kesc: case ',':
			if(eds == 0)
				break;
			hist(-1, 0);
			row = edit[ed]->index >> 8;
			col = edit[ed]->index >> 3 & 31;
			break;
		case '.':
			if(ed == eds)
				break;
			row = edit[ed]->index >> 8;
			col = edit[ed]->index >> 3 & 31;
			hist(1, 0);
			break;
		case 'b':
			if(col == 18)
				break;
			i = row << 8 | col << 3 | BEND;
			for(e = song; e != nil && e->index < i; e = e->next)
				;
			if(e != nil && e->index == i)
				sprint(buf, "%+d", e->bend);
			else
				*buf = 0;
			if(enter("32ths of a semitone to adjust per tick", buf, 5, ⌖, ⌨, nil) < 1)
				continue;
			e = newevent(i);
			e->bend = atoi(buf);
			if(e->bend < -128)
				e->bend = -128;
			if(e->bend > 127)
				e->bend = 127;
			insert(e);
			break;
		case Kdel:
			i = row << 8 | col << 3;
			ep = &song;
			while(*ep != nil && (*ep)->index < i)
				ep = &(*ep)->next;
			i += 8;
			while(*ep != nil && (*ep)->index < i)
				delete(*ep);
			break;
		case '\n':
			if(col == 18){
				k = 0;
				e = newevent(row << 8 | 18 << 3 | GLOBAL);
				e->next = nil;
				for(ep = &song; *ep != nil && (*ep)->index <= e->index; ep = &(*ep)->next)
					if(((*ep)->index & 255) == (e->index & 255))
						e->next = *ep;
				if(e->next != nil){ /* copy last global settings */
					e->bpm = e->next->bpm;
					e->rpb = e->next->rpb;
					e->tpr = e->next->tpr;
					e->r104 = e->next->r104;
					e->rbd = e->next->rbd;
				}else{ /* default global settings */
					e->bpm = 120;
					e->rpb = 4;
					e->tpr = 4;
					e->r104 = 0;
					e->rbd = 0;
				}
			drawglobaled:
				draw(screen, screen->r, bg[0], nil, ZP);
				p = screen->r.min;
				string(screen, p, fg, ZP, font, "Global Settings");
				p.y += font->height;
				sprint(buf, "beats per minute: %d", e->bpm);
				string(screen, p, fg, ZP, font, buf);
				p.y += font->height;
				sprint(buf, "rows per beat: %d", e->rpb);
				string(screen, p, fg, ZP, font, buf);
				p.y += font->height;
				sprint(buf, "ticks per row: %d", e->tpr);
				string(screen, p, fg, ZP, font, buf);
				for(i = j = 0; i < 3; i++, j+= 2){
					p.y += font->height;
					sprint(buf, "%c–%c paired: %d", 'A' + j, 'G' + j, e->r104 >> i & 1);
					string(screen, p, fg, ZP, font, buf);
					p.y += font->height;
					sprint(buf, "%c–%c paired: %d", 'B' + j, 'H' + j, e->r104 >> i + 3 & 1);
					string(screen, p, fg, ZP, font, buf);
				}
				p.y += font->height;
				sprint(buf, "deep tremolo: %d", e->rbd >> 7 & 1);
				string(screen, p, fg, ZP, font, buf);
				p.y += font->height;
				sprint(buf, "deep vibrato: %d", e->rbd >> 6 & 1);
				string(screen, p, fg, ZP, font, buf);
				flushimage(display, 1);
				while(k != '\n')switch(alt(a)){
				case RESIZE:
					resize();
					goto drawglobaled;
				case MOUSE:
					if(⌖->buttons != 1)
						break;
					switch((⌖->xy.y - screen->r.min.y) / font->height){
					case 1:
						sprint(buf, "%d", e->bpm);
						if(enter("BPM (assuming 4/4 time)", buf, 4, ⌖, ⌨, nil) < 1)
							break;
						i = atoi(buf);
						if(i >= 30 && i <= 285){
							e->bpm = i;
							goto drawglobaled;
						}
						enter("must be between 30 and 285", nil, 0, ⌖, ⌨, nil);
						break;
					case 2:
						sprint(buf, "%d", e->rpb);
						if(enter("rows per beat", buf, 3, ⌖, ⌨, nil) < 1)
							break;
						i = atoi(buf);
						if(i >= 1 && i <= 8){
							e->rpb = i;
							goto drawglobaled;
						}
						enter("must be between 1 and 8", nil, 0, ⌖, ⌨, nil);
						break;
					case 3:
						sprint(buf, "%d", e->tpr);
						if(enter("ticks per row", buf, 3, ⌖, ⌨, nil) < 1)
							break;
						i = atoi(buf);
						if(i >= 1 && i <= 8){
							e->tpr = i;
							goto drawglobaled;
						}
						enter("must be between 1 and 8", nil, 0, ⌖, ⌨, nil);
						break;
					case 4:
						reged(&e->r104, 1, 0);
						goto drawglobaled;
					case 5:
						reged(&e->r104, 1, 3);
						goto drawglobaled;
					case 6:
						reged(&e->r104, 1, 1);
						goto drawglobaled;
					case 7:
						reged(&e->r104, 1, 4);
						goto drawglobaled;
					case 8:
						reged(&e->r104, 1, 2);
						goto drawglobaled;
					case 9:
						reged(&e->r104, 1, 5);
						goto drawglobaled;
					case 10:
						reged(&e->rbd, 1, 7);
						goto drawglobaled;
					case 11:
						reged(&e->rbd, 1, 6);
						goto drawglobaled;
					}
				}
				insert(e);
				break;
			}
			k = 0;
			e = newevent(row << 8 | col << 3 | INSTR);
			e->next = nil;
			for(ep = &song; *ep != nil && (*ep)->index <= e->index; ep = &(*ep)->next)
				if(((*ep)->index & 255) == (e->index & 255))
					e->next = *ep;
			if(e->next != nil){ /* copy last instrument */
				e->r20 = e->next->r20;
				e->r23 = e->next->r23;
				e->r40 = e->next->r40;
				e->r43 = e->next->r43;
				e->r60 = e->next->r60;
				e->r63 = e->next->r63;
				e->r80 = e->next->r80;
				e->r83 = e->next->r83;
				e->re0 = e->next->re0;
				e->re3 = e->next->re3;
				e->rc0 = e->next->rc0;
			}else{ /* basic default instrument */
				e->r20 = 0;
				e->r23 = 0;
				e->r40 = 0x20;
				e->r43 = 0;
				e->r60 = 0xd0;
				e->r63 = 0xd0;
				e->r80 = 0x05;
				e->r83 = 0x05;
				e->re0 = 0;
				e->re3 = 0;
				e->rc0 = 0x30;
			}
			fd = startopl();
			if(fd >= 0)
				e->next = newevent(col << 3 | NOTE);
		drawinstred:
			draw(screen, screen->r, bg[0], nil, ZP);
			p = screen->r.min;
			sprint(buf, "Instrument %c", 'A' + col);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "AM Mode: %d", e->rc0 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Left Channel: %d", e->rc0 >> 4 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Right Channel: %d", e->rc0 >> 5 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Feedback: %d", e->rc0 >> 1 & 7);
			string(screen, p, fg, ZP, font, buf);
			p.x += Dx(screen->r) / 3;
			p.y = screen->r.min.y;
			string(screen, p, fg, ZP, font, "Operator 1");
			p.y += font->height;
			sprint(buf, "Tremolo: %d", e->r20 >> 7);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Vibrato: %d", e->r20 >> 6 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Sustaining: %d", e->r20 >> 5 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Env Scaling: %d", e->r20 >> 4 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Multiplier: %d", e->r20 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Attack: %d", e->r60 >> 4 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Decay: %d", e->r60 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Sustain: %d", e->r80 >> 4 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Release: %d", e->r80 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Waveform: %s", wave[e->re0]);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Attenuation/oct: %d", e->r40 >> 6);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Attenuation: %d", e->r40 & 63);
			string(screen, p, fg, ZP, font, buf);
			p.x += Dx(screen->r) / 3;
			p.y = screen->r.min.y;
			string(screen, p, fg, ZP, font, "Operator 1");
			p.y += font->height;
			sprint(buf, "Tremolo: %d", e->r23 >> 7);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Vibrato: %d", e->r23 >> 6 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Sustaining: %d", e->r23 >> 5 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Env Scaling: %d", e->r23 >> 4 & 1);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Multiplier: %d", e->r23 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Attack: %d", e->r63 >> 4 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Decay: %d", e->r63 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Sustain: %d", e->r83 >> 4 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Release: %d", e->r83 & 15);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Waveform: %s", wave[e->re3]);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Attenuation/oct: %d", e->r43 >> 6);
			string(screen, p, fg, ZP, font, buf);
			p.y += font->height;
			sprint(buf, "Attenuation: %d", e->r43 & 63);
			string(screen, p, fg, ZP, font, buf);
			flushimage(display, 1);
			if(fd >= 0)
				write(fd, buf, process(e, buf) - buf);
			while(k != '\n')switch(alt(a)){
			case RESIZE:
				resize();
				goto drawinstred;
			case MOUSE:
				if(⌖->buttons != 1)
					break;
				i = (⌖->xy.x - screen->r.min.x) * 3 / Dx(screen->r);
				j = (⌖->xy.y - screen->r.min.y) / font->height;
				if(i == 0){
					switch(j){
					case 1: reged(&e->rc0, 1, 0); goto drawinstred;
					case 2: reged(&e->rc0, 1, 4); goto drawinstred;
					case 3: reged(&e->rc0, 1, 5); goto drawinstred;
					case 4: reged(&e->rc0, 7, 1); goto drawinstred;
					}
					break;
				}
				switch(j){
				case 1: reged(i > 1 ? &e->r23 : &e->r20, 1, 7); goto drawinstred;
				case 2: reged(i > 1 ? &e->r23 : &e->r20, 1, 6); goto drawinstred;
				case 3: reged(i > 1 ? &e->r23 : &e->r20, 1, 5); goto drawinstred;
				case 4: reged(i > 1 ? &e->r23 : &e->r20, 1, 4); goto drawinstred;
				case 5: reged(i > 1 ? &e->r23 : &e->r20, 15, 0); goto drawinstred;
				case 6: reged(i > 1 ? &e->r63 : &e->r60, 15, 4); goto drawinstred;
				case 7: reged(i > 1 ? &e->r63 : &e->r60, 15, 0); goto drawinstred;
				case 8: reged(i > 1 ? &e->r83 : &e->r80, 15, 4); goto drawinstred;
				case 9: reged(i > 1 ? &e->r83 : &e->r80, 15, 0); goto drawinstred;
				case 10:
					if(i > 1)
						e->re3 = menu(e->re3, wave, 1);
					else
						e->re0 = menu(e->re0, wave, 1);
					goto drawinstred;
				case 11: reged(i > 1 ? &e->r43 : &e->r40, 3, 6); goto drawinstred;
				case 12: reged(i > 1 ? &e->r43 : &e->r40, 63, 0); goto drawinstred;
				}
				break;
			case KEYBOARD:
				if(fd >= 0)switch(k){
				default:
					b = strchr(keys, k);
					if(b == nil)
						break;
					fmtnote(e->next, b - keys + oct);
					write(fd, buf, process(e->next, buf) - buf);
					break;
				case 'x': case Kesc:
					fmtnote(e->next, 0xff);
					write(fd, buf, process(e->next, buf) - buf);
					break;
				case 'a':
					if(oct < 7 * 12)
						oct += 12;
					break;
				case 'z':
					if(oct)
						oct -= 12;
					break;
				}
				break;
			}
			if(fd >= 0){
				close(fd);
				free(e->next);
				setcursor(⌖, nil);
			}
			insert(e);
			break;
		case 'j':
			*buf = 0;
			if(enter("jump to mark or row", buf, sizeof buf, ⌖, ⌨, nil) < 1)
				continue;
			e = song;
			while(e != nil && ((e->index & 7) != MARK || strcmp(buf, e->mark)))
				e = e->next;
			row = e == nil ? strtoul(buf, nil, 16) : e->index >> 8;
			if(row > 0x7ffffe)
				row = 0x7ffffe;
			break;
		case Khome:
			row = 0;
			break;
		case Kend:
			if(song == nil)
				row = 0;
			else{
				for(e = song; e->next != nil; e = e->next)
					;
				row = e->index >> 8;
			}
			break;
		case Kleft:
			col = col ? col - 1 : 18;
			break;
		case Kright:
			col = col == 18 ? 0 : col + 1;
			break;
		case Kup:
			if(row < skip)
				continue;
			row -= skip;
			break;
		case Kdown:
			if(row + skip > 0x7ffffe)
				continue;
			row += skip;
			break;
		case Kpgup: /* jump to last event in this column */
			i = row << 8;
			j = 0;
			for(e = song; e != nil && e->index < i; e = e->next)
				if((e->index >> 3 & 31) == col)
					j = e->index;
			row = j >> 8;
			break;
		case Kpgdown:
			i = row + 1 << 8;
			for(e = song; e != nil && e->index < i; e = e->next)
				;
			while(e != nil && (e->index >> 3 & 31) != col)
				e = e->next;
			if(e != nil)
				row = e->index >> 8;
			break;
		case ' ':
			fd = startopl();
			if(fd < 0){
				seprint(buf, buf + sizeof buf, "opl pipeline: %r");
				enter(buf, nil, 0, ⌖, ⌨, nil);
				break;
			}
			a[NOTHING].op = CHANNOBLK;
			j = row;
			e = song;
			loopend = -1;
			looping = 0;
			for(row = 0; e != nil && row < j; row++){
				for(b = buf; e != nil && (e->index >> 8) == row; e = e->next){
					for(i = 0; i < 18; i++)
						bend[i] = 0;
					b = process(e, b);
					for(i = 0; i < 18; i++)
						bend[i] *= tpr;
					b = bends(b);
				}
				if(b > buf)
					write(fd, buf, b - buf);
				if(looping && row == loopend){
					i = loopstart << 8;
					for(e = song; e != nil && e->index < i; e = e->next)
						;
					row = loopstart - 1;
				}
			}
			t = nsec();
			while(e != nil)switch(alt(a)){
			case RESIZE:
				resize();
				redraw();
				break;
			case KEYBOARD:
				switch(k){
				default:
					if(col == 18 || (b = strchr(keys, k)) == nil)
						break;
					e = newevent(row << 8 | col << 3 | NOTE);
					fmtnote(e, b - keys + oct);
					write(fd, buf, process(e, buf) - buf);
					insert(e);
					break;
				case 'x':
					if(col == 18)
						break;
					e = newevent(row << 8 | col << 3 | NOTE);
					fmtnote(e, 0xff);
					write(fd, buf, process(e, buf) - buf);
					insert(e);
					break;
				case Kesc:
					j = row;
				case ' ':
					e = nil;
					break;
				case 'a':
					if(oct < 7 * 12)
						oct += 12;
					break;
				case 'z':
					if(oct)
						oct -= 12;
					break;
				case 'm':
					if(col == 18)
						break;
					mute[col] ^= 0x30;
					buf[0] = 0xc0 | col >> 1;
					buf[1] = col & 1;
					buf[2] = rc0[col] & ~mute[col];
					buf[3] = buf[4] = 0;
					write(fd, buf, 5);
					break;
				case Kleft:
					col = col ? col - 1 : 18;
					break;
				case Kright:
					col = col == 18 ? 0 : col + 1;
					break;
				}
				break;
			case NOTHING:
				for(i = 0; i < 18; i++)
					bend[i] = 0;
				for(b = buf; e != nil && (e->index >> 8) == row; e = e->next)
					b = process(e, b);
				if(b > buf)
					write(fd, buf, b - buf);
				redraw();
				for(k = 0; k < tpr; k++){
					t += tickns;
					i = (t - nsec()) / 1000000;
					if(i > 1)
						sleep(i);
					b = bends(buf);
					if(b > buf)
						write(fd, buf, b - buf);
				}
				if(looping && row == loopend){
					i = loopstart << 8;
					for(e = song; e != nil && e->index < i; e = e->next)
						;
					row = loopstart;
				}else
					row++;
				break;
			}
			close(fd);
			row = j;
			a[NOTHING].op = CHANEND;
			setcursor(⌖, nil);
			break;
		case 'W':
			if(path == nil)
				*buf = 0;
			else
				strcpy(buf, path);
			if(enter("write", buf, sizeof buf, ⌖, ⌨, nil) < 1)
				continue;
			fd = create(buf, OWRITE, 0666);
			if(fd < 0){
				seprint(buf, buf + sizeof buf, "create failed: %r");
				enter(buf, nil, 0, ⌖, ⌨, nil);
				continue;
			}
			if(path == nil || strcmp(buf, path)){
				if(path != argv[1])
					free(path);
				path = strdup(buf);
				j = open("/dev/label", OWRITE);
				if(j >= 0){
					fprint(j, "%s %s", argv[0], path);
					close(j);
				}
			}
			e = song;
			t = 0x100;
			while(9){
				b = buf;
				while(e != nil){
					while(t < e->index && b < buf + sizeof buf){
						*b++ = NEXTROW;
						t += 0x100;
					}
					switch(e->index & 7){
					case INSTR:
						if(b + 12 > buf + sizeof buf)
							break;
						b[0] = e->index;
						b[1] = e->r20; b[2] = e->r23;
						b[3] = e->r40; b[4] = e->r43;
						b[5] = e->r60; b[6] = e->r63;
						b[7] = e->r80; b[8] = e->r83;
						b[9] = e->re0; b[10] = e->re3;
						b[11] = e->rc0;
						b += 12;
						e = e->next;
						continue;
					case NOTE:
						if(b + 2 > buf + sizeof buf)
							break;
						b[0] = e->index;
						b[1] = e->note[0] == 'x' ? 0xff : e->freq / 32 + 57 - 19 * 12;
						b += 2;
						e = e->next;
						continue;
					case BEND:
						if(b + 2 > buf + sizeof buf)
							break;
						b[0] = e->index;
						b[1] = e->bend;
						b += 2;
						e = e->next;
						continue;
					case GLOBAL:
						if(b + 5 > buf + sizeof buf)
							break;
						b[0] = e->index;
						b[1] = e->bpm - 30;
						b[2] = e->tpr - 1 << 4 | e-> rpb - 1;
						b[3] = e->r104;
						b[4] = e->rbd;
						b += 5;
						e = e->next;
						continue;
					case LOOP:
						if(b + 2 > buf + sizeof buf)
							break;
						b[0] = e->index;
						b[1] = e->loop;
						b += 2;
						e = e->next;
						continue;
					case MARK:
						if(b + strlen(e->mark) + 2 > buf + sizeof buf)
							break;
						b[0] = e->index;
						strcpy(b + 1, e->mark);
						b = strchr(b, 0) + 1;
						t += 0x100;
						e = e->next;
						continue;
					}
					break;
				}
				if(b == buf)
					break;
				if(write(fd, buf, b - buf) != b - buf){
					close(fd);
					seprint(buf, buf + sizeof buf, "write: %r");
					enter(buf, nil, 0, ⌖, ⌨, nil);
					continue;
				}
			}
			close(fd);
			continue;
		case 'Q': case Keof: case 0:
			j = k;
			setcursor(⌖, &skull);
			do i = alt(a);
				while(i == MOUSE && ⌖->buttons == 0);
			if(j == 0 && i == MOUSE && ⌖->buttons == 4
			|| i == KEYBOARD && j == k)
				threadexitsall(nil);
			setcursor(⌖, nil);
			continue;
		}
		break;
	}redraw();}
}