shithub: neindaw

ref: 11bee08c7da60c752092e5ada1ede8a9dc916a68
dir: neindaw/util.c

#include <u.h>
#include <libc.h>
#include <tos.h>

int usensec = 0;

static int b2i[255] = {
	['0'] =  0,  1,  2,  3,  4,  5,  6,  7,  8,  9,
	['a'] = 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
	['k'] = 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
	['u'] = 30, 31, 32, 33, 34, 35,
	['A'] = 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
	['K'] = 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
	['U'] = 30, 31, 32, 33, 34, 35,
};

static float notes[/* octave */]['g'-'A'+1 /* note */] = {
#include "a440.h"
};

int
i36(uchar c)
{
	return b2i[c];
}

float
note2freq(uchar note, uchar octave)
{
	note -= 'A';
	octave -= '0';
	if (octave >= nelem(notes) || note >= nelem(notes[0]))
		return 0.0;
	return notes[octave][note];
}

int
pathopen(char *path, char *fmt, ...)
{
	va_list arg;
	char *s;
	int fd;

	va_start(arg, fmt);
	s = vsmprint(fmt, arg);
	va_end(arg);

	if (s == nil || (path = smprint("%s/%s", path, s)) == nil)
		sysfatal("memory");
	free(s);
	if ((fd = open(path, OWRITE)) < 0)
		fprint(2, "%s: %r\n", path);
	free(path);

	return fd;
}

/*
 * nsec() is wallclock and can be adjusted by timesync
 * so need to use cycles() instead, but fall back to
 * nsec() in case we can't
 */
uvlong
nanosec(void)
{
	static uvlong fasthz, xstart;
	uvlong x, div;

	if(fasthz == ~0ULL)
		return nsec() - xstart;

	if(fasthz == 0){
		fasthz = _tos->cyclefreq;
		if(fasthz == 0){
			fasthz = ~0ULL;
			xstart = nsec();
			fprint(2, "cyclefreq not available, falling back to nsec()\n");
			fprint(2, "you might want to disable aux/timesync\n");
			return 0;
		}
		cycles(&xstart);
		return 0;
	}
	cycles(&x);
	x -= xstart;

	/* this is ugly */
	for(div = 1000000000ULL; x < 0x1999999999999999ULL && div > 1 ; div /= 10ULL, x *= 10ULL);

	return x / (fasthz / div);
}