alsa-visual/spark_ncurses.c

#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <ncurses.h>
#include <sys/ioctl.h>
#include <ctype.h>
#include <math.h>

#define NARGS 4096
#define ARG_SIZE 50
#define MAX 1000000
#define MIN 50000

int args;
double values[NARGS + 1];

struct winsize ws;

int parse_double(const char *str, double *res) {
	char *ptr;

	*res = strtod(str, &ptr);
	if (*ptr)
		return 0;

	return 1;
}

int add_value(const char *str) {
	if (args >= sizeof(values) / sizeof(double) || args > ws.ws_col)
		return 1;

	double val = 0;
	if (!parse_double(str, &val))
		return 1;

	values[args] = val;
	args++;

	return 0;
}

void stdin_read(void) {
	char arg[ARG_SIZE + 1];
	char *p = arg;

	fflush(stdin);
	while (1) {
		int c = getchar();
		if (c == EOF)
			return;

		else if (c == ' ' && p != arg) {
			*p = '\0';
			p = arg;

			if (add_value(arg))
				break;
		}

		else {
			*p = c;
			if (p + 1 == arg + sizeof(arg))
				break;

			p++;
		}
	}
}

void mvprint(int y, int x, int lvl) {
	char *fmt = "@";
	if (lvl < 4) {
		fmt = "/";
		if (y > ws.ws_row / 2)
			fmt = "\\";
	}

	else if (lvl - 4 <= 2)
		fmt = "+";

	mvprintw(y, x, "%s", fmt);
}

void print(double value, double diff, int col) {
	size_t m_screen = ws.ws_row / 2;

	if (value >= 0) {
		int lvl = (int)round((value - MIN + 1) / diff * 2);
		mvprint(m_screen - lvl, col, lvl);
	}

	else {
		int lvl = (int)round(((value * -1) - MIN + 1) / diff * 2);
		mvprint(m_screen + lvl, col, lvl);
	}
}

void sig_handler(int sig) {
	(void)sig;

	endwin();
	exit(0);
}

int main(void) {
	signal(SIGINT, sig_handler);
	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) < 0)
		return 1;

	initscr();
	curs_set(0);
	timeout(0);

	double diff = MAX - MIN + 1;
	if (diff < 1)
		diff = 1;

	while (1) {
		args = 0;
		stdin_read();

		clear();
		for (int i = 1; i < args - 1; i++)
			print((values[i - 1] + values[i] + values[i + 1]) / 4, diff, i);

		refresh();
	}
}