1 files changed, 324 insertions, 0 deletions
diff --git a/lhist_scr.c b/lhist_scr.c
new file mode 100644
index 0000000..c09e48e
--- /dev/null
+++ b/lhist_scr.c
@@ -0,0 +1,324 @@
+/*
+ * wavemon - a wireless network monitoring aplication
+ *
+ * Copyright (c) 2001-2002 Jan Morgenstern <jan@jm-music.de>
+ *
+ * wavemon is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2, or (at your option) any later
+ * version.
+ *
+ * wavemon is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with wavemon; see the file COPYING.  If not, write to the Free Software
+ * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#include "iw_if.h"
+
+/* CONSTANTS */
+
+/* Number of lines in the key window at the bottom */
+#define KEY_WIN_HEIGHT	3
+
+/* Total number of lines in the histogram window */
+#define HIST_WIN_HEIGHT	(WAV_HEIGHT - KEY_WIN_HEIGHT)
+
+/*
+ * Analogous to MAXYLEN, the following sets both the
+ * - highest y/line index and the
+ * - total count of lines inside the histogram window.
+ */
+#define HIST_MAXYLEN	(HIST_WIN_HEIGHT - 1)
+
+/* GLOBALS */
+static WINDOW *w_lhist, *w_key;
+
+/*
+ *	Keeping track of global minima/maxima
+ */
+static struct iw_extrema {
+	bool	initialised;
+	float	min;
+	float	max;
+} e_signal, e_noise, e_snr;
+
+static void init_extrema(struct iw_extrema *ie)
+{
+	memset(ie, 0, sizeof(*ie));
+}
+
+static void track_extrema(const float new_sample, struct iw_extrema *ie)
+{
+	if (! ie->initialised) {
+		ie->initialised = true;
+		ie->min = ie->max = new_sample;
+	} else if (new_sample < ie->min) {
+		ie->min = new_sample;
+	} else if (new_sample > ie->max) {
+		ie->max = new_sample;
+	}
+}
+
+static char *fmt_extrema(const struct iw_extrema *ie, const char *unit)
+{
+	static char range[256];
+
+	if (! ie->initialised)
+		snprintf(range, sizeof(range), "unknown");
+	else if (ie->min == ie->max)
+		snprintf(range, sizeof(range), "%+.0f %s", ie->min, unit);
+	else
+		snprintf(range, sizeof(range), "%+.0f..%+.0f %s", ie->min,
+								ie->max, unit);
+	return range;
+}
+
+/*
+ * Simple array-based circular FIFO buffer
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * Insertion works from lower to higher indices.
+ * Access works from higher down to lower indices.
+ *
+ * Cases & assumptions:
+ * ~~~~~~~~~~~~~~~~~~~~
+ * - principle: unsigned counter + hash function to handle array wrap-around;
+ * - buffer is empty if count == 0;
+ * - else count indicates the next place to insert(modulo %IW_STACKSIZE).
+ */
+#define IW_STACKSIZE		1024
+static struct iw_levelstat	iw_stats_cache[IW_STACKSIZE];
+static uint32_t			count;
+#define COUNTMAX		(typeof(count))-1
+
+static void iw_cache_insert(const struct iw_levelstat new)
+{
+	iw_stats_cache[count % IW_STACKSIZE] = new;
+	/*
+	 * Handle counter overflow by mapping into a smaller index which is
+	 * identical (modulo %IW_STACKSIZE) to the old value. (The datatype
+	 * of 'count' must be able to express at least 2 * IW_STACKSIZE.)
+	 */
+	if (++count == COUNTMAX)
+		count = IW_STACKSIZE + (COUNTMAX % IW_STACKSIZE);
+}
+
+static struct iw_levelstat iw_cache_get(const uint32_t index)
+{
+	struct iw_levelstat zero = IW_LSTAT_INIT;
+
+	if (index > IW_STACKSIZE || index > count)
+		return zero;
+	return iw_stats_cache[(count - index) % IW_STACKSIZE];
+}
+
+void iw_cache_update(struct iw_stat *iw)
+{
+	static struct iw_levelstat prev, avg = IW_LSTAT_INIT;
+	static int slot;
+
+	if (! (iw->stat.qual.updated & IW_QUAL_LEVEL_INVALID)) {
+		avg.flags  &= ~IW_QUAL_LEVEL_INVALID;
+		avg.signal += iw->dbm.signal / conf.slotsize;
+		track_extrema(iw->dbm.signal, &e_signal);
+	}
+
+	if (! (iw->stat.qual.updated & IW_QUAL_NOISE_INVALID)) {
+		avg.flags &= ~IW_QUAL_NOISE_INVALID;
+		avg.noise += iw->dbm.noise / conf.slotsize;
+		track_extrema(iw->dbm.noise, &e_noise);
+		track_extrema(iw->dbm.signal - iw->dbm.noise, &e_snr);
+	}
+
+	if (++slot >= conf.slotsize) {
+		iw_cache_insert(avg);
+
+		if (conf.lthreshold_action &&
+		    prev.signal < conf.lthreshold &&
+		    avg.signal >= conf.lthreshold)
+			threshold_action(conf.lthreshold);
+		else if (conf.hthreshold_action &&
+			 prev.signal > conf.hthreshold &&
+			 avg.signal <= conf.hthreshold)
+			threshold_action(conf.hthreshold);
+
+		prev = avg;
+		avg.signal = avg.noise = slot = 0;
+		avg.flags  = IW_QUAL_LEVEL_INVALID | IW_QUAL_NOISE_INVALID;
+	}
+}
+
+/*
+ * Histogram-specific display functions
+ */
+static double hist_level(double val, int min, int max)
+{
+	return map_range(val, min, max, 1, HIST_MAXYLEN);
+}
+
+/* Order needs to be reversed as y-coordinates grow downwards */
+static int hist_y(int yval)
+{
+	return reverse_range(yval, 1, HIST_MAXYLEN);
+}
+
+/* Values come in from the right, so 'x' also needs to be reversed */
+static int hist_x(int xval)
+{
+	return reverse_range(xval, 1, MAXXLEN);
+}
+
+/* plot single values, without clamping to min/max */
+static void hist_plot(double yval, int xval, enum colour_pair plot_colour)
+{
+	double level, fraction;
+	chtype ch;
+
+	fraction = modf(yval, &level);
+
+	if (in_range(level, 1, HIST_MAXYLEN)) {
+		/*
+		 * The 5 different scanline chars provide a pretty good accuracy.
+		 * ncurses will fall back to standard ASCII chars anyway if they
+		 * are not available.
+		 */
+		if (fraction < 0.2)
+			ch = ACS_S9;
+		else if (fraction < 0.4)
+			ch = ACS_S7;
+		else if (fraction < 0.6)
+			ch = ACS_HLINE;
+		else if (fraction < 0.8)
+			ch = ACS_S3;
+		else
+			ch = ACS_S1;
+
+		wattrset(w_lhist, COLOR_PAIR(plot_colour) | A_BOLD);
+		mvwaddch(w_lhist, hist_y(level), hist_x(xval), ch);
+	}
+}
+
+static void display_lhist(void)
+{
+	struct iw_levelstat iwl;
+	double snr_level, noise_level, sig_level;
+	enum colour_pair plot_colour;
+	int x, y;
+
+	for (x = 1; x <= MAXXLEN; x++) {
+
+		iwl = iw_cache_get(x);
+
+		/* Clear screen and set up horizontal grid lines */
+		wattrset(w_lhist, COLOR_PAIR(CP_STATBKG));
+		for (y = 1; y <= HIST_MAXYLEN; y++)
+			mvwaddch(w_lhist, hist_y(y), hist_x(x), y % 5 ? ' ' : '-');
+
+		/*
+		 * SNR comes first, as it determines the background. If either
+		 * noise or signal is invalid, set level below minimum value to
+		 * indicate that no background is present.
+		 */
+		if (iwl.flags & (IW_QUAL_NOISE_INVALID | IW_QUAL_LEVEL_INVALID)) {
+			snr_level = 0;
+		} else {
+			snr_level = hist_level(iwl.signal - iwl.noise,
+					       conf.sig_min - conf.noise_max,
+					       conf.sig_max - conf.noise_min);
+
+			wattrset(w_lhist, COLOR_PAIR(CP_STATSNR));
+			for (y = 1; y <= clamp(snr_level, 1, HIST_MAXYLEN); y++)
+				mvwaddch(w_lhist, hist_y(y), hist_x(x), ' ');
+		}
+
+		if (! (iwl.flags & IW_QUAL_NOISE_INVALID)) {
+			noise_level = hist_level(iwl.noise, conf.noise_min, conf.noise_max);
+			plot_colour = noise_level > snr_level ? CP_STATNOISE : CP_STATNOISE_S;
+			hist_plot(noise_level, x, plot_colour);
+		}
+
+		if (! (iwl.flags & IW_QUAL_LEVEL_INVALID)) {
+			sig_level   = hist_level(iwl.signal, conf.sig_min, conf.sig_max);
+			plot_colour = sig_level > snr_level ? CP_STATSIG : CP_STATSIG_S;
+			hist_plot(sig_level, x, plot_colour);
+		}
+	}
+
+	wrefresh(w_lhist);
+}
+
+static void display_key(WINDOW *w_key)
+{
+	/* Clear the (one-line) screen) */
+	wmove(w_key, 1, 1);
+	wclrtoborder(w_key);
+
+	wattrset(w_key, COLOR_PAIR(CP_STANDARD));
+	waddch(w_key, '[');
+	wattrset(w_key, COLOR_PAIR(CP_STATSIG));
+	waddch(w_key, ACS_HLINE);
+	wattrset(w_key, COLOR_PAIR(CP_STANDARD));
+
+	wprintw(w_key, "] sig lvl (%s)  [", fmt_extrema(&e_signal, "dBm"));
+
+	wattrset(w_key, COLOR_PAIR(CP_STATNOISE));
+	waddch(w_key, ACS_HLINE);
+	wattrset(w_key, COLOR_PAIR(CP_STANDARD));
+
+	wprintw(w_key, "] ns lvl (%s)  [", fmt_extrema(&e_noise, "dBm"));
+
+	wattrset(w_key, COLOR_PAIR(CP_STATSNR));
+	waddch(w_key, ' ');
+
+	wattrset(w_key, COLOR_PAIR(CP_STANDARD));
+	wprintw(w_key, "] S-N ratio (%s)", fmt_extrema(&e_snr, "dB"));
+
+	wrefresh(w_key);
+}
+
+static void redraw_lhist(void)
+{
+	static int vcount = 1;
+
+	if (!--vcount) {
+		vcount = conf.slotsize;
+		display_lhist();
+		display_key(w_key);
+	}
+}
+
+enum wavemon_screen scr_lhist(WINDOW *w_menu)
+{
+	int key = 0;
+
+	w_lhist = newwin_title(0, HIST_WIN_HEIGHT, "Level histogram", true);
+	w_key   = newwin_title(HIST_MAXYLEN + 1, KEY_WIN_HEIGHT, "Key", false);
+
+	init_extrema(&e_signal);
+	init_extrema(&e_noise);
+	init_extrema(&e_snr);
+
+	display_key(w_key);
+
+	iw_stat_redraw = redraw_lhist;
+	while (key < KEY_F(1) || key > KEY_F(10)) {
+		while ((key = wgetch(w_menu)) <= 0)
+			usleep(5000);
+
+		/* Keyboard shortcuts */
+		if (key == 'q')
+			key = KEY_F(10);
+		else if (key == 'i')
+			key = KEY_F(1);
+	}
+	iw_stat_redraw = NULL;
+
+	delwin(w_lhist);
+	delwin(w_key);
+
+	return key - KEY_F(1);
+}