From f99b62636f4bb625eb45cafe422cf4b8318f93a3 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Wed, 30 Jan 2013 23:16:42 -0300
Subject: [PATCH] ubb-la/gui.c: label channels

---
 ubb-la/gui.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff --git a/ubb-la/gui.c b/ubb-la/gui.c
index 9a94be7..bc8fb68 100644
--- a/ubb-la/gui.c
+++ b/ubb-la/gui.c
@@ -10,11 +10,17 @@
  * (at your option) any later version.
  */
 
+#ifndef	_GNU_SOURCE
+#define	_GNU_SOURCE	/* for vasprintf */
+#endif
+
+#include <stdarg.h>
 #include <stdint.h>
 #include <stdlib.h>
 
 #include "SDL.h"
 #include "SDL_gfxPrimitives.h"
+#include "SDL_gfxPrimitives_font.h"
 
 #include "gui.h"
 
@@ -29,8 +35,9 @@
 #define XRES	320	/* canvas width */
 #define YRES	240	/* canvas height */
 
-#define	LEVEL_RGBA	0xffff00ff
-#define	BOUNCE_RGBA	0xff8080ff
+#define	LEVEL_RGBA	0xffff00ff	/* constant level or single change */
+#define	BOUNCE_RGBA	0xff8080ff	/* bouncing signal */
+#define	LABEL_RGBA	0xffffffff	/* channel label */
 
 #define	CH_XOFF		30
 #define	CH_YOFF		30
@@ -80,6 +87,41 @@ static void update(void)
 }
 
 
+/* ----- Text output ------------------------------------------------------- */
+
+
+/*
+ * stringColor from SDL_gfx fails for some reason. SDL_ttf is just too much
+ * compatibility trouble. So we do our own.
+ */
+
+static void textf(int x, int y, uint32_t color, const char *fmt, ...)
+{
+	va_list ap;
+	char *s;
+	uint8_t *p;
+	int ix, iy;
+	int res;
+
+	va_start(ap, fmt);
+	res = vasprintf(&s, fmt, ap);
+	va_end(ap);
+	(void) res;
+
+	while (*s) {
+		p = gfxPrimitivesFontdata+(*s << 3);
+		for (iy = 0; iy != 8; iy++) {
+			for (ix = 0; ix != 8; ix++)
+				if ((*p << ix) & 0x80)
+					pixelColor(surf, x+ix, y+iy, color);
+			p++;
+		}
+		x += 8;
+		s++;
+	}
+}
+
+
 /* ----- Waveform elements ------------------------------------------------- */
 
 
@@ -237,12 +279,15 @@ void gui(const uint8_t *buf, int skip, int nibbles)
 	int pos = (skip+nibbles) >> 1;
 	int zoom;	/* < 0: zoom out; 0: 1 pixel = 1 sample; > 1: zoom in */
 	int min_zoom = 0;
+	int i;
 
 	while (XRES-CH_XOFF < (nibbles-skip) >> -min_zoom)
 		min_zoom--;
 	zoom = min_zoom;
 	while (1) {
 		clear();
+		for (i = 0; i != 4; i++)
+			textf(0, ch_y(i, 1), LABEL_RGBA, "CH%d", i);
 		show_buffer(buf, skip, nibbles, CH_XOFF, XRES, zoom, pos);
 		update();