From e1be0f242b37e1f3c102791482e9d94f2929f8eb Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Wed, 30 Jan 2013 23:37:05 -0300
Subject: [PATCH] ubb-la/gui.c: display a small map of buffer and view

---
 ubb-la/gui.c | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/ubb-la/gui.c b/ubb-la/gui.c
index bc8fb68..990fafa 100644
--- a/ubb-la/gui.c
+++ b/ubb-la/gui.c
@@ -35,10 +35,19 @@
 #define XRES	320	/* canvas width */
 #define YRES	240	/* canvas height */
 
+#define	MAP_BUF_RGBA	0x808080ff	/* buffer in the map */
+#define	MAP_VIEW_RGBA	0xffffffff	/* current view in the map */
 #define	LEVEL_RGBA	0xffff00ff	/* constant level or single change */
 #define	BOUNCE_RGBA	0xff8080ff	/* bouncing signal */
 #define	LABEL_RGBA	0xffffffff	/* channel label */
 
+#define	XCENTER		((XRES+CH_XOFF)/2)
+
+#define	MAP_BUF_Y0	2
+#define	MAP_BUF_Y1	8
+#define	MAP_VIEW_Y0	0
+#define	MAP_VIEW_Y1	10
+
 #define	CH_XOFF		30
 #define	CH_YOFF		30
 #define	CH_SKIP		16
@@ -122,6 +131,26 @@ static void textf(int x, int y, uint32_t color, const char *fmt, ...)
 }
 
 
+/* ----- Map of buffer and view -------------------------------------------- */
+
+
+static void show_map(int skip, int nibbles, int s0, int s1)
+{
+	int w = nibbles-skip;
+	int m = (nibbles+skip) >> 1;
+	int scale = 0;
+
+	while (w >= (XRES-CH_XOFF)/2) {
+		w >>= 1;
+		scale++;
+	}
+	boxColor(surf, XCENTER-(w >> 1), MAP_BUF_Y0,
+	    XCENTER+(w >> 1), MAP_BUF_Y1, MAP_BUF_RGBA);
+	rectangleColor(surf, (s0-m+(XCENTER << scale)) >> scale, MAP_VIEW_Y0,
+	    (s1-m+(XCENTER << scale)) >> scale, MAP_VIEW_Y1, MAP_VIEW_RGBA);
+}
+
+
 /* ----- Waveform elements ------------------------------------------------- */
 
 
@@ -227,12 +256,14 @@ static void show_buffer_zoom_out(const uint8_t *buf, int skip, int nibbles,
 static void show_buffer(const uint8_t *buf, int skip, int nibbles,
     int x0, int x1, int zoom, int pos)
 {
-	int xm, w, p0, p1;
+	int xm, w, s, p0, p1;
 	int d, dp;
 
 	xm = (x0+x1) >> 1;
 	dp = pos-((nibbles+skip) >> 1);
 	if (zoom < 0) {
+		s = (x1-x0) << -zoom;
+		show_map(skip, nibbles, pos-s/2, pos+s/2);
 		w = (nibbles-skip) >> -zoom;
 		p0 = xm-(w >> 1)-(dp >> -zoom);
 		p1 = xm+((w+1) >> 1)-(dp >> -zoom);
@@ -246,6 +277,8 @@ static void show_buffer(const uint8_t *buf, int skip, int nibbles,
 		}
 		show_buffer_zoom_out(buf, skip, nibbles, p0, p1);
 	} else {
+		s = (x1-x0) >> zoom;
+		show_map(skip, nibbles, pos-s/2, pos+s/2);
 		w = (nibbles-skip) << zoom;
 		p0 = xm-(w >> 1)-(dp << zoom);
 		p1 = xm+((w+1) >> 1)-(dp << zoom);