ubb-la/gui.c: add user-defined zero reference (set/unset with space)

ubb-la/gui.c

@@ -41,6 +41,7 @@
 #define	MAP_BUF_RGBA	0x808080ff	/* buffer in the map */
 #define	MAP_VIEW_RGBA	0xffffffff	/* current view in the map */
 #define	CENTER_RGBA	0x5080ffff	/* center marker */
+#define	USER_REF_RGBA	0x00ff40ff	/* user reference marker */
 #define	LEVEL_RGBA	0xffff00ff	/* constant level or single change */
 #define	BOUNCE_RGBA	0xff8080ff	/* bouncing signal */
 #define	LABEL_RGBA	0xffffffff	/* channel label */
@@ -60,7 +61,11 @@
 
 #define	CENTER_W	8
 #define	CENTER_Y0	20
-#define	CENTER_Y1	24
+#define	CENTER_Y1	(CENTER_Y0+4)
+
+#define	USER_REF_W	8
+#define	USER_REF_Y0	92
+#define	USER_REF_Y1	(USER_REF_Y0+4)
 
 #define	CH_XOFF		30
 #define	CH_YOFF		30
@@ -74,8 +79,8 @@
 
 #define	UNIT_GAP	2		/* space between number and unit */
 
-#define	POS_T_X		176
+#define	POS_T_X		182
-#define	POS_SAMP_X	264
+#define	POS_SAMP_X	270
 #define	POS_Y		(MEAS_DIV_Y-8-3)
 
 #define	MEAS_DIV_Y	(FREQ_Y-3-1)
@@ -89,6 +94,13 @@
 #define	DIV_INT_X	80
 #define	DIV_INT_Y	INTERVAL_Y
 
+#define	USER_T_X	POS_T_X
+#define	USER_T_Y	FREQ_Y
+#define	USER_SAMP_X	POS_SAMP_X
+#define	USER_SAMP_Y	USER_T_Y
+#define	USER_FREQ_X	POS_T_X
+#define	USER_FREQ_Y	(USER_T_Y+8+2)
+
 
 /* ----- Miscellaneous definitions ----------------------------------------- */
 
@@ -97,6 +109,7 @@
 #define	REPEAT_INTERVAL_MS	30
 
 static SDL_Surface *surf;
+static int user_ref = -1;
 
 
 /* ----- SDL initialization and screen-wide functions ---------------------- */
@@ -294,14 +307,25 @@ static void show_buffer_zoom_out(const uint8_t *buf, int skip, int nibbles,
 }
 
 
+static void user_ref_marker(int x0, int x1, int x)
+{
+	if (x < 0 || x > x1-x0)
+		return;
+	filledTrigonColor(surf, x0+x, USER_REF_Y0,
+	    x0+x-USER_REF_W/2, USER_REF_Y1,
+	    x0+x+USER_REF_W/2, USER_REF_Y1, USER_REF_RGBA);
+}
+
+
 static void show_buffer(const uint8_t *buf, int skip, int nibbles,
     int x0, int x1, int zoom, int pos)
 {
 	int xm, w, s, p0, p1;
-	int d, dp;
+	int d, dp, ref;
 
 	xm = (x0+x1) >> 1;
 	dp = pos-((nibbles-skip) >> 1);
+	ref = user_ref+skip;
 	DEBUG("show: %d-%d Sa; %d-%d pix; pos %d dp %d; xm %d xcenter %d\n",
 	    skip, nibbles, x0, x1, pos, dp, xm, XCENTER);
 	if (zoom < 0) {
@@ -319,6 +343,8 @@ static void show_buffer(const uint8_t *buf, int skip, int nibbles,
 			p1 = x1;
 		}
 		show_buffer_zoom_out(buf, skip, nibbles, p0, p1);
+		if (user_ref != -1)
+			user_ref_marker(p0, p1, (ref-skip) >> -zoom);
 	} else {
 		s = (x1-x0) >> zoom;
 		show_map(skip, nibbles, pos-s/2, pos+s/2);
@@ -336,6 +362,8 @@ static void show_buffer(const uint8_t *buf, int skip, int nibbles,
 			p1 -= d << zoom;
 		}
 		show_buffer_zoom_in(buf, skip, nibbles, p0, p1);
+		if (user_ref != -1)
+			user_ref_marker(p0, p1, (ref-skip) << zoom);
 	}
 }
 
@@ -404,6 +432,20 @@ static void show_position(double freq, int pos)
 }
 
 
+static void show_user_ref(double freq, int pos, int user_ref)
+{
+	si_text(USER_T_X, USER_T_Y, fabs(user_ref-pos)/freq, "s", 7);
+
+	textf(USER_SAMP_X,USER_SAMP_Y, TEXT_RGBA, "%4d",
+	    pos > user_ref ? pos-user_ref : user_ref-pos);
+	textf(USER_SAMP_X+4*8+UNIT_GAP, USER_SAMP_Y, UNIT_RGBA, "Sa", div);
+
+	if (pos != user_ref)
+		si_text(USER_FREQ_X, USER_FREQ_Y,
+		    freq/fabs(user_ref-pos), "Hz", 7);
+}
+
+
 /* ----- Show divisions ---------------------------------------------------- */
 
 
@@ -450,6 +492,8 @@ void gui(const uint8_t *buf, int skip, int nibbles, double freq)
 		show_buffer(buf, skip, nibbles, CH_XOFF, XRES, zoom, pos);
 		show_freq(freq, zoom);
 		show_position(freq, pos);
+		if (user_ref != -1)
+			show_user_ref(freq, pos, user_ref);
 		update();
 
 		while (1) {
@@ -475,6 +519,12 @@ void gui(const uint8_t *buf, int skip, int nibbles, double freq)
 					if (pos > nibbles-skip-1)
 						pos = nibbles-skip-1;
 					break;
+				case SDLK_SPACE:
+					if (pos == user_ref)
+						user_ref = -1;
+					else
+						user_ref = pos;
+					break;
 				case SDLK_RETURN:
 				case SDLK_q:
 					return;