Clear the ts event buffer at appropriate points in ts_calibrate

Fixes the issue where an accidental double-tap at one coordinate results in
having to restart the calibration, since the second tap gets read as the next
coordinate for the calibration.  Patch courtesy MontaVista Software, Inc.

Signed-off-by: Chris Larson <clarson@kergoth.com>

diff --git a/tests/ts_calibrate.c b/tests/ts_calibrate.c
index 004517b..03c58fb 100644 (file)
--- a/tests/ts_calibrate.c
+++ b/tests/ts_calibrate.c
@@ -162,6 +162,31 @@ static void get_sample (struct tsdev *ts, calibration *cal,
        printf("%s : X = %4d Y = %4d\n", name, cal->x [index], cal->y [index]);
 }
 
+static int clearbuf(struct tsdev *ts)
+{
+       int fd = ts_fd(ts);
+       fd_set fdset;
+       struct timeval tv;
+       int nfds;
+       struct ts_sample sample;
+
+       while (1) {
+               FD_ZERO(&fdset);
+               FD_SET(fd, &fdset);
+
+               tv.tv_sec = 0;
+               tv.tv_usec = 0;
+
+               nfds = select(fd + 1, &fdset, NULL, NULL, &tv);
+               if (nfds == 0) break;
+
+               if (ts_read_raw(ts, &sample, 1) < 0) {
+                       perror("ts_read");
+                       exit(1);
+               }
+       }
+}
+
 int main()
 {
        struct tsdev *ts;
@@ -210,13 +235,17 @@ int main()
 
        printf("xres = %d, yres = %d\n", xres, yres);
 
-// Read a touchscreen event to clear the buffer
-       //getxy(ts, 0, 0);
+       // Clear the buffer
+       clearbuf(ts);
 
        get_sample (ts, &cal, 0, 50,        50,        "Top left");
+       clearbuf(ts);
        get_sample (ts, &cal, 1, xres - 50, 50,        "Top right");
+       clearbuf(ts);
        get_sample (ts, &cal, 2, xres - 50, yres - 50, "Bot right");
+       clearbuf(ts);
        get_sample (ts, &cal, 3, 50,        yres - 50, "Bot left");
+       clearbuf(ts);
        get_sample (ts, &cal, 4, xres / 2,  yres / 2,  "Center");
 
        if (perform_calibration (&cal)) {