From ba8eadee2f8285db29140e72cc1f28559b474868 Mon Sep 17 00:00:00 2001
From: Wolfgang Hoenig <hoenig@tu-berlin.de>
Date: Thu, 5 Jan 2023 16:02:49 +0100
Subject: [PATCH] USD deck: parser and plotter improvements

* config.txt parser: allow empty lines and lines with just comments
* plot_events.py: fix error when only one event type is recorded
---
 src/deck/drivers/src/usddeck.c | 12 +++++++++---
 tools/usdlog/plot_events.py    |  8 ++++----
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/deck/drivers/src/usddeck.c b/src/deck/drivers/src/usddeck.c
index 35506e3071..c49081b54a 100644
--- a/src/deck/drivers/src/usddeck.c
+++ b/src/deck/drivers/src/usddeck.c
@@ -416,7 +416,8 @@ TCHAR* f_gets_without_comments (
   while (n < len - 1) { /* Read characters until buffer gets filled */
     f_read(fp, &c, 1, &rc);
     if (rc != 1) {
-      break;
+      *p = 0;
+      return 0; /* When no data read (eof or error), return with error. */
     }
     if (c == '\n') {
       if (isPureComment){
@@ -441,7 +442,7 @@ TCHAR* f_gets_without_comments (
     }
   }
   *p = 0;
-  return n ? buff : 0;      /* When no data read (eof or error), return with error. */
+  return buff;
 }
 
 
@@ -636,8 +637,13 @@ static void usdLogTask(void* prm)
           cfg->numBytes = 0;
           while (true) {
             line = f_gets_without_comments(readBuffer, sizeof(readBuffer), &logFile);
-            if (!line || strncmp(line, "on:", 3) == 0)
+            if (!line || strncmp(line, "on:", 3) == 0) {
               break;
+            }
+            // skip lines that do not have at least two characters (1 for group, 1 for '.', 1 for name)
+            if (strlen(line) <= 3) {
+              continue;
+            }
             char *group = line;
             char *name = 0;
             for (int i = 0; i < strlen(line); ++i) {
diff --git a/tools/usdlog/plot_events.py b/tools/usdlog/plot_events.py
index d707d5d8e3..889ba838da 100644
--- a/tools/usdlog/plot_events.py
+++ b/tools/usdlog/plot_events.py
@@ -31,13 +31,13 @@ def showAnnotation(data, sel):
             start_time = min(start_time, data['timestamp'][0])
 
     # new figure
-    fig, ax = plt.subplots(len(data_usd.keys()),1,sharex=True)
+    fig, ax = plt.subplots(len(data_usd.keys()),1,sharex=True,squeeze=False)
 
     for k, (event_name, data) in enumerate(data_usd.items()):
         # print(k, event_name)
         t = (data['timestamp'] - start_time) / 1000
-        ax[k].scatter(t, t*0)
-        ax[k].set_title(event_name)
+        ax[k,0].scatter(t, t*0)
+        ax[k,0].set_title(event_name)
 
         print(data.keys())
 
@@ -45,7 +45,7 @@ def showAnnotation(data, sel):
 
         crs.connect("add", functools.partial(showAnnotation, data))
 
-    ax[-1].set_xlabel('Time [s]')
+    ax[-1,0].set_xlabel('Time [s]')
 
 
     plt.show()