1 files changed, 3 insertions, 1 deletions
diff --git a/progs/trivial/tri-viewport.c b/progs/trivial/tri-viewport.c
index c08089b9dd..37e424467b 100644
--- a/progs/trivial/tri-viewport.c
+++ b/progs/trivial/tri-viewport.c
@@ -72,7 +72,9 @@ static void Key(unsigned char key, int x, int y)
    case 'H':
       th -= 1.0;
       break;
-
+   case ' ':
+      tw = th = tx = ty = 0;
+      break;
    default:
       break;
    }