From af2e05cbdfcb0574d20d9c53663ae03819a10fcb Mon Sep 17 00:00:00 2001
From: Pascal Massimino <pascal.massimino@gmail.com>
Date: Wed, 24 Aug 2016 11:04:17 +0200
Subject: [PATCH] vwebp: Clear previous frame when a key triggers a redraw

otherwise, transparent areas were accumulating.

Change-Id: I066a96a2bcf0cac750b3df0c02229542b1ed3473
(cherry picked from commit c0a27fd2af75dc0c6df7e0847a45fa152b45d0ab)
---
 examples/vwebp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/examples/vwebp.c b/examples/vwebp.c
index 4b3fcf62..61e534ed 100644
--- a/examples/vwebp.c
+++ b/examples/vwebp.c
@@ -242,6 +242,9 @@ static void HandleKey(unsigned char key, int pos_x, int pos_y) {
     }
   } else if (key == 'i') {
     kParams.print_info = 1 - kParams.print_info;
+    // TODO(skal): handle refresh of animation's last-frame too. It's quite
+    // more involved though (need to save the previous frame).
+    if (!kParams.has_animation) ClearPreviousFrame();
     glutPostRedisplay();
   }
 }