From 78ad57a36ad69a9c22874b182d49d64125c380f2 Mon Sep 17 00:00:00 2001
From: Yannis Guyon <yguyon@google.com>
Date: Wed, 18 Jul 2018 10:36:19 +0200
Subject: [PATCH] Fix bad glClearColor parameters

Container spec indicates that background color is written
in BGRA byte order, but glClearColor() parameters are RGBA.
Anyway the checkerboard is displayed right after glClear()
calls so it replaces background color.

In response to webp-discuss/TkLHALGaHaM

Change-Id: Ief5435fadfd6a422b881a9dc240b5e8dc6546e19
---
 examples/vwebp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/vwebp.c b/examples/vwebp.c
index f3f16474..80d930c3 100644
--- a/examples/vwebp.c
+++ b/examples/vwebp.c
@@ -408,9 +408,9 @@ static void StartDisplay(void) {
   glutKeyboardFunc(HandleKey);
   glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
   glEnable(GL_BLEND);
-  glClearColor(GetColorf(kParams.bg_color, 0),
+  glClearColor(GetColorf(kParams.bg_color, 16),  // BGRA from spec
                GetColorf(kParams.bg_color, 8),
-               GetColorf(kParams.bg_color, 16),
+               GetColorf(kParams.bg_color, 0),
                GetColorf(kParams.bg_color, 24));
   glClear(GL_COLOR_BUFFER_BIT);
   DrawCheckerBoard();