From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 2 Jul 2018 11:43:02 +0000 (+0300)
Subject: Require the first keyframe of an animation to be at zero offset
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=8d8b80f3c1511b37f030d897ad97b92993a03ca2;p=libs%2Fgl.git

Require the first keyframe of an animation to be at zero offset

Having empty space at the start of an animation produces unexpected
results.
---

diff --git a/source/animation.cpp b/source/animation.cpp
index b58a4ea7..02a2d371 100644
--- a/source/animation.cpp
+++ b/source/animation.cpp
@@ -61,6 +61,8 @@ void Animation::add_keyframe(const Time::TimeDelta &t, const KeyFrame &kf, float
 
 void Animation::add_keyframe(const Time::TimeDelta &t, const RefPtr<const KeyFrame> &kf, float ss, float es)
 {
+	if(keyframes.empty() && t!=Time::zero)
+		throw invalid_argument("Animation::add_keyframe");
 	if(!keyframes.empty() && t<keyframes.back().time)
 		throw invalid_argument("Animation::add_keyframe");