fix animation reversing by removing undocumented and buggy "reverse_a…

…djustment_factor"

Include/RmlUi/Core/Animation.h

@@ -51,7 +51,6 @@ struct Transition {
 	Tween tween;
 	float duration = 0.0f;
 	float delay = 0.0f;
-	float reverse_adjustment_factor = 0.0f;
 };
 
 struct TransitionList {
@@ -74,8 +73,7 @@ inline bool operator!=(const Animation& a, const Animation& b)
 }
 inline bool operator==(const Transition& a, const Transition& b)
 {
-	return a.id == b.id && a.tween == b.tween && a.duration == b.duration && a.delay == b.delay &&
-		a.reverse_adjustment_factor == b.reverse_adjustment_factor;
+	return a.id == b.id && a.tween == b.tween && a.duration == b.duration && a.delay == b.delay;
 }
 inline bool operator!=(const Transition& a, const Transition& b)
 {

Source/Core/Element.cpp

@@ -2534,9 +2534,7 @@ bool Element::StartTransition(const Transition& transition, const Property& star
 	else
 	{
 		// Compress the duration based on the progress of the current animation
-		float f = it->GetInterpolationFactor();
-		f = 1.0f - (1.0f - f) * transition.reverse_adjustment_factor;
-		duration = duration * f;
+		duration *= it->GetInterpolationFactor();
 		// Replace old transition
 		*it = ElementAnimation{transition.id, ElementAnimationOrigin::Transition, start_value, *this, start_time, 0.0f, 1, false};
 	}

Source/Core/PropertyParserAnimation.cpp

@@ -279,17 +279,6 @@ static bool ParseTransition(Property& property, const StringList& transition_val
 						else
 							return false;
 					}
-					else
-					{
-						// No 's' unit means reverse adjustment factor was found
-						if (!reverse_adjustment_factor_found)
-						{
-							reverse_adjustment_factor_found = true;
-							transition.reverse_adjustment_factor = number;
-						}
-						else
-							return false;
-					}
 				}
 				else
 				{
@@ -317,8 +306,6 @@ static bool ParseTransition(Property& property, const StringList& transition_val
 		if ((transition_list.all && !target_property_ids.Empty())    //
 			|| (!transition_list.all && target_property_ids.Empty()) //
 			|| transition.duration <= 0.0f                           //
-			|| transition.reverse_adjustment_factor < 0.0f           //
-			|| transition.reverse_adjustment_factor > 1.0f           //
 		)
 		{
 			return false;

Source/Core/TypeConverter.cpp

@@ -123,8 +123,6 @@ bool TypeConverter<TransitionList, String>::Convert(const TransitionList& src, S
 			dest += tmp + "s ";
 		if (t.delay > 0.0f && TypeConverter<float, String>::Convert(t.delay, tmp))
 			dest += tmp + "s ";
-		if (t.reverse_adjustment_factor > 0.0f && TypeConverter<float, String>::Convert(t.reverse_adjustment_factor, tmp))
-			dest += tmp + ' ';
 		if (dest.size() > 0)
 			dest.resize(dest.size() - 1);
 		if (i != src.transitions.size() - 1)