[core] Added mbgl::util::DEFAULT_TRANSITION_EASE

include/mbgl/util/constants.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/util/chrono.hpp>
+#include <mbgl/util/unitbezier.hpp>
 
 #include <cmath>
 #include <string>
@@ -40,6 +41,8 @@ constexpr uint64_t DEFAULT_MAX_CACHE_SIZE = 50 * 1024 * 1024;
 constexpr Duration DEFAULT_FADE_DURATION = Milliseconds(300);
 constexpr Seconds CLOCK_SKEW_RETRY_TIMEOUT { 30 };
 
+constexpr UnitBezier DEFAULT_TRANSITION_EASE = { 0, 0, 0.25, 1 };
+
 } // namespace util
 
 namespace debug {

src/mbgl/map/transform.cpp

@@ -584,7 +584,7 @@ void Transform::startTransition(const CameraOptions& camera,
         if (t >= 1.0) {
             result = frame(1.0);
         } else {
-            util::UnitBezier ease = animation.easing ? *animation.easing : util::UnitBezier(0, 0, 0.25, 1);
+            util::UnitBezier ease = animation.easing ? *animation.easing : util::DEFAULT_TRANSITION_EASE;
             result = frame(ease.solve(t, 0.001));
         }