ios - Mimic Apple's UIViewAnimationOptionCurveEaseInOut math equation? -

i want create animation appear animate apple's curveeaseinout, application looks consistent. problem particular animation cannot use uiview animate method. must manipulate position manually @ every frame. example, time t , need output center c point @ time. rather using linear relationship (e.g. c = t), want ease in , out apple does.

which curve equation apple using animation option?

i assume curve looks similar this: (which taken this question)

if case, looks should able tweak cubic hermite spline equation correct constants , same result. question constants apple use?

as carbonic acid (h2co3) pointed out, question control points apple use.

assuming it's same default timing function in core animation control points documentation:

kcamediatimingfunctiondefault specifies timing function used default animations. approximates bézier timing function using control points [(0.0,0.0), (0.25,0.1), (0.25,0.1), (1.0,1.0)]. using constant ensure animations use current default timing.

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edit

since mention custom animation recommend watch animation custom layer properties presentation rob napier. benefit core animation while still doing custom animation. (watch entire presentation. helps understanding of core animation)