Speed, time and waylength have to fit. Verify your speed/way/duration with v_ges=s/t
Remember that v_ges = sqrt(v_x^2 +v_y^2) as it is a vector ((here v_ges,1 = v_x,1,-v_y,1))

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Define the vector of your current point so that the tangent will fit with the vector/tangent from the previous point
Be aware that the shape of the curve is not only affected by the vector of the starting point but also of the vector at the end point/next starting point
use always a speed for both dimensions (even it is only a very small value) to ensure the right tilt of your curve. → Draw your shape first and define the signs of your vectors. It turned out to be the easiest way to ensure the right orientations.
Remember that your are giving a trajectory to a physical system so sharp edges won't be possible

C++

MATLAB

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