selfImDrawList handle on which this method operates.
centerShape center in absolute screen coordinates.
radiusHorizontal and vertical ellipse radii in pixels, before rotation.
colPacked ImU32 RGBA color; alpha controls opacity.
rotEllipse rotation angle in radians.
num_segmentsCurve tessellation segment count; 0 lets ImGui choose automatically.
thicknessStroke thickness in screen pixels.
Append the outline of an ellipse to the draw list.