markummitchell / engauge-digitizer

Extracts data points from images of graphs
GNU General Public License v2.0
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Circle Centerpoint Offcenter on Small Circles #434

Open NZarilla opened 1 year ago

NZarilla commented 1 year ago

Hello,

If you begin a curve on a plot with a circle set to a small size (most notable at 2-4 size), the centerpoints for those citcles will actually be off-center from the center of the circle shape itself. This issue maintains regardless of zoom level or later adjustment of circle size. Note that the line intersection point is placed correctly at the cursor position - it is the circle shape itself that is off-center from this point.

This notably does not happen if the curve is begun when the circle is of a larger size (tested at 10-20), even if the circle is shrunk to a small size (2-4) after curve initialization.

Attached find four files showing the results of initialization at size 11 with a resize to size 2, and an initialization at size 2 with a resize to size 11. The misalignment is clear in the latter two.

Size 11 Initialization: 11-Size-Initialization

Size 11 Init/Size 2 Resize: 11-Size-Initialization-2-Resize

Size 2 Initialization: 2-Size-Initialization

Size 2 Init/Size 11 Resize: 2-Size-Initialization-11-Resize