View Revisions: Issue #2193

Summary 0002193: "Orient to Pole" labels are placed incorrectly.
Revision 19-09-18 17:35 by Patrick Chevalley
Description With "Orient to Pole" checked, the line from the pole to the midpoint of the baseline should be perpendicular to the baseline. Instead, CDC 4.1.1, beta 3899 positions the label so a line from the pole though the left edge of the baseline is perpendicular.

CDC seems to calculate the correct point for the label and the correct text angle for the baseline. But instead of centering the text over the placement point, CDC starts the text at that placement point. You can see the error best with long labels, like Triangulum.

In the provided sample, you can see that the "Triangulum" and "Aries" labels have baselines that are perpendicular to the azimuth grid lines and the text starts at the grid line. Because of that, a line perpendicular to the _center_ of the text baseline won't pass through the pole/zenith. If the text was centered on that calculated label point and at the calculated angle, the label would be properly "oriented to the pole". IOW, the fix seems very simple: Shift the text so it's centered on the placement point.

Revision 19-09-18 00:54 by Joe Shuster
Description With "Orient to Pole" checked, the line from the pole to the midpoint of the baseline should be perpendicular to the baseline. Instead, CDC 4.1.1, beta 3899 positions the label so a line from the pole though the left edge of the baseline is perpendicular.

CDC seems to calculate the correct point for the label and the correct text angle for the baseline. But instead of centering the text over the placement point, CDC starts the text at that placement point. You can see the error best with long labels, like Triangulum.

In the provided sample, you can see that the "Triangulum" and "Aries" labels have baselines that are perpendicular to the azimuth grid lines and the text starts at the grid line. Because of that, a line perpendicular to the _center_ of the text baseline won't pass through the pole/zenith. If the text was centered on that calculated label point and at the calculated angle, the label would be properly "oriented to the pole". IOW, the fix seems very simple: Shift the text so it's centered on the placement point.