Star label missing

[lgarrido]

Hi!

I'm trying to get an A4 chart of Gemini per the included example.

It works fine up to angular_width=22.2. When I push it to 22.3 or beyond, Castor's label disappears.

Fiddling with the center of the chart or font_size may bring it back in some cases, but it's finicky.

Am I missing some configuration tweak?

Regards,

L

# Default settings which affect all the charts below
DEFAULTS
ra_central=7.25
dec_central=20
angular_width=40.0
mag_min=7
width=17.8
aspect=1.36
ra_dec_lines=1
constellation_boundaries=1
constellation_sticks=1
constellation_stick_design=rey
coords=ra_dec
projection=gnomonic
star_names=1
star_flamsteed_labels=0
constellation_names=1
plot_galaxy_map=1
plot_equator=0
plot_ecliptic=0
plot_galactic_plane=1
font_size=1.2
dso_label_mag_min=6

# Produce a PDF copy of this star chart
CHART
output_filename=output/gemini.pdf

[lgarrido]

I have disabled char_check_label_exclusion() and Castor's label comes back, so there must be some object at the exclusion_regions list which somehow conflicts with it. However, I can't see any other label in the map which might clash with Castor's. I'll debug this further when I have some spare time.

[lgarrido]

After some tests I found the problem is star objects of small magnitude create exclusion points (zero-size regions) that supersede labels. Lowering mag_min does away with those stars and brings back the label.

A possible modification to the drawing algorithm would be doing two passes over the labels. A first one would create their exclusion regions, then draw the stars excluding those of small magnitude (mag < star_label_mag_min) that collide with a label, then a second pass over the labels to draw them. I think this would give labels priority over small stars, right?