2022 / Day 10: BAD
My knowledge of colors and colorspaces is really minimal (if not to say missing completely) so very often you’ll find me using very high-contrast colors to differentiate stuff that has been queried from other stuff that had been queried before. Anyway. Color gradients are not “linear”, but this time around - who cares!
So the query today will generate_series of color hex values between #BAD
and #A55 by a step of #001 in integers and convert those to hex again to
apply them on a set of concentric point buffers (increasing in size). In order
to make it more spaced out, man!!! every disk will have a 01 opacity set
to it so we’ll end up with hex code of
#RRGGBBAA
which can be very easily used in QGIS for styling every specific feature.
with
minmax as (
select
1 as oid,
st_point(
40500.000000,5993000.000000,3301
) as ll,
st_point(
1064500.000000,7017000.000000,3301
) as ur
),
c as (
select
st_centroid(
st_collect(
array[ll,ur]
)
) as geom
from
minmax
),
mm as (
select
('x'||'BAD')::bit(24)::int as min,
('x'||'A55')::bit(24)::int as max,
('x'||'001')::bit(24)::int as step
)
select
color.radius as oid,
st_buffer(c.geom, color.radius*10, 'quad_segs=16') as geom,
'#'||a[1]||a[1]||a[2]||a[2]||a[3]||a[3]||'01' as hex
from
c, (
select
row_number() over ()::int as radius,
to_hex(s) as hex
from
mm
join lateral
generate_series(
mm.min,
mm.max,
-1*mm.step
) s on true
) color
join lateral
regexp_split_to_array(
color.hex,
''
) a on true
order by
color.radius desc
;