Figure.pygmtlogo: Improve positioning of vertical wordmark for circular PyGMT logo

[seisman]

This is a follow-up PR to #4627. See PR #4627 for additional context.

The script demonstrates two different approaches for centering the wordmark beneath the visual logo. Version 1 is simpler, but the centering is only approximate. Version 2 uses the font metrics to achieve exact centering.

import pygmt
from pygmt.params import Position

pheight = 0.739  # Height of "P"
plsb = 0.076 # Left side bearing of "P"
pstroke = 0.0735  # Stroke thickness of "P"
ydesc = 0.192  # Descender depth of "y"
pygmtwidth = 3.262   # Full width of "PyGMT"

fontsize = 8 / pygmtwidth
# fontsize = 2.2
# Version 1: Center using "TC"
x0, y0, justify = 0, -4.5, "TC"
# Version 2: Accurate centering
x0, y0, justify = -4 - fontsize * plsb, -4.5, "TL"

fig = pygmt.Figure()
fig.basemap(region=[-4, 4, -7, 4], projection="x1c", frame="ag1")
fig.pygmtlogo(width="8c", position=Position((0, 0), cstype="mapcoords", anchor="MC"))
fig.text(x=x0, y=y0, justify=justify, text="PyGMT", font=f"{fontsize}c,AvantGarde-Book", no_clip=True)
fig.hlines(y=-4.5, pen="1p,gray,-")
fig.show()
fig.savefig("logo-wordmark.png")

Version 1	Version 2

Additional notes for Version 2:

• The top of the letter G aligns at y=-4.5, rather than the tops of the letters PMT

• Alternatively, it would also be possible to:

  • align the tops of the letters PMT at y=-4.5, or
  • vertically center the letters PMT at y=-5.5

We may also want to ensure it also works well with hexagon shape, but it's always easier to decide an initial version for circular logo first, then revise it later when working on hexagon logos.

[github-actions]

Summary of changed images

This is an auto-generated report of images that have changed on the DVC remote

Status	Path
added	pygmt/tests/baseline/test_pygmtlogo_wordmark_vertical_circle.png
modified	pygmt/tests/baseline/test_pygmtlogo_design_circle-vertical.png

Image diff(s)

Details

Added images

• test_pygmtlogo_wordmark_vertical_circle.png

Modified images

Path	Old	New
test_pygmtlogo_design_circle-vertical.png

Report last updated at commit 8b7b3bb

[yvonnefroehlich]

I prefer the exact centering via version 2, with a vertical centering of "PMT" at y=-5.5.

[seisman]

I prefer the exact centering via version 2, with a vertical centering of "PMT" at y=-5.5.

Done in 4efe98f