Figure.pygmtlogo: Improved positioning of horizontal wordmark for circular PyGMT logo (#4627)

Author: seisman

pygmt/src/pygmtlogo.py

@@ -34,7 +34,7 @@ def _create_logo(  # noqa: PLR0915
     size = 4
     proj = "x1c"
     region = {
-        "horizontal": [-size, size * 8.0, -size, size],
+        "horizontal": [-size, size * 7.0, -size, size],
         "vertical": [-size, size, -size * 1.75, size],
         "none": [-size, size, -size, size],
     }[wordmark]
@@ -79,12 +79,27 @@ def _create_logo(  # noqa: PLR0915
             hex_factor = 1.1
 
     # Define wordmark
+    # See https://github.com/GenericMappingTools/pygmt/pull/4627#issuecomment-4437317011
+    # for the rationale behind the magic values.
     font = "AvantGarde-Book"
+    pheight = 0.739  # Height of letter "P"
+    plsb = 0.076  # Left side bearing of letter "P"
+    pstroke = 0.0735  # Stroke thickness of letter "P"
+
     match wordmark:
         case "vertical":
-            args_text_wm = {"x": 0, "y": -4.5, "justify": "CT", "font": f"2.4c,{font}"}
+            args_wordmark = {"x": 0, "y": -4.5, "justify": "CT", "font": f"2.4c,{font}"}
         case "horizontal":
-            args_text_wm = {"x": 4.5, "y": 0.8, "justify": "LM", "font": f"8c,{font}"}
+            # The stroke width matches the outline thickness.
+            # The left edge of "P" is aligned at y=size * 1.25.
+            # Letters "PGMT" are placed vertically centered at y=0.
+            fontsize = thick_shape / pstroke
+            args_wordmark = {
+                "x": size * 1.25 - plsb * fontsize,
+                "y": -pheight / 2.0 * fontsize,
+                "justify": "BL",
+                "font": f"{fontsize}c,{font}",
+            }
 
     def _letter_g_coords():
         """Coordinates for letter G."""
@@ -218,7 +233,7 @@ def _compass_lines():
 
     # Add wordmark "PyGMT"
     if wordmark != "none":
-        fig.text(text=f"@;{color_py};Py@;;@;{color_gmt};GMT@;;", **args_text_wm)
+        fig.text(text=f"@;{color_py};Py@;;@;{color_gmt};GMT@;;", **args_wordmark)
 
     # Helpful for implementing the logo; not included in the logo
     if debug:
@@ -237,6 +252,11 @@ def _compass_lines():
         fig.hlines(y=[r4, r5], xmin=-size_s, xmax=size_s, pen=pen, perspective=True)
         m_mid = (thick_gap + r4) / 2
         fig.vlines(x=[r4, m_mid], ymin=-size_s, ymax=size_s, pen=pen, perspective=True)
+        # Lines for wordmark
+        if wordmark == "horizontal":
+            halfheight = pheight / 2.0 * fontsize
+            fig.hlines(y=[-halfheight, halfheight], xmin=size, pen=pen)
+            fig.vlines(x=[size * 1.25, size * 1.25 + pstroke * fontsize], pen=pen)
 
     if figname:
         fig.savefig(fname=figname)

pygmt/tests/baseline/test_pygmtlogo_design_circle-horizontal.png.dvc

@@ -1,5 +1,5 @@
 outs:
-- md5: 8924c7d80afcc92df4e77e6856b553a4
-  size: 336254
+- md5: 44a9a200fbac4c868b69cb1c13e6dfc5
+  size: 320394
   hash: md5
   path: test_pygmtlogo_design_circle-horizontal.png

pygmt/tests/baseline/test_pygmtlogo_wordmark_horizontal_circle.png.dvc

@@ -0,0 +1,5 @@
+outs:
+- md5: 9715eb13bec45201818d701970a529c8
+  size: 63949
+  hash: md5
+  path: test_pygmtlogo_wordmark_horizontal_circle.png

pygmt/tests/test_pygmtlogo.py

@@ -49,3 +49,32 @@ def test_pygmtlogo_wordmark_none(shape):
             shape=shape,
         )
     return fig
+
+
+@pytest.mark.mpl_image_compare
+@pytest.mark.parametrize("shape", ["circle"])
+def test_pygmtlogo_wordmark_horizontal(shape):
+    """
+    Test the PyGMT logo with a horizontal wordmark, including both light/dark themes,
+    and colored/black-and-white versions.
+    """
+    fig = Figure()
+    fig.basemap(
+        region=[-0.5, 8.0, -0.5, 10.0],
+        projection="x1c",
+        frame=Frame(fill="gray", axis=Axis(grid=0.5)),
+    )
+    for (x, y), theme, color in [
+        ((0, 8.5), "light", True),
+        ((0, 6), "dark", True),
+        ((0, 3.5), "light", False),
+        ((0, 1), "dark", False),
+    ]:
+        fig.pygmtlogo(
+            position=Position((x, y), anchor="ML", cstype="mapcoords"),
+            theme=theme,
+            color=color,
+            shape=shape,
+            wordmark="horizontal",
+        )
+    return fig