Handle really long map names by wrapping them.

This is set to 75% of the image width by default and is (not yet)
configurable.

dcc/text.py

@@ -1,11 +1,13 @@
 import dcc.config
 import dcc.doom_base
 import sys
+import textwrap
 import wand.drawing
 import wand.image
 
 
-def draw_text(self, img, text, font_size=64):
+def draw_text(self, img, text, font_size=64, wrap_dist=0.75):
+    textlines = text.splitlines()
     with wand.drawing.Drawing() as draw:
         draw.font = self.thumbnail_font
         draw.font_size = font_size
@@ -13,11 +15,41 @@ def draw_text(self, img, text, font_size=64):
         draw.stroke_color = wand.color.Color(self.thumbnail_text_stroke)
         draw.stroke_width = font_size * 5 / 32
         draw.text_interline_spacing = -font_size / 4
-        draw.text(5, int(draw.font_size) + 5, text)
+
+        target_width = wrap_dist * img.width
+
+        def eval_metrics(txt):
+            metrics = draw.get_font_metrics(img, wrapped_text, True)
+            return (metrics.text_width, metrics.text_height)
+
+        for idx, wrapped_text in enumerate(textlines):
+            while True:
+                width, height = eval_metrics(wrapped_text)
+                if width <= target_width:
+                    break
+                columns = len(wrapped_text)
+                while columns > 0:
+                    columns -= 1
+                    wrapped_text = '\n'.join(
+                        textwrap.wrap(wrapped_text, columns)
+                    )
+                    wrapped_width, _ = eval_metrics(wrapped_text)
+                    if wrapped_width <= target_width:
+                        break
+                if columns == 0:
+                    raise Exception(
+                        "couldn't calculate text wrapping; "
+                        + f"final attempt was {wrapped_text}"
+                    )
+            textlines[idx] = wrapped_text
+
+        wrapped_text = '\n'.join(textlines)
+
+        draw.text(5, int(draw.font_size) + 5, wrapped_text)
         draw(img)
         draw.stroke_color = wand.color.Color("none")
         draw.stroke_width = 0
-        draw.text(5, int(draw.font_size)+5, text)
+        draw.text(5, int(draw.font_size)+5, wrapped_text)
         draw(img)