font-patcher: Add new option --cell

EXPERIMENTAL

[why]
Sometimes users want to tweak the cell sizing or the baseline to
baseline distance, or the middle point of the cell.

[how]
Add a new option to show the 'cell' box and to override the detected
one. It is not sufficient to adjust width and height, because that can
not define shifts of the cell up/down (left/right is mostly useless and
I believe the code does not work if the xmin is not zero).

The smaller icon-height is not used here (affecting only --mono) because
that seems to compilcated right now.

Signed-off-by: Fini Jastrow <ulf.fini.jastrow@desy.de>

font-patcher

@@ -6,7 +6,7 @@
 from __future__ import absolute_import, print_function, unicode_literals
 
 # Change the script version when you edit this script:
-script_version = "4.17.0"
+script_version = "4.18.0"
 
 version = "3.3.0"
 projectName = "Nerd Fonts"
@@ -1266,6 +1266,14 @@ class font_patcher:
             logger.debug("Metrics is strange")
             pass # Will fail the metrics check some line later
 
+        if self.args.cellopt:
+            logger.debug("Overriding cell Y{%d:%d} with Y{%d:%d}",
+                self.font_dim['ymin'], self.font_dim['ymax'],
+                self.args.cellopt[2], self.args.cellopt[3])
+            self.font_dim['ymin'] = self.args.cellopt[2]
+            self.font_dim['ymax'] = self.args.cellopt[3]
+            our_btb = self.args.cellopt[3] - self.args.cellopt[2]
+
         # Calculate font height
         self.font_dim['height'] = -self.font_dim['ymin'] + self.font_dim['ymax']
         if self.font_dim['height'] == 0:
@@ -1288,7 +1296,7 @@ class font_patcher:
             sys.exit(1)
 
         self.font_dim['iconheight'] = self.font_dim['height']
-        if self.args.single and self.sourceFont.capHeight > 0:
+        if self.args.single and self.sourceFont.capHeight > 0 and not isinstance(self.args.cellopt, list):
             # Limit the icon height on monospaced fonts because very slender and tall icons render
             # excessivly tall otherwise. We ignore that effect for the other variants because it
             # does not look so much out of place there.
@@ -1348,9 +1356,21 @@ class font_patcher:
         if self.font_dim['width'] <= 0:
             logger.critical("Can not detect sane font width")
             sys.exit(1)
+        if isinstance(self.args.cellopt, list):
+            logger.debug("Overriding cell X{%d:%d} with X{%d:%d}",
+                self.font_dim['xmin'], self.font_dim['xmin'] + self.font_dim['width'],
+                self.args.cellopt[0], self.args.cellopt[1])
+            self.font_dim['xmin'] = self.args.cellopt[0]
+            self.font_dim['xmax'] = self.args.cellopt[1]
+            self.font_dim['width'] = self.args.cellopt[1]
         logger.debug("Final font cell dimensions %d w x %d h%s",
             self.font_dim['width'], self.font_dim['height'],
             ' (with icon cell {} h)'.format(int(self.font_dim['iconheight'])) if self.font_dim['iconheight'] != self.font_dim['height'] else '')
+        if self.args.cellopt:
+            logger.info("Cell coordinates %s%d:%d:%d:%d",
+                '' if not isinstance(self.args.cellopt, list) else 'overridden with ',
+                self.font_dim['xmin'], self.font_dim['width'],
+                self.font_dim['ymax'] - self.font_dim['height'], self.font_dim['ymax'])
 
         self.xavgwidth.append(self.args.xavgwidth)
         if isinstance(self.xavgwidth[-1], int) and self.xavgwidth[-1] == 0:
@@ -2030,6 +2050,7 @@ def setup_arguments():
     # <none>  - copy from sourcefont (default)
     # 0       - calculate from font according to OS/2-version-2
     # 500     - set to 500
+    expert_group.add_argument('--cell',                                    dest='cellopt',          default=None,  type=str,            help='Adjust or quiery the call size, e.g. use "0:1000:-200:800" resp "?"')
 
     # progress bar arguments - https://stackoverflow.com/questions/15008758/parsing-boolean-values-with-argparse
     progressbars_group_parser.add_argument('--progressbars',         dest='progressbars',     action='store_true',                help='Show percentage completion progress bars per Glyph Set (default)')
@@ -2096,6 +2117,23 @@ def setup_arguments():
         logger.warning("Specified contradicting --variable-width-glyphs together with --mono or --single-width-glyphs. Ignoring --variable-width-glyphs.")
         args.nonmono = False
 
+    if args.cellopt:
+        if args.cellopt != '?':
+            try:
+                parts = [ int(v) for v in args.cellopt.split(':') ]
+                if len(parts) != 4:
+                    raise
+            except:
+                logger.critical("Parameter for --cell is not 4 colon seprated integer numbers: '%s'", args.cellopt)
+                sys.exit(2)
+            if parts[0] >= parts[1] or parts[2] >= parts[3]:
+                logger.critical("Parameter for --cell do not result in positive cell size: %d x %d",
+                    parts[1] - parts[0], parts[3] - parts[2])
+                sys.exit(2)
+            if parts[0] != 0:
+                logger.warn("First parameter for --cell should be zero, this is probably not working")
+            args.cellopt = parts
+
     make_sure_path_exists(args.outputdir)
     if not os.path.isfile(args.font):
         logger.critical("Font file does not exist: %s", args.font)