A new script to merge metrics and kerning data from an existing font.

README.md

@@ -18,26 +18,13 @@ Process
 
 #### Get a bitmap image of characters (crop unnecessary white parts for a faster process, you can use Gimp's automatic crop for that).
 
-![](
-
-
-
-
-
-
-
-
-
-
-http://osp.kitchen/api/osp.tools.fons/raw/input/scan_bitmap.jpg)
+![](http://osp.kitchen/api/osp.tools.fons/raw/input/scan_bitmap.jpg)
 :    A scan in bitmap
 
-![](
-http://osp.kitchen/api/osp.tools.fons/raw/input/scan_gray_1200dpi.jpg)
+![](http://osp.kitchen/api/osp.tools.fons/raw/input/scan_gray_1200dpi.jpg)
 :    A scan in gray levels
 
-![](
-http://osp.kitchen/api/osp.tools.fons/raw/input/rasterized_ospDIN.png)
+![](http://osp.kitchen/api/osp.tools.fons/raw/input/rasterized_ospDIN.png)
 :    A rasterized font
 
 
@@ -46,8 +33,7 @@ http://osp.kitchen/api/osp.tools.fons/raw/input/rasterized_ospDIN.png)
 
 #### Levels (have a white background, black characters but still shades of gray)
 
-![](
-http://osp.kitchen/api/osp.tools.fons/raw/documentation/01-bitmap_levels.png)
+![](http://osp.kitchen/api/osp.tools.fons/raw/documentation/01-bitmap_levels.png)
 
 
 
@@ -55,8 +41,7 @@ http://osp.kitchen/api/osp.tools.fons/raw/documentation/01-bitmap_levels.png)
 
 Scale up the image to something like 254% with the "Sinc (Lanczos 3)" algorithm. We choose on purpose a non-round number of scaling to break the bitmap patterns.
 
-![](
-http://osp.kitchen/api/osp.tools.fons/raw/documentation/02-scale-254percent.png)
+![](http://osp.kitchen/api/osp.tools.fons/raw/documentation/02-scale-254percent.png)
 
 
 
@@ -64,15 +49,12 @@ http://osp.kitchen/api/osp.tools.fons/raw/documentation/02-scale-254percent.png)
 
 Put the amount to the maximum and then search for the point where you don't see 
 
-![bad](
-http://osp.kitchen/api/osp.tools.fons/raw/documentation/03-sharpen-too_few.png)
+![bad](http://osp.kitchen/api/osp.tools.fons/raw/documentation/03-sharpen-too_few.png)
 :    Radius too small
 
-![ok](
-http://osp.kitchen/api/osp.tools.fons/raw/documentation/03-sharpen-ok.png)
+![ok](http://osp.kitchen/api/osp.tools.fons/raw/documentation/03-sharpen-ok.png)
 
-![bad](
-http://osp.kitchen/api/osp.tools.fons/raw/documentation/03-sharpen-too_much.png)
+![bad](http://osp.kitchen/api/osp.tools.fons/raw/documentation/03-sharpen-too_much.png)
 
 
 
@@ -80,20 +62,17 @@ http://osp.kitchen/api/osp.tools.fons/raw/documentation/03-sharpen-too_much.png)
 
 Scale up to 403% (check on notebook or with PierreH if it's enough)
 
-![](
-http://osp.kitchen/api/osp.tools.fons/raw/documentation/04-big_boost.png)
+![](http://osp.kitchen/api/osp.tools.fons/raw/documentation/04-big_boost.png)
 
 
 
 #### Threshold
 
 
-![bad](
-http://osp.kitchen/api/osp.tools.fons/raw/documentation/05-threshold-bad.png)
+![bad](http://osp.kitchen/api/osp.tools.fons/raw/documentation/05-threshold-bad.png)
 
 
-![ok](
-http://osp.kitchen/api/osp.tools.fons/raw/documentation/05-threshold-ok.png)
+![ok](http://osp.kitchen/api/osp.tools.fons/raw/documentation/05-threshold-ok.png)
 
 
 Save as a .bmp file.
@@ -110,13 +89,28 @@ Save as a .bmp file.
 IMPORTANT: If you zoom out to select the letters, don't forget to go back to zoom 1 before generating the font file. Don't close GlyphTracer before checking the .sfd file, then you can export again if you forgot to zoom back in.
 
 
+### Merging fonts
+
+In case you want to complete an existing font, you can use the script `mergeFonts.py`.
+
+    python mergeFonts.py fonte1.ufo fonte2.ufo ...  fonte17.ufo fonte-out.ufo
+
+
+### Metrics and kernings
+
+A big part of type design is about managing the white space around the letters (metrics) and exceptions for specific couples of letters (kernings).
+
+- For the metrics, we make an auto-spacing while generating the .sfd file with GlyphTracer.
+- For the kernings, you can try the tool (Kernagic)[https://github.com/hodefoting/kernagic].
 
+But if you want to get back metric and kerning data from an existing font, you can use the script `mergeSpacing.py`. It can be any font format than `.otf`.
 
+   python mergeSpacing.py font.otf original-font.otf spaced-font.otf
 
 
 
 Troubleshooting
-----------------------
+---------------
 
 ### My image is too big to manipulate it.
 Split it into several images and generate several .sfd files. Then you can merge the fonts with the script `mergeFonts.py`.

mergeSpacing.py

+#! /usr/bin/python
+
+"""
+Merges the spacing information from one base font to your font and produces a new font (keeping the original fonts intact).
+It can take any font format that Fontforge can open: .ufo, .otf, .sfd...
+
+Usage:
+    python mergeSpacing.py MyFont.ufo BaseFont.ufo SpacedFont.ufo
+"""
+
+
+import fontforge
+import sys
+
+
+font = fontforge.open(sys.argv[1])
+original = fontforge.open(sys.argv[2])
+
+
+# MERGE SPACINGS
+for g in font.glyphs():
+    char = g.glyphname
+    # Gets original font bearings
+    left = original[char].left_side_bearing
+    right = original[char].right_side_bearing
+
+    # Sets current bearings to 0
+    font[char].left_side_bearing = 0
+    font[char].right_side_bearing = 0
+
+    # Gets drawing width
+    width = font[char].width
+
+    # Resize the width with original bearings
+    font[char].width = left + width + right
+    font[char].left_side_bearing = left
+    font[char].right_side_bearing = right
+
+
+# EXPORT ORIGINAL FONT AS PFA/AFM TO GET OPENTYPE FEATURES FROM AN AFM FILE
+afm = original.generate("%s.pfa" % sys.argv[2])
+
+# MERGE OPENTYPE FEATURES (including kernings)
+font.mergeFeature("%s.afm" % sys.argv[2])
+#font.mergeLookups(original)
+#font.mergeLookupSubtables(original)
+
+ 
+font.generate(sys.argv[3])