Add (early) notes about font format

extras/notes.txt

@@ -0,0 +1,31 @@
+otf2bdf - converts truetype to BDF font format
+
+https://www.math.nmsu.edu/~mleisher/Software/otf2bdf/
+
+sudo apt-get install otf2bdf
+
+
+
+
+Per-font encoding:
+
+#bits for horiz advance
+#bits for width
+#bits for height
+#bits for x offset
+#bits for y offset
+#bits in offsets table
+table of offset for all chars
+
+Per-char encoding:
+
+WIDTH
+BBX: width, height
+BBX: x offset, y offset
+pixel data, bit packed:
+if 1st bit = 0, rest is bits for 1 line
+if 1st bit = 1, next 3 bits are #repeat (0 to 5), followed by 1 line
+
+
+
+