font and reverse added

font/README.md

@@ -28,3 +28,16 @@ copied to the scripts directory and used to build firmware with the file as a fr
 
 This assumes Linux but CfontToBinary.py is plain Python3 and should run on other platforms. 
 
+# The font matrix
+
+In the C file each character is stored as a fixed size array of bytes, the first byte being
+the character width. When rendering a font to a device, fonts designed as variable pitch
+should use this byte as the width. Monospaced fonts should be rendered using the font's
+width (see pyfont.py).
+
+# Note
+
+If anyone knows a Python way of converting a font file (a.g. ttf) to a bitmap, please let me
+know. My own efforts were not good enough hence my reluctant advocacy of the above closed source
+program.
+

font/pyfont.py

@@ -0,0 +1,34 @@
+
+class PyFont(object):
+    def __init__(self, font, vert, horiz, nchars):
+        self.bits_horiz = horiz
+        self.bits_vert = vert
+        div, mod = divmod(self.bits_vert, 8)
+        self.bytes_vert = div if mod == 0 else div +1
+        self.bytes_per_ch = self.bytes_vert * self.bits_horiz +1
+        self.nchars = nchars
+        self.font = font
+        self.monospaced = False
+
+    def render(self, ch): # enter with ord(ch)
+        relch = ch -32
+        if relch > self.nchars:
+            raise ValueError('Illegal character')
+        offset = relch * self.bytes_per_ch
+        bv = self.bits_vert
+        bh = self.bits_horiz if self.monospaced else self.font[offset] # Char width
+        offset += 1
+        for bit_vert in range(bv):   # for each vertical line
+            bytenum = bit_vert >> 3
+            bit = 1 << (bit_vert & 0x07)        # Faster than divmod
+            for bit_horiz in range(bh): #  horizontal line
+                fontbyte = self.font[offset + self.bytes_vert * bit_horiz + bytenum]
+                z = '*' if fontbyte & bit else ' '
+                print(z, end='')
+#                self.setpixelfast(self.char_x +bit_horiz, self.char_y +bit_vert, (fontbyte & bit) > 0)
+            print()
+#        self.char_x += bh                       # Somehow account for width of current char
+
+    def test(self, s):
+        for c in s:
+            self.render(ord(c))