Alternative .py writer

font_to_py/alt_writer.py

@@ -25,51 +25,39 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
-import importlib.metadata
 import sys
 from pathlib import Path
 
 import click
 import freetype
 
-from .byte_writer import ByteWriter
+from .byte_writer import AltByteWriter
 from .font import Font
 
-VERSION = importlib.metadata.version("micropython-font-to-py")
+HEADER_TPL = """# Code generated by font_to_py.
-
-
-# Define a global
-def var_write(stream, name, value):
-    stream.write(f"{name} = {value}\n")
-
-
-STR01 = """# Code generated by font_to_py.
 # Font: {font:s}{charset:s}
 # Cmd: {cmd:s}
-version = '{version:s}'
 
 """
 
 # Code emitted for charsets spanning a small range of ordinal values
-STR02 = """_mvfont = memoryview(_font)
+GET_CH_I_TPL = """def get_ch(self, ch):
-_mvi = memoryview(_index)
+    def ifb(l):
-ifb = lambda l : l[0] | (l[1] << 8)
+        return l[0] | (l[1] << 8)
 
-def get_ch(ch):
     oc = ord(ch)
-    ioff = 2 * (oc - {min:d} + 1) if oc >= {min:d} and oc <= {max:d} else 0
+    ioff = 2 * (oc - 32 + 1) if oc >= self.min_ch and oc <= self.max_ch else 0
-    doff = ifb(_mvi[ioff : ])
+    doff = ifb(self._index[ioff:])
-    width = ifb(_mvfont[doff : ])
+    width = ifb(self._font[doff:])"""
-"""
 
 # Code emiited for large charsets, assumed by build_arrays() to be sparse.
 # Binary search of sorted sparse index.
 # Offset into data array is saved after dividing by 8
-STRSP = """_mvfont = memoryview(_font)
+GET_CH_S_TPL = """def get_ch(self, ch):
-_mvsp = memoryview(_sparse)
+    def ifb(l):
-ifb = lambda l : l[0] | (l[1] << 8)
+        return l[0] | (l[1] << 8)
 
-def bs(lst, val):
+    def bs(lst, val):
         while True:
             m = (len(lst) & ~ 7) >> 1
             v = ifb(lst[m:])
@@ -79,39 +67,103 @@ def bs(lst, val):
                 return 0
             lst = lst[m:] if v < val else lst[:m]
 
-def get_ch(ch):
+    doff = bs(self._sparse, ord(ch)) << 3
-    doff = bs(_mvsp, ord(ch)) << 3
+    width = ifb(self._font[doff : ])"""
-    width = ifb(_mvfont[doff : ])
-"""
 
 # Code emitted for horizontally mapped fonts.
-STR02H = """
+GET_CH_HMAP_TPL = """   
-    next_offs = doff + 2 + ((width - 1)//8 + 1) * {height:d}
+    next_offs = doff + 2 + ((width - 1)//8 + 1) * self.height
-    return _mvfont[doff + 2:next_offs], {height:d}, width
+    return _mvfont[doff + 2:next_offs], self.height, width
 
 """
 
 # Code emitted for vertically mapped fonts.
-STR02V = """
+GET_CH_VMAP_TPL = """
-    next_offs = doff + 2 + (({height:d} - 1)//8 + 1) * width
+    next_offs = doff + 2 + ((self.height - 1)//8 + 1) * width
-    return _mvfont[doff + 2:next_offs], {height:d}, width
+    return _mvfont[doff + 2:next_offs], self.height, width
 
 """
 
 # Extra code emitted where -i is specified.
-STR03 = '''
+GLYPH_TPL = '''
-def glyphs():
+def glyphs(self):
-    for c in """{}""":
+    for c in """{keys:s}""":
-        yield c, get_ch(c)
+        yield c, self.get_ch(c)
 
 '''
 
+OBJECT_BEGIN_TPL = """font = type(
+    "",
+    (object,),
+    {
+"""
 
-def write_func(stream, name, arg):
+OBJECT_END_TPL = """    },
-    stream.write(f"def {name}():\n    return {arg}\n\n")
+)()
+"""
 
 
-def write_font(  # noqa: PLR0913
+def write_attribute(stream, name, value, indent=8):
+    stream.write(" " * indent + f'"{name}": {value},\n')
+
+
+def write_data(  # noqa: PLR0913
+    stream, fnt, font_path, hmap, reverse, iterate, charset
+):
+    height = fnt.height  # Actual height, not target height
+    minchar = min(fnt.crange)
+    maxchar = max(fnt.crange)
+    st = "" if charset == "" else f" Char set: {charset}"
+    cl = " ".join([str(Path(sys.argv[0]).stem), *sys.argv[1:]])
+    stream.write(HEADER_TPL.format(font=Path(font_path).stem, charset=st, cmd=cl))
+
+    data, index, sparse = fnt.build_arrays(hmap, reverse)
+
+    if sparse:  # build_arrays() has returned a sparse index
+        click.echo("Sparse")
+        stream.write(GET_CH_S_TPL)
+    else:
+        click.echo("Normal")
+        stream.write(GET_CH_I_TPL)
+
+    if hmap:
+        stream.write(GET_CH_HMAP_TPL)
+    else:
+        stream.write(GET_CH_VMAP_TPL)
+
+    if iterate:
+        stream.write(GLYPH_TPL.format(keys="".join(sorted(fnt.keys()))))
+
+    stream.write(OBJECT_BEGIN_TPL)
+    write_attribute(stream, "height", height)
+    write_attribute(stream, "baseline", fnt._max_ascent)
+    write_attribute(stream, "max_width", fnt.max_width)
+    write_attribute(stream, "hmap", hmap)
+    write_attribute(stream, "reverse", reverse)
+    write_attribute(stream, "monospaced", fnt.monospaced)
+    write_attribute(stream, "min_ch", minchar)
+    write_attribute(stream, "max_ch", maxchar)
+
+    bw_font = AltByteWriter(stream, "_font")
+    bw_font.odata(data)
+    bw_font.eot()
+
+    if sparse:  # build_arrays() has returned a sparse index
+        bw_sparse = AltByteWriter(stream, "_sparse")
+        bw_sparse.odata(sparse)
+        bw_sparse.eot()
+    else:
+        bw_index = AltByteWriter(stream, "_index")
+        bw_index.odata(index)
+        bw_index.eot()
+
+    write_attribute(stream, "get_ch", "get_ch")
+    if iterate:
+        write_attribute(stream, "glyphs", "glyphs")
+    stream.write(OBJECT_END_TPL)
+
+
+def write_alt_font(  # noqa: PLR0913
     op_path,
     font_path,
     height,
@@ -139,73 +191,3 @@ def write_font(  # noqa: PLR0913
         click.echo(f"Can't open {op_path} for writing")
         return False
     return True
-
-
-def write_data(  # noqa: PLR0913
-    stream, fnt, font_path, hmap, reverse, iterate, charset
-):
-    height = fnt.height  # Actual height, not target height
-    minchar = min(fnt.crange)
-    maxchar = max(fnt.crange)
-    st = "" if charset == "" else f" Char set: {charset}"
-    cl = " ".join([str(Path(sys.argv[0]).stem), *sys.argv[1:]])
-    stream.write(
-        STR01.format(font=Path(font_path).stem, charset=st, cmd=cl, version=VERSION)
-    )
-    write_func(stream, "height", height)
-    write_func(stream, "baseline", fnt._max_ascent)
-    write_func(stream, "max_width", fnt.max_width)
-    write_func(stream, "hmap", hmap)
-    write_func(stream, "reverse", reverse)
-    write_func(stream, "monospaced", fnt.monospaced)
-    write_func(stream, "min_ch", minchar)
-    write_func(stream, "max_ch", maxchar)
-    if iterate:
-        stream.write(STR03.format("".join(sorted(fnt.keys()))))
-    data, index, sparse = fnt.build_arrays(hmap, reverse)
-    bw_font = ByteWriter(stream, "_font")
-    bw_font.odata(data)
-    bw_font.eot()
-    if sparse:  # build_arrays() has returned a sparse index
-        bw_sparse = ByteWriter(stream, "_sparse")
-        bw_sparse.odata(sparse)
-        bw_sparse.eot()
-        stream.write(STRSP)
-        click.echo("Sparse")
-    else:
-        bw_index = ByteWriter(stream, "_index")
-        bw_index.odata(index)
-        bw_index.eot()
-        stream.write(STR02.format(min=minchar, max=maxchar))
-        click.echo("Normal")
-    if hmap:
-        stream.write(STR02H.format(height=height))
-    else:
-        stream.write(STR02V.format(height=height))
-
-
-# BINARY OUTPUT
-# hmap reverse magic bytes
-# 0    0       0x3f 0xe7
-# 1    0       0x40 0xe7
-# 0    1       0x41 0xe7
-# 1    1       0x42 0xe7
-def write_binary_font(op_path, font_path, height, hmap, reverse):
-    try:
-        fnt = Font(
-            font_path, height, 32, 126, True, None, ""
-        )  # All chars have same width
-    except freetype.ft_errors.FT_Exception:
-        click.echo(f"Can't open {font_path}")
-        return False
-    sig = 1 if hmap else 0
-    if reverse:
-        sig += 2
-    try:
-        with open(op_path, "wb") as stream:
-            data = fnt.build_binary_array(hmap, reverse, sig)
-            stream.write(data)
-    except OSError:
-        click.echo(f"Can't open {op_path} for writing")
-        return False
-    return True

font_to_py/byte_writer.py

@@ -63,3 +63,25 @@ class ByteWriter:
         if self.bytecount:
             self._eot()
         self.stream.write("\n")
+
+
+class AltByteWriter(ByteWriter):
+    def __init__(self, stream, varname, indent=8):
+        self.stream = stream
+        self.indent = indent
+        self.stream.write(" " * self.indent + f'"{varname}": memoryview(\n')
+        self.bytecount = 0  # For line breaks
+
+    def _eol(self):
+        self.stream.write('"\n')
+
+    def _eot(self):
+        self.stream.write('"\n')
+        self.stream.write(" " * self.indent + "),\n")
+
+    def _bol(self):
+        self.stream.write(" " * (self.indent + 4) + 'b"')
+
+    def eot(self):  # User force EOL if one hasn't occurred
+        if self.bytecount:
+            self._eot()

font_to_py/cli.py

@@ -34,6 +34,7 @@ from pathlib import Path
 import click
 import freetype
 
+from .alt_writer import write_alt_font
 from .bin_writer import write_binary_font
 from .py_writer import write_font
 
@@ -72,6 +73,12 @@ CONTEXT_SETTINGS = dict(max_content_width=100)
     is_flag=True,
     help="Produce binary (random access) font file.",
 )
+@click.option(
+    "-a",
+    "--alt",
+    is_flag=True,
+    help="Use alt python writer (EXPERIMENTAL).",
+)
 @click.option(
     "-i",
     "--iterate",
@@ -124,6 +131,7 @@ def main(  # noqa: C901, PLR0913, PLR0912
     reverse,
     fixed,
     binary,
+    alt,
     iterate,
     smallest,
     largest,
@@ -205,7 +213,8 @@ def main(  # noqa: C901, PLR0913, PLR0912
             click.echo(f"Found font with size {height!s}")
 
         click.echo("Writing Python font file.")
-        if not write_font(
+        if alt:
+            res = write_alt_font(
                 outfile,
                 infile,
                 height,
@@ -218,7 +227,24 @@ def main(  # noqa: C901, PLR0913, PLR0912
                 cset,
                 iterate,
                 bitmapped,
-        ):
+            )
+        else:
+            res = write_font(
+                outfile,
+                infile,
+                height,
+                fixed,
+                xmap,
+                reverse,
+                smallest,
+                largest,
+                errchar,
+                cset,
+                iterate,
+                bitmapped,
+            )
+
+        if not res:
             sys.exit(1)
 
     click.echo(f"{outfile} written successfully.")

font_to_py/py_writer.py

@@ -37,12 +37,6 @@ from .font import Font
 
 VERSION = importlib.metadata.version("micropython-font-to-py")
 
-
-# Define a global
-def var_write(stream, name, value):
-    stream.write(f"{name} = {value}\n")
-
-
 STR01 = """# Code generated by font_to_py.
 # Font: {font:s}{charset:s}
 # Cmd: {cmd:s}
@@ -107,6 +101,11 @@ def glyphs():
 '''
 
 
+# Define a global
+def var_write(stream, name, value):
+    stream.write(f"{name} = {value}\n")
+
+
 def write_func(stream, name, arg):
     stream.write(f"def {name}():\n    return {arg}\n\n")