kopia lustrzana https://github.com/peterhinch/micropython-font-to-py
577 wiersze
21 KiB
Python
Executable File
577 wiersze
21 KiB
Python
Executable File
#! /usr/bin/python3
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# -*- coding: utf-8 -*-
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# Needs freetype-py>=1.0
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# Implements multi-pass solution to setting an exact font height
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# Some code adapted from Daniel Bader's work at the following URL
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# http://dbader.org/blog/monochrome-font-rendering-with-freetype-and-python
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# The MIT License (MIT)
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#
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# Copyright (c) 2016 Peter Hinch
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#
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be included in
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# all copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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# THE SOFTWARE.
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import argparse
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import sys
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import os
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import freetype
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# UTILITIES FOR WRITING PYTHON SOURCECODE TO A FILE
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# ByteWriter takes as input a variable name and data values and writes
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# Python source to an output stream of the form
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# my_variable = b'\x01\x02\x03\x04\x05\x06\x07\x08'\
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# Lines are broken with \ for readability.
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class ByteWriter(object):
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bytes_per_line = 16
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def __init__(self, stream, varname):
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self.stream = stream
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self.stream.write('{} =\\\n'.format(varname))
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self.bytecount = 0 # For line breaks
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def _eol(self):
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self.stream.write("'\\\n")
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def _eot(self):
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self.stream.write("'\n")
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def _bol(self):
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self.stream.write("b'")
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# Output a single byte
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def obyte(self, data):
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if not self.bytecount:
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self._bol()
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self.stream.write('\\x{:02x}'.format(data))
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self.bytecount += 1
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self.bytecount %= self.bytes_per_line
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if not self.bytecount:
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self._eol()
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# Output from a sequence
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def odata(self, bytelist):
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for byt in bytelist:
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self.obyte(byt)
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# ensure a correct final line
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def eot(self): # User force EOL if one hasn't occurred
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if self.bytecount:
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self._eot()
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self.stream.write('\n')
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# Define a global
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def var_write(stream, name, value):
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stream.write('{} = {}\n'.format(name, value))
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# FONT HANDLING
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class Bitmap(object):
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"""
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A 2D bitmap image represented as a list of byte values. Each byte indicates
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the state of a single pixel in the bitmap. A value of 0 indicates that the
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pixel is `off` and any other value indicates that it is `on`.
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"""
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def __init__(self, width, height, pixels=None):
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self.width = width
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self.height = height
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self.pixels = pixels or bytearray(width * height)
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def display(self):
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"""Print the bitmap's pixels."""
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for row in range(self.height):
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for col in range(self.width):
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char = '#' if self.pixels[row * self.width + col] else '.'
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print(char, end='')
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print()
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print()
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def bitblt(self, src, row):
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"""Copy all pixels from `src` into this bitmap"""
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srcpixel = 0
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dstpixel = row * self.width
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row_offset = self.width - src.width
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for _ in range(src.height):
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for _ in range(src.width):
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self.pixels[dstpixel] = src.pixels[srcpixel]
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srcpixel += 1
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dstpixel += 1
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dstpixel += row_offset
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# Horizontal mapping generator function
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def get_hbyte(self, reverse):
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for row in range(self.height):
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col = 0
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while True:
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bit = col % 8
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if bit == 0:
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if col >= self.width:
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break
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byte = 0
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if col < self.width:
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if reverse:
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byte |= self.pixels[row * self.width + col] << bit
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else:
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# Normal map MSB of byte 0 is (0, 0)
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byte |= self.pixels[row * self.width + col] << (7 - bit)
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if bit == 7:
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yield byte
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col += 1
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# Vertical mapping
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def get_vbyte(self, reverse):
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for col in range(self.width):
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row = 0
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while True:
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bit = row % 8
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if bit == 0:
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if row >= self.height:
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break
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byte = 0
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if row < self.height:
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if reverse:
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byte |= self.pixels[row * self.width + col] << (7 - bit)
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else:
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# Normal map MSB of byte 0 is (0, 7)
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byte |= self.pixels[row * self.width + col] << bit
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if bit == 7:
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yield byte
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row += 1
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class Glyph(object):
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def __init__(self, pixels, width, height, top, advance_width):
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self.bitmap = Bitmap(width, height, pixels)
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# The glyph bitmap's top-side bearing, i.e. the vertical distance from
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# the baseline to the bitmap's top-most scanline.
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self.top = top
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# Ascent and descent determine how many pixels the glyph extends
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# above or below the baseline.
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self.descent = max(0, self.height - self.top)
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self.ascent = max(0, max(self.top, self.height) - self.descent)
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# The advance width determines where to place the next character
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# horizontally, that is, how many pixels we move to the right to
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# draw the next glyph.
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self.advance_width = advance_width
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@property
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def width(self):
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return self.bitmap.width
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@property
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def height(self):
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return self.bitmap.height
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@staticmethod
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def from_glyphslot(slot):
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"""Construct and return a Glyph object from a FreeType GlyphSlot."""
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pixels = Glyph.unpack_mono_bitmap(slot.bitmap)
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width, height = slot.bitmap.width, slot.bitmap.rows
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top = slot.bitmap_top
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# The advance width is given in FreeType's 26.6 fixed point format,
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# which means that the pixel values are multiples of 64.
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advance_width = slot.advance.x / 64
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return Glyph(pixels, width, height, top, advance_width)
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@staticmethod
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def unpack_mono_bitmap(bitmap):
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"""
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Unpack a freetype FT_LOAD_TARGET_MONO glyph bitmap into a bytearray
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where each pixel is represented by a single byte.
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"""
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# Allocate a bytearray of sufficient size to hold the glyph bitmap.
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data = bytearray(bitmap.rows * bitmap.width)
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# Iterate over every byte in the glyph bitmap. Note that we're not
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# iterating over every pixel in the resulting unpacked bitmap --
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# we're iterating over the packed bytes in the input bitmap.
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for row in range(bitmap.rows):
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for byte_index in range(bitmap.pitch):
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# Read the byte that contains the packed pixel data.
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byte_value = bitmap.buffer[row * bitmap.pitch + byte_index]
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# We've processed this many bits (=pixels) so far. This
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# determines where we'll read the next batch of pixels from.
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num_bits_done = byte_index * 8
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# Pre-compute where to write the pixels that we're going
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# to unpack from the current byte in the glyph bitmap.
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rowstart = row * bitmap.width + byte_index * 8
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# Iterate over every bit (=pixel) that's still a part of the
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# output bitmap. Sometimes we're only unpacking a fraction of
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# a byte because glyphs may not always fit on a byte boundary.
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# So we make sure to stop if we unpack past the current row
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# of pixels.
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for bit_index in range(min(8, bitmap.width - num_bits_done)):
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# Unpack the next pixel from the current glyph byte.
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bit = byte_value & (1 << (7 - bit_index))
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# Write the pixel to the output bytearray. We ensure that
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# `off` pixels have a value of 0 and `on` pixels have a
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# value of 1.
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data[rowstart + bit_index] = 1 if bit else 0
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return data
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# A Font object is a dictionary of ASCII chars indexed by a character e.g.
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# myfont['a']
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# Each entry comprises a list
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# [0] A Bitmap instance containing the character
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# [1] The width of the character data including advance (actual data stored)
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# Public attributes:
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# height (in pixels) of all characters
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# width (in pixels) for monospaced output (advance width of widest char)
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class Font(dict):
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def __init__(self, filename, size, minchar, maxchar, monospaced, defchar, charset):
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super().__init__()
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self._face = freetype.Face(filename)
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self.minchar = minchar
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self.maxchar = maxchar
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self.monospaced = monospaced
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# .def_charset is requested charset or '' if -c was not specified
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self.def_charset = charset
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# .charset has all defined characters with '' for those in range but undefined.
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if defchar is None: # Binary font
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self.charset = [chr(char) for char in range(minchar, maxchar + 1)]
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elif charset == '':
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self.charset = [chr(defchar)] + [chr(char) for char in range(minchar, maxchar + 1)]
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else:
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n = sorted([ord(x) for x in chr(defchar) + charset])
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self.minchar = n[0]
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self.maxchar = n[-1]
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self.charset = [chr(defchar)] + [chr(char) if chr(char) in charset else '' for char in range(n[0], n[-1] + 1)]
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# .pop_charset has only the defined characters
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self.pop_charset = [c for c in self.charset if c]
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self.max_width = self.get_dimensions(size)
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self.width = self.max_width if monospaced else 0
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for char in self.pop_charset: # Populate dictionary
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self._render_char(char)
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# n-pass solution to setting a precise height.
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def get_dimensions(self, required_height):
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error = 0
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height = required_height
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for npass in range(10):
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height += error
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self._face.set_pixel_sizes(0, height)
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max_descent = 0
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# For each character in the charset string we get the glyph
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# and update the overall dimensions of the resulting bitmap.
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max_width = 0
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max_ascent = 0
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for char in self.pop_charset:
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glyph = self._glyph_for_character(char)
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max_ascent = max(max_ascent, glyph.ascent)
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max_descent = max(max_descent, glyph.descent)
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# for a few chars e.g. _ glyph.width > glyph.advance_width
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max_width = int(max(max_width, glyph.advance_width,
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glyph.width))
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new_error = required_height - (max_ascent + max_descent)
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if (new_error == 0) or (abs(new_error) - abs(error) == 0):
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break
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error = new_error
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self.height = int(max_ascent + max_descent)
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st = 'Height set in {} passes. Actual height {} pixels.\nMax character width {} pixels.'
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print(st.format(npass + 1, self.height, max_width))
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self._max_descent = int(max_descent)
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return max_width
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def _glyph_for_character(self, char):
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# Let FreeType load the glyph for the given character and tell it to
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# render a monochromatic bitmap representation.
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assert char != ''
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self._face.load_char(char, freetype.FT_LOAD_RENDER |
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freetype.FT_LOAD_TARGET_MONO)
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return Glyph.from_glyphslot(self._face.glyph)
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def _render_char(self, char):
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if char:
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glyph = self._glyph_for_character(char)
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char_width = int(max(glyph.width, glyph.advance_width)) # Actual width
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width = self.width if self.width else char_width # Space required if monospaced
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outbuffer = Bitmap(width, self.height)
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# The vertical drawing position should place the glyph
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# on the baseline as intended.
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row = self.height - int(glyph.ascent) - self._max_descent
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outbuffer.bitblt(glyph.bitmap, row)
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self[char] = [outbuffer, width, char_width]
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def stream_char(self, char, hmap, reverse):
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outbuffer, _, _ = self[char]
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if hmap:
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gen = outbuffer.get_hbyte(reverse)
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else:
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gen = outbuffer.get_vbyte(reverse)
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yield from gen
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def build_arrays(self, hmap, reverse):
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data = bytearray()
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index = bytearray() #((0, 0))
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for char in self.charset:
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if char == '':
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index += bytearray((0, 0, 0, 0))
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index[-1] = index[3]
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index[-2] = index[2]
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else:
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index += (len(data)).to_bytes(2, byteorder='little') # Start
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width = self[char][1]
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data += (width).to_bytes(2, byteorder='little')
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data += bytearray(self.stream_char(char, hmap, reverse))
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index += (len(data)).to_bytes(2, byteorder='little') # End
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return data, index
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def build_binary_array(self, hmap, reverse, sig):
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data = bytearray((0x3f + sig, 0xe7, self.max_width, self.height))
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for char in self.charset:
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width = self[char][2]
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data += bytes((width,))
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data += bytearray(self.stream_char(char, hmap, reverse))
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return data
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# PYTHON FILE WRITING
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STR01 = """# Code generated by font-to-py.py.
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# Font: {}{}
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version = '0.25'
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"""
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STR02 = """_mvfont = memoryview(_font)
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def get_ch(ch):
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ordch = ord(ch)
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ordch = ordch + 1 if ordch >= {} and ordch <= {} else {}
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idx_offs = 4 * (ordch - {})
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offset = int.from_bytes(_index[idx_offs : idx_offs + 2], 'little')
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next_offs = int.from_bytes(_index[idx_offs + 2 : idx_offs + 4], 'little')
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width = int.from_bytes(_font[offset:offset + 2], 'little')
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return _mvfont[offset + 2:next_offs], {}, width
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"""
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def write_func(stream, name, arg):
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stream.write('def {}():\n return {}\n\n'.format(name, arg))
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# filename, size, minchar=32, maxchar=126, monospaced=False, defchar=ord('?'):
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def write_font(op_path, font_path, height, monospaced, hmap, reverse, minchar, maxchar, defchar, charset):
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try:
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fnt = Font(font_path, height, minchar, maxchar, monospaced, defchar, charset)
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except freetype.ft_errors.FT_Exception:
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print("Can't open", font_path)
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return False
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try:
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with open(op_path, 'w') as stream:
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write_data(stream, fnt, font_path, hmap, reverse)
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except OSError:
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print("Can't open", op_path, 'for writing')
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return False
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return True
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def write_data(stream, fnt, font_path, hmap, reverse):
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height = fnt.height # Actual height, not target height
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minchar = fnt.minchar
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maxchar = fnt.maxchar
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charset = fnt.def_charset
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st = '' if charset == '' else ' Char set: {}'.format(charset)
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stream.write(STR01.format(os.path.split(font_path)[1], st))
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stream.write('\n')
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write_func(stream, 'height', height)
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write_func(stream, 'max_width', fnt.max_width)
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write_func(stream, 'hmap', hmap)
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write_func(stream, 'reverse', reverse)
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write_func(stream, 'monospaced', fnt.monospaced)
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write_func(stream, 'min_ch', minchar)
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write_func(stream, 'max_ch', maxchar)
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data, index = fnt.build_arrays(hmap, reverse)
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bw_font = ByteWriter(stream, '_font')
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bw_font.odata(data)
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bw_font.eot()
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bw_index = ByteWriter(stream, '_index')
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bw_index.odata(index)
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bw_index.eot()
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stream.write(STR02.format(minchar, maxchar, minchar, minchar, height))
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# BINARY OUTPUT
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# hmap reverse magic bytes
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# 0 0 0x3f 0xe7
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# 1 0 0x40 0xe7
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# 0 1 0x41 0xe7
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# 1 1 0x42 0xe7
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def write_binary_font(op_path, font_path, height, hmap, reverse):
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try:
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fnt = Font(font_path, height, 32, 126, True, None, '') # All chars have same width
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except freetype.ft_errors.FT_Exception:
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print("Can't open", font_path)
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return False
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sig = 1 if hmap else 0
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if reverse:
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sig += 2
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try:
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with open(op_path, 'wb') as stream:
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data = fnt.build_binary_array(hmap, reverse, sig)
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stream.write(data)
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except OSError:
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print("Can't open", op_path, 'for writing')
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return False
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return True
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# PARSE COMMAND LINE ARGUMENTS
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def quit(msg):
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print(msg)
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sys.exit(1)
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DESC = """font_to_py.py
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Utility to convert ttf or otf font files to Python source.
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Sample usage:
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font_to_py.py FreeSans.ttf 23 freesans.py
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This creates a font with nominal height 23 pixels with these defaults:
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Mapping is vertical, pitch variable, character set 32-126 inclusive.
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Illegal characters will be rendered as "?".
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To specify monospaced rendering issue:
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font_to_py.py FreeSans.ttf 23 --fixed freesans.py
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"""
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BINARY = """Invalid arguments. Binary (random access) font files support the standard ASCII
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character set (from 32 to 126 inclusive). This range cannot be overridden.
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Random access font files don't support an error character.
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"""
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if __name__ == "__main__":
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parser = argparse.ArgumentParser(__file__, description=DESC,
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formatter_class=argparse.RawDescriptionHelpFormatter)
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parser.add_argument('infile', type=str, help='Input file path')
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parser.add_argument('height', type=int, help='Font height in pixels')
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parser.add_argument('outfile', type=str,
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help='Path and name of output file')
|
|
|
|
parser.add_argument('-x', '--xmap', action='store_true',
|
|
help='Horizontal (x) mapping')
|
|
parser.add_argument('-r', '--reverse', action='store_true',
|
|
help='Bit reversal')
|
|
parser.add_argument('-f', '--fixed', action='store_true',
|
|
help='Fixed width (monospaced) font')
|
|
parser.add_argument('-b', '--binary', action='store_true',
|
|
help='Produce binary (random access) font file.')
|
|
|
|
parser.add_argument('-s', '--smallest',
|
|
type = int,
|
|
default = 32,
|
|
help = 'Ordinal value of smallest character default %(default)i')
|
|
|
|
parser.add_argument('-l', '--largest',
|
|
type = int,
|
|
help = 'Ordinal value of largest character default %(default)i',
|
|
default = 126)
|
|
|
|
parser.add_argument('-e', '--errchar',
|
|
type = int,
|
|
help = 'Ordinal value of error character default %(default)i ("?")',
|
|
default = 63)
|
|
|
|
parser.add_argument('-c', '--charset',
|
|
type = str,
|
|
help = 'Character set. e.g. 1234567890: to restrict for a clock display.',
|
|
default = '')
|
|
|
|
parser.add_argument('-k', '--charset_file',
|
|
type = str,
|
|
help = 'File containing charset e.g. cyrillic_subset.',
|
|
default = '')
|
|
|
|
args = parser.parse_args()
|
|
if not args.infile[0].isalpha():
|
|
quit('Font filenames must be valid Python variable names.')
|
|
|
|
if not os.path.isfile(args.infile):
|
|
quit("Font filename does not exist")
|
|
|
|
if not os.path.splitext(args.infile)[1].upper() in ('.TTF', '.OTF'):
|
|
quit("Font file should be a ttf or otf file.")
|
|
|
|
if args.binary:
|
|
if os.path.splitext(args.outfile)[1].upper() == '.PY':
|
|
quit('Binary file must not have a .py extension.')
|
|
|
|
if args.smallest != 32 or args.largest != 126 or args.errchar != ord('?') or args.charset:
|
|
quit(BINARY)
|
|
|
|
print('Writing binary font file.')
|
|
if not write_binary_font(args.outfile, args.infile, args.height,
|
|
args.xmap, args.reverse):
|
|
sys.exit(1)
|
|
else:
|
|
if not os.path.splitext(args.outfile)[1].upper() == '.PY':
|
|
quit('Output filename must have a .py extension.')
|
|
|
|
if args.smallest < 0:
|
|
quit('--smallest must be >= 0')
|
|
|
|
if args.largest > 255:
|
|
quit('--largest must be < 256')
|
|
elif args.largest > 127 and os.path.splitext(args.infile)[1].upper() == '.TTF':
|
|
print('WARNING: extended ASCII characters may not be correctly converted. See docs.')
|
|
|
|
if args.errchar < 0 or args.errchar > 255:
|
|
quit('--errchar must be between 0 and 255')
|
|
if args.charset and (args.smallest != 32 or args.largest != 126):
|
|
print('WARNING: specified smallest and largest values ignored.')
|
|
|
|
if args.charset_file:
|
|
try:
|
|
with open(args.charset_file, 'r') as f:
|
|
cset = f.read()
|
|
except OSError:
|
|
print("Can't open", args.charset_file, 'for reading.')
|
|
sys.exit(1)
|
|
else:
|
|
cset = args.charset
|
|
print('Writing Python font file.')
|
|
if not write_font(args.outfile, args.infile, args.height, args.fixed,
|
|
args.xmap, args.reverse, args.smallest, args.largest,
|
|
args.errchar, cset):
|
|
sys.exit(1)
|
|
|
|
print(args.outfile, 'written successfully.')
|
|
|