Adafruit_CircuitPython_Bitm.../adafruit_bitmap_font/bdf.py
2020-04-01 19:04:50 -05:00

194 lines
7.2 KiB
Python

# The MIT License (MIT)
#
# Copyright (c) 2019 Scott Shawcroft for Adafruit Industries LLC
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
"""
`adafruit_bitmap_font.bdf`
====================================================
Loads BDF format fonts.
* Author(s): Scott Shawcroft
Implementation Notes
--------------------
**Hardware:**
**Software and Dependencies:**
* Adafruit CircuitPython firmware for the supported boards:
https://github.com/adafruit/circuitpython/releases
"""
import gc
from fontio import Glyph
from .glyph_cache import GlyphCache
__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_Bitmap_Font.git"
class BDF(GlyphCache):
"""Loads glyphs from a BDF file in the given bitmap_class."""
def __init__(self, f, bitmap_class):
super().__init__()
self.file = f
self.name = f
self.file.seek(0)
self.bitmap_class = bitmap_class
line = self.file.readline()
line = str(line, "utf-8")
if not line or not line.startswith("STARTFONT 2.1"):
raise ValueError("Unsupported file version")
self.point_size = None
self.x_resolution = None
self.y_resolution = None
def get_bounding_box(self):
"""Return the maximum glyph size as a 4-tuple of: width, height, x_offset, y_offset"""
self.file.seek(0)
while True:
line = self.file.readline()
line = str(line, "utf-8")
if not line:
break
if line.startswith("FONTBOUNDINGBOX "):
_, x, y, x_offset, y_offset = line.split()
return (int(x), int(y), int(x_offset), int(y_offset))
return None
def load_glyphs(self, code_points):
# pylint: disable=too-many-statements,too-many-branches,too-many-nested-blocks,too-many-locals
metadata = True
character = False
code_point = None
bytes_per_row = 1
desired_character = False
current_info = {}
current_y = 0
rounded_x = 1
if isinstance(code_points, int):
remaining = set()
remaining.add(code_points)
elif isinstance(code_points, str):
remaining = set(ord(c) for c in code_points)
elif isinstance(code_points, set):
remaining = code_points
else:
remaining = set(code_points)
for code_point in remaining:
if code_point in self._glyphs and self._glyphs[code_point]:
remaining.remove(code_point)
if not remaining:
return
x, _, _, _ = self.get_bounding_box()
self.file.seek(0)
while True:
line = self.file.readline()
if not line:
break
if line.startswith(b"CHARS "):
metadata = False
elif line.startswith(b"SIZE"):
_, self.point_size, self.x_resolution, self.y_resolution = line.split()
elif line.startswith(b"COMMENT"):
pass
elif line.startswith(b"STARTCHAR"):
# print(lineno, line.strip())
# _, character_name = line.split()
character = True
elif line.startswith(b"ENDCHAR"):
character = False
if desired_character:
bounds = current_info["bounds"]
shift = current_info["shift"]
gc.collect()
self._glyphs[code_point] = Glyph(
current_info["bitmap"],
0,
bounds[0],
bounds[1],
bounds[2],
bounds[3],
shift[0],
shift[1],
)
remaining.remove(code_point)
if not remaining:
return
desired_character = False
elif line.startswith(b"BBX"):
if desired_character:
_, x, y, x_offset, y_offset = line.split()
x = int(x)
y = int(y)
x_offset = int(x_offset)
y_offset = int(y_offset)
current_info["bounds"] = (x, y, x_offset, y_offset)
current_info["bitmap"] = self.bitmap_class(x, y, 2)
elif line.startswith(b"BITMAP"):
if desired_character:
rounded_x = x // 8
if x % 8 > 0:
rounded_x += 1
bytes_per_row = rounded_x
if bytes_per_row % 4 > 0:
bytes_per_row += 4 - bytes_per_row % 4
current_y = 0
elif line.startswith(b"ENCODING"):
_, code_point = line.split()
code_point = int(code_point)
if code_point in remaining:
desired_character = True
current_info = {"bitmap": None, "bounds": None, "shift": None}
elif line.startswith(b"DWIDTH"):
if desired_character:
_, shift_x, shift_y = line.split()
shift_x = int(shift_x)
shift_y = int(shift_y)
current_info["shift"] = (shift_x, shift_y)
elif line.startswith(b"SWIDTH"):
pass
elif character:
if desired_character:
bits = int(line.strip(), 16)
width = current_info["bounds"][0]
start = current_y * width
x = 0
for i in range(rounded_x):
val = (bits >> ((rounded_x - i - 1) * 8)) & 0xFF
for j in range(7, -1, -1):
if x >= width:
break
bit = 0
if val & (1 << j) != 0:
bit = 1
current_info["bitmap"][start + x] = bit
x += 1
current_y += 1
elif metadata:
# print(lineno, line.strip())
pass