Tasmota/lib/libesp32_epdiy/scripts/fontconvert.py

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2021-04-03 15:58:47 +01:00
#!python3
import freetype
import zlib
import sys
import re
import math
import argparse
from collections import namedtuple
parser = argparse.ArgumentParser(description="Generate a header file from a font to be used with epdiy.")
parser.add_argument("name", action="store", help="name of the font.")
parser.add_argument("size", type=int, help="font size to use.")
parser.add_argument("fontstack", action="store", nargs='+', help="list of font files, ordered by descending priority.")
parser.add_argument("--compress", dest="compress", action="store_true", help="compress glyph bitmaps.")
parser.add_argument("--additional-intervals", dest="additional_intervals", action="append", help="Additional code point intervals to export as min,max. This argument can be repeated.")
args = parser.parse_args()
GlyphProps = namedtuple("GlyphProps", ["width", "height", "advance_x", "left", "top", "compressed_size", "data_offset", "code_point"])
font_stack = [freetype.Face(f) for f in args.fontstack]
compress = args.compress
size = args.size
font_name = args.name
# inclusive unicode code point intervals
# must not overlap and be in ascending order
intervals = [
(32, 126),
(160, 255),
# punctuation
(0x2010, 0x205F),
# arrows
(0x2190, 0x21FF),
# math
#(0x2200, 0x22FF),
# symbols
(0x2300, 0x23FF),
# box drawing
#(0x2500, 0x259F),
# geometric shapes
(0x25A0, 0x25FF),
# misc symbols
(0x2600, 0x26F0),
(0x2700, 0x27BF),
# powerline symbols
#(0xE0A0, 0xE0A2),
#(0xE0B0, 0xE0B3),
#(0x1F600, 0x1F680),
]
add_ints = []
if args.additional_intervals:
add_ints = [tuple([int(n, base=0) for n in i.split(",")]) for i in args.additional_intervals]
intervals = sorted(intervals + add_ints)
def norm_floor(val):
return int(math.floor(val / (1 << 6)))
def norm_ceil(val):
return int(math.ceil(val / (1 << 6)))
for face in font_stack:
# shift by 6 bytes, because sizes are given as 6-bit fractions
# the display has about 150 dpi.
face.set_char_size(size << 6, size << 6, 150, 150)
def chunks(l, n):
for i in range(0, len(l), n):
yield l[i:i + n]
total_size = 0
total_packed = 0
all_glyphs = []
def load_glyph(code_point):
face_index = 0
while face_index < len(font_stack):
face = font_stack[face_index]
glyph_index = face.get_char_index(code_point)
if glyph_index > 0:
face.load_glyph(glyph_index, freetype.FT_LOAD_RENDER)
return face
break
face_index += 1
print (f"falling back to font {face_index} for {chr(code_point)}.", file=sys.stderr)
raise ValueError(f"code point {code_point} not found in font stack!")
for i_start, i_end in intervals:
for code_point in range(i_start, i_end + 1):
face = load_glyph(code_point)
bitmap = face.glyph.bitmap
pixels = []
px = 0
for i, v in enumerate(bitmap.buffer):
y = i / bitmap.width
x = i % bitmap.width
if x % 2 == 0:
px = (v >> 4)
else:
px = px | (v & 0xF0)
pixels.append(px);
px = 0
# eol
if x == bitmap.width - 1 and bitmap.width % 2 > 0:
pixels.append(px)
px = 0
packed = bytes(pixels);
total_packed += len(packed)
compressed = packed
if compress:
compressed = zlib.compress(packed)
glyph = GlyphProps(
width = bitmap.width,
height = bitmap.rows,
advance_x = norm_floor(face.glyph.advance.x),
left = face.glyph.bitmap_left,
top = face.glyph.bitmap_top,
compressed_size = len(compressed),
data_offset = total_size,
code_point = code_point,
)
total_size += len(compressed)
all_glyphs.append((glyph, compressed))
# pipe seems to be a good heuristic for the "real" descender
face = load_glyph(ord('|'))
glyph_data = []
glyph_props = []
for index, glyph in enumerate(all_glyphs):
props, compressed = glyph
glyph_data.extend([b for b in compressed])
glyph_props.append(props)
print("total", total_packed, file=sys.stderr)
print("compressed", total_size, file=sys.stderr)
print("#pragma once")
print("#include \"epd_driver.h\"")
print(f"const uint8_t {font_name}Bitmaps[{len(glyph_data)}] = {{")
for c in chunks(glyph_data, 16):
print (" " + " ".join(f"0x{b:02X}," for b in c))
print ("};");
print(f"const EpdGlyph {font_name}Glyphs[] = {{")
for i, g in enumerate(glyph_props):
print (" { " + ", ".join([f"{a}" for a in list(g[:-1])]),"},", f"// {chr(g.code_point) if g.code_point != 92 else '<backslash>'}")
print ("};");
print(f"const EpdUnicodeInterval {font_name}Intervals[] = {{")
offset = 0
for i_start, i_end in intervals:
print (f" {{ 0x{i_start:X}, 0x{i_end:X}, 0x{offset:X} }},")
offset += i_end - i_start + 1
print ("};");
print(f"const EpdFont {font_name} = {{")
print(f" {font_name}Bitmaps,")
print(f" {font_name}Glyphs,")
print(f" {font_name}Intervals,")
print(f" {len(intervals)},")
print(f" {1 if compress else 0},")
print(f" {norm_ceil(face.size.height)},")
print(f" {norm_ceil(face.size.ascender)},")
print(f" {norm_floor(face.size.descender)},")
print("};")