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trezor-firmware/core/tools/codegen/gen_font.py
2023-05-31 10:14:54 +02:00

233 lines
8.1 KiB
Python
Executable File

#!/usr/bin/env python3
# script used to generate /embed/extmod/modtrezorui/font_*_*.c
from __future__ import annotations
from pathlib import Path
import freetype
HERE = Path(__file__).parent
FONTS_DIR = HERE / "fonts"
MIN_GLYPH = ord(" ")
MAX_GLYPH = ord("~")
# metrics explanation: https://www.freetype.org/freetype2/docs/glyphs/metrics.png
def process_bitmap_buffer(buf: list[int], bpp: int) -> list[int]:
res = buf[:]
if bpp == 1:
for _ in range(8 - len(res) % 8):
res.append(0)
res = [
(
(a & 0x80)
| ((b & 0x80) >> 1)
| ((c & 0x80) >> 2)
| ((d & 0x80) >> 3)
| ((e & 0x80) >> 4)
| ((f & 0x80) >> 5)
| ((g & 0x80) >> 6)
| ((h & 0x80) >> 7)
)
for a, b, c, d, e, f, g, h in [
res[i : i + 8] for i in range(0, len(res), 8)
]
]
elif bpp == 2:
for _ in range(4 - len(res) % 4):
res.append(0)
res = [
((a & 0xC0) | ((b & 0xC0) >> 2) | ((c & 0xC0) >> 4) | ((d & 0xC0) >> 6))
for a, b, c, d in [res[i : i + 4] for i in range(0, len(res), 4)]
]
elif bpp == 4:
if len(res) % 2 > 0:
res.append(0)
res = [
((a & 0xF0) | (b >> 4))
for a, b in [res[i : i + 2] for i in range(0, len(res), 2)]
]
elif bpp == 8:
pass
else:
raise ValueError
return res
def drop_left_columns(buf: list[int], width: int, drop: int) -> list[int]:
res: list[int] = []
for i in range(len(buf)):
if i % width >= drop:
res.append(buf[i])
return res
def process_face(
name: str,
style: str,
size: int,
bpp: int = 4,
shaveX: int = 0,
ext: str = "ttf",
) -> None:
print("Processing ... %s %s %s" % (name, style, size))
file_name = FONTS_DIR / f"{name}-{style}.{ext}"
face = freetype.Face(str(file_name))
face.set_pixel_sizes(0, size)
fontname = "%s_%s_%d" % (name.lower(), style.lower(), size)
font_ymin = 0
font_ymax = 0
with open("font_%s.c" % fontname, "wt") as f:
f.write("#include <stdint.h>\n\n")
f.write("// clang-format off\n\n")
f.write("// - the first two bytes are width and height of the glyph\n")
f.write(
"// - the third, fourth and fifth bytes are advance, bearingX and bearingY of the horizontal metrics of the glyph\n"
)
f.write("// - the rest is packed %d-bit glyph data\n\n" % bpp)
for i in range(MIN_GLYPH, MAX_GLYPH + 1):
c = chr(i)
face.load_char(c, freetype.FT_LOAD_RENDER | freetype.FT_LOAD_TARGET_NORMAL)
bitmap = face.glyph.bitmap
metrics = face.glyph.metrics
assert metrics.width // 64 == bitmap.width
assert metrics.height // 64 == bitmap.rows
assert metrics.width % 64 == 0
assert metrics.height % 64 == 0
assert metrics.horiAdvance % 64 == 0
assert metrics.horiBearingX % 64 == 0
assert metrics.horiBearingY % 64 == 0
assert bitmap.width == bitmap.pitch
assert len(bitmap.buffer) == bitmap.pitch * bitmap.rows
width = bitmap.width
rows = bitmap.rows
advance = metrics.horiAdvance // 64
bearingX = metrics.horiBearingX // 64
remove_left = shaveX
# discard space on the left side
if shaveX > 0:
diff = min(advance, bearingX, shaveX)
advance -= diff
bearingX -= diff
remove_left -= diff
# the following code is here just for some letters (listed below)
# not using negative bearingX makes life so much easier; add it to advance instead
if bearingX < 0:
if c in "AXYjxy}),/_":
advance += -bearingX
bearingX = 0
else:
raise ValueError("Negative bearingX for character '%s'" % c)
bearingY = metrics.horiBearingY // 64
assert advance >= 0 and advance <= 255
assert bearingX >= 0 and bearingX <= 255
if bearingY < 0: # HACK
print("normalizing bearingY %d for '%s'" % (bearingY, c))
bearingY = 0
assert bearingY >= 0 and bearingY <= 255
buf = list(bitmap.buffer)
# discard non-space pixels on the left side
if remove_left > 0 and width > 0:
assert bearingX == 0
buf = drop_left_columns(buf, width, remove_left)
assert width > remove_left
width -= remove_left
assert advance > remove_left
advance -= remove_left
print(
'Glyph "%c": removed %d pixel columns from the left'
% (c, remove_left)
)
print(
'Loaded glyph "%c" ... %d x %d @ %d grays (%d bytes, metrics: %d, %d, %d)'
% (
c,
bitmap.width,
bitmap.rows,
bitmap.num_grays,
len(bitmap.buffer),
advance,
bearingX,
bearingY,
)
)
f.write(
"/* %c */ static const uint8_t Font_%s_%s_%d_glyph_%d[] = { %d, %d, %d, %d, %d"
% (c, name, style, size, i, width, rows, advance, bearingX, bearingY)
)
if len(buf) > 0:
f.write(
", "
+ ", ".join(["%d" % x for x in process_bitmap_buffer(buf, bpp)])
)
f.write(" };\n")
if i == ord("?"):
nonprintable = (
"\nconst uint8_t Font_%s_%s_%d_glyph_nonprintable[] = { %d, %d, %d, %d, %d"
% (name, style, size, width, rows, advance, bearingX, bearingY)
)
nonprintable += ", " + ", ".join(
["%d" % (x ^ 0xFF) for x in process_bitmap_buffer(buf, bpp)]
)
nonprintable += " };\n"
yMin = bearingY - rows
yMax = yMin + rows
font_ymin = min(font_ymin, yMin)
font_ymax = max(font_ymax, yMax)
f.write(nonprintable)
f.write(
"\nconst uint8_t * const Font_%s_%s_%d[%d + 1 - %d] = {\n"
% (name, style, size, MAX_GLYPH, MIN_GLYPH)
)
for i in range(MIN_GLYPH, MAX_GLYPH + 1):
f.write(" Font_%s_%s_%d_glyph_%d,\n" % (name, style, size, i))
f.write("};\n")
with open("font_%s.h" % fontname, "wt") as f:
f.write("#include <stdint.h>\n\n")
f.write("#if TREZOR_FONT_BPP != %d\n" % bpp)
f.write("#error Wrong TREZOR_FONT_BPP (expected %d)\n" % bpp)
f.write("#endif\n")
f.write("#define Font_%s_%s_%d_HEIGHT %d\n" % (name, style, size, size))
f.write(
"#define Font_%s_%s_%d_MAX_HEIGHT %d\n"
% (name, style, size, font_ymax - font_ymin)
)
f.write("#define Font_%s_%s_%d_BASELINE %d\n" % (name, style, size, -font_ymin))
f.write(
"extern const uint8_t* const Font_%s_%s_%d[%d + 1 - %d];\n"
% (name, style, size, MAX_GLYPH, MIN_GLYPH)
)
f.write(
"extern const uint8_t Font_%s_%s_%d_glyph_nonprintable[];\n"
% (name, style, size)
)
process_face("Roboto", "Regular", 20)
process_face("Roboto", "Bold", 20)
process_face("TTHoves", "Regular", 21, ext="otf")
process_face("TTHoves", "DemiBold", 21, ext="otf")
process_face("TTHoves", "Bold", 17, ext="otf")
process_face("RobotoMono", "Medium", 20)
process_face("PixelOperator", "Regular", 8, bpp=1, shaveX=1)
process_face("PixelOperator", "Bold", 8, bpp=1, shaveX=1)
process_face("PixelOperatorMono", "Regular", 8, bpp=1, shaveX=1)
# For model R
process_face("Unifont", "Regular", 16, bpp=1, shaveX=1, ext="otf")
process_face("Unifont", "Bold", 16, bpp=1, shaveX=1, ext="otf")