picowidget/ezFBfont.py
2024-11-19 20:19:14 +00:00

179 lines
7.0 KiB
Python

# ezFBfont.py() : a simple string writer for small mono displays and user selected fonts.
# See MARQUEE.md for documentation
# Extensively re-worked from the 'writer' class by
# Peter Hinch:
# https://github.com/peterhinch/micropython-font-to-py
# - Released under the MIT License (MIT). See LICENSE.
# - Copyright (c) 2019-2021 Peter Hinch
import framebuf
# Basic string writing class
class ezFBfont():
def __init__(self, device,
font,
fg = 1,
bg = 0,
tkey = -1,
halign = 'left',
valign = 'top',
vgap = 0,
hgap = 0,
split = '\n',
cswap = False,
verbose = False):
self._device = device
self._font = font
self.name = self._font.__name__
# font and color; only monochrome HLSB fonts are supported
self._font_format = framebuf.MONO_HLSB
self._font_colors = 2
self._palette_format = framebuf.RGB565 # support up to 65536 colors when blitting
# byte order for 16bit colors
self._cswap = cswap
# inform
if verbose:
fstr = '{} : initialised: height: {}, {} width: {}, baseline: {}'
print(fstr.format(self.name, self._font.height(),
'fixed' if self._font.monospaced() else 'max',
self._font.max_width(), self._font.baseline()))
# apply init color and alignment as default
self.set_default(fg, bg, tkey, halign, valign, hgap, vgap, split, verbose)
def _check_halign(self, h):
if h not in ('left','center','right'):
raise ValueError('Unknown horizontal alignment: ' + h)
return h
def _check_valign(self, v):
if v not in ('top','center','baseline','bottom'):
raise ValueError('Unknown vertical alignment: ' + v)
return v
def _line_size(self, string):
x = 0
for char in string:
_, _, char_width = self._font.get_ch(char)
x += char_width + self.hgap if char_width > 0 else 0
x = x - self.hgap if x != 0 else x # remove any trailing hgap
return x, self._font.height()
def _swap_bytes(self, color):
# flip the left and right bytes in a 16 bit color word if required
return ((color & 255) << 8) + (color >> 8) if self._cswap else color
def _put_char(self, char, x, y, fg, bg, tkey):
# fetch the glyph
glyph, char_height, char_width = self._font.get_ch(char)
if glyph is None:
return None, None # Nothing to write
# buffers
palette_buf = bytearray(self._font_colors * 2)
buf = bytearray(glyph)
# assemble color map
palette = framebuf.FrameBuffer(palette_buf, self._font_colors, 1, self._palette_format)
palette.pixel(0, 0, self._swap_bytes(bg))
palette.pixel(self._font_colors -1, 0, self._swap_bytes(fg))
# fetch and blit the glyph
charbuf = framebuf.FrameBuffer(buf, char_width, char_height, self._font_format)
self._device.blit(charbuf, x, y, tkey, palette)
return char_width, char_height
def set_default(self, fg=None, bg=None, tkey=None,
halign=None, valign=None, hgap=None, vgap=None, split=None, verbose=None):
# Sets the default value for all supplied arguments
self.fg = self.fg if fg is None else fg
self.bg = self.bg if bg is None else bg
self.tkey = self.tkey if tkey is None else tkey
self.halign = self.halign if halign is None else self._check_halign(halign)
self.valign = self.valign if valign is None else self._check_valign(valign)
self.hgap = self.hgap if hgap is None else hgap
self.vgap = self.vgap if vgap is None else vgap
self.split = self.split if split is None else split
self._verbose = self._verbose if verbose is None else verbose
if self._verbose:
fstr = '{} = fg: {}, bg: {}, tkey: {}, halign: {}, valign: {}, hgap: {}, vgap: {}, split: {}'
print(fstr.format(self.name, self.fg, self.bg, self.tkey,
self.halign, self.valign, self.hgap, self.vgap, repr(split)))
def size(self, string):
if len(string) == 0:
return 0, 0
lines = string.split(self.split)
w = 0
for line in lines:
x, _ = self._line_size(line)
w = max(w, x) # record the widest line
h = (len(lines) * (self._font.height() + self.vgap)) - self.vgap
return w, h
def rect(self, string, x, y, halign=None, valign=None):
if len(string) == 0:
return x, y, 0, 0
# apply alignment overrides
halign = self.halign if halign is None else self._check_halign(halign)
valign = self.valign if valign is None else self._check_valign(valign)
# get the x,y size of the rendered string
wide, high = self.size(string)
# apply alignment
xmin = x
if halign == 'center':
xmin = int(x - (wide / 2))
elif halign == 'right':
xmin = x - wide
ymin = y
if valign == 'baseline':
ymin = y - self._font.baseline()
elif valign == 'center':
ymin = int(y - (high / 2))
elif valign == 'bottom':
ymin = y - high
# return the result
return xmin,ymin,wide,high
def write(self, string, x, y, fg=None, bg=None, tkey=None,
halign=None, valign=None):
if len(string) == 0:
return True
all_chars = True
# Argument overrides
fg = self.fg if fg is None else fg
bg = self.bg if bg is None else bg
tkey = self.tkey if tkey is None else tkey
halign = self.halign if halign is None else self._check_halign(halign)
valign = self.valign if valign is None else self._check_valign(valign)
# Break the string into lines
lines = string.split(self.split)
# vertical alignment
high = (len(lines) * (self._font.height() + self.vgap)) - self.vgap
ypos = y
if valign == 'baseline':
ypos = y - self._font.baseline() + 1
elif valign == 'center':
ypos = int(y - (high / 2))
elif valign == 'bottom':
ypos = y - high
for line in lines:
wide, high = self._line_size(line)
# horizontal alignment
if halign == 'left':
xpos = x
elif halign == 'right':
xpos = x - wide
else:
xpos = int(x - (wide / 2))
# write the line
for char in line:
cx, _ = self._put_char(char, xpos, ypos, fg, bg, tkey)
if cx is None:
if self._verbose:
print('{}: missing char: {} (0x{:02X})'.format(self.name, repr(char), ord(char)))
all_chars = False
else:
xpos += cx + self.hgap
ypos += high + self.vgap
return all_chars