writer.py: Disallow glyph clipping.

master
Peter Hinch 2025-05-24 16:36:31 +01:00
rodzic e365a1076b
commit f79459e4cd
1 zmienionych plików z 42 dodań i 45 usunięć

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@ -1,6 +1,7 @@
# writer.py Implements the Writer class.
# Handles colour, word wrap and tab stops
# V0.5.2 May 2025 Fix bug whereby glyph clipping might be attempted.
# V0.5.1 Dec 2022 Support 4-bit color display drivers.
# V0.5.0 Sep 2021 Color now requires firmware >= 1.17.
# V0.4.3 Aug 2021 Support for fast blit to color displays (PR7682).
@ -23,24 +24,24 @@
import framebuf
from uctypes import bytearray_at, addressof
from sys import implementation
__version__ = (0, 5, 1)
__version__ = (0, 5, 2)
fast_mode = True # Does nothing. Kept to avoid breaking code.
class DisplayState():
class DisplayState:
def __init__(self):
self.text_row = 0
self.text_col = 0
def _get_id(device):
if not isinstance(device, framebuf.FrameBuffer):
raise ValueError('Device must be derived from FrameBuffer.')
raise ValueError("Device must be derived from FrameBuffer.")
return id(device)
# Basic Writer class for monochrome displays
class Writer():
class Writer:
state = {} # Holds a display state for each device
@ -52,13 +53,13 @@ class Writer():
s = Writer.state[devid] # Current state
if row is not None:
if row < 0 or row >= device.height:
raise ValueError('row is out of range')
raise ValueError("row is out of range")
s.text_row = row
if col is not None:
if col < 0 or col >= device.width:
raise ValueError('col is out of range')
raise ValueError("col is out of range")
s.text_col = col
return s.text_row, s.text_col
return s.text_row, s.text_col
def __init__(self, device, font, verbose=True):
self.devid = _get_id(device)
@ -67,16 +68,20 @@ class Writer():
Writer.state[self.devid] = DisplayState()
self.font = font
if font.height() >= device.height or font.max_width() >= device.width:
raise ValueError('Font too large for screen')
raise ValueError("Font too large for screen")
# Allow to work with reverse or normal font mapping
if font.hmap():
self.map = framebuf.MONO_HMSB if font.reverse() else framebuf.MONO_HLSB
else:
raise ValueError('Font must be horizontally mapped.')
raise ValueError("Font must be horizontally mapped.")
if verbose:
fstr = 'Orientation: Horizontal. Reversal: {}. Width: {}. Height: {}.'
fstr = "Orientation: Horizontal. Reversal: {}. Width: {}. Height: {}."
print(fstr.format(font.reverse(), device.width, device.height))
print('Start row = {} col = {}'.format(self._getstate().text_row, self._getstate().text_col))
print(
"Start row = {} col = {}".format(
self._getstate().text_row, self._getstate().text_col
)
)
self.screenwidth = device.width # In pixels
self.screenheight = device.height
self.bgcolor = 0 # Monochrome background and foreground colors
@ -90,7 +95,6 @@ class Writer():
self.glyph = None # Current char
self.char_height = 0
self.char_width = 0
self.clip_width = 0
def _getstate(self):
return Writer.state[self.devid]
@ -123,13 +127,13 @@ class Writer():
def printstring(self, string, invert=False):
# word wrapping. Assumes words separated by single space.
q = string.split('\n')
q = string.split("\n")
last = len(q) - 1
for n, s in enumerate(q):
if s:
self._printline(s, invert)
if n != last:
self._printchar('\n')
self._printchar("\n")
def _printline(self, string, invert):
rstr = None
@ -137,16 +141,16 @@ class Writer():
pos = 0
lstr = string[:]
while self.stringlen(lstr, True): # Length > self.screenwidth
pos = lstr.rfind(' ')
pos = lstr.rfind(" ")
lstr = lstr[:pos].rstrip()
if pos > 0:
rstr = string[pos + 1:]
rstr = string[pos + 1 :]
string = lstr
for char in string:
self._printchar(char, invert)
if rstr is not None:
self._printchar('\n')
self._printchar("\n")
self._printline(rstr, invert) # Recurse
def stringlen(self, string, oh=False):
@ -176,7 +180,7 @@ class Writer():
mc = 0 # Max non-blank column
data = glyph[(wd - 1) // 8] # Last byte of row 0
for row in range(ht): # Glyph row
for col in range(wd -1, -1, -1): # Glyph column
for col in range(wd - 1, -1, -1): # Glyph column
gbyte, gbit = divmod(col, 8)
if gbit == 0: # Next glyph byte
data = glyph[row * gbytes + gbyte]
@ -187,47 +191,42 @@ class Writer():
break
if mc + 1 == wd:
break # All done: no trailing space
# print('Truelen', char, wd, mc + 1) # TEST
# print('Truelen', char, wd, mc + 1) # TEST
return mc + 1
def _get_char(self, char, recurse):
if not recurse: # Handle tabs
if char == '\n':
if char == "\n":
self.cpos = 0
elif char == '\t':
elif char == "\t":
nspaces = self.tab - (self.cpos % self.tab)
if nspaces == 0:
nspaces = self.tab
while nspaces:
nspaces -= 1
self._printchar(' ', recurse=True)
self._printchar(" ", recurse=True)
self.glyph = None # All done
return
self.glyph = None # Assume all done
if char == '\n':
if char == "\n":
self._newline()
return
glyph, char_height, char_width = self.font.get_ch(char)
s = self._getstate()
np = None # Allow restriction on printable columns
if s.text_row + char_height > self.screenheight:
if self.row_clip:
return
self._newline()
oh = s.text_col + char_width - self.screenwidth # Overhang (+ve)
if oh > 0:
if s.text_col + char_width - self.screenwidth > 0: # Glyph would overhang
if self.col_clip or self.wrap:
np = char_width - oh # No. of printable columns
if np <= 0:
return
return # Can't clip a glyph: discard
else:
self._newline()
self.glyph = glyph
self.char_height = char_height
self.char_width = char_width
self.clip_width = char_width if np is None else np
# Method using blitting. Efficient rendering for monochrome displays.
# Tested on SSD1306. Invert is for black-on-white rendering.
def _printchar(self, char, invert=False, recurse=False):
@ -238,8 +237,8 @@ class Writer():
buf = bytearray(self.glyph)
if invert:
for i, v in enumerate(buf):
buf[i] = 0xFF & ~ v
fbc = framebuf.FrameBuffer(buf, self.clip_width, self.char_height, self.map)
buf[i] = 0xFF & ~v
fbc = framebuf.FrameBuffer(buf, self.char_width, self.char_height, self.map)
self.device.blit(fbc, s.text_col, s.text_row)
s.text_col += self.char_width
self.cpos += 1
@ -252,26 +251,24 @@ class Writer():
def setcolor(self, *_):
return self.fgcolor, self.bgcolor
# Writer for colour displays.
class CWriter(Writer):
@staticmethod
def create_color(ssd, idx, r, g, b):
c = ssd.rgb(r, g, b)
if not hasattr(ssd, 'lut'):
if not hasattr(ssd, "lut"):
return c
if not 0 <= idx <= 15:
raise ValueError('Color nos must be 0..15')
raise ValueError("Color nos must be 0..15")
x = idx << 1
ssd.lut[x] = c & 0xff
ssd.lut[x] = c & 0xFF
ssd.lut[x + 1] = c >> 8
return idx
def __init__(self, device, font, fgcolor=None, bgcolor=None, verbose=True):
if not hasattr(device, 'palette'):
raise OSError('Incompatible device driver.')
if implementation[1] < (1, 17, 0):
raise OSError('Firmware must be >= 1.17.')
if not hasattr(device, "palette"):
raise OSError("Incompatible device driver.")
super().__init__(device, font, verbose)
if bgcolor is not None: # Assume monochrome.
@ -287,7 +284,7 @@ class CWriter(Writer):
if self.glyph is None:
return # All done
buf = bytearray_at(addressof(self.glyph), len(self.glyph))
fbc = framebuf.FrameBuffer(buf, self.clip_width, self.char_height, self.map)
fbc = framebuf.FrameBuffer(buf, self.char_width, self.char_height, self.map)
palette = self.device.palette
palette.bg(self.fgcolor if invert else self.bgcolor)
palette.fg(self.bgcolor if invert else self.fgcolor)