Smaller, faster writer.py. Requires fw V1.17 or later.

README.md

@@ -60,8 +60,9 @@ Code has been tested on ESP32, Pi Pico and Pyboard. The API shuld be stable.
 Code is new and issues are likely: please report any found. The project is
 under development so check for updates.
 
-A recent firmware update [PR7682](https://github.com/micropython/micropython/pull/7682)
+Firmware V1.17 has provided a major boost to text rendering speed on color
-has provided a major boost to text rendering speed on color displays. See
+display. V1.17 or later is now a requirement for color displays, although
+there is a workround if it's impossible to upgrade. See
 [section 1.8](./README.md#18-performance-and-hardware-notes) for details.
 
 # 0. Contents
@@ -127,6 +128,7 @@ has provided a major boost to text rendering speed on color displays. See
       23.3.1 [Class Curve](./README.md#2331-class-curve)  
       23.3.2 [Class PolarCurve](./README.md#2332-class-polarcurve)  
  23.4 [Class TSequence](./README.md#234-class-tsequence) Plotting realtime, time sequential data.  
+24. [Old firmware](./README.md#24-old-firmware) For users of color displays who can't run current firmware.  
 [Appendix 1 Application design](./README.md#appendix-1-application-design) Tab order, button layout, encoder interface, use of graphics primitives  
 
 # 1. Basic concepts
@@ -414,21 +416,20 @@ RAM usage. A smaller display or a Pyboard D would offer more headroom.
 
 #### A performance boost
 
-As of Aug 2021 a firmware update
+A firmware change in V1.17 has enabled the code size to be reduced. It has also
-[PR7682](https://github.com/micropython/micropython/pull/7682) means that color
+accelerated text rendering on color displays. Use of color displays now
-displays can benefit from a substantial performance boost in rendering text. To
+requires firmware V1.17 or later. Existing users should update the display
-take advantage of this, firmware should be dated after 26 Aug 21. The display
+driver and GUI core files and should ensure that the new file
-driver and GUI core files should be updated. Ensure that the new file 
+`drivers/boolpalette.py` exists.
-`drivers/boolpalette.py` exists on the target hardware.
 
 ###### [Contents](./README.md#0-contents)
 
 ## 1.9 Firmware and dependencies
 
-Firmware should be V1.15 or later. For fast text rendering a daily build or
+Users of color displays should ensure that firmware is V1.17 or later. If this
-a release build >= 1.17 should be used. The source tree includes all
+cannot be met, there is a [workround](./README.md#24-old-firmware). The source
-dependencies. These are listed to enable users to check for newer versions or
+tree includes all dependencies. These are listed to enable users to check for
-to read docs:
+newer versions or to read docs:
 
  * [writer.py](https://github.com/peterhinch/micropython-font-to-py/blob/master/writer/writer.py)
  Provides text rendering of Python font files.
@@ -2612,6 +2613,15 @@ class TSeq(Screen):
             await asyncio.sleep_ms(400)
             t += 1
 ```
+###### [Contents](./README.md#0-contents)
+
+# 24. Old firmware
+
+Current firmware is highly recommended. For users of color displays who cannot
+run V1.17 or later it is possible to run under V1.15+. This involves copying
+[this file](https://github.com/peterhinch/micropython-font-to-py/blob/master/writer/old_versions/writer_fw_compatible.py)
+to `gui/core/writer.py`. This uses Python code to render text if the firmware
+or driver are unable to support fast rendering.
 
 ###### [Contents](./README.md#0-contents)
 

gui/core/writer.py

@@ -1,6 +1,7 @@
 # writer.py Implements the Writer class.
 # Handles colour, word wrap and tab stops
 
+# V0.5.0 Sep 2021 Color now requires firmware >= 1.17.
 # V0.4.3 Aug 2021 Support for fast blit to color displays (PR7682).
 # V0.4.0 Jan 2021 Improved handling of word wrap and line clip. Upside-down
 # rendering no longer supported: delegate to device driver.
@@ -24,27 +25,9 @@ from uctypes import bytearray_at, addressof
 from sys import implementation
 import os
 
-__version__ = (0, 4, 3)
+__version__ = (0, 5, 0)
 
-def buildcheck(device):
+fast_mode = True  # Does nothing. Kept to avoid breaking code.
-    if not hasattr(device, 'palette'):
-        return False
-    i0, i1, _ = implementation[1]
-    if i0 > 1 or i1 > 16:
-        return True
-    # After release of V1.17 require that build. Until then check for date.
-    # TODO simplify this once V1.17 is released.
-    try:
-        datestring = os.uname()[3]
-        date = datestring.split(' on')[1]
-        date = date.lstrip()[:10]
-        idate = tuple([int(x) for x in date.split('-')])
-        return idate >= (2021, 8, 25)
-    except AttributeError:
-        return False
-
-
-fast_mode = False  # False for mono displays although actually these render fast
 
 class DisplayState():
     def __init__(self):
@@ -202,7 +185,7 @@ 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):
@@ -272,19 +255,20 @@ class CWriter(Writer):
 
 
     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.')
+
         super().__init__(device, font, verbose)
-        global fast_mode
-        fast_mode = buildcheck(device)
         if bgcolor is not None:  # Assume monochrome.
             self.bgcolor = bgcolor
         if fgcolor is not None:
             self.fgcolor = fgcolor
         self.def_bgcolor = self.bgcolor
         self.def_fgcolor = self.fgcolor
-        self._printchar = self._pchfast if fast_mode else self._pchslow
-        verbose and print('Render {} using fast mode'.format('is' if fast_mode else 'not'))
 
-    def _pchfast(self, char, invert=False, recurse=False):
+    def _printchar(self, char, invert=False, recurse=False):
         s = self._getstate()
         self._get_char(char, recurse)
         if self.glyph is None:
@@ -294,42 +278,10 @@ class CWriter(Writer):
         palette = self.device.palette
         palette.bg(self.fgcolor if invert else self.bgcolor)
         palette.fg(self.bgcolor if invert else self.fgcolor)
-
         self.device.blit(fbc, s.text_col, s.text_row, -1, palette)
         s.text_col += self.char_width
         self.cpos += 1
 
-    def _pchslow(self, char, invert=False, recurse=False):
-        s = self._getstate()
-        self._get_char(char, recurse)
-        if self.glyph is None:
-            return  # All done
-        char_height = self.char_height
-        char_width = self.char_width
-        clip_width = self.clip_width
-
-        div, mod = divmod(char_width, 8)
-        gbytes = div + 1 if mod else div  # No. of bytes per row of glyph
-        device = self.device
-        fgcolor = self.bgcolor if invert else self.fgcolor
-        bgcolor = self.fgcolor if invert else self.bgcolor
-        drow = s.text_row  # Destination row
-        wcol = s.text_col  # Destination column of character start
-        for srow in range(char_height):  # Source row
-            for scol in range(clip_width):  # Source column
-                # Destination column: add writer column
-                dcol = wcol + scol
-                gbyte, gbit = divmod(scol, 8)
-                if gbit == 0:  # Next glyph byte
-                    data = self.glyph[srow * gbytes + gbyte]
-                pixel = fgcolor if data & (1 << (7 - gbit)) else bgcolor
-                device.pixel(dcol, drow, pixel)
-            drow += 1
-            if drow >= self.screenheight or drow < 0:
-                break
-        s.text_col += char_width
-        self.cpos += 1
-
     def setcolor(self, fgcolor=None, bgcolor=None):
         if fgcolor is None and bgcolor is None:
             self.fgcolor = self.def_fgcolor