Optimize OnDiskBitMap a bit

[hackapet/Adafruit_Blinka_Displayio.git] / displayio / _tilegrid.py

diff --git a/displayio/_tilegrid.py b/displayio/_tilegrid.py
index 6705601681d16bae4a6ad9ce820847d44aa478f1..5abfad44296ea7441930e5bd0b372f88888cdf4a 100644 (file)
--- a/displayio/_tilegrid.py
+++ b/displayio/_tilegrid.py
@@ -392,7 +392,7 @@ class TileGrid:
                             # even if we multiply it back out
                             offset = (
                                 col * pixels_per_byte
-                                + (row // pixels_per_byte) * width
+                                + (row // pixels_per_byte) * pixels_per_byte * width
                                 + (row % pixels_per_byte)
                             )
                         shift = (offset % pixels_per_byte) * colorspace.depth
@@ -400,6 +400,7 @@ class TileGrid:
                             # Reverse the shift by subtracting it from the leftmost shift
                             shift = (pixels_per_byte - 1) * colorspace.depth - shift
                         buffer[offset // pixels_per_byte] |= output_pixel.pixel << shift
+
         return full_coverage
 
     def _finish_refresh(self):