Merge pull request #141 from adafruit/tannewt-patch-1

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

diff --git a/displayio/_ondiskbitmap.py b/displayio/_ondiskbitmap.py
index 4a638a9b6eb6060e1543d10916e8b3b4b63e82ea..654a312a199b999b22231da11f5b1f262b0bbb04 100644 (file)
--- a/displayio/_ondiskbitmap.py
+++ b/displayio/_ondiskbitmap.py
@@ -35,9 +35,6 @@ class OnDiskBitmap:
     load times. These load times may result in frame tearing where only part of the image is
     visible.
 
     load times. These load times may result in frame tearing where only part of the image is
     visible.
 

-    It's easiest to use on a board with a built in display such as the `Hallowing M0 Express
-    <https://www.adafruit.com/product/3900>`_.
-

     .. code-block:: Python
 
         import board
     .. code-block:: Python
 
         import board


@@ -48,7 +45,7 @@ class OnDiskBitmap:
         board.DISPLAY.auto_brightness = False
         board.DISPLAY.brightness = 0
         splash = displayio.Group()
         board.DISPLAY.auto_brightness = False
         board.DISPLAY.brightness = 0
         splash = displayio.Group()

-        board.DISPLAY.show(splash)
+        board.DISPLAY.root_group = splash

 
         odb = displayio.OnDiskBitmap(\'/sample.bmp\')
         face = displayio.TileGrid(odb, pixel_shader=odb.pixel_shader)
 
         odb = displayio.OnDiskBitmap(\'/sample.bmp\')
         face = displayio.TileGrid(odb, pixel_shader=odb.pixel_shader)


@@ -234,27 +231,30 @@ class OnDiskBitmap:
 
         self._file.seek(location)
 
 
         self._file.seek(location)
 

-        pixel_data = memoryview(self._file.read(4)).cast(
-            "I"
-        )  # cast as unsigned 32-bit int
-        pixel_data = pixel_data[0]  # We only need a single 32-bit uint
-        if bytes_per_pixel == 1:
-            offset = (x % pixels_per_byte) * self._bits_per_pixel
-            mask = (1 << self._bits_per_pixel) - 1
-            return (pixel_data >> ((8 - self._bits_per_pixel) - offset)) & mask
-        if bytes_per_pixel == 2:
-            if self._g_bitmask == 0x07E0:  # 565
-                red = (pixel_data & self._r_bitmask) >> 11
-                green = (pixel_data & self._g_bitmask) >> 5
-                blue = pixel_data & self._b_bitmask
-            else:  # 555
-                red = (pixel_data & self._r_bitmask) >> 10
-                green = (pixel_data & self._g_bitmask) >> 4
-                blue = pixel_data & self._b_bitmask
-            return red << 19 | green << 10 | blue << 3
-        if bytes_per_pixel == 4 and self._bitfield_compressed:
-            return pixel_data & 0x00FFFFFF
-        return pixel_data
+        pixel_data = self._file.read(bytes_per_pixel)
+        if len(pixel_data) == bytes_per_pixel:
+            if bytes_per_pixel == 1:
+                offset = (x % pixels_per_byte) * self._bits_per_pixel
+                mask = (1 << self._bits_per_pixel) - 1
+                return (pixel_data[0] >> ((8 - self._bits_per_pixel) - offset)) & mask
+            if bytes_per_pixel == 2:
+                pixel_data = pixel_data[0] | pixel_data[1] << 8
+                if self._g_bitmask == 0x07E0:  # 565
+                    red = (pixel_data & self._r_bitmask) >> 11
+                    green = (pixel_data & self._g_bitmask) >> 5
+                    blue = pixel_data & self._b_bitmask
+                else:  # 555
+                    red = (pixel_data & self._r_bitmask) >> 10
+                    green = (pixel_data & self._g_bitmask) >> 4
+                    blue = pixel_data & self._b_bitmask
+                return red << 19 | green << 10 | blue << 3
+            if bytes_per_pixel == 4 and self._bitfield_compressed:
+                return pixel_data[0] | pixel_data[1] << 8 | pixel_data[2] << 16
+            pixel = pixel_data[0] | pixel_data[1] << 8 | pixel_data[2] << 16
+            if bytes_per_pixel == 4:
+                pixel |= pixel_data[3] << 24
+            return pixel
+        return 0

 
     def _finish_refresh(self) -> None:
         pass
 
     def _finish_refresh(self) -> None:
         pass