adding a displayio example

.gitignore

@@ -9,6 +9,5 @@ bundles
 .eggs
 dist
 **/*.egg-info
-*.bdf
 *.pcf
 *.ttf

examples/bitmap_font_displayio_simpletest.py

@@ -0,0 +1,65 @@
+"""
+This example runs on PyPortal, or any Circuit Python device
+with a built-in screen that is at least 320x240 pixels.
+
+It will use adafruit_bitmap_font to load a font and fill a
+bitmap with pixels matching glyphs from a given String
+"""
+
+
+import board
+from adafruit_bitmap_font import bitmap_font  # pylint: disable=wrong-import-position
+import displayio
+
+font = bitmap_font.load_font("fonts/Arial-16.bdf")
+
+bitmap = displayio.Bitmap(320, 240, 2)
+
+palette = displayio.Palette(2)
+
+palette[0] = 0x000000
+palette[1] = 0xFFFFFF
+
+_, height, _, dy = font.get_bounding_box()
+for y in range(height):
+    pixels = []
+    for c in "Adafruit CircuitPython":
+        glyph = font.get_glyph(ord(c))
+        if not glyph:
+            continue
+        glyph_y = y + (glyph.height - (height + dy)) + glyph.dy
+
+        if 0 <= glyph_y < glyph.height:
+            for i in range(glyph.width):
+                value = glyph.bitmap[i, glyph_y]
+                pixel = 0
+                if value > 0:
+                    pixel = 1
+                pixels.append(pixel)
+        else:
+            # empty section for this glyph
+            for i in range(glyph.width):
+                pixels.append(0)
+
+        # one space between glyph
+        pixels.append(0)
+
+    if pixels:
+        for x, pixel in enumerate(pixels):
+            bitmap[x, y] = pixel
+
+# Create a TileGrid to hold the bitmap
+tile_grid = displayio.TileGrid(bitmap, pixel_shader=palette)
+
+# Create a Group to hold the TileGrid
+group = displayio.Group()
+
+group.x = 20
+# Add the TileGrid to the Group
+group.append(tile_grid)
+
+# Add the Group to the Display
+board.DISPLAY.show(group)
+
+while True:
+    pass