Fix link in Readme

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

diff --git a/displayio/tilegrid.py b/displayio/tilegrid.py
index c68fe9d370fca1e83cd5a7badbc833e8c03c5555..2c815a4f9280e92558ffab6d70e4373327ab9076 100644 (file)
--- a/displayio/tilegrid.py
+++ b/displayio/tilegrid.py
@@ -82,9 +82,13 @@ class TileGrid:
         bitmap_width = bitmap.width
         bitmap_height = bitmap.height
 
-        if not isinstance(pixel_shader, (ColorConverter, Palette)):
+        if pixel_shader is not None and not isinstance(
+            pixel_shader, (ColorConverter, Palette)
+        ):
             raise ValueError("Unsupported Pixel Shader type")
         self._pixel_shader = pixel_shader
+        if isinstance(self._pixel_shader, ColorConverter):
+            self._pixel_shader._rgba = True  # pylint: disable=protected-access
         self._hidden = False
         self._x = x
         self._y = y
@@ -93,10 +97,16 @@ class TileGrid:
         self._transpose_xy = False
         self._flip_x = False
         self._flip_y = False
-        if tile_width is None:
+        self._top_left_x = 0
+        self._top_left_y = 0
+        if tile_width is None or tile_width == 0:
             tile_width = bitmap_width
-        if tile_height is None:
+        if tile_height is None or tile_width == 0:
             tile_height = bitmap_height
+        if tile_width < 1:
+            tile_width = 1
+        if tile_height < 1:
+            tile_height = 1
         if bitmap_width % tile_width != 0:
             raise ValueError("Tile width must exactly divide bitmap width")
         self._tile_width = tile_width
@@ -184,12 +194,36 @@ class TileGrid:
                     self._current_area.y1,
                 )
 
-    # pylint: disable=too-many-locals
+    def _shade(self, pixel_value):
+        if isinstance(self._pixel_shader, Palette):
+            return self._pixel_shader[pixel_value]["rgba"]
+        if isinstance(self._pixel_shader, ColorConverter):
+            return self._pixel_shader.convert(pixel_value)
+        return pixel_value
+
+    def _apply_palette(self, image):
+        image.putpalette(
+            self._pixel_shader._get_palette()  # pylint: disable=protected-access
+        )
+
+    def _add_alpha(self, image):
+        alpha = self._bitmap._image.copy().convert(  # pylint: disable=protected-access
+            "P"
+        )
+        alpha.putpalette(
+            self._pixel_shader._get_alpha_palette()  # pylint: disable=protected-access
+        )
+        image.putalpha(alpha.convert("L"))
+
+    # pylint: disable=too-many-locals,too-many-branches
     def _fill_area(self, buffer):
         """Draw onto the image"""
         if self._hidden:
             return
 
+        if self._bitmap.width <= 0 or self._bitmap.height <= 0:
+            return
+
         image = Image.new(
             "RGBA",
             (self._width * self._tile_width, self._height * self._tile_height),
@@ -200,22 +234,29 @@ class TileGrid:
         x = self._x
         y = self._y
 
-        for tile_x in range(0, self._width):
-            for tile_y in range(0, self._height):
+        for tile_x in range(self._width):
+            for tile_y in range(self._height):
                 tile_index = self._tiles[tile_y * self._width + tile_x]
                 tile_index_x = tile_index % tile_count_x
                 tile_index_y = tile_index // tile_count_x
-                for pixel_x in range(self._tile_width):
-                    for pixel_y in range(self._tile_height):
-                        image_x = tile_x * self._tile_width + pixel_x
-                        image_y = tile_y * self._tile_height + pixel_y
-                        bitmap_x = tile_index_x * self._tile_width + pixel_x
-                        bitmap_y = tile_index_y * self._tile_height + pixel_y
-                        pixel_color = self._pixel_shader[
-                            self._bitmap[bitmap_x, bitmap_y]
-                        ]
-                        if not pixel_color["transparent"]:
-                            image.putpixel((image_x, image_y), pixel_color["rgb888"])
+                tile_image = self._bitmap._image  # pylint: disable=protected-access
+                if isinstance(self._pixel_shader, Palette):
+                    tile_image = tile_image.copy().convert("P")
+                    self._apply_palette(tile_image)
+                    tile_image = tile_image.convert("RGBA")
+                    self._add_alpha(tile_image)
+                elif isinstance(self._pixel_shader, ColorConverter):
+                    # This will be needed for eInks, grayscale, and monochrome displays
+                    pass
+                image.alpha_composite(
+                    tile_image,
+                    dest=(tile_x * self._tile_width, tile_y * self._tile_height),
+                    source=(
+                        tile_index_x * self._tile_width,
+                        tile_index_y * self._tile_height,
+                    ),
+                )
+
         if self._absolute_transform is not None:
             if self._absolute_transform.scale > 1:
                 image = image.resize(
@@ -235,9 +276,27 @@ class TileGrid:
             y *= self._absolute_transform.dy
             x += self._absolute_transform.x
             y += self._absolute_transform.y
-        buffer.alpha_composite(image, (x, y))
 
-    # pylint: enable=too-many-locals
+        source_x = source_y = 0
+        if x < 0:
+            source_x = round(0 - x)
+            x = 0
+        if y < 0:
+            source_y = round(0 - y)
+            y = 0
+
+        x = round(x)
+        y = round(y)
+
+        if (
+            x <= buffer.width
+            and y <= buffer.height
+            and source_x <= image.width
+            and source_y <= image.height
+        ):
+            buffer.alpha_composite(image, (x, y), source=(source_x, source_y))
+
+    # pylint: enable=too-many-locals,too-many-branches
 
     @property
     def hidden(self):