]> Repositories - hackapet/Adafruit_Blinka_Displayio.git/blobdiff - displayio/tilegrid.py
Merge pull request #43 from FoamyGuy/scaling_fix
[hackapet/Adafruit_Blinka_Displayio.git] / displayio / tilegrid.py
index 861384e3cbee38559b1d25e65421179082a4fe96..58062531d98a2cf649ea16f471d717c87464fd67 100644 (file)
@@ -99,10 +99,14 @@ class TileGrid:
         self._flip_y = False
         self._top_left_x = 0
         self._top_left_y = 0
-        if tile_width is None:
+        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
@@ -198,82 +202,110 @@ class TileGrid:
         return pixel_value
 
     def _apply_palette(self, image):
-        if isinstance(self._pixel_shader, Palette):
-            image.putpalette(
-                self._pixel_shader._get_palette()
-            )  # pylint: disable=protected-access
-        if isinstance(self._pixel_shader, ColorConverter):
-            # This will be needed for eInks, grayscale, and monochrome displays
-            pass
+        image.putpalette(
+            self._pixel_shader._get_palette()  # pylint: disable=protected-access
+        )
 
     def _add_alpha(self, image):
-        if isinstance(self._pixel_shader, Palette):
-            alpha = self._bitmap._image.copy().convert(
-                "P"
-            )  # pylint: disable=protected-access
-            alpha.putpalette(
-                self._pixel_shader._get_alpha_palette()
-            )  # pylint: disable=protected-access
-            image.putalpha(alpha.convert("L"))
-
-    # pylint: disable=too-many-locals
+        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,too-many-statements
     def _fill_area(self, buffer):
         """Draw onto the image"""
         if self._hidden:
             return
 
-        image = Image.new(
-            "RGBA",
-            (self._width * self._tile_width, self._height * self._tile_height),
-            (0, 0, 0, 0),
-        )
+        if self._bitmap.width <= 0 or self._bitmap.height <= 0:
+            return
 
-        tile_count_x = self._bitmap.width // self._tile_width
+        # Copy class variables to local variables in case something changes
         x = self._x
         y = self._y
+        width = self._width
+        height = self._height
+        tile_width = self._tile_width
+        tile_height = self._tile_height
+        bitmap_width = self._bitmap.width
+        pixel_width = self._pixel_width
+        pixel_height = self._pixel_height
+        tiles = self._tiles
+        absolute_transform = self._absolute_transform
+        pixel_shader = self._pixel_shader
+        bitmap = self._bitmap
+        tiles = self._tiles
+
+        tile_count_x = bitmap_width // tile_width
+
+        image = Image.new(
+            "RGBA", (width * tile_width, height * tile_height), (0, 0, 0, 0),
+        )
 
-        for tile_x in range(self._width):
-            for tile_y in range(self._height):
-                tile_index = self._tiles[tile_y * self._width + tile_x]
+        for tile_x in range(width):
+            for tile_y in range(height):
+                tile_index = tiles[tile_y * width + tile_x]
                 tile_index_x = tile_index % tile_count_x
                 tile_index_y = tile_index // tile_count_x
-                tile_image = self._bitmap._image.copy().convert(
-                    "P"
-                )  # pylint: disable=protected-access
-                self._apply_palette(tile_image)
-                tile_image = tile_image.convert("RGBA")
-                self._add_alpha(tile_image)
+                tile_image = bitmap._image  # pylint: disable=protected-access
+                if isinstance(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(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,
-                    ),
+                    dest=(tile_x * tile_width, tile_y * tile_height),
+                    source=(tile_index_x * tile_width, tile_index_y * tile_height,),
                 )
 
-        if self._absolute_transform is not None:
-            if self._absolute_transform.scale > 1:
+        if absolute_transform is not None:
+            if absolute_transform.scale > 1:
                 image = image.resize(
                     (
-                        self._pixel_width * self._absolute_transform.scale,
-                        self._pixel_height * self._absolute_transform.scale,
+                        pixel_width * absolute_transform.scale,
+                        pixel_height * absolute_transform.scale,
                     ),
                     resample=Image.NEAREST,
                 )
-            if self._absolute_transform.mirror_x:
+            if absolute_transform.mirror_x:
                 image = image.transpose(Image.FLIP_LEFT_RIGHT)
-            if self._absolute_transform.mirror_y:
+            if absolute_transform.mirror_y:
                 image = image.transpose(Image.FLIP_TOP_BOTTOM)
-            if self._absolute_transform.transpose_xy:
+            if absolute_transform.transpose_xy:
                 image = image.transpose(Image.TRANSPOSE)
-            x *= self._absolute_transform.dx
-            y *= self._absolute_transform.dy
-            x += self._absolute_transform.x
-            y += self._absolute_transform.y
-        buffer.alpha_composite(image, (x, y))
+            x *= absolute_transform.dx
+            y *= absolute_transform.dy
+            x += absolute_transform.x
+            y += absolute_transform.y
+
+        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
+    # pylint: enable=too-many-locals,too-many-branches
 
     @property
     def hidden(self):