实现 MonoBitmap.scale()

src/pixel_font_knife/mono_bitmap.py

@@ -70,6 +70,19 @@ def resize(self, left: int = 0, right: int = 0, top: int = 0, bottom: int = 0) -
             bitmap.append(bitmap_row)
         return bitmap
 
+    def scale(self, scale_x: float = 1, scale_y: float = 1) -> 'MonoBitmap':
+        bitmap = MonoBitmap()
+        bitmap.width = int(self.width * scale_x)
+        bitmap.height = int(self.height * scale_y)
+        for y in range(bitmap.height):
+            sy = int(y / scale_y)
+            bitmap_row = []
+            for x in range(bitmap.width):
+                sx = int(x / scale_x)
+                bitmap_row.append(self[sy][sx])
+            bitmap.append(bitmap_row)
+        return bitmap
+
     def draw(self, white: str = '  ', black: str = '██', end: str | None = None) -> str:
         text = StringIO()
         for bitmap_row in self:

tests/test_mono_bitmap.py

@@ -104,6 +104,17 @@ def test_resize():
     ])
 
 
+def test_scale(glyphs_dir: Path):
+    for file_path in glyphs_dir.joinpath('black').iterdir():
+        x1_bitmap = MonoBitmap.load_png(file_path)
+        x3_bitmap = MonoBitmap.load_png(glyphs_dir.joinpath('x3', file_path.name))
+        x1_5_bitmap = MonoBitmap.load_png(glyphs_dir.joinpath('x1.5', file_path.name))
+        assert x1_bitmap.scale(3, 3) == x3_bitmap
+        assert x1_bitmap.scale(1.5, 1.5) == x1_5_bitmap
+        assert x3_bitmap.scale(1 / 3, 1 / 3) == x1_bitmap
+        assert x3_bitmap.scale(0.5, 0.5) == x1_5_bitmap
+
+
 def test_draw():
     bitmap = MonoBitmap([
         [1, 1, 0, 0],