render: support 90-deg rotation; default to 90 CCW so panel works in portrait

src/inky_impression/render.py

@@ -31,13 +31,24 @@ def screenshot_url(url: str, width: int, height: int, out: pathlib.Path) -> None
     )
 
 
-def show_url(url: str, *, saturation: float = 0.5) -> None:
+def show_url(url: str, *, saturation: float = 0.5, rotate: int = 90) -> None:
+    """Screenshot `url` and push to the Inky.
+
+    `rotate` is degrees CCW applied to the rendered image before it's sent to
+    the panel (0/90/180/270). 90 and 270 swap the viewport to portrait so the
+    web page is laid out for the rotated orientation, not letterboxed.
+    """
     inky = auto(ask_user=False, verbose=False)
-    w, h = inky.resolution
+    panel_w, panel_h = inky.resolution
+    rotate = rotate % 360
+    shot_w, shot_h = (panel_h, panel_w) if rotate in (90, 270) else (panel_w, panel_h)
     with tempfile.TemporaryDirectory() as tmp:
         out = pathlib.Path(tmp) / "screen.png"
-        screenshot_url(url, w, h, out)
+        screenshot_url(url, shot_w, shot_h, out)
-        img = Image.open(out).convert("RGB").resize((w, h))
+        img = Image.open(out).convert("RGB")
+        if rotate:
+            img = img.rotate(rotate, expand=True)
+        img = img.resize((panel_w, panel_h))
         try:
             inky.set_image(img, saturation=saturation)
         except TypeError: