toggle cutoff line only in quick preview

web_backend.py

@@ -547,15 +547,18 @@ def start_job(kind, worker, owner=None, params=None, remember_user_task=True):
     return get_job(job_id)
 
 
-def make_preview(input_dir, angle_degrees):
+def make_preview(input_dir, angle_degrees, show_cutoff_line=True):
     volume = load_dicom_volume(input_dir)
     before = crop_head_neck(sagittal_mip(volume))
-    after = preview_deform_2d(before, float(angle_degrees))
-    after = draw_cutoff_line(after, volume.shape[0])
+    before_display = draw_cutoff_line(before, volume.shape[0]) if show_cutoff_line else before
+    after = preview_deform_2d(before_display, float(angle_degrees))
+
+    canvas_image = Image.new("RGB", (1440, 520), (0, 0, 0))
+    canvas_image.paste(fit_image(before_display, 700, 520), (0, 0))
+    canvas_image.paste(fit_image(after, 700, 520), (740, 0))
 
     canvas = BytesIO()
-    preview = fit_image(after, 720, 520)
-    preview.save(canvas, format="PNG")
+    canvas_image.save(canvas, format="PNG")
     encoded = base64.b64encode(canvas.getvalue()).decode("ascii")
     return {
         "image": f"data:image/png;base64,{encoded}",
@@ -721,7 +724,13 @@ class Handler(BaseHTTPRequestHandler):
 
             body = self.read_json()
             if parsed.path == "/api/preview":
-                self.send_json(make_preview(body["inputDir"], body.get("angleDegrees", 12)))
+                self.send_json(
+                    make_preview(
+                        body["inputDir"],
+                        body.get("angleDegrees", 12),
+                        bool(body.get("showCutoffLine", True)),
+                    )
+                )
                 return
 
             if parsed.path == "/api/deformation/package":