Sight groups, DM reveal areas (cones), client-side image shrink for map upload

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HJhXuLD2Z6hv3Wqeq9UL9K

backend/app/vision.py

@@ -11,8 +11,9 @@ from PIL import Image, ImageDraw
 EPS = 1e-5
 
 
-def polygon(origin, segs, w, h, radius=0.0):
-    """Points of the area visible from origin. segs: [(x1, y1, x2, y2)] that block sight; radius 0 means unlimited."""
+def polygon(origin, segs, w, h, radius=0.0, sector=None):
+    """Points of the area visible from origin. segs: [(x1, y1, x2, y2)] that block sight; radius 0 means unlimited.
+    sector = (direction, half angle) in radians limits the view to a cone."""
     ox, oy = origin
     border = [(0, 0, w, 0), (w, 0, w, h), (w, h, 0, h), (0, h, 0, 0)]
     if radius:
@@ -34,7 +35,13 @@ def polygon(origin, segs, w, h, radius=0.0):
             angles += (a - EPS, a, a + EPS)
     if radius:
         angles += [i * (2 * math.pi / 120) for i in range(120)]
-    angles.sort()
+    if sector:
+        d, half = sector
+        rel = [(a - d + math.pi) % (2 * math.pi) - math.pi for a in angles]
+        rel = [a for a in rel if abs(a) <= half] + [-half, half] + [-half + i * (2 * half / 48) for i in range(49)]
+        angles = [d + a for a in sorted(rel)]
+    else:
+        angles.sort()
     pts = []
     for a in angles:
         dx, dy = math.cos(a), math.sin(a)
@@ -54,7 +61,7 @@ def polygon(origin, segs, w, h, radius=0.0):
         if best == float("inf"):
             continue
         pts.append((ox + dx * best, oy + dy * best))
-    return pts
+    return [(ox, oy)] + pts if sector else pts
 
 
 def inside(pt, poly) -> bool:
@@ -112,19 +119,26 @@ def source(path):
     return im
 
 
-def cut(path, poly, key):
+def inside_any(pt, polys) -> bool:
+    return any(inside(pt, p) for p in polys)
+
+
+def cut(path, polys, key):
     """The part of the image inside the polygon (everything else black), cropped to its bounding box.
     Returns (webp bytes, (x, y, w, h))."""
     hit = _cuts.fetch(key)
     if hit:
         return hit
     im = source(path)
-    xs, ys = [p[0] for p in poly], [p[1] for p in poly]
+    xs, ys = [p[0] for poly in polys for p in poly], [p[1] for poly in polys for p in poly]
     x0, y0 = max(0, int(math.floor(min(xs)))), max(0, int(math.floor(min(ys))))
     x1, y1 = min(im.width, int(math.ceil(max(xs)))), min(im.height, int(math.ceil(max(ys))))
     w, h = max(1, x1 - x0), max(1, y1 - y0)
     mask = Image.new("L", (w, h), 0)
-    ImageDraw.Draw(mask).polygon([(x - x0, y - y0) for x, y in poly], fill=255)
+    draw = ImageDraw.Draw(mask)
+    for poly in polys:
+        if len(poly) > 2:
+            draw.polygon([(x - x0, y - y0) for x, y in poly], fill=255)
     piece = Image.composite(im.crop((x0, y0, x0 + w, y0 + h)), Image.new("RGB", (w, h), (0, 0, 0)), mask)
     out = io.BytesIO()
     piece.save(out, "WEBP", quality=82, method=1)