feat: add collisions

src/utils.py

@@ -1,5 +1,34 @@
 import os
 from pathlib import Path
 
+from src.vec import Vec
+
 
 ROOT = Path(os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir)))
+
+
+def orientation(a: Vec, b: Vec, c: Vec) -> float:
+    return (b - a).cross(c - a)
+
+
+def segments_intersect(a1: Vec, a2: Vec, b1: Vec, b2: Vec) -> bool:
+    o1 = orientation(a1, a2, b1)
+    o2 = orientation(a1, a2, b2)
+    o3 = orientation(b1, b2, a1)
+    o4 = orientation(b1, b2, a2)
+
+    # General case: segments straddle each other
+    if (o1 * o2 < 0) and (o3 * o4 < 0):
+        return True
+
+    # Special cases: Collinear overlaps
+    if o1 == 0 and b1.within(a1, a2):
+        return True
+    if o2 == 0 and b2.within(a1, a2):
+        return True
+    if o3 == 0 and a1.within(b1, b2):
+        return True
+    if o4 == 0 and a2.within(b1, b2):
+        return True
+
+    return False