Merge pull request #1938 from itzpr3d4t0r/rect_clip_simplification+

simplified pg_rect_clip

Author: ankith26

src_c/rect.c

@@ -1105,46 +1105,16 @@ pg_rect_clip(pgRectObject *self, PyObject *args)
         return RAISE(PyExc_TypeError, "Argument must be rect style object");
     }
 
-    /* Left */
-    if ((A->x >= B->x) && (A->x < (B->x + B->w))) {
-        x = A->x;
-    }
-    else if ((B->x >= A->x) && (B->x < (A->x + A->w)))
-        x = B->x;
-    else
-        goto nointersect;
-
-    /* Right */
-    if (((A->x + A->w) > B->x) && ((A->x + A->w) <= (B->x + B->w))) {
-        w = (A->x + A->w) - x;
-    }
-    else if (((B->x + B->w) > A->x) && ((B->x + B->w) <= (A->x + A->w)))
-        w = (B->x + B->w) - x;
-    else
-        goto nointersect;
+    x = MAX(A->x, B->x);
+    y = MAX(A->y, B->y);
+    w = MIN(A->x + A->w, B->x + B->w) - x;
+    h = MIN(A->y + A->h, B->y + B->h) - y;
 
-    /* Top */
-    if ((A->y >= B->y) && (A->y < (B->y + B->h))) {
-        y = A->y;
+    if (w <= 0 || h <= 0) {
+        return _pg_rect_subtype_new4(Py_TYPE(self), A->x, A->y, 0, 0);
     }
-    else if ((B->y >= A->y) && (B->y < (A->y + A->h)))
-        y = B->y;
-    else
-        goto nointersect;
-
-    /* Bottom */
-    if (((A->y + A->h) > B->y) && ((A->y + A->h) <= (B->y + B->h))) {
-        h = (A->y + A->h) - y;
-    }
-    else if (((B->y + B->h) > A->y) && ((B->y + B->h) <= (A->y + A->h)))
-        h = (B->y + B->h) - y;
-    else
-        goto nointersect;
 
     return _pg_rect_subtype_new4(Py_TYPE(self), x, y, w, h);
-
-nointersect:
-    return _pg_rect_subtype_new4(Py_TYPE(self), A->x, A->y, 0, 0);
 }
 
 /* clipline() - crops the given line within the rect

test/rect_test.py

@@ -847,6 +847,10 @@ def test_clip(self):
         self.assertEqual(
             r1, r1.clip(Rect(r1)), "r1 does not clip an identical rect to itself"
         )
+        self.assertEqual(Rect(1, 2, 0, 0), r1.clip(Rect(3, 0, 2, 2)))
+        self.assertEqual(Rect(1, 2, 0, 0), r1.clip(Rect(3, 8, 2, 2)))
+        self.assertEqual(Rect(1, 2, 0, 0), r1.clip(Rect(-2, 8, 2, 2)))
+        self.assertEqual(Rect(1, 2, 0, 0), r1.clip(Rect(-2, 0, 2, 2)))
 
     def test_clipline(self):
         """Ensures clipline handles four int parameters.