update box_iou_rotated

Author: qiank10

Diff for: detectron2/layers/csrc/box_iou_rotated/box_iou_rotated_utils.h

@@ -86,6 +86,13 @@ HOST_DEVICE_INLINE int get_intersection_points(
     vec2[i] = pts2[(i + 1) % 4] - pts2[i];
   }
 
+  // When computing the intersection area, it doesn't hurt if we have
+  // more (duplicated/approximate) intersections/vertices than needed,
+  // while it can cause drastic difference if we miss an intersection/vertex.
+  // Therefore, we add an epsilon to relax the comparisons between
+  // the float point numbers that decide the intersection points.
+  double EPS = 1e-5;
+
   // Line test - test all line combos for intersection
   int num = 0; // number of intersections
   for (int i = 0; i < 4; i++) {
@@ -103,7 +110,7 @@ HOST_DEVICE_INLINE int get_intersection_points(
       T t1 = cross_2d<T>(vec2[j], vec12) / det;
       T t2 = cross_2d<T>(vec1[i], vec12) / det;
 
-      if (t1 >= 0.0f && t1 <= 1.0f && t2 >= 0.0f && t2 <= 1.0f) {
+      if (t1 > -EPS && t1 < 1.0f + EPS && t2 > -EPS && t2 < 1.0f + EPS) {
         intersections[num++] = pts1[i] + vec1[i] * t1;
       }
     }
@@ -125,8 +132,8 @@ HOST_DEVICE_INLINE int get_intersection_points(
       auto APdotAB = dot_2d<T>(AP, AB);
       auto APdotAD = -dot_2d<T>(AP, DA);
 
-      if ((APdotAB >= 0) && (APdotAD >= 0) && (APdotAB <= ABdotAB) &&
-          (APdotAD <= ADdotAD)) {
+      if ((APdotAB > -EPS) && (APdotAD > -EPS) && (APdotAB < ABdotAB + EPS) &&
+          (APdotAD < ADdotAD + EPS)) {
         intersections[num++] = pts1[i];
       }
     }
@@ -144,8 +151,8 @@ HOST_DEVICE_INLINE int get_intersection_points(
       auto APdotAB = dot_2d<T>(AP, AB);
       auto APdotAD = -dot_2d<T>(AP, DA);
 
-      if ((APdotAB >= 0) && (APdotAD >= 0) && (APdotAB <= ABdotAB) &&
-          (APdotAD <= ADdotAD)) {
+      if ((APdotAB > -EPS) && (APdotAD > -EPS) && (APdotAB < ABdotAB + EPS) &&
+          (APdotAD < ADdotAD + EPS)) {
         intersections[num++] = pts2[i];
       }
     }

Diff for: detectron2/modeling/poolers.py

@@ -168,7 +168,7 @@ def __init__(
         assert (
             len(scales) == self.max_level - self.min_level + 1
         ), "[ROIPooler] Sizes of input featuremaps do not form a pyramid!"
-        assert 0 < self.min_level and self.min_level <= self.max_level
+        assert 0 <= self.min_level and self.min_level <= self.max_level
         if len(scales) > 1:
             # When there is only one feature map, canonical_level is redundant and we should not
             # require it to be a sensible value. Therefore we skip this assertion