diff --git a/panda/src/putil/bitMask.I b/panda/src/putil/bitMask.I
index 4b737eec5d..993c35128a 100644
--- a/panda/src/putil/bitMask.I
+++ b/panda/src/putil/bitMask.I
@@ -400,46 +400,6 @@ set_word(WordType value) {
   _word = value;
 }
 
-////////////////////////////////////////////////////////////////////
-//     Function: BitMask::invert_in_place
-//       Access: Published
-//  Description: Inverts all the bits in the BitMask.  This is
-//               equivalent to mask = ~mask.
-////////////////////////////////////////////////////////////////////
-template<class WType, int nbits>
-INLINE void BitMask<WType, nbits>::
-invert_in_place() {
-  _word = ~_word;
-}
-
-////////////////////////////////////////////////////////////////////
-//     Function: BitMask::has_bits_in_common
-//       Access: Published
-//  Description: Returns true if this BitMask has any "one" bits in
-//               common with the other one, false otherwise.
-//
-//               This is equivalent to (mask & other) != 0, but may be
-//               faster.  (Actually, it should only be faster in the
-//               BitArray case, but this method is provided for the
-//               benefit of generic programming algorithms).
-////////////////////////////////////////////////////////////////////
-template<class WType, int nbits>
-INLINE bool BitMask<WType, nbits>::
-has_bits_in_common(const BitMask<WType, nbits> &other) const {
-  return (_word & other._word) != 0;
-}
-
-////////////////////////////////////////////////////////////////////
-//     Function: BitMask::clear
-//       Access: Published
-//  Description: Sets all the bits in the BitMask off.
-////////////////////////////////////////////////////////////////////
-template<class WType, int nbits>
-INLINE void BitMask<WType, nbits>::
-clear() {
-  _word = 0;
-}
-
 ////////////////////////////////////////////////////////////////////
 //     Function: BitMask::get_num_on_bits
 //       Access: Published
@@ -565,6 +525,46 @@ get_next_higher_different_bit(int low_bit) const {
   }
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: BitMask::invert_in_place
+//       Access: Published
+//  Description: Inverts all the bits in the BitMask.  This is
+//               equivalent to mask = ~mask.
+////////////////////////////////////////////////////////////////////
+template<class WType, int nbits>
+INLINE void BitMask<WType, nbits>::
+invert_in_place() {
+  _word = ~_word;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: BitMask::has_bits_in_common
+//       Access: Published
+//  Description: Returns true if this BitMask has any "one" bits in
+//               common with the other one, false otherwise.
+//
+//               This is equivalent to (mask & other) != 0, but may be
+//               faster.  (Actually, it should only be faster in the
+//               BitArray case, but this method is provided for the
+//               benefit of generic programming algorithms).
+////////////////////////////////////////////////////////////////////
+template<class WType, int nbits>
+INLINE bool BitMask<WType, nbits>::
+has_bits_in_common(const BitMask<WType, nbits> &other) const {
+  return (_word & other._word) != 0;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: BitMask::clear
+//       Access: Published
+//  Description: Sets all the bits in the BitMask off.
+////////////////////////////////////////////////////////////////////
+template<class WType, int nbits>
+INLINE void BitMask<WType, nbits>::
+clear() {
+  _word = 0;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: BitMask::output
 //       Access: Published
diff --git a/panda/src/putil/doubleBitMask.I b/panda/src/putil/doubleBitMask.I
index f465ebb531..ab48a5cb58 100644
--- a/panda/src/putil/doubleBitMask.I
+++ b/panda/src/putil/doubleBitMask.I
@@ -425,6 +425,136 @@ set_range_to(bool value, int low_bit, int size) {
   }
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: DoubleBitMask::get_num_on_bits
+//       Access: Published
+//  Description: Returns the number of bits that are set to 1 in the
+//               mask.
+////////////////////////////////////////////////////////////////////
+template<class BMType>
+INLINE int DoubleBitMask<BMType>::
+get_num_on_bits() const {
+  return _lo.get_num_on_bits() + _hi.get_num_on_bits();
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: DoubleBitMask::get_num_off_bits
+//       Access: Published
+//  Description: Returns the number of bits that are set to 0 in the
+//               mask.
+////////////////////////////////////////////////////////////////////
+template<class BMType>
+INLINE int DoubleBitMask<BMType>::
+get_num_off_bits() const {
+  return _lo.get_num_off_bits() + _hi.get_num_off_bits();
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: DoubleBitMask::get_lowest_on_bit
+//       Access: Published
+//  Description: Returns the index of the lowest 1 bit in the mask.
+//               Returns -1 if there are no 1 bits.
+////////////////////////////////////////////////////////////////////
+template<class BMType>
+INLINE int DoubleBitMask<BMType>::
+get_lowest_on_bit() const {
+  int result = _lo.get_lowest_on_bit();
+  if (result == -1) {
+    result = _hi.get_lowest_on_bit();
+    if (result != -1) {
+      result += half_bits;
+    }
+  }
+  return result;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: DoubleBitMask::get_lowest_off_bit
+//       Access: Published
+//  Description: Returns the index of the lowest 0 bit in the mask.
+//               Returns -1 if there are no 0 bits.
+////////////////////////////////////////////////////////////////////
+template<class BMType>
+INLINE int DoubleBitMask<BMType>::
+get_lowest_off_bit() const {
+  int result = _lo.get_lowest_off_bit();
+  if (result == -1) {
+    result = _hi.get_lowest_off_bit();
+    if (result != -1) {
+      result += half_bits;
+    }
+  }
+  return result;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: DoubleBitMask::get_highest_on_bit
+//       Access: Published
+//  Description: Returns the index of the highest 1 bit in the mask.
+//               Returns -1 if there are no 1 bits.
+////////////////////////////////////////////////////////////////////
+template<class BMType>
+INLINE int DoubleBitMask<BMType>::
+get_highest_on_bit() const {
+  int result = _hi.get_highest_on_bit();
+  if (result == -1) {
+    result = _lo.get_highest_on_bit();
+  } else {
+    result += half_bits;
+  }
+  return result;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: DoubleBitMask::get_highest_off_bit
+//       Access: Published
+//  Description: Returns the index of the highest 0 bit in the mask.
+//               Returns -1 if there are no 0 bits.
+////////////////////////////////////////////////////////////////////
+template<class BMType>
+INLINE int DoubleBitMask<BMType>::
+get_highest_off_bit() const {
+  int result = _hi.get_highest_off_bit();
+  if (result == -1) {
+    result = _lo.get_highest_off_bit();
+  } else {
+    result += half_bits;
+  }
+  return result;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: DoubleBitMask::get_next_higher_different_bit
+//       Access: Published
+//  Description: Returns the index of the next bit in the mask, above
+//               low_bit, whose value is different that the value of
+//               low_bit.  Returns low_bit again if all bits higher
+//               than low_bit have the same value.
+//
+//               This can be used to quickly iterate through all of
+//               the bits in the mask.
+////////////////////////////////////////////////////////////////////
+template<class BMType>
+INLINE int DoubleBitMask<BMType>::
+get_next_higher_different_bit(int low_bit) const {
+  if (low_bit > half_bits) {
+    return _hi.get_next_higher_different_bit(low_bit - half_bits) + half_bits;
+  }
+  int result = _lo.get_next_higher_different_bit(low_bit);
+  if (result != low_bit) {
+    return result;
+  }
+  if (_lo.get_bit(low_bit)) {
+    result = _hi.get_lowest_off_bit();
+  } else {
+    result = _hi.get_lowest_on_bit();
+  }
+  if (result == -1) {
+    return low_bit;
+  }
+  return result + half_bits;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: DoubleBitMask::invert_in_place
 //       Access: Published
diff --git a/panda/src/putil/doubleBitMask.h b/panda/src/putil/doubleBitMask.h
index 56e805d0c4..0bf97dc5ca 100644
--- a/panda/src/putil/doubleBitMask.h
+++ b/panda/src/putil/doubleBitMask.h
@@ -76,6 +76,14 @@ PUBLISHED:
   INLINE void clear_range(int low_bit, int size);
   INLINE void set_range_to(bool value, int low_bit, int size);
 
+  INLINE int get_num_on_bits() const;
+  INLINE int get_num_off_bits() const;
+  INLINE int get_lowest_on_bit() const;
+  INLINE int get_lowest_off_bit() const;
+  INLINE int get_highest_on_bit() const;
+  INLINE int get_highest_off_bit() const;
+  INLINE int get_next_higher_different_bit(int low_bit) const;
+
   INLINE void invert_in_place();
   INLINE bool has_bits_in_common(const DoubleBitMask<BMType> &other) const;
   INLINE void clear();