diff options
-rw-r--r-- | source/blender/blenlib/BLI_math_bits.h | 8 | ||||
-rw-r--r-- | source/blender/blenlib/intern/math_bits_inline.c | 25 |
2 files changed, 33 insertions, 0 deletions
diff --git a/source/blender/blenlib/BLI_math_bits.h b/source/blender/blenlib/BLI_math_bits.h index 248b615e3f8..86213dc271f 100644 --- a/source/blender/blenlib/BLI_math_bits.h +++ b/source/blender/blenlib/BLI_math_bits.h @@ -35,10 +35,18 @@ extern "C" { MINLINE int bitscan_forward_i(int a); MINLINE unsigned int bitscan_forward_uint(unsigned int a); +/* Similar to above, but also clears the bit. */ +MINLINE int bitscan_forward_clear_i(int *a); +MINLINE unsigned int bitscan_forward_clear_uint(unsigned int *a); + /* Search the value from MSB to LSB for a set bit. Returns index of this bit. */ MINLINE int bitscan_reverse_i(int a); MINLINE unsigned int bitscan_reverse_uint(unsigned int a); +/* Similar to above, but also clears the bit. */ +MINLINE int bitscan_reverse_clear_i(int *a); +MINLINE unsigned int bitscan_reverse_clear_uint(unsigned int *a); + /* NOTE: Those functions returns 2 to the power of index of highest order bit. */ MINLINE unsigned int highest_order_bit_uint(unsigned int n); MINLINE unsigned short highest_order_bit_s(unsigned short n); diff --git a/source/blender/blenlib/intern/math_bits_inline.c b/source/blender/blenlib/intern/math_bits_inline.c index e967ecbb3a3..d96cf969dae 100644 --- a/source/blender/blenlib/intern/math_bits_inline.c +++ b/source/blender/blenlib/intern/math_bits_inline.c @@ -44,6 +44,18 @@ MINLINE unsigned int bitscan_forward_uint(unsigned int a) return (unsigned int)bitscan_forward_i((int)a); } +MINLINE int bitscan_forward_clear_i(int *a) +{ + int i = bitscan_forward_i(*a); + *a &= (*a) - 1; + return i; +} + +MINLINE unsigned int bitscan_forward_clear_uint(unsigned int *a) +{ + return (unsigned int)bitscan_forward_clear_i((int *)a); +} + MINLINE int bitscan_reverse_i(int a) { BLI_assert(a != 0); @@ -61,6 +73,19 @@ MINLINE unsigned int bitscan_reverse_uint(unsigned int a) return (unsigned int)bitscan_reverse_i((int)a); } +MINLINE int bitscan_reverse_clear_i(int *a) +{ + int i = bitscan_reverse_i(*a); + /* TODO(sergey): This could probably be optimized. */ + *a &= ~(1 << (sizeof(int) * 8 - i - 1)); + return i; +} + +MINLINE unsigned int bitscan_reverse_clear_uint(unsigned int *a) +{ + return (unsigned int)bitscan_reverse_clear_i((int *)a); +} + MINLINE unsigned int highest_order_bit_uint(unsigned int n) { if (n == 0) { |