diff options
Diffstat (limited to 'source/blender/python/generic/Mathutils.c')
| -rw-r--r-- | source/blender/python/generic/Mathutils.c | 35 |
1 files changed, 17 insertions, 18 deletions
diff --git a/source/blender/python/generic/Mathutils.c b/source/blender/python/generic/Mathutils.c index 8ad388ac540..fc21c26dd74 100644 --- a/source/blender/python/generic/Mathutils.c +++ b/source/blender/python/generic/Mathutils.c @@ -557,25 +557,24 @@ static PyObject *M_Mathutils_ShearMatrix(PyObject * self, PyObject * args) /* Utility functions */ -/*---------------------- EXPP_FloatsAreEqual ------------------------- - Floating point comparisons - floatStep = number of representable floats allowable in between - float A and float B to be considered equal. */ -int EXPP_FloatsAreEqual(float A, float B, int floatSteps) -{ - int a, b, delta; - assert(floatSteps > 0 && floatSteps < (4 * 1024 * 1024)); - a = *(int*)&A; - if (a < 0) - a = 0x80000000 - a; - b = *(int*)&B; - if (b < 0) - b = 0x80000000 - b; - delta = abs(a - b); - if (delta <= floatSteps) - return 1; - return 0; +// LomontRRDCompare4, Ever Faster Float Comparisons by Randy Dillon +#define SIGNMASK(i) (-(int)(((unsigned int)(i))>>31)) + +int EXPP_FloatsAreEqual(float af, float bf, int maxDiff) +{ // solid, fast routine across all platforms + // with constant time behavior + int ai = *(int *)(&af); + int bi = *(int *)(&bf); + int test = SIGNMASK(ai^bi); + int diff, v1, v2; + + assert((0 == test) || (0xFFFFFFFF == test)); + diff = (ai ^ (test & 0x7fffffff)) - bi; + v1 = maxDiff + diff; + v2 = maxDiff - diff; + return (v1|v2) >= 0; } + /*---------------------- EXPP_VectorsAreEqual ------------------------- Builds on EXPP_FloatsAreEqual to test vectors */ int EXPP_VectorsAreEqual(float *vecA, float *vecB, int size, int floatSteps) |