From db8293d4561791b4ddb349fa3ce37803afe509ee Mon Sep 17 00:00:00 2001 From: Campbell Barton Date: Thu, 26 Dec 2013 12:21:40 +1100 Subject: Polyfill: minor changes to which fix rare errors with float precision --- source/blender/blenlib/intern/polyfill2d.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/source/blender/blenlib/intern/polyfill2d.c b/source/blender/blenlib/intern/polyfill2d.c index 56cd385e76b..f5a226cebb6 100644 --- a/source/blender/blenlib/intern/polyfill2d.c +++ b/source/blender/blenlib/intern/polyfill2d.c @@ -50,8 +50,6 @@ #include "BLI_strict_flags.h" -#define SIGN_EPS 0.000001f - /* avoid fan-fill topology */ #define USE_CLIP_EVEN #define USE_CONVEX_SKIP @@ -97,7 +95,7 @@ static void pf_ear_tip_cut(PolyFill *pf, unsigned int index_ear_tip); BLI_INLINE eSign signum_i(float a) { - if (UNLIKELY(fabsf(a) < SIGN_EPS)) + if (UNLIKELY(a == 0.0f)) return 0; else if (a > 0.0f) return 1; @@ -105,9 +103,23 @@ BLI_INLINE eSign signum_i(float a) return -1; } +/** + * alternative version of #area_tri_signed_v2 + * needed because of float precision issues + * + * \note removes / 2 since its not needed since we only need ths sign. + */ +BLI_INLINE float area_tri_signed_v2_alt_2x(const float v1[2], const float v2[2], const float v3[2]) +{ + return ((v1[0] * (v2[1] - v3[1])) + + (v2[0] * (v3[1] - v1[1])) + + (v3[0] * (v1[1] - v2[1]))); +} + + static eSign span_tri_v2_sign(const float v1[2], const float v2[2], const float v3[2]) { - return signum_i(area_tri_signed_v2(v3, v2, v1)); + return signum_i(area_tri_signed_v2_alt_2x(v3, v2, v1)); } static unsigned int *pf_tri_add(PolyFill *pf) -- cgit v1.2.3