diff options
author | Campbell Barton <ideasman42@gmail.com> | 2014-04-03 14:47:03 +0400 |
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committer | Campbell Barton <ideasman42@gmail.com> | 2014-04-03 14:47:03 +0400 |
commit | 5770d691bbed31d05ecf22383f56df2a4371acfa (patch) | |
tree | 54b0ee57d35e4ca3b66b4bc4a44bdf51c807aee3 /source/blender/blenlib/intern/convexhull2d.c | |
parent | 51abc2becd602676eeebc24ba7dc64c804bb935a (diff) |
Optimize BLI_convexhull_aabb_fit_hull_2d, avoid atan2, sin, cos
add utility functions for using a 2d unit vector as a rotation matrix
mul_v2_v2_cw & mul_v2_v2_ccw
Diffstat (limited to 'source/blender/blenlib/intern/convexhull2d.c')
-rw-r--r-- | source/blender/blenlib/intern/convexhull2d.c | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/source/blender/blenlib/intern/convexhull2d.c b/source/blender/blenlib/intern/convexhull2d.c index 2c29ef042a1..9f509638e3b 100644 --- a/source/blender/blenlib/intern/convexhull2d.c +++ b/source/blender/blenlib/intern/convexhull2d.c @@ -253,28 +253,24 @@ float BLI_convexhull_aabb_fit_hull_2d(const float (*points_hull)[2], unsigned in { unsigned int i, i_prev; float area_best = FLT_MAX; - float angle_best = 0.0f; + float dvec_best[2]; /* best angle, delay atan2 */ i_prev = n - 1; for (i = 0; i < n; i++) { const float *ev_a = points_hull[i]; const float *ev_b = points_hull[i_prev]; - float dvec[2]; + float dvec[2]; /* 2d rotation matrix */ sub_v2_v2v2(dvec, ev_a, ev_b); if (normalize_v2(dvec) != 0.0f) { - float mat[2][2]; + /* rotation matrix */ float min[2] = {FLT_MAX, FLT_MAX}, max[2] = {-FLT_MAX, -FLT_MAX}; - unsigned int j; - const float angle = atan2f(dvec[0], dvec[1]); float area; - angle_to_mat2(mat, angle); - for (j = 0; j < n; j++) { float tvec[2]; - mul_v2_m2v2(tvec, mat, points_hull[j]); + mul_v2_v2_cw(tvec, dvec, points_hull[j]); min[0] = min_ff(min[0], tvec[0]); min[1] = min_ff(min[1], tvec[1]); @@ -290,14 +286,14 @@ float BLI_convexhull_aabb_fit_hull_2d(const float (*points_hull)[2], unsigned in if (area < area_best) { area_best = area; - angle_best = angle; + copy_v2_v2(dvec_best, dvec); } } i_prev = i; } - return angle_best; + return (area_best != FLT_MAX) ? atan2f(dvec_best[0], dvec_best[1]) : 0.0f; } /** |