diff options
author | mano-wii <germano.costa@ig.com.br> | 2018-10-01 06:16:44 +0300 |
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committer | mano-wii <germano.costa@ig.com.br> | 2018-10-01 06:16:44 +0300 |
commit | 9df476ecaac8fb82c3d28b7404374db09e73eda4 (patch) | |
tree | 6fc0dc198fa5da4ac7a9928562f6828e3e08e5a7 /source/blender/blenlib/intern/math_geom.c | |
parent | 1f2c4f8809aab37d04ee0c571c33466643e103b6 (diff) |
BLI_math: add `isect_seg_seg_v3` function and use in the cloth collision algorith.
In my tests a 4% improvement in performance was achieved by simulating a square cloth over the cube.
Diffstat (limited to 'source/blender/blenlib/intern/math_geom.c')
-rw-r--r-- | source/blender/blenlib/intern/math_geom.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c index fb2a1e47895..a5c84ed7645 100644 --- a/source/blender/blenlib/intern/math_geom.c +++ b/source/blender/blenlib/intern/math_geom.c @@ -1123,6 +1123,70 @@ int isect_seg_seg_v2(const float v1[2], const float v2[2], const float v3[2], co return ISECT_LINE_LINE_NONE; } +/* Returns a point on each segment that is closest to the other. */ +void isect_seg_seg_v3( + const float a0[3], const float a1[3], + const float b0[3], const float b1[3], + float r_a[3], float r_b[3]) +{ + float fac_a, fac_b; + float a_dir[3], b_dir[3], a0b0[3], crs_ab[3]; + sub_v3_v3v3(a_dir, a1, a0); + sub_v3_v3v3(b_dir, b1, b0); + sub_v3_v3v3(a0b0, b0, a0); + cross_v3_v3v3(crs_ab, b_dir, a_dir); + const float nlen = len_squared_v3(crs_ab); + + if (nlen == 0.0f) { + /* Parallel Lines */ + /* In this case return any point that + * is between the closest segments. */ + float a0b1[3], a1b0[3], len_a, len_b, fac1, fac2; + sub_v3_v3v3(a0b1, b1, a0); + sub_v3_v3v3(a1b0, b0, a1); + len_a = len_squared_v3(a_dir); + len_b = len_squared_v3(b_dir); + + if (len_a) { + fac1 = dot_v3v3(a0b0, a_dir); + fac2 = dot_v3v3(a0b1, a_dir); + CLAMP(fac1, 0.0f, len_a); + CLAMP(fac2, 0.0f, len_a); + fac_a = (fac1 + fac2) / (2 * len_a); + } + else { + fac_a = 0.0f; + } + + if (len_b) { + fac1 = -dot_v3v3(a0b0, b_dir); + fac2 = -dot_v3v3(a1b0, b_dir); + CLAMP(fac1, 0.0f, len_b); + CLAMP(fac2, 0.0f, len_b); + fac_b = (fac1 + fac2) / (2 * len_b); + } + else { + fac_b = 0.0f; + } + } + else { + float c[3], cray[3]; + sub_v3_v3v3(c, crs_ab, a0b0); + + cross_v3_v3v3(cray, c, b_dir); + fac_a = dot_v3v3(cray, crs_ab) / nlen; + + cross_v3_v3v3(cray, c, a_dir); + fac_b = dot_v3v3(cray, crs_ab) / nlen; + + CLAMP(fac_a, 0.0f, 1.0f); + CLAMP(fac_b, 0.0f, 1.0f); + } + + madd_v3_v3v3fl(r_a, a0, a_dir, fac_a); + madd_v3_v3v3fl(r_b, b0, b_dir, fac_b); +} + /** * Get intersection point of two 2D segments. * |