From e7febd72d66ffe36c50d79684805142d8153f666 Mon Sep 17 00:00:00 2001 From: RaphaelHunter Date: Thu, 29 Aug 2019 14:17:08 +0800 Subject: a faster funtion to transform aabb --- core/math/transform.h | 39 +++++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 16 deletions(-) (limited to 'core/math') diff --git a/core/math/transform.h b/core/math/transform.h index 4c8d915305..2448aecdc6 100644 --- a/core/math/transform.h +++ b/core/math/transform.h @@ -154,22 +154,29 @@ _FORCE_INLINE_ Plane Transform::xform_inv(const Plane &p_plane) const { } _FORCE_INLINE_ AABB Transform::xform(const AABB &p_aabb) const { - /* define vertices */ - Vector3 x = basis.get_axis(0) * p_aabb.size.x; - Vector3 y = basis.get_axis(1) * p_aabb.size.y; - Vector3 z = basis.get_axis(2) * p_aabb.size.z; - Vector3 pos = xform(p_aabb.position); - //could be even further optimized - AABB new_aabb; - new_aabb.position = pos; - new_aabb.expand_to(pos + x); - new_aabb.expand_to(pos + y); - new_aabb.expand_to(pos + z); - new_aabb.expand_to(pos + x + y); - new_aabb.expand_to(pos + x + z); - new_aabb.expand_to(pos + y + z); - new_aabb.expand_to(pos + x + y + z); - return new_aabb; + + /* http://dev.theomader.com/transform-bounding-boxes/ */ + Vector3 min = p_aabb.position; + Vector3 max = p_aabb.position + p_aabb.size; + Vector3 tmin, tmax; + for (int i = 0; i < 3; i++) { + tmin[i] = tmax[i] = origin[i]; + for (int j = 0; j < 3; j++) { + real_t e = basis[i][j] * min[j]; + real_t f = basis[i][j] * max[j]; + if (e < f) { + tmin[i] += e; + tmax[i] += f; + } else { + tmin[i] += f; + tmax[i] += e; + } + } + } + AABB r_aabb; + r_aabb.position = tmin; + r_aabb.size = tmax - tmin; + return r_aabb; } _FORCE_INLINE_ AABB Transform::xform_inv(const AABB &p_aabb) const { -- cgit v1.2.3