00001 /* 00002 Copyright (C) 2006, 2008 Sony Computer Entertainment Inc. 00003 All rights reserved. 00004 00005 This software is provided 'as-is', without any express or implied warranty. 00006 In no event will the authors be held liable for any damages arising from the use of this software. 00007 Permission is granted to anyone to use this software for any purpose, 00008 including commercial applications, and to alter it and redistribute it freely, 00009 subject to the following restrictions: 00010 00011 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 00012 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 00013 3. This notice may not be removed or altered from any source distribution. 00014 00015 */ 00016 00017 00018 #ifndef __BOXBOXDISTANCE_H__ 00019 #define __BOXBOXDISTANCE_H__ 00020 00021 00022 #include "Box.h" 00023 00024 00025 //--------------------------------------------------------------------------- 00026 // boxBoxDistance: 00027 // 00028 // description: 00029 // this computes info that can be used for the collision response of two boxes. when the boxes 00030 // do not overlap, the points are set to the closest points of the boxes, and a positive 00031 // distance between them is returned. if the boxes do overlap, a negative distance is returned 00032 // and the points are set to two points that would touch after the boxes are translated apart. 00033 // the contact normal gives the direction to repel or separate the boxes when they touch or 00034 // overlap (it's being approximated here as one of the 15 "separating axis" directions). 00035 // 00036 // returns: 00037 // positive or negative distance between two boxes. 00038 // 00039 // args: 00040 // vmVector3& normal: set to a unit contact normal pointing from box A to box B. 00041 // 00042 // BoxPoint& boxPointA, BoxPoint& boxPointB: 00043 // set to a closest point or point of penetration on each box. 00044 // 00045 // Box boxA, Box boxB: 00046 // boxes, represented as 3 half-widths 00047 // 00048 // const vmTransform3& transformA, const vmTransform3& transformB: 00049 // box transformations, in world coordinates 00050 // 00051 // float distanceThreshold: 00052 // the algorithm will exit early if it finds that the boxes are more distant than this 00053 // threshold, and not compute a contact normal or points. if this distance returned 00054 // exceeds the threshold, all the other output data may not have been computed. by 00055 // default, this is set to MAX_FLOAT so it will have no effect. 00056 // 00057 //--------------------------------------------------------------------------- 00058 00059 float 00060 boxBoxDistance(vmVector3& normal, BoxPoint& boxPointA, BoxPoint& boxPointB, 00061 PE_REF(Box) boxA, const vmTransform3 & transformA, PE_REF(Box) boxB, 00062 const vmTransform3 & transformB, 00063 float distanceThreshold = FLT_MAX ); 00064 00065 #endif /* __BOXBOXDISTANCE_H__ */