1 /* 2 * Copyright (c) 2006-2009 Erin Catto http://www.box2d.org 3 * 4 * This software is provided 'as-is', without any express or implied 5 * warranty. In no event will the authors be held liable for any damages 6 * arising from the use of this software. 7 * Permission is granted to anyone to use this software for any purpose, 8 * including commercial applications, and to alter it and redistribute it 9 * freely, subject to the following restrictions: 10 * 1. The origin of this software must not be misrepresented; you must not 11 * claim that you wrote the original software. If you use this software 12 * in a product, an acknowledgment in the product documentation would be 13 * appreciated but is not required. 14 * 2. Altered source versions must be plainly marked as such, and must not be 15 * misrepresented as being the original software. 16 * 3. This notice may not be removed or altered from any source distribution. 17 */ 18 19 #ifndef B2_TIME_OF_IMPACT_H 20 #define B2_TIME_OF_IMPACT_H 21 22 #include <Box2D/Common/b2Math.h> 23 #include <Box2D/Collision/b2Distance.h> 24 25 /// Input parameters for b2TimeOfImpact 26 struct b2TOIInput 27 { 28 b2DistanceProxy proxyA; 29 b2DistanceProxy proxyB; 30 b2Sweep sweepA; 31 b2Sweep sweepB; 32 float32 tMax; // defines sweep interval [0, tMax] 33 }; 34 35 // Output parameters for b2TimeOfImpact. 36 struct b2TOIOutput 37 { 38 enum State 39 { 40 e_unknown, 41 e_failed, 42 e_overlapped, 43 e_touching, 44 e_separated 45 }; 46 47 State state; 48 float32 t; 49 }; 50 51 /// Compute the upper bound on time before two shapes penetrate. Time is represented as 52 /// a fraction between [0,tMax]. This uses a swept separating axis and may miss some intermediate, 53 /// non-tunneling collision. If you change the time interval, you should call this function 54 /// again. 55 /// Note: use b2Distance to compute the contact point and normal at the time of impact. 56 void b2TimeOfImpact(b2TOIOutput* output, const b2TOIInput* input); 57 58 #endif 59