X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;f=src%2FMoof%2FPhysics.hh;fp=src%2FMoof%2FPhysics.hh;h=a79a5c3604b8b88c66b2a63039c5bc8d8d57db9c;hb=bfa6212d09d8735d8fd5e2638188e4a99f21ada4;hp=0000000000000000000000000000000000000000;hpb=eebb993ca929c3f4c235cad9e01dc4797fcd2945;p=chaz%2Fyoink

diff --git a/src/Moof/Physics.hh b/src/Moof/Physics.hh
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+
+/*******************************************************************************
+
+ Copyright (c) 2009, Charles McGarvey
+ All rights reserved.
+ 
+ Redistribution   and   use  in  source  and  binary  forms,  with  or  without
+ modification, are permitted provided that the following conditions are met:
+ 
+   * Redistributions  of  source  code  must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+   * Redistributions  in binary form must reproduce the above copyright notice,
+     this  list of conditions and the following disclaimer in the documentation
+     and/or other materials provided with the distribution.
+ 
+ THIS  SOFTWARE  IS  PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND  ANY  EXPRESS  OR  IMPLIED  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED.  IN  NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR  ANY  DIRECT,  INDIRECT,  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES  (INCLUDING,  BUT  NOT  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES;  LOSS  OF  USE,  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*******************************************************************************/
+
+#ifndef _MOOF_PHYSICS_HH_
+#define _MOOF_PHYSICS_HH_
+
+#include <Moof/Math.hh>
+
+
+namespace Mf {
+
+// Generic implementation of the RK4 integrator.  To use, you need one type
+// representing the state and another containing the derivatives of the state.
+
+template<typename S, typename D>
+inline D evaluate(const S& state, Scalar t)
+{
+	D derivative;
+	state.getDerivative(derivative, t);
+	return derivative;
+}
+
+template<typename S, typename D>
+inline D evaluate(const S& state,  Scalar t, Scalar dt, const D& derivative)
+{
+	S temp = state;
+	temp.applyDerivative(derivative, dt);
+	return evaluate<S,D>(temp, t + dt);
+}
+
+
+template<typename S, typename D>
+inline void integrate(S& state, Scalar t, Scalar dt)
+{
+	D a = evaluate<S,D>(state, t);
+	D b = evaluate<S,D>(state, t, dt * 0.5, a);
+	D c = evaluate<S,D>(state, t, dt * 0.5, b);
+	D d = evaluate<S,D>(state, t, dt, c);
+
+	//state += (a + (b + c) * 2.0 + d) * (1.0/6.0) * dt;
+	state.applyDerivative((a + (b + c) * 2.0 + d) * (1.0/6.0), dt);
+}
+
+
+} // namespace Mf
+
+#endif // _MOOF_PHYSICS_HH_
+
+/** vim: set ts=4 sw=4 tw=80: *************************************************/
+