preliminary physics, sound, hud

[chaz/yoink] / src / Moof / State.hh

diff --git a/src/Moof/State.hh b/src/Moof/State.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_STATE_HH_
+#define _MOOF_STATE_HH_
+
+#include <Moof/Math.hh>
+
+
+namespace Mf {
+
+
+template <typename T>
+struct Derivative
+{
+       inline virtual ~Derivative() {}
+
+       virtual T operator*(Scalar dt) const = 0;
+       virtual T operator+(const T& other) const = 0;
+};
+
+
+/**
+ * Structure containing any information needed to place and orient an animate
+ * object in 3-space as well as predict future locations and orientations.
+ */
+
+template <typename T, typename D>
+struct State
+{
+       inline virtual ~State() {}
+
+       inline D evaluate(Scalar t)
+       {
+               D derivative;
+               calculateDerivatives(derivative, t);
+               return derivative;
+       }
+
+       inline D evaluate(Scalar t, Scalar dt, const D& derivative)
+       {
+               T state = *this;
+               state += derivative * dt;
+               state.recalculate();
+
+               D newDerivative;
+               calculateDerivatives(newDerivative, t);
+               return newDerivative;
+       }
+
+       inline void integrate(Scalar t, Scalar dt)
+       {
+               D a = evaluate(t);
+               D b = evaluate(t, dt * 0.5, a);
+               D c = evaluate(t, dt * 0.5, b);
+               D d = evaluate(t, dt, c);
+
+               *this += (a + (b + c) * 2.0 + d) * (1.0/6.0) * dt;
+       }
+
+       virtual void recalculate() {}
+
+       virtual void calculateDerivatives(D& derivative, Scalar t) = 0;
+       virtual T interpolate(Scalar alpha, const T& prevState) const = 0;
+
+       virtual T& operator+=(const D& derivative) = 0;
+};
+
+
+} // namespace Mf
+
+#endif // _MOOF_STATE_HH_
+
+/** vim: set ts=4 sw=4 tw=80: *************************************************/
+