Mercurial > hg > beaglert
diff projects/airharp/MassSpringDamper.cpp @ 164:40badaff5729 heavy-updated
- added more pd/heavy examples
- removed heavy-specific flags from Makefile
- added air-harp cpp example project
author | chnrx <chris.heinrichs@gmail.com> |
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date | Thu, 03 Dec 2015 16:19:33 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/projects/airharp/MassSpringDamper.cpp Thu Dec 03 16:19:33 2015 +0000 @@ -0,0 +1,59 @@ +/* + * + * Simple 1-Dimensional Mass Spring Damper + * + * Christian Heinrichs 04/2015 + * + */ + +#include "MassSpringDamper.h" + +MassSpringDamper::MassSpringDamper(float mass, float spring, float damp) { + + _dt = 1.0/44100.0; + _mass = mass; + _spring = spring; + _damp = damp; + _position = 0; + _velocity = 0; + +} + +void MassSpringDamper::setup() { + +} + +double MassSpringDamper::update(float inForce) { + + // 1. calculate spring/damper forces using current position and velocity + + double out = (_position * (double)_spring * -1) + (_velocity * (double)_damp * -1); + + // 2. apply external force + + out += inForce; + + // 3. derive acceleration (a = f/m) + + out /= (double)_mass; + + // 4. derive velocity (v = a*dt) + + out *= _dt; + + // 5. apply previous velocity + + out += _velocity; + + // 6. save current velocity state for next iteration + + _velocity = out; + + // 7. derive new position (x[n] = x[n-1] + v[n]) and save for next iteration + + out += _position; + _position = out; + + return out; + +}