ContactForce2.java

package jass.contact;
import jass.engine.*;
import jass.generators.*;

/**
   A force model with impact, slide, and slide modes based on looping wav files
   Roll force is fed through modal filter.
   
   @author Kees van den Doel (kvdoel@cs.ubc.ca)
*/
public class ContactForce2 extends Out {

    // Has these protected sources:
    protected BangForce bangForce;
    protected LoopBuffer slideForce;
    protected LoopBuffer rollForceRaw;
    // modal filter for rolling
    protected ModalObjectWithOneContact rollForce;
    protected float dryRollGain = 0; // 1 for raw wav force, 0 for pure filtered

    // properties defining how physical parameters are mapped to audio parameters
    // [x0,x1] is range of x

    // maximum audio speeds, 1 is original wav file
    protected float slideSpeed1=1f,rollSpeed1=1f;

    // physical speed ranges
    protected float vslide0=.1f,vslide1=1f,vroll0=.1f,vroll1=1f;

    // gain ratios
    protected float physicalToAudioGainSlide=1,physicalToAudioGainRoll=1,physicalToAudioGainImpact=1;

    /** Set model parameters mapping physical units to audio units
        @param slideSpeed1 maximum audio loop speed (1 = original recording)
        @param rollSpeed1 maximum audio loop speed (1 = original recording)
        @param vslide0 minimum physical speed (lower than this is considered to be zero)
        @param vslide1 maximum physical speed (higher than this is set to this value)
        @param vroll0 minimum physical speed (lower than this is considered to be zero)
        @param vroll1 maximum physical speed (higher than this is set to this value)
        @param physicalToAudioGainSlide multiplies normal force to get slide gain
        @param physicalToAudioGainRoll multiplies normal force to get roll gain
        @param physicalToAudioGainImpact multiplies impact force to get impact gain
     */
    public void setStaticContactModelParameters(float slideSpeed1, float rollSpeed1, float vslide0,
                                                float vslide1, float vroll0, float vroll1,
                                                float physicalToAudioGainSlide,
                                                float physicalToAudioGainRoll,float physicalToAudioGainImpact) {
        this.slideSpeed1 = slideSpeed1;
        this.rollSpeed1 = rollSpeed1;
        this.vslide0 = vslide0;
        this.vslide1 = vslide1;
        this.vroll0  = vroll0;
        this.vroll1  = vroll1;
        this.physicalToAudioGainSlide = physicalToAudioGainSlide;
        this.physicalToAudioGainRoll = physicalToAudioGainRoll;
        this.physicalToAudioGainImpact = physicalToAudioGainImpact;
    }
    
    /** Contructor intended only for subclass constructors (super(bufferSize);)
     */
    protected ContactForce2(int bufferSize) {
        super(bufferSize);
    }
    
    /** Construct contact force from named files.
        @param srate sampling rate in Hertz.
        @param bufferSize bufferSize of this Out.
        @param fnImpact audio file name for impact. (For example cos20ms.wav.)
        @param fnSlide audio file name for slide. (For example grid.wav.)
        @param fnRoll audio file name for slide. (For example roll.wav.)
        @param m modal model to build roll filter from.
    */
    public ContactForce2(float srate, int bufferSize, String fnImpact,String fnSlide,String fnRoll, ModalModel m) {
        super(bufferSize);
        bangForce = new BangForce(srate,bufferSize,fnImpact);
        slideForce = new LoopBuffer(srate,bufferSize,fnSlide);
        rollForceRaw = new LoopBuffer(srate,bufferSize,fnRoll);
        bangForce.setTime(getTime());
        slideForce.setTime(getTime());
        rollForceRaw.setTime(getTime());
        rollForce = new ModalObjectWithOneContact(m,srate,bufferSize);
        try {
            rollForce.addSource(rollForceRaw);
        } catch(SinkIsFullException e) {
            System.out.println(this+" "+e);
        }
        bangForce.setTime(getTime());
        slideForce.setTime(getTime());
        rollForceRaw.setTime(getTime());
        rollForce.setTime(getTime());
    }

    /** Generate impact force  in physical units.
        @param force magnitude.
        @param dur duration in seconds of impact.
    */
    public synchronized void bang(float force, float dur) {
        bangForce.bang(physicalToAudioGainImpact*force,dur);
    }

    /** Set slide speed and normal force  in physical units.
        @param force normal force.
        @param speed relative surface velocity.
     */
    public synchronized void setSlideProperties(float force,float speed) {
        if(speed > vslide1) {
            speed = vslide1;
        } else if(speed < vslide0) {
            speed = 0;
            force = 0;
        }
        slideForce.setSpeed(speed * slideSpeed1/vslide1);
        float vol = (float)(Math.sqrt(force * speed/vslide1));
        slideForce.setVolume(physicalToAudioGainSlide*vol);
    }
    
    /** Set roll speed and normal force in physical units.
        @param force normal force.
        @param speed roll velocity. 
    */
    public synchronized void setRollProperties(float force,float speed) {
        if(speed > vroll1) {
            speed = vroll1;
        } else if(speed < vroll0) {
            speed = 0;
            force = 0;
        }
        rollForceRaw.setSpeed(speed * rollSpeed1/vroll1);
        float vol = (float)(Math.sqrt(force * speed/vroll1));
        rollForceRaw.setVolume(physicalToAudioGainRoll*vol);
    }

      
    /** Set roll force filter properties
    */
    public synchronized void setRollFilter(float damping, float dryRollGain) {
        rollForce.setDamping(damping);
        this.dryRollGain = dryRollGain;
    }

    /** Set roll force filter number of modes
        @param nf number of modes
    */
    public synchronized void setNf(int nf) {
        rollForce.setNf(nf);
    }

    /** Compute the next buffer.
     */
    public synchronized void computeBuffer() {
        try {
            float[] b1 = bangForce.getBuffer(getTime());
            float[] b2 = slideForce.getBuffer(getTime());
            float[] b3 = rollForceRaw.getBuffer(getTime());
            float[] b4 = rollForce.getBuffer(getTime());
            int bufsz = getBufferSize();
            for(int k=0;k<bufsz;k++) {
                buf[k] = b1[k] + b2[k] + dryRollGain*b3[k] + (1 - dryRollGain)*b4[k];
            }
        } catch(BufferNotAvailableException e) {
            System.out.println(this+" "+e);
        }
    }
}