diff globalForces.mm @ 0:c667dfe12d47

OK. Ther real deal.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/globalForces.mm	Mon Nov 19 13:00:42 2012 +0000
@@ -0,0 +1,122 @@
+//
+//  globalForces.cpp
+//  wablet
+//
+//  Created by Robert Tubb on 18/07/2011.
+//  Copyright 2011 __MyCompanyName__. All rights reserved.
+//
+
+#include "globalForces.h"
+
+
+//-----------------------------------------------------------
+GlobalForces::GlobalForces(): grav(0.0,0.0){
+    //construct
+    gravityOn = true;
+    
+    speedLimit = 100.0;
+    wallBounce = 0.5;
+    
+    pressureAmt = 0.0;
+    gravityAmt = 0.2;
+    touchStrength = 1.0;
+    homingAmt = 0.0;
+    avFilterAmt = 0.0;
+    
+    pressure = 0.0;
+    volume = 1.0;
+    
+    maxForcePoints = 11;
+    excitationType = POSITION;
+    excitationShape = NOISE;
+    
+    forceTouchPoints = new forceTouchPoint[maxForcePoints];
+    for(int i = 0; i< 11; i++){
+        forceTouchPoints[i].x = 0.0;
+        forceTouchPoints[i].y = 0.0;
+        forceTouchPoints[i].tid = -1;
+        
+    }
+    
+    
+}
+
+//-----------------------------------------------------------
+GlobalForces::~GlobalForces(){
+    //destruct
+    
+}
+void GlobalForces::update(){
+    // gravity 
+    grav.setCoord(ofxAccelerometer.getForce().y * 0.015 * gravityAmt, ofxAccelerometer.getForce().x * 0.015 * gravityAmt);
+    // time step
+    delt = 1/ofGetFrameRate();
+    
+}
+//-----------------------------------------------------------
+// this is actually only called from dropletmesh.update
+void GlobalForces::setPressure(double aP){
+    
+    pressure = pressureAmt*aP;
+}
+//-----------------------------------------------------------
+void GlobalForces::createForceTouchPoint(double ax,double ay, int touchId){
+
+    forceTouchPoints[touchId].x = ax;
+    forceTouchPoints[touchId].y = ay;
+    forceTouchPoints[touchId].tid = touchId; 
+
+    
+    
+}
+//-----------------------------------------------------------
+void GlobalForces::moveForceTouchPoint(double ax,double ay, int touchId){
+    //
+    for(int i = 0;i<maxForcePoints; i++){
+        if(forceTouchPoints[touchId].tid == touchId){
+            forceTouchPoints[touchId].x = ax;
+            forceTouchPoints[touchId].y = ay;            
+        }
+    }
+    
+}
+//-----------------------------------------------------------
+void GlobalForces::removeForceTouchPoint(int touchId){
+    //
+    for(int i = 0;i<maxForcePoints; i++){
+        if(forceTouchPoints[i].tid == touchId){
+            forceTouchPoints[i].tid = -1;          
+        }
+    } 
+}
+//-----------------------------------------------------------
+TwoVector GlobalForces::getAllForceAt(double ax, double ay){
+    //this is called for every mass point so work out most stuff in update()
+    TwoVector force(0.0,0.0);
+    double fmag, r;
+    if(gravityOn){
+        
+        force.x += grav.x;
+        force.y += grav.y;
+    }
+    
+    // now touch points
+     for(int i = 0;i<maxForcePoints; i++){
+         // work out distance to force point and then use 1/r^2 rule 
+         if(forceTouchPoints[i].tid != -1){
+             TwoVector diff(forceTouchPoints[i].x - ax, forceTouchPoints[i].y - ay );
+             r = diff.norm();
+             if (r < 0.03){ // try avoid very small distances giving ridiculous forces
+                 fmag = 0.0;
+             }else{
+                 fmag = touchStrength*1/(1000*(r*r));
+             } 
+            force.x -= fmag*diff.x/r;
+            force.y -= fmag*diff.y/r;
+             
+         }
+     }
+    
+    return force;
+}
+//-----------------------------------------------------------
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