Diff: classPointMass.h

Revision:

0:df6fdd9b99f0

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/classPointMass.h	Tue Dec 02 04:39:15 2014 +0000
@@ -0,0 +1,103 @@
+/*
+ *  pointMass.h
+ *  laserBlob
+ *
+ *  Created by CASSINELLI ALVARO on 5/19/11.
+ *  Copyright 2011 TOKYO UNIVERSITY. All rights reserved.
+ *
+ */
+
+#ifndef POINTMASS_H
+#define POINTMASS_H
+
+#include "myVectorClass.h"
+
+#define VERLET_METHOD // comment this to have EULER method
+
+#define MAX_PERMISSIBLE_SPEED 35
+
+class pointMass
+{
+public:
+    
+    // ==================================== Static variables and methods ============== 
+    static vector2Df maxWall, minWall; //equal for ALL THE MASS OBJECTS (declare static). But it could be per-mass. The problem with that approach would be too much wasted memory. 
+    // NOTE: - a static member variable has the same value in any instance of the class and doesn't even require an instance of the class to exist.
+    //       - a static class member cannot be initialized inside of the class declaration. In fact, if you decide to put your code in a header file, you cannot even initialize the static variable 
+    //         inside of the header file; do it in a .cpp file instead. Moreover, you are required to initialize the static class member or it will not be in scope. 
+    //         The syntax is a bit weird: "type class_name::static_variable = value", or in this case vector2Df pointMass::maxWall(4095, 4095)
+   
+    // methods:
+    static void setWallLimits(float mminx, float mminy, float mmaxx, float mmaxy);
+    
+    // ==================================== METHODS ====================================
+    pointMass();
+    virtual ~pointMass(){};
+        
+    // Adding forces to total force:
+    void resetForce();
+    void addForce(float x, float y);
+    void addForce(vector2Df force);
+    void addDampingForce();
+    void addInvSquareForce(float x, float y, float radiusMax, float radiusMin, float scale);
+    void addInterInvSquareForce(pointMass &p, float radiusMin, float radiusMax, float scale);
+        
+    // (a blob object could be defined by a "cord" of chained particles, plus a center)
+    void addSpringForce(float x, float y,  float radius, float scale);
+    void addInterSpringForce(pointMass &p, float radius, float scale);
+    //void addClockwiseForce(particle &p, float radius, float scale);
+    //void addCounterClockwiseForce(particle &p, float radius, float scale);
+    
+    //void addDampingForce(); // this work in the case of the euler integration; in case of Verlet, we need to do pseudo-damping while calculating
+    // the acceleration... 
+    
+    // Set parameters:
+    void setInitialCondition(float px, float py, float vx, float vy);
+    void setInitialCondition(vector2Df _pos, vector2Df _speed);
+    void setIntegrationStep(float _dt);
+    
+    void setPos(float px, float py); // assuming the speed is unchanged (must do some tweaking in case of Verlet integration)
+    
+    // dynamic update:
+    void update();
+    
+    // kinematic constraints (could be based on a force too...)
+    //void setWallLimits(float mminx, float mminy, float mmaxx, float mmaxy); // DECLARED STATIC
+    void bounceOffWalls();
+    
+    vector2Df getSpeed(); // get an estimation of the speed (also update speed variable - this variable is not needed in case of VERLET)
+    void setSpeed(const vector2Df& vel);
+    void setSpeed(float vx, float vy);
+    
+    // ==================================== VARIABLES ====================================
+    
+    int identifier; // this may be needed in particular in case we don't use vector<> (case of poor C Arduino compiler)
+    
+    // kinematic variables:
+    vector2Df  pos, posOld; // I will use verlet integration (perhaps we could have a switch to choose the integration method?)
+    //vector2D  speed; // speed at time t (this is not explicitly calculated in case of verlet method, HENCE PRIVATE)
+    vector2Df  acc;   // Acceleration at time t (equal to the total force divided by the mass). No real need to have it here, but convenient to check. 
+    vector2Df  totalForce; // this is just for convenience and speeding up calculation when adding forces, before computing acc. 
+    
+    // integration step:
+    float dt; 
+    
+    // physical parameters:
+    float dampMotion;
+    float dampBorder;
+    float mass;
+    bool  bFixed; // these could act as control points that could be loaded (letters...). In fact, we could use mass to set this (like mass=-1)
+    
+    // other things:   
+    bool bWallCollision; // this is generic (detect any collision with a side)
+    vector2Df innerCollitionDirection; // this is smarter than a boolean, because I can detect which side was touched and do different things (but may be memory consuming)
+    
+protected:
+    
+private:
+      vector2Df  speed; // speed at time t (this is not explicitly calculated in case of verlet method, HENCE MAY BE PRIVATE)
+    
+};
+
+
+#endif //POINTMASS_H
\ No newline at end of file