File content as of revision 0:494acf21d3bc:

#include "math.h"

/*
    Constants
*/

const float L_max = 50.0;   // Max arm length
const float L_min = 30.0;   // Min arm length

const float d = 30.0;       // Distance between arm centres of rotation 
const float h = 30.0;       // Height of lower arm centre of rotation                       TODO -- Determine

const float reach = 2*sqrt(pow(L_max,2)-pow(L_min,2))-d;    // Total length of wall that can be covered

const float y_max = (2*h + d)/2 + reach/2;
const float y_min = (2*h + d)/2 - reach/2;

const float x_min = L_min;
const float x_max = 0;                                                                          // TODO

/*
    Methods
*/

// Sets the required arm lengths in the 'upper' and 'lower' parameters
void getArmLengthsForRollerPosition(float x, float y, float &upper, float &lower) {
    lower = sqrt(pow(y-h,2)+pow(x,2));
    upper = sqrt(pow(lower,2)+pow(d,2)-2*d*sqrt(pow(lower,2)-pow(x,2)));
}

// Sets the roller position corresponding to the current arm lengths in the x and y parameters
void getRollerPositionForArmLengths(float upper, float lower, float &x, float &y) {
    y=(pow(lower,2)-pow(upper,2)+2*h*d+pow(d,2))/(2*d);
    x=sqrt(pow(upper,2)-pow(y-h,2)); //TODO
}

/*
    Getters
*/

float getMaximalArmLength(){
    return L_max;
}

float getMinimalArmLength(){
    return L_min;
}

float getReach(){
    return reach;
}

float getMaximalRollerHeight(){
    return y_max;
}

float getMinimalRollerHeight(){
    return y_min;
}