Processing program for histogram matching (work in progress)

histogramMatching.pde

float ideal[] = {
  0.092, 
  0.518, 
  0.846, 
  1.000, 
  0.960, 
  0.850, 
  0.740, 
  0.640, 
  0.550, 
  0.456, 
  0.378, 
  0.300, 
  0.222, 
  0.144, 
  0.086, 
  0.034, 
  0.008
};

void setup() {
  size(1000, 500);
 
}

void draw() {
  background(255);
  println(ideal.length); 
  noFill(); 
  
  float cumulative = 0; 
  for (int i=0; i<1000; i++){
    float t = map(i, 0,1000, 0,ideal.length-1); 
    t = constrain(t, 0,ideal.length-1); 
    float index1 = floor(t); 
    float index2 = ceil(t); 
    float index0 = max(0,  index1 - 1);
    float index3 = min(ideal.length-1, index2 + 1);
    
    float frac = t - index1; 
    float val0 = ideal[(int)index0]; 
    float val1 = ideal[(int)index1]; 
    float val2 = ideal[(int)index2]; 
    float val3 = ideal[(int)index3]; 
    
    float valt = curvePoint(val0, val1, val2, val3, frac);
    float x = i; 
    float y = valt * 200 * 0.990; 
    stroke(0);
    line (x, 200, x, 200-y); 
    
    float b = 557.0; 
    float c = 65.0;
    float d = 60.0;
    float valg = exp(0 - (sq(100*log(x+d)-b))/(2.0*c*c));
    float gy = 199 * valg; 
    stroke(0,180,0, 180); 
    ellipse(x,200-gy, 2,2); 
    
    
    cumulative += valg; //valt; 
    float cumy = cumulative; 
    stroke(255,0,0, 127); 
    line (x, 500, x, 500 - cumy); 
    
    
    
  }
  
  
  
  
}