I am making a slider that changes the tint of an image. I looked some of the code from here  http://processing.org/learning/topics/scrollbar.html. However i want the slider to change according to a given min and max value in the constructor. In this case 0 to 255, and the slider needs to be relative to the screen size. This is how i did it, the screen size of 600 is the same as the max value of 255. Now 255 is the same as 100% of the width. Now i calculated this with a decrease ratio to get the same value of 255. However the calculation acts in a sort of Fibonacci style :). My question is can this be done with min() and max(). The slider need to be relative to the screen and the min, max  values need to be 100%.

Thanks

2. PImage img;
3. Scroller scroll;
4. Scroller scroll1;
5. 
   
6. void setup(){
7.   size(600, 600);
8.   img = loadImage("lake.jpg");
9.   
10.   scroll = new Scroller(0, 0, 32, 32);
11.   scroll1 = new Scroller(0, 40, 32, 32);
12. }
13. 
    
14. void draw(){
15.   background(255);
16.   scroll.display();
17.   scroll.setBackground();
18.   scroll.setHover();
19.   
20.   scroll1.display();
21.   scroll1.setBackground();
22.   scroll1.setHover();
23.   
24.   tint(scroll.calculate(0, 255), scroll1.calculate(0, 255));
25.   image(img, 0, 80);
26. }
27. 
    
29. class Scroller{
30.   float xPos, yPos;
31.   float sliderWidth, sliderHeight;
32.   float sliderMaxBorder, sliderMinBorder;
33.   boolean over;
34.   boolean locked;
35.   float m;
36.   
37.   Scroller(float tempX, float tempY, float tempWidth, 
38.     float tempHeight){
39.       xPos = tempX;
40.       yPos = tempY;
41.       sliderWidth = tempWidth;
42.       sliderHeight = tempHeight;
43.       
44.       sliderMaxBorder = width-sliderWidth;
45.       sliderMinBorder = 0;
46.   }
47.   
48.   void setHover(){
49.     if(overEvent()){
50.       println("Hover = " + over);
51.       over = true;
52.     }
53.     else{
54.       println("Hover = " + over);
55.       over = false;
56.     }
57.     if(mousePressed && over){
58.       println("Clicked = " + locked);
59.       locked = true;
60.     }
61.     else{
62.       println("Clicked = " + locked);
63.       locked = false;
64.     }
65.     if(locked){
66.       xPos = constrain(mouseX-sliderHeight/2, 
67.         sliderMinBorder, sliderMaxBorder);
68.     }
69.   }
70.   
71.   float calculate(float tempMin, float tempMax)
72.   {  
73.     float minValue = tempMin;
74.     float maxValue = tempMax;
75. 
    
76.     float a = getPos() / 100;
77.     float b = maxValue / 100;
78.     float ca = a / b;
79.     float aa = ((getPos() / 10) * ca) * 2;
80.     println(aa);
81.     return aa;
82.   }
83.   
84.   void setBackground(){
85.     fill(80, 80, 80, 150);
86.     //rectMode(CENTER);
87.     rect(0, yPos + sliderHeight/3, width, sliderHeight/3);
88.   }
89.   
90.    boolean overEvent(){
91.     if(mouseX > xPos && mouseX < xPos + sliderWidth &&
92.     mouseY > yPos && mouseY < yPos + sliderHeight){
93.       return true;
94.     }
95.     else{
96.       return false;
97.     }
98.   }
99.   
100.   void display(){
101.     noStroke();
102.     fill(204);
103.     if(over){
104.       fill(0, 0, 0);
105.     }
106.     else{
107.       fill(102, 102, 102);
108.     }
109.     rect(xPos, yPos, sliderHeight, sliderHeight);
110.   }
111.   
112.   float getPos(){
113.     return xPos;
114.   }
115. }