CODEWITHSUNDEEP
androidcolors
Deepak Sharma
Deepak Sharma

Reputation: 1137

Find scale between three colors

I am not a Android developer, but my team members required the same thing I did on the web. I required a function to which I pass any three colors (e.g. red,blue,green), and I will pass a count, e.g. 100.

Definition of function

function getColorArray(mincolor,midcolor,maxcolor,100){
    return colorarray;
}

When I have to call function:

getColorArray(red,yellow,green,100)

So it will give a array of 100 colors from a red,blue,green color scale.

I did it in Javascript. Here is the fiddle link.

I want the same output in Android.

Upvotes: 2

Views: 180

Answers (1)

Janez Kuhar
Janez Kuhar

Reputation: 4266

This code does a simple line interpolation (c1 - c2, c2 - c3) . Your example JS code has richer options than this simple example (non linear interpolations), but I think this should help you get started.

You should probably define some custom colors if you're going to let the users name the colors - the default range of system colors is pretty limited (at least with java.awt.Color predifined colors, that is).

import java.awt.*;
import javax.swing.*;
import java.lang.reflect.Field;

public class ColorTest {
    public static void main(String[] args) {
        int n = args.length > 0 ? Integer.parseInt(args[0]) : 5;
        Color[] test = getColorArray("red", "green", "blue", n);
        for(Color c : test) {
            System.out.println(c);
        }
    }
    
    public static Color[] getColorArray(String c1, String c2, String c3, int n) {
        Color[] inputColors = new Color[3];
        try {
            Field field1 = Color.class.getField(c1);
            Field field2 = Color.class.getField(c2);
            Field field3 = Color.class.getField(c3);
        
            inputColors[0] = (Color) field1.get(null); 
            inputColors[1] = (Color) field2.get(null);
            inputColors[2] = (Color) field3.get(null);
        } catch (Exception e) {
            System.err.println("One of the color values is not defined!");
            System.err.println(e.getMessage());
            return null;
        }
    
        Color[] result = new Color[n];
    
        int[] c1RGB = { inputColors[0].getRed(), inputColors[0].getGreen(), inputColors[0].getBlue() };
        int[] c2RGB = { inputColors[1].getRed(), inputColors[1].getGreen(), inputColors[1].getBlue() };
        int[] c3RGB = { inputColors[2].getRed(), inputColors[2].getGreen(), inputColors[2].getBlue() };
        int[] tmpRGB = new int[3];
    
        tmpRGB[0] = c2RGB[0] - c1RGB[0];
        tmpRGB[1] = c2RGB[1] - c1RGB[1];
        tmpRGB[2] = c2RGB[2] - c1RGB[2];
        float mod = n/2.0f; 
        for (int i = 0; i < n/2; i++) {
            result[i] = new Color(
                (int) (c1RGB[0] + i/mod*tmpRGB[0]) % 256, 
                (int) (c1RGB[1] + i/mod*tmpRGB[1]) % 256,
                (int) (c1RGB[2] + i/mod*tmpRGB[2]) % 256
            );
        }
    
        tmpRGB[0] = c3RGB[0] - c2RGB[0];
        tmpRGB[1] = c3RGB[1] - c2RGB[1];
        tmpRGB[2] = c3RGB[2] - c2RGB[2];
        for (int i = 0; i < n/2 + n%2; i++) {
            result[i+n/2] = new Color(
                (int) (c2RGB[0] + i/mod*tmpRGB[0]) % 256, 
                (int) (c2RGB[1] + i/mod*tmpRGB[1]) % 256,
                (int) (c2RGB[2] + i/mod*tmpRGB[2]) % 256
            );
        }
    
        return result;
    }
}

Upvotes: 1

Related Questions