import org.newdawn.slick.AppGameContainer;
import org.newdawn.slick.BasicGame;
import org.newdawn.slick.Color;
import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.Image;
import org.newdawn.slick.SlickException;


public class GameTest2 extends BasicGame {


    public GameTest2() {
        super("slick test");
    }

    public static void main(String[] args) throws SlickException {
        new AppGameContainer(new GameTest2(), 800, 600, false).start();
    }

    private Image sv, hue;
    private Color hueColor = new Color(Color.red);
    private Color output = new Color(Color.red);
    private boolean over = false;
    private float[] hsv = { 0f, 1f, 1f };
    private float hueVal = 1f;

    public void init(GameContainer c) throws SlickException {
        c.setShowFPS(false);
        //c.setClearEachFrame(false);
        c.getGraphics().setBackground(Color.lightGray);

        sv = new Image("res/svPane.png");
        hue = new Image("res/huePane.png");
    }

    public void render(GameContainer c, Graphics g) throws SlickException {
        g.setColor(hueColor);
        g.fillRect(50, 50, sv.getWidth(), sv.getHeight());
        sv.draw(50, 50);
        hue.draw(225, 50);

        if (over) {
            g.setColor(output);
            g.fillRect(50, 250, 50, 50);
        }
    }

    public void update(GameContainer c, int delta) throws SlickException {
        int mx = c.getInput().getMouseX();
        int my = c.getInput().getMouseY();
        over = false;
        if (mx >= 225 && mx <= 225+hue.getWidth() && my >= 50 && my <=50+hue.getHeight()) {
            float perc = 1 - ((my-50) / (float)hue.getHeight());
            hsv[0] = hueVal = perc * 360;
            hsv[1] = hsv[2] = 1f;
            HSVtoRGB(hsv, hueColor);
        } else if (mx >= 50 && mx <= 50+sv.getWidth() && my >= 50 && my <= 50+sv.getHeight()) {
            float sat = ((mx-50) / (float)sv.getWidth());
            float val = 1 - ((my-50) / (float)sv.getHeight());
            hsv[0] = hueVal;
            hsv[1] = sat;
            hsv[2] = val;
            //System.out.println();
            HSVtoRGB(hsv, output);
            over = true;
        }
    }



    public static void HSVtoRGB(float[] hsv, Color rgbOut) {
        //http://www.cs.rit.edu/~ncs/color/t_convert.html
        float h=hsv[0], s=hsv[1], v=hsv[2];

        int i;
        float r, g, b;
        float f, p, q, t;
        if (s==0) {
            // achromatic (grey)
            r = g = b = v;
        } else {
            h /= 60; // sector 0 to 5
            i = (int)h;
            f = h - i; // factorial part of h
            p = v * (1 - s);
            q = v * (1 - s * f);
            t = v * (1 - s * (1-f));
            switch (i) {
                case 0:
                    r = v;
                    g = t;
                    b = p;
                    break;
                case 1:
                    r = q;
                    g = v;
                    b = p;
                    break;
                case 2:
                    r = p;
                    g = v;
                    b = t;
                    break;
                case 3:
                    r = p;
                    g = q;
                    b = v;
                    break;
                case 4:
                    r = t;
                    g = p;
                    b = v;
                    break;
                default:
                    r = v;
                    g = p;
                    b = q;
                    break;
            }
        }
        rgbOut.r = r;
        rgbOut.g = g;
        rgbOut.b = b;
    }
}