renderer usecka

package ukol1;

import java.awt.Color;
import java.awt.event.*;

import fim.utils.Application;
import fim.utils.Console;

@SuppressWarnings("serial")
public class Pixel extends Application {
    private int x, y;

    private Renderer r = new Renderer(img);

    public void start() {
        img = out.getCanvas().getImage();
        out.switchView(Console.VIEW_GRAPH);
        r.drawPixel(10, 20, 0xff0000);

        out.getCanvas().addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent ev) {
                x = ev.getX();
                y = ev.getY();
            }

            public void mouseReleased(MouseEvent ev) {
                r.drawLine(x, y, ev.getX(), ev.getY(), 0x00FF00);
                out.repaint();
            }
        });

    }

    public static void main(String[] args) {
        new Pixel().start();
    }

}

/* --------------------------------------------------------- */

package ukol1;

import java.awt.image.BufferedImage;

public class Renderer {
    private BufferedImage img;

    public Renderer(BufferedImage img) {
        this.img = img;
    }

    public void drawPixel(int x, int y, int barva) {
        if (x > 0 && x < img.getWidth()) {
            if (y > 0 && y < img.getHeight()) {
                img.setRGB(x, y, barva);
            }
        }
    }

    public void drawLine(int x1, int y1, int x2, int y2, int barva) {

        int x;
        int y;
        float k, q;

        if (Math.abs(x2 - x1) > Math.abs(y2 - y1)) {

            if (x1 > x2) {
                int pom = x2;
                x2 = x1;
                x1 = pom;
                pom = y2;
                y2 = y1;
                y1 = pom;
            }

            int dx = x2 - x1;
            int dy = y2 - y1;

            k = (y1 - y2) / (float) (y2 - y1);
            q = y1 - k * x1;

            for (x = x1; x <= x2; x++) {
                y = Math.round(k * x + q);
                drawPixel(x, y, 0x00FF00);
            }

        } else {

            if (y1 > y2) {
                int pom = x2;
                x2 = x1;
                x1 = pom;
                pom = y2;
                y2 = y1;
                y1 = pom;
            }
            k = (float)(x1 - x2) / (y1 - y2);
            q = x2 - k * y2;

            for (y = y1; y <= y2; y++) {
                x = Math.round(k * y + q);
                drawPixel(x, y, 0x00FF00);
            }
        }


    }

}