Keskustelu: Ohjelmointikysymykset: Java: Kuvat kääntymään(java)

import java.awt.*;
import javax.swing.*;
import java.awt.image.*;
import java.awt.event.*;

public class Rotor extends Canvas {

  private int[] screen;
  private int[] pixels1;
  // 1024*sin values
  private int[] sins = new int[256];
  // 1024*cos values
  private int[] coss = new int[256];


  private Image screenImage;

  private MemoryImageSource mis;

  /**
   * Picture name
   */
  private String sFile1 = "kuva.png";

  private int w, h;
  private int n;

  private int alpha = 0;
  private byte flip = 1;
  public Rotor() {
    Image image = new ImageIcon(sFile1).getImage();
    w = image.getWidth(this);
    h = image.getHeight(this);
    n = w*h;
    pixels1 = getPixels(image);

    screen = new int[w*h];

    mis=new MemoryImageSource(w,h,ColorModel.getRGBdefault(),screen,0,w);
    mis.setAnimated(true);
    mis.setFullBufferUpdates(true);
    screenImage=createImage(mis);
    initTrig();
  }

  private void initTrig() {
    for (int i = 0; i < 256; i++) {
      sins[i] = (int)(1024*Math.sin(  i*Math.PI / 128 ));
      coss[i] = (int)(1024*Math.cos(  i*Math.PI / 128 ));

    }
  }

  public int[] getPixels(Image image) {
    int[] pixels = new int[w*h];

    PixelGrabber pg
      = new PixelGrabber(image,0,0,w,h,pixels,0,w);
    try {
      pg.grabPixels();
    }
    catch (InterruptedException e) {}
    return pixels;
  }

  public void paint(Graphics g) {
    g.drawImage(screenImage,0,0,this);
  }

  public void update(Graphics g) {
    paint(g);
  }

  int db = 1;
  public void render() {
    alpha += 1;

    alpha = alpha &0xff;
    int offs = 0;
    int minY = (-h>>1);
    int maxY = h+minY;
    int minX = -w>>1;
    int maxX = w+minX;
    int n = w*h;

    int cs = coss[alpha];
    int ss = sins[alpha];

    for (int y = minY; y < maxY; y++) {
      for (int x = minX; x < maxX; x++) {
                                //>>10 == /1024 (sin/cos rounding)
	int x1 = ((cs*x  + (ss*y))>>10) -minX;
	int y1 = ((-ss*x + (cs*y))>>10) -minY;

        if (x1 < 0) do { x1 += w; } while(x1 < 0);
        else if (x1 >= w) do { x1 -= w; } while(x1 >=w);
        if (y1 < 0) do { y1 += h; } while(y1 < 0);
        else if (y1 >= h) do { y1 -= h; } while(y1 >=h);
        screen[ offs++ ] = pixels1[y1*w+x1];
      }

    }
  }

  public void nextFrame() {
    render();
    mis.newPixels(0, 0, w, h);
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame("Rotor");
    Rotor f = new Rotor();
    frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    frame.setSize(800,600);

    frame.getContentPane().add(f);
    frame.show();

    while(frame.isShowing()) {
      f.nextFrame();

      try {
      	Thread.sleep(20);
      }catch(Exception e) {return;}
    }

  }
}