RunningRainbow
// ***********************************************************
// >>start
// >name: RunningRainbow
// >class: Applet
// >Autor: (C) 1996 by Oleg V. Baranovsky.
// >e-mail: oleg@usemb.kiev.ua
// >URL: http://www.usemb.kiev.ua/oleg/
// >Description:
// >>start
// Implements different methods for generation of running rainbow lines
// >>end
// >Classification: Graphics/VisualEffects
// >>end
// ***********************************************************
import java.awt.*;
import java.applet.Applet;
import java.lang.Math;
import java.lang.System;
public class RunningRainbow extends Applet implements Runnable {
int delay;
int shift;
int offset;
double ss, ar, ag, ab, sr, sg ,sb, ar1;
String direction;
String method;
boolean isInvert;
boolean isRunning;
boolean isParams=false;
Thread animatorThread;
Image offImage;
Graphics offGraphics;
public void init() {
isRunning=true;
if (!isParams) getParams();
}
public void getParams() {
String str;
isParams=true;
// How many milliseconds between frames?
str = getParameter("delay");
int fps = (str != null) ? Integer.parseInt(str) : 100;
delay = (fps > 10) ? fps : 100;
// Shift between frames.
str = getParameter("shift");
fps = (str != null) ? Integer.parseInt(str) : 2;
fps = (fps >= 0 && fps < 256) ? fps : 2;
shift = size().width*fps/256;
direction = getParameter("direction");
if (direction == null) direction = new String("left");
str = getParameter("invert");
isInvert = str != null;
method = getParameter("method");
if (method == null) method = new String("none");
if (method.compareTo("gaussian") == 0){
//Now let's get parameters for color generator.
ar = getDoubleParam("ar", 0.);
ag = getDoubleParam("ag", 0.5);
ab = getDoubleParam("ab", 1.);
ar1 = getDoubleParam("ar1", 0.);
if (getParameter("ss") != null) {
ss = getDoubleParam("ss", 0.5);
sr = sg = sb = ss;
} else {
sr = getDoubleParam("sr", 0.5);
sg = getDoubleParam("sg", 0.5);
sb = getDoubleParam("sb", 0.5);
}
sr = sr*sr/2; sg = sg*sg/2; sb = sb*sb/2;
}
}
public double getDoubleParam(String param, double defValue)
{
String str;
double dbl;
str = getParameter(param);
if (str != null) dbl = parseDouble(str); else dbl = defValue;
if (dbl < 0 || dbl > 1) dbl = defValue;
return dbl;
}
public void start() {
if (isRunning) {
if (animatorThread == null) {
animatorThread = new Thread(this);
//getParams();
}
animatorThread.start();
}
}
public void stop() {
animatorThread = null;
}
public boolean mouseDown(Event e, int x, int y) {
if(isRunning) {
isRunning=false;
stop();
} else {
isRunning=true;
start();
}
return true;
}
public void run() {
//Let's put somehow lower than normal priority.
Thread.currentThread().setPriority(3);
if (direction.compareTo("none") == 0) {
offset = shift;
repaint();
return;
}
// Remember the starting time
long startTime = System.currentTimeMillis();
while (Thread.currentThread() == animatorThread) {
// Display the next frame of animation.
repaint();
// Delay depending on how far we are behind.
try {
startTime += delay;
Thread.sleep(Math.max(0, startTime-System.currentTimeMillis()));
} catch (InterruptedException e) {
break;
}
if (direction.compareTo("right") == 0) {
offset-=shift;
if (offset < 0) offset = size().width;
} else
if (direction.compareTo("left") == 0) {
offset+=shift;
if (offset >= size().width) offset = 0;
}
}
}
// Paint the previous frame (if any).
public void paint(Graphics g) {
if (offImage != null) {
g.drawImage(offImage, -offset, 0, this);
g.drawImage(offImage, size().width-offset, 0, this);
}
}
public void update(Graphics g) {
if (offImage == null) createBuffer();
g.drawImage(offImage, -offset, 0, this);
g.drawImage(offImage, size().width-offset, 0, this);
}
public void createBuffer() {
int x;
if (offImage == null) offImage=createImage(size().width, size().height);
offGraphics=offImage.getGraphics();
if (method.compareTo("gaussian") == 0) {
for (x = 0; x < size().width; x++) {
offGraphics.setColor(cg(x));
offGraphics.drawLine(x, 0, x, size().height);
}
} else {
for (x = 0; x < size().width; x++) {
offGraphics.setColor(c(x));
offGraphics.drawLine(x, 0, x, size().height);
}
}
}
public Color c(int x){
if (x >= size().width) x -= size().width;
double y = (double)x * 6. / (double)(size().width);
double r, g, b;
if (y < 1) { r = 1; g = y; b = 0;}
else
if (y < 2) { r = 2.-y; g = 1; b = 0;}
else
if (y < 3) { r = 0; g = 1; b = y-2.0;}
else
if (y < 4) { r = 0; g = 4.0-y; b = 1;}
else
if (y < 5) { r = y-4.0; g = 0; b = 1;}
else { r = 1; g = 0; b = 6.0-y;}
return new Color((float)r, (float)g, (float)b);
}
public Color cg(int x){
while (x >= size().width) {x -= size().width;};
double y = (double)x / (double)(size().width);
double r, g, b;
if (ar1 != 0 && y > 0.5) r = y - ar1; else r = y - ar;
g = y - ag; b = y - ab;
if (sr != 0) r = Math.exp(-r*r/sr); else r = 0;
if (sg != 0) g = Math.exp(-g*g/sg); else g = 0;
if (sb != 0) b = Math.exp(-b*b/sb); else b = 0;
if (isInvert)
return new Color((float)(1-r), (float)(1-g), (float)(1-b));
else
return new Color((float)r, (float)g, (float)b);
}
public double parseDouble(String str) {
Double d = new Double(str);
return d.doubleValue();
}
public String getAppletInfo() {
return "Running Rainbow applet. Copyright (c)1997, by Oleg V. Baranovsky.";
}
public String[][] getParameterInfo() {
String[][] info = {
// Parameter Name Kind of Value Description
{"delay", "Integer", "delay of animation"},
{"shift", "Integer", "shift of animation"},
{"direction", "String", "direction of animation: left or right"},
{"method", "Integer", "method of rainbow rendering: gaussian or trapezoid"},
{"ar", "Double", "mean value of red component"},
{"ag", "Double", "mean value of green component"},
{"ab", "Double", "mean value of blue component"},
{"sr", "Double", "dispersion of red component"},
{"sg", "Double", "dispersion of green component"},
{"sb", "Double", "dispersion of blue component"},
};
return info;
}
}
Back to the RunningRainbow applet page.
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