Files
processing4/java/examples/Topics/Interaction/Follow3/applet/Follow3.java
benfry eb64b2d4fc
2011-01-26 19:22:19 +00:00

65 lines
1.3 KiB
Java

import processing.core.*;
import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.text.*;
import java.util.*;
import java.util.zip.*;
import java.util.regex.*;
public class Follow3 extends PApplet {
/**
* Follow 3.
* Based on code from Keith Peters (www.bit-101.com).
*
* A segmented line follows the mouse. The relative angle from
* each segment to the next is calculated with atan2() and the
* position of the next is calculated with sin() and cos().
*/
float[] x = new float[20];
float[] y = new float[20];
float segLength = 9;
public void setup() {
size(200, 200);
smooth();
strokeWeight(5);
stroke(0, 100);
}
public void draw() {
background(226);
dragSegment(0, mouseX, mouseY);
for(int i=0; i<x.length-1; i++) {
dragSegment(i+1, x[i], y[i]);
}
}
public void dragSegment(int i, float xin, float yin) {
float dx = xin - x[i];
float dy = yin - y[i];
float angle = atan2(dy, dx);
x[i] = xin - cos(angle) * segLength;
y[i] = yin - sin(angle) * segLength;
segment(x[i], y[i], angle);
}
public void segment(float x, float y, float a) {
pushMatrix();
translate(x, y);
rotate(a);
line(0, 0, segLength, 0);
popMatrix();
}
static public void main(String args[]) {
PApplet.main(new String[] { "Follow3" });
}
}