#javascript-processing-example-topic-interaction-reach2.htm / htm
<!DOCTYPE html> <html><head> <script src="javascript-processing-example-processing.js"></script> <script src="javascript-processing-example-init.js"></script> <link rel="stylesheet" href="javascript-processing-example-style.css"> </head><body><h1><a href="http://ejohn.org/blog/processingjs/">Processing.js</a></h1> <h2>Reach2</h2> <p>Based on code from Keith Peters (www.bit-101.com) The arm follows the position of the mouse by calculating the angles with atan2().</p> <p><a href="http://processing.org/learning/topics/reach2.html"><b>Original Processing.org Example:</b> Reach2</a><br> <script type="application/processing"> int numSegments = 10; float[] x = new float[numSegments]; float[] y = new float[numSegments]; float[] angle = new float[numSegments]; float segLength = 20; float targetX, targetY; void setup() { size(200, 200); smooth(); strokeWeight(20.0); stroke(0, 100); x[x.length-1] = 0; // Set base x-coordinate y[x.length-1] = height; // Set base y-coordinate } void draw() { background(226); reachSegment(0, mouseX, mouseY); for(int i=1; i<numSegments; i++) { reachSegment(i, targetX, targetY); } for(int i=x.length-1; i>=1; i--) { positionSegment(i, i-1); } for(int i=0; i<x.length; i++) { segment(x[i], y[i], angle[i], (i+1)*2); } } void positionSegment(int a, int b) { x[b] = x[a] + cos(angle[a]) * segLength; y[b] = y[a] + sin(angle[a]) * segLength; } void reachSegment(int i, float xin, float yin) { float dx = xin - x[i]; float dy = yin - y[i]; angle[i] = atan2(dy, dx); targetX = xin - cos(angle[i]) * segLength; targetY = yin - sin(angle[i]) * segLength; } void segment(float x, float y, float a, float sw) { strokeWeight(sw); pushMatrix(); translate(x, y); rotate(a); line(0, 0, segLength, 0); popMatrix(); } </script><canvas width="200" height="200"></canvas></p> <div style="overflow: hidden; height: 0px; width: 0px;"></div> <pre><b>// All Examples Written by <a href="http://reas.com/">Casey Reas</a> and <a href="http://benfry.com/">Ben Fry</a> // unless otherwise stated.</b> int numSegments = 10; float[] x = new float[numSegments]; float[] y = new float[numSegments]; float[] angle = new float[numSegments]; float segLength = 20; float targetX, targetY; void setup() { size(200, 200); smooth(); strokeWeight(20.0); stroke(0, 100); x[x.length-1] = 0; // Set base x-coordinate y[x.length-1] = height; // Set base y-coordinate } void draw() { background(226); reachSegment(0, mouseX, mouseY); for(int i=1; i<numSegments; i++) { reachSegment(i, targetX, targetY); } for(int i=x.length-1; i>=1; i--) { positionSegment(i, i-1); } for(int i=0; i<x.length; i++) { segment(x[i], y[i], angle[i], (i+1)*2); } } void positionSegment(int a, int b) { x[b] = x[a] + cos(angle[a]) * segLength; y[b] = y[a] + sin(angle[a]) * segLength; } void reachSegment(int i, float xin, float yin) { float dx = xin - x[i]; float dy = yin - y[i]; angle[i] = atan2(dy, dx); targetX = xin - cos(angle[i]) * segLength; targetY = yin - sin(angle[i]) * segLength; } void segment(float x, float y, float a, float sw) { strokeWeight(sw); pushMatrix(); translate(x, y); rotate(a); line(0, 0, segLength, 0); popMatrix(); }</pre> </body></html>
(C) Æliens 20/2/2008
You may not copy or print any of this material without explicit permission of the author or the publisher. In case of other copyright issues, contact the author.