topical media & game development
#javascript-processing-example-topic-motion-bounce.htm / htm
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<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>Bounce</h2>
<p>When the shape hits the edge of the window, it reverses its direction.</p>
<p><a href="http://processing.org/learning/topics/bounce.html"><b>Original Processing.org Example:</b> Bounce</a><br>
<script type="application/processing">
int wsize = 60; // Width of the shape
float xpos, ypos; // Starting position of shape
float xspeed = 2.8; // Speed of the shape
float yspeed = 2.2; // Speed of the shape
int xdirection = 1; // Left or Right
int ydirection = 1; // Top to Bottom
void setup()
{
size(200, 200);
noStroke();
frameRate(30);
smooth();
// Set the starting position of the shape
xpos = width/2;
ypos = height/2;
}
void draw()
{
background(102);
// Update the position of the shape
xpos = xpos + ( xspeed * xdirection );
ypos = ypos + ( yspeed * ydirection );
// Test to see if the shape exceeds the boundaries of the screen
// If it does, reverse its direction by multiplying by -1
if (xpos > width-wsize || xpos < 0) {
xdirection *= -1;
}
if (ypos > height-wsize || ypos < 0) {
ydirection *= -1;
}
// Draw the shape
ellipse(xpos+wsize/2, ypos+wsize/2, wsize, wsize);
}
</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 size = 60; // Width of the shape
float xpos, ypos; // Starting position of shape
float xspeed = 2.8; // Speed of the shape
float yspeed = 2.2; // Speed of the shape
int xdirection = 1; // Left or Right
int ydirection = 1; // Top to Bottom
void setup()
{
size(200, 200);
noStroke();
frameRate(30);
smooth();
// Set the starting position of the shape
xpos = width/2;
ypos = height/2;
}
void draw()
{
background(102);
// Update the position of the shape
xpos = xpos + ( xspeed * xdirection );
ypos = ypos + ( yspeed * ydirection );
// Test to see if the shape exceeds the boundaries of the screen
// If it does, reverse its direction by multiplying by -1
if (xpos > width-size || xpos < 0) {
xdirection *= -1;
}
if (ypos > height-size || ypos < 0) {
ydirection *= -1;
}
// Draw the shape
ellipse(xpos+size/2, ypos+size/2, size, size);
}</pre>
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(C) Æliens
20/2/2008
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