topical media & game development
#javascript-processing-example-topic-drawing-scribbleplotter.htm / htm
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<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>ScribblePlotter</h2>
<p>by Ira Greenberg.
Using 2-dimensional arrays, record end points
and replot scribbles between points.</p>
<p><a href="http://processing.org/learning/topics/scribbleplotter.html"><b>Original Processing.org Example:</b> ScribblePlotter</a><br>
<script type="application/processing">
// some scribble style constants that control
// how the scribble plotting works
int SCRIBBLE = 0;
int HATCHING = 1;
void setup(){
size(200, 200);
background(0);
// create arrays to hold x, y coords
float[]x = new float[4];
float[]y = new float[4];
// create a convenient 2-dimensional
// array to hold x, y arrays
float[][]xy = {x, y};
// record points
// x positions
xy[0][0] = 25;
xy[0][1] = 175;
xy[0][2] = 175;
xy[0][3] = 25;
// y positions
xy[1][0] = 25;
xy[1][1] = 25;
xy[1][2] = 175;
xy[1][3] = 175;
// call plotting function
makeRect(xy);
}
void makeRect(float[][]pts){
stroke(255);
smooth();
// scribble variables, that get passed as arguments to the scribble function
int steps = 100;
float scribVal = 3.0;
for (int i=0; i< pts[0].length; i++){
//plots vertices
strokeWeight(5);
point(pts[0][i], pts[1][i]);
// call scribble function
strokeWeight(.5);
if (i>0){
scribble(pts[0][i], pts[1][i], pts[0][i-1], pts[1][i-1], steps, scribVal, SCRIBBLE);
}
if (i== pts[0].length-1){
// show some hatching between last 2 points
scribble(pts[0][i], pts[1][i], pts[0][0], pts[1][0], steps, scribVal*2, HATCHING);
}
}
}
/*
scribble function plots lines between end points,
determined by steps and scribVal arguments.
2 styles are available: SCRIBBLE and HATCHING, which
are interestingly only dependent on parentheses
placement in the line() function calls.
*/
void scribble(float x1, float y1, float x2, float y2, int steps, float scribVal, int style){
float xStep = (x2-x1)/steps;
float yStep = (y2-y1)/steps;
for (int i = 0; i<steps; i++){
if(style == SCRIBBLE){
if (i<steps-1){
line(x1, y1, x1+=xStep+random(-scribVal, scribVal), y1+=yStep+random(-scribVal, scribVal));
}
else {
// extra line needed to attach line back to point- not necessary in HATCHING style
line(x1, y1, x2, y2);
}
}
else if (style == HATCHING){
line(x1, y1, (x1+=xStep)+random(-scribVal, scribVal), (y1+=yStep)+random(-scribVal, scribVal));
}
}
}
</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>
// some scribble style constants that control
// how the scribble plotting works
int SCRIBBLE = 0;
int HATCHING = 1;
void setup(){
size(200, 200);
background(0);
// create arrays to hold x, y coords
float[]x = new float[4];
float[]y = new float[4];
// create a convenient 2-dimensional
// array to hold x, y arrays
float[][]xy = {x, y};
// record points
// x positions
xy[0][0] = 25;
xy[0][1] = 175;
xy[0][2] = 175;
xy[0][3] = 25;
// y positions
xy[1][0] = 25;
xy[1][1] = 25;
xy[1][2] = 175;
xy[1][3] = 175;
// call plotting function
makeRect(xy);
}
void makeRect(float[][]pts){
stroke(255);
smooth();
// scribble variables, that get passed as arguments to the scribble function
int steps = 100;
float scribVal = 3.0;
for (int i=0; i< pts[0].length; i++){
//plots vertices
strokeWeight(5);
point(pts[0][i], pts[1][i]);
// call scribble function
strokeWeight(.5);
if (i>0){
scribble(pts[0][i], pts[1][i], pts[0][i-1], pts[1][i-1], steps, scribVal, SCRIBBLE);
}
if (i== pts[0].length-1){
// show some hatching between last 2 points
scribble(pts[0][i], pts[1][i], pts[0][0], pts[1][0], steps, scribVal*2, HATCHING);
}
}
}
/*
scribble function plots lines between end points,
determined by steps and scribVal arguments.
2 styles are available: SCRIBBLE and HATCHING, which
are interestingly only dependent on parentheses
placement in the line() function calls.
*/
void scribble(float x1, float y1, float x2, float y2, int steps, float scribVal, int style){
float xStep = (x2-x1)/steps;
float yStep = (y2-y1)/steps;
for (int i = 0; i<steps; i++){
if(style == SCRIBBLE){
if (i<steps-1){
line(x1, y1, x1+=xStep+random(-scribVal, scribVal), y1+=yStep+random(-scribVal, scribVal));
}
else {
// extra line needed to attach line back to point- not necessary in HATCHING style
line(x1, y1, x2, y2);
}
}
else if (style == HATCHING){
line(x1, y1, (x1+=xStep)+random(-scribVal, scribVal), (y1+=yStep)+random(-scribVal, scribVal));
}
}
}</pre>
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(C) Æliens
20/2/2008
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