mirror of
https://github.com/scratchfoundation/paper.js.git
synced 2024-12-28 17:02:24 -05:00
132 lines
4.8 KiB
HTML
132 lines
4.8 KiB
HTML
<!DOCTYPE html>
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<html>
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<head>
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<meta charset="UTF-8">
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<title>Meta Balls</title>
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<link rel="stylesheet" href="../css/style.css">
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<script type="text/javascript" src="../../dist/paper-full.js"></script>
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<script type="text/paperscript" canvas="canvas">
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// Ported from original Metaball script by SATO Hiroyuki
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// http://park12.wakwak.com/~shp/lc/et/en_aics_script.html
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project.currentStyle = {
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fillColor: 'black'
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};
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var ballPositions = [[255, 129], [610, 73], [486, 363],
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[117, 459], [484, 726], [843, 306], [789, 615], [1049, 82],
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[1292, 428], [1117, 733], [1352, 86], [92, 798]];
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var handle_len_rate = 2.4;
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var circlePaths = [];
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var radius = 50;
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for (var i = 0, l = ballPositions.length; i < l; i++) {
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var circlePath = new Path.Circle({
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center: ballPositions[i],
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radius: 50
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});
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circlePaths.push(circlePath);
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}
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var largeCircle = new Path.Circle({
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center: [676, 433],
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radius: 100
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});
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circlePaths.push(largeCircle);
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function onMouseMove(event) {
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largeCircle.position = event.point;
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generateConnections(circlePaths);
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}
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var connections = new Group();
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function generateConnections(paths) {
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// Remove the last connection paths:
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connections.removeChildren();
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for (var i = 0, l = paths.length; i < l; i++) {
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for (var j = i - 1; j >= 0; j--) {
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var path = metaball(paths[i], paths[j], 0.5, handle_len_rate, 300);
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if (path) {
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connections.appendTop(path);
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path.removeOnMove();
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}
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}
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}
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}
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generateConnections(circlePaths);
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// ---------------------------------------------
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function metaball(ball1, ball2, v, handle_len_rate, maxDistance) {
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var center1 = ball1.position;
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var center2 = ball2.position;
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var radius1 = ball1.bounds.width / 2;
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var radius2 = ball2.bounds.width / 2;
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var pi2 = Math.PI / 2;
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var d = center1.getDistance(center2);
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var u1, u2;
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if (radius1 == 0 || radius2 == 0)
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return;
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if (d > maxDistance || d <= Math.abs(radius1 - radius2)) {
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return;
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} else if (d < radius1 + radius2) { // case circles are overlapping
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u1 = Math.acos((radius1 * radius1 + d * d - radius2 * radius2) /
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(2 * radius1 * d));
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u2 = Math.acos((radius2 * radius2 + d * d - radius1 * radius1) /
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(2 * radius2 * d));
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} else {
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u1 = 0;
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u2 = 0;
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}
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var angle1 = (center2 - center1).getAngleInRadians();
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var angle2 = Math.acos((radius1 - radius2) / d);
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var angle1a = angle1 + u1 + (angle2 - u1) * v;
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var angle1b = angle1 - u1 - (angle2 - u1) * v;
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var angle2a = angle1 + Math.PI - u2 - (Math.PI - u2 - angle2) * v;
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var angle2b = angle1 - Math.PI + u2 + (Math.PI - u2 - angle2) * v;
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var p1a = center1 + getVector(angle1a, radius1);
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var p1b = center1 + getVector(angle1b, radius1);
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var p2a = center2 + getVector(angle2a, radius2);
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var p2b = center2 + getVector(angle2b, radius2);
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// define handle length by the distance between
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// both ends of the curve to draw
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var totalRadius = (radius1 + radius2);
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var d2 = Math.min(v * handle_len_rate, (p1a - p2a).length / totalRadius);
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// case circles are overlapping:
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d2 *= Math.min(1, d * 2 / (radius1 + radius2));
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radius1 *= d2;
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radius2 *= d2;
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var path = new Path({
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segments: [p1a, p2a, p2b, p1b],
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style: ball1.style,
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closed: true
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});
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var segments = path.segments;
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segments[0].handleOut = getVector(angle1a - pi2, radius1);
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segments[1].handleIn = getVector(angle2a + pi2, radius2);
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segments[2].handleOut = getVector(angle2b - pi2, radius2);
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segments[3].handleIn = getVector(angle1b + pi2, radius1);
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return path;
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}
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// ------------------------------------------------
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function getVector(radians, length) {
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return new Point({
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// Convert radians to degrees:
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angle: radians * 180 / Math.PI,
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length: length
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});
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}
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</script>
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</head>
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<body>
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<canvas id="canvas" resize></canvas>
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</body>
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</html>
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