openjscad-aurora-webapp

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// title: Four to three (sides)
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// author: Eduard Bespalov
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// license: MIT License
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// description: testing solidFromSlices()
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function getParameterDefinitions() {
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  return [
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	{ name: 'radius', caption: 'Radius:', type: 'float', default: 10 },
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	{ name: 'height', caption: 'Height:', type: 'float', default: 35 },
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	{ name: 'twist', caption: 'Twist:', type: 'int', default: 90}
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  ];
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}
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function main(params) {
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	var thing = thingTwisted(params.radius, params.height, params.twist);
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	return thing;
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}
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function thingTwisted(radius, height, twistangle) {
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  twistangle = twistangle || 0;
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	var cag = CAG.fromPoints([
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		[-radius, -radius, 0],
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		[radius, -radius, 0],
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		[radius, radius, 0]
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	]).expand(2, CSG.defaultResolution2D);
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	var flatBottom = CSG.Polygon.createFromPoints(
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		cag.getOutlinePaths()[0].points
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	);
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  var thing = flatBottom.solidFromSlices({
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	numslices: height
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	,callback: function(t) {
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		var coef = 1 - t;
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		if (coef < 0.01) coef = 0.01;//must not collapse polygon
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		var h = height * t;
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		var cag = CAG.fromPoints([
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			[-radius, -radius, h],
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			[radius, -radius, h],
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	 		[radius * coef, radius, h],
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			[-radius * coef, radius, h]
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		]).expand(2, CSG.defaultResolution2D)
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			.rotate([0,0,0], [0,0,1], twistangle * t);
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		return CSG.Polygon.createFromPoints(
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			cag.getOutlinePaths()[0].points
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		).translate([0, 0, h]);
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	}
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  });
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   return thing;
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}
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