82 lines
1.2 KiB
JavaScript
82 lines
1.2 KiB
JavaScript
/**
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* @author zz85 / http://www.lab4games.net/zz85/blog
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*
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* Bezier Curves formulas obtained from
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* http://en.wikipedia.org/wiki/Bézier_curve
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*/
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function CatmullRom( t, p0, p1, p2, p3 ) {
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var v0 = ( p2 - p0 ) * 0.5;
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var v1 = ( p3 - p1 ) * 0.5;
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var t2 = t * t;
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var t3 = t * t2;
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return ( 2 * p1 - 2 * p2 + v0 + v1 ) * t3 + ( - 3 * p1 + 3 * p2 - 2 * v0 - v1 ) * t2 + v0 * t + p1;
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}
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//
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function QuadraticBezierP0( t, p ) {
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var k = 1 - t;
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return k * k * p;
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}
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function QuadraticBezierP1( t, p ) {
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return 2 * ( 1 - t ) * t * p;
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}
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function QuadraticBezierP2( t, p ) {
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return t * t * p;
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}
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function QuadraticBezier( t, p0, p1, p2 ) {
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return QuadraticBezierP0( t, p0 ) + QuadraticBezierP1( t, p1 ) +
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QuadraticBezierP2( t, p2 );
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}
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//
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function CubicBezierP0( t, p ) {
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var k = 1 - t;
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return k * k * k * p;
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}
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function CubicBezierP1( t, p ) {
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var k = 1 - t;
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return 3 * k * k * t * p;
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}
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function CubicBezierP2( t, p ) {
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return 3 * ( 1 - t ) * t * t * p;
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}
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function CubicBezierP3( t, p ) {
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return t * t * t * p;
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}
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function CubicBezier( t, p0, p1, p2, p3 ) {
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return CubicBezierP0( t, p0 ) + CubicBezierP1( t, p1 ) + CubicBezierP2( t, p2 ) +
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CubicBezierP3( t, p3 );
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}
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export { CatmullRom, QuadraticBezier, CubicBezier };
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