three/src/math/interpolants/LinearInterpolant.js

JavaScript 3D library

/**
 * @author tschw
 */

THREE.LinearInterpolant = function(
		parameterPositions, sampleValues, sampleSize, resultBuffer ) {

	THREE.Interpolant.call(
			this, parameterPositions, sampleValues, sampleSize, resultBuffer );

};

THREE.LinearInterpolant.prototype =
		Object.assign( Object.create( THREE.Interpolant.prototype ), {

	constructor: THREE.LinearInterpolant,

	interpolate_: function( i1, t0, t, t1 ) {

		var result = this.resultBuffer,
			values = this.sampleValues,
			stride = this.valueSize,

			offset1 = i1 * stride,
			offset0 = offset1 - stride,

			weight1 = ( t - t0 ) / ( t1 - t0 ),
			weight0 = 1 - weight1;

		for ( var i = 0; i !== stride; ++ i ) {

			result[ i ] =
					values[ offset0 + i ] * weight0 +
					values[ offset1 + i ] * weight1;

		}

		return result;

	}

} );