/**
 * GameLib.D3.API.Geometry.Buffer.Parametric
 * @param apiGeometry
 * @param generatorFn(u,v) => returns Vector3, u and v is values between 0 and 1
 * @param slices
 * @param stacks
 * @constructor
 */
GameLib.D3.API.Geometry.Buffer.Parametric = function(
    apiGeometry,
    generatorFn,
    slices,
    stacks
) {

    if (GameLib.Utils.UndefinedOrNull(apiGeometry)) {
        apiGeometry = {
            geometryType: GameLib.D3.API.Geometry.GEOMETRY_TYPE_BUFFER_PARAMETRIC
        };
    }

    if (GameLib.Utils.UndefinedOrNull(apiGeometry.geometryType)) {
        apiGeometry.geometryType = GameLib.D3.API.Geometry.GEOMETRY_TYPE_BUFFER_PARAMETRIC;
    }

    if (GameLib.Utils.UndefinedOrNull(generatorFn)) {
        generatorFn = '';
    }
    this.generatorFn = generatorFn;

    if (GameLib.Utils.UndefinedOrNull(slices)) {
        slices = 20;
    }
    this.slices = slices;

    if (GameLib.Utils.UndefinedOrNull(stacks)) {
        stacks = 20;
    }
    this.stacks = stacks;

    GameLib.D3.API.Geometry.Buffer.call(
        this,
        apiGeometry,
        apiGeometry.attributes,
        apiGeometry.drawRange,
        apiGeometry.groups,
        apiGeometry.index,
        apiGeometry.morphAttributes
    );
};

GameLib.D3.API.Geometry.Buffer.Parametric.prototype = Object.create(GameLib.D3.API.Geometry.Buffer.prototype);
GameLib.D3.API.Geometry.Buffer.Parametric.prototype.constructor = GameLib.D3.API.Geometry.Buffer.Parametric;