function [g_, attributes_, batchMethods_] = dXgameHID(num_objects)
% function [g_, attributes_, batchMethods_] = dXgameHID(num_objects)
%
% Constructor method for class dXgameHID
%   DotsX interface to USB HID gamepads
%
% Input:
%   num_objects     ... ignored -- always creates just one
%
% Output:
%   g_              ... created object
%   attributes_     ... default object attributes
%   batchMethods_   ... methods that can be run in a batch (e.g., draw)

% Copyright 2007 Benjamin Heasly
%   University of Pennsylvania

global ROOT_STRUCT

% look for mex function
available = exist('HIDx') == 3;

% return empty matrix if not available, which
% will automatically remove gameHID devices from the ui queue
% if called from rInit
if isfield(ROOT_STRUCT, 'dXgameHID') || ~available
    g_            = [];
    attributes_   = [];
    batchMethods_ = [];
    return
end

% how to find compatible device
HIDCriteria.usageName = 'GamePad';

% default channelizer.
%   use raw values from each element
%   feebly guess at the number of elements: 8
n = 8;
[HIDChannelizer(1:n).gain] = deal(1);
[HIDChannelizer(1:n).offset] = deal(0);
[HIDChannelizer(1:n).high] = deal(nan);
[HIDChannelizer(1:n).low] = deal(nan);
[HIDChannelizer(1:n).delta] = deal(0);
[HIDChannelizer(1:n).freq] = deal(1);

% default object attributes
attributes = { ...
    % name          type        ranges(?)	default
    'available',	'boolean',  [],         available; ...
    'active',       'boolean',  [],         false; ...
    'FIRAdataType', 'string',   [],         'gameHIDData'; ...
    'HIDClass',     'string',   [],         'dXgameHID'; ...
    'HIDCriteria',  'struct',   [],         HIDCriteria; ...
    'HIDChannelizer','struct',  [],         HIDChannelizer; ...
    'HIDIndex',     'scalar',   [],         nan; ...
    'HIDDeviceInfo','struct',   [],         []; ...
    'HIDElementsInfo','struct', [],         []; ...
    'mappings',     'cell',     [],         {};...
    'offsetTime',   'auto',     [],         0; ...
    'default',      'auto',     [],         []; ...
    'other',        'auto',     [],         []; ...
    'checkList',    'auto',     [],         []; ...
    'checkRet',     'auto',     [],         []; ...
    'values',       'auto',     [],         []; ...
    'recentVal',    'auto',     [],         1};

% make an array of objects from structs made from the attributes
g_ = class(cell2struct(attributes(:,4), attributes(:,1), 1), 'dXgameHID');

% return the attributes, if necessary
if nargout > 1
    attributes_ = attributes;
end

% return list of batch methods
if nargout > 2
    batchMethods_ = {'reset', 'saveToFIRA', 'root', 'getJump'};
end