MICROSOFT_PRESS_EBOOK_PROGRAMMING_WINDOWS_8_APPS_WITH_HTML_CSS_AND_JAVASCRIPT_PDF

auto stateResult = XInputGetState(m_index, &m_xinputState);
if (stateResult == ERROR_SUCCESS)
{
m_isControllerConnected = true;
controllerState.connected = true;
controllerState.controllerId = m_index;
controllerState.packetNumber = m_xinputState.dwPacketNumber;
controllerState.LeftTrigger = m_xinputState.Gamepad.bLeftTrigger;
controllerState.RightTrigger = m_xinputState.Gamepad.bRightTrigger;
// And so on [copying all the other properties omitted.]
}
else
{
m_isControllerConnected = false;
}
}
return controllerState;
The constructor for a Controller object is also very simple:
Controller::Controller(uint32 index)
{
m_index = index;
m_lastEnumTime = ::GetTickCount64() - EnumerateTimeout;
}
In a JavaScript app—once the reference to the component has been added—the GameController
namespace contains the component’s public API, and we can utilize it as if it were built right into
Windows. In the case of the sample, it first instantiates a Controller object (with index of zero) and then
kicks off animation frames (program.js):
app.onactivated = function (eventObj) {
if (eventObj.detail.kind ===
Windows.ApplicationModel.Activation.ActivationKind.launch) {
// [Other setup omitted]
// Instantiate the Controller object from the WinRT component
controller = new GameController.Controller(0);
};
};
// Start rendering loop
requestAnimationFrame(renderLoop);
The renderLoop function then just calls the component’s getState method and applies the results to a canvas
drawing before repeating the loop (also in program.js, though much code omitted):
694