private void HandleHidReport(byte[] hidReport, byte[] preparsedData)
{
// Check each of the possible contacts
for (int i = 0; i < Constants.MaxContacts; i++)
{
// Are there any active usages on the contact's link collection?
ushort[] contactUsages =
Hid.HidP_GetUsages(HidPReportType.HidP_Input, Constants.PressureUsage.UsagePage, (ushort)(i + 1), preparsedData, hidReport);
// If not, it isn't active.
bool contactActive = contactUsages.Any();
// Next, if we think it might be active, we check the pressure value.
uint pressure = 0;
if (contactActive)
{
pressure =
Hid.HidP_GetUsageValue(HidPReportType.HidP_Input, Constants.PressureUsage, (ushort)(i + 1), preparsedData, hidReport);
// If it is below the minimum threshold, we change our minds.
if (pressure < MinimumDetectionPressure)
{
contactActive = false;
}
}
// If the contact isn't active, we don't need to check the x/y values.
if (!contactActive)
{
// If it was previously active, we fire the OnContactEnd event.
if (activeContacts[i])
{
OnContactEnd(new TouchpadEventArgs
{
ContactIndex = i
});
// ..and set it back to inactive
activeContacts[i] = false;
}
// Continue on to the next possible contact
continue;
}
// Okay, we've got a *for real* active contact. Let's check the x/y values.
uint x = Hid.HidP_GetUsageValue(HidPReportType.HidP_Input, Constants.PositionXUsage, (ushort)(i + 1), preparsedData, hidReport);
uint y = Hid.HidP_GetUsageValue(HidPReportType.HidP_Input, Constants.PositionYUsage, (ushort)(i + 1), preparsedData, hidReport);
// We're going to either be calling OnContactStart or OnContactUpdate,
// but with the same EventArgs either way. So let's go ahead and create it.
TouchpadEventArgs e = new TouchpadEventArgs
{
ContactIndex = i,
Pressure = pressure,
X = x,
Y = y
};
// Fire the appropriate event.
if (activeContacts[i])
{
OnContactUpdate(e);
}
else
{
OnContactStart(e);
// This contact has started, and it is now active.
activeContacts[i] = true;
}
}
}
protected virtual void OnContactEnd(TouchpadEventArgs e)
{
TouchpadEventHandler handler = ContactEnd;
handler?.Invoke(this, e);
}
