public void TouchesMoved(TouchpadEventArgs arg, bool dragging)
{
if (arg.TouchReadings.Length != 2 || dragging)
{
return;
}
var lastT0 = arg.TouchReadings[0].PreviousTouchReadings;
var lastT1 = arg.TouchReadings[1].PreviousTouchReadings;
var T0 = arg.TouchReadings[0];
var T1 = arg.TouchReadings[1];
//mouse wheel 120 == 1 wheel click according to Windows API
double lastMidX = (lastT0.hwX + lastT1.hwX) / 2d, lastMidY = (lastT0.hwY + lastT1.hwY) / 2d,
currentMidX = (T0.hwX + T1.hwX) / 2d, currentMidY = (T0.hwY + T1.hwY) / 2d;
double coefficient = Global.ScrollSensitivity[deviceNumber];
// Adjust for touch distance: "standard" distance is 960 pixels, i.e. half the width. Scroll farther if fingers are farther apart, and vice versa, in linear proportion.
double touchXDistance = T1.hwX - T0.hwX, touchYDistance = T1.hwY - T0.hwY, touchDistance = Math.Sqrt(touchXDistance * touchXDistance + touchYDistance * touchYDistance);
coefficient *= touchDistance / 960.0;
// Collect rounding errors instead of losing motion.
var xMotion = coefficient * (currentMidX - lastMidX);
if (xMotion > 0.0 && horizontalRemainder > 0.0 || xMotion < 0.0 && horizontalRemainder < 0.0)
{
xMotion += horizontalRemainder;
}
var xAction = (int)xMotion;
horizontalRemainder = xMotion - xAction;
var yMotion = coefficient * (lastMidY - currentMidY);
if (yMotion > 0.0 && verticalRemainder > 0.0 || yMotion < 0.0 && verticalRemainder < 0.0)
{
yMotion += verticalRemainder;
}
var yAction = (int)yMotion;
verticalRemainder = yMotion - yAction;
if (yAction != 0 || xAction != 0)
{
InputMethods.MouseWheel(yAction, xAction);
}
}
