protected override void processData(byte[] dataChunk)
{
/* the expected data here is ..
* 1 byte = total touches
*
* 1 byte = touch id
* 2 bytes = touch x
* 2 bytes = touch y
*
* 1 byte = touch id for next touch (optional)
* ... etc
*
* */
if (dataChunk == emptyByte)
{
return;
}
uint touchScreenId = dataChunk[0]; //if a device has multiple screens, this is how we distinguish them. (this also tells us the orientation of the given screen)
uint totalTouches = dataChunk[1];
if (dataChunk.Length != (totalTouches * 5) + 2) //unexpected chunk length! Assume it is corrupted, and dump it.
{
return;
}
//assume no one is touched.
//this code assumes that touches for all touch screens are sent together during every frame (not a Unity frame, but a hardware frame).
//as opposed to touch panel A sends something frame 1, then panel B sends it's own thing the next frame. This will not work.
for (int t = 0; t < touchScreens.Length; t++)
{
if (touchScreens[t].active)
{
touchScreens[t].prepareNextFrame();
}
}
rawTouchData d = new rawTouchData();
for (int i = 2; i < dataChunk.Length; i = i + 5) //start at 1 and jump 5 each time.
{
d.id = dataChunk[i];
d.o = (touchScreenOrientation)touchScreenId;
d.iX = System.BitConverter.ToUInt16(dataChunk, i + 1);
d.iY = System.BitConverter.ToUInt16(dataChunk, i + 3);
d.x = (float)d.iX;
d.y = (float)d.iY;
touchScreens[touchScreenId]._interface(d);
}
}
//this is the method through which the touchScreenInputManager injects data into the touchScreen object
public void _interface(rawTouchData d)
{
if (!active)
{
active = true; //if we get touch events, automatically activate this touch screen. (it obviously exists on this device)
}
//sometimes the hardware sends us funky data.
//if the stats are funky, throw it out.
if (d.id == 0 || d.id >= maxTouches)
{
return;
}
if (d.x < 0 || d.x > screenResX)
{
return;
}
if (d.y < 0 || d.y > screenResY)
{
return;
}
//is this a new touch? If so, assign it to a new item in the pool, and update our iterators.
if (touchPool[touchIdMap[d.id]].state < touch.activationState.ACTIVE) //a new touch! Point it to a new element in our touchPool (we know it is new because the place where the itr is pointing to is deactivated. Hence, it must have gone through at least 1 frame where no touch info was received for it.)
{
//we can not allow either key duplicates or value duplicates in the map.
//key duplicates are already handled because an array index is by definition unique.
//however here, we have to make sure another id is not already pointing to our desired touchPoolItr.
for (int k = 0; k < maxTouches; k++)
{
if (touchIdMap[k] == touchPoolItr && k != d.id)
{
touchIdMap[k] = 0; //point it to our always defunct element. Without this, we can cause our touchCount to be incorrect.
}
}
touchIdMap[d.id] = touchPoolItr; //point the id to the current iterator
currentTouchID++;
interfaces[touchIdMap[d.id]]._id = currentTouchID; //this id, is purely for external convenience and does not affect our functions here.
touchPoolItr++;
if (touchPoolItr >= touchPoolSize)
{
touchPoolItr = 1; //we rely on element 0 always being inactive so we can use it to fix any duplicates.
}
}
interfaces[touchIdMap[d.id]].active = true;
interfaces[touchIdMap[d.id]].rawTouchScreenX = (int)d.iX;
interfaces[touchIdMap[d.id]].rawTouchScreenY = (int)d.iY;
//interfaces[touchIdMap[d.id]].orientation = d.o; //already set.
//set the normalized x/y to the touchscreen limits
mapToRange(d.x / screenResX, d.y / screenResY, topLimit, rightLimit, bottomLimit, leftLimit,
out interfaces[touchIdMap[d.id]].normalizedPos.x, out interfaces[touchIdMap[d.id]].normalizedPos.y);
interfaces[touchIdMap[d.id]].physicalPos.x = (d.x / screenResX) * touchScreenWidth;
interfaces[touchIdMap[d.id]].physicalPos.y = (d.y / screenResY) * touchScreenHeight;
}