// add the entire signal b to this signal, at the subpixel destination offset.
//
void MLSignal::add2D(const MLSignal& b, const Vec2& destOffset)
{
MLSignal& a = *this;
Vec2 iDestOffset, fDestOffset;
destOffset.getIntAndFracParts(iDestOffset, fDestOffset);
int destX = iDestOffset[0];
int destY = iDestOffset[1];
float srcPosFX = fDestOffset[0];
float srcPosFY = fDestOffset[1];
MLRect srcRect(0, 0, b.getWidth() + 1, b.getHeight() + 1); // add (1, 1) for interpolation
MLRect destRect = srcRect.translated(iDestOffset).intersect(getBoundsRect());
for(int j=destRect.top(); j<destRect.bottom(); ++j)
{
for(int i=destRect.left(); i<destRect.right(); ++i)
{
a(i, j) += b.getInterpolatedLinear(i - destX - srcPosFX, j - destY - srcPosFY);
}
}
setConstant(false);
}
// expire or move existing touches based on new signal input.
//
void TouchTracker::updateTouches(const MLSignal& in)
{
// copy input signal to border land
int width = in.getWidth();
int height = in.getHeight();
mTemp.copy(in);
mTemplateMask.clear();
// sort active touches by Z
// copy into sorting container, referring back to unsorted touches
int activeTouches = 0;
for(int i = 0; i < mMaxTouchesPerFrame; ++i)
{
Touch& t = mTouches[i];
if (t.isActive())
{
t.unsortedIdx = i;
mTouchesToSort[activeTouches++] = t;
}
}
std::sort(mTouchesToSort.begin(), mTouchesToSort.begin() + activeTouches, compareTouchZ());
// update active touches in sorted order, referring to existing touches in place
for(int i = 0; i < activeTouches; ++i)
{
int refIdx = mTouchesToSort[i].unsortedIdx;
Touch& t = mTouches[refIdx];
Vec2 pos(t.x, t.y);
Vec2 newPos = pos;
float newX = t.x;
float newY = t.y;
float newZ = in.getInterpolatedLinear(pos);
// if not preparing to remove, update position.
if (t.releaseCtr == 0)
{
Vec2 minPos(0, 0);
Vec2 maxPos(width, height);
int ix = floor(pos.x() + 0.5f);
int iy = floor(pos.y() + 0.5f);
// move to any higher neighboring integer value
Vec2 newPeak;
newPeak = adjustPeak(mTemp, ix, iy);
Vec2 newPeakI, newPeakF;
newPeak.getIntAndFracParts(newPeakI, newPeakF);
int newPx = newPeakI.x();
int newPy = newPeakI.y();
// get exact location and new key
Vec2 correctPos = mTemp.correctPeak(newPx, newPy);
newPos = correctPos;
int newKey = getKeyIndexAtPoint(newPos);
// move the touch.
if((newKey == t.key) || !keyIsOccupied(newKey))
{
// This must be the only place a touch can move from key to key.
pos = newPos;
newX = pos.x();
newY = pos.y();
t.key = newKey;
}
}
// look for reasons to release
newZ = in.getInterpolatedLinear(newPos);
bool thresholdTest = (newZ > mOffThreshold);
float inhibit = getInhibitThreshold(pos);
bool inhibitTest = (newZ > inhibit);
t.tDist = mCalibrator.differenceFromTemplateTouchWithMask(mTemp, pos, mTemplateMask);
bool templateTest = (t.tDist < mTemplateThresh);
bool overrideTest = (newZ > mOverrideThresh);
t.age++;
// handle release
// TODO get releaseDetect: evidence that touch has been released.
// from matching release curve over ~ 50 samples.
if (!thresholdTest || (!templateTest && !overrideTest) || (!inhibitTest))
{
/* debug
if(!thresholdTest && (t.releaseCtr == 0))
{
debug() << refIdx << " REL thresholdFail: " << newZ << " at " << pos << "\n";
}
if(!inhibitTest && (t.releaseCtr == 0))
{
debug() << refIdx << " REL inhibitFail: " << newZ << " < " << inhibit << "\n";
}
if(!templateTest && (t.releaseCtr == 0))
{
debug() << refIdx << " REL templateFail: " << t.tDist << " at " << pos << "\n";
}
*/
if(t.releaseCtr == 0)
{
t.releaseSlope = t.z / (float)kTouchReleaseFrames;
}
t.releaseCtr++;
newZ = t.z - t.releaseSlope;
}
else
{
// reset off counter
t.releaseCtr = 0;
}
// filter position and assign new touch values
const float e = 2.718281828;
float xyCutoff = (newZ - mOnThreshold) / (mMaxForce*0.25);
xyCutoff = clamp(xyCutoff, 0.f, 1.f);
xyCutoff *= xyCutoff;
xyCutoff *= xyCutoff;
xyCutoff = xyCutoff*100.;
xyCutoff = clamp(xyCutoff, 1.f, 100.f);
float x = powf(e, -kMLTwoPi * xyCutoff / (float)mSampleRate);
float a0 = 1.f - x;
float b1 = -x;
t.dz = newZ - t.z;
// these can't be filtered too much or updateTouches will not work
// for fast movements. Revisit when we rewrite the touch tracker.
t.x = a0*newX - b1*t.x;
t.y = a0*newY - b1*t.y;
t.z = newZ;
// filter z based on user lowpass setting and touch age
float lp = mLopass;
lp -= t.age*(mLopass*0.75f/kAttackFrames);
lp = clamp(lp, mLopass, mLopass*0.25f); // WTF???
float xz = powf(e, -kMLTwoPi * lp / (float)mSampleRate);
float a0z = 1.f - xz;
float b1z = -xz;
t.zf = a0z*(newZ - mOnThreshold) - b1z*t.zf;
// remove touch if filtered z is below threshold
if(t.zf < 0.)
{
// debug() << refIdx << " OFF with z:" << t.z << " td:" << t.tDist << "\n";
removeTouchAtIndex(refIdx);
}
// subtract updated touch from the input sum.
// mTemplateScaled is scratch space.
mTemplateScaled.clear();
mTemplateScaled.add2D(mCalibrator.getTemplate(pos), 0, 0);
mTemplateScaled.scale(-t.z*mCalibrator.getZAdjust(pos));
mTemp.add2D(mTemplateScaled, Vec2(pos - Vec2(kTemplateRadius, kTemplateRadius)));
mTemp.sigMax(0.0);
// add touch neighborhood to template mask. This allows crowded touches
// to pass the template test by ignoring areas shared with other touches.
Vec2 maskPos(t.x, t.y);
const MLSignal& tmplate = mCalibrator.getTemplate(maskPos);
mTemplateMask.add2D(tmplate, maskPos - Vec2(kTemplateRadius, kTemplateRadius));
}
}
float TouchTracker::Calibrator::differenceFromTemplateTouchWithMask(const MLSignal& in, Vec2 pos, const MLSignal& mask)
{
static float maskThresh = 0.001f;
static MLSignal a2(kTemplateSize, kTemplateSize);
static MLSignal b(kTemplateSize, kTemplateSize);
static MLSignal b2(kTemplateSize, kTemplateSize);
float r = 0.f;
int height = in.getHeight();
int width = in.getWidth();
MLRect boundsRect(0, 0, width, height);
// use linear interpolated z value from input
float linearZ = in.getInterpolatedLinear(pos)*getZAdjust(pos);
linearZ = clamp(linearZ, 0.00001f, 1.f);
float z1 = 1./linearZ;
const MLSignal& a = getTemplate(pos);
// get normalized input values surrounding touch
int tr = kTemplateRadius;
b.clear();
for(int j=0; j < kTemplateSize; ++j)
{
for(int i=0; i < kTemplateSize; ++i)
{
Vec2 vInPos = pos + Vec2((float)i - tr,(float)j - tr);
if (boundsRect.contains(vInPos) && (mask.getInterpolatedLinear(vInPos) < maskThresh))
{
float inVal = in.getInterpolatedLinear(vInPos);
inVal *= z1;
b(i, j) = inVal;
}
}
}
int tests = 0;
float sum = 0.;
// add differences in z from template
a2.copy(a);
b2.copy(b);
a2.partialDiffX();
b2.partialDiffX();
for(int j=0; j < kTemplateSize; ++j)
{
for(int i=0; i < kTemplateSize; ++i)
{
if(b(i, j) > 0.)
{
float d = a2(i, j) - b2(i, j);
sum += d*d;
tests++;
}
}
}
// get RMS difference
if(tests > 0)
{
r = sqrtf(sum / tests);
}
return r;
}