// a first attempt at interpolation for the SampleMatrix. should be viewed as temporary.
// needs to be fleshed out with different options...
TTErr TTSampleMatrix::peeki(const TTFloat64 index, const TTColumnID channel, TTSampleValue& value)
{
// variables needed
TTColumnID p_channel = channel;
TTFloat64 indexIntegralPart = 0;
TTFloat64 indexFractionalPart = modf(index, &indexIntegralPart); // before makeInBounds to get the right value!
TTRowID indexThisInteger = TTRowID(indexIntegralPart);
TTBoolean weAreNotInBounds = makeInBounds(indexThisInteger, p_channel); // out of range values are wrapped
if (weAreNotInBounds)
{
// no reason to interpolate, just use the first or last value
get2d(indexThisInteger, p_channel, value);
return kTTErrOutOfBounds; // and report an error (is that what we want?)
} else {
TTRowID indexNextInteger = indexThisInteger + 1;
makeRowIDInBounds(indexNextInteger); //does not allow interpolation between first and last sample
// (is that what we want? if not, insert outOfBoundsWrap)
TTSampleValue valueThisInteger, valueNextInteger;
get2d(indexThisInteger, p_channel, valueThisInteger);
get2d(indexNextInteger, p_channel, valueNextInteger);
// simple linear interpolation adapted from TTDelay
value = TTInterpolateLinear(valueThisInteger, valueNextInteger, indexFractionalPart);
return kTTErrNone;
}
}
/** Perform one linear interpolation and compare the outcome to expected value.
@param x0 Sample value at prior integer index
@param x1 Sample value at next integer index
@param delta The fractional value for which we want to perform the interpolation.
delta=0 => x0 @n
delta=1 => x1
@param expectedValue The expected outcome of the interpolation
@return TRUE if the interpolat returnes the expected value, else FALSE
*/
TTFloat64 InterpolateAndTestLinear(const TTFloat64 x0, const TTFloat64 x1, const TTFloat64& aDelta, TTFloat64 anExpectedValue)
{
TTFloat64 interpolatedValue = TTInterpolateLinear(x0, x1, aDelta);
TTBoolean result = TTTestFloatEquivalence(interpolatedValue , anExpectedValue);
if (!result)
TTTestLog("BAD INTERPOLATION @ delta=%.5f ( value=%.10f expected=%.10f )", aDelta, interpolatedValue, anExpectedValue);
return result;
}
