void WaveShaperDSPKernel::process(ContextRenderLock&, const float* source, float* destination, size_t framesToProcess)
{
ASSERT(source && destination && waveShaperProcessor());
std::shared_ptr<std::vector<float>> curve = waveShaperProcessor()->curve();
if (!curve) {
// Act as "straight wire" pass-through if no curve is set.
memcpy(destination, source, sizeof(float) * framesToProcess);
return;
}
float* curveData = &(*curve)[0];
int curveLength = (*curve).size();
ASSERT(curveData);
if (!curveData || !curveLength) {
memcpy(destination, source, sizeof(float) * framesToProcess);
return;
}
// Apply waveshaping curve.
for (unsigned i = 0; i < framesToProcess; ++i) {
const float input = source[i];
// Calculate an index based on input -1 -> +1 with 0 being at the center of the curve data.
int index = (curveLength * (input + 1)) / 2;
// Clip index to the input range of the curve.
// This takes care of input outside of nominal range -1 -> +1
index = max(index, 0);
index = min(index, curveLength - 1);
destination[i] = curveData[index];
}
}
void WaveShaperDSPKernel::processCurve(const float* source, float* destination, size_t framesToProcess)
{
ASSERT(source);
ASSERT(destination);
ASSERT(waveShaperProcessor());
DOMFloat32Array* curve = waveShaperProcessor()->curve();
if (!curve) {
// Act as "straight wire" pass-through if no curve is set.
memcpy(destination, source, sizeof(float) * framesToProcess);
return;
}
float* curveData = curve->data();
int curveLength = curve->length();
ASSERT(curveData);
if (!curveData || !curveLength) {
memcpy(destination, source, sizeof(float) * framesToProcess);
return;
}
// Apply waveshaping curve.
for (unsigned i = 0; i < framesToProcess; ++i) {
const float input = source[i];
// Calculate a virtual index based on input -1 -> +1 with -1 being curve[0], +1 being
// curve[curveLength - 1], and 0 being at the center of the curve data. Then linearly
// interpolate between the two points in the curve.
double virtualIndex = 0.5 * (input + 1) * (curveLength - 1);
double output;
if (virtualIndex < 0) {
// input < -1, so use curve[0]
output = curveData[0];
} else if (virtualIndex >= curveLength - 1) {
// input >= 1, so use last curve value
output = curveData[curveLength - 1];
} else {
// The general case where -1 <= input < 1, where 0 <= virtualIndex < curveLength - 1,
// so interpolate between the nearest samples on the curve.
unsigned index1 = static_cast<unsigned>(virtualIndex);
unsigned index2 = index1 + 1;
double interpolationFactor = virtualIndex - index1;
double value1 = curveData[index1];
double value2 = curveData[index2];
output = (1.0 - interpolationFactor) * value1 + interpolationFactor * value2;
}
destination[i] = output;
}
}
void WaveShaperNode::setOversample(OverSampleType type)
{
ASSERT(isMainThread());
// Synchronize with any graph changes or changes to channel configuration.
AudioContext::AutoLocker contextLocker(context());
waveShaperProcessor()->setOversample(processorType(type));
}
void WaveShaperDSPKernel::processCurve(const float* source, float* destination, size_t framesToProcess)
{
ASSERT(source && destination && waveShaperProcessor());
Float32Array* curve = waveShaperProcessor()->curve();
if (!curve) {
// Act as "straight wire" pass-through if no curve is set.
memcpy(destination, source, sizeof(float) * framesToProcess);
return;
}
float* curveData = curve->data();
int curveLength = curve->length();
ASSERT(curveData);
if (!curveData || !curveLength) {
memcpy(destination, source, sizeof(float) * framesToProcess);
return;
}
// Apply waveshaping curve.
for (unsigned i = 0; i < framesToProcess; ++i) {
const float input = source[i];
// Calculate a virtual index based on input -1 -> +1 with 0 being at the center of the curve data.
// Then linearly interpolate between the two points in the curve.
double virtualIndex = 0.5 * (input + 1) * curveLength;
int index1 = static_cast<int>(virtualIndex);
int index2 = index1 + 1;
double interpolationFactor = virtualIndex - index1;
// Clip index to the input range of the curve.
// This takes care of input outside of nominal range -1 -> +1
index1 = max(index1, 0);
index1 = min(index1, curveLength - 1);
index2 = max(index2, 0);
index2 = min(index2, curveLength - 1);
double value1 = curveData[index1];
double value2 = curveData[index2];
double output = (1.0 - interpolationFactor) * value1 + interpolationFactor * value2;
destination[i] = output;
}
}
void WaveShaperNode::setOversample(const String& type, ExceptionCode& ec)
{
ASSERT(isMainThread());
// This is to synchronize with the changes made in
// AudioBasicProcessorNode::checkNumberOfChannelsForInput() where we can
// initialize() and uninitialize().
AudioContext::AutoLocker contextLocker(context());
if (type == "none")
waveShaperProcessor()->setOversample(WaveShaperProcessor::OverSampleNone);
else if (type == "2x")
waveShaperProcessor()->setOversample(WaveShaperProcessor::OverSample2x);
else if (type == "4x")
waveShaperProcessor()->setOversample(WaveShaperProcessor::OverSample4x);
else
ec = INVALID_STATE_ERR;
}
void WaveShaperNode::setOversample(const String& type)
{
ASSERT(isMainThread());
// This is to synchronize with the changes made in
// AudioBasicProcessorNode::checkNumberOfChannelsForInput() where we can
// initialize() and uninitialize().
AbstractAudioContext::AutoLocker contextLocker(context());
if (type == "none") {
waveShaperProcessor()->setOversample(WaveShaperProcessor::OverSampleNone);
} else if (type == "2x") {
waveShaperProcessor()->setOversample(WaveShaperProcessor::OverSample2x);
} else if (type == "4x") {
waveShaperProcessor()->setOversample(WaveShaperProcessor::OverSample4x);
} else {
ASSERT_NOT_REACHED();
}
}
void WaveShaperNode::setCurve(DOMFloat32Array* curve, ExceptionState& exceptionState)
{
ASSERT(isMainThread());
if (curve && curve->length() < 2) {
exceptionState.throwDOMException(
InvalidAccessError,
ExceptionMessages::indexExceedsMinimumBound<unsigned>(
"curve length",
curve->length(),
2));
return;
}
waveShaperProcessor()->setCurve(curve);
}
void WaveShaperDSPKernel::process(const float* source, float* destination, size_t framesToProcess)
{
switch (waveShaperProcessor()->oversample()) {
case WaveShaperProcessor::OverSampleNone:
processCurve(source, destination, framesToProcess);
break;
case WaveShaperProcessor::OverSample2x:
processCurve2x(source, destination, framesToProcess);
break;
case WaveShaperProcessor::OverSample4x:
processCurve4x(source, destination, framesToProcess);
break;
default:
ASSERT_NOT_REACHED();
}
}
Float32Array* WaveShaperNode::curve()
{
return waveShaperProcessor()->curve();
}
void WaveShaperNode::setCurve(Float32Array* curve)
{
ASSERT(isMainThread());
waveShaperProcessor()->setCurve(curve);
}
std::shared_ptr<std::vector<float>> WaveShaperNode::curve()
{
return waveShaperProcessor()->curve();
}
void WaveShaperNode::setCurve(ContextRenderLock& r, std::shared_ptr<std::vector<float>> curve)
{
waveShaperProcessor()->setCurve(r, curve);
}