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Store XML parameter values with names and as internal (not normalised…
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…) values, also provide migration from previous format
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@jd-13
jd-13 committed Mar 3, 2021
1 parent cad51c9 commit 65ed418
Showing 1 changed file with 80 additions and 47 deletions.
127 changes: 80 additions & 47 deletions WECore/CoreJUCEPlugin/CoreAudioProcessor.h
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Original file line number Diff line number Diff line change
Expand Up @@ -106,13 +106,28 @@ namespace WECore::JUCEPlugin {
std::function<void(bool)> setter);
/** @} */

/**
* Override this and return a vector of parameter names corresponding to the order that
* parameters were stored in using the legacy schema.
*/
virtual std::vector<juce::String> _provideParamNamesForMigration() = 0;

/**
* Override this to migrate saved parameter values from normalised to internal.
*/
virtual void _migrateParamValues(std::vector<float>& paramValues) = 0;

private:

// Increment this after changing how parameter states are stored
static constexpr int PARAMS_SCHEMA_VERSION {1};

/**
* Stores a setter and getter for a parameter. Used when persisting parameter values to XML
* and restoring values from XML.
*/
struct ParameterInterface {
juce::String name;
std::function<float()> getter;
std::function<void(float)> setter;
};
Expand Down Expand Up @@ -145,48 +160,47 @@ namespace WECore::JUCEPlugin {

inline std::vector<float> _stringToFloatVector(const juce::String sFloatCSV) const;

inline std::unique_ptr<juce::XmlElement> _migrateParameters(
std::unique_ptr<juce::XmlElement> rootElement);

JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(CoreAudioProcessor)
};

void CoreAudioProcessor::getStateInformation(juce::MemoryBlock& destData)
{
// Compile the list of parameter values
std::vector<float> paramValues;
// Build the XML
juce::XmlElement rootElement("Root");

// Set the XML params version
rootElement.setAttribute("SchemaVersion", PARAMS_SCHEMA_VERSION);

// Store the parameters
juce::XmlElement* paramsElement = rootElement.createNewChildElement("Params");
for (const ParameterInterface& param : _paramsList) {
paramValues.push_back(param.getter());
paramsElement->setAttribute(param.name, param.getter());
}

// Build the XML
juce::XmlElement root("Root");
juce::XmlElement *el = root.createNewChildElement("AllUserParam");

el->addTextElement(juce::String(_floatVectorToString(paramValues)));
copyXmlToBinary(root, destData);
copyXmlToBinary(rootElement, destData);
}

void CoreAudioProcessor::setStateInformation(const void* data, int sizeInBytes)
{
std::unique_ptr<juce::XmlElement> pRoot(getXmlFromBinary(data, sizeInBytes));
std::unique_ptr<juce::XmlElement> rootElement(getXmlFromBinary(data, sizeInBytes));

// Parse the XML
if (pRoot != NULL) {
forEachXmlChildElement((*pRoot), pChild) {
if (pChild->hasTagName("AllUserParam")) {
if (rootElement != nullptr) {

// Read the values into a float array
juce::String sFloatCSV = pChild->getAllSubText();
const std::vector<float> readParamValues = _stringToFloatVector(sFloatCSV);

// Pass each value read from XML to a setter, being careful not to go out of
// range on either of the vectors
//
// For this to work it relies the order not changing between plugin versions,
// otherwise parameter values written by an old version will be assigned to the
// wrong parameters in a new version (new parameters are ok though)
for (int idx {0}; idx < _paramsList.size(); idx++) {
if (idx < readParamValues.size()) {
_paramsList[idx].setter(readParamValues[idx]);
}
// If state was saved using an old plugin we need to migrate the XML data
if (rootElement->getIntAttribute("SchemaVersion", 0) < PARAMS_SCHEMA_VERSION) {
rootElement = _migrateParameters(std::move(rootElement));
}

// Iterate through our list of parameters, restoring them from the XML attributes
juce::XmlElement* paramsElement = rootElement->getChildByName("Params");
if (paramsElement != nullptr) {
for (const ParameterInterface& param : _paramsList) {
if (paramsElement->hasAttribute(param.name)) {
param.setter(paramsElement->getDoubleAttribute(param.name));
}
}
}
Expand All @@ -201,8 +215,9 @@ namespace WECore::JUCEPlugin {
std::function<void(float)> setter) {
param = new juce::AudioParameterFloat(name, name, {0.0f, 1.0f, precision}, range->InternalToNormalised(defaultValue));

ParameterInterface interface = {[&param]() { return param->get(); },
setter};
ParameterInterface interface = {name,
[&param, range]() { return range->NormalisedToInternal(param->get()); },
[setter, range](float val) { setter(range->InternalToNormalised(val)); }};
_paramsList.push_back(interface);

param->addListener(&_parameterBroadcaster);
Expand All @@ -216,7 +231,8 @@ namespace WECore::JUCEPlugin {
std::function<void(int)> setter) {
param = new juce::AudioParameterInt(name, name, range->minValue, range->maxValue, defaultValue);

ParameterInterface interface = {[&param]() { return param->get(); },
ParameterInterface interface = {name,
[&param]() { return param->get(); },
[setter](float val) { setter(static_cast<int>(val)); }};
_paramsList.push_back(interface);

Expand All @@ -230,30 +246,15 @@ namespace WECore::JUCEPlugin {
std::function<void(bool)> setter) {
param = new juce::AudioParameterBool(name, name, defaultValue);

ParameterInterface interface = {[&param]() { return param->get(); },
ParameterInterface interface = {name,
[&param]() { return param->get(); },
[setter](float val) { setter(static_cast<bool>(val)); }};
_paramsList.push_back(interface);

param->addListener(&_parameterBroadcaster);
addParameter(param);
}

juce::String CoreAudioProcessor::_floatVectorToString(const std::vector<float>& fData) const {
juce::String result {""};

if (fData.size() < 1) {
return result;
}

for (int iii {0}; iii < (fData.size() - 1); iii++) {
result << juce::String(fData[iii])<<",";
}

result << juce::String(fData[fData.size() - 1]);

return result;
}

std::vector<float> CoreAudioProcessor::_stringToFloatVector(const juce::String sFloatCSV) const {
juce::StringArray tokenizer;
tokenizer.addTokens(sFloatCSV, ",","");
Expand All @@ -266,4 +267,36 @@ namespace WECore::JUCEPlugin {

return values;
}

std::unique_ptr<juce::XmlElement> CoreAudioProcessor::_migrateParameters(std::unique_ptr<juce::XmlElement> rootElement) {
const int schemaVersion {rootElement->getIntAttribute("SchemaVersion", 0)};

std::unique_ptr<juce::XmlElement> retVal = std::make_unique<juce::XmlElement>("Root");

if (schemaVersion == 0) {
// This is an original parameter schema - parameters are normalised values in a single string

forEachXmlChildElement((*rootElement), childElement) {
if (childElement->hasTagName("AllUserParam")) {

// Read the values into a float array
juce::String sFloatCSV = childElement->getAllSubText();
std::vector<float> readParamValues = _stringToFloatVector(sFloatCSV);
_migrateParamValues(readParamValues);

std::vector<juce::String> paramNames = _provideParamNamesForMigration();

juce::XmlElement* paramsElement = retVal->createNewChildElement("Params");

for (int idx {0}; idx < paramNames.size(); idx++) {
if (idx < readParamValues.size()) {
paramsElement->setAttribute(paramNames[idx], readParamValues[idx]);
}
}
}
}
}

return retVal;
}
}

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