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/*
* DISTRHO Plugin Framework (DPF)
* Copyright (C) 2012-2015 Filipe Coelho <falktx@falktx.com>
*
* Permission to use, copy, modify, and/or distribute this software for any purpose with
* or without fee is hereby granted, provided that the above copyright notice and this
* permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
* TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "DistrhoPlugin.hpp"
START_NAMESPACE_DISTRHO
// -----------------------------------------------------------------------------------------------------------
/**
Plugin that demonstrates the latency API in DPF.
*/
class LatencyExamplePlugin : public Plugin
{
public:
LatencyExamplePlugin()
: Plugin(1, 0, 0), // 1 parameter
fLatency(1.0f),
fLatencyInFrames(0),
fBuffer(nullptr),
fBufferPos(0)
{
// allocates buffer
sampleRateChanged(getSampleRate());
}
~LatencyExamplePlugin() override
{
delete[] fBuffer;
}
protected:
/* --------------------------------------------------------------------------------------------------------
* Information */
/**
Get the plugin label.
This label is a short restricted name consisting of only _, a-z, A-Z and 0-9 characters.
*/
const char* getLabel() const override
{
return "Latency";
}
/**
Get an extensive comment/description about the plugin.
*/
const char* getDescription() const override
{
return "Plugin that demonstrates the latency API in DPF.";
}
/**
Get the plugin author/maker.
*/
const char* getMaker() const override
{
return "DISTRHO";
}
/**
Get the plugin homepage.
*/
const char* getHomePage() const override
{
return "https://github.com/DISTRHO/DPF";
}
/**
Get the plugin license name (a single line of text).
For commercial plugins this should return some short copyright information.
*/
const char* getLicense() const override
{
return "ISC";
}
/**
Get the plugin version, in hexadecimal.
*/
uint32_t getVersion() const override
{
return d_version(1, 0, 0);
}
/**
Get the plugin unique Id.
This value is used by LADSPA, DSSI and VST plugin formats.
*/
int64_t getUniqueId() const override
{
return d_cconst('d', 'L', 'a', 't');
}
/* --------------------------------------------------------------------------------------------------------
* Init */
/**
Initialize the parameter @a index.
This function will be called once, shortly after the plugin is created.
*/
void initParameter(uint32_t index, Parameter& parameter) override
{
if (index != 0)
return;
parameter.hints = kParameterIsAutomable;
parameter.name = "Latency";
parameter.symbol = "latency";
parameter.unit = "s";
parameter.ranges.def = 1.0f;
parameter.ranges.min = 0.0f;
parameter.ranges.max = 5.0f;
}
/* --------------------------------------------------------------------------------------------------------
* Internal data */
/**
Get the current value of a parameter.
The host may call this function from any context, including realtime processing.
*/
float getParameterValue(uint32_t index) const override
{
if (index != 0)
return 0.0f;
return fLatency;
}
/**
Change a parameter value.
The host may call this function from any context, including realtime processing.
When a parameter is marked as automable, you must ensure no non-realtime operations are performed.
@note This function will only be called for parameter inputs.
*/
void setParameterValue(uint32_t index, float value) override
{
if (index != 0)
return;
fLatency = value;
fLatencyInFrames = value*getSampleRate();
setLatency(fLatencyInFrames);
}
/* --------------------------------------------------------------------------------------------------------
* Audio/MIDI Processing */
/**
Run/process function for plugins without MIDI input.
@note Some parameters might be null if there are no audio inputs or outputs.
*/
void run(const float** inputs, float** outputs, uint32_t frames) override
{
const float* const in = inputs[0];
/* */ float* const out = outputs[0];
if (fLatencyInFrames == 0)
{
if (out != in)
std::memcpy(out, in, sizeof(float)*frames);
return;
}
// Put the new audio in the buffer.
std::memcpy(fBuffer+fBufferPos, in, sizeof(float)*frames);
fBufferPos += frames;
// buffer is not filled enough yet
if (fBufferPos < fLatencyInFrames+frames)
{
// silence output
std::memset(out, 0, sizeof(float)*frames);
}
// buffer is ready to copy
else
{
// copy latency buffer to output
const uint32_t readPos = fBufferPos-fLatencyInFrames-frames;
std::memcpy(out, fBuffer+readPos, sizeof(float)*frames);
// move latency buffer back by some frames
std::memmove(fBuffer, fBuffer+frames, sizeof(float)*fBufferPos);
fBufferPos -= frames;
}
}
/* --------------------------------------------------------------------------------------------------------
* Callbacks (optional) */
/**
Optional callback to inform the plugin about a sample rate change.
This function will only be called when the plugin is deactivated.
*/
void sampleRateChanged(double newSampleRate) override
{
if (fBuffer != nullptr)
delete[] fBuffer;
const uint32_t maxFrames = newSampleRate*6; // 6 seconds
fBuffer = new float[maxFrames];
std::memset(fBuffer, 0, sizeof(float)*maxFrames);
fLatencyInFrames = fLatency*newSampleRate;
fBufferPos = 0;
}
// -------------------------------------------------------------------------------------------------------
private:
// Parameters
float fLatency;
uint32_t fLatencyInFrames;
// Buffer for previous audio, size depends on sample rate
float* fBuffer;
uint32_t fBufferPos;
/**
Set our plugin class as non-copyable and add a leak detector just in case.
*/
DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(LatencyExamplePlugin)
};
/* ------------------------------------------------------------------------------------------------------------
* Plugin entry point, called by DPF to create a new plugin instance. */
Plugin* createPlugin()
{
return new LatencyExamplePlugin();
}
// -----------------------------------------------------------------------------------------------------------
END_NAMESPACE_DISTRHO
|
