diff options
Diffstat (limited to 'examples/Latency/LatencyExamplePlugin.cpp')
| -rw-r--r-- | examples/Latency/LatencyExamplePlugin.cpp | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/examples/Latency/LatencyExamplePlugin.cpp b/examples/Latency/LatencyExamplePlugin.cpp new file mode 100644 index 00000000..5dce73f5 --- /dev/null +++ b/examples/Latency/LatencyExamplePlugin.cpp @@ -0,0 +1,251 @@ +/*
+ * 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/plugin-examples";
+ }
+
+ /**
+ 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
|