Add gain example plugin (#119)

* Add gain example plugin

* Add missing overridden methods

5 files changed, 284 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index b8b23a22..70b8cc72 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@ dgl:
 	$(MAKE) -C dgl
 
 examples: dgl
+	$(MAKE) all -C examples/Gain
 	$(MAKE) all -C examples/Info
 	$(MAKE) all -C examples/Latency
 	$(MAKE) all -C examples/Meters
diff --git a/examples/Gain/DistrhoPluginInfo.h b/examples/Gain/DistrhoPluginInfo.h
new file mode 100644
index 00000000..76d45f85
--- /dev/null
+++ b/examples/Gain/DistrhoPluginInfo.h
@@ -0,0 +1,30 @@
+/*
+ * 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.
+ */
+
+#ifndef DISTRHO_PLUGIN_INFO_H_INCLUDED
+#define DISTRHO_PLUGIN_INFO_H_INCLUDED
+
+#define DISTRHO_PLUGIN_BRAND "DISTRHO"
+#define DISTRHO_PLUGIN_NAME  "Gain"
+#define DISTRHO_PLUGIN_URI   "http://distrho.sf.net/examples/Gain"
+
+#define DISTRHO_PLUGIN_HAS_UI       0
+#define DISTRHO_PLUGIN_IS_RT_SAFE   1
+#define DISTRHO_PLUGIN_NUM_INPUTS   1
+#define DISTRHO_PLUGIN_NUM_OUTPUTS  1
+#define DISTRHO_PLUGIN_WANT_LATENCY 0
+
+#endif // DISTRHO_PLUGIN_INFO_H_INCLUDED
diff --git a/examples/Gain/GainExamplePlugin.cpp b/examples/Gain/GainExamplePlugin.cpp
new file mode 100644
index 00000000..bfd06ed6
--- /dev/null
+++ b/examples/Gain/GainExamplePlugin.cpp
@@ -0,0 +1,210 @@
+/*
+ * 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 basic API in DPF.
+ */
+class GainExamplePlugin : public Plugin
+{
+public:
+    GainExamplePlugin()
+        : Plugin(1, 0, 0), // 1 parameter
+          fGain(1.0)
+    {
+    }
+
+    ~GainExamplePlugin() override
+    {
+    }
+
+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 "Gain";
+    }
+
+   /**
+      Get an extensive comment/description about the plugin.
+    */
+    const char* getDescription() const override
+    {
+        return "Plugin that demonstrates the basic 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', 'G', 'a', 'i');
+    }
+
+   /* --------------------------------------------------------------------------------------------------------
+    * 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   = "Gain";
+        parameter.symbol = "gain";
+        parameter.unit   = "dB";
+        parameter.ranges.def = 1.0f;
+        parameter.ranges.min = 0.0f;
+        parameter.ranges.max = 1.0f;
+    }
+
+    void initProgramName(uint32_t index, String& programName) override
+    {
+        if (index != 0) {
+            programName = "";
+            return;
+	}
+
+        programName = "Default";
+    }
+
+    void loadProgram(uint32_t index) override
+    {
+        if (index != 0)
+            return;
+
+        fGain = 1.0;
+    }
+
+   /* --------------------------------------------------------------------------------------------------------
+    * 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 fGain;
+    }
+
+   /**
+      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;
+
+        fGain = value;
+    }
+
+   /* --------------------------------------------------------------------------------------------------------
+    * 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];
+        uint32_t i;
+
+        for (i = 0; i < frames; i++) {
+            out[i] = in[i] * fGain;
+        }
+    }
+
+    // -------------------------------------------------------------------------------------------------------
+
+private:
+    // Parameters
+    float fGain;
+
+   /**
+      Set our plugin class as non-copyable and add a leak detector just in case.
+    */
+    DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(GainExamplePlugin)
+};
+
+/* ------------------------------------------------------------------------------------------------------------
+ * Plugin entry point, called by DPF to create a new plugin instance. */
+
+Plugin* createPlugin()
+{
+    return new GainExamplePlugin();
+}
+
+// -----------------------------------------------------------------------------------------------------------
+
+END_NAMESPACE_DISTRHO
diff --git a/examples/Gain/Makefile b/examples/Gain/Makefile
new file mode 100644
index 00000000..4a93197a
--- /dev/null
+++ b/examples/Gain/Makefile
@@ -0,0 +1,36 @@
+#!/usr/bin/make -f
+# Makefile for DISTRHO Plugins #
+# ---------------------------- #
+# Created by falkTX
+#
+
+# --------------------------------------------------------------
+# Project name, used for binaries
+
+NAME = d_gain
+
+# --------------------------------------------------------------
+# Files to build
+
+FILES_DSP = \
+	GainExamplePlugin.cpp
+
+# --------------------------------------------------------------
+# Do some magic
+
+include ../../Makefile.plugins.mk
+
+# --------------------------------------------------------------
+# Enable all possible plugin types
+
+ifeq ($(LINUX),true)
+TARGETS += ladspa
+TARGETS += dssi
+endif
+
+TARGETS += lv2_dsp
+TARGETS += vst
+
+all: $(TARGETS)
+
+# --------------------------------------------------------------
diff --git a/examples/Gain/README.md b/examples/Gain/README.md
new file mode 100644
index 00000000..3be0679b
--- /dev/null
+++ b/examples/Gain/README.md
@@ -0,0 +1,7 @@
+# Gain example
+
+This example will show how to create a simple plugin in DPF with one parameter.<br/>
+
+The plugin will alter the gain by multiplying the input samples by a constant factor 0-1.<br/>
+
+The plugin has no UI because there's no need for one in this case.<br/>