Added a simple spectrogram example app.

examples/SimpleFFTExample/Builds/MacOSX/Info.plist

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist>
+  <dict>
+    <key>CFBundleExecutable</key>
+    <string>${EXECUTABLE_NAME}</string>
+    <key>CFBundleIconFile</key>
+    <string></string>
+    <key>CFBundleIdentifier</key>
+    <string>com.yourcompany.SimpleFFTExample</string>
+    <key>CFBundleName</key>
+    <string>SimpleFFTExample</string>
+    <key>CFBundlePackageType</key>
+    <string>APPL</string>
+    <key>CFBundleSignature</key>
+    <string>????</string>
+    <key>CFBundleShortVersionString</key>
+    <string>1.0.0</string>
+    <key>CFBundleVersion</key>
+    <string>1.0.0</string>
+    <key>NSHumanReadableCopyright</key>
+    <string></string>
+    <key>NSHighResolutionCapable</key>
+    <true/>
+  </dict>
+</plist>

examples/SimpleFFTExample/Builds/VisualStudio2013/SimpleFFTExample.sln

@@ -0,0 +1,19 @@
+Microsoft Visual Studio Solution File, Format Version 11.00
+# Visual Studio 2013
+Project("{E2F0E2D2-88FF-EF53-E779-C571B75BEB02}") = "SimpleFFTExample", "SimpleFFTExample.vcxproj", "{D3EA4D64-39DA-D13A-AC10-C306C86BA9F5}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Win32 = Debug|Win32
+		Release|Win32 = Release|Win32
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{D3EA4D64-39DA-D13A-AC10-C306C86BA9F5}.Debug|Win32.ActiveCfg = Debug|Win32
+		{D3EA4D64-39DA-D13A-AC10-C306C86BA9F5}.Debug|Win32.Build.0 = Debug|Win32
+		{D3EA4D64-39DA-D13A-AC10-C306C86BA9F5}.Release|Win32.ActiveCfg = Release|Win32
+		{D3EA4D64-39DA-D13A-AC10-C306C86BA9F5}.Release|Win32.Build.0 = Release|Win32
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

examples/SimpleFFTExample/Builds/VisualStudio2013/resources.rc

@@ -0,0 +1,29 @@
+#ifdef JUCE_USER_DEFINED_RC_FILE
+ #include JUCE_USER_DEFINED_RC_FILE
+#else
+
+#undef  WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+VS_VERSION_INFO VERSIONINFO
+FILEVERSION  1,0,0,0
+BEGIN
+  BLOCK "StringFileInfo"
+  BEGIN
+    BLOCK "040904E4"
+    BEGIN
+      VALUE "FileDescription",  "SimpleFFTExample\0"
+      VALUE "FileVersion",  "1.0.0\0"
+      VALUE "ProductName",  "SimpleFFTExample\0"
+      VALUE "ProductVersion",  "1.0.0\0"
+    END
+  END
+
+  BLOCK "VarFileInfo"
+  BEGIN
+    VALUE "Translation", 0x409, 65001
+  END
+END
+
+#endif

examples/SimpleFFTExample/JuceLibraryCode/AppConfig.h

@@ -0,0 +1,179 @@
+/*
+
+    IMPORTANT! This file is auto-generated each time you save your
+    project - if you alter its contents, your changes may be overwritten!
+
+    There's a section below where you can add your own custom code safely, and the
+    Introjucer will preserve the contents of that block, but the best way to change
+    any of these definitions is by using the Introjucer's project settings.
+
+    Any commented-out settings will assume their default values.
+
+*/
+
+#ifndef __JUCE_APPCONFIG_CGCXPD__
+#define __JUCE_APPCONFIG_CGCXPD__
+
+//==============================================================================
+// [BEGIN_USER_CODE_SECTION]
+
+// (You can add your own code in this section, and the Introjucer will not overwrite it)
+
+// [END_USER_CODE_SECTION]
+
+//==============================================================================
+#define JUCE_MODULE_AVAILABLE_juce_audio_basics          1
+#define JUCE_MODULE_AVAILABLE_juce_audio_devices         1
+#define JUCE_MODULE_AVAILABLE_juce_audio_formats         1
+#define JUCE_MODULE_AVAILABLE_juce_audio_processors      1
+#define JUCE_MODULE_AVAILABLE_juce_audio_utils           1
+#define JUCE_MODULE_AVAILABLE_juce_core                  1
+#define JUCE_MODULE_AVAILABLE_juce_data_structures       1
+#define JUCE_MODULE_AVAILABLE_juce_events                1
+#define JUCE_MODULE_AVAILABLE_juce_graphics              1
+#define JUCE_MODULE_AVAILABLE_juce_gui_basics            1
+#define JUCE_MODULE_AVAILABLE_juce_gui_extra             1
+
+//==============================================================================
+// juce_audio_devices flags:
+
+#ifndef    JUCE_ASIO
+ //#define JUCE_ASIO
+#endif
+
+#ifndef    JUCE_WASAPI
+ //#define JUCE_WASAPI
+#endif
+
+#ifndef    JUCE_WASAPI_EXCLUSIVE
+ //#define JUCE_WASAPI_EXCLUSIVE
+#endif
+
+#ifndef    JUCE_DIRECTSOUND
+ //#define JUCE_DIRECTSOUND
+#endif
+
+#ifndef    JUCE_ALSA
+ //#define JUCE_ALSA
+#endif
+
+#ifndef    JUCE_JACK
+ //#define JUCE_JACK
+#endif
+
+#ifndef    JUCE_USE_ANDROID_OPENSLES
+ //#define JUCE_USE_ANDROID_OPENSLES
+#endif
+
+#ifndef    JUCE_USE_CDREADER
+ //#define JUCE_USE_CDREADER
+#endif
+
+#ifndef    JUCE_USE_CDBURNER
+ //#define JUCE_USE_CDBURNER
+#endif
+
+//==============================================================================
+// juce_audio_formats flags:
+
+#ifndef    JUCE_USE_FLAC
+ //#define JUCE_USE_FLAC
+#endif
+
+#ifndef    JUCE_USE_OGGVORBIS
+ //#define JUCE_USE_OGGVORBIS
+#endif
+
+#ifndef    JUCE_USE_MP3AUDIOFORMAT
+ //#define JUCE_USE_MP3AUDIOFORMAT
+#endif
+
+#ifndef    JUCE_USE_LAME_AUDIO_FORMAT
+ //#define JUCE_USE_LAME_AUDIO_FORMAT
+#endif
+
+#ifndef    JUCE_USE_WINDOWS_MEDIA_FORMAT
+ //#define JUCE_USE_WINDOWS_MEDIA_FORMAT
+#endif
+
+//==============================================================================
+// juce_audio_processors flags:
+
+#ifndef    JUCE_PLUGINHOST_VST
+ //#define JUCE_PLUGINHOST_VST
+#endif
+
+#ifndef    JUCE_PLUGINHOST_VST3
+ //#define JUCE_PLUGINHOST_VST3
+#endif
+
+#ifndef    JUCE_PLUGINHOST_AU
+ //#define JUCE_PLUGINHOST_AU
+#endif
+
+//==============================================================================
+// juce_core flags:
+
+#ifndef    JUCE_FORCE_DEBUG
+ //#define JUCE_FORCE_DEBUG
+#endif
+
+#ifndef    JUCE_LOG_ASSERTIONS
+ //#define JUCE_LOG_ASSERTIONS
+#endif
+
+#ifndef    JUCE_CHECK_MEMORY_LEAKS
+ //#define JUCE_CHECK_MEMORY_LEAKS
+#endif
+
+#ifndef    JUCE_DONT_AUTOLINK_TO_WIN32_LIBRARIES
+ //#define JUCE_DONT_AUTOLINK_TO_WIN32_LIBRARIES
+#endif
+
+#ifndef    JUCE_INCLUDE_ZLIB_CODE
+ //#define JUCE_INCLUDE_ZLIB_CODE
+#endif
+
+//==============================================================================
+// juce_graphics flags:
+
+#ifndef    JUCE_USE_COREIMAGE_LOADER
+ //#define JUCE_USE_COREIMAGE_LOADER
+#endif
+
+#ifndef    JUCE_USE_DIRECTWRITE
+ //#define JUCE_USE_DIRECTWRITE
+#endif
+
+//==============================================================================
+// juce_gui_basics flags:
+
+#ifndef    JUCE_ENABLE_REPAINT_DEBUGGING
+ //#define JUCE_ENABLE_REPAINT_DEBUGGING
+#endif
+
+#ifndef    JUCE_USE_XSHM
+ //#define JUCE_USE_XSHM
+#endif
+
+#ifndef    JUCE_USE_XRENDER
+ //#define JUCE_USE_XRENDER
+#endif
+
+#ifndef    JUCE_USE_XCURSOR
+ //#define JUCE_USE_XCURSOR
+#endif
+
+//==============================================================================
+// juce_gui_extra flags:
+
+#ifndef    JUCE_WEB_BROWSER
+ //#define JUCE_WEB_BROWSER
+#endif
+
+#ifndef    JUCE_ENABLE_LIVE_CONSTANT_EDITOR
+ //#define JUCE_ENABLE_LIVE_CONSTANT_EDITOR
+#endif
+
+
+#endif  // __JUCE_APPCONFIG_CGCXPD__

examples/SimpleFFTExample/JuceLibraryCode/JuceHeader.h

@@ -0,0 +1,44 @@
+/*
+
+    IMPORTANT! This file is auto-generated each time you save your
+    project - if you alter its contents, your changes may be overwritten!
+
+    This is the header file that your files should include in order to get all the
+    JUCE library headers. You should avoid including the JUCE headers directly in
+    your own source files, because that wouldn't pick up the correct configuration
+    options for your app.
+
+*/
+
+#ifndef __APPHEADERFILE_CGCXPD__
+#define __APPHEADERFILE_CGCXPD__
+
+#include "AppConfig.h"
+#include "modules/juce_audio_basics/juce_audio_basics.h"
+#include "modules/juce_audio_devices/juce_audio_devices.h"
+#include "modules/juce_audio_formats/juce_audio_formats.h"
+#include "modules/juce_audio_processors/juce_audio_processors.h"
+#include "modules/juce_audio_utils/juce_audio_utils.h"
+#include "modules/juce_core/juce_core.h"
+#include "modules/juce_data_structures/juce_data_structures.h"
+#include "modules/juce_events/juce_events.h"
+#include "modules/juce_graphics/juce_graphics.h"
+#include "modules/juce_gui_basics/juce_gui_basics.h"
+#include "modules/juce_gui_extra/juce_gui_extra.h"
+
+#if ! DONT_SET_USING_JUCE_NAMESPACE
+ // If your code uses a lot of JUCE classes, then this will obviously save you
+ // a lot of typing, but can be disabled by setting DONT_SET_USING_JUCE_NAMESPACE.
+ using namespace juce;
+#endif
+
+#if ! JUCE_DONT_DECLARE_PROJECTINFO
+namespace ProjectInfo
+{
+    const char* const  projectName    = "SimpleFFTExample";
+    const char* const  versionString  = "1.0.0";
+    const int          versionNumber  = 0x10000;
+}
+#endif
+
+#endif   // __APPHEADERFILE_CGCXPD__

examples/SimpleFFTExample/JuceLibraryCode/ReadMe.txt

@@ -0,0 +1,12 @@
+
+ Important Note!!
+ ================
+
+The purpose of this folder is to contain files that are auto-generated by the Introjucer,
+and ALL files in this folder will be mercilessly DELETED and completely re-written whenever
+the Introjucer saves your project.
+
+Therefore, it's a bad idea to make any manual changes to the files in here, or to
+put any of your own files in here if you don't want to lose them. (Of course you may choose
+to add the folder's contents to your version-control system so that you can re-merge your own
+modifications after the Introjucer has saved its changes).

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_audio_basics/juce_audio_basics.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_audio_basics/juce_audio_basics.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_audio_devices/juce_audio_devices.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_audio_devices/juce_audio_devices.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_audio_formats/juce_audio_formats.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_audio_formats/juce_audio_formats.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_audio_processors/juce_audio_processors.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_audio_processors/juce_audio_processors.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_audio_utils/juce_audio_utils.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_audio_utils/juce_audio_utils.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_core/juce_core.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_core/juce_core.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_data_structures/juce_data_structures.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_data_structures/juce_data_structures.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_events/juce_events.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_events/juce_events.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_graphics/juce_graphics.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_graphics/juce_graphics.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_gui_basics/juce_gui_basics.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_gui_basics/juce_gui_basics.h"
+

examples/SimpleFFTExample/JuceLibraryCode/modules/juce_gui_extra/juce_gui_extra.h

@@ -0,0 +1,5 @@
+// This is an auto-generated file to redirect any included
+// module headers to the correct external folder.
+
+#include "../../../../../modules/juce_gui_extra/juce_gui_extra.h"
+

examples/SimpleFFTExample/SimpleFFTExample.jucer

@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<JUCERPROJECT id="cgcxPd" name="SimpleFFTExample" projectType="guiapp" version="1.0.0"
+              bundleIdentifier="com.yourcompany.SimpleFFTExample" includeBinaryInAppConfig="1"
+              jucerVersion="3.1.1">
+  <MAINGROUP id="rZCHr8" name="SimpleFFTExample">
+    <GROUP id="{8DC23B3F-98AC-AB1C-B26A-E693AF2DF0D2}" name="Source">
+      <FILE id="B1L62H" name="SpectrogramComponent.h" compile="0" resource="0"
+            file="Source/SpectrogramComponent.h"/>
+      <FILE id="uviznd" name="Main.cpp" compile="1" resource="0" file="Source/Main.cpp"/>
+    </GROUP>
+  </MAINGROUP>
+  <EXPORTFORMATS>
+    <XCODE_MAC targetFolder="Builds/MacOSX">
+      <CONFIGURATIONS>
+        <CONFIGURATION name="Debug" osxSDK="default" osxCompatibility="default" osxArchitecture="default"
+                       isDebug="1" optimisation="1" targetName="SimpleFFTExample"/>
+        <CONFIGURATION name="Release" osxSDK="default" osxCompatibility="default" osxArchitecture="default"
+                       isDebug="0" optimisation="3" targetName="SimpleFFTExample"/>
+      </CONFIGURATIONS>
+      <MODULEPATHS>
+        <MODULEPATH id="juce_core" path="../../modules"/>
+        <MODULEPATH id="juce_events" path="../../modules"/>
+        <MODULEPATH id="juce_graphics" path="../../modules"/>
+        <MODULEPATH id="juce_data_structures" path="../../modules"/>
+        <MODULEPATH id="juce_gui_basics" path="../../modules"/>
+        <MODULEPATH id="juce_gui_extra" path="../../modules"/>
+        <MODULEPATH id="juce_audio_basics" path="../../modules"/>
+        <MODULEPATH id="juce_audio_devices" path="../../modules"/>
+        <MODULEPATH id="juce_audio_formats" path="../../modules"/>
+        <MODULEPATH id="juce_audio_processors" path="../../modules"/>
+        <MODULEPATH id="juce_audio_utils" path="../../modules"/>
+      </MODULEPATHS>
+    </XCODE_MAC>
+    <VS2013 targetFolder="Builds/VisualStudio2013">
+      <CONFIGURATIONS>
+        <CONFIGURATION name="Debug" winWarningLevel="4" generateManifest="1" winArchitecture="32-bit"
+                       isDebug="1" optimisation="1" targetName="SimpleFFTExample"/>
+        <CONFIGURATION name="Release" winWarningLevel="4" generateManifest="1" winArchitecture="32-bit"
+                       isDebug="0" optimisation="3" targetName="SimpleFFTExample"/>
+      </CONFIGURATIONS>
+      <MODULEPATHS>
+        <MODULEPATH id="juce_gui_extra" path="../../modules"/>
+        <MODULEPATH id="juce_gui_basics" path="../../modules"/>
+        <MODULEPATH id="juce_graphics" path="../../modules"/>
+        <MODULEPATH id="juce_events" path="../../modules"/>
+        <MODULEPATH id="juce_data_structures" path="../../modules"/>
+        <MODULEPATH id="juce_core" path="../../modules"/>
+        <MODULEPATH id="juce_audio_utils" path="../../modules"/>
+        <MODULEPATH id="juce_audio_processors" path="../../modules"/>
+        <MODULEPATH id="juce_audio_formats" path="../../modules"/>
+        <MODULEPATH id="juce_audio_devices" path="../../modules"/>
+        <MODULEPATH id="juce_audio_basics" path="../../modules"/>
+      </MODULEPATHS>
+    </VS2013>
+  </EXPORTFORMATS>
+  <MODULES>
+    <MODULES id="juce_audio_basics" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_audio_devices" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_audio_formats" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_audio_processors" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_audio_utils" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_core" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_data_structures" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_events" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_graphics" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_gui_basics" showAllCode="1" useLocalCopy="0"/>
+    <MODULES id="juce_gui_extra" showAllCode="1" useLocalCopy="0"/>
+  </MODULES>
+  <JUCEOPTIONS/>
+</JUCERPROJECT>

examples/SimpleFFTExample/Source/Main.cpp

@@ -0,0 +1,80 @@
+/*
+  ==============================================================================
+
+    JUCE demo code - use at your own risk!
+
+  ==============================================================================
+*/
+
+#include "../JuceLibraryCode/JuceHeader.h"
+#include "SpectrogramComponent.h"
+
+
+//==============================================================================
+class SimpleFFTExampleApplication  : public JUCEApplication
+{
+public:
+    //==============================================================================
+    SimpleFFTExampleApplication() {}
+
+    const String getApplicationName() override       { return ProjectInfo::projectName; }
+    const String getApplicationVersion() override    { return ProjectInfo::versionString; }
+    bool moreThanOneInstanceAllowed() override       { return true; }
+
+    //==============================================================================
+    void initialise (const String& /*commandLine*/) override
+    {
+        mainWindow = new MainWindow();
+    }
+
+    void shutdown() override
+    {
+        mainWindow = nullptr; // (deletes our window)
+    }
+
+    //==============================================================================
+    void systemRequestedQuit() override
+    {
+        // This is called when the app is being asked to quit: you can ignore this
+        // request and let the app carry on running, or call quit() to allow the app to close.
+        quit();
+    }
+
+    //==============================================================================
+    /*
+        This class implements the desktop window that contains an instance of
+        our MainContentComponent class.
+    */
+    class MainWindow    : public DocumentWindow
+    {
+    public:
+        MainWindow()  : DocumentWindow (ProjectInfo::projectName,
+                                        Colours::lightgrey,
+                                        DocumentWindow::allButtons)
+        {
+            setUsingNativeTitleBar (true);
+            setContentOwned (new SpectrogramComponent(), true);
+            setResizable (true, true);
+            centreWithSize (getWidth(), getHeight());
+            setVisible (true);
+        }
+
+        void closeButtonPressed() override
+        {
+            // This is called when the user tries to close this window. Here, we'll just
+            // ask the app to quit when this happens, but you can change this to do
+            // whatever you need.
+            JUCEApplication::getInstance()->systemRequestedQuit();
+        }
+
+    private:
+        JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MainWindow)
+    };
+
+private:
+    ScopedPointer<MainWindow> mainWindow;
+};
+
+//==============================================================================
+// This macro generates the main() routine that launches the app.
+START_JUCE_APPLICATION (SimpleFFTExampleApplication)

examples/SimpleFFTExample/Source/SpectrogramComponent.h

@@ -0,0 +1,132 @@
+/*
+  ==============================================================================
+
+    JUCE demo code - use at your own risk!
+
+  ==============================================================================
+*/
+
+
+class SpectrogramComponent   : public AudioAppComponent,
+                               private Timer
+{
+public:
+    SpectrogramComponent()
+        : forwardFFT (fftOrder, false),
+          spectrogramImage (Image::RGB, 512, 512, true),
+          fifoIndex (0),
+          nextFFTBlockReady (false)
+    {
+        setOpaque (true);
+        setAudioChannels (2, 0);  // we want a couple of input channels but no outputs
+        startTimerHz (60);
+        setSize (700, 500);
+    }
+
+    ~SpectrogramComponent()
+    {
+        shutdownAudio();
+    }
+
+    //=======================================================================
+    void prepareToPlay (int /*samplesPerBlockExpected*/, double /*newSampleRate*/) override
+    {
+        // (nothing to do here)
+    }
+
+    void releaseResources() override
+    {
+        // (nothing to do here)
+    }
+
+    void getNextAudioBlock (const AudioSourceChannelInfo& bufferToFill) override
+    {
+        if (bufferToFill.buffer->getNumChannels() > 0)
+        {
+            const float* channelData = bufferToFill.buffer->getWritePointer (0, bufferToFill.startSample);
+
+            for (int i = 0; i < bufferToFill.numSamples; ++i)
+                pushNextSampleIntoFifo (channelData[i]);
+        }
+    }
+
+    //=======================================================================
+    void paint (Graphics& g) override
+    {
+        g.fillAll (Colours::black);
+
+        g.setOpacity (1.0f);
+        g.drawImageWithin (spectrogramImage, 0, 0, getWidth(), getHeight(), RectanglePlacement::stretchToFit);
+    }
+
+    void timerCallback() override
+    {
+        if (nextFFTBlockReady)
+        {
+            drawNextLineOfSpectrogram();
+            nextFFTBlockReady = false;
+            repaint();
+        }
+    }
+
+    void pushNextSampleIntoFifo (float sample) noexcept
+    {
+        // if the fifo contains enough data, set a flag to say
+        // that the next line should now be rendered..
+        if (fifoIndex == fftSize)
+        {
+            if (! nextFFTBlockReady)
+            {
+                zeromem (fftData, sizeof (fftData));
+                memcpy (fftData, fifo, sizeof (fifo));
+                nextFFTBlockReady = true;
+            }
+
+            fifoIndex = 0;
+        }
+
+        fifo[fifoIndex++] = sample;
+    }
+
+    void drawNextLineOfSpectrogram()
+    {
+        const int rightHandEdge = spectrogramImage.getWidth() - 1;
+        const int imageHeight = spectrogramImage.getHeight();
+
+        // first, shuffle our image leftwards by 1 pixel..
+        spectrogramImage.moveImageSection (0, 0, 1, 0, rightHandEdge, imageHeight);
+
+        // then render our FFT data..
+        forwardFFT.performFrequencyOnlyForwardTransform (fftData);
+
+        // find the range of values produced, so we can scale our rendering to
+        // show up the detail clearly
+        Range<float> maxLevel = FloatVectorOperations::findMinAndMax (fftData, fftSize / 2);
+
+        for (int y = 0; y < imageHeight; ++y)
+        {
+            const float skewedProportionY = 1.0f - std::exp (std::log (y / (float) imageHeight) * 0.2f);
+            const int fftDataIndex = jlimit (0, fftSize / 2, (int) (skewedProportionY * fftSize / 2));
+            const float level = jmap (fftData[fftDataIndex], 0.0f, maxLevel.getEnd(), 0.0f, 1.0f);
+
+            spectrogramImage.setPixelAt (rightHandEdge, y, Colour::fromHSV (level, 1.0f, level, 1.0f));
+        }
+    }
+
+    enum
+    {
+        fftOrder = 10,
+        fftSize  = 1 << fftOrder
+    };
+
+private:
+    FFT forwardFFT;
+    Image spectrogramImage;
+
+    float fifo [fftSize];
+    float fftData [2 * fftSize];
+    int fifoIndex;
+    bool nextFFTBlockReady;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SpectrogramComponent)
+};