git subrepo clone --branch=sono6good https://github.com/essej/JUCE.git deps/juce

subrepo:
  subdir:   "deps/juce"
  merged:   "b13f9084e"
upstream:
  origin:   "https://github.com/essej/JUCE.git"
  branch:   "sono6good"
  commit:   "b13f9084e"
git-subrepo:
  version:  "0.4.3"
  origin:   "https://github.com/ingydotnet/git-subrepo.git"
  commit:   "2f68596"

deps/juce/extras/NetworkGraphicsDemo/Source/Demos.h

@@ -0,0 +1,504 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2020 - Raw Material Software Limited
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 6 End-User License
+   Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
+
+   End User License Agreement: www.juce.com/juce-6-licence
+   Privacy Policy: www.juce.com/juce-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
+   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
+   DISCLAIMED.
+
+  ==============================================================================
+*/
+
+
+struct BlankCanvas  : public AnimatedContent
+{
+    String getName() const override      { return "Blank Canvas"; }
+    void reset() override {}
+    void handleTouch (Point<float>) override {}
+    void generateCanvas (Graphics&, SharedCanvasDescription&, Rectangle<float>) override {}
+};
+
+//==============================================================================
+struct GridLines  : public AnimatedContent
+{
+    String getName() const override      { return "Grid Lines"; }
+    void reset() override {}
+    void handleTouch (Point<float>) override {}
+
+    void generateCanvas (Graphics& g, SharedCanvasDescription& canvas, Rectangle<float>) override
+    {
+        auto limits = canvas.getLimits();
+        float lineThickness = 0.1f;
+
+        g.setColour (Colours::blue);
+        g.drawRect (canvas.getLimits(), lineThickness);
+
+        for (float y = limits.getY(); y < limits.getBottom(); y += 2.0f)
+            g.drawLine (limits.getX(), y, limits.getRight(), y, lineThickness);
+
+        for (float x = limits.getX(); x < limits.getRight(); x += 2.0f)
+            g.drawLine (x, limits.getY(), x, limits.getBottom(), lineThickness);
+
+        g.setColour (Colours::darkred);
+        g.drawLine (limits.getX(), limits.getCentreY(), limits.getRight(), limits.getCentreY(), lineThickness);
+        g.drawLine (limits.getCentreX(), limits.getY(), limits.getCentreX(), limits.getBottom(), lineThickness);
+
+        g.setColour (Colours::lightgrey);
+        g.drawLine (limits.getX(), limits.getY(), limits.getRight(), limits.getBottom(), lineThickness);
+        g.drawLine (limits.getX(), limits.getBottom(), limits.getRight(), limits.getY(), lineThickness);
+    }
+};
+
+//==============================================================================
+struct BackgroundLogo  : public AnimatedContent
+{
+    BackgroundLogo()
+    {
+        static const char logoData[] = R"blahblah(
+            <svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+                 viewBox="0 0 239.2 239.2" enable-background="new 0 0 239.2 239.2" xml:space="preserve">
+            <path fill="#6CC04A" d="M118.8,201.3c-44.6,0-81-36.3-81-81s36.3-81,81-81s81,36.3,81,81S163.4,201.3,118.8,201.3z M118.8,44.8c-41.7,0-75.6,33.9-75.6,75.6s33.9,75.6,75.6,75.6s75.6-33.9,75.6-75.6S160.4,44.8,118.8,44.8z"/>
+            <path fill="#3B5CAD" d="M182.6,117.6c1.4,0,2.7-0.5,3.7-1.5c1.1-1.1,1.6-2.5,1.4-4c-1.5-12.7-6.5-24.7-14.4-34.8c-1-1.2-2.3-1.9-3.8-1.9c-1.3,0-2.6,0.5-3.6,1.5l-39,39c-0.6,0.6-0.2,1.6,0.7,1.6L182.6,117.6z"/>
+            <path fill="#E73E51" d="M169.5,165.2L169.5,165.2c1.5,0,2.8-0.7,3.8-1.9c7.9-10.1,12.9-22.1,14.4-34.8c0.2-1.5-0.3-2.9-1.4-4c-1-1-2.3-1.5-3.7-1.5l-55,0c-0.9,0-1.3,1-0.7,1.6l39,39C166.9,164.7,168.2,165.2,169.5,165.2z"/>
+            <path fill="#E67E3C" d="M122.9,188L122.9,188c1,1,2.5,1.5,4,1.3c12.7-1.5,24.8-6.5,34.8-14.4c1.2-0.9,1.8-2.3,1.9-3.8c0-1.4-0.6-2.7-1.6-3.7l-38.9-38.9c-0.6-0.6-1.6-0.2-1.6,0.7l0,55.2C121.4,185.8,122,187,122.9,188z"/>
+            <path fill="#F0E049" d="M68,75.4c-1.5,0-2.8,0.7-3.8,1.9c-7.9,10.1-12.9,22.1-14.4,34.8c-0.2,1.5,0.3,2.9,1.4,4c1,1,2.3,1.5,3.7,1.5l55,0c0.9,0,1.3-1,0.7-1.6l-39-39C70.6,76,69.3,75.4,68,75.4z"/>
+            <path fill="#D5D755" d="M114.6,52.7c-1-1-2.5-1.5-4-1.3c-12.7,1.5-24.8,6.5-34.8,14.4c-1.2,0.9-1.8,2.3-1.9,3.8c0,1.4,0.6,2.7,1.6,3.7l38.9,38.9c0.6,0.6,1.6,0.2,1.6-0.7l0-55.2C116.1,54.9,115.5,53.6,114.6,52.7z"/>
+            <path fill="#9CB6D3" d="M163.7,69.6c0-1.5-0.7-2.8-1.9-3.8c-10.1-7.9-22.1-12.9-34.8-14.4c-1.5-0.2-2.9,0.3-4,1.4c-1,1-1.5,2.3-1.5,3.7l0,55c0,0.9,1,1.3,1.6,0.7l39-39C163.1,72.1,163.7,70.9,163.7,69.6z"/>
+            <path fill="#F5BD47" d="M109.9,123l-55,0c-1.4,0-2.7,0.5-3.7,1.5c-1.1,1.1-1.6,2.5-1.4,4c1.5,12.7,6.5,24.7,14.4,34.8c1,1.2,2.3,1.9,3.8,1.9c1.3,0,2.6-0.5,3.5-1.5c0,0,0,0,0,0l39-39C111.2,124,110.8,123,109.9,123z"/>
+            <path fill="#F19F53" d="M114.4,128.5l-38.9,38.9c-1,1-1.6,2.3-1.6,3.7c0,1.5,0.7,2.9,1.9,3.8c10,7.9,22.1,12.9,34.8,14.4c1.6,0.2,3-0.3,4-1.3c0.9-0.9,1.4-2.2,1.4-3.6c0,0,0,0,0,0l0-55.2C116.1,128.3,115,127.9,114.4,128.5z"/>
+            </svg>
+            )blahblah";
+
+        logo = Drawable::createFromSVG (*parseXML (logoData));
+    }
+
+    String getName() const override      { return "Background Image"; }
+    void reset() override {}
+    void handleTouch (Point<float>) override {}
+
+    void generateCanvas (Graphics& g, SharedCanvasDescription& canvas, Rectangle<float>) override
+    {
+        logo->drawWithin (g, canvas.getLimits().reduced (3.0f), RectanglePlacement (RectanglePlacement::centred), 0.6f);
+    }
+
+    std::unique_ptr<Drawable> logo;
+};
+
+//==============================================================================
+struct FlockDemo  : public BackgroundLogo
+{
+    String getName() const override      { return "Flock"; }
+
+    void setNumBirds (int numBirds)
+    {
+        BackgroundLogo::reset();
+
+        birds.clear();
+
+        for (int i = numBirds; --i >= 0;)
+            birds.add ({});
+
+        centreOfGravity = {};
+        lastGravityMove = {};
+        fakeMouseTouchLengthToRun = 0;
+        fakeMouseTouchPosition = {};
+        fakeMouseTouchVelocity = {};
+    }
+
+    void reset() override
+    {
+        BackgroundLogo::reset();
+        setNumBirds (100);
+    }
+
+    void generateCanvas (Graphics& g, SharedCanvasDescription& canvas, Rectangle<float> activeArea) override
+    {
+        BackgroundLogo::generateCanvas (g, canvas, activeArea);
+
+        if (Time::getCurrentTime() > lastGravityMove + RelativeTime::seconds (0.5))
+        {
+            if (fakeMouseTouchLengthToRun > 0)
+            {
+                --fakeMouseTouchLengthToRun;
+                fakeMouseTouchPosition += fakeMouseTouchVelocity;
+                centreOfGravity = fakeMouseTouchPosition;
+            }
+            else
+            {
+                centreOfGravity = {};
+
+                if (rng.nextInt (300) == 2 && canvas.clients.size() > 0)
+                {
+                    fakeMouseTouchLengthToRun = 50;
+                    fakeMouseTouchPosition = canvas.clients.getReference (rng.nextInt (canvas.clients.size())).centre;
+                    fakeMouseTouchVelocity = { rng.nextFloat() * 0.3f - 0.15f,
+                                               rng.nextFloat() * 0.3f - 0.15f };
+                }
+            }
+        }
+
+        g.setColour (Colours::white.withAlpha (0.2f));
+
+        if (! centreOfGravity.isOrigin())
+            g.fillEllipse (centreOfGravity.getX() - 1.0f, centreOfGravity.getY() - 1.0f, 2.0f, 2.0f);
+
+        for (int i = 0; i < birds.size(); ++i)
+            for (int j = i + 1; j < birds.size(); ++j)
+                attractBirds (birds.getReference(i), birds.getReference(j));
+
+        for (auto& b : birds)
+        {
+            if (! centreOfGravity.isOrigin())
+                b.move (centreOfGravity, 0.4f);
+
+            b.update();
+            b.draw (g);
+            b.bounceOffEdges (canvas.getLimits().expanded (1.0f));
+        }
+
+        for (int i = rings.size(); --i >= 0;)
+        {
+            if (rings.getReference(i).update())
+                rings.getReference(i).draw (g);
+            else
+                rings.remove (i);
+        }
+    }
+
+    bool isRingNear (Point<float> p) const
+    {
+        for (auto& r : rings)
+            if (r.centre.getDistanceFrom (p) < 1.0f)
+                return true;
+
+        return false;
+    }
+
+    void handleTouch (Point<float> position) override
+    {
+        lastGravityMove = Time::getCurrentTime();
+        centreOfGravity = position;
+        fakeMouseTouchLengthToRun = 0;
+
+        if (! isRingNear (position))
+            rings.add ({ position, 1.0f, 0.5f });
+    }
+
+    //==============================================================================
+    struct Bird
+    {
+        Bird()
+        {
+            Random randGen;
+            pos.x = randGen.nextFloat() * 10.0f - 5.0f;
+            pos.y = randGen.nextFloat() * 10.0f - 5.0f;
+            velocity.x = randGen.nextFloat() * 0.001f;
+            velocity.y = randGen.nextFloat() * 0.001f;
+
+            colour = Colour::fromHSV (randGen.nextFloat(), 0.2f, 0.9f, randGen.nextFloat() * 0.4f + 0.2f);
+
+            shape.addTriangle (0.0f, 0.0f, -0.3f, 1.0f, 0.3f, 1.0f);
+            shape = shape.createPathWithRoundedCorners (0.2f);
+
+            shape.applyTransform (AffineTransform::scale (randGen.nextFloat() + 1.0f));
+        }
+
+        Point<float> pos, velocity, acc;
+        Colour colour;
+        Path shape;
+
+        void move (Point<float> target, float strength)
+        {
+            auto r = target - pos;
+            float rSquared = jmax (0.1f, (r.x * r.x) + (r.y * r.y));
+
+            if (rSquared > 1.0f)
+                velocity += (r * strength / rSquared);
+
+            acc = {};
+        }
+
+        void accelerate (Point<float> acceleration)
+        {
+            acc += acceleration;
+        }
+
+        void bounceOffEdges (Rectangle<float> limits)
+        {
+            if (pos.x < limits.getX())      { velocity.x =  std::abs (velocity.x); acc = {}; }
+            if (pos.x > limits.getRight())  { velocity.x = -std::abs (velocity.x); acc = {}; }
+            if (pos.y < limits.getY())      { velocity.y =  std::abs (velocity.y); acc = {}; }
+            if (pos.y > limits.getBottom()) { velocity.y = -std::abs (velocity.y); acc = {}; }
+        }
+
+        void update()
+        {
+            velocity += acc;
+
+            float length = velocity.getDistanceFromOrigin();
+            const float maxSpeed = 0.5f;
+
+            if (length > maxSpeed)
+                velocity = getVectorWithLength (velocity, maxSpeed);
+
+            pos += velocity;
+        }
+
+        void draw (Graphics& g)
+        {
+            g.setColour (colour);
+            g.fillPath (shape, AffineTransform::rotation (Point<float>().getAngleToPoint (velocity)).translated (pos));
+        }
+    };
+
+    static Point<float> getVectorWithLength (Point<float> v, float newLength)
+    {
+        return v * (newLength / v.getDistanceFromOrigin());
+    }
+
+    static void attractBirds (Bird& b1, Bird& b2)
+    {
+        auto delta = b1.pos - b2.pos;
+
+        const float zoneRadius = 10.0f;
+        const float low = 0.4f;
+        const float high = 0.65f;
+        const float strength = 0.01f;
+
+        const float distanceSquared = (delta.x * delta.x) * (delta.y * delta.y);
+
+        if (distanceSquared < zoneRadius * zoneRadius && distanceSquared > 0.01f)
+        {
+            float proportion = distanceSquared / (zoneRadius * zoneRadius);
+
+            if (proportion < low)
+            {
+                const float F = (low / proportion - 1.0f) * strength * 0.003f;
+                delta = getVectorWithLength (delta, F);
+
+                b1.accelerate (delta);
+                b2.accelerate (-delta);
+            }
+            else if (proportion < high)
+            {
+                const float regionSize = high - low;
+                const float adjustedProportion = (proportion - low) / regionSize;
+                const float F = (0.5f - std::cos (adjustedProportion * MathConstants<float>::twoPi) * 0.5f + 0.5f) * strength;
+
+                b1.accelerate (getVectorWithLength (b2.velocity, F));
+                b2.accelerate (getVectorWithLength (b1.velocity, F));
+            }
+            else
+            {
+                const float regionSize = 1.0f - high;
+                const float adjustedProportion = (proportion - high) / regionSize;
+                const float F = (0.5f - std::cos (adjustedProportion * MathConstants<float>::twoPi) * 0.5f + 0.5f) * strength;
+                delta = getVectorWithLength (delta, F);
+
+                b1.accelerate (-delta);
+                b2.accelerate (delta);
+            }
+        }
+    }
+
+    Random rng;
+    Array<Bird> birds;
+    Point<float> centreOfGravity;
+    Time lastGravityMove;
+
+    int fakeMouseTouchLengthToRun = 0;
+    Point<float> fakeMouseTouchPosition, fakeMouseTouchVelocity;
+
+    //==============================================================================
+    struct Ring
+    {
+        Point<float> centre;
+        float diameter, opacity;
+
+        bool update()
+        {
+            diameter += 0.7f;
+            opacity -= 0.01f;
+
+            return opacity > 0;
+        }
+
+        void draw (Graphics& g)
+        {
+            const float thickness = 0.2f;
+
+            auto r = Rectangle<float> (diameter, diameter).withCentre (centre);
+
+            Path p;
+            p.addEllipse (r);
+            p.addEllipse (r.reduced (thickness));
+            p.setUsingNonZeroWinding (false);
+
+            g.setColour (Colours::white.withAlpha (opacity));
+            g.fillPath (p);
+
+        }
+    };
+
+    Array<Ring> rings;
+};
+
+//==============================================================================
+struct FlockWithText  : public FlockDemo
+{
+    FlockWithText()
+    {
+        messages.add ("JUCE is our cross-platform C++ framework\n\n"
+                      "In this demo, the same C++ app is running natively on NUMDEVICES devices,\n"
+                      "which are sharing their graphic state via the network");
+
+        messages.add ("No other libraries were needed to create this demo.\n"
+                      "JUCE provides thousands of classes for cross-platform GUI,\n"
+                      "audio, networking, data-structures and many other common tasks");
+
+        messages.add ("As well as a code library, JUCE provides tools for managing\n"
+                      "cross-platform projects that are built with Xcode,\n"
+                      "Visual Studio, Android Studio, GCC and other compilers");
+
+        messages.add ("JUCE can be used to build desktop or mobile apps, and also\n"
+                      "audio plug-ins in the VST2, VST3, AudioUnit, AAX and RTAS formats");
+    }
+
+    String getName() const override      { return "Flock with text"; }
+
+    void reset() override
+    {
+        FlockDemo::reset();
+
+        currentMessage = 0;
+        currentMessageStart = {};
+        clientIndex = 0;
+    }
+
+    void generateCanvas (Graphics& g, SharedCanvasDescription& canvas, Rectangle<float> activeArea) override
+    {
+        FlockDemo::generateCanvas (g, canvas, activeArea);
+
+        const float textSize = 0.5f; // inches
+        const float textBlockWidth = 20.0f;  // inches
+
+        tick();
+
+        Graphics::ScopedSaveState ss (g);
+        const float scale = 20.0f; // scaled to allow the fonts to use more reasonable sizes
+        g.addTransform (AffineTransform::scale (1.0f / scale));
+
+        String text = String (messages[currentMessage]).replace ("NUMDEVICES", String (canvas.clients.size()));
+
+        AttributedString as;
+        as.append (text, Font (textSize * scale), Colour (0x80ffffff).withMultipliedAlpha (alpha));
+
+        as.setJustification (Justification::centred);
+        auto middle = canvas.clients[clientIndex % canvas.clients.size()].centre * scale;
+        as.draw (g, Rectangle<float> (textBlockWidth * scale, textBlockWidth * scale).withCentre (middle));
+    }
+
+    void tick()
+    {
+        const double displayTimeSeconds = 5.0;
+        const double fadeTimeSeconds = 1.0;
+
+        Time now = Time::getCurrentTime();
+        const double secondsSinceStart = (now - currentMessageStart).inSeconds();
+
+        if (secondsSinceStart > displayTimeSeconds)
+        {
+            currentMessageStart = now;
+            currentMessage = (currentMessage + 1) % messages.size();
+            ++clientIndex;
+            alpha = 0;
+        }
+        else if (secondsSinceStart > displayTimeSeconds - fadeTimeSeconds)
+        {
+            alpha = (float) jlimit (0.0, 1.0, (displayTimeSeconds - secondsSinceStart) / fadeTimeSeconds);
+        }
+        else if (secondsSinceStart < fadeTimeSeconds)
+        {
+            alpha = (float) jlimit (0.0, 1.0, secondsSinceStart / fadeTimeSeconds);
+        }
+    }
+
+    StringArray messages;
+    int currentMessage = 0, clientIndex = 0;
+    float alpha = 0;
+    Point<float> centre;
+    Time currentMessageStart;
+};
+
+//==============================================================================
+struct SmallFlock  : public FlockDemo
+{
+    String getName() const override      { return "Small Flock"; }
+
+    void reset() override
+    {
+        setNumBirds (20);
+    }
+};
+
+//==============================================================================
+struct BigFlock  : public FlockDemo
+{
+    String getName() const override      { return "Big Flock"; }
+
+    void reset() override
+    {
+        setNumBirds (200);
+    }
+};
+
+//==============================================================================
+template <int numHorizontalLogos>
+struct MultiLogo  : public BackgroundLogo
+{
+    String getName() const override      { return "Multi-Logo " + String ((int) numHorizontalLogos); }
+
+    void generateCanvas (Graphics& g, SharedCanvasDescription& canvas, Rectangle<float>) override
+    {
+        float indent = 0.5f;
+        float logoSize = canvas.getLimits().getWidth() / numHorizontalLogos;
+        auto limits = canvas.getLimits();
+
+        for (float x = limits.getX(); x < limits.getRight(); x += logoSize)
+        {
+            for (float y = limits.getY(); y < limits.getBottom(); y += logoSize)
+            {
+                logo->drawWithin (g, Rectangle<float> (x, y, logoSize, logoSize).reduced (indent),
+                                  RectanglePlacement (RectanglePlacement::centred), 0.5f);
+            }
+        }
+    }
+};
+
+//==============================================================================
+void createAllDemos (OwnedArray<AnimatedContent>& demos)
+{
+    demos.add (new FlockDemo());
+    demos.add (new FlockWithText());
+    demos.add (new SmallFlock());
+    demos.add (new BigFlock());
+    demos.add (new BackgroundLogo());
+    demos.add (new MultiLogo<5>());
+    demos.add (new MultiLogo<10>());
+    demos.add (new GridLines());
+    demos.add (new BlankCanvas());
+}

deps/juce/extras/NetworkGraphicsDemo/Source/Main.cpp

@@ -0,0 +1,157 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2020 - Raw Material Software Limited
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 6 End-User License
+   Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
+
+   End User License Agreement: www.juce.com/juce-6-licence
+   Privacy Policy: www.juce.com/juce-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
+   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
+   DISCLAIMED.
+
+  ==============================================================================
+*/
+
+#include <JuceHeader.h>
+
+namespace
+{
+    String getBroadcastIPAddress()
+    {
+        return IPAddress::getLocalAddress().toString().upToLastOccurrenceOf (".", false, false) + ".255";
+    }
+
+    static const int masterPortNumber = 9001;  // the UDP port the master sends on / the clients receive.
+    static const int clientPortNumber = 9002;  // the UDP port the clients send on / the master receives.
+
+    static const String canvasStateOSCAddress = "/juce/nfd/canvasState";
+    static const String newClientOSCAddress   = "/juce/nfd/newClient";
+    static const String userInputOSCAddress   = "/juce/nfd/userInput";
+}
+
+#include "SharedCanvas.h"
+#include "SlaveComponent.h"
+#include "Demos.h"
+#include "MasterComponent.h"
+
+
+//==============================================================================
+class NetworkGraphicsDemoApplication  : public JUCEApplication
+{
+public:
+    NetworkGraphicsDemoApplication()  : properties (getPropertyFileOptions())
+    {}
+
+    const String getApplicationName() override           { return ProjectInfo::projectName; }
+    const String getApplicationVersion() override        { return ProjectInfo::versionString; }
+    bool moreThanOneInstanceAllowed() override           { return true; }
+    void anotherInstanceStarted (const String&) override {}
+
+    //==============================================================================
+    void initialise (const String& commandLine) override
+    {
+       #if ! JUCE_IOS && ! JUCE_ANDROID
+        // Run as the master if we have a command-line flag "master" or if the exe itself
+        // has been renamed to include the word "master"..
+        bool isMaster = commandLine.containsIgnoreCase ("master")
+                          || File::getSpecialLocation (File::currentApplicationFile)
+                                .getFileName().containsIgnoreCase ("master");
+
+        if (isMaster)
+            mainWindows.add (new MainWindow (properties));
+       #endif
+
+        mainWindows.add (new MainWindow (properties, 0));
+
+        Desktop::getInstance().setScreenSaverEnabled (false);
+    }
+
+    void shutdown() override
+    {
+        mainWindows.clear();
+        properties.saveIfNeeded();
+    }
+
+    void systemRequestedQuit() override
+    {
+        quit();
+    }
+
+    //==============================================================================
+    struct MainWindow    : public DocumentWindow
+    {
+        explicit MainWindow (PropertiesFile& props)
+            : DocumentWindow ("JUCE Networked Graphics Demo - Master", Colours::white, DocumentWindow::allButtons)
+        {
+            setUsingNativeTitleBar (true);
+            setContentOwned (new MasterContentComponent (props), true);
+            setBounds (100, 50, getWidth(), getHeight());
+            setResizable (true, false);
+            setVisible (true);
+
+            glContext.attachTo (*this);
+        }
+
+        MainWindow (PropertiesFile& props, int windowIndex)
+            : DocumentWindow ("JUCE Networked Graphics Demo", Colours::black, DocumentWindow::allButtons)
+        {
+            setUsingNativeTitleBar (true);
+            setContentOwned (new SlaveCanvasComponent (props, windowIndex), true);
+            setBounds (500, 100, getWidth(), getHeight());
+            setResizable (true, false);
+            setVisible (true);
+
+           #if ! JUCE_IOS
+            glContext.attachTo (*this);
+           #endif
+
+           #if JUCE_IOS || JUCE_ANDROID
+            setFullScreen (true);
+           #endif
+        }
+
+        ~MainWindow() override
+        {
+            glContext.detach();
+        }
+
+        void closeButtonPressed() override
+        {
+            JUCEApplication::getInstance()->systemRequestedQuit();
+        }
+
+        OpenGLContext glContext;
+
+        JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MainWindow)
+    };
+
+    static PropertiesFile::Options getPropertyFileOptions()
+    {
+        PropertiesFile::Options o;
+        o.applicationName = "JUCE Network Graphics Demo";
+        o.filenameSuffix = ".settings";
+        o.folderName = "JUCE Network Graphics Demo";
+        o.osxLibrarySubFolder = "Application Support/JUCE Network Graphics Demo";
+        o.millisecondsBeforeSaving = 2000;
+        return o;
+    }
+
+    PropertiesFile properties;
+    OwnedArray<MainWindow> mainWindows;
+};
+
+
+//==============================================================================
+// This macro generates the main() routine that launches the app.
+START_JUCE_APPLICATION (NetworkGraphicsDemoApplication)

deps/juce/extras/NetworkGraphicsDemo/Source/MasterComponent.h

@@ -0,0 +1,422 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2020 - Raw Material Software Limited
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 6 End-User License
+   Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
+
+   End User License Agreement: www.juce.com/juce-6-licence
+   Privacy Policy: www.juce.com/juce-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
+   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
+   DISCLAIMED.
+
+  ==============================================================================
+*/
+
+
+/**
+    Runs the master node, calls the demo to update the canvas, broadcasts those changes
+    out to slaves, and shows a view of all the clients to allow them to be dragged around.
+*/
+struct MasterContentComponent  : public Component,
+                                 private Timer,
+                                 private OSCSender,
+                                 private OSCReceiver,
+                                 private OSCReceiver::Listener<OSCReceiver::MessageLoopCallback>
+{
+    MasterContentComponent (PropertiesFile& props)
+        : properties (props)
+    {
+        setWantsKeyboardFocus (true);
+        createAllDemos (demos);
+        setContent (0);
+
+        setSize ((int) (15.0f * currentCanvas.getLimits().getWidth()),
+                 (int) (15.0f * currentCanvas.getLimits().getHeight()));
+
+        if (! OSCSender::connect (getBroadcastIPAddress(), masterPortNumber))
+            error = "Master app OSC sender: network connection error.";
+
+        if (! OSCReceiver::connect (clientPortNumber))
+            error = "Master app OSC receiver: network connection error.";
+
+        OSCReceiver::addListener (this);
+
+        startTimerHz (30);
+    }
+
+    ~MasterContentComponent() override
+    {
+        OSCReceiver::removeListener (this);
+    }
+
+    //==============================================================================
+    struct Client
+    {
+        String name, ipAddress;
+        float widthInches, heightInches;
+        Point<float> centre; // in inches
+        float scaleFactor;
+    };
+
+    Array<Client> clients;
+
+    void addClient (String name, String ipAddress, String areaDescription)
+    {
+        auto area = Rectangle<float>::fromString (areaDescription);
+
+        if (auto c = getClient (name))
+        {
+            c->ipAddress = ipAddress;
+            c->widthInches = area.getWidth();
+            c->heightInches = area.getHeight();
+            return;
+        }
+
+        DBG (name + "   "  + ipAddress);
+
+        removeClient (name);
+        clients.add ({ name, ipAddress, area.getWidth(), area.getHeight(), {}, 1.0f });
+
+        String lastX = properties.getValue ("lastX_" + name);
+        String lastY = properties.getValue ("lastY_" + name);
+        String lastScale = properties.getValue ("scale_" + name);
+
+        if (lastX.isEmpty() || lastY.isEmpty())
+            setClientCentre (name, { Random().nextFloat() * 10.0f,
+                                     Random().nextFloat() * 10.0f });
+        else
+            setClientCentre (name, Point<float> (lastX.getFloatValue(),
+                                                 lastY.getFloatValue()));
+
+        if (lastScale.isNotEmpty())
+            setClientScale (name, lastScale.getFloatValue());
+        else
+            setClientScale (name, 1.0f);
+
+        updateDeviceComponents();
+    }
+
+    void removeClient (String name)
+    {
+        for (int i = clients.size(); --i >= 0;)
+            if (clients.getReference (0).name == name)
+                clients.remove (i);
+
+        updateDeviceComponents();
+    }
+
+    void setClientCentre (const String& name, Point<float> newCentre)
+    {
+        if (auto c = getClient (name))
+        {
+            newCentre = currentCanvas.getLimits().getConstrainedPoint (newCentre);
+            c->centre = newCentre;
+
+            properties.setValue ("lastX_" + name, String (newCentre.x));
+            properties.setValue ("lastY_" + name, String (newCentre.y));
+
+            startTimer (1);
+        }
+    }
+
+    float getClientScale (const String& name) const
+    {
+        if (auto c = getClient (name))
+            return c->scaleFactor;
+
+        return 1.0f;
+    }
+
+    void setClientScale (const String& name, float newScale)
+    {
+        if (auto c = getClient (name))
+        {
+            c->scaleFactor = jlimit (0.5f, 2.0f, newScale);
+            properties.setValue ("scale_" + name, String (newScale));
+        }
+    }
+
+    Point<float> getClientCentre (const String& name) const
+    {
+        if (auto c = getClient (name))
+            return c->centre;
+
+        return {};
+    }
+
+    Rectangle<float> getClientArea (const String& name) const
+    {
+        if (auto c = getClient (name))
+            return Rectangle<float> (c->widthInches, c->heightInches)
+                     .withCentre (c->centre);
+
+        return {};
+    }
+
+    Rectangle<float> getActiveCanvasArea() const
+    {
+        Rectangle<float> r;
+
+        if (clients.size() > 0)
+            r = Rectangle<float> (1.0f, 1.0f).withCentre (clients.getReference (0).centre);
+
+        for (int i = 1; i < clients.size(); ++i)
+            r = r.getUnion (Rectangle<float> (1.0f, 1.0f).withCentre (clients.getReference (i).centre));
+
+        return r.expanded (6.0f);
+    }
+
+    int getContentIndex() const
+    {
+        return demos.indexOf (content);
+    }
+
+    void setContent (int demoIndex)
+    {
+        content = demos[demoIndex];
+
+        if (content != nullptr)
+            content->reset();
+    }
+
+    bool keyPressed (const KeyPress& key) override
+    {
+        if (key == KeyPress::spaceKey || key == KeyPress::rightKey || key == KeyPress::downKey)
+        {
+            setContent ((getContentIndex() + 1) % demos.size());
+            return true;
+        }
+
+        if (key == KeyPress::upKey || key == KeyPress::leftKey)
+        {
+            setContent ((getContentIndex() + demos.size() - 1) % demos.size());
+            return true;
+        }
+
+        return Component::keyPressed (key);
+    }
+
+private:
+    //==============================================================================
+    void paint (Graphics& g) override
+    {
+        g.fillAll (Colours::black);
+
+        currentCanvas.draw (g, getLocalBounds().toFloat(), currentCanvas.getLimits());
+
+        if (error.isNotEmpty())
+        {
+            g.setColour (Colours::red);
+            g.setFont (20.0f);
+            g.drawText (error, getLocalBounds().reduced (10).removeFromBottom (80),
+                        Justification::centredRight, true);
+        }
+
+        if (content != nullptr)
+        {
+            g.setColour (Colours::white);
+            g.setFont (17.0f);
+            g.drawText ("Demo: " + content->getName(),
+                        getLocalBounds().reduced (10).removeFromTop (30),
+                        Justification::centredLeft, true);
+        }
+    }
+
+    void resized() override
+    {
+        updateDeviceComponents();
+    }
+
+    void updateDeviceComponents()
+    {
+        for (int i = devices.size(); --i >= 0;)
+            if (getClient (devices.getUnchecked(i)->getName()) == nullptr)
+                devices.remove (i);
+
+        for (const auto& c : clients)
+            if (getDeviceComponent (c.name) == nullptr)
+                addAndMakeVisible (devices.add (new DeviceComponent (*this, c.name)));
+
+        for (auto d : devices)
+            d->setBounds (virtualSpaceToLocal (getClientArea (d->getName())).getSmallestIntegerContainer());
+    }
+
+    Point<float> virtualSpaceToLocal (Point<float> p) const
+    {
+        auto total = currentCanvas.getLimits();
+
+        return { (float) getWidth()  * (p.x - total.getX()) / total.getWidth(),
+                 (float) getHeight() * (p.y - total.getY()) / total.getHeight() };
+    }
+
+    Rectangle<float> virtualSpaceToLocal (Rectangle<float> p) const
+    {
+        return { virtualSpaceToLocal (p.getTopLeft()),
+                 virtualSpaceToLocal (p.getBottomRight()) };
+    }
+
+    Point<float> localSpaceToVirtual (Point<float> p) const
+    {
+        auto total = currentCanvas.getLimits();
+
+        return { total.getX() + total.getWidth()  * (p.x / (float) getWidth()),
+                 total.getY() + total.getHeight() * (p.y / (float) getHeight()) };
+    }
+
+    //==============================================================================
+    struct DeviceComponent  : public Component
+    {
+        DeviceComponent (MasterContentComponent& e, String name)
+            : Component (name), editor (e)
+        {
+            setMouseCursor (MouseCursor::DraggingHandCursor);
+        }
+
+        void paint (Graphics& g) override
+        {
+            g.fillAll (Colours::blue.withAlpha (0.4f));
+
+            g.setColour (Colours::white);
+            g.setFont (11.0f);
+            g.drawFittedText (getName(), getLocalBounds(), Justification::centred, 2);
+        }
+
+        void mouseDown (const MouseEvent&) override
+        {
+            dragStartLocation = editor.getClientCentre (getName());
+        }
+
+        void mouseDrag (const MouseEvent& e) override
+        {
+            editor.setClientCentre (getName(), dragStartLocation
+                                                + editor.localSpaceToVirtual (e.getPosition().toFloat())
+                                                - editor.localSpaceToVirtual (e.getMouseDownPosition().toFloat()));
+        }
+
+        void mouseWheelMove (const MouseEvent&, const MouseWheelDetails& e) override
+        {
+            editor.setClientScale (getName(), editor.getClientScale (getName()) + 0.1f * e.deltaY);
+        }
+
+        void mouseDoubleClick (const MouseEvent&) override
+        {
+            editor.setClientScale (getName(), 1.0f);
+        }
+
+        MasterContentComponent& editor;
+        Point<float> dragStartLocation;
+        Rectangle<float> clientArea;
+    };
+
+    DeviceComponent* getDeviceComponent (const String& name) const
+    {
+        for (auto d : devices)
+            if (d->getName() == name)
+                return d;
+
+        return nullptr;
+    }
+
+    //==============================================================================
+    void broadcastNewCanvasState (const MemoryBlock& canvasData)
+    {
+        BlockPacketiser packetiser;
+        packetiser.createBlocksFromData (canvasData, 1000);
+
+        for (const auto& client : clients)
+            for (auto& b : packetiser.blocks)
+                sendToIPAddress (client.ipAddress, masterPortNumber, canvasStateOSCAddress, b);
+    }
+
+    void timerCallback() override
+    {
+        startTimerHz (30);
+
+        currentCanvas.reset();
+        updateCanvasInfo (currentCanvas);
+
+        {
+            std::unique_ptr<CanvasGeneratingContext> context (new CanvasGeneratingContext (currentCanvas));
+            Graphics g (*context);
+
+            if (content != nullptr)
+                content->generateCanvas (g, currentCanvas, getActiveCanvasArea());
+        }
+
+        broadcastNewCanvasState (currentCanvas.toMemoryBlock());
+
+        updateDeviceComponents();
+        repaint();
+    }
+
+    void updateCanvasInfo (SharedCanvasDescription& canvas)
+    {
+        canvas.backgroundColour = Colours::black;
+
+        for (const auto& c : clients)
+            canvas.clients.add ({ c.name, c.centre, c.scaleFactor });
+    }
+
+    const Client* getClient (const String& name) const
+    {
+        for (auto& c : clients)
+            if (c.name == name)
+                return &c;
+
+        return nullptr;
+    }
+
+    Client* getClient (const String& name)
+    {
+        return const_cast<Client*> (static_cast<const MasterContentComponent&> (*this).getClient (name));
+    }
+
+    //==============================================================================
+    void oscMessageReceived (const OSCMessage& message) override
+    {
+        auto address = message.getAddressPattern();
+
+        if (address.matches (newClientOSCAddress))       newClientOSCMessageReceived (message);
+        else if (address.matches (userInputOSCAddress))  userInputOSCMessageReceived (message);
+    }
+
+    void newClientOSCMessageReceived (const OSCMessage& message)
+    {
+        if (message.isEmpty() || ! message[0].isString())
+            return;
+
+        StringArray tokens = StringArray::fromTokens (message[0].getString(), ":", "");
+        addClient (tokens[0], tokens[1], tokens[2]);
+    }
+
+    void userInputOSCMessageReceived (const OSCMessage& message)
+    {
+        if (message.size() == 3 && message[0].isString() && message[1].isFloat32() && message[2].isFloat32())
+        {
+            content->handleTouch ({ message[1].getFloat32(),
+                                    message[2].getFloat32() });
+        }
+    }
+
+    //==============================================================================
+    AnimatedContent* content = nullptr;
+    PropertiesFile& properties;
+    OwnedArray<DeviceComponent> devices;
+    SharedCanvasDescription currentCanvas;
+    String error;
+
+    OwnedArray<AnimatedContent> demos;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MasterContentComponent)
+};

deps/juce/extras/NetworkGraphicsDemo/Source/SharedCanvas.h

@@ -0,0 +1,527 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2020 - Raw Material Software Limited
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 6 End-User License
+   Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
+
+   End User License Agreement: www.juce.com/juce-6-licence
+   Privacy Policy: www.juce.com/juce-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
+   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
+   DISCLAIMED.
+
+  ==============================================================================
+*/
+
+
+/**
+    This scene description is broadcast to all the clients, and contains a list of all
+    the clients involved, as well as the set of shapes to be drawn.
+
+    Each client will draw the part of the path that lies within its own area. It can
+    find its area by looking at the list of clients contained in this structure.
+
+    All the path coordinates are roughly in units of inches, and devices will convert
+    this to pixels based on their screen size and DPI
+*/
+struct SharedCanvasDescription
+{
+    SharedCanvasDescription() {}
+
+    Colour backgroundColour = Colours::black;
+
+    struct ColouredPath
+    {
+        Path path;
+        FillType fill;
+    };
+
+    Array<ColouredPath> paths;
+
+    struct ClientArea
+    {
+        String name;
+        Point<float> centre; // in inches
+        float scaleFactor; // extra scaling
+    };
+
+    Array<ClientArea> clients;
+
+    //==============================================================================
+    void reset()
+    {
+        paths.clearQuick();
+        clients.clearQuick();
+    }
+
+    void swapWith (SharedCanvasDescription& other)
+    {
+        std::swap (backgroundColour, other.backgroundColour);
+        paths.swapWith (other.paths);
+        clients.swapWith (other.clients);
+    }
+
+    // This is a fixed size that represents the overall canvas limits that
+    // content should lie within
+    Rectangle<float> getLimits() const
+    {
+        float inchesX = 60.0f;
+        float inchesY = 30.0f;
+
+        return { inchesX * -0.5f, inchesY * -0.5f, inchesX, inchesY };
+    }
+
+    //==============================================================================
+    void draw (Graphics& g, Rectangle<float> targetArea, Rectangle<float> clientArea) const
+    {
+        draw (g, clientArea,
+              AffineTransform::fromTargetPoints (clientArea.getX(),     clientArea.getY(),
+                                                 targetArea.getX(),     targetArea.getY(),
+                                                 clientArea.getRight(), clientArea.getY(),
+                                                 targetArea.getRight(), targetArea.getY(),
+                                                 clientArea.getRight(), clientArea.getBottom(),
+                                                 targetArea.getRight(), targetArea.getBottom()));
+    }
+
+    void draw (Graphics& g, Rectangle<float> clientArea, AffineTransform t) const
+    {
+        g.saveState();
+        g.addTransform (t);
+
+        for (const auto& p : paths)
+        {
+            if (p.path.getBounds().intersects (clientArea))
+            {
+                g.setFillType (p.fill);
+                g.fillPath (p.path);
+            }
+        }
+
+        g.restoreState();
+    }
+
+    const ClientArea* findClient (const String& clientName) const
+    {
+        for (const auto& c : clients)
+            if (c.name == clientName)
+                return &c;
+
+        return nullptr;
+    }
+
+    //==============================================================================
+    // Serialisation...
+
+    void save (OutputStream& out) const
+    {
+        out.writeInt (magic);
+        out.writeInt ((int) backgroundColour.getARGB());
+
+        out.writeInt (clients.size());
+
+        for (const auto& c : clients)
+        {
+            out.writeString (c.name);
+            writePoint (out, c.centre);
+            out.writeFloat (c.scaleFactor);
+        }
+
+        out.writeInt (paths.size());
+
+        for (const auto& p : paths)
+        {
+            writeFill (out, p.fill);
+            p.path.writePathToStream (out);
+        }
+    }
+
+    void load (InputStream& in)
+    {
+        if (in.readInt() != magic)
+            return;
+
+        backgroundColour = Colour ((uint32) in.readInt());
+
+        {
+            const int numClients = in.readInt();
+            clients.clearQuick();
+
+            for (int i = 0; i < numClients; ++i)
+            {
+                ClientArea c;
+                c.name = in.readString();
+                c.centre = readPoint (in);
+                c.scaleFactor = in.readFloat();
+                clients.add (c);
+            }
+        }
+
+        {
+            const int numPaths = in.readInt();
+            paths.clearQuick();
+
+            for (int i = 0; i < numPaths; ++i)
+            {
+                ColouredPath p;
+                p.fill = readFill (in);
+                p.path.loadPathFromStream (in);
+
+                paths.add (std::move (p));
+            }
+        }
+    }
+
+    MemoryBlock toMemoryBlock() const
+    {
+        MemoryOutputStream o;
+        save (o);
+        return o.getMemoryBlock();
+    }
+
+private:
+    //==============================================================================
+    static void writePoint (OutputStream& out, Point<float> p)
+    {
+        out.writeFloat (p.x);
+        out.writeFloat (p.y);
+    }
+
+    static void writeRect (OutputStream& out, Rectangle<float> r)
+    {
+        writePoint (out, r.getPosition());
+        out.writeFloat (r.getWidth());
+        out.writeFloat (r.getHeight());
+    }
+
+    static Point<float> readPoint (InputStream& in)
+    {
+        Point<float> p;
+        p.x = in.readFloat();
+        p.y = in.readFloat();
+        return p;
+    }
+
+    static Rectangle<float> readRect (InputStream& in)
+    {
+        Rectangle<float> r;
+        r.setPosition (readPoint (in));
+        r.setWidth (in.readFloat());
+        r.setHeight (in.readFloat());
+        return r;
+    }
+
+    static void writeFill (OutputStream& out, const FillType& f)
+    {
+        if (f.isColour())
+        {
+            out.writeByte (0);
+            out.writeInt ((int) f.colour.getARGB());
+        }
+        else if (f.isGradient())
+        {
+            const ColourGradient& cg = *f.gradient;
+            jassert (cg.getNumColours() >= 2);
+
+            out.writeByte (cg.isRadial ? 2 : 1);
+
+            writePoint (out, cg.point1);
+            writePoint (out, cg.point2);
+
+            out.writeCompressedInt (cg.getNumColours());
+
+            for (int i = 0; i < cg.getNumColours(); ++i)
+            {
+                out.writeDouble (cg.getColourPosition (i));
+                out.writeInt ((int) cg.getColour(i).getARGB());
+            }
+        }
+        else
+        {
+            jassertfalse;
+        }
+    }
+
+    static FillType readFill (InputStream& in)
+    {
+        int type = in.readByte();
+
+        if (type == 0)
+            return FillType (Colour ((uint32) in.readInt()));
+
+        if (type > 2)
+        {
+            jassertfalse;
+            return FillType();
+        }
+
+        ColourGradient cg;
+        cg.point1 = readPoint (in);
+        cg.point2 = readPoint (in);
+
+        cg.clearColours();
+
+        int numColours = in.readCompressedInt();
+
+        for (int i = 0; i < numColours; ++i)
+        {
+            const double pos = in.readDouble();
+            cg.addColour (pos, Colour ((uint32) in.readInt()));
+        }
+
+        jassert (cg.getNumColours() >= 2);
+
+        return FillType (cg);
+    }
+
+    const int magic = 0x2381239a;
+
+    JUCE_DECLARE_NON_COPYABLE (SharedCanvasDescription)
+};
+
+//==============================================================================
+class CanvasGeneratingContext    : public LowLevelGraphicsContext
+{
+public:
+    CanvasGeneratingContext (SharedCanvasDescription& c)  : canvas (c)
+    {
+        stateStack.add (new SavedState());
+    }
+
+    //==============================================================================
+    bool isVectorDevice() const override            { return true; }
+    float getPhysicalPixelScaleFactor() override    { return 1.0f; }
+    void setOrigin (Point<int> o) override          { addTransform (AffineTransform::translation ((float) o.x, (float) o.y)); }
+
+    void addTransform (const AffineTransform& t) override
+    {
+        getState().transform = t.followedBy (getState().transform);
+    }
+
+    bool clipToRectangle (const Rectangle<int>&) override                   { return true; }
+    bool clipToRectangleList (const RectangleList<int>&) override           { return true; }
+    void excludeClipRectangle (const Rectangle<int>&) override              {}
+    void clipToPath (const Path&, const AffineTransform&) override          {}
+    void clipToImageAlpha (const Image&, const AffineTransform&) override   {}
+
+    void saveState() override
+    {
+        stateStack.add (new SavedState (getState()));
+    }
+
+    void restoreState() override
+    {
+        jassert (stateStack.size() > 0);
+
+        if (stateStack.size() > 0)
+            stateStack.removeLast();
+    }
+
+    void beginTransparencyLayer (float alpha) override
+    {
+        saveState();
+        getState().transparencyLayer = new SharedCanvasHolder();
+        getState().transparencyOpacity = alpha;
+    }
+
+    void endTransparencyLayer() override
+    {
+        const ReferenceCountedObjectPtr<SharedCanvasHolder> finishedTransparencyLayer (getState().transparencyLayer);
+        float alpha = getState().transparencyOpacity;
+        restoreState();
+
+        if (SharedCanvasHolder* c = finishedTransparencyLayer)
+        {
+            for (auto& path : c->canvas.paths)
+            {
+                path.fill.setOpacity (path.fill.getOpacity() * alpha);
+                getTargetCanvas().paths.add (path);
+            }
+        }
+    }
+
+    Rectangle<int> getClipBounds() const override
+    {
+        return canvas.getLimits().getSmallestIntegerContainer()
+                .transformedBy (getState().transform.inverted());
+    }
+
+    bool clipRegionIntersects (const Rectangle<int>&) override      { return true; }
+    bool isClipEmpty() const override                               { return false; }
+
+    //==============================================================================
+    void setFill (const FillType& fillType) override                { getState().fillType = fillType; }
+    void setOpacity (float op) override                             { getState().fillType.setOpacity (op); }
+    void setInterpolationQuality (Graphics::ResamplingQuality) override {}
+
+    //==============================================================================
+    void fillRect (const Rectangle<int>& r, bool) override          { fillRect (r.toFloat()); }
+    void fillRectList (const RectangleList<float>& list) override   { fillPath (list.toPath(), AffineTransform()); }
+
+    void fillRect (const Rectangle<float>& r) override
+    {
+        Path p;
+        p.addRectangle (r.toFloat());
+        fillPath (p, AffineTransform());
+    }
+
+    void fillPath (const Path& p, const AffineTransform& t) override
+    {
+        Path p2 (p);
+        p2.applyTransform (t.followedBy (getState().transform));
+
+        getTargetCanvas().paths.add ({ std::move (p2), getState().fillType });
+    }
+
+    void drawImage (const Image&, const AffineTransform&) override {}
+
+    void drawLine (const Line<float>& line) override
+    {
+        Path p;
+        p.addLineSegment (line, 1.0f);
+        fillPath (p, AffineTransform());
+    }
+
+    //==============================================================================
+    const Font& getFont() override                  { return getState().font; }
+    void setFont (const Font& newFont) override     { getState().font = newFont; }
+
+    void drawGlyph (int glyphNumber, const AffineTransform& transform) override
+    {
+        Path p;
+        Font& font = getState().font;
+        font.getTypefacePtr()->getOutlineForGlyph (glyphNumber, p);
+        fillPath (p, AffineTransform::scale (font.getHeight() * font.getHorizontalScale(), font.getHeight()).followedBy (transform));
+    }
+
+private:
+    //==============================================================================
+    struct SharedCanvasHolder  : public ReferenceCountedObject
+    {
+        SharedCanvasDescription canvas;
+    };
+
+    struct SavedState
+    {
+        FillType fillType;
+        AffineTransform transform;
+        Font font;
+        ReferenceCountedObjectPtr<SharedCanvasHolder> transparencyLayer;
+        float transparencyOpacity = 1.0f;
+    };
+
+    SharedCanvasDescription& getTargetCanvas() const
+    {
+        if (SharedCanvasHolder* c = getState().transparencyLayer)
+            return c->canvas;
+
+        return canvas;
+    }
+
+    SavedState& getState() const noexcept
+    {
+        jassert (stateStack.size() > 0);
+        return *stateStack.getLast();
+    }
+
+    SharedCanvasDescription& canvas;
+    OwnedArray<SavedState> stateStack;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (CanvasGeneratingContext)
+};
+
+//==============================================================================
+/** Helper for breaking and reassembling a memory block into smaller checksummed
+    blocks that will fit inside UDP packets
+*/
+struct BlockPacketiser
+{
+    void createBlocksFromData (const MemoryBlock& data, size_t maxBlockSize)
+    {
+        jassert (blocks.size() == 0);
+
+        int offset = 0;
+        size_t remaining = data.getSize();
+
+        while (remaining > 0)
+        {
+            auto num = (size_t) jmin (maxBlockSize, remaining);
+            blocks.add (MemoryBlock (addBytesToPointer (data.getData(), offset), num));
+            offset += (int) num;
+            remaining -= num;
+        }
+
+        MemoryOutputStream checksumBlock;
+        checksumBlock << getLastPacketPrefix() << MD5 (data).toHexString() << (char) 0 << (char) 0;
+        blocks.add (checksumBlock.getMemoryBlock());
+
+        for (int i = 0; i < blocks.size(); ++i)
+        {
+            auto index = (uint32) ByteOrder::swapIfBigEndian (i);
+            blocks.getReference(i).append (&index, sizeof (index));
+        }
+    }
+
+    // returns true if this is an end-of-sequence block
+    bool appendIncomingBlock (MemoryBlock data)
+    {
+        if (data.getSize() > 4)
+            blocks.addSorted (*this, data);
+
+        return String (CharPointer_ASCII ((const char*) data.getData())).startsWith (getLastPacketPrefix());
+    }
+
+    bool reassemble (MemoryBlock& result)
+    {
+        result.reset();
+
+        if (blocks.size() > 1)
+        {
+            for (int i = 0; i < blocks.size() - 1; ++i)
+                result.append (blocks.getReference(i).getData(), blocks.getReference(i).getSize() - 4);
+
+            String storedMD5 (String (CharPointer_ASCII ((const char*) blocks.getLast().getData()))
+                                .fromFirstOccurrenceOf (getLastPacketPrefix(), false, false));
+
+            blocks.clearQuick();
+
+            if (MD5 (result).toHexString().trim().equalsIgnoreCase (storedMD5.trim()))
+                return true;
+        }
+
+        result.reset();
+        return false;
+    }
+
+    static int compareElements (const MemoryBlock& b1, const MemoryBlock& b2)
+    {
+        auto i1 = ByteOrder::littleEndianInt (addBytesToPointer (b1.getData(), b1.getSize() - 4));
+        auto i2 = ByteOrder::littleEndianInt (addBytesToPointer (b2.getData(), b2.getSize() - 4));
+        return (int) (i1 - i2);
+    }
+
+    static const char* getLastPacketPrefix()   { return "**END_OF_PACKET_LIST** "; }
+
+    Array<MemoryBlock> blocks;
+};
+
+
+//==============================================================================
+struct AnimatedContent
+{
+    virtual ~AnimatedContent() {}
+
+    virtual String getName() const = 0;
+    virtual void reset() = 0;
+    virtual void generateCanvas (Graphics&, SharedCanvasDescription& canvas, Rectangle<float> activeArea) = 0;
+    virtual void handleTouch (Point<float> position) = 0;
+};

deps/juce/extras/NetworkGraphicsDemo/Source/SlaveComponent.h

@@ -0,0 +1,224 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2020 - Raw Material Software Limited
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 6 End-User License
+   Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
+
+   End User License Agreement: www.juce.com/juce-6-licence
+   Privacy Policy: www.juce.com/juce-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
+   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
+   DISCLAIMED.
+
+  ==============================================================================
+*/
+
+
+/**
+    This component runs in a slave process, draws the part of the canvas that this
+    particular client covers, and updates itself when messages arrive from the master
+    containing new canvas states.
+*/
+class SlaveCanvasComponent  : public Component,
+                              private OSCSender,
+                              private OSCReceiver,
+                              private OSCReceiver::Listener<OSCReceiver::RealtimeCallback>,
+                              private AsyncUpdater,
+                              private Timer
+{
+public:
+    SlaveCanvasComponent (PropertiesFile& p, int windowIndex)  : properties (p)
+    {
+        {
+            String uuidPropName ("UUID" + String (windowIndex));
+            clientName = properties.getValue (uuidPropName);
+
+            if (clientName.isEmpty())
+            {
+                clientName = "CLIENT_" + String (Random().nextInt (10000)).toUpperCase();
+                properties.setValue (uuidPropName, clientName);
+            }
+        }
+
+        setOpaque (true);
+        setSize (1500, 900);
+
+        if (! OSCSender::connect (getBroadcastIPAddress(), clientPortNumber))
+            error = "Client app OSC sender: network connection error.";
+
+        if (! OSCReceiver::connect (masterPortNumber))
+            error = "Client app OSC receiver: network connection error.";
+
+        OSCReceiver::addListener (this);
+
+        timerCallback();
+        startTimer (2000);
+    }
+
+    ~SlaveCanvasComponent() override
+    {
+        OSCReceiver::removeListener (this);
+    }
+
+private:
+    void mouseDrag (const MouseEvent& e) override
+    {
+        auto clientArea = getAreaInGlobalSpace();
+
+        if (! clientArea.isEmpty())
+        {
+            OSCMessage message (userInputOSCAddress);
+
+            message.addString (clientName);
+            message.addFloat32 (e.position.x * clientArea.getWidth()  / (float) getWidth()  + clientArea.getX());
+            message.addFloat32 (e.position.y * clientArea.getHeight() / (float) getHeight() + clientArea.getY());
+
+            send (message);
+        }
+    }
+
+    //==============================================================================
+    void oscMessageReceived (const OSCMessage& message) override
+    {
+        auto address = message.getAddressPattern();
+
+        if (address.matches (canvasStateOSCAddress))
+            canvasStateOSCMessageReceived (message);
+    }
+
+    struct NewStateMessage  : public Message
+    {
+        NewStateMessage (const MemoryBlock& d) : data (d) {}
+        MemoryBlock data;
+    };
+
+    void canvasStateOSCMessageReceived (const OSCMessage& message)
+    {
+        if (message.isEmpty() || ! message[0].isBlob())
+            return;
+
+        if (packetiser.appendIncomingBlock (message[0].getBlob()))
+        {
+            const ScopedLock sl (canvasLock);
+
+            MemoryBlock newCanvasData;
+
+            if (packetiser.reassemble (newCanvasData))
+            {
+                MemoryInputStream i (newCanvasData.getData(), newCanvasData.getSize(), false);
+                canvas2.load (i);
+                triggerAsyncUpdate();
+            }
+        }
+    }
+
+    //==============================================================================
+    String getMachineInfoToDisplay() const
+    {
+        auto* display = Desktop::getInstance().getDisplays().getDisplayForPoint (getScreenBounds().getCentre());
+        return getOSName() + "   " + String (display->dpi) + "   "  + String (display->scale);
+    }
+
+    static String getOSName()
+    {
+       #if JUCE_MAC
+        return "Mac OSX";
+       #elif JUCE_ANDROID
+        return "Android";
+       #elif JUCE_IOS
+        return "iOS";
+       #elif JUCE_WINDOWS
+        return "Windows";
+       #elif JUCE_LINUX
+        return "Linux";
+       #elif JUCE_BSD
+        return "BSD";
+       #endif
+    }
+
+    void paint (Graphics& g) override
+    {
+        g.fillAll (canvas.backgroundColour);
+
+        auto clientArea = getAreaInGlobalSpace();
+
+        if (clientArea.isEmpty())
+        {
+            g.setColour (Colours::red.withAlpha (0.5f));
+            g.setFont (20.0f);
+            g.drawText ("Not Connected", getLocalBounds(), Justification::centred, false);
+            return;
+        }
+
+        canvas.draw (g, getLocalBounds().toFloat(), clientArea);
+
+        g.setFont (Font (34.0f));
+        g.setColour (Colours::white.withAlpha (0.6f));
+
+        g.drawText (getMachineInfoToDisplay(),
+                    getLocalBounds().reduced (10).removeFromBottom (20),
+                    Justification::centredRight, true);
+
+        if (error.isNotEmpty())
+        {
+            g.setColour (Colours::red);
+            g.drawText (error, getLocalBounds().reduced (10).removeFromBottom (80),
+                        Justification::centredRight, true);
+        }
+    }
+
+    Rectangle<float> getAreaInGlobalSpace() const
+    {
+        if (auto client = canvas.findClient (clientName))
+        {
+            auto screenBounds = getScreenBounds();
+            auto* display = Desktop::getInstance().getDisplays().getDisplayForPoint (screenBounds.getCentre());
+            return ((screenBounds - display->userArea.getCentre()).toFloat() / (client->scaleFactor * display->dpi / display->scale)) + client->centre;
+        }
+
+        return {};
+    }
+
+    Rectangle<float> getScreenAreaInGlobalSpace() const
+    {
+        if (auto client = canvas.findClient (clientName))
+        {
+            auto* display = Desktop::getInstance().getDisplays().getDisplayForPoint (getScreenBounds().getCentre());
+            return (display->userArea.toFloat() / (client->scaleFactor * display->dpi / display->scale)).withCentre (client->centre);
+        }
+
+        return {};
+    }
+
+    void timerCallback() override
+    {
+        send (newClientOSCAddress, clientName + ":" + IPAddress::getLocalAddress().toString()
+                                              + ":" + getScreenAreaInGlobalSpace().toString());
+    }
+
+    void handleAsyncUpdate() override
+    {
+        const ScopedLock sl (canvasLock);
+        canvas.swapWith (canvas2);
+        repaint();
+    }
+
+    SharedCanvasDescription canvas, canvas2;
+    PropertiesFile& properties;
+    String clientName, error;
+
+    CriticalSection canvasLock;
+    BlockPacketiser packetiser;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SlaveCanvasComponent)
+};