Added Sound Stage example.

examples/CMakeLists.txt

@@ -40,4 +40,8 @@ if(SFML_BUILD_GRAPHICS)
 endif()
 if(SFML_BUILD_GRAPHICS AND SFML_BUILD_AUDIO)
     add_subdirectory(tennis)
+
+    if(NOT SFML_OS_IOS)
+        add_subdirectory(sound_stage)
+    endif()
 endif()

examples/sound_stage/CMakeLists.txt

@@ -0,0 +1,11 @@
+# all source files
+set(SRC SoundStage.cpp imgui-SFML.cpp imgui.cpp imgui_widgets.cpp imgui_draw.cpp imgui_tables.cpp imgui_stdlib.cpp)
+
+# define the sound-stage target
+sfml_add_example(sound-stage GUI_APP
+                 SOURCES ${SRC}
+                 DEPENDS SFML::Audio SFML::Graphics
+                 RESOURCES_DIR resources)
+
+# external dependency headers
+target_include_directories(sound-stage SYSTEM PRIVATE ${PROJECT_SOURCE_DIR}/examples/sound_stage)

examples/sound_stage/SoundStage.cpp

@@ -0,0 +1,608 @@
+
+////////////////////////////////////////////////////////////
+// Headers
+////////////////////////////////////////////////////////////
+#include <SFML/Audio/Listener.hpp>
+#include <SFML/Audio/Music.hpp>
+#include <SFML/Audio/Sound.hpp>
+#include <SFML/Audio/SoundBuffer.hpp>
+#include <SFML/Graphics/CircleShape.hpp>
+#include <SFML/Graphics/RectangleShape.hpp>
+#include <SFML/Graphics/Font.hpp>
+#include <SFML/Graphics/RenderWindow.hpp>
+#include <SFML/Graphics/Text.hpp>
+#include <SFML/System/Clock.hpp>
+#include <SFML/Window/Event.hpp>
+#include <SFML/Window/VideoMode.hpp>
+
+#include "imgui-SFML.h"
+#include "imgui.h"
+#include "imgui_stdlib.h"
+
+#include <cmath>
+#include <limits>
+#include <memory>
+#include <random>
+#include <vector>
+
+namespace
+{
+constexpr auto windowWidth  = 1600u;
+constexpr auto windowHeight = 900u;
+constexpr auto markerRadius = 40.f;
+constexpr auto pi           = 3.14159265359;
+
+std::filesystem::path resourcesDir()
+{
+#ifdef SFML_SYSTEM_IOS
+    return "";
+#else
+    return "resources";
+#endif
+}
+
+void errorMessage(const std::string& message)
+{
+    if (ImGui::BeginPopupModal("Error"))
+    {
+        ImGui::Text(message.c_str());
+        ImGui::EndPopup();
+    }
+}
+
+struct Marker
+{
+    Marker(const sf::SoundSource* theSoundSource,
+           const sf::Vector2f*    theListenerPosition,
+           const sf::Font&        font,
+           const sf::Color&       color,
+           const sf::String&      text) :
+    soundSource(theSoundSource),
+    listenerPosition(theListenerPosition),
+    coneCenter({120.f, 1.f}),
+    coneInner({100.f, 1.f}),
+    coneOuter({100.f, 1.f}),
+    marker(markerRadius),
+    label(font, text, static_cast<unsigned int>(markerRadius))
+    {
+        coneCenter.setFillColor(sf::Color::Magenta);
+        coneInner.setFillColor(sf::Color(255, 0, 127));
+        coneOuter.setFillColor(sf::Color::Red);
+        marker.setFillColor(color);
+        label.setFillColor(sf::Color::Black);
+        label.setStyle(sf::Text::Bold);
+    }
+
+    void draw(sf::RenderTarget& target)
+    {
+        auto listenerOffset = (listenerPosition && soundSource && soundSource->isRelativeToListener())
+                                  ? *listenerPosition
+                                  : sf::Vector2f();
+        auto labelBounds    = label.getLocalBounds().getSize();
+        labelBounds.x *= 0.5f;
+        labelBounds.y *= 0.75f;
+
+        target.draw(coneCenter);
+
+        sf::Angle innerAngle;
+        sf::Angle outerAngle;
+
+        // Check if we are a SoundSource or the Listener
+        if (soundSource)
+        {
+            innerAngle = soundSource->getCone().innerAngle;
+            outerAngle = soundSource->getCone().outerAngle;
+        }
+        else
+        {
+            innerAngle = sf::Listener::getCone().innerAngle;
+            outerAngle = sf::Listener::getCone().outerAngle;
+        }
+
+        if (innerAngle != sf::degrees(360))
+        {
+            coneInner.setRotation(coneCenter.getRotation() - innerAngle / 2);
+            target.draw(coneInner);
+            coneInner.setRotation(coneCenter.getRotation() + innerAngle / 2);
+            target.draw(coneInner);
+        }
+
+        if (outerAngle != sf::degrees(360))
+        {
+            coneOuter.setRotation(coneCenter.getRotation() - outerAngle / 2);
+            target.draw(coneOuter);
+            coneOuter.setRotation(coneCenter.getRotation() + outerAngle / 2);
+            target.draw(coneOuter);
+        }
+
+        target.draw(marker, sf::Transform().translate(-sf::Vector2f(markerRadius, markerRadius) + listenerOffset));
+        target.draw(label, sf::Transform().translate(-labelBounds + listenerOffset));
+    }
+
+    const sf::Vector2f& getPosition() const
+    {
+        return marker.getPosition();
+    }
+
+    void setPosition(const sf::Vector2f& position)
+    {
+        coneCenter.setPosition(position);
+        coneInner.setPosition(position);
+        coneOuter.setPosition(position);
+        marker.setPosition(position);
+        label.setPosition(position);
+    }
+
+    sf::Angle getRotation() const
+    {
+        return coneCenter.getRotation();
+    }
+
+    void setRotation(const sf::Angle& angle)
+    {
+        coneCenter.setRotation(angle);
+    }
+
+    const sf::SoundSource* soundSource;
+    const sf::Vector2f*    listenerPosition;
+    sf::RectangleShape     coneCenter;
+    sf::RectangleShape     coneInner;
+    sf::RectangleShape     coneOuter;
+    sf::CircleShape        marker;
+    sf::Text               label;
+};
+
+struct Object
+{
+    Object(const sf::Font&     font,
+           sf::SoundSource&    theSoundSource,
+           const sf::Vector2f& listenerPosition,
+           const sf::Color&    markerColor,
+           const std::string&  markerPrefix) :
+    index(
+        []()
+        {
+            static std::size_t nextIndex{};
+            return nextIndex++;
+        }()),
+    soundSource(theSoundSource),
+    marker(&soundSource, &listenerPosition, font, markerColor, markerPrefix + std::to_string(index))
+    {
+        position = []()
+        {
+            static std::random_device                    rd;
+            static std::mt19937                          rng(rd());
+            static std::uniform_real_distribution<float> xDistribution(-100.f, 100.f);
+            static std::uniform_real_distribution<float> yDistribution(-100.f, 100.f);
+            return sf::Vector2f(xDistribution(rng), yDistribution(rng));
+        }();
+        rotation = sf::degrees(270);
+        marker.setPosition(position);
+        marker.setRotation(rotation);
+    }
+
+    virtual ~Object() = default;
+
+    virtual void draw(sf::RenderTarget& target) = 0;
+
+    void drawMarker(sf::RenderTarget& target)
+    {
+        marker.draw(target);
+    }
+
+    void drawPositionRotationControls()
+    {
+        ImGui::DragFloat2("Position", &position.x);
+
+        if (auto radians = rotation.asRadians();
+            ImGui::DragFloat("Rotation", &radians, 0.01f, static_cast<float>(-2 * pi), static_cast<float>(2 * pi)))
+            rotation = sf::radians(radians);
+    }
+
+    void drawConeControls()
+    {
+        auto cone = soundSource.getCone();
+
+        if (auto innerAngle = cone.innerAngle.asRadians();
+            ImGui::DragFloat("Cone Inner", &innerAngle, 0.01f, 0.f, static_cast<float>(2 * pi)))
+            cone.innerAngle = std::clamp(sf::radians(innerAngle), sf::degrees(0), cone.outerAngle);
+
+        if (auto outerAngle = cone.outerAngle.asRadians();
+            ImGui::DragFloat("Cone Outer", &outerAngle, 0.01f, 0.f, static_cast<float>(2 * pi)))
+            cone.outerAngle = std::clamp(sf::radians(outerAngle), cone.innerAngle, sf::degrees(360));
+
+        if (auto outerGain = cone.outerGain; ImGui::DragFloat("Outer Gain", &outerGain, 0.001f, 0.f, 1.f))
+            cone.outerGain = outerGain;
+
+        soundSource.setCone(cone);
+    }
+
+    void drawSoundSourceControls()
+    {
+        if (auto relative = soundSource.isRelativeToListener(); ImGui::Checkbox("Relative to Listener", &relative))
+            soundSource.setRelativeToListener(relative);
+
+        if (auto pitch = soundSource.getPitch(); ImGui::DragFloat("Pitch", &pitch, 0.01f, 0.f, 10.f))
+            soundSource.setPitch(pitch);
+
+        if (auto volume = soundSource.getVolume(); ImGui::DragFloat("Volume", &volume, 1.f, 0.f, 100.f))
+            soundSource.setVolume(volume);
+
+        if (auto attenuation = soundSource.getAttenuation();
+            ImGui::DragFloat("Attenuation", &attenuation, 0.01f, 0.f, 10.f))
+            soundSource.setAttenuation(attenuation);
+
+        if (auto minDistance = soundSource.getMinDistance(); ImGui::DragFloat("Min. Distance", &minDistance))
+            soundSource.setMinDistance(minDistance);
+    }
+
+    void drawPlayControls()
+    {
+        if (ImGui::Button("Play"))
+            soundSource.play();
+        ImGui::SameLine();
+        if (ImGui::Button("Pause"))
+            soundSource.pause();
+        ImGui::SameLine();
+        if (ImGui::Button("Stop"))
+            soundSource.stop();
+    }
+
+    void update(sf::Time /*tick*/)
+    {
+        marker.setPosition(position);
+        marker.setRotation(rotation);
+        soundSource.setPosition({position.x, 0, position.y});
+        soundSource.setDirection({std::cos(rotation.asRadians()), 0, std::sin(rotation.asRadians())});
+    }
+
+    std::size_t      index;
+    sf::SoundSource& soundSource;
+    Marker           marker;
+    sf::Vector2f     position;
+    sf::Angle        rotation;
+    sf::Vector2f     amplitude;
+    sf::Vector2f     frequency;
+    float            time = 0.f;
+};
+
+struct Sound : Object
+{
+    Sound(const sf::Font& font, const sf::Vector2f& listenerPosition) :
+    Object(font, sound, listenerPosition, sf::Color::Yellow, "S"),
+    sound(buffer)
+    {
+        sound.setAttenuation(0.01f);
+    }
+
+    void draw(sf::RenderTarget& target) override
+    {
+        if (sound.getBuffer() && sound.getBuffer()->getDuration() != sf::Time::Zero)
+            drawMarker(target);
+
+        ImGui::SetNextWindowSize({0.f, 0.f});
+        ImGui::Begin(("Sound " + std::to_string(index)).c_str());
+
+        ImGui::InputText("File Path", &path);
+        ImGui::SameLine();
+        if (ImGui::Button("Load"))
+        {
+            sound.stop();
+
+            if (!buffer.loadFromFile(path))
+                errorMessage("Failed to load " + path);
+        }
+
+        if (sound.getBuffer() && sound.getBuffer()->getDuration() != sf::Time::Zero)
+        {
+            auto duration = sound.getBuffer() ? sound.getBuffer()->getDuration().asSeconds() : 0.f;
+            if (auto offset = sound.getPlayingOffset().asSeconds();
+                ImGui::SliderFloat("Playing Offset", &offset, 0.f, duration))
+                sound.setPlayingOffset(sf::seconds(offset));
+
+            drawPositionRotationControls();
+            drawConeControls();
+            drawSoundSourceControls();
+
+            if (auto loop = sound.getLoop(); ImGui::Checkbox("Loop", &loop))
+                sound.setLoop(loop);
+
+            drawPlayControls();
+        }
+
+        ImGui::End();
+    }
+
+    std::string     path = (resourcesDir() / "ding.flac").string();
+    sf::SoundBuffer buffer;
+    sf::Sound       sound;
+};
+
+
+struct Music : Object
+{
+    Music(const sf::Font& font, const sf::Vector2f& listenerPosition) :
+    Object(font, music, listenerPosition, sf::Color::Cyan, "M")
+    {
+        music.setAttenuation(0.01f);
+    }
+
+    void draw(sf::RenderTarget& target) override
+    {
+        if (music.getDuration() != sf::Time::Zero)
+            drawMarker(target);
+
+        ImGui::SetNextWindowSize({0.f, 0.f});
+        ImGui::Begin(("Music " + std::to_string(index)).c_str());
+
+        ImGui::InputText("File Path", &path);
+        ImGui::SameLine();
+        if (ImGui::Button("Load"))
+        {
+            music.stop();
+
+            if (!music.openFromFile(path))
+                errorMessage("Failed to load " + path);
+        }
+
+        if (music.getDuration() != sf::Time::Zero)
+        {
+            if (auto offset = music.getPlayingOffset().asSeconds();
+                ImGui::SliderFloat("Playing Offset", &offset, 0.f, music.getDuration().asSeconds()))
+                music.setPlayingOffset(sf::seconds(offset));
+
+            drawPositionRotationControls();
+            drawConeControls();
+            drawSoundSourceControls();
+
+            if (auto loop = music.getLoop(); ImGui::Checkbox("Loop", &loop))
+                music.setLoop(loop);
+
+            drawPlayControls();
+        }
+
+        ImGui::End();
+    }
+
+    std::string path  = (resourcesDir() / "doodle_pop.ogg").string();
+    sf::Music   music;
+};
+
+
+struct Tone : sf::SoundStream, Object
+{
+    Tone(const sf::Font& font, const sf::Vector2f& listenerPosition) :
+    Object(font, *this, listenerPosition, sf::Color::Green, "T"),
+    sampleBuffer(chunkSize, 0)
+    {
+        initialize(1, sampleRate, {sf::SoundChannel::Mono});
+
+        setAttenuation(0.01f);
+    }
+
+    void draw(sf::RenderTarget& target) override
+    {
+        drawMarker(target);
+
+        ImGui::SetNextWindowSize({0.f, 0.f});
+        ImGui::Begin(("Tone " + std::to_string(index)).c_str());
+
+        if (ImGui::RadioButton("Sine", type == Type::Sine))
+            type = Type::Sine;
+        ImGui::SameLine();
+        if (ImGui::RadioButton("Square", type == Type::Square))
+            type = Type::Square;
+        ImGui::SameLine();
+        if (ImGui::RadioButton("Triangle", type == Type::Triangle))
+            type = Type::Triangle;
+        ImGui::SameLine();
+        if (ImGui::RadioButton("Sawtooth", type == Type::Sawtooth))
+            type = Type::Sawtooth;
+
+        ImGui::DragFloat("Amplitude", &amplitude, 0.01f, 0.f, 1.f);
+        ImGui::DragFloat("Frequency", &frequency, 1.f, 0.f, 1000.f);
+
+        ImGui::PlotLines("Wave",
+                         [](void* data, int sampleIndex)
+                         {
+                             const auto& samples = *static_cast<std::vector<std::int16_t>*>(data);
+                             return static_cast<float>(samples[sampleIndex]);
+                         },
+                         &sampleBuffer,
+                         static_cast<int>(sampleBuffer.size()),
+                         0,
+                         nullptr,
+                         std::numeric_limits<std::int16_t>::min() * amplitude,
+                         std::numeric_limits<std::int16_t>::max() * amplitude,
+                         {0.f, 100.f});
+
+        drawPositionRotationControls();
+        drawConeControls();
+        drawSoundSourceControls();
+        drawPlayControls();
+
+        ImGui::End();
+    }
+
+    bool onGetData(sf::SoundStream::Chunk& chunk) override
+    {
+        const auto            period = 1.0 / frequency;
+
+        for (auto i = 0u; i < chunkSize; ++i)
+        {
+            auto value = 0.0;
+
+            switch (type)
+            {
+                case Type::Sine:
+                {
+                    value = amplitude * std::sin(2 * pi * frequency * time);
+                    break;
+                }
+                case Type::Square:
+                {
+                    value = amplitude *
+                            (2 * (2 * std::floor(frequency * time) - std::floor(2 * frequency * time)) + 1);
+                    break;
+                }
+                case Type::Triangle:
+                {
+                    value = 4 * amplitude / period *
+                                std::abs(std::fmod(((std::fmod((time - period / 4), period)) + period), period) -
+                                         period / 2) -
+                            amplitude;
+                    break;
+                }
+                case Type::Sawtooth:
+                {
+                    value = amplitude * 2 * (time / period - std::floor(0.5 + time / period));
+                    break;
+                }
+            }
+
+            sampleBuffer[i]  = static_cast<std::int16_t>(std::lround(value * std::numeric_limits<std::int16_t>::max()));
+            time += timePerSample;
+        }
+
+        chunk.sampleCount = chunkSize;
+        chunk.samples     = sampleBuffer.data();
+
+        return true;
+    }
+
+    void onSeek(sf::Time) override
+    {
+        // It doesn't make sense to seek in a tone generator
+    }
+
+    enum class Type
+    {
+        Sine,
+        Square,
+        Triangle,
+        Sawtooth
+    };
+
+    static constexpr unsigned int sampleRate = 44100;
+    static constexpr std::size_t  chunkSize  = sampleRate / 100;
+    std::vector<std::int16_t>     sampleBuffer;
+    Type                          type          = Type::Triangle;
+    float                         amplitude     = 0.05f;
+    float                         frequency     = 220.f;
+    double                        time          = 0.f;
+    double                        timePerSample = 1.f / static_cast<double>(sampleRate);
+};
+}
+
+
+////////////////////////////////////////////////////////////
+/// Entry point of application
+///
+/// \return Application exit code
+///
+////////////////////////////////////////////////////////////
+int main()
+{
+    sf::RenderWindow window(sf::VideoMode({windowWidth, windowHeight}), "SFML Sound Stage");
+    window.setFramerateLimit(60);
+    window.setView(sf::View(sf::Vector2f(0, 0), static_cast<sf::Vector2f>(window.getSize())));
+
+    ImGui::SFML::Init(window);
+
+    sf::Font font;
+    if (!font.loadFromFile(resourcesDir() / "tuffy.ttf"))
+        return EXIT_FAILURE;
+
+    sf::Vector2f listenerPosition;
+
+    Marker marker(nullptr, nullptr, font, sf::Color::White, "L");
+    marker.setRotation(sf::degrees(270));
+
+    std::vector<std::unique_ptr<Object>> objects;
+
+    sf::Clock deltaClock;
+    while (window.isOpen())
+    {
+        sf::Event event;
+        while (window.pollEvent(event))
+        {
+            ImGui::SFML::ProcessEvent(window, event);
+
+            switch (event.type)
+            {
+                case sf::Event::Resized:
+                    window.setView(sf::View(sf::Vector2f(0, 0), static_cast<sf::Vector2f>(window.getSize())));
+                    break;
+                case sf::Event::Closed:
+                    window.close();
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        const auto tick = deltaClock.restart();
+
+        for (auto& object : objects)
+            object->update(tick);
+
+        ImGui::SFML::Update(window, tick);
+
+        ImGui::SetNextWindowSize({0.f, 0.f});
+        ImGui::Begin("Control");
+
+        if (ImGui::DragFloat2("Listener Position", &listenerPosition.x))
+        {
+            marker.setPosition(listenerPosition);
+            sf::Listener::setPosition({listenerPosition.x, 0, listenerPosition.y});
+        }
+
+        if (auto rotation = marker.getRotation().asRadians();
+            ImGui::DragFloat("Listener Rotation", &rotation, 0.01f, static_cast<float>(-2 * pi), static_cast<float>(2 * pi)))
+        {
+            marker.setRotation(sf::radians(rotation));
+            sf::Listener::setDirection({std::cos(rotation), 0, std::sin(rotation)});
+        }
+
+        auto cone = sf::Listener::getCone();
+
+        if (auto innerAngle = cone.innerAngle.asRadians();
+            ImGui::DragFloat("Listener Cone Inner", &innerAngle, 0.01f, 0.f, static_cast<float>(2 * pi)))
+            cone.innerAngle = std::clamp(sf::radians(innerAngle), sf::degrees(0), cone.outerAngle);
+
+        if (auto outerAngle = cone.outerAngle.asRadians();
+            ImGui::DragFloat("Listener Cone Outer", &outerAngle, 0.01f, 0.f, static_cast<float>(2 * pi)))
+            cone.outerAngle = std::clamp(sf::radians(outerAngle), cone.innerAngle, sf::degrees(360));
+
+        if (auto outerGain = cone.outerGain; ImGui::DragFloat("Outer Gain", &outerGain, 0.001f, 0.f, 1.f))
+            cone.outerGain = outerGain;
+
+        sf::Listener::setCone(cone);
+
+        if (ImGui::Button("Add Sound"))
+            objects.emplace_back(std::make_unique<Sound>(font, listenerPosition));
+        ImGui::SameLine();
+        if (ImGui::Button("Add Music"))
+            objects.emplace_back(std::make_unique<Music>(font, listenerPosition));
+        ImGui::SameLine();
+        if (ImGui::Button("Add Tone"))
+            objects.emplace_back(std::make_unique<Tone>(font, listenerPosition));
+
+        ImGui::End();
+
+        window.clear();
+
+        for (auto& object : objects)
+            object->draw(window);
+
+        marker.draw(window);
+
+        ImGui::SFML::Render(window);
+
+        window.display();
+    }
+
+    ImGui::SFML::Shutdown();
+
+    return 0;
+}

examples/sound_stage/imconfig-SFML.h

@@ -0,0 +1,29 @@
+// Add this to your imconfig.h
+
+#include <SFML/Graphics/Color.hpp>
+#include <SFML/System/Vector2.hpp>
+
+#include <cstdint>
+
+#include "imgui-SFML_export.h"
+
+#define IM_VEC2_CLASS_EXTRA           \
+    template<typename T>              \
+    ImVec2(const sf::Vector2<T>& v) { \
+        x = static_cast<float>(v.x);  \
+        y = static_cast<float>(v.y);  \
+    }                                 \
+                                      \
+    template<typename T>              \
+    operator sf::Vector2<T>() const { \
+        return sf::Vector2<T>(x, y);  \
+    }
+
+#define IM_VEC4_CLASS_EXTRA                                                                        \
+    ImVec4(const sf::Color& c) : x(c.r / 255.f), y(c.g / 255.f), z(c.b / 255.f), w(c.a / 255.f) {} \
+    operator sf::Color() const {                                                                   \
+        return sf::Color(static_cast<std::uint8_t>(x * 255.f),                                     \
+                         static_cast<std::uint8_t>(y * 255.f),                                     \
+                         static_cast<std::uint8_t>(z * 255.f),                                     \
+                         static_cast<std::uint8_t>(w * 255.f));                                    \
+    }

examples/sound_stage/imconfig.h

@@ -0,0 +1,124 @@
+//-----------------------------------------------------------------------------
+// COMPILE-TIME OPTIONS FOR DEAR IMGUI
+// Runtime options (clipboard callbacks, enabling various features, etc.) can generally be set via the ImGuiIO structure.
+// You can use ImGui::SetAllocatorFunctions() before calling ImGui::CreateContext() to rewire memory allocation functions.
+//-----------------------------------------------------------------------------
+// A) You may edit imconfig.h (and not overwrite it when updating Dear ImGui, or maintain a patch/rebased branch with your modifications to it)
+// B) or '#define IMGUI_USER_CONFIG "my_imgui_config.h"' in your project and then add directives in your own file without touching this template.
+//-----------------------------------------------------------------------------
+// You need to make sure that configuration settings are defined consistently _everywhere_ Dear ImGui is used, which include the imgui*.cpp
+// files but also _any_ of your code that uses Dear ImGui. This is because some compile-time options have an affect on data structures.
+// Defining those options in imconfig.h will ensure every compilation unit gets to see the same data structure layouts.
+// Call IMGUI_CHECKVERSION() from your .cpp files to verify that the data structures your files are using are matching the ones imgui.cpp is using.
+//-----------------------------------------------------------------------------
+
+#pragma once
+
+//---- Define assertion handler. Defaults to calling assert().
+// If your macro uses multiple statements, make sure is enclosed in a 'do { .. } while (0)' block so it can be used as a single statement.
+//#define IM_ASSERT(_EXPR)  MyAssert(_EXPR)
+//#define IM_ASSERT(_EXPR)  ((void)(_EXPR))     // Disable asserts
+
+//---- Define attributes of all API symbols declarations, e.g. for DLL under Windows
+// Using Dear ImGui via a shared library is not recommended, because of function call overhead and because we don't guarantee backward nor forward ABI compatibility.
+// DLL users: heaps and globals are not shared across DLL boundaries! You will need to call SetCurrentContext() + SetAllocatorFunctions()
+// for each static/DLL boundary you are calling from. Read "Context and Memory Allocators" section of imgui.cpp for more details.
+//#define IMGUI_API __declspec( dllexport )
+//#define IMGUI_API __declspec( dllimport )
+
+//---- Don't define obsolete functions/enums/behaviors. Consider enabling from time to time after updating to avoid using soon-to-be obsolete function/names.
+//#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+//#define IMGUI_DISABLE_OBSOLETE_KEYIO                      // 1.87: disable legacy io.KeyMap[]+io.KeysDown[] in favor io.AddKeyEvent(). This will be folded into IMGUI_DISABLE_OBSOLETE_FUNCTIONS in a few versions.
+
+//---- Disable all of Dear ImGui or don't implement standard windows/tools.
+// It is very strongly recommended to NOT disable the demo windows and debug tool during development. They are extremely useful in day to day work. Please read comments in imgui_demo.cpp.
+//#define IMGUI_DISABLE                                     // Disable everything: all headers and source files will be empty.
+//#define IMGUI_DISABLE_DEMO_WINDOWS                        // Disable demo windows: ShowDemoWindow()/ShowStyleEditor() will be empty.
+//#define IMGUI_DISABLE_DEBUG_TOOLS                         // Disable metrics/debugger and other debug tools: ShowMetricsWindow(), ShowDebugLogWindow() and ShowStackToolWindow() will be empty (this was called IMGUI_DISABLE_METRICS_WINDOW before 1.88).
+
+//---- Don't implement some functions to reduce linkage requirements.
+//#define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS   // [Win32] Don't implement default clipboard handler. Won't use and link with OpenClipboard/GetClipboardData/CloseClipboard etc. (user32.lib/.a, kernel32.lib/.a)
+//#define IMGUI_ENABLE_WIN32_DEFAULT_IME_FUNCTIONS          // [Win32] [Default with Visual Studio] Implement default IME handler (require imm32.lib/.a, auto-link for Visual Studio, -limm32 on command-line for MinGW)
+//#define IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS         // [Win32] [Default with non-Visual Studio compilers] Don't implement default IME handler (won't require imm32.lib/.a)
+//#define IMGUI_DISABLE_WIN32_FUNCTIONS                     // [Win32] Won't use and link with any Win32 function (clipboard, ime).
+//#define IMGUI_ENABLE_OSX_DEFAULT_CLIPBOARD_FUNCTIONS      // [OSX] Implement default OSX clipboard handler (need to link with '-framework ApplicationServices', this is why this is not the default).
+//#define IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS            // Don't implement ImFormatString/ImFormatStringV so you can implement them yourself (e.g. if you don't want to link with vsnprintf)
+//#define IMGUI_DISABLE_DEFAULT_MATH_FUNCTIONS              // Don't implement ImFabs/ImSqrt/ImPow/ImFmod/ImCos/ImSin/ImAcos/ImAtan2 so you can implement them yourself.
+//#define IMGUI_DISABLE_FILE_FUNCTIONS                      // Don't implement ImFileOpen/ImFileClose/ImFileRead/ImFileWrite and ImFileHandle at all (replace them with dummies)
+//#define IMGUI_DISABLE_DEFAULT_FILE_FUNCTIONS              // Don't implement ImFileOpen/ImFileClose/ImFileRead/ImFileWrite and ImFileHandle so you can implement them yourself if you don't want to link with fopen/fclose/fread/fwrite. This will also disable the LogToTTY() function.
+//#define IMGUI_DISABLE_DEFAULT_ALLOCATORS                  // Don't implement default allocators calling malloc()/free() to avoid linking with them. You will need to call ImGui::SetAllocatorFunctions().
+//#define IMGUI_DISABLE_SSE                                 // Disable use of SSE intrinsics even if available
+
+//---- Include imgui_user.h at the end of imgui.h as a convenience
+//#define IMGUI_INCLUDE_IMGUI_USER_H
+
+//---- Pack colors to BGRA8 instead of RGBA8 (to avoid converting from one to another)
+//#define IMGUI_USE_BGRA_PACKED_COLOR
+
+//---- Use 32-bit for ImWchar (default is 16-bit) to support unicode planes 1-16. (e.g. point beyond 0xFFFF like emoticons, dingbats, symbols, shapes, ancient languages, etc...)
+//#define IMGUI_USE_WCHAR32
+
+//---- Avoid multiple STB libraries implementations, or redefine path/filenames to prioritize another version
+// By default the embedded implementations are declared static and not available outside of Dear ImGui sources files.
+//#define IMGUI_STB_TRUETYPE_FILENAME   "my_folder/stb_truetype.h"
+//#define IMGUI_STB_RECT_PACK_FILENAME  "my_folder/stb_rect_pack.h"
+//#define IMGUI_STB_SPRINTF_FILENAME    "my_folder/stb_sprintf.h"    // only used if enabled
+//#define IMGUI_DISABLE_STB_TRUETYPE_IMPLEMENTATION
+//#define IMGUI_DISABLE_STB_RECT_PACK_IMPLEMENTATION
+
+//---- Use stb_sprintf.h for a faster implementation of vsnprintf instead of the one from libc (unless IMGUI_DISABLE_DEFAULT_FORMAT_FUNCTIONS is defined)
+// Compatibility checks of arguments and formats done by clang and GCC will be disabled in order to support the extra formats provided by stb_sprintf.h.
+//#define IMGUI_USE_STB_SPRINTF
+
+//---- Use FreeType to build and rasterize the font atlas (instead of stb_truetype which is embedded by default in Dear ImGui)
+// Requires FreeType headers to be available in the include path. Requires program to be compiled with 'misc/freetype/imgui_freetype.cpp' (in this repository) + the FreeType library (not provided).
+// On Windows you may use vcpkg with 'vcpkg install freetype --triplet=x64-windows' + 'vcpkg integrate install'.
+//#define IMGUI_ENABLE_FREETYPE
+
+//---- Use stb_truetype to build and rasterize the font atlas (default)
+// The only purpose of this define is if you want force compilation of the stb_truetype backend ALONG with the FreeType backend.
+//#define IMGUI_ENABLE_STB_TRUETYPE
+
+//---- Define constructor and implicit cast operators to convert back<>forth between your math types and ImVec2/ImVec4.
+// This will be inlined as part of ImVec2 and ImVec4 class declarations.
+/*
+#define IM_VEC2_CLASS_EXTRA                                                     \
+        constexpr ImVec2(const MyVec2& f) : x(f.x), y(f.y) {}                   \
+        operator MyVec2() const { return MyVec2(x,y); }
+
+#define IM_VEC4_CLASS_EXTRA                                                     \
+        constexpr ImVec4(const MyVec4& f) : x(f.x), y(f.y), z(f.z), w(f.w) {}   \
+        operator MyVec4() const { return MyVec4(x,y,z,w); }
+*/
+//---- ...Or use Dear ImGui's own very basic math operators.
+//#define IMGUI_DEFINE_MATH_OPERATORS
+
+//---- Use 32-bit vertex indices (default is 16-bit) is one way to allow large meshes with more than 64K vertices.
+// Your renderer backend will need to support it (most example renderer backends support both 16/32-bit indices).
+// Another way to allow large meshes while keeping 16-bit indices is to handle ImDrawCmd::VtxOffset in your renderer.
+// Read about ImGuiBackendFlags_RendererHasVtxOffset for details.
+//#define ImDrawIdx unsigned int
+
+//---- Override ImDrawCallback signature (will need to modify renderer backends accordingly)
+//struct ImDrawList;
+//struct ImDrawCmd;
+//typedef void (*MyImDrawCallback)(const ImDrawList* draw_list, const ImDrawCmd* cmd, void* my_renderer_user_data);
+//#define ImDrawCallback MyImDrawCallback
+
+//---- Debug Tools: Macro to break in Debugger
+// (use 'Metrics->Tools->Item Picker' to pick widgets with the mouse and break into them for easy debugging.)
+//#define IM_DEBUG_BREAK  IM_ASSERT(0)
+//#define IM_DEBUG_BREAK  __debugbreak()
+
+//---- Debug Tools: Enable slower asserts
+//#define IMGUI_DEBUG_PARANOID
+
+//---- Tip: You can add extra functions within the ImGui:: namespace, here or in your own headers files.
+/*
+namespace ImGui
+{
+    void MyFunction(const char* name, const MyMatrix44& v);
+}
+*/
+
+#include "imconfig-SFML.h"

examples/sound_stage/imgui-SFML.h

@@ -0,0 +1,139 @@
+#ifndef IMGUI_SFML_H
+#define IMGUI_SFML_H
+
+#include <SFML/Graphics/Color.hpp>
+#include <SFML/Graphics/Rect.hpp>
+#include <SFML/System/Time.hpp>
+#include <SFML/System/Vector2.hpp>
+#include <SFML/Window/Joystick.hpp>
+
+#include "imgui-SFML_export.h"
+
+#if __cplusplus >= 201703L // C++17 and above
+#define IMGUI_SFML_NODISCARD [[nodiscard]]
+#else
+#define IMGUI_SFML_NODISCARD
+#endif
+
+namespace sf {
+class Event;
+class RenderTarget;
+class RenderTexture;
+class RenderWindow;
+class Sprite;
+class Texture;
+class Window;
+}
+
+namespace ImGui {
+namespace SFML {
+IMGUI_SFML_NODISCARD IMGUI_SFML_API bool Init(sf::RenderWindow& window,
+                                              bool loadDefaultFont = true);
+IMGUI_SFML_NODISCARD IMGUI_SFML_API bool Init(sf::Window& window, sf::RenderTarget& target,
+                                              bool loadDefaultFont = true);
+IMGUI_SFML_NODISCARD IMGUI_SFML_API bool Init(sf::Window& window, const sf::Vector2f& displaySize,
+                                              bool loadDefaultFont = true);
+
+IMGUI_SFML_API void SetCurrentWindow(const sf::Window& window);
+IMGUI_SFML_API void ProcessEvent(const sf::Event& event); // DEPRECATED: use (window,
+                                                          // event) overload
+IMGUI_SFML_API void ProcessEvent(const sf::Window& window, const sf::Event& event);
+
+IMGUI_SFML_API void Update(sf::RenderWindow& window, sf::Time dt);
+IMGUI_SFML_API void Update(sf::Window& window, sf::RenderTarget& target, sf::Time dt);
+IMGUI_SFML_API void Update(const sf::Vector2i& mousePos, const sf::Vector2f& displaySize,
+                           sf::Time dt);
+
+IMGUI_SFML_API void Render(sf::RenderWindow& target);
+IMGUI_SFML_API void Render(sf::RenderTarget& target);
+IMGUI_SFML_API void Render();
+
+IMGUI_SFML_API void Shutdown(const sf::Window& window);
+// Shuts down all ImGui contexts
+IMGUI_SFML_API void Shutdown();
+
+IMGUI_SFML_NODISCARD IMGUI_SFML_API bool UpdateFontTexture();
+IMGUI_SFML_API sf::Texture& GetFontTexture();
+
+// joystick functions
+IMGUI_SFML_API void SetActiveJoystickId(unsigned int joystickId);
+IMGUI_SFML_API void SetJoystickDPadThreshold(float threshold);
+IMGUI_SFML_API void SetJoystickLStickThreshold(float threshold);
+IMGUI_SFML_API void SetJoystickRStickThreshold(float threshold);
+IMGUI_SFML_API void SetJoystickLTriggerThreshold(float threshold);
+IMGUI_SFML_API void SetJoystickRTriggerThreshold(float threshold);
+
+IMGUI_SFML_API void SetJoystickMapping(int key, unsigned int joystickButton);
+IMGUI_SFML_API void SetDPadXAxis(sf::Joystick::Axis dPadXAxis, bool inverted = false);
+IMGUI_SFML_API void SetDPadYAxis(sf::Joystick::Axis dPadYAxis, bool inverted = false);
+IMGUI_SFML_API void SetLStickXAxis(sf::Joystick::Axis lStickXAxis, bool inverted = false);
+IMGUI_SFML_API void SetLStickYAxis(sf::Joystick::Axis lStickYAxis, bool inverted = false);
+IMGUI_SFML_API void SetRStickXAxis(sf::Joystick::Axis rStickXAxis, bool inverted = false);
+IMGUI_SFML_API void SetRStickYAxis(sf::Joystick::Axis rStickYAxis, bool inverted = false);
+IMGUI_SFML_API void SetLTriggerAxis(sf::Joystick::Axis lTriggerAxis);
+IMGUI_SFML_API void SetRTriggerAxis(sf::Joystick::Axis rTriggerAxis);
+} // end of namespace SFML
+
+// custom SFML overloads for ImGui widgets
+
+// Image overloads for sf::Texture
+IMGUI_SFML_API void Image(const sf::Texture& texture, const sf::Color& tintColor = sf::Color::White,
+                          const sf::Color& borderColor = sf::Color::Transparent);
+IMGUI_SFML_API void Image(const sf::Texture& texture, const sf::Vector2f& size,
+                          const sf::Color& tintColor = sf::Color::White,
+                          const sf::Color& borderColor = sf::Color::Transparent);
+
+// Image overloads for sf::RenderTexture
+IMGUI_SFML_API void Image(const sf::RenderTexture& texture,
+                          const sf::Color& tintColor = sf::Color::White,
+                          const sf::Color& borderColor = sf::Color::Transparent);
+IMGUI_SFML_API void Image(const sf::RenderTexture& texture, const sf::Vector2f& size,
+                          const sf::Color& tintColor = sf::Color::White,
+                          const sf::Color& borderColor = sf::Color::Transparent);
+
+// Image overloads for sf::Sprite
+IMGUI_SFML_API void Image(const sf::Sprite& sprite, const sf::Color& tintColor = sf::Color::White,
+                          const sf::Color& borderColor = sf::Color::Transparent);
+IMGUI_SFML_API void Image(const sf::Sprite& sprite, const sf::Vector2f& size,
+                          const sf::Color& tintColor = sf::Color::White,
+                          const sf::Color& borderColor = sf::Color::Transparent);
+
+// ImageButton overloads for sf::Texture
+IMGUI_SFML_API bool ImageButton(const sf::Texture& texture, const int framePadding = -1,
+                                const sf::Color& bgColor = sf::Color::Transparent,
+                                const sf::Color& tintColor = sf::Color::White);
+IMGUI_SFML_API bool ImageButton(const sf::Texture& texture, const sf::Vector2f& size,
+                                const int framePadding = -1,
+                                const sf::Color& bgColor = sf::Color::Transparent,
+                                const sf::Color& tintColor = sf::Color::White);
+
+// ImageButton overloads for sf::RenderTexture
+IMGUI_SFML_API bool ImageButton(const sf::RenderTexture& texture, const int framePadding = -1,
+                                const sf::Color& bgColor = sf::Color::Transparent,
+                                const sf::Color& tintColor = sf::Color::White);
+IMGUI_SFML_API bool ImageButton(const sf::RenderTexture& texture, const sf::Vector2f& size,
+                                const int framePadding = -1,
+                                const sf::Color& bgColor = sf::Color::Transparent,
+                                const sf::Color& tintColor = sf::Color::White);
+
+// ImageButton overloads for sf::Sprite
+IMGUI_SFML_API bool ImageButton(const sf::Sprite& sprite, const int framePadding = -1,
+                                const sf::Color& bgColor = sf::Color::Transparent,
+                                const sf::Color& tintColor = sf::Color::White);
+IMGUI_SFML_API bool ImageButton(const sf::Sprite& sprite, const sf::Vector2f& size,
+                                const int framePadding = -1,
+                                const sf::Color& bgColor = sf::Color::Transparent,
+                                const sf::Color& tintColor = sf::Color::White);
+
+// Draw_list overloads. All positions are in relative coordinates (relative to top-left of the
+// current window)
+IMGUI_SFML_API void DrawLine(const sf::Vector2f& a, const sf::Vector2f& b, const sf::Color& col,
+                             float thickness = 1.0f);
+IMGUI_SFML_API void DrawRect(const sf::FloatRect& rect, const sf::Color& color,
+                             float rounding = 0.0f, int rounding_corners = 0x0F,
+                             float thickness = 1.0f);
+IMGUI_SFML_API void DrawRectFilled(const sf::FloatRect& rect, const sf::Color& color,
+                                   float rounding = 0.0f, int rounding_corners = 0x0F);
+} // end of namespace ImGui
+
+#endif //# IMGUI_SFML_H

examples/sound_stage/imgui-SFML_export.h

@@ -0,0 +1,25 @@
+#ifndef IMGUI_SFML_EXPORT_H
+#define IMGUI_SFML_EXPORT_H
+
+#if IMGUI_SFML_SHARED_LIB
+#if _WIN32
+#ifdef IMGUI_SFML_EXPORTS
+#define IMGUI_SFML_API __declspec(dllexport)
+#define IMGUI_API __declspec(dllexport)
+#else
+#define IMGUI_SFML_API __declspec(dllimport)
+#define IMGUI_API __declspec(dllexport)
+#endif
+#elif __GNUC__ >= 4
+#define IMGUI_SFML_API __attribute__((visibility("default")))
+#define IMGUI_API __attribute__((visibility("default")))
+#else
+#define IMGUI_SFML_API
+#define IMGUI_API
+#endif
+#else
+#define IMGUI_SFML_API
+#define IMGUI_API
+#endif
+
+#endif

examples/sound_stage/imgui_stdlib.cpp

@@ -0,0 +1,75 @@
+// dear imgui: wrappers for C++ standard library (STL) types (std::string, etc.)
+// This is also an example of how you may wrap your own similar types.
+
+// Changelog:
+// - v0.10: Initial version. Added InputText() / InputTextMultiline() calls with std::string
+
+// See more C++ related extension (fmt, RAII, syntaxis sugar) on Wiki:
+//   https://github.com/ocornut/imgui/wiki/Useful-Extensions#cness
+
+#include "imgui.h"
+#include "imgui_stdlib.h"
+
+struct InputTextCallback_UserData
+{
+    std::string*            Str;
+    ImGuiInputTextCallback  ChainCallback;
+    void*                   ChainCallbackUserData;
+};
+
+static int InputTextCallback(ImGuiInputTextCallbackData* data)
+{
+    InputTextCallback_UserData* user_data = (InputTextCallback_UserData*)data->UserData;
+    if (data->EventFlag == ImGuiInputTextFlags_CallbackResize)
+    {
+        // Resize string callback
+        // If for some reason we refuse the new length (BufTextLen) and/or capacity (BufSize) we need to set them back to what we want.
+        std::string* str = user_data->Str;
+        IM_ASSERT(data->Buf == str->c_str());
+        str->resize(data->BufTextLen);
+        data->Buf = (char*)str->c_str();
+    }
+    else if (user_data->ChainCallback)
+    {
+        // Forward to user callback, if any
+        data->UserData = user_data->ChainCallbackUserData;
+        return user_data->ChainCallback(data);
+    }
+    return 0;
+}
+
+bool ImGui::InputText(const char* label, std::string* str, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, void* user_data)
+{
+    IM_ASSERT((flags & ImGuiInputTextFlags_CallbackResize) == 0);
+    flags |= ImGuiInputTextFlags_CallbackResize;
+
+    InputTextCallback_UserData cb_user_data;
+    cb_user_data.Str = str;
+    cb_user_data.ChainCallback = callback;
+    cb_user_data.ChainCallbackUserData = user_data;
+    return InputText(label, (char*)str->c_str(), str->capacity() + 1, flags, InputTextCallback, &cb_user_data);
+}
+
+bool ImGui::InputTextMultiline(const char* label, std::string* str, const ImVec2& size, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, void* user_data)
+{
+    IM_ASSERT((flags & ImGuiInputTextFlags_CallbackResize) == 0);
+    flags |= ImGuiInputTextFlags_CallbackResize;
+
+    InputTextCallback_UserData cb_user_data;
+    cb_user_data.Str = str;
+    cb_user_data.ChainCallback = callback;
+    cb_user_data.ChainCallbackUserData = user_data;
+    return InputTextMultiline(label, (char*)str->c_str(), str->capacity() + 1, size, flags, InputTextCallback, &cb_user_data);
+}
+
+bool ImGui::InputTextWithHint(const char* label, const char* hint, std::string* str, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, void* user_data)
+{
+    IM_ASSERT((flags & ImGuiInputTextFlags_CallbackResize) == 0);
+    flags |= ImGuiInputTextFlags_CallbackResize;
+
+    InputTextCallback_UserData cb_user_data;
+    cb_user_data.Str = str;
+    cb_user_data.ChainCallback = callback;
+    cb_user_data.ChainCallbackUserData = user_data;
+    return InputTextWithHint(label, hint, (char*)str->c_str(), str->capacity() + 1, flags, InputTextCallback, &cb_user_data);
+}

examples/sound_stage/imgui_stdlib.h

@@ -0,0 +1,21 @@
+// dear imgui: wrappers for C++ standard library (STL) types (std::string, etc.)
+// This is also an example of how you may wrap your own similar types.
+
+// Changelog:
+// - v0.10: Initial version. Added InputText() / InputTextMultiline() calls with std::string
+
+// See more C++ related extension (fmt, RAII, syntaxis sugar) on Wiki:
+//   https://github.com/ocornut/imgui/wiki/Useful-Extensions#cness
+
+#pragma once
+
+#include <string>
+
+namespace ImGui
+{
+    // ImGui::InputText() with std::string
+    // Because text input needs dynamic resizing, we need to setup a callback to grow the capacity
+    IMGUI_API bool  InputText(const char* label, std::string* str, ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+    IMGUI_API bool  InputTextMultiline(const char* label, std::string* str, const ImVec2& size = ImVec2(0, 0), ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+    IMGUI_API bool  InputTextWithHint(const char* label, const char* hint, std::string* str, ImGuiInputTextFlags flags = 0, ImGuiInputTextCallback callback = nullptr, void* user_data = nullptr);
+}

examples/sound_stage/imstb_rectpack.h

@@ -0,0 +1,627 @@
+// [DEAR IMGUI]
+// This is a slightly modified version of stb_rect_pack.h 1.01.
+// Grep for [DEAR IMGUI] to find the changes.
+// 
+// stb_rect_pack.h - v1.01 - public domain - rectangle packing
+// Sean Barrett 2014
+//
+// Useful for e.g. packing rectangular textures into an atlas.
+// Does not do rotation.
+//
+// Before #including,
+//
+//    #define STB_RECT_PACK_IMPLEMENTATION
+//
+// in the file that you want to have the implementation.
+//
+// Not necessarily the awesomest packing method, but better than
+// the totally naive one in stb_truetype (which is primarily what
+// this is meant to replace).
+//
+// Has only had a few tests run, may have issues.
+//
+// More docs to come.
+//
+// No memory allocations; uses qsort() and assert() from stdlib.
+// Can override those by defining STBRP_SORT and STBRP_ASSERT.
+//
+// This library currently uses the Skyline Bottom-Left algorithm.
+//
+// Please note: better rectangle packers are welcome! Please
+// implement them to the same API, but with a different init
+// function.
+//
+// Credits
+//
+//  Library
+//    Sean Barrett
+//  Minor features
+//    Martins Mozeiko
+//    github:IntellectualKitty
+//
+//  Bugfixes / warning fixes
+//    Jeremy Jaussaud
+//    Fabian Giesen
+//
+// Version history:
+//
+//     1.01  (2021-07-11)  always use large rect mode, expose STBRP__MAXVAL in public section
+//     1.00  (2019-02-25)  avoid small space waste; gracefully fail too-wide rectangles
+//     0.99  (2019-02-07)  warning fixes
+//     0.11  (2017-03-03)  return packing success/fail result
+//     0.10  (2016-10-25)  remove cast-away-const to avoid warnings
+//     0.09  (2016-08-27)  fix compiler warnings
+//     0.08  (2015-09-13)  really fix bug with empty rects (w=0 or h=0)
+//     0.07  (2015-09-13)  fix bug with empty rects (w=0 or h=0)
+//     0.06  (2015-04-15)  added STBRP_SORT to allow replacing qsort
+//     0.05:  added STBRP_ASSERT to allow replacing assert
+//     0.04:  fixed minor bug in STBRP_LARGE_RECTS support
+//     0.01:  initial release
+//
+// LICENSE
+//
+//   See end of file for license information.
+
+//////////////////////////////////////////////////////////////////////////////
+//
+//       INCLUDE SECTION
+//
+
+#ifndef STB_INCLUDE_STB_RECT_PACK_H
+#define STB_INCLUDE_STB_RECT_PACK_H
+
+#define STB_RECT_PACK_VERSION  1
+
+#ifdef STBRP_STATIC
+#define STBRP_DEF static
+#else
+#define STBRP_DEF extern
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct stbrp_context stbrp_context;
+typedef struct stbrp_node    stbrp_node;
+typedef struct stbrp_rect    stbrp_rect;
+
+typedef int            stbrp_coord;
+
+#define STBRP__MAXVAL  0x7fffffff
+// Mostly for internal use, but this is the maximum supported coordinate value.
+
+STBRP_DEF int stbrp_pack_rects (stbrp_context *context, stbrp_rect *rects, int num_rects);
+// Assign packed locations to rectangles. The rectangles are of type
+// 'stbrp_rect' defined below, stored in the array 'rects', and there
+// are 'num_rects' many of them.
+//
+// Rectangles which are successfully packed have the 'was_packed' flag
+// set to a non-zero value and 'x' and 'y' store the minimum location
+// on each axis (i.e. bottom-left in cartesian coordinates, top-left
+// if you imagine y increasing downwards). Rectangles which do not fit
+// have the 'was_packed' flag set to 0.
+//
+// You should not try to access the 'rects' array from another thread
+// while this function is running, as the function temporarily reorders
+// the array while it executes.
+//
+// To pack into another rectangle, you need to call stbrp_init_target
+// again. To continue packing into the same rectangle, you can call
+// this function again. Calling this multiple times with multiple rect
+// arrays will probably produce worse packing results than calling it
+// a single time with the full rectangle array, but the option is
+// available.
+//
+// The function returns 1 if all of the rectangles were successfully
+// packed and 0 otherwise.
+
+struct stbrp_rect
+{
+   // reserved for your use:
+   int            id;
+
+   // input:
+   stbrp_coord    w, h;
+
+   // output:
+   stbrp_coord    x, y;
+   int            was_packed;  // non-zero if valid packing
+
+}; // 16 bytes, nominally
+
+
+STBRP_DEF void stbrp_init_target (stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes);
+// Initialize a rectangle packer to:
+//    pack a rectangle that is 'width' by 'height' in dimensions
+//    using temporary storage provided by the array 'nodes', which is 'num_nodes' long
+//
+// You must call this function every time you start packing into a new target.
+//
+// There is no "shutdown" function. The 'nodes' memory must stay valid for
+// the following stbrp_pack_rects() call (or calls), but can be freed after
+// the call (or calls) finish.
+//
+// Note: to guarantee best results, either:
+//       1. make sure 'num_nodes' >= 'width'
+//   or  2. call stbrp_allow_out_of_mem() defined below with 'allow_out_of_mem = 1'
+//
+// If you don't do either of the above things, widths will be quantized to multiples
+// of small integers to guarantee the algorithm doesn't run out of temporary storage.
+//
+// If you do #2, then the non-quantized algorithm will be used, but the algorithm
+// may run out of temporary storage and be unable to pack some rectangles.
+
+STBRP_DEF void stbrp_setup_allow_out_of_mem (stbrp_context *context, int allow_out_of_mem);
+// Optionally call this function after init but before doing any packing to
+// change the handling of the out-of-temp-memory scenario, described above.
+// If you call init again, this will be reset to the default (false).
+
+
+STBRP_DEF void stbrp_setup_heuristic (stbrp_context *context, int heuristic);
+// Optionally select which packing heuristic the library should use. Different
+// heuristics will produce better/worse results for different data sets.
+// If you call init again, this will be reset to the default.
+
+enum
+{
+   STBRP_HEURISTIC_Skyline_default=0,
+   STBRP_HEURISTIC_Skyline_BL_sortHeight = STBRP_HEURISTIC_Skyline_default,
+   STBRP_HEURISTIC_Skyline_BF_sortHeight
+};
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// the details of the following structures don't matter to you, but they must
+// be visible so you can handle the memory allocations for them
+
+struct stbrp_node
+{
+   stbrp_coord  x,y;
+   stbrp_node  *next;
+};
+
+struct stbrp_context
+{
+   int width;
+   int height;
+   int align;
+   int init_mode;
+   int heuristic;
+   int num_nodes;
+   stbrp_node *active_head;
+   stbrp_node *free_head;
+   stbrp_node extra[2]; // we allocate two extra nodes so optimal user-node-count is 'width' not 'width+2'
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+//     IMPLEMENTATION SECTION
+//
+
+#ifdef STB_RECT_PACK_IMPLEMENTATION
+#ifndef STBRP_SORT
+#include <stdlib.h>
+#define STBRP_SORT qsort
+#endif
+
+#ifndef STBRP_ASSERT
+#include <assert.h>
+#define STBRP_ASSERT assert
+#endif
+
+#ifdef _MSC_VER
+#define STBRP__NOTUSED(v)  (void)(v)
+#define STBRP__CDECL       __cdecl
+#else
+#define STBRP__NOTUSED(v)  (void)sizeof(v)
+#define STBRP__CDECL
+#endif
+
+enum
+{
+   STBRP__INIT_skyline = 1
+};
+
+STBRP_DEF void stbrp_setup_heuristic(stbrp_context *context, int heuristic)
+{
+   switch (context->init_mode) {
+      case STBRP__INIT_skyline:
+         STBRP_ASSERT(heuristic == STBRP_HEURISTIC_Skyline_BL_sortHeight || heuristic == STBRP_HEURISTIC_Skyline_BF_sortHeight);
+         context->heuristic = heuristic;
+         break;
+      default:
+         STBRP_ASSERT(0);
+   }
+}
+
+STBRP_DEF void stbrp_setup_allow_out_of_mem(stbrp_context *context, int allow_out_of_mem)
+{
+   if (allow_out_of_mem)
+      // if it's ok to run out of memory, then don't bother aligning them;
+      // this gives better packing, but may fail due to OOM (even though
+      // the rectangles easily fit). @TODO a smarter approach would be to only
+      // quantize once we've hit OOM, then we could get rid of this parameter.
+      context->align = 1;
+   else {
+      // if it's not ok to run out of memory, then quantize the widths
+      // so that num_nodes is always enough nodes.
+      //
+      // I.e. num_nodes * align >= width
+      //                  align >= width / num_nodes
+      //                  align = ceil(width/num_nodes)
+
+      context->align = (context->width + context->num_nodes-1) / context->num_nodes;
+   }
+}
+
+STBRP_DEF void stbrp_init_target(stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes)
+{
+   int i;
+
+   for (i=0; i < num_nodes-1; ++i)
+      nodes[i].next = &nodes[i+1];
+   nodes[i].next = NULL;
+   context->init_mode = STBRP__INIT_skyline;
+   context->heuristic = STBRP_HEURISTIC_Skyline_default;
+   context->free_head = &nodes[0];
+   context->active_head = &context->extra[0];
+   context->width = width;
+   context->height = height;
+   context->num_nodes = num_nodes;
+   stbrp_setup_allow_out_of_mem(context, 0);
+
+   // node 0 is the full width, node 1 is the sentinel (lets us not store width explicitly)
+   context->extra[0].x = 0;
+   context->extra[0].y = 0;
+   context->extra[0].next = &context->extra[1];
+   context->extra[1].x = (stbrp_coord) width;
+   context->extra[1].y = (1<<30);
+   context->extra[1].next = NULL;
+}
+
+// find minimum y position if it starts at x1
+static int stbrp__skyline_find_min_y(stbrp_context *c, stbrp_node *first, int x0, int width, int *pwaste)
+{
+   stbrp_node *node = first;
+   int x1 = x0 + width;
+   int min_y, visited_width, waste_area;
+
+   STBRP__NOTUSED(c);
+
+   STBRP_ASSERT(first->x <= x0);
+
+   #if 0
+   // skip in case we're past the node
+   while (node->next->x <= x0)
+      ++node;
+   #else
+   STBRP_ASSERT(node->next->x > x0); // we ended up handling this in the caller for efficiency
+   #endif
+
+   STBRP_ASSERT(node->x <= x0);
+
+   min_y = 0;
+   waste_area = 0;
+   visited_width = 0;
+   while (node->x < x1) {
+      if (node->y > min_y) {
+         // raise min_y higher.
+         // we've accounted for all waste up to min_y,
+         // but we'll now add more waste for everything we've visted
+         waste_area += visited_width * (node->y - min_y);
+         min_y = node->y;
+         // the first time through, visited_width might be reduced
+         if (node->x < x0)
+            visited_width += node->next->x - x0;
+         else
+            visited_width += node->next->x - node->x;
+      } else {
+         // add waste area
+         int under_width = node->next->x - node->x;
+         if (under_width + visited_width > width)
+            under_width = width - visited_width;
+         waste_area += under_width * (min_y - node->y);
+         visited_width += under_width;
+      }
+      node = node->next;
+   }
+
+   *pwaste = waste_area;
+   return min_y;
+}
+
+typedef struct
+{
+   int x,y;
+   stbrp_node **prev_link;
+} stbrp__findresult;
+
+static stbrp__findresult stbrp__skyline_find_best_pos(stbrp_context *c, int width, int height)
+{
+   int best_waste = (1<<30), best_x, best_y = (1 << 30);
+   stbrp__findresult fr;
+   stbrp_node **prev, *node, *tail, **best = NULL;
+
+   // align to multiple of c->align
+   width = (width + c->align - 1);
+   width -= width % c->align;
+   STBRP_ASSERT(width % c->align == 0);
+
+   // if it can't possibly fit, bail immediately
+   if (width > c->width || height > c->height) {
+      fr.prev_link = NULL;
+      fr.x = fr.y = 0;
+      return fr;
+   }
+
+   node = c->active_head;
+   prev = &c->active_head;
+   while (node->x + width <= c->width) {
+      int y,waste;
+      y = stbrp__skyline_find_min_y(c, node, node->x, width, &waste);
+      if (c->heuristic == STBRP_HEURISTIC_Skyline_BL_sortHeight) { // actually just want to test BL
+         // bottom left
+         if (y < best_y) {
+            best_y = y;
+            best = prev;
+         }
+      } else {
+         // best-fit
+         if (y + height <= c->height) {
+            // can only use it if it first vertically
+            if (y < best_y || (y == best_y && waste < best_waste)) {
+               best_y = y;
+               best_waste = waste;
+               best = prev;
+            }
+         }
+      }
+      prev = &node->next;
+      node = node->next;
+   }
+
+   best_x = (best == NULL) ? 0 : (*best)->x;
+
+   // if doing best-fit (BF), we also have to try aligning right edge to each node position
+   //
+   // e.g, if fitting
+   //
+   //     ____________________
+   //    |____________________|
+   //
+   //            into
+   //
+   //   |                         |
+   //   |             ____________|
+   //   |____________|
+   //
+   // then right-aligned reduces waste, but bottom-left BL is always chooses left-aligned
+   //
+   // This makes BF take about 2x the time
+
+   if (c->heuristic == STBRP_HEURISTIC_Skyline_BF_sortHeight) {
+      tail = c->active_head;
+      node = c->active_head;
+      prev = &c->active_head;
+      // find first node that's admissible
+      while (tail->x < width)
+         tail = tail->next;
+      while (tail) {
+         int xpos = tail->x - width;
+         int y,waste;
+         STBRP_ASSERT(xpos >= 0);
+         // find the left position that matches this
+         while (node->next->x <= xpos) {
+            prev = &node->next;
+            node = node->next;
+         }
+         STBRP_ASSERT(node->next->x > xpos && node->x <= xpos);
+         y = stbrp__skyline_find_min_y(c, node, xpos, width, &waste);
+         if (y + height <= c->height) {
+            if (y <= best_y) {
+               if (y < best_y || waste < best_waste || (waste==best_waste && xpos < best_x)) {
+                  best_x = xpos;
+                  //STBRP_ASSERT(y <= best_y); [DEAR IMGUI]
+                  best_y = y;
+                  best_waste = waste;
+                  best = prev;
+               }
+            }
+         }
+         tail = tail->next;
+      }
+   }
+
+   fr.prev_link = best;
+   fr.x = best_x;
+   fr.y = best_y;
+   return fr;
+}
+
+static stbrp__findresult stbrp__skyline_pack_rectangle(stbrp_context *context, int width, int height)
+{
+   // find best position according to heuristic
+   stbrp__findresult res = stbrp__skyline_find_best_pos(context, width, height);
+   stbrp_node *node, *cur;
+
+   // bail if:
+   //    1. it failed
+   //    2. the best node doesn't fit (we don't always check this)
+   //    3. we're out of memory
+   if (res.prev_link == NULL || res.y + height > context->height || context->free_head == NULL) {
+      res.prev_link = NULL;
+      return res;
+   }
+
+   // on success, create new node
+   node = context->free_head;
+   node->x = (stbrp_coord) res.x;
+   node->y = (stbrp_coord) (res.y + height);
+
+   context->free_head = node->next;
+
+   // insert the new node into the right starting point, and
+   // let 'cur' point to the remaining nodes needing to be
+   // stiched back in
+
+   cur = *res.prev_link;
+   if (cur->x < res.x) {
+      // preserve the existing one, so start testing with the next one
+      stbrp_node *next = cur->next;
+      cur->next = node;
+      cur = next;
+   } else {
+      *res.prev_link = node;
+   }
+
+   // from here, traverse cur and free the nodes, until we get to one
+   // that shouldn't be freed
+   while (cur->next && cur->next->x <= res.x + width) {
+      stbrp_node *next = cur->next;
+      // move the current node to the free list
+      cur->next = context->free_head;
+      context->free_head = cur;
+      cur = next;
+   }
+
+   // stitch the list back in
+   node->next = cur;
+
+   if (cur->x < res.x + width)
+      cur->x = (stbrp_coord) (res.x + width);
+
+#ifdef _DEBUG
+   cur = context->active_head;
+   while (cur->x < context->width) {
+      STBRP_ASSERT(cur->x < cur->next->x);
+      cur = cur->next;
+   }
+   STBRP_ASSERT(cur->next == NULL);
+
+   {
+      int count=0;
+      cur = context->active_head;
+      while (cur) {
+         cur = cur->next;
+         ++count;
+      }
+      cur = context->free_head;
+      while (cur) {
+         cur = cur->next;
+         ++count;
+      }
+      STBRP_ASSERT(count == context->num_nodes+2);
+   }
+#endif
+
+   return res;
+}
+
+static int STBRP__CDECL rect_height_compare(const void *a, const void *b)
+{
+   const stbrp_rect *p = (const stbrp_rect *) a;
+   const stbrp_rect *q = (const stbrp_rect *) b;
+   if (p->h > q->h)
+      return -1;
+   if (p->h < q->h)
+      return  1;
+   return (p->w > q->w) ? -1 : (p->w < q->w);
+}
+
+static int STBRP__CDECL rect_original_order(const void *a, const void *b)
+{
+   const stbrp_rect *p = (const stbrp_rect *) a;
+   const stbrp_rect *q = (const stbrp_rect *) b;
+   return (p->was_packed < q->was_packed) ? -1 : (p->was_packed > q->was_packed);
+}
+
+STBRP_DEF int stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int num_rects)
+{
+   int i, all_rects_packed = 1;
+
+   // we use the 'was_packed' field internally to allow sorting/unsorting
+   for (i=0; i < num_rects; ++i) {
+      rects[i].was_packed = i;
+   }
+
+   // sort according to heuristic
+   STBRP_SORT(rects, num_rects, sizeof(rects[0]), rect_height_compare);
+
+   for (i=0; i < num_rects; ++i) {
+      if (rects[i].w == 0 || rects[i].h == 0) {
+         rects[i].x = rects[i].y = 0;  // empty rect needs no space
+      } else {
+         stbrp__findresult fr = stbrp__skyline_pack_rectangle(context, rects[i].w, rects[i].h);
+         if (fr.prev_link) {
+            rects[i].x = (stbrp_coord) fr.x;
+            rects[i].y = (stbrp_coord) fr.y;
+         } else {
+            rects[i].x = rects[i].y = STBRP__MAXVAL;
+         }
+      }
+   }
+
+   // unsort
+   STBRP_SORT(rects, num_rects, sizeof(rects[0]), rect_original_order);
+
+   // set was_packed flags and all_rects_packed status
+   for (i=0; i < num_rects; ++i) {
+      rects[i].was_packed = !(rects[i].x == STBRP__MAXVAL && rects[i].y == STBRP__MAXVAL);
+      if (!rects[i].was_packed)
+         all_rects_packed = 0;
+   }
+
+   // return the all_rects_packed status
+   return all_rects_packed;
+}
+#endif
+
+/*
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2017 Sean Barrett
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+*/