main.cpp

// Dear ImGui: standalone example application for GLFW + OpenGL 3, using programmable pipeline
// (GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
// Read online: https://github.com/ocornut/imgui/tree/master/docs

#include "imgui.h"
#include "imgui_impl_glfw.h"
#include "imgui_impl_opengl3.h"
#include "implot/implot.h"
#include "implot/implot_internal.h"
#include "imgui-knobs/imgui-knobs.h"
#include "imspinner/imspinner.h"

#include <cmath>
#include <stdio.h>
#define GL_SILENCE_DEPRECATION
#if defined(IMGUI_IMPL_OPENGL_ES2)
#include <GLES2/gl2.h>
#endif
#include <GLFW/glfw3.h> // Will drag system OpenGL headers


// [Win32] Our example includes a copy of glfw3.lib pre-compiled with VS2010 to maximize ease of testing and compatibility with old VS compilers.
// To link with VS2010-era libraries, VS2015+ requires linking with legacy_stdio_definitions.lib, which we do using this pragma.
// Your own project should not be affected, as you are likely to link with a newer binary of GLFW that is adequate for your version of Visual Studio.
#if defined(_MSC_VER) && (_MSC_VER >= 1900) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)
#pragma comment(lib, "legacy_stdio_definitions")
#endif

static void glfw_error_callback(int error, const char* description)
{
    fprintf(stderr, "Glfw Error %d: %s\n", error, description);
}

float to_radian(float deg)
{
    return(deg * (3.14 / 180.0));
}

static float knob_value = 0;


// utility structure for realtime plot
struct ScrollingBuffer {
    int MaxSize;
    int Offset;
    ImVector<ImVec2> Data;
    ScrollingBuffer(int max_size = 2000) {
        MaxSize = max_size;
        Offset = 0;
        Data.reserve(MaxSize);
    }
    void AddPoint(float x, float y) {
        if (Data.size() < MaxSize)
            Data.push_back(ImVec2(x, y));
        else {
            Data[Offset] = ImVec2(x, y);
            Offset = (Offset + 1) % MaxSize;
        }
    }
    void Erase() {
        if (Data.size() > 0) {
            Data.shrink(0);
            Offset = 0;
        }
    }
};

// utility structure for realtime plot
struct RollingBuffer {
    float Span;
    ImVector<ImVec2> Data;
    RollingBuffer() {
        Span = 10.0f;
        Data.reserve(2000);
    }
    void AddPoint(float x, float y) {
        float xmod = fmodf(x, Span);
        if (!Data.empty() && xmod < Data.back().x)
            Data.shrink(0);
        Data.push_back(ImVec2(xmod, y));
    }
};

void Demo_RealtimePlots() {
    ImGui::BulletText("Move your mouse to change the data!");
    ImGui::BulletText("This example assumes 60 FPS. Higher FPS requires larger buffer size.");
    static ScrollingBuffer sdata1, sdata2;
    static RollingBuffer   rdata1, rdata2;
    ImVec2 mouse = ImGui::GetMousePos();
    static float t = 0;
    t += ImGui::GetIO().DeltaTime;
    sdata1.AddPoint(t, mouse.x * 0.0005f);
    rdata1.AddPoint(t, mouse.x * 0.0005f);
    sdata2.AddPoint(t, mouse.y * 0.0005f);
    rdata2.AddPoint(t, mouse.y * 0.0005f);

    static float history = 10.0f;
    ImGui::SliderFloat("History", &history, 1, 30, "%.1f s");
    rdata1.Span = history;
    rdata2.Span = history;

    static ImPlotAxisFlags flags = ImPlotAxisFlags_NoTickLabels | ImPlotAxisFlags_NoTickMarks;

    if (ImPlot::BeginPlot("Scrolling", ImVec2(-1, 250))) {
        ImPlot::SetupAxes("Scrolling Title a", "Scrolling Title b", flags, flags);
        ImPlot::SetupAxisLimits(ImAxis_X1, t - history, t, ImGuiCond_Always);
        ImPlot::SetupAxisLimits(ImAxis_Y1, 0, 1);
        ImPlot::SetNextFillStyle(IMPLOT_AUTO_COL, 0.5f);
        ImPlot::PlotShaded("Mouse X", &sdata1.Data[0].x, &sdata1.Data[0].y, sdata1.Data.size(), -INFINITY, 0, sdata1.Offset, 2 * sizeof(float));
        ImPlot::PlotLine("Mouse Y", &sdata2.Data[0].x, &sdata2.Data[0].y, sdata2.Data.size(), 0, sdata2.Offset, 2 * sizeof(float));
        ImPlot::EndPlot();
    }
    if (ImPlot::BeginPlot("Rolling", ImVec2(-1, 250))) {
        ImPlot::SetupAxes(NULL, NULL, flags, flags);
        ImPlot::SetupAxisLimits(ImAxis_X1, 0, history, ImGuiCond_Always);
        ImPlot::SetupAxisLimits(ImAxis_Y1, 0, 1);
        ImPlot::PlotLine("Mouse X", &rdata1.Data[0].x, &rdata1.Data[0].y, rdata1.Data.size(), 0, 0, 2 * sizeof(float));
        ImPlot::PlotLine("Mouse Y", &rdata2.Data[0].x, &rdata2.Data[0].y, rdata2.Data.size(), 0, 0, 2 * sizeof(float));
        ImPlot::EndPlot();
    }
}


int main(int, char**)
{
    // Setup window
    glfwSetErrorCallback(glfw_error_callback);
    if (!glfwInit())
        return 1;

    // Decide GL+GLSL versions
#if defined(IMGUI_IMPL_OPENGL_ES2)
    // GL ES 2.0 + GLSL 100
    const char* glsl_version = "#version 100";
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
    glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
#elif defined(__APPLE__)
    // GL 3.2 + GLSL 150
    const char* glsl_version = "#version 150";
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 3.2+ only
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);            // Required on Mac
#else
    // GL 3.0 + GLSL 130
    const char* glsl_version = "#version 130";
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
    //glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);  // 3.2+ only
    //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);            // 3.0+ only
#endif

    // Create window with graphics context
    GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+OpenGL3 example", NULL, NULL);
    if (window == NULL)
        return 1;
    glfwMakeContextCurrent(window);
    glfwSwapInterval(1); // Enable vsync

    // Setup Dear ImGui context
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImPlot::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); (void)io;
    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;       // Enable Keyboard Controls
    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;           // Enable Docking
    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;         // Enable Multi-Viewport / Platform Windows
    //io.ConfigViewportsNoAutoMerge = true;
    //io.ConfigViewportsNoTaskBarIcon = true;

    // Setup Dear ImGui style
    ImGui::StyleColorsDark();
    //ImGui::StyleColorsLight();

    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
    ImGuiStyle& style = ImGui::GetStyle();
    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
    {
        style.WindowRounding = 0.0f;
        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
    }

    // Setup Platform/Renderer backends
    ImGui_ImplGlfw_InitForOpenGL(window, true);
    ImGui_ImplOpenGL3_Init(glsl_version);

    // Load Fonts
    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
    // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
    // - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
    // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
    // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
    // - Read 'docs/FONTS.md' for more instructions and details.
    // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
    //io.Fonts->AddFontDefault();
    //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
    //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
    //IM_ASSERT(font != NULL);

    // Our state
    bool show_demo_window = false;
    bool show_playground_window = false;
    bool show_plot_window = false;
    bool show_knob_window = false;
    float r = 50;
    float angle = 0.0f;
    ImVec2 midpoint = {}, point_on_circle = {};

    ImVec4 clear_color = ImVec4(0.168f, 0.394f, 0.534f, 1.00f);

    // Main loop
    while (!glfwWindowShouldClose(window))
    {
        // Poll and handle events (inputs, window resize, etc.)
        // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
        // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
        // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
        // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
        glfwPollEvents();

        // Start the Dear ImGui frame
        ImGui_ImplOpenGL3_NewFrame();
        ImGui_ImplGlfw_NewFrame();
        ImGui::NewFrame();

        ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoDocking | 
                                        ImGuiWindowFlags_NoCollapse | 
                                        ImGuiWindowFlags_MenuBar |
                                        ImGuiWindowFlags_DockNodeHost;
        ImGui::DockSpaceOverViewport(ImGui::GetMainViewport(), ImGuiDockNodeFlags_PassthruCentralNode);

        // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
        if (show_demo_window) {
            ImGui::ShowDemoWindow(&show_demo_window);
        }
        if (show_plot_window) {
            ImPlot::ShowDemoWindow(&show_demo_window);
        }

        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
        {
            static float f = 0.0f;
            static int counter = 0;

            ImGui::Begin("Settings");                          // Create a window called "Hello, world!" and append into it.

            ImGui::Text("Configure the App below.");               // Display some text (you can use a format strings too)
            ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
            ImGui::Checkbox("Playground", &show_playground_window);
            ImGui::Checkbox("Plot Window", &show_plot_window);
            ImGui::Checkbox("Knob Window", &show_knob_window);

            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
                counter++;
            ImGui::SameLine();
            ImGui::Text("counter = %d", counter);

            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
            ImGui::End();

        }

        // 3. Show another simple window.
        if (show_playground_window)
        {
            ImGui::Begin("Playground", &show_playground_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
            ImGui::Text("Hello from Playground!");
            if (ImGui::Button("Close Me"))
                show_playground_window = false;

            Demo_RealtimePlots();
            ImGui::End();
        }

        if (show_knob_window)
        {
            ImGui::Begin("Knob Demo!");
            /** ImGuiKnobVariant_Tick,
                ImGuiKnobVariant_Dot,
                ImGuiKnobVariant_Wiper,
                ImGuiKnobVariant_WiperOnly,
                ImGuiKnobVariant_WiperDot,
                ImGuiKnobVariant_Stepped,
                ImGuiKnobVariant_Space
             **/
            ImGui::BeginGroup();
            if (ImGuiKnobs::Knob("Volume", &knob_value, -6.0f, 6.0f, 0.1f, "%.1fdB", ImGuiKnobVariant_Tick, 100)) {
                // value was changed
            }
            ImGui::SameLine();
            if (ImGuiKnobs::Knob("Volume", &knob_value, -6.0f, 6.0f, 0.1f, "%.1fdB", ImGuiKnobVariant_Dot, 100)) {
                // value was changed
            }
            ImGui::SameLine();
            if (ImGuiKnobs::Knob("Volume", &knob_value, -6.0f, 6.0f, 0.1f, "%.1fdB", ImGuiKnobVariant_Wiper, 100)) {
                // value was changed
            }
            ImGui::SameLine();
            if (ImGuiKnobs::Knob("Volume", &knob_value, -6.0f, 6.0f, 0.1f, "%.1fdB", ImGuiKnobVariant_WiperOnly, 100)) {
                // value was changed
            }
            ImGui::SameLine();
            if (ImGuiKnobs::Knob("Volume", &knob_value, -6.0f, 6.0f, 0.1f, "%.1fdB", ImGuiKnobVariant_WiperDot, 100)) {
                // value was changed
            }
            ImGui::SameLine();
            if (ImGuiKnobs::Knob("Volume", &knob_value, -6.0f, 6.0f, 0.1f, "%.1fdB", ImGuiKnobVariant_Stepped, 100)) {
                // value was changed
            }
            ImGui::SameLine();
            if (ImGuiKnobs::Knob("Volume", &knob_value, -6.0f, 6.0f, 0.1f, "%.1fdB", ImGuiKnobVariant_Space, 100)) {
                // value was changed
            }

            // Simple progress loader/spinner
            ImGui::Text("Loading %c", "|/-\\"[(int)(ImGui::GetTime() / 0.05f) & 3]);

            // Spinners- https://github.com/dalerank/imspinner
            // ImSpinner::Spinner

            ImDrawList* draw_list = ImGui::GetWindowDrawList();
            auto screen_pos = ImGui::GetCursorScreenPos();
            float radius = 50.0;


            //if (angle > 360) angle = 0;
            midpoint = { screen_pos[0] + radius ,screen_pos[1] + radius*2  };
            ImGui::SliderFloat("##float", &angle, 0.0f, 360.0f);

            /* Drawing a circle using Trigonometry for fun */
            point_on_circle[0] = midpoint[0] + r * cosf(to_radian(angle));
            point_on_circle[1] = midpoint[1] + r * sinf(to_radian(angle));
            (angle > 359)? angle=0:angle++;
            
            // Outline - BLUE
            draw_list->AddCircle(midpoint, 50, ImGui::GetColorU32(IM_COL32(0, 0, 255, 255)), 0, 10);

            // Small filled circle for midpoint
            draw_list->AddCircleFilled(midpoint, 5, ImGui::GetColorU32(IM_COL32(255, 0, 255, 255)), 0);

            // Small filled circle on the above circular path
            draw_list->AddCircleFilled(point_on_circle, 3, ImGui::GetColorU32(IM_COL32(255, 0, 0, 255)), 0);

            // Line starting from midpoint to circumference of the circle
            draw_list->AddLine(midpoint,point_on_circle,ImGui::GetColorU32(IM_COL32(255, 0, 0, 255)), 2);

            ImGui::EndGroup();
            
            ImGui::End();

            
        }

        // Rendering
        ImGui::Render();
        int display_w, display_h;
        glfwGetFramebufferSize(window, &display_w, &display_h);
        glViewport(0, 0, display_w, display_h);
        glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
        glClear(GL_COLOR_BUFFER_BIT);
        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
    	
        // Update and Render additional Platform Windows
        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
        {
            GLFWwindow* backup_current_context = glfwGetCurrentContext();
            ImGui::UpdatePlatformWindows();
            ImGui::RenderPlatformWindowsDefault();
            glfwMakeContextCurrent(backup_current_context);
        }

        glfwSwapBuffers(window);
    }

    // Cleanup
    ImGui_ImplOpenGL3_Shutdown();
    ImGui_ImplGlfw_Shutdown();
    ImPlot::DestroyContext();
    ImGui::DestroyContext();

    glfwDestroyWindow(window);
    glfwTerminate();

    return 0;
}