renderer.cpp

#include "ImGui/imgui.h"
#include "ImGui/imgui_internal.h"

Renderer* Renderer::m_pInstance;

Renderer::Renderer()
{
}

Renderer::~Renderer()
{
}

void Renderer::Initialize()
{
    ImGuiIO& io = ImGui::GetIO();

        // This is my example of font initializing
        // First font used for UI
        // Second for rendering, 32.0f is pixel size, not font size.
    io.Fonts->AddFontFromMemoryTTF(g_fRubik, sizeof(g_fRubik), 16.0f, NULL, io.Fonts->GetGlyphRangesCyrillic());
    m_pFont = io.Fonts->AddFontFromMemoryTTF(g_fRubik, sizeof(g_fRubik), 32.0f, NULL, io.Fonts->GetGlyphRangesCyrillic());
}

void Renderer::BeginScene()
{
    ImGui::PushStyleColor(ImGuiCol_WindowBg, ImVec4(0.0f, 0.0f, 0.0f, 0.0f));
    ImGui::Begin("BackBuffer", reinterpret_cast<bool*>(true), ImVec2(0, 0), 0.0f, ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoInputs);

    ImGui::SetWindowPos(ImVec2(0, 0), ImGuiSetCond_Always);
    ImGui::SetWindowSize(ImVec2(ImGui::GetIO().DisplaySize.x, ImGui::GetIO().DisplaySize.y), ImGuiSetCond_Always);
}

void Renderer::DrawScene()
{
    ImGuiIO& io = ImGui::GetIO();

    DrawText(m_pFont,
        TextFormat(META_STRING("%.0f"), io.Framerate), ImVec2(10, lastY), 32.0f, 0xFFFFFFFF);
}

void Renderer::EndScene()
{
    ImGuiWindow* window = ImGui::GetCurrentWindow();
    window->DrawList->PushClipRectFullScreen();

    ImGui::End();
    ImGui::PopStyleColor();
}

float Renderer::DrawText(ImFont* pFont, const std::string& text, const ImVec2& pos, float size, uint32_t color, bool center)
{
    ImGuiWindow* window = ImGui::GetCurrentWindow();

    float a = (color >> 24) & 0xff;
    float r = (color >> 16) & 0xff;
    float g = (color >> 8) & 0xff;
    float b = (color) & 0xff;

    std::stringstream steam(text);
    std::string line;

    float y = 0.0f;
    int i = 0;

    while (std::getline(steam, line))
    {
        ImVec2 textSize = pFont->CalcTextSizeA(size, FLT_MAX, 0.0f, line.c_str());

        if (center)
        {
            window->DrawList->AddText(pFont, size, ImVec2((pos.x - textSize.x / 2.0f) + 1, (pos.y + textSize.y * i) + 1), ImGui::GetColorU32(ImVec4(0, 0, 0, a / 255)), line.c_str());
            window->DrawList->AddText(pFont, size, ImVec2((pos.x - textSize.x / 2.0f) - 1, (pos.y + textSize.y * i) - 1), ImGui::GetColorU32(ImVec4(0, 0, 0, a / 255)), line.c_str());
            window->DrawList->AddText(pFont, size, ImVec2((pos.x - textSize.x / 2.0f) + 1, (pos.y + textSize.y * i) - 1), ImGui::GetColorU32(ImVec4(0, 0, 0, a / 255)), line.c_str());
            window->DrawList->AddText(pFont, size, ImVec2((pos.x - textSize.x / 2.0f) - 1, (pos.y + textSize.y * i) + 1), ImGui::GetColorU32(ImVec4(0, 0, 0, a / 255)), line.c_str());

            window->DrawList->AddText(pFont, size, ImVec2(pos.x - textSize.x / 2.0f, pos.y + textSize.y * i), ImGui::GetColorU32(ImVec4(r / 255, g / 255, b / 255, a / 255)), line.c_str());
        }
        else
        {
            window->DrawList->AddText(pFont, size, ImVec2((pos.x) + 1, (pos.y + textSize.y * i) + 1), ImGui::GetColorU32(ImVec4(0, 0, 0, a / 255)), line.c_str());
            window->DrawList->AddText(pFont, size, ImVec2((pos.x) - 1, (pos.y + textSize.y * i) - 1), ImGui::GetColorU32(ImVec4(0, 0, 0, a / 255)), line.c_str());
            window->DrawList->AddText(pFont, size, ImVec2((pos.x) + 1, (pos.y + textSize.y * i) - 1), ImGui::GetColorU32(ImVec4(0, 0, 0, a / 255)), line.c_str());
            window->DrawList->AddText(pFont, size, ImVec2((pos.x) - 1, (pos.y + textSize.y * i) + 1), ImGui::GetColorU32(ImVec4(0, 0, 0, a / 255)), line.c_str());

            window->DrawList->AddText(pFont, size, ImVec2(pos.x, pos.y + textSize.y * i), ImGui::GetColorU32(ImVec4(r / 255, g / 255, b / 255, a / 255)), line.c_str());
        }

        y = pos.y + textSize.y * (i + 1);
        i++;
    }

    return y;
}

void Renderer::DrawLine(const ImVec2& from, const ImVec2& to, uint32_t color, float thickness)
{
    ImGuiWindow* window = ImGui::GetCurrentWindow();

    float a = (color >> 24) & 0xff;
    float r = (color >> 16) & 0xff;
    float g = (color >> 8) & 0xff;
    float b = (color) & 0xff;

    window->DrawList->AddLine(from, to, ImGui::GetColorU32(ImVec4(r / 255, g / 255, b / 255, a / 255)), thickness);
}

void Renderer::DrawCircle(const ImVec2& position, float radius, uint32_t color, float thickness)
{
    ImGuiWindow* window = ImGui::GetCurrentWindow();

    float a = (color >> 24) & 0xff;
    float r = (color >> 16) & 0xff;
    float g = (color >> 8) & 0xff;
    float b = (color) & 0xff;

    window->DrawList->AddCircle(position, radius, ImGui::GetColorU32(ImVec4(r / 255, g / 255, b / 255, a / 255)), 12, thickness);
}

void Renderer::DrawCircleFilled(const ImVec2& position, float radius, uint32_t color)
{
    ImGuiWindow* window = ImGui::GetCurrentWindow();

    float a = (color >> 24) & 0xff;
    float r = (color >> 16) & 0xff;
    float g = (color >> 8) & 0xff;
    float b = (color) & 0xff;

    window->DrawList->AddCircleFilled(position, radius, ImGui::GetColorU32(ImVec4(r / 255, g / 255, b / 255, a / 255)), 12);
}

Renderer* Renderer::GetInstance()
{
    if (!m_pInstance)
        m_pInstance = new Renderer();

    return m_pInstance;
}