legs/examples/02_systems/main.cpp

#include <memory>

#include <legs/entry.hpp>

#include <legs/entity/mesh_entity.hpp>
#include <legs/entity/sky.hpp>
#include <legs/geometry/icosphere.hpp>
#include <legs/geometry/plane.hpp>
#include <legs/isystem.hpp>
#include <legs/log.hpp>
#include <legs/time.hpp>

using namespace legs;

class MySystem : public ISystem
{
  public:
    MySystem()
    {
        int width;
        int height;
        g_engine->GetWindow()->GetFramebufferSize(&width, &height);
        m_camera = std::make_shared<NoclipCamera>(width, height);
        m_camera->SetPosition({0.0f, -10.0f, 5.0f});
        g_engine->SetCamera(m_camera);

        auto renderer = g_engine->GetRenderer();
        auto world    = g_engine->GetWorld();

        // Create a sky
        auto sky = std::make_shared<Sky>(renderer);
        world->SetSky(sky);

        // Create some test spheres
        for (unsigned int x = 0; x < 3; x++)
        {
            for (unsigned int y = 0; y < 3; y++)
            {
                auto                    testSphere = SIcosphere(glm::vec3(x, y, 5), 0.5f, 1);
                std::shared_ptr<Buffer> sphereVertexBuffer;
                std::shared_ptr<Buffer> sphereIndexBuffer;

                std::vector<Vertex_P_N_C> sphereVertices;
                sphereVertices.reserve(testSphere.positions.size());
                for (unsigned int i = 0; i < testSphere.positions.size(); i++)
                {
                    sphereVertices.push_back(
                        {testSphere.positions[i], testSphere.normals[i], glm::vec3(0.5, 0.5, 0.5)}
                    );
                }
                renderer->CreateBuffer(
                    sphereVertexBuffer,
                    VertexBuffer,
                    sphereVertices.data(),
                    sizeof(Vertex_P_N_C),
                    static_cast<uint32_t>(sphereVertices.size())
                );
                renderer->CreateBuffer(
                    sphereIndexBuffer,
                    IndexBuffer,
                    testSphere.indices.data(),
                    sizeof(Index),
                    static_cast<uint32_t>(testSphere.indices.size())
                );

                auto sphere = std::make_shared<MeshEntity>();
                sphere->SetBuffers(sphereVertexBuffer, sphereIndexBuffer);
                sphere->SetPipeline(RenderPipeline::GEO_P_N_C);
                world->AddEntity(sphere);
                m_spheres.push_back(sphere);
            }
        }

        // Create a test plane
        std::shared_ptr<Buffer> planeVertexBuffer;
        std::shared_ptr<Buffer> planeIndexBuffer;

        auto testPlane     = SPlane({0.0f, 0.0f, 0.0f}, 20.0f);
        auto planeVertices = std::array<Vertex_P_C, 4>();
        for (unsigned int i = 0; i < 4; i++)
        {
            auto color = glm::vec3 {
                i == 0 ? 1.0f : 0.0f,
                i == 1 ? 1.0f : 0.0f,
                i == 2 ? 1.0f : 0.0f,
            };
            planeVertices[i] = {testPlane.vertices[i], color};
        }
        renderer->CreateBuffer(
            planeVertexBuffer,
            VertexBuffer,
            planeVertices.data(),
            sizeof(Vertex_P_C),
            static_cast<uint32_t>(planeVertices.size())
        );
        renderer->CreateBuffer(
            planeIndexBuffer,
            IndexBuffer,
            testPlane.indices.data(),
            sizeof(Index),
            static_cast<uint32_t>(testPlane.indices.size())
        );

        auto plane = std::make_shared<MeshEntity>();
        plane->SetBuffers(planeVertexBuffer, planeIndexBuffer);
        plane->SetPipeline(RenderPipeline::GEO_P_C);
        world->AddEntity(plane);
    }

    ~MySystem()
    {
    }

    void OnFrame() override
    {
        m_camera->HandleInput(g_engine->GetFrameInput());

        // TODO: model matrix buffer
        // Move the spheres around
        /*
        for (unsigned int i = 0; i < m_spheres.size(); i++)
        {
            auto pos = m_spheres[i]->GetPosition();
            pos.z    = static_cast<float>(std::sin(legs::Time::Uptime() * i));
            m_spheres[i]->SetPosition(pos);
        }
        */

        // Move the sun across the sky
        const auto degreesPerSecond = 5.0;
        auto       sunRotation      = glm::angleAxis(
            glm::radians(degreesPerSecond * legs::Time::Uptime()),
            glm::normalize(glm::dvec3 {1.0, 0.3, 0.2})
        );
        g_engine->GetWorld()->GetSky()->SunDirection =
            glm::normalize(sunRotation * glm::dvec3(0.1, 0.2, 1.0));
    }

    void OnTick() override
    {
    }

  private:
    std::shared_ptr<NoclipCamera>            m_camera;
    std::vector<std::shared_ptr<MeshEntity>> m_spheres;
};

int main(int argc, char** argv)
{
    Log::SetLogLevel(LogLevel::Debug);

    auto code = LEGS_Init(argc, argv);
    if (code < 0)
    {
        return code;
    }

    g_engine->GetWindow()->SetTitle("02_systems");

    g_engine->AddSystem(std::make_shared<MySystem>());

    return LEGS_Run();
}