README.md

OSRE - Just another Open Source Render Engine

This is just another open-source render engine / game engine made by Kim Kulling. This is a playground project for me to work on my side projects. Don't expect too much, I will not invest too much time into it. But If you are interested in playing around with 3D stuff feel free to discuss these things on Reggit or in the Discussion Forum.

The Features:

• CMake base build environment
• Multithreaded Renderer
  • OpenGL
• Platform abstraction to support Windows, Linux, and more.
  • Input
  • UI
• Component-based entity system
  • Transformation components
  • Render components
• Event-System
  • Event bus
• More than 40 3D formats supported thanks to Assimp
• Virtual file system for reading zip-archives
• Instancing

Build Status

Documentation

• Please check OSRE-Docs.

Project activities

Join out community

We have a discord server at Discord

Build instructions

• See Build instruction in the Wiki

Questions

• Take a look into our OSRE-Forum
• Please check our Reddit-Community

Supported compilers

• Windows:
  • Visual Studio 2019
  • Visual Studio 2022
• Linux:
  • GCC
  • Clang

Quick Start

#include <osre/App/App.h>
#include <osre/Common/Logger.h>
#include <osre/RenderBackend/RenderBackendService.h>
#include <osre/Scene/MeshBuilder.h>
#include <osre/Scene/Camera.h>
#include <osre/Platform/AbstractWindow.h>
#include <osre/RenderBackend/glm_common.h>

using namespace ::OSRE;
using namespace ::OSRE::App;
using namespace ::OSRE::RenderBackend;

class QuickStartApp : public AppBase {
    /// The transform block, contains the model-, view- and projection-matrix
    TransformMatrixBlock m_transformMatrix;
    /// The entity to render
    Entity *mEntity;

public:
    /// The class constructor with the incoming arguments from the command line.
    QuickStartApp(int argc, char *argv[]) :
            AppBase(argc, (const char **)argv),
            m_transformMatrix(),
            mEntity(nullptr) {
        // empty
    }

    /// The class destructor, default impl.
    ~QuickStartApp() override = default;

protected:
    /// The creation callback, will get called on system startup.
    bool onCreate() override {
        if (!AppBase::onCreate()) {
            return false;
        }

        // The window
        AppBase::setWindowsTitle("Quickstart! Rotate with wasd, scroll with qe");
        
        // The world to work in
        World *world = getActiveWorld();
        
        // The entity for your triangle
        mEntity = new Entity("entity", *AppBase::getIdContainer(), world);
        
        // The camera to watch the scene
        Scene::Camera *camera = world->addCamera("camera_1");
        ui32 w, h;
        AppBase::getResolution(w, h);        
        camera->setProjectionParameters(60.f, (f32)w, (f32)h, 0.001f, 1000.f);

        // Create and add the triangle 
        Scene::MeshBuilder meshBuilder;
        RenderBackend::Mesh *mesh = meshBuilder.allocTriangles(VertexType::ColorVertex, BufferAccessType::ReadOnly).getMesh();
        if (nullptr != mesh) {
            mEntity->addStaticMesh(mesh);
            world->addEntity(mEntity);            
            
            // And observer the triangle
            camera->observeBoundingBox(mEntity->getAABB());
        }

        return true;
    }

    /// The update, will be called for each render frame
    void onUpdate() override {
        glm::mat4 rot(1.0);
        if (AppBase::isKeyPressed(Platform::KEY_A)) {
            m_transformMatrix.m_model *= glm::rotate(rot, 0.01f, glm::vec3(1, 0, 0));
        }
        if (AppBase::isKeyPressed(Platform::KEY_D)) {
            m_transformMatrix.m_model *= glm::rotate(rot, -0.01f, glm::vec3(1, 0, 0));
        }

        if (AppBase::isKeyPressed(Platform::KEY_W)) {
            m_transformMatrix.m_model *= glm::rotate(rot, 0.01f, glm::vec3(0, 1, 0));
        }

        if (AppBase::isKeyPressed(Platform::KEY_S)) {
            m_transformMatrix.m_model *= glm::rotate(rot, -0.01f, glm::vec3(0, 1, 0));
        }

        if (AppBase::isKeyPressed(Platform::KEY_Q)) {
            m_transformMatrix.m_model *= glm::scale(rot, glm::vec3(1.01f, 1.01, 1.01f));
        }

        if (AppBase::isKeyPressed(Platform::KEY_E)) {
            m_transformMatrix.m_model *= glm::scale(rot, glm::vec3(0.99f, 0.99f, 0.99f));
        }

        // Set the model-matrix in the renderpass
        RenderBackendService *rbSrv = getRenderBackendService();

        rbSrv->beginPass(PipelinePass::getPassNameById(RenderPassId));
        rbSrv->beginRenderBatch("b1");

        rbSrv->setMatrix(MatrixType::Model, m_transformMatrix.m_model);

        rbSrv->endRenderBatch();
        rbSrv->endPass();

        AppBase::onUpdate();
    }
};

OSRE_MAIN(QuickStartdApp)

OSRE-Ed

The engine provdes an 3D-Editor called OSRE-Ed. It is still experimental: