game-engine

A place for me to experiment/build an entire game engine from scratch

Features

• PBR Rendering wth IBL(HDR Skyboxes)
• ECS using Data Oriented Design
• Scene Hierarchy Management
• Asset System
• FBX importing
• Logging
• Editor Integration with IMGUI
• Early Experimental Multi Threaded Job System

Editor features

• Scene Viewport for real time editing
• Game Viewport to see game run in editor
• Multi Viewports (Top, Side, Front Views)
• Inspector with all the component data
• Asset Browser with drag and drop
• Scene Hierarchy with drag and drop parenting
• Log with filtering
• Render System Data
• Game Loop/Engine timer Data
• Undo/Redo System

Libs

• zlib
• sdl
• imgui

Philosophy for writing this engine

• No libraries such as stl and boost. (No std::vector or std::string)
• Minimize dependencies
• Try to write everything from scratch as much as possible
• Program using Data Oriented Design
• Avoid OOP
• Program in C++, but avoid all the crazy modern C++ insanity
  • Templates are used sparingly (Only containers), also to avoid bloated compile times
  • Minimal use of operator overloading. Only used for Vectors, Matrices, and Quaternions
  • No Virtuals, Inheritance, or OOP-ness
  • No new/delete. Try to use custom memory allocators for everything
  • Avoid autos. Prefer fixed width int types (uint32_t/u32 over int)
  • No C++ Exceptions
  • No RTTI
  • Try to think hard about object lifetime and ownership.
• Avoid too many layers of abstraction
• Be explicit rather than implicit. Code is easier to follow in the debugger
• Think about the data and data flow
• Be wary about memory latency, memory layout, and the memory hierarchy
• Understand that you are writing code for a real machine with constraints, finite resources and not some abstract machine
  • How much memory does a system need?
  • How much time does a system need to perform its task?
  • Does this code need to be done now, or can it be done later?
• Write code that I need now and not in the future
• Write code that is easy to debug, understand, and easy to change
• Write code that can be multi-threaded easily
• Try to read the outputted assembly and try to understand what it is trying to do
• Understand that the compiler can't do everything

Future Goals

• Make the renderer agnostic
• Learn vulkan/dx12 for the renderer
• Rendering
  • Better lighting/shadows
  • Layered Materials
  • Particle System
  • Fog/Volumentric Lighting
  • Sub surface scattering
  • Post Processing
  • Ray tracing support
• Make everything multi threaded
• More hotloading
• Write/Intergrate a phsyics engine
• Write/Intergrate an animation system
• Better tooling/editor features
• Actually build a game with it.

Screenshots