doytsujin / permafrost-engine

An OpenGL RTS game engine written in C

Permafrost Engine is an OpenGL 3.3 Real Time Strategy game engine written in C. It is made in the image of old classics, but incorporating some modern ideas.

Engine Showcase

EVERGLORY is the flagship game developed using Permafrost Engine.

Download the free (or donate what-you-want) demo on itch.io or on Steam. With the demo you also get access to all the scripts and assets powering the gameplay to learn from and modify as you wish.

Engine Summary

• OpenGL 3.3 programmable pipeline (more modern extensions used where available)
• Custom ASCII model format with Blender export script
• Skeletal animation with GPU skinning
• Phong reflection model with materials
• Directional light shadow mapping
• Batched rendering with dynamic batches
• Ringbuffer-based streaming of data to GPU
• RTS camera, FPS camera
• Rendering of tile-based map parsed from ASCII file
• Water rendering (including reflection, refraction, soft edge effects)
• Export/Import of game entites to/from ASCII files
• Engine internals exposed to Python 2.7 for scripting
• Event system
• UI framework (Nuklear-based)
• Efficient raycasting
• Map/Scene editor
• Pause/Resume system
• Fast rendering of huge maps
• Map navigation graph/grid generation
• Implementation of 'boids' steering/flocking behaviours
• Hierarchial flow field pathfinding
• Handling of dynamic obstacles in pathfinding
• Dynamic collision avoidance of multiple entities using Hybrid Reciprocal Velocity Obstacles and the ClearPath algorithm
• Pathfinding of different kinds/sizes of units (using "navigation layers")
• Efficient spatial indexing using a quadtree
• Efficient real-time tracking of entity membership to dynamic spatial regions
• Audio system supporting positional effects and multiple channels of global effects
• RTS minimap
• RTS-style unit selection
• RTS unit combat system
• RTS fog-of-war system
• RTS base-building mechanics
• RTS resource gathering (and transporting) mechanics
• Ranged combat using an efficient projectile physics simulation
• Support for different resolutions and aspect ratios
• Configurable graphics settings
• Serialization and deserialization of the entire Python interpreter state
• Saving and restoring of any engine session, including all Python-defined state
• Multithreaded: simulation and rendering in a 2-stage pipeline
• Advanced debug visualizations and profiling instrumentatation
• Fiber system for putting work in lightweight tasks that are scheduled in userspace
• Fiber-backed Python tasks, allowing cooperative multitasking logic in Python
• Cross-platform (Linux and Windows)
• Windows launcher to automatically capture a minidump and stdout, stderr logs on application error

Dependencies

• SDL2 2.0.10
• GLEW 2.1.0
• python 2.7.17
• openal-soft 1.21.1
• stb_image.h, stb_image_resize.h
• khash.h
• nuklear.h

All dependencies can be built from source and distributed along with the game binary if desired. Python is built with a subset of the default modules and packaged with a trimmed-down stdlib.

Building Permafrost Engine

For Linux

1. git clone https://github.com/eduard-permyakov/permafrost-engine.git
2. cd permafrost-engine
3. make deps (to build the shared library dependencies to ./lib)
4. make pf

Now you can invoke make run to launch the demo or make run_editor to launch the map editor. Optionally, invoke make launchers to create the ./demo and ./editor binaries which don't require any arguments.

For Windows

The source code can be built using the mingw-w64 cross-compilation toolchain (http://mingw-w64.org/doku.php) using largely the same steps as for Linux. Passing PLAT=WINDOWS to the make environment is the only required change.

The compliation can either be done on a Linux host, or natively on Windows using MSYS2 (https://www.msys2.org/).

1. git clone https://github.com/eduard-permyakov/permafrost-engine.git
2. cd permafrost-engine
3. make deps PLAT=WINDOWS
4. make pf PLAT=WINDOWS
5. make launchers PLAT=WINDOWS

License

Permafrost Engine is licensed under the GPLv3, with a special linking exception.

Devlog

Follow the development of Permafrost Engine and EVERGLORY on YouTube.

Indie RTS Devlog #1: Introducing Permafrost Engine

Indie RTS Devlog #2: Saving The Python Interpreter

Indie RTS Devlog #3: Group Pathfinding

EVERGLORY: Teaser Trailer #1

Indie RTS Devlog #4: Fog of War

Indie RTS Devlog #5: Performance Optimization

Indie RTS Devlog #6: Fibers, Async Jobs

Indie RTS Devlog #7: Main Menu UI, Loading Missions

Indie RTS Devlog #8: Python Tasks + Making Pong!

Indie RTS Devlog #9: Base Building

Indie RTS Devlog #10: Demo Gameplay

Indie RTS Devlog #11: Resource Gathering, Game Design

Indie RTS Devlog #12: Crafting Units

Indie RTS Devlog #13: Large Unit Pathfinding

Indie RTS Devlog #14: Projectiles, Big Battles

EVERGLORY - Official Trailer (2021 Indie RTS)

Comments/Questions

Comments or questions regarding the project or the source code? E-mail: [email protected]. Discuss EVERGLORY and its' development on Discord. If you have a useful fix for a non-trivial engine issue, feel free to make a PR. Be warned that I will scrutinize every patch to make sure it meets my personal quality standards for the engine code. It you wish to evelove the engine in some way and want the changes to be upstreamed, then do get in touch to discuss it.