Shade Engine

Built by: Utsav Lal and Jayesh Gajbhar
Library: SDL2, ZeroMQ, nlohmann/json and C++ 20

Introduction

The engine was started from the template shared by Dr. Alexander Card in moodle and grew from the same template. Current capabilities include:

1. A fully functional Entity Component System
2. Keyboard movement using WASD
3. Physics with customizable gravity in x and y directions
4. Collisions between objects with conservation of kinetic energy
5. A simple state machine animation controller
6. Fully multithreaded engine
7. Custom timeline class with ability to pause, play and increase decrease speed.
8. Asynchronous networking capabilities using ZMQ for client server and peer to peer between 3 clients.
9. A fully functional Event System where you can raise an event immediately or later or send it to the server.

Instructions to build the code

Since we used CLion CMake is required to build the project

PS: Remember to run the server first and then the clients

1. If there is an existing build folder run rm -r build to clear and remove the folder
2. Run mkdir build && cd build from the root to create a new build folder and change directory to it
3. Run cmake .. to generate required make files in build folder
4. Run make all to compile the binaries (this includes the game engine and game binaries)
5. Run ./shade_engine_server to start the server for the game engine
6. Run ./shade_engine to start the game engine or the game in this version

Please ensure that both the server and the game are started with the same messaging system.

PS: Another way to build the project would be to simply open it in CLion IDE and setting the env variables from the build menu.

Building the games

No further action is required for building the games. The engine and game are run from the same executable for this version.

Playing and Controls

1. Use AD to move the player
2. Use Space to jump
3. Use Shift + D to dash right or Shift + A to dash left

• If you fall down you will die and respawn after 5 seconds.
• If you land on a platform the character will get locked on it unless you move. This is a feature so that player doesn't fall off the platform when it moves.
• If you move towards the right of the screen the camera will pan ahead

Things included in the demo

1. Events: We have the following events in the game: EntityRespawn, EntityDeath, EntityCollided, EntityInput, EntityTriggered, MainCharCreated, PositionChanged, DashRight, DashLeft. There names are self-explanatory.
2. Delayed Events: EntityDeath is a delayed event. It is raised after 5 seconds of the player falling down.
3. Handlers: Inside systems/ files which end with handler are event handlers. They are responsible for handling the events. For example combo_event_handler is responsible for handling the DashRight and DashLeft events.
4. Networked Events: MainCharCreated and PositionChanged events are networked events
5. Chords: DashRight and DashLeft are input chord events. They are raised when the player presses Shift + D or Shift + A respectively.

Clean Up

To clean up

1. Run cd .. to come back to parent directory
2. Run rm -r build to remove build folder

Project Structure

• main.cpp: This is the main entry point to the code
• CMakeLists.cpp: This is the build file which helps run Cmake and build the project
• game/: contains the game code (if any) for the project
• lib/: This contains all the source code for the project.
  • core/: The core elements of the game engine like setting up screen, etc
  • data_structures/: The custom data structures for the engine
  • enum/: Contains all the enumerations for the game engine
  • ECS/: Contains the elements of the Entity Component System
  • EMS/: Contains the elements of the Event Management System
  • enum/: Contains all the enums used in the project
  • game/: This contains game specific code. One such is a GameManager which is a singleton containing variables shared between the engine
  • generic/: This contains generic classes which might be used by us in the future
  • helpers/: This contains helper functions like random, constants, etc
  • models/: This contains the models for the game engine like the Component and Data Model
  • server: This contains a file called worker.cpp which is the main worker for the server.
  • strategy/: All the classes for strategy pattern (in our case we use it for selecting messaging by JSON or array of vectors)
  • systems/: All the systems for the game engine like PhysicsSystem, CollisionSystem, etc. Systems that end with handler are event handlers.