Complete implementation of the Object-Oriented Programming Piscine,
including all mandatory and bonus exercises.
The project progresses from core OOP principles to a complete railway
simulation engine with realistic physics, procedural world generation,
and hot reload support.
- Overview
- Project Structure
- Modules
- Module 05 --- Railway Simulation Engine
- Advanced Features
- Design Patterns
- Compilation
- Usage
- Documentation
This project is a comprehensive Object-Oriented Programming curriculum divided into 6 modules.
Core concepts covered:
- Encapsulation
- Object relationships
- UML modeling
- SOLID principles
- Design Patterns
- Simulation engine architecture
- Physics-based modeling
- Procedural world generation
- Deterministic simulation
- Hot reload architecture
opp-piscine/
├── module00/ # Encapsulation
│ ├── ex00/ # Banking system
│ └── ex01/ # Graph visualization
├── module01/ # Relationships
│ └── ex00/ # Worker-Tool-Workshop system
├── module02/ # UML Diagrams
│ └── ex00/ # Car system diagrams
├── module03/ # SOLID Principles
│ ├── ex00/ # [S]ingle Responsibility
│ ├── ex01/ # [O]pen/Closed
│ ├── ex02/ # [L]iskov Substitution
│ ├── ex03/ # [I]nterface Segregation
│ └── ex04/ # [D]ependency Inversion
├── module04/ # Design Patterns
│ ├── ex00/ # Preparation (base classes)
│ ├── ex01/ # Singleton
│ ├── ex02/ # Factory & Command
│ ├── ex03/ # Mediator
│ ├── ex04/ # Observer
│ └── ex05/ # Facade
└── module05/ # Railway Simulation
├── docs/ # Design/architecture documents
│ └── uml/ # UML diagrams
├── include/ # Header files
├── src/ # Source files
├── tests/ # Unit and integration tests
└── examples/ # Simulation input examples
Core features:
- Multi-train simulation
- Collision avoidance system
- Deterministic simulation
- Event-driven architecture
- Pathfinding system
- Procedural world generation
- Real-time rendering
- Hot reload support
- Replay recording and playback
- Monte Carlo analysis mode
- Round-trip train mode
The simulation includes a fully implemented physics engine that models realistic train movement based on physical properties and environmental constraints.
Key features:
- Realistic acceleration based on train mass and traction force
- Braking system that allows trains to slow down and stop smoothly at stations or when blocked
- Friction and resistance simulation affecting train speed over time
- Speed limits enforced per rail segment
- Continuous position and velocity updates during simulation
- State-dependent behavior (accelerating, cruising, braking, waiting, stopped)
- Deterministic timestep system ensuring consistent and reproducible results
The physics engine ensures that train movement behaves realistically while remaining stable, deterministic, and suitable for real-time simulation.
The simulation includes a procedural world generation system used to create dynamic and non-repetitive environments for rendering.
Key features:
- Biomes generated based on temperature distribution across the map
- Terrain refinement using neighborhood analysis for smoother transitions
- Deterministic generation using a seed, ensuring reproducible worlds
- Fully dynamic terrain creation without requiring predefined maps
This system allows the simulation to render unique environments while remaining consistent and predictable.
The project includes a real-time rendering engine built using SFML, responsible for visualizing the simulation and interacting with the generated world.
Key features:
- Real-time visualization of train movement across the railway network
- Integration with the procedural terrain generation system
- Camera system with full user input support for navigation
- Smooth zoom in and zoom out using linear interpolation for stable visual transitions
- Input handling for camera movement and simulation interaction
- Clear graphical representation of the simulation state and environment
The rendering engine is fully decoupled from the simulation logic, ensuring modularity, maintainability, and clean separation between visualization and core simulation systems.
The hot reload system allows simulation data to be reloaded at runtime without restarting the program.
Key features:
- Detects and reloads updated network or train configuration files
- Applies changes safely without breaking the current simulation
- Enables faster testing and iteration during development
- Reduces downtime when adjusting simulation parameters
This significantly improves development workflow and debugging efficiency.
The simulation uses an event-driven architecture to allow dynamic interaction between system components.
Key features:
- Centralized EventManager responsible for event distribution
- Trains and rails subscribe to events and react accordingly
- Enables dynamic changes during simulation
- Decouples systems for better modularity and extensibility
This architecture ensures flexible and scalable system behavior.
Additional features implemented after the core simulator:
- Replay system (Command pattern): record simulation commands with
--recordand replay with--replay=<file>. - Monte Carlo analysis: run repeated deterministic simulations using
--monte-carlo=Nfor statistical validation. - Round-trip mode: trains automatically reverse direction at destination with
--round-trip. - Pathfinding switch: choose algorithm at runtime with
--pathfinding=dijkstra|astar.
The project makes extensive use of established software design patterns to ensure clean architecture and extensibility.
Implemented patterns:
- Factory Pattern for controlled object creation
- State Pattern for managing train behavior
- Strategy Pattern for pathfinding algorithms
- Observer Pattern for event handling
- Command Pattern for runtime operations such as hot reload
- Singleton Pattern for centralized simulation management
These patterns improve modularity, maintainability, and scalability of the simulation engine.
c++ -Wall -Wextra -Werror
make
cd module05
make
./railway_sim examples/network_simple.txt examples/trains_simple.txt
Hot reload:
./railway_sim examples/network_simple.txt examples/trains_simple.txt --hot-reload
Replay record / replay:
./railway_sim examples/network_simple.txt examples/trains_simple.txt --record ./railway_sim examples/network_simple.txt examples/trains_simple.txt --replay=output/replay.json
Monte Carlo:
./railway_sim examples/network_simple.txt examples/trains_simple.txt --monte-carlo=100
module05/docs/
- Simulation engine architecture
- Procedural generation
- Physics simulation
- Design patterns
- Hot reload system
- Replay recording and playback
- Monte Carlo analysis mode