Computing: Free Pascal Programming

Planetary orbits simulation.

Download PlanetaryOrbits desktop application (Windows 64bit) Download PlanetaryOrbits source code (Lazarus/Free Pascal)

Description: Physics application, simulating planetary orbits: the 9 planets of our solar system turning around the sun. The users can choose which planets to consider, what and how to draw and how fast to run the graphical animation.
The simulation, based on Newton's law of attraction, shows the following:
  1. The relative distance of the 9 planets of our solar system from the sun and to each other.
  2. The planets' orbit periods (time they make to accomplish a full revolution around the sun).
  3. The direction they move (Venus and Uranus turning in opposite direction of the other 7 planets).
  4. An indication of the different planets size.
Help about how to use the application is included, as well as technical info about this program, that is my first experience with Object Oriented Programming.

Change log:
Version 1.0 (June 2018): Original program
Version 1.1 (September 2021)
    - Pause button reset, when Stop is pressed correction
    - Code review, comment addition, help texts spellchecking

Free Pascal features: Pascal object oriented programming. Using timers and images' Left and Top properties to create graphical animations (movement of objects). Curve drawings using canvas. String grids.


Planetary orbits PC application: Simulation data table
Planetary orbits PC application: Graphical animation