Programming project

Semester II, Physics session

Introduction:

The purpose of this project is to learn how to
symulate a physical system and, eventually, implement
it using a 3D graphical engine.

The programming language used is the C++.
A graphical representation is written
using the OpenGL engine powered by a Qt window manager.

Members: Raffaele Ancarola, Armando Cincotti

Goals:

I) Numerical symulation of a simple system (ex. a pendule)

II) Describing a more complex system (ex. damped harmonic oscillator)

III) The symulation of a particle system (always numerically)

IV) Graphics setup (Qt and OpenGL)

V) The transposition of older symulations into a graphical representation

Structure and organization:

symkit:

    The core of the project.
    A library which contains all the components needed in order
    to build any symulation in the simplest way.
    Here all low level calls, OpenGL functions and basic mechanics
    are implemented and all functionalities 
    are accessible as an object oriented engine.

test:

    The part of the project where symkit is used in order to 
    numerically symulate a physical system.

qtproject:

    A Qt project where  ....

Coding rules:

• The content of a .h file must be bound by a #ifndef MACRO block in order to prevent compilation conflicts, for example:
  
  #ifndef MYFILE_H #define MYFILE_H
  
  /* My content */
  
  class MyClass { /* Class content */ };
  
  #endif // MYFILE_H
• Class names must begin with a capitalized letter, for example:
  
  class MyClass { /* Class content */ };
• Namespace, structure, variable and function names must NOT begin with a capitalized letter, for example:
  
  void eraseAll();
  
  int foo = 0; double _time;
  
  struct boundingBox { /* Struct content */ };
• Warning!
  
  Few and well structured classes is better than a lot and small ones. Which means that inheritance is powerful and, for this reason, it is easy to abuse too.
  • Reminder of Chappelier: Never, NEVER copy-paste implementation code Use functions, classes, inheritance, pointers instead
  • Keep strict order in your code Remember that your partner have to be able to fully understant your code, so there are some tips:
    • TAB INDENT SET TO 4 SPACE CHARACTERS
      
      Your partner could use a different editor than yours, so taking fixed the Tab indent size to "4 space characters" is good in order to read the same text in the same vision
    • EXPLAIN WHAT YOU ARE DOING
      
      C++ allows you to comment your code. In some complex situations understanding a plain code could be much complicated for other people. Another reason to comment your code is that it speeds up debugging. Sometimes making an important change to the code could cause confusion onto other parts of the code, so commenting your code is useful to find faster an error and fix it better.
      
      For example:
      
      /* Set the delta time */ void set_dt(const float&);
      
      extern int error; // global error code
    • MAKE NAMES NOT TOO LONG
      
      Avoid very long names. Even if more comprehensible, use shorter names and eventually comment to explain them.
    • INDENTATION IS IMPORTANT
      
      Indentation style if free, but it must be fixed, ordered and logical.
      
      Some examples to write the same thing:
      • KEYWORDS USAGE
        
        float hello(const int& entry);
        
        float hello (int const& entry);
      • LOOPS
        
        for (int i = 0; i < 100; ++i) { /* Content */ }
        
        for (int i = 0; i < 100; ++i) {
        
        /* Content */ }
        
        int i; for (i = 0; i <= 99; ++i) {
        
        /* Content */ }
      • CONDITIONALS (4 spaces indent template)
        
        if (s == "hello") {
        
        s = "_hello_";
        
        } else if (s == "_hello")
        
        s += "_";
        
        } else {
        
        s = "_none_"; }
      • NESTING (4 spaces indent template)
        
        if (enable) { for (auto obj : objects) { if (obj == 0) continue; else return obj; } }