[UPDATE] Add Section "Coding Style"

CONTRIBUTING.md

@@ -13,3 +13,187 @@ Your pull requests are welcome; however, they may not be accepted for various re
 In short: The easier the code review is, the better the chance your pull request will get accepted.
 
 
+##Coding style:
+
+####GENERAL
+
+* Do not use Java-like braces:
+
+GOOD:
+```c
+  if ()
+  {
+      // Do something
+  }
+```
+BAD:
+  ```c
+  if () {
+      // Do something
+  }
+```
+* Use tabs instead of whitespaces (we usually set our editors to 4
+  whitespaces for 1 tab, but the choice is up to you)
+
+
+* Always leave one space before and after binary and ternary operators
+  Only leave one space after semi-colons in "for" statements.
+
+GOOD:
+```c
+  if (10 == a && 42 == b)
+```
+BAD:
+  ```c
+  if (a==10&&b==42)
+```
+GOOD:
+  ```c
+  for (int i = 0; i != 10; ++i)
+  ```
+BAD:
+  ```c
+  for(int i=0;i<10;++i)
+```
+* Keywords are not function calls.
+  Function names are not separated from the first parenthesis:
+
+GOOD:
+```c
+    foo();
+    myObject.foo(24);
+```
+BAD:
+```c
+    foo ();
+```
+* Keywords are separated from the first parenthesis by one space :
+
+GOOD:
+```c
+    if (true)
+    while (true)
+```
+BAD:
+```c
+    if(myCondition)
+```
+
+* Use the following indenting for "switch" statements
+```c
+  switch (test)
+  {
+      case 1:
+	  {
+	      // Do something
+	      break;
+	  }
+	  default:
+	      // Do something else
+  } // No semi-colon here
+```
+
+* Avoid magic numbers
+
+BAD:
+```c
+  while (lifeTheUniverseAndEverything != 42)
+      lifeTheUniverseAndEverything =  buildMorePowerfulComputerForTheAnswer();
+```
+GOOD:
+```c
+  if (foo < I_CAN_PUSH_ON_THE_RED_BUTTON)
+      startThermoNuclearWar();
+```
+
+* Prefer enums for integer constants
+
+
+
+####NAMING CONVENTIONS
+
+* Classes (camel case) :
+
+GOOD:
+```c
+  class IAmAClass
+  {};
+```
+BAD:
+```c
+  class iAmClass
+  {};
+  class I_am_class
+  {};
+```
+
+* methods (camel case + begins with a lower case)
+  method parameters (camel case + begins with a lower case)
+
+GOOD:
+```c
+  void myMethod(uint myVeryLongParameter);
+```
+* member variables
+  Any member variable name of class/struct should be preceded by an underscore
+```c
+  public:
+      int _publicAttribute;
+  private:
+      int _pPrivateAttribute;
+      float _pAccount;
+```
+	  
+* Always prefer a variable name that describes what the variable is used for
+
+GOOD:
+```c
+  if (hours < 24 && minutes < 60 && seconds < 60)
+```
+BAD:
+```c
+  if (a < 24 && b < 60 && c < 60)
+```
+
+####COMMENTS
+
+* Use C++ comment line style than c comment style
+
+GOOD:
+```
+  // Two lines comment
+  // Use still C++ comment line style
+```
+BAD:
+```
+  /*
+  Please don't piss me off with that
+  */
+```
+
+
+####BEST PRACTICES
+
+* Prefer this form :
+```c
+      ++i
+```
+   to
+```c
+      i++
+```
+   (It does not change anything for builtin types but it would bring consistency)
+
+
+* Avoid using pointers. Prefer references. You might need the variable to
+  be assigned a NULL value: in this case the NULL value has semantics and must
+  be checked. Wherever possible, use a SmartPtr instead of old-school pointers.
+
+* Avoid using new if you can use automatic variable.
+
+* Don't place any "using namespace" directives in headers
+
+* Compile time is without incidence. Increasing compile time to reduce execution
+  time is encouraged.
+
+* Code legibility and length is less important than easy and fast end-user experience.