File structure, naming, etc.

All classes should generally live in their own file, named ClassName.cpp.
For particularly large classes, major subsystems may be split up into their own files named ClassName_subsystem.cpp. For example, Foo_rendering.cpp and Foo_events.cpp.
Trivial helper classes/structures may be declared in the associated ClassName.h.
All headers should have include guards, with a macro named ClassName_h.
All files should begin with the project standard license header, then a Doxygen @file comment.

API Usage

Prefer use of logtools calls over raw printf() / std::cout for printing log messages with proper filtering etc.
Use new / delete for memory allocation rather than C-style malloc() / free().
All string functions that do not take an explicit buffer size argument are forbidden. This includes but is not limited to gets(), strcpy(), sprintf(), etc.
Use of C string manipulation functions with an explicit size, such as snprintf(), is acceptable.
Field width specifiers are required on all sscanf() calls that write to strings. For example, %30s rather than %s.

Use global variables only when there is no other practical way to accomplish the task.
Prefix all global variables with g_ to avoid namespace conflicts with local or member variables.

Use CamelCase naming without a leading C. For example, FoobarWindow, not CFoobarWindow or foobarWindow.
Internal implementation details should be protected to the extent practical to provide a clean API boundary.
Minimize use of private members in classes likely to be used as bases for other classes.
Prefix all member variables with m_ to avoid namespace conflicts with local or global variables.
Use CamelCase naming with an initial lowercase for member variables. For example m_sampleRateLabel.
When declaring user interface objects such as GTK elements, indent according to the UI element hierarchy.

One level of indentation = one \t character = four columns. Do not use spaces for indentation.
Curly braces go on their own line.
Curly braces are not required for a control statement with a single-line body, however if an explicitly empty body is used then use braces rather than simply a semicolon. The opening and closing braces may be on the same line.
The * in a pointer declaration is part of the type, not the variable. For example int* foo, not int *foo.
Do not put a space between a keyword or identifier name and an opening parentheses. For example if(foo), not if (foo).
If order of operations is not trivially obvious by inspection, add additional parentheses. Place spaces between multiple levels of parentheses. For example if( (foo == bar) || (baz == foobar) ).
astyle code formatting (for *.cpp) astyle -T --indent-switches --style=bsd --lineend=linux