I am reading some code and can't identify what part of C++ this idiom is (that :fgl(NULL) that's in red below by the image::image definition).
If somebody can give me the magic phrase that I can look up (like "polymorphic initializer resolution") or whatever it's called, I'd appreciate that.
// initialised by init_fast_access() :
// allways initialised :
// initialised by analyse():
// initialised by Ceil()&analyse():
image(image *im,double scaleX,double scaleY);
void initFrom(image *im);
image(image *im, double ratio);
image(WORD _Width,WORD _Height,BYTE c);
image(imageD *im,BYTE s);
image::image(image *im, double ratio) : fgl(NULL)
// attention !!! before using this function, you must initialize
// the two variables gravityW and gravityH by calling analyse();