isValid static method
Implementation
static bool isValid(AABB a) {
double dx = a.width;
double dy = a.height;
return dx >= 0 &&
dy >= 0 &&
// todo: does this handle -inf ?
a.left <= double.maxFinite &&
a.top <= double.maxFinite &&
a.right <= double.maxFinite &&
a.bottom <= double.maxFinite;
}