>> Yes and yes. They are ugly, and I wonder whether I should drop the
>> `OVERFLOW_' part of its names to get `SUB_LONG', `ADD_INT32', etc.
>
> Please drop OVERFLOW.
OK.
> I see them as a red flag to rethink the code.
I disagree, at least partially, since...
> The add and sub overflows should not be happening on 32 bits because
> we limit ourselves to 1Gb bitmaps aka 32768x32768. Even at 1/256
> pixel resolution there is plenty of space to avoid overflows.
... rendering is probably the *only* part in FreeType where your
assumption is correct, because we work with absolute point coordinates
in an FT_Outline structure. However, within fonts, almost everything
is stored as coordinate deltas; this means that malformed fonts can
create arbitrarily large values very easily. Ditto for bytecode.
Checking every addition, subtraction or multiplication for overflow is
something I want to avoid, so we have to tag all operations where
overflow can occur.
Werner
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