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Comment by SV_BubbleTime | Hacker News Reader

    wptr++;         /*  Skip number of sprites in frame */
    wptr++;         /*  Skip hotspot offset */

    wptr++;
    wptr++;

>Those last 2 pointer increments are skipping over data that goes completely unused, and it seems that at some point the data was removed from the ANM2FPA.EXE output.

Yea... I wouldn’t have found that so easily I don’t think. I don’t just increment pointers like that, and trying to determine intent of someone else’s code where there are just two random increments... this guy must be a lot sharper than me!

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He has the source code, I guess these comments are from original source code.

Oh I get that. My comment was still how easily this could be missed even with source.

Maybe it’s just me, but I rarely use ptr++ to jump over like that. I’m more likely to use ptr[1] that isn’t “destructive” to the location you started with.

It saves you needing a separate index variable. If you're doing something like LZSS decompression it makes the relative window offsets natural (absolute). Not sure I'd recommend coding like that today, unless ptr was a smart pointer that had bounds checking, but for the time period it was a perfectly fine technique.

But the destructive nature of ++wptr or whatever can be to its advantage, in that you never need to update any numbers when things change. The data is consumed/produced in the order specified, a property that is maintained even after new operations are inserted or existing operations are reordered.

(Whether you want this or not, who can say! - though I claim you typically do.)

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