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  1. Fast 16-bit ABS() in X86 Assembler

    I was reading a StackOverflow post on writing an absolute value function in assembler [1] and while the no-branching idea is exciting, I was sad that no 16-bit version was listed. The problem with converting the 32-bit assembler had to do with all of the crazy shifting, which is quite slow on the 8088 if you're doing more than a couple of bits in either direction. The no-branching concept is thus:

    Code:
    abs(x) = (x XOR y) - y
    Where y = 0xFFFF if x is negative and y = 0x0000 ...

    Updated June 5th, 2017 at 02:35 PM by neilobremski

    Tags: assembler, math Add / Edit Tags
    Categories
    Asm
  2. Radio Shack archives auction

    Wow, thanks for posting this info. Apparently the shipping could be an issue on some items and the 36 day to close is a little long.
    Things like the acoustic coupler will be interesting to follow.

    I am planning on going to the local store in about an hour for a "special event" this morning.
    Categories
    Uncategorized
  3. Complete Story of Lucasfilm Games & LucasArts | It's a Pixel THING - Special Episode

    1 hour and 22 minutes of video gaming history! Celebrating the 40th anniversary of Star Wars, here's the compilation of both It's a Pixel THING episodes about the Complete Story of Lucasfilm Games and LucasArts:

    Complete Story of Lucasfilm Games & LucasArts | It's a Pixel THING - Special Episode
  4. Simplifying Backface Culling

    The process of culling backfaces is simply checking the visibility of one-sided polygons based on whether they are facing towards the camera / player or away. If they are facing away then it is a back-facing side, rather than front-facing, and must be skipped during rendering. To determine this, I must calculate a normal vector. Every 3D triangle has two of these normals: one points outward from it and one points inward. The one you get depends on whether the calculation is made from vertices going ...

    Updated May 23rd, 2017 at 01:45 PM by neilobremski (Note about negating Ny)

    Tags: trigonometry Add / Edit Tags
    Categories
    3D
  5. Total Recall and the 2 Weeks Mystery | It's a Pixel THING - Ep. 118

    The home computer video game based on Total Recall suffered quite a harsh development process and, recently, the rolling demo of the original scrapped ZX Spectrum version was retrieved and made playable for us to try.
    Enjoy!

    Total Recall and the 2 Weeks Mystery | It's a Pixel THING - Ep. 118