Bitwise operations

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- oosyrag
- - Joined 20 Feb, 2013
  - 61 topics • 4,744 posts
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- 23 Apr, 2017
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How is -1 (or any negative number) represented as a binary number in construct?

For the purposes of using setbit on unassigned tiles in a tilemap.
- R0J0hound
- - Joined 15 Jun, 2009
  - 90 topics • 7,301 posts
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- 23 Apr, 2017
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This is generally how the bits are for negative integer numbers.

https://en.m.wikipedia.org/wiki/Two%27s_complement
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- oosyrag
- - Joined 20 Feb, 2013
  - 61 topics • 4,744 posts
- 1
- 23 Apr, 2017
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Interesting, thanks! So -1 actually is supposed to be all 1s. I thought getbit wasn't working correctly with a negative number or something ><

I guess that means the last bit is reserved for determining a negative number or not, so an 8 bit number would range from -128 to 127 rather than 0 to 255.
- R0J0hound
- - Joined 15 Jun, 2009
  - 90 topics • 7,301 posts
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- 23 Apr, 2017
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Correct. Also keep in mind that typically numbers in javascript (or construct) are 64bit floating point numbers, but whenever a bitwise operation in done on them they are cast to a 32bit integer. So the number range is −2,147,483,648 to 2,147,483,647