Gamevar operators: Difference between revisions
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Helixhorned (talk | contribs) specify mod behavior with negative arguments, see further discussion on the discussion page. |
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|[[Wikipedia:Bitwise operation|bitwise]] AND | |[[Wikipedia:Bitwise operation|bitwise]] AND | ||
|The bits in the result are set only if they were set in both of the values being operated on. Ex. (all numbers are [[Wikipedia:Binary numeral system|base-2]]):<br/> | |The bits in the result are set only if they were set in both of the values being operated on. Ex. (all numbers are [[Wikipedia:Binary numeral system|base-2]]):<br/> | ||
01001010 AND | 01001010 AND 11110100 is 01000000 | ||
11110100 is | |||
01000000 | |||
|- | |- | ||
|or | |or | ||
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|[[Wikipedia:Bitwise operation|bitwise]] OR | |[[Wikipedia:Bitwise operation|bitwise]] OR | ||
|The bits in the result are set only if they were set in either of the values being operated on. Ex.:<br/> | |The bits in the result are set only if they were set in either of the values being operated on. Ex.:<br/> | ||
01001010 OR | 01001010 OR 11110100 is 11111110 | ||
11110100 is | |||
11111110 | |||
|- | |- | ||
|xor | |xor | ||
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|[[Wikipedia:Bitwise operation|bitwise]] XOR | |[[Wikipedia:Bitwise operation|bitwise]] XOR | ||
|The bits in the result are set if only one of the values being operated on has those bits set. Ex.:<br/> | |The bits in the result are set if only one of the values being operated on has those bits set. Ex.:<br/> | ||
01001010 XOR | 01001010 XOR 11110100 is 10111110 | ||
11110100 is | |||
10111110 | |||
|} | |} | ||
Revision as of 12:20, 8 March 2015
<operator>var <gamevar> <value>
<operator>varvar <gamevar> <value>
Gamevar operators are commands that perform various mathematical and bitwise logical operations on gamevars. The first argument must be a writable gamevar and is taken as the destination as well and the first operand (2-address code).
For example:
setvar temp 1 // assigns a value of 1 to the gamevar temp. addvar temp 1 // adds 1 to temp, causing its value to become 2. mulvar temp 2 // multiplies temp by 2, causing its value to become 4.
Operator | C/C++ | Math | Description | Notes | |
---|---|---|---|---|---|
set | =
|
= | assignment | ||
add | +
|
+ | addition | ||
sub | -
|
– | subtraction | ||
mul | *
|
× | multiplication | ||
div | /
|
÷ | division with rounding toward 0 for nonnegative dividends | Ensure that <value> does not equal 0 at any time. The rounding behavior is undefined for negative dividends. | |
mod | %
|
modulo, remainder | Ensure that <value> does not equal 0 at any time; sign of the result is that of left hand side operand (dividend). | ||
and | &
|
bitwise AND | The bits in the result are set only if they were set in both of the values being operated on. Ex. (all numbers are base-2): 01001010 AND 11110100 is 01000000 | ||
or | |
|
bitwise OR | The bits in the result are set only if they were set in either of the values being operated on. Ex.: 01001010 OR 11110100 is 11111110 | ||
xor | ^
|
bitwise XOR | The bits in the result are set if only one of the values being operated on has those bits set. Ex.: 01001010 XOR 11110100 is 10111110 |
Commands with an additional "var" suffix take gamevars rather than constants or defined labels for their inputs. As an alternate short form, "varvar" can be dropped from these commands; for example ife serves an an alias for ifvarvare.