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rounding [2019/04/18 21:43] – korshunrounding [2019/08/26 21:02] (current) – korshun
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-===== Rounding functions =====+====== Rounding====== 
 + 
 +===== Introduction =====
  
 ACSUtils provides a full set of functions to round fixed-point numbers to integers. ACSUtils provides a full set of functions to round fixed-point numbers to integers.
 +
 +<note warning>Current GZDoom provides built-in functions [[zdoom>Floor_(ACS_function)|floor]], [[zdoom>ceil]] and [[zdoom>round]], but these functions aren't available in Zandronum 3.0 and **silently return 0** there, because all unimplemented built-in ACS functions return 0.
 +
 +Before using ACSUtils, rename either the built-in functions (by editing ''zspecial.acs'') or the ACSUtils functions (by editing ''acsutils.acs'') to something else. Otherwise, ACSUtils won't compile.
 +</note>
 +
 +===== Rounding modes =====
  
 There are four rounding modes: There are four rounding modes:
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   * ''round'' -- rounds the number to the closest integer   * ''round'' -- rounds the number to the closest integer
  
-Example rounding table:+A table that demonstrates the differences between rounding modes:
  
 ^  x   ^ round(x) ^ floor(x) ^ ceil(x) ^ trunc(x) ^ ^  x   ^ round(x) ^ floor(x) ^ ceil(x) ^ trunc(x) ^
 ^   1.3|         1|         1|        2|         1| ^   1.3|         1|         1|        2|         1|
-^   1.5|         2|         1|        2|         1|+^   1.5|    1 or 2|         1|        2|         1|
 ^   1.8|         2|         1|        2|         1| ^   1.8|         2|         1|        2|         1|
 ^  -1.3|        -1|        -2|       -1|        -1| ^  -1.3|        -1|        -2|       -1|        -1|
-^  -1.5|        -1|        -2|       -1|        -1|+^  -1.5|  -2 or -1|        -2|       -1|        -1|
 ^  -1.8|        -2|        -2|       -1|        -1| ^  -1.8|        -2|        -2|       -1|        -1|
  
-Every rounding mode is available as two functions. The ones with the ''i'' prefix in the name return an integer, while the ones without return a fixed-point number:+===== Functions =====
  
-^ Mode  ^ as fixed ^ as int ^ +Every rounding mode is available as two functions: 
-^ floor | ''floor()'' | ''ifloor()'' | +  * Functions without the ''i'' prefix return a fixed, e.g. ''floor(2.3) == 2.0''. 
-^ ceil  | ''ceil()'' | ''iceil()'' | +  * Functions with the ''i'' prefix return an int, e.g. ''ifloor(2.3) == 2''.
-^ round | ''round()'' | ''iround()'' | +
-^ trunc | ''trunc()'' | ''itrunc()'' |+
  
-Example of the difference between ''i'' and non-''i'' functions:+^ Mode  ^ fixed result ^ int result ^ 
 +^ floor | ''fixed floor(fixed x)'' | ''int ifloor(fixed x)'' | 
 +^ ceil  | ''fixed ceil(fixed x)''  | ''int iceil(fixed x)''  | 
 +^ round | ''fixed round(fixed x)'' | ''int iround(fixed x)'' | 
 +^ trunc | ''fixed trunc(fixed x)'' | ''int itrunc(fixed x)'' |
  
-  * ''floor(2.3) == 2.0;'' 
-  * ''ifloor(2.3) == 2;'' 
  
-So the full function list is as follows: 
  
-  * ''fixed floor(fixed x)'' 
-  * ''fixed ceil(fixed x)'' 
-  * ''fixed round(fixed x)'' 
-  * ''fixed trunc(fixed x)'' 
-  * ''int ifloor(fixed x)'' 
-  * ''int iceil(fixed x)'' 
-  * ''int iround(fixed x)'' 
-  * ''int itrunc(fixed x)'' 
rounding.1555613029.txt.gz · Last modified: 2019/04/18 21:43 by korshun

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