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| author | Fedja Beader <fedja@protonmail.ch> | 2025-05-03 14:46:53 +0000 |
|---|---|---|
| committer | Jesusalva Jesusalva <jesusalva@tmw2.org> | 2025-05-03 14:46:53 +0000 |
| commit | 2805ee04adc7c20f5dc2a866ea1422d5dbc748d3 (patch) | |
| tree | 11fd143386b8e2c72dc34c958609b195ce3fc94b | |
| parent | df8cce5728bdf0a3155e6412a39cd7544570a1db (diff) | |
| download | serverdata-2805ee04adc7c20f5dc2a866ea1422d5dbc748d3.tar.gz serverdata-2805ee04adc7c20f5dc2a866ea1422d5dbc748d3.tar.bz2 serverdata-2805ee04adc7c20f5dc2a866ea1422d5dbc748d3.tar.xz serverdata-2805ee04adc7c20f5dc2a866ea1422d5dbc748d3.zip | |
Simplify base 2 logarithm computation
Could put shift into while loop condition, but this is more readable.
Untested, ofc...
* Add some testcases for log2, too
* Simplify base 2 logarithm computation
**** ml/serverdata!169
| -rw-r--r-- | npc/dev/test.txt | 5 | ||||
| -rw-r--r-- | npc/functions/math.txt | 32 |
2 files changed, 14 insertions, 23 deletions
diff --git a/npc/dev/test.txt b/npc/dev/test.txt index 268639102..b430dd57d 100644 --- a/npc/dev/test.txt +++ b/npc/dev/test.txt @@ -629,6 +629,11 @@ function script HerculesSelfTestHelper { callsub(OnCheck, "array shrink", .@x[1], 0); callsub(OnCheck, "array shrink and getarraysize", getarraysize(.@x), 0); + // log2 + callsub(OnCheck, "log2(0)", log2(0), -1); + callsub(OnCheck, "log2(1)", log2(1), 0); + callsub(OnCheck, "log2(3<<29)", log2(0x60000000), 30); + // min and max callsub(OnCheck, "min()", min(5, -10, 8, 3, -2, 1000), -10); callsub(OnCheck, "max()", max(5, -10, 8, 3, -2, 1000), 1000); diff --git a/npc/functions/math.txt b/npc/functions/math.txt index 22cf88159..d54558352 100644 --- a/npc/functions/math.txt +++ b/npc/functions/math.txt @@ -40,31 +40,17 @@ function script lognbaselvl { } // log2(<int>) -// returns the log base 2 of the passed integer, up to 20 (2**20=1.048.576) (round down always) - +// returns the base 2 logarithm of the passed integer +// Note: Negative values are first converted to positive. +// For 0, -1 is returned instead +// (as if passed value == 0.5, but that is not possible for integers). function script log2 { - .@v=abs(getarg(0)); - .@ok=0; - .@i=0; - if (.@v < 1) - return -1; - - freeloop(true); - while (!.@ok) { - // exact match - if (2**.@i == .@v) { - .@ok=1; - // inexact match, or limit exceeded - } else if (2**.@i >= .@v || .@i > 20) { - .@ok=1; - .@i-=1; // round down - // not yet - } else { - .@i+=1; - } + .@v = abs(getarg(0)); + .@i = -1; + while (.@v > 0) { + .@i += 1; + .@v >>= 1; } - freeloop(false); - return .@i; } |