MantisBT - Zandronum
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IDProjectCategoryView StatusDate SubmittedLast Update
0004482Zandronum[All Projects] Bugpublic2025-03-31 17:122025-10-31 16:27
ReporterIlyStr 
Assigned To 
PrioritynormalSeverityminorReproducibilityalways
StatusconfirmedResolutionbackport later 
PlatformASRock B550, AMD Ryzen 5 56 x64OSWindows 10 LTSC EnterpriseOS Version21H2 (19044.357)
Product Version4.0-beta 
Target VersionFixed in Version 
Summary0004482: Flicker dyn.light's radius chance is inverted (Relatively to GZDoom and UDB)
DescriptionIn GZDoom and UDB:
1 — Almost always radius №2
359 — Almost always radius №1

Zandronum:
1 — Almost always radius №1
359 — Almost always radius №2

Why? It's supposed to be easily solved here
'https://github.com/TorrSamaho/zandronum/blob/2ec1c262355a59762353dc9594d6f3c3b79fb508/src/gl/dynlights/a_dynlight.cpp#L267 [^]'
```
        m_currentIntensity = float(m_intensity[rnd >= (1.f-pct) * 255]);
```

or more accurately here
'https://github.com/TorrSamaho/zandronum/blob/2ec1c262355a59762353dc9594d6f3c3b79fb508/src/gl/dynlights/a_dynlight.cpp#L265 [^]'
```
        float pct = ANGLE_TO_FLOAT(360-angle)/360.f;
```
Steps To Reproduce
Additional InformationI have 16+ dyn. flicker lights on map with second radius 0 and angle 350

Max lights on in GZDoom:'https://imgur.com/emuYEjQ [^]'
Max lights on in Zandronum:'https://imgur.com/zWiYzT7 [^]'
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Issue History
Date ModifiedUsernameFieldChange
2025-03-31 17:12IlyStrNew Issue
2025-03-31 17:14IlyStrNote Added: 0024372
2025-03-31 17:17IlyStrNote Edited: 0024372bug_revision_view_page.php?bugnote_id=24372#r14520
2025-03-31 19:06IlyStrNote Added: 0024374
2025-10-31 16:27Ru5tK1ngNote Added: 0024609
2025-10-31 16:27Ru5tK1ngStatusnew => confirmed
2025-10-31 16:27Ru5tK1ngResolutionopen => backport later

Notes
(0024372)
IlyStr   
2025-03-31 17:14   
(edited on: 2025-03-31 17:17)
And yes, I know that git thread is just a duplicate of heptapod's stable thread
(0024374)
IlyStr   
2025-03-31 19:06   
In general, it's best to backport from GZDoom.

'https://github.com/ZDoom/gzdoom/blob/master/src/playsim/a_dynlight.cpp [^]'
```
    case FlickerLight:
    {
// float rnd = randLight(360); if FRandom in Za can process arguments
//or if Za's FRandom cannot do this
        float rnd = randLight % 360.f;
        m_currentRadius = float((rnd < ANGLE_TO_FLOAT(angle))? pArgs[LIGHT_INTENSITY] : pArgs[LIGHT_SECONDARY_INTENSITY]);
        break;
    }
```
(0024609)
Ru5tK1ng   
2025-10-31 16:27   
The way the flicker lights are handled was changed by GZDoom 2.2. So the issue will be resolved when Zandro's codebase upgrades to this version of GZ. Zan 4.0 will be GZ 2.2 and that version is dropping next after 3.3.