trying to understand openGL Swap Interval from SDL log.txt

log.txt

./ags --windowed  --log-stdout=+m:all --sdl-log=1
Adventure Game Studio v3.6 Interpreter
Copyright (c) 1999-2011 Chris Jones and 2011-2023 others
ACI version 3.6.0.44

Initializing backend libs
SDL Version: 2.24.1
Initializing game data
Looking for the game data.
 Cwd: /home/user/git/user/ags/cmake-build-release
 Path arg: 
Searching in (cwd): /home/user/git/user/ags/cmake-build-release
Searching for game data in: /home/user/git/user/ags/cmake-build-release
Found game data pak: /home/user/git/user/ags/cmake-build-release/futureflashback.ags
Located game data pak: /home/user/git/user/ags/cmake-build-release/futureflashback.ags
Opened game data file: game28.dta
Game data version: 50
Compiled with: 3.5.0.20
Startup directory: /home/user/git/user/ags/cmake-build-release
Data directory: /home/user/git/user/ags/cmake-build-release/
Setting up game configuration
Logging to warnings.log
Unable to init voice pack 'speech.vox', file not found or of unknown format.
Initializing TTF renderer
Initializing mouse: number of buttons reported is 3
Install timer
Initializing audio
Requested audio driver: default
Audio driver: pulseaudio
AudioCore: opened device "Default OpenAL playback device"
Supported sound decoders:
 - MIDI decoder, using a subset of TiMidity : MIDI,MID,
 - Play modules through ModPlug : 669,AMF,AMS,DBM,DMF,DSM,FAR,GDM,IT,MDL,MED,MOD,MT2,MTM,OKT,PTM,PSM,S3M,STM,ULT,UMX,XM,
 - MPEG-1 Audio Layer I-III : MP3,MP2,MP1,
 - Microsoft WAVE audio format : WAV,
 - Audio Interchange File Format : AIFF,AIF,
 - Sun/NeXT audio file format : AU,
 - Ogg Vorbis audio : OGG,
 - Creative Labs Voice format : VOC,
 - Raw audio : RAW,
 - Shorten-compressed audio data : SHN,
 - Free Lossless Audio Codec : FLAC,FLA,
Install exit handler
Initialize path finder library
Load game data
Game title: 'FutureFlashback'
Game uid (old format): `4812389`
Game guid: '{654c3450-ef91-4c81-a232-2c95fcafdb96}'
Game GUI version: 119
Requested script API: v3.5.0-final (7), compat level: v3.5.0-alpha (6)
Built library path: libagsblend.so
dlopen returned: libagsblend.so: cannot open shared object file: No such file or directory
Built library path: ./libagsblend.so
dlopen returned: ./libagsblend.so: cannot open shared object file: No such file or directory
Built library path: /home/user/git/user/ags/cmake-build-release/libagsblend.so
dlopen returned: /home/user/git/user/ags/cmake-build-release/libagsblend.so: cannot open shared object file: No such file or directory
Plugin 'agsblend' could not be loaded (expected 'libagsblend.so'), trying built-in plugins...
Build-in plugin 'agsblend' found and being used.
Built library path: libagsjoy.so
dlopen returned: libagsjoy.so: cannot open shared object file: No such file or directory
Built library path: ./libagsjoy.so
dlopen returned: ./libagsjoy.so: cannot open shared object file: No such file or directory
Built library path: /home/user/git/user/ags/cmake-build-release/libagsjoy.so
dlopen returned: /home/user/git/user/ags/cmake-build-release/libagsjoy.so: cannot open shared object file: No such file or directory
Plugin 'agsjoy' could not be loaded (expected 'libagsjoy.so'), trying built-in plugins...
Placeholder functions for the plugin 'agsjoy' found.
Checking for disk space
Initializing resolution settings
Game native resolution: 320 x 180 (32 bit)
Mouse cursor graphic area: (0,0)-(319,179) (320x180)
Device display resolution: 1920 x 1080
Graphic settings: driver: OGL, windowed: yes, screen size: 0 x 0, game scale: round
Using graphics factory: OGL
Created graphics driver: OpenGL
Supported gfx modes (32-bit): 
	1920x1080;1920x1080;1680x1050;1600x1024;1600x900;1600x900;1440x900;1440x810;
	1400x1050;1400x900;1368x768;1360x768;1280x1024;1280x960;1280x800;1280x800;
	1280x720;1280x720;1152x864;1024x768;1024x768;1024x576;1024x576;960x720;
	960x600;960x540;960x540;928x696;896x672;864x486;840x525;800x600;
	800x600;800x600;800x512;800x450;720x450;720x405;720x405;700x525;
	700x450;684x384;680x384;640x512;640x480;640x480;640x400;640x360;
	640x360;640x360;576x432;512x384;512x288;480x270;480x270;432x243;
	432x243;400x300;400x300;360x202;360x202;320x240;320x180;320x180;
	
Attempting to find nearest supported resolution for screen size 1920 x 1080 (32-bit) windowed
Maximal allowed window size: 1920 x 1080
Attempt to switch gfx mode to 1920 x 1080 (32-bit) windowed
Running OpenGL: 3.0
OGL: Transparency shader program created successfully
OGL: Tinting shader program created successfully
OGL: Lighting shader program created successfully
Graphics mode set: 1920 x 1080 (32-bit) windowed
Render frame set, render dest (0, 0, 1919, 1079 : 1920 x 1080)
Requested gfx filter: StdScale
Graphics filter set: 'StdScale', filter dest (0, 0, 1919, 1079 : 1920 x 1080)
Using gfx filter: StdScale
Mouse speed control: enabled, unit: 1.000000, user value: 1.000000
Touch-to-mouse motion mode: absolute
Mouse cursor graphic area: (0,0)-(1919,1079) (1920x1080)
Multitasking mode set: 0
Setting up window
Multitasking mode set: 0
Displaying preload image
Initialize sprites
Initialize game settings
Prepare to start game
Engine initialization complete
Starting game
Multitasking mode set: 1
Game.SetAudioTypeVolume: type: 1, volume: 70, change: all
Game.SetAudioTypeVolume: type: 2, volume: 70, change: all
Game.SetAudioTypeVolume: type: 3, volume: 70, change: all
OGL: SetVsyncImpl(1)
OGL: SetVsyncImpl result (success == 1)
Attempting to find nearest supported resolution for screen size 1920 x 1080 (32-bit) fullscreen
Attempt to switch gfx mode to 1920 x 1080 (32-bit) fullscreen
Graphics mode set: 1920 x 1080 (32-bit) fullscreen desktop
Render frame set, render dest (0, 0, 1919, 1079 : 1920 x 1080)
Mouse speed control: enabled, unit: 1.000000, user value: 1.000000
Touch-to-mouse motion mode: absolute
Mouse cursor graphic area: (0,0)-(1919,1079) (1920x1080)
Multitasking mode set: 1
Window event: focus lost
Switching out from the game
Window event: focus gained
Switching back into the game
Window event: focus lost
Switching out from the game
Window event: focus gained
Switching back into the game
Window event: focus lost
Switching out from the game