WebGL context lost error on iOS

[Vadim-Karpenko]

Client:

Device: iPhone X
iOS version: 16.1.2
Browser: Safari

Server

For development purposes, I'm using a localhost windows 10 machine and Nginx server served via Ngrok.
Renpy version: 8.1.0.22112903n (nightly build)
I did set 1920x804 resolution in my RenPy project, I don't think this can be the cause of the error, but it is worth mentioning.

Steps to reproduce

Here's the code that is causing an error:

centered "Some text" with pixellate

centered "Some text 2" with pixellate

centered "Some text 3" with pixellate
menu:
    "Next":
        jump some_other_label
    "Exit":
        $ renpy.quit()

My guess is that menu is causing an issue. Whenever it's about to appear, an error WebGL context lost. Please reload the page showing up.

Renpy logs

Thu Dec  1 13:26:10 2022
Emscripten-3.1.24-wasm32-32bit
Ren'Py 8.1.0.22112903n
 

Bootstrap to the start of init.init took 0.00s
Early init took 0.01s
Loader init took 0.02s
Loading error handling took 0.16s

Loading script...
Loading script took 3.82s
Loading save slot metadata. took 0.01s
Loading persistent took 0.00s
Faled to initialize steam: ModuleNotFoundError("No module named '_ctypes'")
Set script version to: (8, 1, 0)
Running init code took 0.18s
Loading analysis data took 0.04s
Analyze and compile ATL took 0.01s
Index archives took 0.00s
Dump and make backups. took 0.00s
Cleaning cache took 0.01s
Making clean stores took 0.01s
Initial gc. took 0.06s
DPI scale factor: 1.000000
Creating interface object took 0.01s
Cleaning stores took 0.00s
Init translation took 0.12s
Build styles took 0.02s
Load screen analysis took 0.00s
Analyze screens took 0.03s
Save screen analysis took 0.15s
Prepare screens took 0.18s
Save pyanalysis. took 0.00s
Save bytecode. took 0.09s
Running _start took 0.01s
Interface start took 0.19s

Initializing gles2 renderer:
primary display bounds: (0, 0, 375, 812)
swap interval: 1 frames
Windowed mode.
UGUU couldn't find b'glFlushMappedBufferRange': b'No OpenGL context has been made current'
UGUU couldn't find b'glGetBufferPointerv': b'No OpenGL context has been made current'
UGUU couldn't find b'glMapBufferRange': b'No OpenGL context has been made current'
UGUU couldn't find b'glUnmapBuffer': b'No OpenGL context has been made current'
Vendor: "b'WebKit'"
Renderer: b'WebKit WebGL'
Version: b'OpenGL ES 3.0 (WebGL 2.0)'
Display Info: None
Screen sizes: virtual=(1920, 804) physical=(375, 768) drawable=(1125, 2304)
Maximum texture size: 4096x4096
Screen sizes: virtual=(1920, 804) physical=(287, 768) drawable=(861, 2304)
Maximum texture size: 4096x4096
Screen sizes: virtual=(1920, 804) physical=(724, 375) drawable=(2172, 1125)
Maximum texture size: 4096x4096
Flip failed error(b'unable to show color buffer in an OS-native window (call to eglSwapBuffers failed, reporting an error of EGL_CONTEXT_LOST)')
Screen sizes: virtual=(1920, 804) physical=(724, 375) drawable=(2172, 1125)
Maximum texture size: 4096x4096