Disabled Player Sprite causes Flickering Dynamic Lights

[Pixel Eater]

When the player sprite is hidden, the player is at a perfect position/angle/pitch and there are flickering dynamic lights nearby then some walls will light up immensely.

It's hard to capture because it's so fast but I've managed to luck out:


These were from the same pause, nothing changes except the cvar.

And here is a video

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The player position is ( 3066.311, 2594.501, -219.001 ), angle is 357.814, floor height is -368.
The wall's angle is 30.70.

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Code: Select all

Log started: Fri Feb 22 15:56:15 2019

GZDoom version g3.7.2
M_LoadDefaults: Load system defaults.
/Users/Ness/Documents/GZDoom/Hacx.ipk3: Unable to find IWADINFO
File has been removed from the list of IWADs
W_Init: Init WADfiles.
 adding /private/var/folders/4d/213lbwgx4mg2xnz_b3pnb4rc0000gn/T/AppTranslocation/0E6B7A8C-223B-4434-ABAD-DCE70B07393C/d/GZDoom.app/Contents/MacOS/gzdoom.pk3, 635 lumps
 adding /private/var/folders/4d/213lbwgx4mg2xnz_b3pnb4rc0000gn/T/AppTranslocation/0E6B7A8C-223B-4434-ABAD-DCE70B07393C/d/GZDoom.app/Contents/MacOS/zd_extra.pk3, 132 lumps
 adding /Users/Ness/Documents/GZDoom/doom.wad, 2306 lumps
 adding /private/var/folders/4d/213lbwgx4mg2xnz_b3pnb4rc0000gn/T/AppTranslocation/0E6B7A8C-223B-4434-ABAD-DCE70B07393C/d/GZDoom.app/Contents/MacOS/lights.pk3, 6 lumps
I_Init: Setting up machine state.
CPU speed: 3193 MHz
CPU Vendor ID: GenuineIntel
  Name: Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz
  Family 6, Model 60, Stepping 3
  Features: SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 HyperThreading
I_InitSound: Initializing OpenAL
  Opened device CoreAudio Default
  EFX enabled
V_Init: allocate screen.
S_Init: Setting up sound.
ST_Init: Init startup screen.
Checking cmd-line parameters...
S_InitData: Load sound definitions.
G_ParseMapInfo: Load map definitions.
Texman.Init: Init texture manager.
ParseTeamInfo: Load team definitions.
LoadActors: Load actor definitions.
script parsing took 200.68 ms
R_Init: Init Doom refresh subsystem.
DecalLibrary: Load decals.
M_Init: Init menus.
P_Init: Init Playloop state.
ParseSBarInfo: Loading custom status bar definition.
D_CheckNetGame: Checking network game status.
player 1 of 1 (1 nodes)
GL_VENDOR: NVIDIA Corporation
GL_RENDERER: NVIDIA GeForce GT 755M OpenGL Engine
GL_VERSION: 4.1 NVIDIA-12.0.21 355.11.10.50.10.103 (Core profile)
GL_SHADING_LANGUAGE_VERSION: 4.10
GL_EXTENSIONS: GL_ARB_blend_func_extended GL_ARB_draw_buffers_blend GL_ARB_draw_indirect GL_ARB_ES2_compatibility GL_ARB_explicit_attrib_location GL_ARB_gpu_shader_fp64 GL_ARB_gpu_shader5 GL_ARB_instanced_arrays GL_ARB_internalformat_query GL_ARB_occlusion_query2 GL_ARB_sample_shading GL_ARB_sampler_objects GL_ARB_separate_shader_objects GL_ARB_shader_bit_encoding GL_ARB_shader_subroutine GL_ARB_shading_language_include GL_ARB_tessellation_shader GL_ARB_texture_buffer_object_rgb32 GL_ARB_texture_cube_map_array GL_ARB_texture_gather GL_ARB_texture_query_lod GL_ARB_texture_rgb10_a2ui GL_ARB_texture_storage GL_ARB_texture_swizzle GL_ARB_timer_query GL_ARB_transform_feedback2 GL_ARB_transform_feedback3 GL_ARB_vertex_attrib_64bit GL_ARB_vertex_type_2_10_10_10_rev GL_ARB_viewport_array GL_EXT_debug_label GL_EXT_debug_marker GL_EXT_depth_bounds_test GL_EXT_framebuffer_multisample_blit_scaled GL_EXT_texture_compression_s3tc GL_EXT_texture_filter_anisotropic GL_EXT_texture_mirror_clamp GL_EXT_texture_sRGB_decode GL_APPLE_client_storage GL_APPLE_container_object_shareable GL_APPLE_flush_render GL_APPLE_object_purgeable GL_APPLE_rgb_422 GL_APPLE_row_bytes GL_APPLE_texture_range GL_ATI_texture_mirror_once GL_NV_texture_barrier
Max. texture size: 16384
Max. texture units: 16
Max. varying: 16
Max. uniform block size: 65536
Uniform block alignment: 256
Resolution: 2560 x 1440

[Rachael]

Make sure to state your hardware and full information about the current version of your operating system. Posting your "About This Mac" screenshot should be sufficient for that purpose. A startup log from GZDoom may be helpful for diagnosing your system's specific OpenGL implementation, since Apple's tends to be kinda crappy. You can add "+logfile ~/Desktop/GZDoom-startup.txt" to GZDoom's command line options for this purpose.

[Pixel Eater]

Okay thanks, I've added those into the first post

[_mental_]

All this info is mostly useless without a map. In this case, a saved game is necessary too.

[Pixel Eater]

All this info is mostly useless without a map. In this case, a saved game is necessary too.

I somehow managed to find another angle where it flashes darker instead so there are two saves included.
Still it's weird that it only happens when the sprite is hidden

Google Drive

[_mental_]

Saved games must exactly match the map to be able to load them. That's what I've got with the provided sample

Code: Select all

This savegame needs these wads:
sladetemp_run.wad

[Pixel Eater]

Ran this one outside of a Slade sesh so it should be ok: Link

[_mental_]

While I still cannot comprehend what's exactly wrong with it, I managed to narrow it down to a particular case.
It happens when two consecutive calls to FLightBuffer::DoBindUBO() with different indices lead to the same offset.

For example, for the provided test it's enough to use index instead of offset in conjunction with mLastMappedIndex in the given function.
One extra call to glBindBufferRange() "fixes" the flickering. But it doesn't give a clue about the real cause of this bug.

[Graf Zahl]

Does this only happen on Macs? Your analysis shows why I haven't seen thids yet: It seems to be part of the GL3 renderpath.

[_mental_]

It’s GL3 render path but it’s not platform or hardware specific. Just force usage of UBO instead of SSBO and the bug will appear.
I tried to compare good and bad frames in RenderDoc. Uniforms are quite different and hard to compare directly. Like I said, good frames have an extra call to glBindBufferRange.

[_mental_]

I think I found the problem. If I got everything right, mLastMappedIndex must be invalidated in FLightBuffer::BindBase() function as well.
As it does glBindBufferBase() under the hood, offset in FLightBuffer::DoBindUBO() may point to a wrong uniform array element (without rebinding a proper range).

[Graf Zahl]

Yes, I think you are correct here

[_mental_]

Fixed in 087353f.