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Terminal: WebGL renderer corrupts glyph-atlas cells (solid black boxes) on ANGLE GLES backend (Mesa radeonsi); Vulkan & software backends fine #321007
Description
Type: Bug
With the WebGL terminal renderer (terminal.integrated.gpuAcceleration = auto/on), individual glyph cells render as solid black rectangles instead of the glyph. Affected cells are scattered and independent of foreground color and font weight — bold, non-bold, plain, and colored cells are all hit, and the same letter can box out in one weight while rendering fine in another. The boxes are solid/filled (not hollow tofu), consistent with corruption of individual cells in the renderer's glyph texture atlas. Most visible in glyph-dense full-screen TUIs like fzf.
Steps to reproduce
"terminal.integrated.gpuAcceleration": "auto"(or"on").- In the integrated terminal, run a glyph-dense fuzzy finder:
ls /usr/bin | fzf- Type to filter and scroll the list (forces glyphs into the atlas and triggers rapid redraws).
- Scattered glyph cells render as solid black boxes. (Screenshots attached.)
Bisection
| Configuration | Result |
|---|---|
gpuAcceleration: off (DOM renderer) |
correct |
| External terminal (Ghostty), same font/machine | correct |
--use-angle=swiftshader (ANGLE software) |
correct |
--use-angle=vulkan --enable-features=Vulkan (ANGLE Vulkan) |
correct |
Default ANGLE GLES backend (the *ACTIVE* one in the attached GPU info) |
black boxes |
Identical xterm.js output renders correctly under the DOM, SwiftShader, and Vulkan backends and in an external terminal, so xterm.js is not implicated — the defect is in the ANGLE OpenGL ES path (ANGLE GLES translation or the Mesa radeonsi GLES driver).
Workarounds
"terminal.integrated.gpuAcceleration": "off"(terminal-only DOM renderer).- Launch with
--use-angle=vulkan --enable-features=Vulkan(keeps the hardware WebGL terminal, off the GLES backend).
Drafted with assistance from Claude (Anthropic). The bisection and environment details above were run and verified by me on the affected machine.
VS Code version: Code 1.124.0 (1b50d58, 2026-06-09T21:29:32-07:00)
OS version: Linux x64 7.0.0-22-generic
Modes:
System Info
| Item | Value |
|---|---|
| CPUs | 13th Gen Intel(R) Core(TM) i5-13600KF (20 x 5100) |
| GPU Status | 2d_canvas: enabled GPU0: VENDOR= 0x1002 [Google Inc. (AMD)], DEVICE=0x73ff [ANGLE (AMD, AMD Radeon RX 6600 (radeonsi navi23 ACO), OpenGL ES 3.2 Mesa 26.0.3-1ubuntu1)], DRIVER_VENDOR=Mesa, DRIVER_VERSION=26.0.3 ACTIVE Machine model name: Machine model version: direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off trees_in_viz: disabled_off video_decode: enabled video_encode: disabled_software vulkan: disabled_off webgl: enabled webgpu: enabled webgpu_on_vk_via_gl_interop: disabled_off webnn: disabled_off |
| Load (avg) | 1, 1, 1 |
| Memory (System) | 123.38GB (110.47GB free) |
| Process Argv | --new-window |
| Screen Reader | no |
| VM | 0% |
| DESKTOP_SESSION | ubuntu |
| XDG_CURRENT_DESKTOP | ubuntu:GNOME |
| XDG_SESSION_DESKTOP | ubuntu |
| XDG_SESSION_TYPE | wayland |
Activity
MeKo-Christian commentedon Jun 12, 2026
Good analysis. I have the same issue
glubsy commentedon Jun 12, 2026
Same issue on Arch Linux.
Version: 1.124.2
Commit: 6928394
Date: 2026-06-12T00:12:36Z
Electron: 42.2.0
ElectronBuildId: 14159160
Chromium: 148.0.7778.97
Node.js: 24.15.0
V8: 14.8.178.14-electron.0
OS: Linux x64 7.0.9-arch1-1
Pulsar33550336 commentedon Jun 14, 2026
Encountering the same issue on NixOS.
Version: 1.123.0
Commit: 6a44c35
Date: 2026-06-03T11:29:03+02:00
Electron: 42.2.0
ElectronBuildId: 14159160
Chromium: 148.0.7778.97
Node.js: 24.15.0
V8: 14.8.178.14-electron.0
OS: Linux x64 7.0.12
NixOS unstable.