From d7f431d9cff6c4eae6f52f0fac07f162a3369047 Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Tue, 9 Jun 2026 16:47:25 -0700
Subject: [PATCH] Re-enable WebGL for remote-runtime terminals (#5048)

PR #4946 forced terminalGpuAcceleration to 'off' whenever a remote
runtime environment is active, as a conservative workaround alongside
the real fixes (CSS anchor-name encoding and rebuilding the WebGL
renderer after replay bytes parse). That left every remote-runtime
terminal on the slower DOM renderer even though the post-replay
rebuildPaneWebgl already covers the snapshot-after-attach race.

Remove the forced-off resolver so remote-runtime panes honor the user
GPU setting again. The snapshot path (onSnapshot -> processData with
replayingBufferedData -> onReplayData -> rebuildPaneWebgl after parse)
keeps the glyph atlas in sync, and attachWebgl re-checks all guards
(gpuRenderingEnabled, deferred attachment, context loss) on rebuild.

Co-authored-by: Orca <help@stably.ai>
---
 .../use-terminal-pane-lifecycle.test.ts       | 19 ------------
 .../use-terminal-pane-lifecycle.ts            | 31 ++++---------------
 2 files changed, 6 insertions(+), 44 deletions(-)

diff --git a/src/renderer/src/components/terminal-pane/use-terminal-pane-lifecycle.test.ts b/src/renderer/src/components/terminal-pane/use-terminal-pane-lifecycle.test.ts
index 8aee66514eb..8c7400939da 100644
--- a/src/renderer/src/components/terminal-pane/use-terminal-pane-lifecycle.test.ts
+++ b/src/renderer/src/components/terminal-pane/use-terminal-pane-lifecycle.test.ts
@@ -1,6 +1,5 @@
 import { describe, expect, it, vi } from 'vitest'
 import {
-  resolveTerminalGpuAccelerationForRuntime,
   shouldDetachPaneTransportOnUnmount,
   splitPaneWithOneShotStartup,
   suppressIntentionalPaneCloseExit
@@ -126,24 +125,6 @@ describe('shouldDetachPaneTransportOnUnmount', () => {
   })
 })
 
-describe('resolveTerminalGpuAccelerationForRuntime', () => {
-  it('forces DOM rendering while a remote runtime is active', () => {
-    expect(resolveTerminalGpuAccelerationForRuntime('env-1', 'on')).toBe('off')
-  })
-
-  it('honors the user GPU setting for local terminals', () => {
-    expect(resolveTerminalGpuAccelerationForRuntime(null, 'on')).toBe('on')
-  })
-
-  it('defaults local terminals to auto when the setting is missing', () => {
-    expect(resolveTerminalGpuAccelerationForRuntime(null, undefined)).toBe('auto')
-  })
-
-  it('treats blank runtime ids as local', () => {
-    expect(resolveTerminalGpuAccelerationForRuntime('   ', 'auto')).toBe('auto')
-  })
-})
-
 describe('suppressIntentionalPaneCloseExit', () => {
   it('suppresses the pane PTY exit before intentional close teardown destroys the transport', () => {
     const suppressPtyExit = vi.fn()
diff --git a/src/renderer/src/components/terminal-pane/use-terminal-pane-lifecycle.ts b/src/renderer/src/components/terminal-pane/use-terminal-pane-lifecycle.ts
index ecb8e78276e..7f721fc0d9f 100644
--- a/src/renderer/src/components/terminal-pane/use-terminal-pane-lifecycle.ts
+++ b/src/renderer/src/components/terminal-pane/use-terminal-pane-lifecycle.ts
@@ -310,16 +310,6 @@ export function shouldDetachPaneTransportOnUnmount(args: {
   )
 }
 
-export function resolveTerminalGpuAccelerationForRuntime(
-  activeRuntimeEnvironmentId: GlobalSettings['activeRuntimeEnvironmentId'] | null | undefined,
-  terminalGpuAcceleration: GlobalSettings['terminalGpuAcceleration'] | null | undefined
-): GlobalSettings['terminalGpuAcceleration'] {
-  if (activeRuntimeEnvironmentId?.trim()) {
-    return 'off'
-  }
-  return terminalGpuAcceleration ?? 'auto'
-}
-
 export function useTerminalPaneLifecycle({
   tabId,
   worktreeId,
@@ -1058,12 +1048,10 @@ export function useTerminalPaneLifecycle({
       // so PTYs survive navigation. Creating WebGL for those offscreen panes
       // still consumes Chromium's context budget and can blank visible panes.
       initialRenderingSuspended: !isVisibleRef.current,
-      // Why: remote-runtime snapshots arrive after pane open; WebGL can hold an
-      // empty atlas/canvas while the server-side buffer is already populated.
-      terminalGpuAcceleration: resolveTerminalGpuAccelerationForRuntime(
-        settingsRef.current?.activeRuntimeEnvironmentId,
-        settingsRef.current?.terminalGpuAcceleration
-      ),
+      // Why: remote-runtime panes honor the user GPU setting too — snapshots
+      // that arrive after WebGL attaches are handled by the post-replay
+      // rebuildPaneWebgl in pty-connection's replay callback.
+      terminalGpuAcceleration: settingsRef.current?.terminalGpuAcceleration ?? 'auto',
       debugLabel: `tab:${tabId}/wt:${worktreeId}`
     })
 
@@ -1382,15 +1370,8 @@ export function useTerminalPaneLifecycle({
   }, [settings, systemPrefersDark, effectiveMacOptionAsAlt])
 
   useEffect(() => {
-    // Why: remote-runtime panes stay on DOM rendering; local panes still honor
-    // the user's GPU setting and can switch live when settings change.
-    managerRef.current?.setTerminalGpuAcceleration(
-      resolveTerminalGpuAccelerationForRuntime(
-        settings?.activeRuntimeEnvironmentId,
-        settings?.terminalGpuAcceleration
-      )
-    )
-  }, [settings?.activeRuntimeEnvironmentId, settings?.terminalGpuAcceleration, managerRef])
+    managerRef.current?.setTerminalGpuAcceleration(settings?.terminalGpuAcceleration ?? 'auto')
+  }, [settings?.terminalGpuAcceleration, managerRef])
 
   useEffect(() => {
     const manager = managerRef.current