Fix terminal glyph renderer fallback (#1850)

* fix terminal glyph renderer fallback

* remove terminal glyph design doc from pr

src/renderer/src/components/terminal-pane/pty-connection.ts

@@ -12,7 +12,7 @@ import { safeFit } from '@/lib/pane-manager/pane-tree-ops'
 import { getFitOverrideForPty, bindPanePtyId } from '@/lib/pane-manager/mobile-fit-overrides'
 import { isPtyLocked } from '@/lib/pane-manager/mobile-driver-state'
 import { isPaneReplaying, replayIntoTerminal } from './replay-guard'
-import { terminalOutputRequiresDomRenderer } from '@/lib/pane-manager/terminal-complex-script'
+import { terminalOutputPrefersDomRenderer } from '@/lib/pane-manager/terminal-complex-script'
 import {
   paneLeafId,
   POST_REPLAY_MODE_RESET,
@@ -626,7 +626,7 @@ export function connectPanePty(
       // Why: drain any queued background bytes BEFORE the replay paint, so the
       // scheduler's deferred drain cannot land older bytes on top of the replay.
       flushTerminalOutput(pane.terminal)
-      if (terminalOutputRequiresDomRenderer(data)) {
+      if (terminalOutputPrefersDomRenderer(data)) {
         manager.markPaneHasComplexScriptOutput(pane.id)
       }
       replayIntoTerminal(pane, deps.replayingPanesRef, data)
@@ -641,7 +641,7 @@ export function connectPanePty(
     }
 
     const dataCallback = (data: string): void => {
-      if (terminalOutputRequiresDomRenderer(data)) {
+      if (terminalOutputPrefersDomRenderer(data)) {
         manager.markPaneHasComplexScriptOutput(pane.id)
       }
       // Why: visibility is the right gate — split-pane layouts have multiple

src/renderer/src/lib/pane-manager/terminal-complex-script.test.ts

@@ -1,16 +1,44 @@
 import { describe, expect, it } from 'vitest'
-import { terminalOutputRequiresDomRenderer } from './terminal-complex-script'
+import { terminalOutputPrefersDomRenderer } from './terminal-complex-script'
 
-describe('terminalOutputRequiresDomRenderer', () => {
+describe('terminalOutputPrefersDomRenderer', () => {
   it('detects Arabic terminal output', () => {
-    expect(terminalOutputRequiresDomRenderer('Arabic: السلام عليكم')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('Arabic: السلام عليكم')).toBe(true)
   })
 
   it('detects RTL scripts that need browser text shaping/order', () => {
-    expect(terminalOutputRequiresDomRenderer('Hebrew: שלום')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('Hebrew: שלום')).toBe(true)
   })
 
-  it('does not disable WebGL for ordinary terminal output', () => {
-    expect(terminalOutputRequiresDomRenderer('abc 123 ── ✓')).toBe(false)
+  it('detects glyph classes common in agent terminal UIs', () => {
+    expect(terminalOutputPrefersDomRenderer('⠋ Working')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('├─ file.ts')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('█ progress')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('◆ status')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('\uE0B0 prompt')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('bad replacement �')).toBe(true)
+  })
+
+  it('detects emoji and variation sequences', () => {
+    expect(terminalOutputPrefersDomRenderer('status 🚀')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('developer 👩‍💻')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('heart ♥️')).toBe(true)
+  })
+
+  it('detects supplementary-plane complex-script ranges', () => {
+    expect(terminalOutputPrefersDomRenderer('Adlam: 𞤀')).toBe(true)
+    expect(terminalOutputPrefersDomRenderer('Medefaidrin: 𐻀')).toBe(true)
+  })
+
+  it('detects split surrogate chunks so fallback is not lost at chunk boundaries', () => {
+    const [high, low] = Array.from('🚀')[0].split('')
+
+    expect(terminalOutputPrefersDomRenderer(high)).toBe(true)
+    expect(terminalOutputPrefersDomRenderer(low)).toBe(true)
+  })
+
+  it('does not disable WebGL for ordinary terminal output or ANSI controls alone', () => {
+    expect(terminalOutputPrefersDomRenderer('abc 123 ✓')).toBe(false)
+    expect(terminalOutputPrefersDomRenderer('\x1b[32mplain green\x1b[0m')).toBe(false)
   })
 })

src/renderer/src/lib/pane-manager/terminal-complex-script.ts

@@ -1,8 +1,45 @@
-// Why: xterm's WebGL renderer draws per-cell glyphs from a texture atlas,
-// bypassing the browser shaping/bidi path that the DOM renderer provides.
-const COMPLEX_SCRIPT_PATTERN =
-  /[\u0590-\u05FF\u0600-\u06FF\u0700-\u074F\u0750-\u077F\u0780-\u07BF\u07C0-\u07FF\u0840-\u085F\u0860-\u086F\u0870-\u089F\u08A0-\u08FF\uFB1D-\uFDFF\uFE70-\uFEFF]|\u{10EC0}-\u{10EFF}|\u{1E900}-\u{1E95F}/u
+// Why: xterm WebGL renders from a glyph atlas; agent TUIs often combine glyphs
+// that are safer through the browser text path even when they are not RTL.
+const EMOJI_PRESENTATION_PATTERN = /\p{Emoji_Presentation}/u
 
-export function terminalOutputRequiresDomRenderer(data: string): boolean {
-  return COMPLEX_SCRIPT_PATTERN.test(data)
+function isInRange(value: number, start: number, end: number): boolean {
+  return value >= start && value <= end
+}
+
+function isRendererRiskCodePoint(value: number): boolean {
+  return (
+    isInRange(value, 0x0590, 0x08ff) ||
+    value === 0x200d ||
+    isInRange(value, 0x2500, 0x259f) ||
+    isInRange(value, 0x25a0, 0x25ff) ||
+    isInRange(value, 0x2800, 0x28ff) ||
+    isInRange(value, 0xd800, 0xdfff) ||
+    isInRange(value, 0xe000, 0xf8ff) ||
+    isInRange(value, 0xfb1d, 0xfdff) ||
+    isInRange(value, 0xfe00, 0xfe0f) ||
+    isInRange(value, 0xfe70, 0xfeff) ||
+    value === 0xfffd ||
+    isInRange(value, 0x10ec0, 0x10eff) ||
+    isInRange(value, 0x1e900, 0x1e95f) ||
+    isInRange(value, 0xe0100, 0xe01ef)
+  )
+}
+
+export function terminalOutputPrefersDomRenderer(data: string): boolean {
+  if (EMOJI_PRESENTATION_PATTERN.test(data)) {
+    return true
+  }
+  for (let i = 0; i < data.length; i += 1) {
+    const codePoint = data.codePointAt(i)
+    if (codePoint === undefined) {
+      continue
+    }
+    if (isRendererRiskCodePoint(codePoint)) {
+      return true
+    }
+    if (codePoint > 0xffff) {
+      i += 1
+    }
+  }
+  return false
 }