fallback to canvas renderer if webgl is not available, debug toggle for testing

[sawka]

No description provided.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 3693b73a-8ac8-4219-b656-91c0d6e3e1a3

📥 Commits

Reviewing files that changed from the base of the PR and between dbd2e8d and f23ca8e.

📒 Files selected for processing (1)

• frontend/app/view/term/termwrap.ts

---

Walkthrough

The changes add WebGL vs Canvas renderer selection and UI controls for the terminal. On the frontend, TermWrap exposes renderer state and lifecycle (setTermRenderer, getTermRenderer, isWebGlEnabled) and manages WebGL and Canvas addons and context-loss disposal; TermViewModel gains UI integration (getWebGlIconButton, getTermRenderer, isWebGlEnabled, toggleWebGl) to render a WebGL status/toggle button when the new debug:webglstatus setting is enabled. Type surfaces and schema are extended with the "debug:webglstatus" flag, a Go config constant and SettingsType field are added, and package.json adds the @xterm/addon-canvas dependency. Renderer selection falls back to Canvas when WebGL is unsupported or disabled.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Description check	❓ Inconclusive	No pull request description was provided by the author.	Add a meaningful description explaining the purpose, rationale, and testing considerations for the WebGL fallback and debug toggle feature.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main changes: adding a WebGL to canvas fallback mechanism and a debug toggle for testing.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

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• Create PR with unit tests
• Commit unit tests in branch sawka/webgl

📝 Coding Plan

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[coderabbitai]

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

frontend/app/view/term/termwrap.ts (1)

49-60: ⚠️ Potential issue | 🔴 Critical

Probe WebGL2, not WebGL1.

detectWebGLSupport() probes getContext("webgl"), but @xterm/addon-webgl v5.5.0 explicitly requires WebGL2 (getContext("webgl2")). On browsers that expose WebGL1 but not WebGL2, the detection passes and line 188 selects the WebGL renderer, causing the addon to throw "WebGL2 not supported" with no fallback to canvas.

Fix

 function detectWebGLSupport(): boolean {
     try {
         const canvas = document.createElement("canvas");
-        const ctx = canvas.getContext("webgl");
+        const ctx = canvas.getContext("webgl2");
         return !!ctx;
     } catch (e) {
         return false;
     }
 }

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@frontend/app/view/term/termwrap.ts` around lines 49 - 60, The WebGL detection
currently checks for WebGL1 which causes `@xterm/addon-webgl` v5.5.0 to fail;
update detectWebGLSupport() to request a "webgl2" context (e.g.,
canvas.getContext("webgl2")) and return true only if that succeeds, leaving the
try/catch behavior intact; ensure the exported WebGLSupported constant remains
tied to this updated detectWebGLSupport() so the code that chooses the renderer
(which reads WebGLSupported) will not select the WebGL addon on browsers that
only support WebGL1.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Outside diff comments:
In `@frontend/app/view/term/termwrap.ts`:
- Around line 49-60: The WebGL detection currently checks for WebGL1 which
causes `@xterm/addon-webgl` v5.5.0 to fail; update detectWebGLSupport() to request
a "webgl2" context (e.g., canvas.getContext("webgl2")) and return true only if
that succeeds, leaving the try/catch behavior intact; ensure the exported
WebGLSupported constant remains tied to this updated detectWebGLSupport() so the
code that chooses the renderer (which reads WebGLSupported) will not select the
WebGL addon on browsers that only support WebGL1.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 0d315c97-251b-4e21-9764-675cc9a06f4a

📥 Commits

Reviewing files that changed from the base of the PR and between 134b388 and dbd2e8d.

⛔ Files ignored due to path filters (1)

• package-lock.json is excluded by !**/package-lock.json

📒 Files selected for processing (7)

• frontend/app/view/term/term-model.ts
• frontend/app/view/term/termwrap.ts
• frontend/types/gotypes.d.ts
• package.json
• pkg/wconfig/metaconsts.go
• pkg/wconfig/settingsconfig.go
• schema/settings.json

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Overview

This PR implements a WebGL to Canvas fallback mechanism for the terminal renderer, along with a debug toggle for testing purposes. The implementation is well-structured and handles edge cases properly.

Changes Reviewed

1. termwrap.ts: WebGL detection now correctly checks for WebGL2 context (as required by @xterm/addon-webgl), with proper fallback to Canvas renderer. Added setTermRenderer, getTermRenderer, and isWebGlEnabled methods for runtime switching.

2. term-model.ts: Added WebGL toggle button functionality accessible via the debug:webglstatus config setting. The button properly reflects WebGL state and allows runtime switching.

3. Configuration: Added debug:webglstatus setting to enable the WebGL status button in the terminal header for testing.

4. Dependencies: Added @xterm/addon-canvas as a new dependency.

Key Implementation Details Verified

• WebGL context loss is handled by automatically falling back to Canvas
• Toggle logic correctly switches between WebGL and Canvas renderers
• Debug toggle is properly gated behind the debug:webglstatus setting
• Atom state management for WebGL enabled status is properly initialized

Files Reviewed (7 files)

• frontend/app/view/term/term-model.ts
• frontend/app/view/term/termwrap.ts
• frontend/types/gotypes.d.ts
• package.json
• pkg/wconfig/metaconsts.go
• pkg/wconfig/settingsconfig.go
• schema/settings.json