GLSL Shader Programming Skill

File Organization: This skill uses split structure. See references/ for advanced shader patterns.

1. Overview

This skill provides GLSL shader expertise for creating holographic visual effects in the JARVIS AI Assistant HUD. It focuses on efficient GPU programming for real-time rendering.

Risk Level: LOW - GPU-side code with limited attack surface, but can cause performance issues

Primary Use Cases:

• Holographic panel effects with scanlines
• Animated energy fields and particle systems
• Data visualization with custom rendering
• Post-processing effects (bloom, glitch, chromatic aberration)

2. Core Responsibilities

2.1 Fundamental Principles

1. TDD First: Write visual regression tests and shader unit tests before implementation
2. Performance Aware: Profile GPU performance, optimize for 60 FPS target
3. Precision Matters: Use appropriate precision qualifiers for performance
4. Avoid Branching: Minimize conditionals in shaders for GPU efficiency
5. Optimize Math: Use built-in functions, avoid expensive operations
6. Uniform Safety: Validate uniform inputs before sending to GPU
7. Loop Bounds: Always use constant loop bounds to prevent GPU hangs
8. Memory Access: Optimize texture lookups and varying interpolation

3. Implementation Workflow (TDD)

3.1 Step 1: Write Failing Test First

// tests/shaders/holographic-panel.test.ts
import { describe, it, expect, beforeEach } from 'vitest'
import { WebGLTestContext, captureFramebuffer, compareImages } from '../utils/webgl-test'

describe('HolographicPanelShader', () => {
  let ctx: WebGLTestContext

  beforeEach(() => {
    ctx = new WebGLTestContext(256, 256)
  })

  // Unit test: Shader compiles
  it('should compile without errors', () => {
    const shader = ctx.compileShader(holoFragSource, ctx.gl.FRAGMENT_SHADER)
    expect(shader).not.toBeNull()
    expect(ctx.getShaderErrors()).toEqual([])
  })

  // Unit test: Uniforms are accessible
  it('should have required uniforms', () => {
    const program = ctx.createProgram(vertSource, holoFragSource)
    expect(ctx.getUniformLocation(program, 'uTime')).not.toBeNull()
    expect(ctx.getUniformLocation(program, 'uColor')).not.toBeNull()
    expect(ctx.getUniformLocation(program, 'uOpacity')).not.toBeNull()
  })

  // Visual regression test
  it('should render scanlines correctly', async () => {
    ctx.renderShader(holoFragSource, { uTime: 0, uColor: [0, 0.5, 1], uOpacity: 1 })
    const result = captureFramebuffer(ctx)
    const baseline = await loadBaseline('holographic-scanlines.png')
    expect(compareImages(result, baseline, { threshold: 0.01 })).toBeLessThan(0.01)
  })

  // Edge case test
  it('should handle extreme UV values', () => {
    const testCases = [
      { uv: [0, 0], expected: 'no crash' },
      { uv: [1, 1], expected: 'no crash' },
      { uv: [0.5, 0.5], expected: 'no crash' }
    ]
    testCases.forEach(({ uv }) => {
      expect(() => ctx.renderAtUV(holoFragSource, uv)).not.toThrow()
    })
  })
})

3.2 Step 2: Implement Minimum to Pass

// Start with minimal shader that passes tests
#version 300 es
precision highp float;

uniform float uTime;
uniform vec3 uColor;
uniform float uOpacity;

in vec2 vUv;
out vec4 fragColor;

void main() {
  // Minimal implementation to pass compilation test
  fragColor = vec4(uColor, uOpacity);
}

3.3 Step 3: Refactor with Full Implementation

// Expand to full implementation after tests pass
void main() {
  vec2 uv = vUv;
  float scanline = sin(uv.y * 100.0) * 0.1 + 0.9;
  float pulse = sin(uTime * 2.0) * 0.1 + 0.9;
  vec3 color = uColor * scanline * pulse;
  fragColor = vec4(color, uOpacity);
}

3.4 Step 4: Run Full Verification

# Run all shader tests
npm run test:shaders

# Visual regression tests
npm run test:visual -- --update-snapshots  # First time only
npm run test:visual

# Performance benchmark
npm run bench:shaders

# Cross-browser compilation check
npm run test:webgl-compat

4. Technology Stack & Versions

4.1 GLSL Versions

4.2 Shader Setup

#version 300 es
precision highp float;
precision highp int;

// WebGL 2.0 shader header

5. Performance Patterns

5.1 Avoid Branching - Use Mix/Step

// ❌ BAD - GPU branch divergence
vec3 getColor(float value) {
  if (value < 0.3) {
    return vec3(1.0, 0.0, 0.0);  // Red
  } 
how to use glsl
CursorClaude CodeClineCodexWindsurfGooseGitHub CopilotVS CodeGemini CLIKiloOpencodeKimi CLIRoo ClineAiderContinueZedBolt.newLovablev0Replit AgentSweepSmol DeveloperDevinCavemanAmpAntigravity
How to use glsl on Cursor
AI-first code editor with Composer
1
Prerequisites
Before installing skills in Cursor, ensure your development environment meets these requirements:
›Cursor installed and configured on your development machine
›Node.js version 16.0+ with npm package manager (verify with node --version)
›Active project directory or workspace where you want to add glsl
2
Execute installation command
Execute the skills CLI command in your project's root directory to begin installation:
$npx skills add https://github.com/martinholovsky/claude-skills-generator --skill glslcopy
The skills CLI fetches glsl from GitHub repository martinholovsky/claude-skills-generator and configures it for Cursor.
3
Select Cursor when prompted
The CLI will show a list of available agents. Use arrow keys to navigate and space to select Cursor:
◆ Which agents do you want to install to?
│
│ ── Universal (.agents/skills) ── always included ────
│   • Amp
│   • Antigravity
│   • Cline
│   • Codex
│ ●Cursor(selected)
│   • Cursor
│   • Windsurf
4
Verify installation
Confirm successful installation by checking the skill directory location:
.cursor/skills/glsl
Reload or restart Cursor to activate glsl. Access the skill through slash commands (e.g., /glsl) or your agent's skill management interface.
⚠
Security & Verification Notice
We perform automated surface-level scans (Gen AI Scanner, Socket, Snyk) during installation. These checks detect common vulnerabilities but do not guarantee complete security. Always review skill source code and verify the publisher's reputation before production use.
Skills execute code in your development environment. Always verify the publisher's identity, review recent commits, and test in isolated environments before production deployment.
Additional Resources
›View source code on GitHub›Skills CLI documentation›Learn more about Cursor›What are agent skills?