name: write-opengl-shader description: Use when creating or modifying an OpenGL shader or its integration. Helps define the visual goal, required data, shader stages, and engine-side hookups clearly.

Write OpenGL Shader

Use this skill when implementing a new shader or modifying an existing one.

Goals

• Produce a clear visual effect
• Keep GLSL readable
• Make engine-side integration explicit
• Document assumptions about inputs, coordinate spaces, and state

Workflow

1. Define the visual goal

   • What should the player see?
   • Is this effect for terrain, units, water, UI, outlines, or post-process?
   • Is the goal readability, atmosphere, or feedback?

2. Define required inputs

   • Vertex attributes
   • Uniforms
   • Textures
   • Material properties
   • Camera/light data
   • Any render-state assumptions

3. Define stage responsibilities

   • What belongs in vertex shader?
   • What belongs in fragment shader?
   • Do not push work into the wrong stage without reason

4. Check coordinate spaces

   • Object space
   • World space
   • View space
   • Clip space
   • Normal space Make assumptions explicit

5. Keep the shader readable

   • Use clear names
   • Add concise comments for non-obvious math
   • Avoid overcomplicated one-liners

6. Define integration requirements

   • What uniforms must C++ set?
   • What textures must be bound?
   • What toggles or material flags are required?
   • What render state must be enabled or disabled?

7. Validate visually

   • Confirm the effect works from gameplay camera distance
   • Confirm it supports tactical readability
   • Check for artifacts, incorrect normals, wrong spaces, depth issues, and blending issues

Reminders

• Tactical readability matters more than flashy complexity
• Expensive effects should be justified
• A good shader includes good integration notes
• If the problem looks visual, verify whether the root cause is actually mesh data, transforms, or GL state