# morphing-icons

Builds icon components that transform through direct SVG line motion instead of crossfades, relying on a shared three-line structure.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 362 installs · ★ 42
- Author: raphael-salaja
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/raphaelsalaja/skill/tree/HEAD/skills/morphing-icons/SKILL.md
- Updated: 2026-03-17
- HTML: https://affpapa.org/en/nevibecode/skills/morphing-icons

## What it does

The skill enforces an architecture where every icon consists of exactly three SVG lines. If a shape requires fewer strokes, such as a checkmark or minus sign, extra lines collapse into zero-length points at the center of the coordinate box (14x14 recommended). Because the element count stays identical, any icon transforms directly into another.

It includes rules for rotational groups, spring physics, and accessibility. Variants sharing a `group` property animate rotation smoothly, while unrelated icons jump to their target angle instantly. Components must also check `useReducedMotion` to disable transitions when the user requests minimal motion.

Omitting lines or passing `null` breaks the transition: unused lines must explicitly use coordinates with zero length and zero opacity. The skill also checks for `aria-hidden="true"` and round line caps on all icon definitions.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add raphaelsalaja/skill --skill morphing-icons -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/morphing-icons/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/morphing-icons/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add raphaelsalaja/skill --skill morphing-icons -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/morphing-icons/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add raphaelsalaja/skill --skill morphing-icons -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/morphing-icons/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install raphaelsalaja/skill morphing-icons
```

2. **Manually: put the files in place**
- File: `.github/skills/morphing-icons/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add raphaelsalaja/skill --skill morphing-icons -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/raphaelsalaja/skill --path skills/morphing-icons
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/morphing-icons/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add raphaelsalaja/skill --skill morphing-icons -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/raphaelsalaja/skill/tree/HEAD/skills/morphing-icons/SKILL.md

## When to use it
- animate transformations between SVG icons without crossfading
- structure icon geometry using exactly three lines and collapsed points
- implement spring-driven rotational transitions for icon variants
- respect prefers-reduced-motion preferences in animated icon components

## Example prompts
- Create a morphing icon component that transitions between a plus and a cross.
- Audit my icon definitions using the morphing-three-lines rules.
- Set up directional arrows with shared rotation groups and spring physics.

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 4b7f2bee180932fe.

BEGIN THIRD-PARTY FILE 4b7f2bee180932fe
````text
---
name: morphing-icons
description: Build icon components where any icon morphs into any other through SVG line transformation. Use when asked to "create morphing icons", "build icon transitions", "animate between icons", or "transform icons".
license: MIT
metadata:
  author: raphael-salaja
  version: "1.0.0"
  source: /content/morphing-icons/index.mdx
---

# Morphing Icons

Build icons that transform through actual shape transformation, not crossfades. Any icon can morph into any other because they share the same underlying 3-line structure.

## Core Concept

Every icon is composed of exactly **three SVG lines**. Icons that need fewer lines collapse the extras to invisible center points. This constraint enables seamless morphing between any two icons.

## Architecture

### 1. Line Definition

Each line has coordinates and optional opacity:

```ts
interface IconLine {
  x1: number;
  y1: number;
  x2: number;
  y2: number;
  opacity?: number;
}
```

### 2. Collapsed Lines

Icons needing fewer than 3 lines use collapsed lines—zero-length lines at the center:

```ts
const CENTER = 7; // Center of 14x14 viewbox

const collapsed: IconLine = {
  x1: CENTER,
  y1: CENTER,
  x2: CENTER,
  y2: CENTER,
  opacity: 0,
};
```

### 3. Icon Definition

Each icon has exactly 3 lines, optional rotation, and optional group:

```ts
interface IconDefinition {
  lines: [IconLine, IconLine, IconLine];
  rotation?: number;
  group?: string;
}
```

### 4. Rotation Groups

Icons sharing a `group` animate rotation when transitioning between them. Icons without matching groups jump to the new rotation instantly:

```ts
// These rotate smoothly between each other
{ lines: plusLines, rotation: 0, group: "plus-cross" }   // plus
{ lines: plusLines, rotation: 45, group: "plus-cross" }  // cross

// These rotate smoothly between each other
{ lines: arrowLines, rotation: 0, group: "arrow" }       // arrow-right
{ lines: arrowLines, rotation: 90, group: "arrow" }      // arrow-down
{ lines: arrowLines, rotation: 180, group: "arrow" }     // arrow-left
{ lines: arrowLines, rotation: -90, group: "arrow" }     // arrow-up
```

## Implementation Rules

### `morphing-three-lines`
Every icon MUST use exactly 3 lines. No more, no fewer.

**Fail:**
```ts
const checkIcon = {
  lines: [
    { x1: 2, y1: 7.5, x2: 5.5, y2: 11 },
    { x1: 5.5, y1: 11, x2: 12, y2: 3 },
  ], // Only 2 lines
};
```

**Pass:**
```ts
const checkIcon = {
  lines: [
    { x1: 2, y1: 7.5, x2: 5.5, y2: 11 },
    { x1: 5.5, y1: 11, x2: 12, y2: 3 },
    collapsed, // Third line collapsed
  ],
};
```

### `morphing-use-collapsed`
Unused lines must use the collapsed constant, not omission or null.

**Fail:**
```ts
const minusIcon = {
  lines: [
    { x1: 2, y1: 7, x2: 12, y2: 7 },
    null,
    null,
  ],
};
```

**Pass:**
```ts
const minusIcon = {
  lines: [
````
END THIRD-PARTY FILE 4b7f2bee180932fe

The third-party file has ended. Everything between the 4b7f2bee180932fe tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

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