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Add a basic GitHub Pages demo site #3

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Merged
kylesmile merged 2 commits into from
Dec 10, 2025
Merged

Add a basic GitHub Pages demo site #3

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14c5150
Add demo HTML page
kylesmile Dec 9, 2025
60a0d6b
Fix readme
kylesmile Dec 9, 2025
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2 changes: 2 additions & 0 deletions .npmignore
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Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
index.html
/.github/
6 changes: 4 additions & 2 deletions README.md
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Expand Up @@ -21,6 +21,8 @@ import ImageDiff from "@rolemodel/image-diff"

const originalImage = document.getElementById('base-image')
const newImage = document.getElementById('new-image')
const outputCanvas = document.getElementById('output-canvas')
const outputContext = outputCanvas.getContext('2d')
const imageDiff = new ImageDiff(originalImage, newImage)

const result = imageDiff.update({
Expand All @@ -29,8 +31,8 @@ const result = imageDiff.update({
backgroundAlpha: 1.0
})

// result is a canvas element
document.body.appendChild(result)
// result is an offscreen canvas
outputContext.drawImage(result, 0, 0)

imageDiff.dispose()
```
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145 changes: 145 additions & 0 deletions index.html
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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>@rolemodel/image-diff Demo</title>
<style>
body {
width: 400px;
display: flex;
flex-direction: column;
gap: 16px;
}

canvas {
border: 1px solid #000000;
cursor: crosshair;
}

.canvas-label {
font-weight: bold;
margin-bottom: 8px;
}

.canvas-options {
display: flex;
flex-direction: column;
align-items: flex-start;
gap: 8px;

margin-bottom: 8px;
}
</style>
</head>
<body>
<div class="canvas-option">
<label for="drawing-color">Drawing Color:</label>
<input type="color" id="drawing-color" value="#ff0000">
</div>

<div class="canvas-wrapper">
<div><span class="canvas-label">Original</span></div>
<canvas id="original"></canvas>
</div>

<div class="canvas-wrapper">
<div>
<span class="canvas-label">Modified</span>
<div class="canvas-options">
<button type="button" id="copy" class="copy-button">Copy from original</button>
</div>
</div>
<canvas id="modified"></canvas>
</div>

<div class="canvas-wrapper">
<div>
<span class="canvas-label">Result</span>
<div class="canvas-options">
<div class="canvas-option">
<label for="diff-threshold">Diff Threshold:</label>
<input type="range" id="diff-threshold" min="0" max="1" step="0.01" value="0.2">
</div>

<div class="canvas-option">
<label for="background-alpha">Background Alpha:</label>
<input type="range" id="background-alpha" min="0" max="1" step="0.01" value="1.0">
</div>

<div class="canvas-option">
<label for="diff-color">Diff Color:</label>
<input type="color" id="diff-color" value="#ff0000">
</div>
</div>
</div>
<canvas id="result"></canvas>
</div>

<script type="module">
import ImageDiff from './src/ImageDiff.js'

const originalCanvas = document.getElementById('original')
const originalContext = originalCanvas.getContext('2d')
const modifiedCanvas = document.getElementById('modified')
const modifiedContext = modifiedCanvas.getContext('2d')
const resultCanvas = document.getElementById('result')
const resultContext = resultCanvas.getContext('2d')

const copyButton = document.getElementById('copy')
const drawingColorInput = document.getElementById('drawing-color')

const diffThresholdInput = document.getElementById('diff-threshold')
const backgroundAlphaInput = document.getElementById('background-alpha')
const diffColorInput = document.getElementById('diff-color')

const diff = new ImageDiff(originalCanvas, modifiedCanvas)

function diffOptions() {
const hexColor = diffColorInput.value
const r = parseInt(hexColor.slice(1, 3), 16) / 255
const g = parseInt(hexColor.slice(3, 5), 16) / 255
const b = parseInt(hexColor.slice(5, 7), 16) / 255

return {
diffColor: { r, g, b },
threshold: parseFloat(diffThresholdInput.value),
backgroundAlpha: parseFloat(backgroundAlphaInput.value)
}
}

function updateDiff() {
const diffCanvas = diff.update(diffOptions())

resultContext.clearRect(0, 0, resultCanvas.width, resultCanvas.height)
resultContext.drawImage(diffCanvas, 0, 0)
}

function addCanvasEventListeners(canvasContext) {
canvasContext.canvas.addEventListener('pointermove', event => {
if (event.buttons !== 1) return
const rect = canvasContext.canvas.getBoundingClientRect()
const x = event.clientX - rect.left
const y = event.clientY - rect.top
const ctx = canvasContext
ctx.fillStyle = drawingColorInput.value
ctx.fillRect(x - 5, y - 5, 10, 10)
updateDiff()
})
}

addCanvasEventListeners(originalContext)
addCanvasEventListeners(modifiedContext)

copyButton.addEventListener('click', () => {
modifiedContext.clearRect(0, 0, modifiedCanvas.width, modifiedCanvas.height)
modifiedContext.drawImage(originalCanvas, 0, 0)
updateDiff()
})

diffThresholdInput.addEventListener('input', updateDiff)
backgroundAlphaInput.addEventListener('input', updateDiff)
diffColorInput.addEventListener('input', updateDiff)
</script>
</body>
</html>