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Merge pull request #1 from lmika/codex/create-static-webpage-with-canvas-and-form

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Add static logo canvas generator page
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Leon Mika 2025-09-12 17:20:13 +10:00 committed by GitHub
parent ad1d8a740a 5f7e3dad8e
commit 66379af07a
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index.html Normal file
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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Canvas Logo Generator</title>
<style>
body {
font-family: sans-serif;
padding: 20px;
background: #f0f0f0;
}
form {
margin-bottom: 10px;
}
canvas {
border: 1px solid #ccc;
display: block;
margin-bottom: 10px;
}
</style>
</head>
<body>
<form id="logoForm">
<label>Upper: <input type="text" id="upperText" name="Upper"></label>
<label>Lower: <input type="text" id="lowerText" name="Lower"></label>
<label>Background:
<select id="bgColor" name="Background">
<option value="#c0392b">Red</option>
<option value="#d35400">Orange</option>
<option value="#f39c12">Amber</option>
<option value="#27ae60">Green</option>
<option value="#16a085">Teal</option>
<option value="#2980b9">Blue</option>
<option value="#8e44ad">Purple</option>
<option value="#7f8c8d">Gray</option>
</select>
</label>
</form>
<canvas id="logoCanvas" width="80" height="80"></canvas>
<button id="downloadBtn">Download PNG</button>
<script src="script.js"></script>
</body>
</html>

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script.js Normal file
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(function() {
const canvas = document.getElementById('logoCanvas');
const ctx = canvas.getContext('2d');
const upperInput = document.getElementById('upperText');
const lowerInput = document.getElementById('lowerText');
const colorSelect = document.getElementById('bgColor');
const downloadBtn = document.getElementById('downloadBtn');
const PADDING = 15;
const LINE_WIDTH = 2;
function fitText(text, maxWidth, maxHeight) {
let size = maxHeight;
ctx.font = `bold ${size}px sans-serif`;
while (ctx.measureText(text).width > maxWidth && size > 8) {
size--;
ctx.font = `bold ${size}px sans-serif`;
}
return size;
}
function draw() {
const width = canvas.width;
const height = canvas.height;
ctx.clearRect(0, 0, width, height);
ctx.fillStyle = colorSelect.value;
ctx.fillRect(0, 0, width, height);
ctx.strokeStyle = 'white';
ctx.lineWidth = LINE_WIDTH;
const yLine = height / 2;
ctx.beginPath();
ctx.moveTo(PADDING, yLine);
ctx.lineTo(width - PADDING, yLine);
ctx.stroke();
const availableWidth = width - PADDING * 2;
const availableHeight = height - PADDING * 2;
const halfHeight = availableHeight / 2;
ctx.fillStyle = 'white';
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
const upper = upperInput.value.toUpperCase();
let fontSize = fitText(upper, availableWidth, halfHeight);
ctx.font = `bold ${fontSize}px sans-serif`;
ctx.fillText(upper, width / 2, PADDING + halfHeight / 2);
const lower = lowerInput.value.toUpperCase();
fontSize = fitText(lower, availableWidth, halfHeight);
ctx.font = `bold ${fontSize}px sans-serif`;
ctx.fillText(lower, width / 2, height - PADDING - halfHeight / 2);
}
upperInput.addEventListener('input', draw);
lowerInput.addEventListener('input', draw);
colorSelect.addEventListener('change', draw);
downloadBtn.addEventListener('click', function() {
const link = document.createElement('a');
link.download = 'logo.png';
link.href = canvas.toDataURL('image/png');
link.click();
});
draw();
})();