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const THUMBNAIL_MAX_WIDTH = 1280;
const THUMBNAIL_MAX_HEIGHT = 720;
export function thumbnailSize({
width,
height,
}: {
width: number;
height: number;
}): { width: number; height: number } {
const aspectRatio = width / height;
let targetWidth = width;
let targetHeight = height;
if (targetWidth > THUMBNAIL_MAX_WIDTH) {
targetWidth = THUMBNAIL_MAX_WIDTH;
targetHeight = Math.round(targetWidth / aspectRatio);
}
if (targetHeight > THUMBNAIL_MAX_HEIGHT) {
targetHeight = THUMBNAIL_MAX_HEIGHT;
targetWidth = Math.round(targetHeight * aspectRatio);
}
return { width: targetWidth, height: targetHeight };
}
export function renderThumbnailDataUrl({
width,
height,
draw,
}: {
width: number;
height: number;
draw: ({
context,
width,
height,
}: {
context: CanvasRenderingContext2D;
width: number;
height: number;
}) => void;
}): string {
const size = thumbnailSize({ width, height });
const canvas = document.createElement("canvas");
canvas.width = size.width;
canvas.height = size.height;
const context = canvas.getContext("2d");
if (!context) {
throw new Error("Could not get canvas context");
}
draw({ context, width: size.width, height: size.height });
return canvas.toDataURL("image/jpeg", 0.8);
}
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