Alex Turchyn
39 lines
1000 B
JavaScript
39 lines
1000 B
JavaScript
function isValidSignatureCanvas (data) {
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if (data.length === 0) return false
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const strokes = data.filter(stroke => Array.isArray(stroke.points) && stroke.points.length > 2)
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if (strokes.length === 0) return false
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let skippedStraightLine = 0
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const validStrokes = strokes.filter(stroke => {
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const points = stroke.points
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const first = points[0]
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const last = points[points.length - 1]
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const A = last.y - first.y
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const B = first.x - last.x
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const C = last.x * first.y - first.x * last.y
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const lineLength = Math.sqrt(A * A + B * B)
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const totalDeviation = points.reduce((sum, p) => {
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const distanceToLine = Math.abs(A * p.x + B * p.y + C) / lineLength
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return sum + distanceToLine
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}, 0)
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const avgDeviation = totalDeviation / points.length
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if (avgDeviation < 3 && skippedStraightLine < 2) {
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skippedStraightLine++
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return false
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}
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return true
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})
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return validStrokes.length > 0
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}
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export { isValidSignatureCanvas }
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