58 lines
920 B
Go
58 lines
920 B
Go
package pdf417
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import "math"
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const (
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minCols = 2
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maxCols = 30
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maxRows = 30
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minRows = 2
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moduleHeight = 2
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preferred_ratio = 3.0
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)
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func calculateNumberOfRows(m, k, c int) int {
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r := ((m + 1 + k) / c) + 1
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if c*r >= (m + 1 + k + c) {
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r--
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}
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return r
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}
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func calcDimensions(dataWords, eccWords int) (cols, rows int) {
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ratio := 0.0
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cols = 0
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rows = 0
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for c := minCols; c <= maxCols; c++ {
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r := calculateNumberOfRows(dataWords, eccWords, c)
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if r < minRows {
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break
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}
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if r > maxRows {
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continue
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}
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newRatio := float64(17*cols+69) / float64(rows*moduleHeight)
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if rows != 0 && math.Abs(newRatio-preferred_ratio) > math.Abs(ratio-preferred_ratio) {
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continue
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}
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ratio = newRatio
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cols = c
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rows = r
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}
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if rows == 0 {
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r := calculateNumberOfRows(dataWords, eccWords, minCols)
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if r < minRows {
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rows = minRows
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cols = minCols
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}
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}
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return
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}
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