950f332cca
This avoids small gaps between QR code squares. I learnt about this approach from https://github.com/papnkukn/qrcode-svg
81 lines
2.6 KiB
Go
81 lines
2.6 KiB
Go
// Copyright 2020 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package qrbill
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import (
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"bytes"
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"fmt"
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svg "github.com/ajstarks/svgo"
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"github.com/makiuchi-d/gozxing"
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"github.com/makiuchi-d/gozxing/qrcode/encoder"
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)
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// renderResultSVG is a copy of renderResult from
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// gozxing/qrcode/qrcode_writer.go, adapted to output to SVG.
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func renderResultSVG(code *encoder.QRCode, width, height, quietZone int) ([]byte, error) {
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input := code.GetMatrix()
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if input == nil {
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return nil, gozxing.NewWriterException("IllegalStateException")
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}
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inputWidth := input.GetWidth()
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inputHeight := input.GetHeight()
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qrWidth := inputWidth + (quietZone * 2)
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qrHeight := inputHeight + (quietZone * 2)
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outputWidth := qrWidth
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if outputWidth < width {
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outputWidth = width
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}
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outputHeight := qrHeight
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if outputHeight < height {
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outputHeight = height
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}
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multiple := outputWidth / qrWidth
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if h := outputHeight / qrHeight; multiple > h {
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multiple = h
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}
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// Padding includes both the quiet zone and the extra white pixels to accommodate the requested
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// dimensions. For example, if input is 25x25 the QR will be 33x33 including the quiet zone.
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// If the requested size is 200x160, the multiple will be 4, for a QR of 132x132. These will
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// handle all the padding from 100x100 (the actual QR) up to 200x160.
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leftPadding := (outputWidth - (inputWidth * multiple)) / 2
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topPadding := (outputHeight - (inputHeight * multiple)) / 2
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var buf bytes.Buffer
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s := svg.New(&buf)
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s.Start(outputWidth, outputHeight)
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s.Rect(0, 0, outputWidth, outputHeight, "fill:white;stroke:white")
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s.Group(`shape-rendering="crispEdges"`)
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pathdata := ""
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for inputY, outputY := 0, topPadding; inputY < inputHeight; inputY, outputY = inputY+1, outputY+multiple {
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// Write the contents of this row of the barcode
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for inputX, outputX := 0, leftPadding; inputX < inputWidth; inputX, outputX = inputX+1, outputX+multiple {
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if input.Get(inputX, inputY) == 1 {
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pathdata += fmt.Sprintf("M%d,%d V%d H%d V%d H%d Z ",
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outputX, outputY, outputY+multiple, outputX+multiple, outputY, outputX)
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}
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}
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}
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s.Path(pathdata, "fill:black;stroke:none;")
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s.Gend()
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s.End()
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return buf.Bytes(), nil
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}
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