54 lines
971 B
Go
54 lines
971 B
Go
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package png2ico
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import (
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"bytes"
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"encoding/binary"
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)
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type iconDir struct {
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reserved uint16
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imageType uint16
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numImages uint16
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}
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type iconDirEntry struct {
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imageWidth uint8
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imageHeight uint8
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numColors uint8
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reserved uint8
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colorPlanes uint16
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bitsPerPixel uint16
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sizeInBytes uint32
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offset uint32
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}
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func newIconDir() iconDir {
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return iconDir{imageType: 1, numImages: 1}
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}
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func newIconDirEntry() iconDirEntry {
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return iconDirEntry{colorPlanes: 1, bitsPerPixel: 32, offset: 22}
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}
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func ConvertPngToIco(im []byte, width, height int) ([]byte, error) {
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id := newIconDir()
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ide := newIconDirEntry()
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ide.sizeInBytes = uint32(len(im))
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ide.imageWidth = uint8(width)
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ide.imageHeight = uint8(height)
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bb := new(bytes.Buffer)
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err := binary.Write(bb, binary.LittleEndian, id)
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if err != nil {
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return nil, err
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}
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err = binary.Write(bb, binary.LittleEndian, ide)
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if err != nil {
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return nil, err
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}
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bb.Write(im)
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return bb.Bytes(), nil
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}
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