mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-30 07:32:45 +00:00
88 lines
1.8 KiB
Go
88 lines
1.8 KiB
Go
package pngstructure
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
|
|
"encoding/binary"
|
|
|
|
"github.com/dsoprea/go-logging"
|
|
)
|
|
|
|
type ChunkDecoder struct {
|
|
}
|
|
|
|
func NewChunkDecoder() *ChunkDecoder {
|
|
return new(ChunkDecoder)
|
|
}
|
|
|
|
func (cd *ChunkDecoder) Decode(c *Chunk) (decoded interface{}, err error) {
|
|
defer func() {
|
|
if state := recover(); state != nil {
|
|
err := log.Wrap(state.(error))
|
|
log.Panic(err)
|
|
}
|
|
}()
|
|
|
|
switch c.Type {
|
|
case "IHDR":
|
|
ihdr, err := cd.decodeIHDR(c)
|
|
log.PanicIf(err)
|
|
|
|
return ihdr, nil
|
|
}
|
|
|
|
// We don't decode this particular type.
|
|
return nil, nil
|
|
}
|
|
|
|
type ChunkIHDR struct {
|
|
Width uint32
|
|
Height uint32
|
|
BitDepth uint8
|
|
ColorType uint8
|
|
CompressionMethod uint8
|
|
FilterMethod uint8
|
|
InterlaceMethod uint8
|
|
}
|
|
|
|
func (ihdr *ChunkIHDR) String() string {
|
|
return fmt.Sprintf("IHDR<WIDTH=(%d) HEIGHT=(%d) DEPTH=(%d) COLOR-TYPE=(%d) COMP-METHOD=(%d) FILTER-METHOD=(%d) INTRLC-METHOD=(%d)>", ihdr.Width, ihdr.Height, ihdr.BitDepth, ihdr.ColorType, ihdr.CompressionMethod, ihdr.FilterMethod, ihdr.InterlaceMethod)
|
|
}
|
|
|
|
func (cd *ChunkDecoder) decodeIHDR(c *Chunk) (ihdr *ChunkIHDR, err error) {
|
|
defer func() {
|
|
if state := recover(); state != nil {
|
|
err := log.Wrap(state.(error))
|
|
log.Panic(err)
|
|
}
|
|
}()
|
|
|
|
b := bytes.NewBuffer(c.Data)
|
|
|
|
ihdr = new(ChunkIHDR)
|
|
|
|
err = binary.Read(b, binary.BigEndian, &ihdr.Width)
|
|
log.PanicIf(err)
|
|
|
|
err = binary.Read(b, binary.BigEndian, &ihdr.Height)
|
|
log.PanicIf(err)
|
|
|
|
err = binary.Read(b, binary.BigEndian, &ihdr.BitDepth)
|
|
log.PanicIf(err)
|
|
|
|
err = binary.Read(b, binary.BigEndian, &ihdr.ColorType)
|
|
log.PanicIf(err)
|
|
|
|
err = binary.Read(b, binary.BigEndian, &ihdr.CompressionMethod)
|
|
log.PanicIf(err)
|
|
|
|
err = binary.Read(b, binary.BigEndian, &ihdr.FilterMethod)
|
|
log.PanicIf(err)
|
|
|
|
err = binary.Read(b, binary.BigEndian, &ihdr.InterlaceMethod)
|
|
log.PanicIf(err)
|
|
|
|
return ihdr, nil
|
|
}
|