1 files changed, 81 insertions, 0 deletions
diff --git a/vendor/github.com/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go b/vendor/github.com/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go
new file mode 100644
index 000000000..518bc91ad
--- /dev/null
+++ b/vendor/github.com/superseriousbusiness/go-png-image-structure/v2/chunk_decoder.go
@@ -0,0 +1,81 @@
+package pngstructure
+
+import (
+	"bytes"
+	"fmt"
+
+	"encoding/binary"
+)
+
+type ChunkDecoder struct {
+}
+
+func NewChunkDecoder() *ChunkDecoder {
+	return new(ChunkDecoder)
+}
+
+func (cd *ChunkDecoder) Decode(c *Chunk) (decoded interface{}, err error) {
+	switch c.Type {
+	case "IHDR":
+		return cd.decodeIHDR(c)
+	}
+
+	// We don't decode this 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) (*ChunkIHDR, error) {
+	var (
+		b     = bytes.NewBuffer(c.Data)
+		ihdr  = new(ChunkIHDR)
+		readf = func(data interface{}) error {
+			return binary.Read(b, binary.BigEndian, data)
+		}
+	)
+
+	if err := readf(&ihdr.Width); err != nil {
+		return nil, err
+	}
+
+	if err := readf(&ihdr.Height); err != nil {
+		return nil, err
+	}
+
+	if err := readf(&ihdr.BitDepth); err != nil {
+		return nil, err
+	}
+
+	if err := readf(&ihdr.ColorType); err != nil {
+		return nil, err
+	}
+
+	if err := readf(&ihdr.CompressionMethod); err != nil {
+		return nil, err
+	}
+
+	if err := readf(&ihdr.FilterMethod); err != nil {
+		return nil, err
+	}
+
+	if err := readf(&ihdr.InterlaceMethod); err != nil {
+		return nil, err
+	}
+
+	return ihdr, nil
+}