diff options
| -rw-r--r-- | fpdf.go | 183 |
1 files changed, 0 insertions, 183 deletions
@@ -2900,189 +2900,6 @@ func (f *Fpdf) readByte(buf *bytes.Buffer) (val byte) { return } -func (f *Fpdf) parsepngstream(buf *bytes.Buffer, readdpi bool) (info *ImageInfoType) { - info = f.newImageInfo() - // Check signature - if string(buf.Next(8)) != "\x89PNG\x0d\x0a\x1a\x0a" { - f.err = fmt.Errorf("not a PNG buffer") - return - } - // Read header chunk - _ = buf.Next(4) - if string(buf.Next(4)) != "IHDR" { - f.err = fmt.Errorf("incorrect PNG buffer") - return - } - w := f.readBeInt32(buf) - h := f.readBeInt32(buf) - bpc := f.readByte(buf) - if bpc > 8 { - f.err = fmt.Errorf("16-bit depth not supported in PNG file") - } - ct := f.readByte(buf) - var colspace string - colorVal := 1 - switch ct { - case 0, 4: - colspace = "DeviceGray" - case 2, 6: - colspace = "DeviceRGB" - colorVal = 3 - case 3: - colspace = "Indexed" - default: - f.err = fmt.Errorf("unknown color type in PNG buffer: %d", ct) - } - if f.err != nil { - return - } - if f.readByte(buf) != 0 { - f.err = fmt.Errorf("'unknown compression method in PNG buffer") - return - } - if f.readByte(buf) != 0 { - f.err = fmt.Errorf("'unknown filter method in PNG buffer") - return - } - if f.readByte(buf) != 0 { - f.err = fmt.Errorf("interlacing not supported in PNG buffer") - return - } - _ = buf.Next(4) - dp := sprintf("/Predictor 15 /Colors %d /BitsPerComponent %d /Columns %d", colorVal, bpc, w) - // Scan chunks looking for palette, transparency and image data - pal := make([]byte, 0, 32) - var trns []int - data := make([]byte, 0, 32) - loop := true - for loop { - n := int(f.readBeInt32(buf)) - // dbg("Loop [%d]", n) - switch string(buf.Next(4)) { - case "PLTE": - // dbg("PLTE") - // Read palette - pal = buf.Next(n) - _ = buf.Next(4) - case "tRNS": - // dbg("tRNS") - // Read transparency info - t := buf.Next(n) - if ct == 0 { - trns = []int{int(t[1])} // ord(substr($t,1,1))); - } else if ct == 2 { - trns = []int{int(t[1]), int(t[3]), int(t[5])} // array(ord(substr($t,1,1)), ord(substr($t,3,1)), ord(substr($t,5,1))); - } else { - pos := strings.Index(string(t), "\x00") - if pos >= 0 { - trns = []int{pos} // array($pos); - } - } - _ = buf.Next(4) - case "IDAT": - // dbg("IDAT") - // Read image data block - data = append(data, buf.Next(n)...) - _ = buf.Next(4) - case "IEND": - // dbg("IEND") - loop = false - case "pHYs": - // dbg("pHYs") - // png files theoretically support different x/y dpi - // but we ignore files like this - // but if they're the same then we can stamp our info - // object with it - x := int(f.readBeInt32(buf)) - y := int(f.readBeInt32(buf)) - units := buf.Next(1)[0] - // fmt.Printf("got a pHYs block, x=%d, y=%d, u=%d, readdpi=%t\n", - // x, y, int(units), readdpi) - // only modify the info block if the user wants us to - if x == y && readdpi { - switch units { - // if units is 1 then measurement is px/meter - case 1: - info.dpi = float64(x) / 39.3701 // inches per meter - default: - info.dpi = float64(x) - } - } - _ = buf.Next(4) - default: - // dbg("default") - _ = buf.Next(n + 4) - } - if loop { - loop = n > 0 - } - } - if colspace == "Indexed" && len(pal) == 0 { - f.err = fmt.Errorf("missing palette in PNG buffer") - } - info.w = float64(w) - info.h = float64(h) - info.cs = colspace - info.bpc = int(bpc) - info.f = "FlateDecode" - info.dp = dp - info.pal = pal - info.trns = trns - // dbg("ct [%d]", ct) - if ct >= 4 { - // Separate alpha and color channels - var err error - data, err = sliceUncompress(data) - if err != nil { - f.err = err - return - } - var color, alpha bytes.Buffer - if ct == 4 { - // Gray image - width := int(w) - height := int(h) - length := 2 * width - var pos, elPos int - for i := 0; i < height; i++ { - pos = (1 + length) * i - color.WriteByte(data[pos]) - alpha.WriteByte(data[pos]) - elPos = pos + 1 - for k := 0; k < width; k++ { - color.WriteByte(data[elPos]) - alpha.WriteByte(data[elPos+1]) - elPos += 2 - } - } - } else { - // RGB image - width := int(w) - height := int(h) - length := 4 * width - var pos, elPos int - for i := 0; i < height; i++ { - pos = (1 + length) * i - color.WriteByte(data[pos]) - alpha.WriteByte(data[pos]) - elPos = pos + 1 - for k := 0; k < width; k++ { - color.Write(data[elPos : elPos+3]) - alpha.WriteByte(data[elPos+3]) - elPos += 4 - } - } - } - data = sliceCompress(color.Bytes()) - info.smask = sliceCompress(alpha.Bytes()) - if f.pdfVersion < "1.4" { - f.pdfVersion = "1.4" - } - } - info.data = data - return -} - // Extract info from a GIF data (via PNG conversion) func (f *Fpdf) parsegif(r io.Reader) (info *ImageInfoType) { data, err := bufferFromReader(r) |