package draw9 import (	"bitbucket.org/mischief/draw9/color9"	"fmt"	"io"	"strings") func (d *Display) creadimage(rd io.Reader) (*Image, error) {	fd := rd	hdr := make([]byte, 5*12) 	_, err := io.ReadFull(fd, hdr)	if err != nil {		return nil, fmt.Errorf("reading image header: %v", err)	} 	/*	 * distinguish new channel descriptor from old ldepth.	 * channel descriptors have letters as well as numbers,	 * while ldepths are a single digit formatted as %-11d.	 */	new := false	for m := 0; m < 10; m++ {		if hdr[m] != ' ' {			new = true			break		}	}	if hdr[11] != ' ' {		return nil, fmt.Errorf("creadimage: bad format")	}	var pix color9.Pix	if new {		pix, err = color9.ParsePix(strings.TrimSpace(string(hdr[:12])))		if err != nil {			return nil, fmt.Errorf("creadimage: %v", err)		}	} else {		ldepth := int(hdr[10]) - '0'		if ldepth < 0 || ldepth > 3 {			return nil, fmt.Errorf("creadimage: bad ldepth %d", ldepth)		}		pix = ldepthToPix[ldepth]	}	r := ator(hdr[1*12:])	if r.Min.X > r.Max.X || r.Min.Y > r.Max.Y {		return nil, fmt.Errorf("creadimage: bad rectangle")	} 	var i *Image	if d != nil {		i, err = d.allocImage(r, pix, false, 0)		if err != nil {			return nil, err		}	} else {		i = &Image{R: r, Pix: pix, Depth: pix.Depth()}	} 	ncblock := compblocksize(r, pix.Depth())	buf := make([]byte, ncblock)	miny := r.Min.Y	for miny != r.Max.Y {		if _, err = io.ReadFull(fd, hdr[:2*12]); err != nil {			goto Errout		}		maxy := atoi(hdr[0*12:])		nb := atoi(hdr[1*12:])		if maxy <= miny || r.Max.Y < maxy {			err = fmt.Errorf("creadimage: bad maxy %d", maxy)			goto Errout		}		if nb <= 0 || ncblock < nb {			err = fmt.Errorf("creadimage: bad count %d", nb)			goto Errout		}		if _, err = io.ReadFull(fd, buf[:nb]); err != nil {			goto Errout		}		if d != nil {			a := d.bufimage(21 + nb)			// XXX err			if err != nil {				goto Errout			}			a[0] = 'Y'			bplong(a[1:], i.ID)			bplong(a[5:], uint32(r.Min.X))			bplong(a[9:], uint32(miny))			bplong(a[13:], uint32(r.Max.X))			bplong(a[17:], uint32(maxy))			if !new { // old image: flip the data bits				twiddlecompressed(buf[:nb])			}			copy(a[21:], buf)		}		miny = maxy	}	return i, nil Errout:	if d != nil {		i.free()	}	return nil, err}