func p6Enc(b []byte) []byte {
//
i := 4 * clz
_, _, w, h := dec(b[0:i])
cl := p6Codelen(w, h)
p := make([]byte, cl)
p6txt(w, 50)
p6txt(h, 55)
j := t6
copy(p[0:j], p6t)
if w == 0 || h == 0 {
return p
}
if underX {
xker.P6Encode(w, h, b[i:], p[j:])
} else {
di, dj := int(colourdepth), col.P6
for y := uint(0); y < h; y++ {
for x := uint(0); x < w; x++ {
col.P6Encode(b[i:i+di], p[j:j+dj])
i += di
j += dj
}
}
}
return p
}
func P6Encode(w, h uint, b, p []byte) {
//
i, j := uint(0), uint(0)
di := uint(clz)
for y := uint(0); y < h; y++ {
for x := uint(0); x < w; x++ {
col.P6Encode(b[i:i+di], p[j:j+col.P6])
i += di
j += col.P6
}
}
}