private function _loadLBM($file)
{
$lbm = fopen($file, "rb");
if (!$lbm) {
return false;
}
fseek($lbm, 0, SEEK_END);
$size = ftell($lbm);
fseek($lbm, 0, SEEK_SET);
$form = file_helpers::freadstring($lbm, 4, false);
if ($form != "FORM") {
return $this->_error("not a LBM file");
}
$length = file_helpers::freadint($lbm);
$pbm = file_helpers::freadstring($lbm, 4, false);
if ($pbm != "PBM ") {
return $this->_error("not a LBM file with PBM structure");
}
while (!feof($lbm) && ftell($lbm) < $size) {
$chunk = file_helpers::freadstring($lbm, 4, false);
// Länge einlesen
$length = file_helpers::freadbint($lbm);
#echo $chunk." = ".$length."<br>\n";
// Bei ungerader Zahl aufrunden
if ($length & 1) {
++$length;
}
switch ($chunk) {
case "BMHD":
// Breite & Höhe einlesen
$this->image['header']['width'] = file_helpers::freadbshort($lbm);
$this->image['header']['height'] = file_helpers::freadbshort($lbm);
// Unbekannte Daten ( 4 Byte ) berspringen
fseek($lbm, 4, SEEK_CUR);
// Farbtiefe einlesen
$this->image['header']['depth'] = file_helpers::freadshort($lbm);
// Nur 256 Farben und nicht mehr!
if ($this->image['header']['depth'] != 8) {
$this->_error("Invalid File: LBM with 8bit colors are supported only");
return false;
}
// Kompressionflag lesen
$this->image['header']['compression'] = file_helpers::freadshort($lbm);
if ($this->image['header']['compression'] != 1) {
$this->_error("Invalid File: LBM has unknown compression flag: " . $this->image['header']['compression']);
return false;
}
$length -= 12;
// Rest überspringen
fseek($lbm, $length, SEEK_CUR);
break;
case "BODY":
switch ($this->image['header']['compression']) {
case 0:
// uncompressed
return false;
case 1:
$pos = 0;
// Solange einlesen, bis Block zuende bzw. Datei zuende ist
while ($length >= 0 && !feof($lbm) && ftell($lbm) < $size) {
// Typ lesen
$ctype = file_helpers::freadchar($lbm);
--$length;
if ($length == 0) {
continue;
}
if ($ctype < 128) {
for ($i = 0; $i <= $ctype; ++$i) {
$this->image['body'][$pos] = file_helpers::freadchar($lbm);
--$length;
++$pos;
}
} else {
$count = 0xff - $ctype + 1;
$color = file_helpers::freadchar($lbm);
--$length;
for ($i = 0; $i <= $count; ++$i) {
$this->image['body'][$pos] = $color;
++$pos;
}
}
}
if ($pos < $this->image['header']['width'] * $this->image['header']['height']) {
$this->_error("ooops? {$pos} " . $this->image['header']['width'] * $this->image['header']['height']);
return false;
}
break;
}
break;
case "CMAP":
if ($length != 256 * 3) {
$this->_error("Invalid Chunk: {$chunk} with length {$length} does not have 256 rgb values");
return false;
}
$this->palette->set_256rgb(s2pal::read_256rgb($lbm));
break;
case "DPPS":
// known but unused
// known but unused
case "CRNG":
case "TINY":
fseek($lbm, $length, SEEK_CUR);
break;
default:
$this->_error("Unknown Chunk: {$chunk} with length {$length}");
// Rest überspringen
fseek($lbm, $length, SEEK_CUR);
break;
}
}
fclose($lbm);
return true;
}
