/**
* Credit goes to mgutt
* http://www.programmierer-forum.de/function-imagecreatefrombmp-welche-variante-laeuft-t143137.htm
* Modified by Fabien Menager to support RGB555 BMP format
*/
function imagecreatefrombmp($filename)
{
if (!function_exists("imagecreatetruecolor")) {
trigger_error("The PHP GD extension is required, but is not installed.", E_ERROR);
return false;
}
// version 1.00
if (!($fh = fopen($filename, 'rb'))) {
trigger_error('imagecreatefrombmp: Can not open ' . $filename, E_USER_WARNING);
return false;
}
$bytes_read = 0;
// read file header
$meta = unpack('vtype/Vfilesize/Vreserved/Voffset', fread($fh, 14));
// check for bitmap
if ($meta['type'] != 19778) {
trigger_error('imagecreatefrombmp: ' . $filename . ' is not a bitmap!', E_USER_WARNING);
return false;
}
// read image header
$meta += unpack('Vheadersize/Vwidth/Vheight/vplanes/vbits/Vcompression/Vimagesize/Vxres/Vyres/Vcolors/Vimportant', fread($fh, 40));
$bytes_read += 40;
// read additional bitfield header
if ($meta['compression'] == 3) {
$meta += unpack('VrMask/VgMask/VbMask', fread($fh, 12));
$bytes_read += 12;
}
// set bytes and padding
$meta['bytes'] = $meta['bits'] / 8;
$meta['decal'] = 4 - 4 * ($meta['width'] * $meta['bytes'] / 4 - floor($meta['width'] * $meta['bytes'] / 4));
if ($meta['decal'] == 4) {
$meta['decal'] = 0;
}
// obtain imagesize
if ($meta['imagesize'] < 1) {
$meta['imagesize'] = $meta['filesize'] - $meta['offset'];
// in rare cases filesize is equal to offset so we need to read physical size
if ($meta['imagesize'] < 1) {
$meta['imagesize'] = @filesize($filename) - $meta['offset'];
if ($meta['imagesize'] < 1) {
trigger_error('imagecreatefrombmp: Can not obtain filesize of ' . $filename . '!', E_USER_WARNING);
return false;
}
}
}
// calculate colors
$meta['colors'] = !$meta['colors'] ? pow(2, $meta['bits']) : $meta['colors'];
// read color palette
$palette = array();
if ($meta['bits'] < 16) {
$palette = unpack('l' . $meta['colors'], fread($fh, $meta['colors'] * 4));
// in rare cases the color value is signed
if ($palette[1] < 0) {
foreach ($palette as $i => $color) {
$palette[$i] = $color + 16777216;
}
}
}
// ignore extra bitmap headers
if ($meta['headersize'] > $bytes_read) {
fread($fh, $meta['headersize'] - $bytes_read);
}
// create gd image
$im = imagecreatetruecolor($meta['width'], $meta['height']);
$data = fread($fh, $meta['imagesize']);
// uncompress data
switch ($meta['compression']) {
case 1:
$data = Helpers::rle8_decode($data, $meta['width']);
break;
case 2:
$data = Helpers::rle4_decode($data, $meta['width']);
break;
}
$p = 0;
$vide = chr(0);
$y = $meta['height'] - 1;
$error = 'imagecreatefrombmp: ' . $filename . ' has not enough data!';
// loop through the image data beginning with the lower left corner
while ($y >= 0) {
$x = 0;
while ($x < $meta['width']) {
switch ($meta['bits']) {
case 32:
case 24:
if (!($part = substr($data, $p, 3))) {
trigger_error($error, E_USER_WARNING);
return $im;
}
$color = unpack('V', $part . $vide);
break;
case 16:
if (!($part = substr($data, $p, 2))) {
trigger_error($error, E_USER_WARNING);
return $im;
}
$color = unpack('v', $part);
if (empty($meta['rMask']) || $meta['rMask'] != 0xf800) {
$color[1] = (($color[1] & 0x7c00) >> 7) * 65536 + (($color[1] & 0x3e0) >> 2) * 256 + (($color[1] & 0x1f) << 3);
// 555
} else {
$color[1] = (($color[1] & 0xf800) >> 8) * 65536 + (($color[1] & 0x7e0) >> 3) * 256 + (($color[1] & 0x1f) << 3);
// 565
}
break;
case 8:
$color = unpack('n', $vide . substr($data, $p, 1));
$color[1] = $palette[$color[1] + 1];
break;
case 4:
$color = unpack('n', $vide . substr($data, floor($p), 1));
$color[1] = $p * 2 % 2 == 0 ? $color[1] >> 4 : $color[1] & 0xf;
$color[1] = $palette[$color[1] + 1];
break;
case 1:
$color = unpack('n', $vide . substr($data, floor($p), 1));
switch ($p * 8 % 8) {
case 0:
$color[1] = $color[1] >> 7;
break;
case 1:
$color[1] = ($color[1] & 0x40) >> 6;
break;
case 2:
$color[1] = ($color[1] & 0x20) >> 5;
break;
case 3:
$color[1] = ($color[1] & 0x10) >> 4;
break;
case 4:
$color[1] = ($color[1] & 0x8) >> 3;
break;
case 5:
$color[1] = ($color[1] & 0x4) >> 2;
break;
case 6:
$color[1] = ($color[1] & 0x2) >> 1;
break;
case 7:
$color[1] = $color[1] & 0x1;
break;
}
$color[1] = $palette[$color[1] + 1];
break;
default:
trigger_error('imagecreatefrombmp: ' . $filename . ' has ' . $meta['bits'] . ' bits and this is not supported!', E_USER_WARNING);
return false;
}
imagesetpixel($im, $x, $y, $color[1]);
$x++;
$p += $meta['bytes'];
}
$y--;
$p += $meta['decal'];
}
fclose($fh);
return $im;
}
