<?php

/**
 * imagecreatefrombmp converts a bmp to an image resource
 *
 * @author http://www.programmierer-forum.de/function-imagecreatefrombmp-laeuft-mit-allen-bitraten-t143137.htm
 */

if (!function_exists('imagecreatefrombmp')) {

	function imagecreatefrombmp($filename) {
		// version 1.00
		if (!($fh = fopen($filename, 'rb'))) {
			trigger_error( sprintf( __( 'imagecreatefrombmp: Can not open %s!','imsanity') , $filename ), E_USER_WARNING );
			return false;
		}
		// read file header
		$meta = unpack('vtype/Vfilesize/Vreserved/Voffset', fread( $fh, 14 ) );
		// check for bitmap
		if ($meta['type'] != 19778) {
			trigger_error( sprintf( __( 'imagecreatefrombmp: %s is not a bitmap!', 'imsanity' ), $filename ), E_USER_WARNING );
			return false;
		}
		// read image header
		$meta += unpack('Vheadersize/Vwidth/Vheight/vplanes/vbits/Vcompression/Vimagesize/Vxres/Vyres/Vcolors/Vimportant', fread($fh, 40));
		// read additional 16bit header
		if ($meta['bits'] == 16) {
			$meta += unpack('VrMask/VgMask/VbMask', fread($fh, 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( sprintf( __( 'imagecreatefrombmp: Cannot obtain filesize of %s !', 'imsanity' ), $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;
				}
			}
		}
		// create gd image
		$im = imagecreatetruecolor($meta['width'], $meta['height']);
		$data = fread($fh, $meta['imagesize']);
		$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);
						$color[1] = (($color[1] & 0xf800) >> 8) * 65536 + (($color[1] & 0x07e0) >> 3) * 256 + (($color[1] & 0x001f) << 3);
						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] & 0x0F;
						$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( sprintf( __( 'imagecreatefrombmp: %s has %d bits and this is not supported!', 'imsanity' ), $filename, $meta['bits'] ), E_USER_WARNING );
						return false;
				}
				imagesetpixel($im, $x, $y, $color[1]);
				$x++;
				$p += $meta['bytes'];
			}
			$y--;
			$p += $meta['decal'];
		}
		fclose($fh);
		return $im;
	}
}

?>
