<?php namespace ProcessWire;

/*
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::
::    ISEAG_GIFEncoder Version 2.0 by László Zsidi, http://gifs.hu
::
::    This class is a rewritten 'GifMerge.class.php' version.
::
::  Modification:
::   - Simplified and easy code,
::   - Ultra fast encoding,
::   - Built-in errors,
::   - Stable working
::
::
::    Updated at 2007. 02. 13. '00.05.AM'
::
::  * Enhanced version by xurei (https://github.com/xurei/GIFDecoder_optimized)
::
::  Try on-line GIFBuilder Form demo based on ISEAG_GIFEncoder.
::
::  http://gifs.hu/phpclasses/demos/GifBuilder/
:: 
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

LICENSE: 
  All versions specify Apache 2.0 license (2018-01-31): 
  https://github.com/jacoka/GIFDecoder/blob/master/LICENSE
  https://github.com/xurei/GIFDecoder_optimized/blob/master/LICENSE

Namespace added by Horst for ProcessWire

*/

class ISEAG_GIFEncoder {
    var $GIF = "GIF89a";        /* GIF header 6 bytes    */
    var $VER = "ISEAG_GIFEncoder V2.05";    /* Encoder version        */

    var $BUF = Array ( );
    var $LOP =  0;
    var $DIS =  2;
    //var $COL = -1;
    var $TRANSPARENT_R = -1;
    var $TRANSPARENT_G = -1;
    var $TRANSPARENT_B = -1;
    var $IMG = -1;

    var $ERR = Array (
        'ERR00'=>"Does not supported function for only one image!",
        'ERR01'=>"Source is not a GIF image!",
        'ERR02'=>"Unintelligible flag ",
        'ERR03'=>"Does not make animation from animated GIF source",
    );

    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    ISEAG_GIFEncoder...
    ::
    */
    function __construct    (
                            $GIF_src, $GIF_dly, $GIF_lop, $GIF_dis,
                            $GIF_red, $GIF_grn, $GIF_blu, $GIF_mod
                        ) {
        if ( ! is_array ( $GIF_src ) && ! is_array ( $GIF_dly ) ) {
            printf    ( "%s: %s", $this->VER, $this->ERR [ 'ERR00' ] );
            exit    ( 0 );
        }
        $this->LOP = ( $GIF_lop > -1 ) ? $GIF_lop : 0;

        $GIF_dis_out = $GIF_dis;
        foreach ($GIF_dis_out as &$dis)
        {
            $dis = ( $dis > -1 ) ? ( ( $dis < 3 ) ? $dis : 3 ) : 2;
        }

        $this->DIS = $GIF_dis_out;//( $GIF_dis > -1 ) ? ( ( $GIF_dis < 3 ) ? $GIF_dis : 3 ) : 2;
        /*$this->COL = ( $GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1 ) ?
                        ( $GIF_red | ( $GIF_grn << 8 ) | ( $GIF_blu << 16 ) ) : -1;*/
        if ( $GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1 )
        {
            $this->TRANSPARENT_R = $GIF_red & 0xFF;
            $this->TRANSPARENT_G = $GIF_grn & 0xFF;
            $this->TRANSPARENT_B = $GIF_blu & 0xFF;
        }

        //Filling in the buffer
        for ( $i = 0; $i < count ( $GIF_src ); $i++ ) {
            if ( strToLower ( $GIF_mod ) == "url" ) {
                $this->BUF [ ] = fread ( fopen ( $GIF_src [ $i ], "rb" ), filesize ( $GIF_src [ $i ] ) );
            }
            else if ( strToLower ( $GIF_mod ) == "bin" ) {
                $this->BUF [ ] = $GIF_src [ $i ];
            }
            else {
                printf    ( "%s: %s ( %s )!", $this->VER, $this->ERR [ 'ERR02' ], $GIF_mod );
                exit    ( 0 );
            }
            if ( substr ( $this->BUF [ $i ], 0, 6 ) != "GIF87a" && substr ( $this->BUF [ $i ], 0, 6 ) != "GIF89a" ) {
                printf    ( "%s: %d %s", $this->VER, $i, $this->ERR [ 'ERR01' ] );
                exit    ( 0 );
            }
            for ( $j = ( 13 + 3 * ( 2 << ( ord ( $this->BUF [ $i ] [ 10 ] ) & 0x07 ) ) ), $k = TRUE; $k; $j++ ) {
                switch ( $this->BUF [ $i ] [ $j ] ) {
                    case "!":
                        if ( ( substr ( $this->BUF [ $i ], ( $j + 3 ), 8 ) ) == "NETSCAPE" ) {
                            printf    ( "%s: %s ( %s source )!", $this->VER, $this->ERR [ 'ERR03' ], ( $i + 1 ) );
                            exit    ( 0 );
                        }
                        break;
                    case ";":
                        $k = FALSE;
                        break;
                }
            }
        }
        ISEAG_GIFEncoder::GIFAddHeader ( );
        for ( $i = 0; $i < count ( $this->BUF ); $i++ ) {
            ISEAG_GIFEncoder::GIFAddFrames ( $i, $GIF_dly[$i] );
        }
        ISEAG_GIFEncoder::GIFAddFooter ( );
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFAddHeader...
    ::
    */
    function GIFAddHeader ( ) {
        $cmap = 0;

        if ( ord ( $this->BUF [ 0 ] [ 10 ] ) & 0x80 ) {
            $cmap = 3 * ( 2 << ( ord ( $this->BUF [ 0 ] [ 10 ] ) & 0x07 ) );

            $this->GIF .= substr ( $this->BUF [ 0 ], 6, 7        );
            $this->GIF .= substr ( $this->BUF [ 0 ], 13, $cmap    );
            $this->GIF .= "!\377\13NETSCAPE2.0\3\1" . ISEAG_GIFEncoder::GIFWord ( $this->LOP ) . "\0";
        }
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFAddFrames...
    ::
    */
    function GIFAddFrames ( $i, $d ) {

        $Locals_str = 13 + 3 * ( 2 << ( ord ( $this->BUF [ $i ] [ 10 ] ) & 0x07 ) );

        $Locals_end = strlen ( $this->BUF [ $i ] ) - $Locals_str - 1;
        $Locals_tmp = substr ( $this->BUF [ $i ], $Locals_str, $Locals_end );

        $Global_len = 2 << ( ord ( $this->BUF [ 0  ] [ 10 ] ) & 0x07 );
        $Locals_len = 2 << ( ord ( $this->BUF [ $i ] [ 10 ] ) & 0x07 );

        $Global_rgb = substr ( $this->BUF [ 0  ], 13,
                            3 * ( 2 << ( ord ( $this->BUF [ 0  ] [ 10 ] ) & 0x07 ) ) );
        $Locals_rgb = substr ( $this->BUF [ $i ], 13,
                            3 * ( 2 << ( ord ( $this->BUF [ $i ] [ 10 ] ) & 0x07 ) ) );

        $Locals_ext = "!\xF9\x04" . chr ( ( $this->DIS[$i] << 2 ) + 0 ) .
                        chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . "\x0\x0";
        $Locals_img = '';

        if ( $this->TRANSPARENT_R > -1 && ord ( $this->BUF [ $i ] [ 10 ] ) & 0x80 ) {
            for ( $j = 0; $j < ( 2 << ( ord ( $this->BUF [ $i ] [ 10 ] ) & 0x07 ) ); $j++ ) {
                if (
                ord ( $Locals_rgb [ 3 * $j + 0 ] ) == $this->TRANSPARENT_R &&
                ord ( $Locals_rgb [ 3 * $j + 1 ] ) == $this->TRANSPARENT_G &&
                ord ( $Locals_rgb [ 3 * $j + 2 ] ) == $this->TRANSPARENT_B )
                {
                    $Locals_ext = "!\xF9\x04" . chr ( ( $this->DIS[$i] << 2 ) ) .
                    chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . chr ( $j ) . "\x0";
                    break;
                }
            }
        }
        switch ( $Locals_tmp [ 0 ] ) {
            case "!":
                $Locals_img = substr ( $Locals_tmp, 8, 10 );
                $Locals_ext[3] = chr((ord($Locals_ext[3]) & 0xFE) | (ord($Locals_tmp[3]) & 0x01));
                $Locals_tmp = substr ( $Locals_tmp, 18, strlen ( $Locals_tmp ) - 18 );
                break;
            case ",":
                $Locals_img = substr ( $Locals_tmp, 0, 10 );
                $Locals_tmp = substr ( $Locals_tmp, 10, strlen ( $Locals_tmp ) - 10 );
                break;
        }
        if ( ord ( $this->BUF [ $i ] [ 10 ] ) & 0x80 && $this->IMG > -1 ) {
            if ( $Global_len == $Locals_len ) {
                if ( ISEAG_GIFEncoder::GIFBlockCompare ( $Global_rgb, $Locals_rgb, $Global_len ) ) {
                    $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );
                }
                else {
                    $byte  = ord ( $Locals_img [ 9 ] );
                    $byte |= 0x80;
                    $byte &= 0xF8;
                    $byte |= ( ord ( $this->BUF [ 0 ] [ 10 ] ) & 0x07 );
                    $Locals_img [ 9 ] = chr ( $byte );
                    $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
                }
            }
            else {
                $byte  = ord ( $Locals_img [ 9 ] );
                $byte |= 0x80;
                $byte &= 0xF8;
                $byte |= ( ord ( $this->BUF [ $i ] [ 10 ] ) & 0x07 );
                $Locals_img [ 9 ] = chr ( $byte );
                $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
            }
        }
        else {
            $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );
        }
        $this->IMG  = 1;
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFAddFooter...
    ::
    */
    function GIFAddFooter ( ) {
        $this->GIF .= ";";
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFBlockCompare...
    ::
    */
    function GIFBlockCompare ( $GlobalBlock, $LocalBlock, $Len ) {

        for ( $i = 0; $i < $Len; $i++ ) {
            if    (
                    $GlobalBlock [ 3 * $i + 0 ] != $LocalBlock [ 3 * $i + 0 ] ||
                    $GlobalBlock [ 3 * $i + 1 ] != $LocalBlock [ 3 * $i + 1 ] ||
                    $GlobalBlock [ 3 * $i + 2 ] != $LocalBlock [ 3 * $i + 2 ] 
                ) {
                    return ( 0 );
            }
        }

        return ( 1 );
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFWord...
    ::
    */
    function GIFWord ( $int ) {

        return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) );
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GetAnimation...
    ::
    */
    function GetAnimation ( ) {
        return ( $this->GIF );
    }
}