PHP之生成GIF动画的实现方法

<?
class GifMerge {
??? var $ver??????????? = '1.1';
??? var $dly??????????? = 50;
??? var $mod??????????? = 'C_FILE';
??? var $first??????????? = true;
??? var $use_loop??????????? = false;
??? var $transparent??????? = false;
??? var $use_global_in??????? = false;
??? var $x??????????????? = 0;
??? var $y??????????????? = 0;
??? var $ch??????????????? = 0;
??? var $fin??????????? = 0;
??? var $fout??????????? = '';
??? var $loop??????????? = 0;
??? var $delay??????????? = 0;
??? var $width??????????? = 0;
??? var $height??????????? = 0;
??? var $trans1???????????? = 255;
??? var $trans2???????????? = 255;
??? var $trans3???????????? = 255;
??? var $disposal??????????? = 2;
??? var $out_color_table_size??? = 0;
??? var $local_color_table_flag??? = 0;
??? var $global_color_table_size??? = 0;
??? var $out_color_table_sizecode??? = 0;
??? var $global_color_table_sizecode= 0;
??? var $gif??????????? = array(0x47, 0x49, 0x46);
??? var $buffer??????????? = array();
??? var $local_in??????????? = array();
??? var $global_in??????????? = array();
??? var $global_out??????????? = array();
??? var $logical_screen_descriptor??? = array();
??? function GifMerge($images, $t1, $t2, $t3, $loop, $dl, $xpos, $ypos, $model) {
??????? if($model) {
??????????? $this->mod = $model;
??????? }
??????? if($loop > -1) {
??????????? $this->loop = floor($loop - 1);
??????????? $this->use_loop = true;
??????? }
??????? if($t1 > -1 && $t2 > -1 && $t3 > -1) {
??????????? $this->trans1 = $t1;
??????????? $this->trans2 = $t2;
??????????? $this->trans3 = $t3;
??????????? $this->transparent = true;
??????? }
??????? for($i = 0; $i < count($images); $i++) {
??????????? $dl[$i]??? ? $this->delay = $dl[$i] : $this->delay = $this->dly;
??????????? $xpos[$i] ? $this->x = $xpos[$i] : $this->x = 0;
??????????? $ypos[$i] ? $this->y = $ypos[$i] : $this->y = 0;
??????????? $this->start_gifmerge_process($images[$i]);
??????? }
??????? $this->fout .= "/x3b";
??? }
??? function start_gifmerge_process($fp) {
??????? if($this->mod == 'C_FILE') {
??????????? if(!$this->fin = fopen($fp, 'rb')) {
??????????????? return;
??????????? }
??????? } elseif($this->mod == 'C_MEMORY') {
??????????? $this->ch = 0;
??????????? $this->fin = $fp;
??????? }
??????? $this->getbytes(6);
??????? if(!$this->arrcmp($this->buffer, $this->gif, 3)) {
??????????? return;
??????? }
??????? $this->getbytes(7);
??????? if($this->first) $this->logical_screen_descriptor = $this->buffer;
??????? $this->global_color_table_sizecode = $this->buffer[4] & 0x07;
??????? $this->global_color_table_size = 2 << $this->global_color_table_sizecode;
??????? if($this->buffer[4] & 0x80) {
??????????? $this->getbytes((3 * $this->global_color_table_size));
??????????? for($i = 0; $i < ((3 * $this->global_color_table_size)); $i++) {
??????????????? $this->global_in[$i] = $this->buffer[$i];
??????????? }
??????????? if($this->out_color_table_size == 0) {
??????????????? $this->out_color_table_size = $this->global_color_table_size;
??????????????? $out_color_table_sizecode = $this->global_color_table_sizecode;
??????????????? $this->global_out = $this->global_in;
??????????? }
??????????? if($this->global_color_table_size != $this->out_color_table_size || $this->arrcmp($this->global_out, $this->global_in, (3 * $this->global_color_table_size))) {
??????????????? $this->use_global_in = true;
??????????? }
??????? }
??????? for($loop = true; $loop;) {
??????????? $this->getbytes(1);
??????????? switch($this->buffer[0]) {
??????????????? case 0x21:
??????????????????? $this->read_extension();
??????????????????? break;
??????????????? case 0x2c:
??????????????????? $this->read_image_descriptor();
??????????????????? break;
??????????????? case 0x3b:
??????????????????? $loop = false;
??????????????? break;
??????????????? default:
??????????????????? $loop = false;
??????????? }
??????? }
??????? if($this->mod == 'C_FILE') {
??????????? fclose($this->fin);
??????? }
??? }
??? function read_image_descriptor() {
??????? $this->getbytes(9);
??????? $head = $this->buffer;
??????????? $this->local_color_table_flag = ($this->buffer[8] & 0x80) ? true : false;
??????????? if($this->local_color_table_flag) {
??????????? $sizecode = $this->buffer[8] & 0x07;
??????????? $size = 2 << $sizecode;
??????????? $this->getbytes(3 * $size);
??????????? for($i = 0; $i < (3 * $size); $i++) {
??????????????????? $this->local_in[$i] = $this->buffer[$i];
??????????????? }
??????????????? if($this->out_color_table_size == 0) {
??????????????????? $this->out_color_table_size = $size;
??????????????????? $out_color_table_sizecode = $sizecode;
??????????????? for($i = 0; $i < (3 * $size); $i++)
??????????????? {
??????????????????? $this->global_out[$i] = $this->local_in[$i];
??????????????? }
??????????????? }
??????????? }
??????????? if($this->first) {
??????????? $this->first = false;
??????????? $this->fout .= "/x47/x49/x46/x38/x39/x61";
??????????? if($this->width && $this->height) {
??????????????? $this->logical_screen_descriptor[0] = $this->width & 0xFF;
??????????????? $this->logical_screen_descriptor[1] = ($this->width & 0xFF00) >> 8;
??????????????? $this->logical_screen_descriptor[2] = $this->height & 0xFF;
??????????????? $this->logical_screen_descriptor[3] = ($this->height & 0xFF00) >> 8;
??????????? }
??????????? $this->logical_screen_descriptor[4] |= 0x80;
??????????? $this->logical_screen_descriptor[5] &= 0xF0;
??????????? $this->logical_screen_descriptor[6] |= $this->out_color_table_sizecode;
??????????? $this->putbytes($this->logical_screen_descriptor, 7);
??????????????? $this->putbytes($this->global_out, ($this->out_color_table_size * 3));
??????????? if($this->use_loop) {
??????????????? $ns[0] = 0x21;
??????????????? $ns[1] = 0xFF;
??????????????? $ns[2] = 0x0B;
??????????????? $ns[3] = 0x4e;
??????????????? $ns[4] = 0x45;
??????????????? $ns[5] = 0x54;
??????????????? $ns[6] = 0x53;
??????????????? $ns[7] = 0x43;
??????????????? $ns[8] = 0x41;
??????????????? $ns[9] = 0x50;
??????????????? $ns[10] = 0x45;
??????????????? $ns[11] = 0x32;
??????????????? $ns[12] = 0x2e;
??????????????? $ns[13] = 0x30;
??????????????? $ns[14] = 0x03;
??????????????? $ns[15] = 0x01;
??????????????? $ns[16] = $this->loop & 255;
??????????????????? $ns[17] = $this->loop >> 8;
??????????????? $ns[18] = 0x00;
??????????????? $this->putbytes($ns, 19);
??????????? }
??????????? }
????????? if($this->use_global_in) {
??????????? $outtable = $this->global_in;
??????????? $outsize = $this->global_color_table_size;
??????????? $outsizecode = $this->global_color_table_sizecode;
??????? } else {
??????????? $outtable = $this->global_out;
??????????? $outsize = $this->out_color_table_size;
??????? }
??????? if($this->local_color_table_flag) {
??????????? if($size == $this->out_color_table_size && !$this->arrcmp($this->local_in, $this->global_out, $size)) {
??????????????? $outtable = $global_out;
??????????????? $outsize = $this->out_color_table_size;
??????????? } else {
??????????????? $outtable = $this->local_in;
??????????????? $outsize = $size;
??????????????? $outsizecode = $sizecode;
??????????? }
??????? }
??????? $use_trans = false;
??????? if($this->transparent) {
??????????? for($i = 0; $i < $outsize; $i++) {
??????????????? if($outtable[3 * $i] == $this->trans1 && $outtable [3 * $i + 1] == $this->trans2 && $outtable [3 * $i + 2] == $this->trans3) {
??????????????????? break;
??????????????? }
??????????? }
??????????? if($i < $outsize) {
??????????????? $transindex = $i;
??????????????? $use_trans = true;
??????????? }
??????? }
??????? if($this->delay || $use_trans) {
??????????? $this->buffer[0] = 0x21;
??????????? $this->buffer[1] = 0xf9;
??????????? $this->buffer[2] = 0x04;
??????????? $this->buffer[3] = ($this->disposal << 2) + ($use_trans ? 1 : 0);
??????????? $this->buffer[4] = $this->delay & 0xff;
??????????? $this->buffer[5] = ($this->delay & 0xff00) >> 8;
??????????? $this->buffer[6] = $use_trans ? $transindex : 0;
??????????? $this->buffer[7] = 0x00;
??????????? $this->putbytes($this->buffer,8);
??????? }
??????? $this->buffer[0] = 0x2c;
??????? $this->putbytes($this->buffer,1);
??????? $head[0] = $this->x & 0xff;
??????? $head[1] = ($this->x & 0xff00) >> 8;
??????? $head[2] = $this->y & 0xff;
??????? $head[3] = ($this->y & 0xff00) >> 8;
??????? $head[8] &= 0x40;
??????? if($outtable != $this->global_out) {
??????????? $head[8] |= 0x80;
??????????? $head[8] |= $outsizecode;
??????? }
??????? $this->putbytes($head,9);
??????? if($outtable != $this->global_out) {
??????????? $this->putbytes($outtable, (3 * $outsize));
??????? }
??????? $this->getbytes(1);
??????? $this->putbytes($this->buffer,1);
??????? for(;;) {
??????????? $this->getbytes(1);
??????????? $this->putbytes($this->buffer,1);
??????????? if(($u = $this->buffer[0]) == 0) {
??????????????? break;
??????????? }
??????????? $this->getbytes($u);
??????????? $this->putbytes($this->buffer, $u);
??????????? }
??? }
??? function read_extension() {
??????? $this->getbytes(1);
??????? switch($this->buffer[0]) {
??????????? case 0xf9:
??????????????????? $this->getbytes(6);
?????????????????? break;
??????????? case 0xfe:
??????????????????? for(;;) {
??????????????????? $this->getbytes(1);
??????????????????????????? if(($u = $this->buffer[0]) == 0) {
??????????????????????????? break;
??????????????????????? }
??????????????????? $this->getbytes($u);
??????????????????? }
??????????????? break;
??????????? case 0x01:
??????????????????? $this->getbytes(13);
??????????????????? for(;;) {
??????????????????? $this->getbytes(0);
??????????????????????????? if(($u = $this->buffer[0]) == 0) {
??????????????????????????? break;
??????????????????????? }
??????????????????? $this->getbytes($u);
??????????????????? }
??????????????? break;
?????????????????? case 0xff:
??????????????????? $this->getbytes(9);
??????????????????? $this->getbytes(3);
??????????????????? for(;;) {
??????????????????? $this->getbytes(1);
??????????????????????????? if(!$this->buffer[0]) {
??????????????????????????????? break;
??????????????????????????? }
??????????????????????????? $this->getbytes($this->buffer[0]);
??????????????????????? }
??????????????? break;
??????????? default:
??????????????????? for(;;) {
??????????????????? $this->getbytes(1);
??????????????????????? if(!$this->buffer[0]) {
??????????????????????????? break;
??????????????????????? }
??????????????????? $this->getbytes($this->buffer[0]);
??????????????? }
??????????? }
??? }
??? function arrcmp($b, $s, $l) {
??????? for($i = 0; $i < $l; $i++) {
??????????? if($s{$i} != $b{$i}) {
??????????????? return false;
??????????? }
??????? }
??????? return true;
??? }
??? function getbytes($l) {
??????? for($i = 0; $i < $l; $i++) {
??????????? if($this->mod == 'C_FILE') {
??????????????????? $bin = unpack('C*', fread($this->fin, 1));
??????????????????? $this->buffer[$i] = $bin[1];
??????????????? } elseif($this->mod == 'C_MEMORY') {
??????????????????????? $bin = unpack('C*', substr($this->fin, $this->ch, 1));
??????????????????????? $this->buffer[$i] = $bin[1];
??????????????????????? $this->ch++;
??????????????? }
??????? }
??????? return $this->buffer;
??? }
??? function putbytes($s, $l) {
??????? for($i = 0; $i < $l; $i++) {
??????????? $this->fout .= pack('C*', $s[$i]);
??????? }
??? }
??? function getAnimation() {
??????? return $this->fout;
??? }
}
?>