<?php
/*
Animated PNG Creator
Version: 1.6.2
Licence: GNU Lesser General Public License
http://www.gnu.org/licenses/lgpl.html
Feedback, bug report, feature request: apng@zoznam.sk
*/
class APNG_Creator {
/*
The array containing the animation frames and it's properties.
Data structure:
$images[i] : array(
IMAGE => a GD resource of an image,
DELAY => the delay fraction before displaying the frame (in seconds) : array(
[0] => numerator,
[1] => denominator
),
DISPOSE => specifies how the output buffer should be changed at the end of the delay (before rendering the next frame)
BLEND => specifies whether the frame is to be alpha blended into the current output buffer content, or whether it should completely replace its region in the output buffer
)
*/
protected $gd_data = null;
protected $images = array();
// Contains the width and the height of the image, respectively the biggest dimensions in the animation.
protected $image_data = array();
public $save_alpha = true;
public $save_time = false;
// Defines the play count for the animation. Value 0 (zero) means infinite playing.
public $play_count = 0;
public $background_color = array(255, 255, 255, 127);
public $transparent_color = false;
// The PNG signature
const SIGNATURE = "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A";
// Format strings for the pack() and unpack() functions representing some APNG chunk datas.
// To understant this formats please read the APNG specification.
const IHDR_data = "NNCCCCC";
const acTL_data = "NN";
const fcTL_data = "NNNNNnncc";
const tIME = "nccccc";
// The version of the class.
const VERSION = "1.6.2";
function APNG_Creator() {
$this->gd_data = gd_info();
}
/*
Returns IDAT chunk's data fields.
*/
protected function get_png_idat_data($img) {
ob_start();
imagepng($img, null);
$data = ob_get_contents();
$idat_data = "";
$chunk_data = "";
$idat_offset = 0;
ob_end_clean();
// There can be more IDAT chunks!!!
do {
$idat_offset = strpos($data, "IDAT", $idat_offset);
if ($idat_offset === false) return $idat_data;
$chunk_data = substr($data, $idat_offset - 4);
$chunk = unpack("Nlength", $chunk_data);
$chunk_data = substr($chunk_data, 8, $chunk['length']);
$idat_data .= $chunk_data;
$idat_offset += 4;
} while ($idat_offset !== false);
return $idat_data;
}
/*
$name : the name of the chunk (for example IDAT, fdAT, tEXt, ...)
$data : the data fields of the chunk
Returns a complete chunk, in the standard format:
Length (4 bytes) - Name (4 bytes) - Data (length bytes) - CRC (4 bytes)
*/
protected function complete_chunk($name, $data) {
$name_data = $name . $data;
return (pack("N", strlen($data)) . $name_data . pack("N", crc32($name_data)));
}
/*
Calculates the x and y offsets of a frame regarding to the buffer (see documentation).
The values are returned in an array.
*/
protected function calculate_position($image, $position = "MIDDLE_CENTER") {
$x = imagesx($image);
$y = imagesy($image);
if (!(is_array($position))) {
switch ($position) {
case "TOP_LEFT":
$position = array(0, 0);
break;
case "TOP_CENTER":
$position = array(($this->image_data['WIDTH'] - $x) / 2, 0);
break;
case "TOP_RIGHT":
$position = array($this->image_data['WIDTH'] - $x, 0);
break;
case "BOTTOM_LEFT":
$position = array(0, $this->image_data['HEIGHT'] - $y);
break;
case "BOTTOM_CENTER":
$position = array(($this->image_data['WIDTH'] - $x) / 2, $this->image_data['HEIGHT'] - $y);
break;
case "BOTTOM_RIGHT":
$position = array($this->image_data['WIDTH'] - $x, $this->image_data['HEIGHT'] - $y);
break;
case "MIDDLE_LEFT":
$position = array(0, ($this->image_data['HEIGHT'] - $y) / 2);
break;
case "MIDDLE_RIGHT":
$position = array($this->image_data['WIDTH'] - $x, ($this->image_data['HEIGHT'] - $y) / 2);
break;
case "MIDDLE_CENTER":
default:
$position = array(($this->image_data['WIDTH'] - $x) / 2, ($this->image_data['HEIGHT'] - $y) / 2);
}
}
if ($position[0] + $x > $this->image_data['WIDTH']) $position[0] = $this->image_data['WIDTH'] - $x;
if ($position[0] < 0) $position[0] = 0;
if ($position[1] + $y > $this->image_data['HEIGHT']) $position[1] = $this->image_data['HEIGHT'] - $y;
if ($position[1] < 0) $position[1] = 0;
$position[0] = intval($position[0]);
$position[1] = intval($position[1]);
return $position;
}
public function destroy_images() {
foreach ($this->images as $frame) {
imagedestroy($frame['IMAGE']);
}
}
public function add_image($img, $position = "MIDDLE_CENTER", $delay = 1000, $dispose_op = 0, $blend_op = 0, $part_of_anim = true) {
$width = imagesx($img);
$height = imagesy($img);
if (!($width > 0 && $height > 0)) return false;
if (!(is_array($delay))) {
$delay = array(
intval($delay),
1000
);
}
$dispose_options = array("APNG_DISPOSE_OP_NONE", "APNG_DISPOSE_OP_BACKGROUND", "APNG_DISPOSE_OP_PREVIOUS");
$blend_options = array("APNG_BLEND_OP_SOURCE", "APNG_BLEND_OP_OVER");
if (is_string($dispose_op)) $dispose_op = array_search($dispose_op, $dispose_options);
if (is_string($blend_op)) $blend_op = array_search($blend_op, $blend_options);
$is_default_image = (count($this->images) === 0);
$this->images[] = array(
"IMAGE" => $img,
"DELAY" => $delay,
"DISPOSE" => intval($dispose_op) % 3,
"BLEND" => intval($blend_op) % 2,
"POSITION" => $position,
"PART_OF_ANIM" => (!($is_default_image && (! $part_of_anim)))
);
if (!isset($this->image_data['WIDTH']) || $width > $this->image_data['WIDTH']) $this->image_data['WIDTH'] = $width;
if (!isset($this->image_data['HEIGHT']) || $height > $this->image_data['HEIGHT']) $this->image_data['HEIGHT'] = $height;
return true;
}
/*
$filename : the filename of the output file
Saves the animation.
*/
public function save($filename = "") {
$fp = fopen($filename, "w");
if (! $fp) return false;
$out = "";
$out .= self::SIGNATURE;
// IHDR
$out .= $this->complete_chunk("IHDR", pack(self::IHDR_data, $this->image_data['WIDTH'], $this->image_data['HEIGHT'], 8, ($this->save_alpha ? 6 : 2), 0, 0, 0));
// Metadata (tEXt) - Please don't remove this sequence of the code! It is necessary for debugging!
$out .= $this->complete_chunk("tEXt", "Software" . chr(0) . "Animated PNG Creator v" . self::VERSION . " (www.phpclasses.org)");
$out .= $this->complete_chunk("tEXt", "Technical informations" . chr(0) . phpversion() . "; " . $this->gd_data['GD Version']);
// Saving time data
if ($this->save_time) {
$out .= $this->complete_chunk("tEXt", "Creation Time" . chr(0) . date("D, d M Y H:i:s O"));
}
// tRNS - transparent color
if ($this->transparent_color && !($this->save_alpha)) {
$out .= $this->complete_chunk("tRNS", pack("nnn", $this->transparent_color[0], $this->transparent_color[1], $this->transparent_color[2]));
}
// acTL
$out .= $this->complete_chunk("acTL", pack(self::acTL_data, count($this->images), abs(intval($this->play_count))));
fwrite($fp, $out);
$sequence_number = 0;
$is_default_image = true;
foreach ($this->images as $frame) {
$image = $frame['IMAGE'];
$x = imagesx($image);
$y = imagesy($image);
$position = $this->calculate_position($image, $frame['POSITION']);
$destroy_image = false;
$is_tc = imageistruecolor($image);
/*
According to the APNG specification the default image can't be positioned via the fcTL
x_offset and y_offset properties. So the script in case of the default image
creates a new resized frame, fills it with the specified background (default color is fully
transparent - if the save_alpha option is set to true) and copyes the frame to it's position.
*/
$align_needed = ($is_default_image && ($x < $this->image_data['WIDTH'] || $y < $this->image_data['HEIGHT']));
if ((! $is_tc) || $align_needed) {
if ($align_needed) {
$i2x = $this->image_data['WIDTH'];
$i2y = $this->image_data['HEIGHT'];
$i2_offsx = ($this->image_data['WIDTH'] - $x) / 2;
$i2_offsy = ($this->image_data['HEIGHT'] - $y) / 2;
$position = array(0, 0);
} else {
$i2x = $x;
$i2y = $y;
$i2_offsx = 0;
$i2_offsy = 0;
}
$image2 = imagecreatetruecolor($i2x, $i2y);
$bckg = imagecolorallocatealpha($image2, $this->background_color[0], $this->background_color[1], $this->background_color[2], $this->background_color[3]);
imagefill($image2, 0, 0, $bckg);
imagecopy($image2, $image, $i2_offsx, $i2_offsy, 0, 0, $x, $y);
$image = $image2;
$x = $i2x;
$y = $i2y;
$destroy_image = true;
}
imagesavealpha($image, !(!($this->save_alpha)));
$out = "";
// fcTL
if ($frame['PART_OF_ANIM']) {
$out .= $this->complete_chunk("fcTL", pack(self::fcTL_data, $sequence_number, $x, $y, $position[0], $position[1], $frame['DELAY'][0], $frame['DELAY'][1], $frame['DISPOSE'], $frame['BLEND']));
$sequence_number++;
}
// IDAT, fdAT
if ($is_default_image) {
$out .= $this->complete_chunk("IDAT", $this->get_png_idat_data($image));
} else {
$out .= $this->complete_chunk("fdAT", pack("N", $sequence_number) . $this->get_png_idat_data($image));
$sequence_number++;
}
fwrite($fp, $out);
if ($destroy_image) imagedestroy($image);
$is_default_image = false;
}
$IEND = $this->complete_chunk("IEND", "");
fwrite($fp, $IEND);
fclose($fp);
}
}
?>
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