public function generate()
{
$width = $this->_owner->getImageWidth();
$height = $this->_owner->getImageHeight();
// default values
$checkTransparency = false;
// define borders to trim away
if (is_null($this->_away)) {
$this->_away = array('top', 'right', 'bottom', 'left');
} elseif (is_string($this->_away)) {
$this->_away = array($this->_away);
}
// lower border names
foreach ($this->_away as $key => $value) {
$this->_away[$key] = strtolower($value);
}
// define base color position
switch (strtolower($this->_base)) {
case 'transparent':
case 'trans':
$checkTransparency = true;
$base_x = 0;
$base_y = 0;
break;
case 'bottom-right':
case 'right-bottom':
$base_x = $width - 1;
$base_y = $height - 1;
break;
default:
case 'top-left':
case 'left-top':
$base_x = 0;
$base_y = 0;
break;
}
// pick base color
if ($checkTransparency) {
// color will only be used to compare alpha channel
$color = array('red' => 255, 'green' => 255, 'blue' => 255, 'alpha' => 0);
} else {
$color = Color::intColorToArrayColor($this->_owner->imageColorAt($base_x, $base_y));
}
$top_x = 0;
$top_y = 0;
$bottom_x = $width;
$bottom_y = $height;
// search upper part of image for colors to trim away
if (in_array('top', $this->_away)) {
for ($y = 0; $y < ceil($height / 2); $y++) {
for ($x = 0; $x < $width; $x++) {
$checkColor = Color::intColorToArrayColor($this->_owner->imageColorAt($x, $y));
if ($checkTransparency) {
$checkColor['red'] = $color['red'];
$checkColor['green'] = $color['green'];
$checkColor['blue'] = $color['blue'];
}
if (Color::differs($color, $checkColor, $this->_tolerance)) {
$top_y = max(0, $y - $this->_feather);
break 2;
}
}
}
}
// search left part of image for colors to trim away
if (in_array('left', $this->_away)) {
for ($x = 0; $x < ceil($width / 2); $x++) {
for ($y = $top_y; $y < $height; $y++) {
$checkColor = Color::intColorToArrayColor($this->_owner->imageColorAt($x, $y));
if ($checkTransparency) {
$checkColor['red'] = $color['red'];
$checkColor['green'] = $color['green'];
$checkColor['blue'] = $color['blue'];
}
if (Color::differs($color, $checkColor, $this->_tolerance)) {
$top_x = max(0, $x - $this->_feather);
break 2;
}
}
}
}
// search lower part of image for colors to trim away
if (in_array('bottom', $this->_away)) {
for ($y = $height - 1; $y >= floor($height / 2) - 1; $y--) {
for ($x = $top_x; $x < $width; $x++) {
$checkColor = Color::intColorToArrayColor($this->_owner->imageColorAt($x, $y));
if ($checkTransparency) {
$checkColor['red'] = $color['red'];
$checkColor['green'] = $color['green'];
$checkColor['blue'] = $color['blue'];
}
if (Color::differs($color, $checkColor, $this->_tolerance)) {
$bottom_y = min($height, $y + 1 + $this->_feather);
break 2;
}
}
}
}
// search right part of image for colors to trim away
if (in_array('right', $this->_away)) {
for ($x = $width - 1; $x >= floor($width / 2) - 1; $x--) {
for ($y = $top_y; $y < $bottom_y; $y++) {
$checkColor = Color::intColorToArrayColor($this->_owner->imageColorAt($x, $y));
if ($checkTransparency) {
$checkColor['red'] = $color['red'];
$checkColor['green'] = $color['green'];
$checkColor['blue'] = $color['blue'];
}
if (Color::differs($color, $checkColor, $this->_tolerance)) {
$bottom_x = min($width, $x + 1 + $this->_feather);
break 2;
}
}
}
}
$trimmed = new Canvas();
$trimmed->createImageTrueColorTransparent($bottom_x - $top_x, $bottom_y - $top_y);
// Preserve transparency
$transIndex = imagecolortransparent($this->_owner->image);
if ($transIndex != -1) {
$rgba = imagecolorsforindex($trimmed->image, $transIndex);
$transColor = imagecolorallocatealpha($trimmed->image, $rgba['red'], $rgba['green'], $rgba['blue'], 127);
imagefill($trimmed->image, 0, 0, $transColor);
imagecolortransparent($trimmed->image, $transColor);
} else {
imagealphablending($trimmed->image, false);
imagesavealpha($trimmed->image, true);
}
imagecopyresampled($trimmed->image, $this->_owner->image, 0, 0, $top_x, $top_y, $bottom_x - $top_x, $bottom_y - $top_y, $bottom_x - $top_x, $bottom_y - $top_y);
$this->_owner->image = $trimmed->image;
return true;
}
