/**
* Applies the sepia filter to an image resource
*
* @param ImageResource $aResource
*/
public function applyFilter(ImageResource $aResource)
{
if ($this->degrees === 0) {
return;
}
$width = $aResource->getX();
$height = $aResource->getY();
// cache calculated colors in a map...
$colorMap = array();
for ($x = 0; $x < $width; ++$x) {
for ($y = 0; $y < $height; ++$y) {
$color = ColorUtil::getColorAt($aResource, Coordinate::create($x, $y));
if (!isset($colorMap[$color->getColorIndex()])) {
// calculate the new color
$hsl = ColorUtil::rgb2hsl($color->getRed(), $color->getGreen(), $color->getBlue());
$hsl[0] += $this->degrees;
$rgb = ColorUtil::hsl2rgb($hsl[0], $hsl[1], $hsl[2]);
$newcol = imagecolorallocate($aResource->getResource(), $rgb[0], $rgb[1], $rgb[2]);
$colorMap[$color->getColorIndex()] = $newcol;
} else {
$newcol = $colorMap[$color->getColorIndex()];
}
imagesetpixel($aResource->getResource(), $x, $y, $newcol);
}
}
$colorMap = null;
}
public function testRgb2hsl()
{
$this->assertEquals(array(0, 0, 100), ColorUtil::rgb2hsl(255, 255, 255), "Error converting rgb white into hsl");
$this->assertEquals(array(0, 0, 0), ColorUtil::rgb2hsl(0, 0, 0), "Error converting rgb black into hsl");
$this->assertEquals(array(120, 100, 50), ColorUtil::rgb2hsl(0, 255, 0), "Error converting rgb green into hsl");
$this->assertEquals(array(240, 100, 50), ColorUtil::rgb2hsl(0, 0, 255), "Error converting rgb blue into hsl");
}
