/**
* Return the average of the RGB value of two Image_Color2 objects. If
* both objects have an alpha channel it will be averaged too.
* <code>
* $red = new Image_Color2('red');
* $blue = new Image_Color2('blue');
* $color = Image_Color2::average($red, $blue);
* print $color->convertTo('named')->getString(); \/\/ 'purple'
* </code>
*
* @param Image_Color2 $left Left color
* @param Image_Color2 $right Right color
*
* @return Image_Color2
*/
public static function average(Image_Color2 $left, Image_Color2 $right)
{
$lrgb = $left->getRgb();
$rrgb = $right->getRgb();
// remove the type element so we can properly compare lengths
unset($lrgb['type']);
unset($rrgb['type']);
// the color may be RGB or RGBA, either way, they need to be the same
// length.
$size = min(count($lrgb), count($rrgb));
// find the average of each pair of elements
$avg = array();
for ($i = 0; $i < $size; $i++) {
$avg[] = (int) (($lrgb[$i] + $rrgb[$i]) / 2 + 0.5);
}
return new Image_Color2($avg);
}
function testAverage_Rgba()
{
$red = new Image_Color2(array(255, 0, 0, 255));
$blue = new Image_Color2(array(0, 0, 255, 0));
$result = Image_Color2::average($red, $blue);
$this->assertSame('Image_Color2', get_class($result));
$this->assertEquals(array(128, 0, 128, 128, 'type' => 'rgb'), $result->getArray());
}