must be of the type string, resource given,

$capeData = @imagecreatefrompng( $this->plugin->getDataFolder() . "cape.png" );

 

please give all the code, and show which line does the error come from

 

/** @var Player $player */
/** @var string $capeData */
$skin = $player->getSkin();
$player->setSkin(new Skin($skin->getSkinId(), $skin->getSkinData(), $capeData, $skin->getGeometryName(), $skin->getGeometryData()));

 

capeData must be a string just like SkinData

 

It must be string, not resource.

Firstly convert .png to string with this function. You can use this on every gd operation.

PHP:

public function convertToString(string $file) : string{
        assert(file_exists($file));
        $image = imagecreatefrompng($file);
        $data = '';
        for($y = 0, $height = imagesy($image); $y < $height; $y++){
            for($x = 0, $width = imagesx($image); $x < $width; $x++){
                $color = imagecolorat($image, $x, $y);
                $data .= pack("c", ($color >> 16) & 0xFF)
                    . pack("c", ($color >> 8) & 0xFF)
                    . pack("c", $color & 0xFF)
                    . pack("c", 255 - (($color & 0x7F000000) >> 23));
            }
        }
        imagedestroy($image);
        return $data;
}

After set player skin.

PHP:

$capeData = $this->convertToString($this->plugin->getDataFolder() . "cape.png");
$skin = $player->getSkin();
$player->setSkin(new Skin($skin->getSkinId(), $skin->getSkinData(), $capeData, $skin->getGeometryName(), $skin->getGeometryData()));
$player->sendSkin();

 

thanks cap