World Generator Help

I have a custom generator that I am planning to use for my Plots server and I have a function that I need to edit to make the generated terrain look like this: http://imgur.com/a/uKiZW
Using the given info in the function, how can I generate the world to look like I want?

PHP:

public function generateChunk($chunkX, $chunkZ) {
        $shape = $this->getShape($chunkX << 4, $chunkZ << 4);
        $chunk = $this->level->getChunk($chunkX, $chunkZ);
        $chunk->setGenerated();
        $c = Biome::getBiome(1)->getColor();
        $R = $c >> 16;
        $G = ($c >> 8) & 0xff;
        $B = $c & 0xff;
        $bottomBlockId = $this->bottomBlock->getId();
        $bottomBlockMeta = $this->bottomBlock->getDamage();
        $plotFillBlockId = $this->plotFillBlock->getId();
        $plotFillBlockMeta = $this->plotFillBlock->getDamage();
        $plotFloorBlockId = $this->plotFloorBlock->getId();
        $plotFloorBlockMeta = $this->plotFloorBlock->getDamage();
        $roadBlockId = $this->roadBlock->getId();
        $roadBlockMeta = $this->roadBlock->getDamage();
        $debugBlockId = $this->debugBlock->getId();
        $debugBlockMeta = $this->debugBlock->getDamage();
        $groundHeight = $this->groundHeight;
        for ($Z = 0; $Z < 16; ++$Z) {
            for ($X = 0; $X < 16; ++$X) {
                $chunk->setBiomeId($X, $Z, 1);
                $chunk->setBiomeColor($X, $Z, $R, $G, $B);
                $chunk->setBlock($X, 0, $Z, $bottomBlockId, $bottomBlockMeta);
                for ($Y = 1; $Y < $groundHeight-3; ++$Y) {
                    $chunk->setBlock($X, $Y, $Z, Block::AIR, $plotFillBlockMeta);
                }
                for ($Y = $groundHeight-3; $Y < $groundHeight; ++$Y) {
                    $chunk->setBlock($X, $Y, $Z, $plotFillBlockId, $plotFillBlockMeta);
                }
                $type = $shape[($Z << 4) | $X];
                if ($type === self::PLOT) {

                    $chunk->setBlock($X, $groundHeight, $Z, $plotFloorBlockId, $plotFloorBlockMeta);
                } elseif ($type === self::ROAD) {
                    $chunk->setBlock($X, $groundHeight, $Z, $roadBlockId, $roadBlockMeta);
                } else {
                    //$chunk->setBlock($X, $groundHeight, $Z, $debugBlockId, $debugBlockMeta);
                    $chunk->setBlock($X, $groundHeight + 1, $Z, $debugBlockId, $debugBlockMeta);
                }
            }
        }
        $chunk->setX($chunkX);
        $chunk->setZ($chunkZ);
        $this->level->setChunk($chunkX, $chunkZ, $chunk);
    }


https://forums.pmmp.gq/threads/world-generator-help.67/

To be honest, I don't really develop in PHP anymore, just HTML. I would recommend that you ask at the new PocketMine forums. There more active then these old ones, and people other than Shogi have admin access to them.

Also, as a message to everyone, include a link to the new ones in your signature for SEO and information purposes