NamedTileOrderedIndexes

Introduction

The NameTileOrderedIndexes property can be used to find tiles by a given name. It is a Dictionary<string, List<int>> , where the key is a name, and the value is the index of tiles which have the given name.

Tile Ordered Indexes

The MapDrawableBatch object stores a list of vertices (points) which are used to define the coordinates for each tile. These points are used by the rendering code in the MapDrawableBatch class to perform efficient rendering. Each tile is composed of a list of vertices, as opposed to a Sprite (as might be the case if the MapDrawableBatch were a FlatRedBall-drawn object). Therefore, to access and modify properties on a tile, its index must be known. The following image shows the indexes of a simple tile map:

Code Example

The following code example shows how to create an Entity for every tile with the name "CreateEntity".

// The following assumes that LayeredTileMapInstance is a valid LayeredTileMap:
foreach(var layer in LayeredTileMapInstance.Layers)
{
    // See if this layer has any tiles with the name "CreateEntity"
    if(layer.NamedTileOrderedIndexes.ContainsKey("CreateEntity"))
    {
        List<int> indexes = layer.NamedTileOrderedIndexes["CreateEntity"];

        // Loop through all of the tile indexes
        foreach(int index in indexes)
        {
            float left;
            float bottom;
            layer.GetBottomLeftWorldCoordinateForOrderedTile(index, out left, out bottom);

            // This gives us the left and bottom of the tile, but we want to add half the width
            // and height to get the center of the tile.  For this we'll assume the width and height
            // of the tiles is 16 pixels, but you will want to adjust this to account for your actual width/height
            const float tileWidthAndHeight = 16;            
            float centerX = left + tileWidthAndHeight/2.0f;
            float centerY = bottom + tileWidthAndHeight/2.0f;

            // Assume that we have an Entity called Coin:
            Coin coin = new Coin();
            coin.X = centerX;
            coin.Y = centerY;
            // And assume that CoinList is a valid list of Coins
            CoinList.Add(coin);
        }
    }
}

Setting the Name in Tiled

Tiles will only have properties at runtime if it uses a tile in a tileset with a Name property.