Your Opinions Please

[lazzybiznatch]

Hi, I am coding a map engine and my first approach was to use arrays to hold the tiles information, preferable 2 dimension arrays. Unfortunately there are several layers to the map. Like layer 1 would be ground tiles, then 2 would be like shadows, and so on. I have up to 15 layers with individual tile information. Btw, each layer would get its own database row (mysql).

Second approach was to make the whole thing one big 3 dimension array. When I did that, it turned out that the amount of text for the array wouldn’t even fit in the text field in the mysql database 🙁

Third approach was to build the map with xml and use the markup language to define each attribute to each tile...

<tile>
<id>1</id>
<tile>grass.gif</tile>
<shadow>tree1shadow.gif</shadow>
</tile>

Something like that. However I ran into the same problem as the 3D array...WAY to big. And not only that, it took php to the point of a 'ive been running to long' error to parse the whole thing.

SO, if any of you out there have any suggestions to how I should go about storing or creating this project it would be greatly appreciated 🙂

Some Other info that might be helpful:
- MySQL
- PHP 5
- Map size is 32x32 tiles and max width/height is still undetermined (limited by how big the array will be or whatever I use)
- Users will only see a portion of the map at a time, again, that’s undetermined
- AJAX for movement and combat and whatnot

[NogDog]

Well, databases are made for holding data and processing it efficiently, so that would seem to me to be the way to go. Possibly two tables:

grid
==========
grid_id  INT AUTOINCREMENT PRIMARY KEY
grid_x   INT
grid_y   INT
(any other info needed to define a grid location)

layer
============
grid_id   INT
layer_number  TINYINT   [this would be the "level" of the layer]
layer_image  VARCHAR   [name of the image file]
[the combination of grid_id and layer_number would be defined as UNIQUE]

[lazzybiznatch]

Interesting approch. I have it set up as just one table right now with all the info like: mapname, created, bla, bla, bla, layer1, layer2, layer3, layer4 and so on

I think yours would be good if the maps shared layers between them, but seeing as every map will be unique, wouldnt it be better to just have all the data in one table? Maybe im just seeing your idea differently?

[NogDog]

I guess I just like the idea of separating the map grid location and the image layers associated with them into different data objects. As far as performance, I don't know if either way would necessarily be better. It might not make any difference now, but it might be a bit more flexible if the project expands and you find yourself adding more layers, wanting to store other info associated with map grids, and all those things you haven't though of yet that will crop up as you get further into the project. 🙂

[jdorsch]

You should do it in a database and normalize it as was stated. Secondly, anything that is reused should be stuck into another table and referred to with keys -> if your images are reused make an images table. This will help with not only the amount of data in memory being less since you will only need to store integers instead of full file names, but if the name of an image changes, you only have to change it in one spot.

Another thing is instead of arrays start thinking in objects

$grassImage = new TileImage() ;
$grassImage->setImageName('grass.gif') ;

$shadowImage = new TileImage() ;
$shadowImage->setImageName('tree1shadow.gif') ;

$tile = new Tile() ;
$tile->setTileImage( $grassImage ) ;
$tile->setShadow( $shadowImage ) ;

// X Y position of tile on map
$x= 10 ;
$y = 32 ;

$map = new Map( 32, 32 ) ;
$map->addTile( $x, $y, $tile ) ;

// Save the map to the database
$map->save() ;

// get an image name for some tile
$imageName = $map->getTile( $x, $y )->getTileImage()->getImageName() ;


// If you implement IteratorAggregate within your Map class you can do this

foreach( $map as $rowNum => $mapRow )
{
   echo $rowNum ;
   foreach( $mapRow as $tile )
   {
      echo $tile->getShadow()->getImageName() ;
   }
}