Edit Tilesets Dialog

Since the full screen Tileset Editor (accessed through the Create and Edit buttons on this dialog) is very involved, help for this topic has been split into two files:

• This file describes the use of the dialog itself
• The Full Screen Tileset Editor describes the use of the editor.

At the top left of this dialog is a list of "Tilesets" defined in the project. A Tileset is an appropriately sized bitmap associated with a tile width and a tile height used to split up the bitmap into tiles. The graphics for a tileset are stored in a BMP Windows bitmap file while the overall definition (the reference to the file, and parameters indicating how the graphics are split into tiles) is stored in the GDP project file. Indicated in this list of tileset definitions is a "[U]" or "[L]" at the begining of each entry indicating if the tileset graphics are currently loaded into memory ("[L]") or unloaded ("[U]"). Often times GameDev will attempt to only load those graphics that are being used and unload a tileset graphic when its done being used. Of course a modified tileset must remain in memory until it is saved (or discarded).

Selecting a tileset in this list will load the parameters of the tileset into the fields below. The "Tile Columns" and "Tile Rows" values will not be filled in unless the tileset image is loaded. This is because the rows and columns are calculated based on the image size (divided by the tile size), and the image size is unknown unless the image is loaded. You may then modify them and update the tileset. Creating a tileset generally follows these steps:

• Specify a width and height (in pixels) for the tiles in the tileset in the "Tile Width" and "Tile Height" fields. Maximum dimensions (limited by tileset editor) is 128x128 pixels Woohoo! (Before verison 1.4, the maximum was 64x64.) Many dialogs have changed size to accommodate display of the larger tiles. Furthermore, if you edit tiles that are greater than 64 pixels high or wide, the tileset editor will open in 800x600 mode. That means your video card has to support 800x600 mode with the color depth you have specified for the editor.
• Specify the number of rows and columns of tiles in the tileset. The total number of tiles (rows * columns) must be 256 or less. The number of columns should not cause the width of the tileset to exceed 640 pixels (columns * width <= 640). An ideal size if you want to use the maximum number of tiles is 16x16 tiles, assuming that fits within the 640 pixel width. Technical Note: According to updated DirectX documentation, DirectX 5.0 and later allows you to create surfaces wider than the current display resolution, but if the video hardware does not support this, the surface will be created in system memory instead of display memory resulting in slower graphics operations. GameDev, having been designed with the limitation in mind, was never designed to display tilesets wider than the display in the Map Editor so you will be unable to use a tileset wider than the display in GameDev. With the introduction of higher screen resolutions in 1.4, some of these problems may no longer be an issue, but I'm not prepared to test this. Considering there's no practical limit to the height of the tileset, this shouldn't limit you in the kind of tiles you can create since the maximum width of a tile is already well below the maximum width of a tileset. You could easily make a 1-column tileset.
• Type a name for the new tileset.
• Select a video mode compatible with your video card for the"Screen Depth" setting (if you select an incompatible mode you will just get an error and be returned to the edit tilesets dialog). Be careful not to select 16-bit color if you're going to edit an existing 24-bit color tileset. The tileset takes on the color depth of the display, and once you lose the extra color information you can't get it back unless you still have a saved copy.
• Click the "Create" button to create the bitmap and open it up in the full screen editor.

The Edit button will load the selected tileset into the editor to update the graphics. Save Image will save the graphics to a specified BMP file. The path that the image for the currently selected tileset is currently saved to is displayed in the "Path" box at the bottom right. Save All saves all loaded tileset graphics, prompting for filenames if necessary. Load Image can be used to load an existing bitmap as a new tileset. Before clicking the Load Image button you must specify a name for the new tileset and specify the tile width and tile height. The columns and rows will be calculated based on the image size. If the width of the image is not a multiple of the tile width or the height of the image not a multiple of the tile height, some pixels will be cropped off, the tileset will exclude the partial tiles.

The Remove button removes the tileset definition from the project. It does not do anything to the BMP file itself. The Import Tile button can be used to import a single tile from another image. Unlike the "Load Image" button, this lets you pick a single tile-sized piece out of an existing picture instead of loading the whole image into the project. After selecting the portion you want to import, the tile is loaded into the editor. The tileset itself is not affected until you store the tile into a slot in the tileset.

The update button can be used to change the parameters of a tileset after it is created or loaded from an existing image. If you change the tile size, partial tiles may be clipped off. Be sure to select an appropriate screen depth before activating this command because it uses the full screen tileset editor momentarily to update the image (for instance, if the number of tiles changed). Note that updates to the parameters are made in this order:

• The size of the bitmap is updated to the new number of columns and rows (based on the old tile size)
• The size of the tiles is updated
• The number of columns and rows is recalculated based on the new tile size (when you click on the tileset)