Tile Categories

This dialog allows you to categorize tiles for the purposes of defining "Solidity Definitions" and for use with player map interactions. The right half of the dialog is dedicated to defining Solidity Definitions.

Each tile category applies to a specific tileset. While the categories are saved with the project (in the GDP file), they are effectively indexed by tileset. This means you can have a category named "Solid" for Tileset1 and another category named "Solid" for Tileset2. A category simply consists of a number of tile indexes. Internally the category is a sequence of 256 bits (32 bytes) which can be used to very quickly determine whether a tile is a member of the category. Each bit represents "Yes" or "No" for whether one of the possible 256 tiles in the tileset is a member of the category.

The process of defining a category generally consists of these steps:

• Select a tileset from the "Tileset" box
• Enter a name for the category you wish to create (or select the name of a category you wish to edit) from "Current Category"
• Drag tiles from the lower box ("Tiles available in tileset") to the upper box ("Tiles in this category") to add tiles to the category.
• If you want to remove tiles from the category, drag them from the upper box to the lower box.

By dragging a tile into the upper box, the category named in "Current Category" is automatically created if it doesn't already exist. Changes to a category take effect immediately and do not need to be explicitly updated. Deleting a category simply involves selecting it from the "Current Category" list and clicking the "Delete Category" button. Only one category will be deleted. Categories with the same name for different tilesets will not be affected.

You can use the Ctrl and Shift keys while selecting tiles to select multiple tiles or ranges of tiles.

Solidity Definitions

A Solidity Definition can be used in the "Sprites and Paths" dialog to define how particular types of sprites see the map (which tiles they see as solid etc).

To create a "Solidity Definition" you must have at least one group of tiles that represent blocks that are solid (or partially solid). Since Solidity Definitions are also specific to a tileset, you must first select a tileset from the tileset list at the top left of the dialog. Type the name of the Solidity Definition you want to create into the "Solidity Definition Name" field. This name, like a category name, is specific to a tileset. Alternatively, select an existing solidity definition if you want to edit one. Then, in the "Solid tile category" list, select the category of tiles that represents solid blocks in the current tileset (or "<none>" of you don't have any completely solid tiles). Tiles in this category are interpreted as completely solid. If you have tiles that represent the following shapes, select that category in the corresponding box indicated below (black area = non-solid):

	Uphill tile category
	Downhill tile category
	Ceiling up tile category
	Ceiling down tile category

All uncategorized tiles are assumed to be empty (non-solid).

If your tiles are not square, these are the rules used for determining which part of the tile is solid:

• The slope of all separations between solid and non-solid are 0, infinity, -1 or 1 (all diagonal lines are at nice 45 degree angles)
• The uphill slope of an uphill tile always starts at the bottom left; anything above that is empty and anything to the right of that is solid.
• The downhill slope of a downhill tile always starts at the top left; anything below that is solid and anything to the right of that is empty.
• The uphill slope of an upward ceiling tile always starts at the bottom left; anything above that is solid and anything to the right of that is empty.
• The downhill slope of a downward ceiling tile always starts at the top left; anything below that is empty and anything to the right of that is solid.

To delete a Solidity Definition, select the tileset you wish to delete it from at the top left, select the name from "Solidity Definition Name" and then click "Delete". This does not delete the categories involved in the solidity definition, just the grouping of these categories as a Solidity Definition (just as deleting a category does not delete the tiles themselves).

All tile categories and solidity definitions are saved in the GDP project file.