The idea is to check all recipes if they make an item that contains wood, if the list of ingredients is completely broken down. It's relatively easy to check the list of ingredients of one recipe, but consider this example from Bio Industries:
- The vanilla wooden chest is made from wood. Wood is the only ingredient, so that's easy to catch.
- Our medium wooden chest requires no wood, but several vanilla wooden chests and additional ingredients.
- Our large wooden chest requires no wood and no vanilla wooden chests, but several medium wooden chest + other ingredients.
- We also have a giant wooden chest that, again, takes no wood but several large wooden chests + other ingredients.
I'm not sure if my idea really makes sense because one item can be the result of several recipes, and it may well be possible that one recipe would require wood while another doesn't. Also, recipes may have difficulty, and it may be possible that recipe.normal.ingredients contains wood while recipe.expensive.ingredients doesn't, or that different amounts of wood are used in the different difficulties. I therefore allowed for the following simplification:
- If at least one recipe producing the item requires wood, this item will get a fuel value.
- Use the amount of wood used in recipe.normal.ingredients, or recipe.expensive.ingredients, or recipe.ingredients (in this order).
- If several recipes containing wood as ingredient produce an item, use the one with the highest amount of wood as reference for calculating the fuel value.