Help: Adding and implementing new commerce types?

[MrUnderhill]

Hi, I'm trying to add a new commerce type (like Research and Culture) but I can't find any tutorials on how to do it. My plan was to have priests and religious buildings provide a "Piety" commerce type that would affect how quickly your state religion spreads, among other things. Has anyone done this before who could give me advice on where to get started?

 

[EmperorFool]

Commerce and Yield Types are hard-coded in the SDK (DLL), so you'll need to do some C++ work to add a new one. Start by adding your new type to CvEnums.h:

enum CommerceTypes					// Exposed to Python
{
	NO_COMMERCE = -1,

	COMMERCE_GOLD,
	COMMERCE_RESEARCH,
	COMMERCE_CULTURE,
	COMMERCE_ESPIONAGE,
	[B]COMMERCE_PIETY,[/B]

#ifdef _USRDLL
	NUM_COMMERCE_TYPES
#endif
};

You'll want to expose the new value to Python in CyEnumInterface.cpp as well. There will most likely be other C++ changes you'll need to make to handle it.

Finally, I believe you'll also need to modify all the XML files (e.g. buildings and techs) which specify commerce values.

 

[MrUnderhill]

Okay, so far so good. I added the enums to the SDK, tweaked a few XML files so that priests give Piety as a commerce type, then compiled and ran with no problems. It even shows up in the 'pedia as a plain number, but for the life of me I can't tell where icons are loaded for each commerce type. There's a setChar function under CvCommerce infos but it doesn't look like it's being used anywhere. How do you set a commerce type to an icon?

 

[EmperorFool]

All the commerce/yield icons are in the two font files (Res/Fonts). I would guess that you need to place your new icon in the cell to the right of the icon. DXTBmp is a program that will let you modify the files. Make sure you place the little green dot using exactly the same color as the others to mark the cell as active.