Mirage Source

Tutorial - Multi item shop trades - MSE Build 1 - Tested and working

Server side changes
-----------------------

First of all open up modConstants and add this code along with the other MAX values.



The server doesn't seem to like a MAX_SHOPS value above 70ish when it writes a new shops.ini file (with the above
MAX values), I would recommend you set it to this or below.

Next, open modTypes and modify the TradeItemRec to look like this.



We'll move onto modDatabase now to sort out the loading and saving of the new trade values.
You'll need to modify both the SaveShop and LoadShop subs to allow for all the extra item information.





Now we've defined the new shop trade combinations we have to deal with sending this information to the client
and receiving the modified data back from the client.

First of all, in modHandledata, modify the Save Shop Packet to include the extra item data.
A new variable 'f' needs to be declared so add the following at the top of Sub HandleData.





The Trade Request Packet is sent to the server every time a character tries to buy something from a shop.
Change the code, as shown below, to check if the player has all the items that might make up the trade,
and give them all the items they have bought.



Then, in the modServerTCP, adjust the makeup of the packets in the SendEditShopTo and SendTrade subs to allow
for multiple items.






Just one last sub to change now, open up modGameLogic and modify the ClearShop sub to zero all the item
values when the server starts up.



That's all for the server side......


First job client side is to add the new shop trade definitions, in modTypes change the
TradeItemRec to look like the code below.



As with the server, we need to add the maximum amount of items a player gives for a trade
and the maximum amount of items they receive, in modConstants add the following code in with
the other MAX Constants.



Now would be a good time for us to tackle the changes to frmShopEditor, bring up the form and move the controls
apart a little to create a gap between the 'fixes items' checkbox and the 'item give' combobox, then again between the 'value' textbox for 'item give' and the 'item get' combobox.
Right, follow this next part closely, there are new controls to add and the old give/get item controls will be re-named.

In the first gap;
* add a label with the caption 'Give Item',
* add a scrollbar next to that called 'scrlGiveItem' with the 'Min' value set to 1,
* add a label to the end of the scrollbar named 'lblGiveItem' with 'Autosize' set to TRUE and the 'Caption' as '1'.
* now change the 'cmbItemGive' comboboxes name to 'cmbShopItemGive'
* and change the 'txtItemGiveValue' textboxes name to 'txtShopGiveValue'.

In the second gap;
* add a label with the caption 'Get Item',
* add a scrollbar next to that called 'scrlGetItem' with the 'Min' value set to 1,
* add a label to the end of the scrollbar named 'lblGetItem' with 'Autosize' set to TRUE and the 'Caption' as '1'.
* now change the 'cmbItemGet' comboboxes name to 'cmbShopItemGet'
* and change the 'txtItemGetValue' textboxes name to 'txtShopGetValue'.

With that done we can change the associated code, bring up the forms code window, locate Sub cmdShopUpdate_Click()
and comment out all the code except for the call to 'UpdateShopTrade'.
Now add the following code to the end to deal with the controls we've added and the ones we modfied.















There aren't any real visual changes to frmTrade to be made, although you may want to widen 'lstTrade' to cope with the longer trade descriptions.
No changes to the code for this form either, so we'll move onto the changes in packet data.

First up is the Edit Shop Packet in modHandledata, more changes in view of the extra items per trade.
I've used another variable for each item in the GIVE and GET ITEM arrays and a new string variable for each trade description, so add this code to the top of Sub HandleData with the other Dim statements,



Modify the Edit shop Packet to look like the code below.



The Trade Packet will also need to be changed to the code below for when the client receives the shop trades data.



Over to frmClientTCP now, find the sub SendSaveShop and change it to the following code.



Lastly we come to modGameLogic, the changes here set how the shop editor displays the new trade item information.
Once again, modify the code to look like the code that follows.







And There you have it, you should now be able to set up multiple item trades in your shops.
It's best to delete the shops.ini file in the Data folder server side before running the server again.
It is possible to change the MAX_GIVE_ITEMS and MAX_GET_ITEMS and _VALUE constants to give different combinations.
NB: with MAX_GIVE_ITEMS set to 5 and MAX_GET_ITEMS set to 2, an .ini file will hold just over 70 shops.

** Know Issue - There is one last sub or code modification that this tutorial needs to complete it, I haven't gotten around to adding it to my source yet so you'll have to make it up yourself.
Basically it concerns the servers check for open inventory slots, at the moment if a player has just one open inventory slot the FindOpenInvSlot sub will find that open slot for each Get Item the character will receive, meaning the player will run out of inventory before they get all the items their due.
Best of Luck.

Does this Only work for MSE Build 1 or will it also work for MS V3.0.3?

Should work for both.