A chess game for the NEAR network. The pieces move properly, but I still need to implement some kind of authentication for the players. Also need to properly implement testing/better documentation. But it's still useful as a study material though.
For testing the project, I usually create a subaccount, deploy to it, run my functions and then delete the subaccount.
Call "near login" to enter your main account. Let's say I have a testnet account called "a-test-account.testnet". In that case, I call "near create-account rust-tests.a-test-account.testnet --masterAccount a-test-account.testnet --initialBalance 100" to create a subaccount with name rust-tests and a deposit of 100 NEAR. When I'm done using the deployed project, I would call "near delete rust-tests.a-test-account.testnet a-test-account.testnet", which means the subaccount gets deleted and all the remaining NEAR is transferred back to a-tests-account.testnet.
Bring a terminal to this folder.
cargo +nightly build --target wasm32-unknown-unknown --release
Might need to add wasm32-unknown-unknown before doing the above. A message will show up saying it.
cd ./target/wasm32-unknown-unknown/release
To reach the folder with the compiled wasm.
near deploy --accountId rust-tests.a-test-account.testnet --wasmFile ./chess.wasm
If everything goes well, the subaccount now contains the compiled project. We can run it's functions remotely.
Check lib.rs to see available functions. Functions with &self can be called with view. Functions with &mut self can be called with call.
near view rust-tests.a-tests-account.testnet get_board '{}'
Will print a very ugly version of the board. It's stored as 64 bytes, so we can't expect much from it. Numbers go from 0 to 12, here's what they mean:
- 0: Empty piece;
- 1: White Pawn;
- 2: White Rook;
- 3: White Knight;
- 4: White Bishop;
- 5: White Queen;
- 6: White King;
- 7: Black Pawn;
- 8: Black Rook;
- 9: Black Knight;
- 10: Black Bishop;
- 11: Black Queen;
- 12: Black King
near view rust-tests.a-tests-account.testnet get_piece_name '{"col": 7, "row": 7}'
Will get the piece in the bottom right corner of the board. A "White Rook". Columns and rows go from 0 to 7, get_piece_name_index does the same thing but you use the index of the entire board instead. For the same position the index would be 63.
near call rust-tests.a-tests-account.testnet move_to '{"current_col": 0, "current_row": 6, "target_col": 0, "target_row": 4}' --account-id a-tests-account.testnet
Will make the bottom white pawn move forward two steps (If it's the white player's turn).
There's also a function to reset the game and get the game status. Please check them out.
I ran the methods from the tests sections in the main lib file. Checking in the explorer, the gas used to deploy the contract was 25TGas. To run each move function the gas cost was 6TGas. To run the last move function that caused the checkmate, the gas cost was 7TGas.
Multiply it by the cost in https://explorer.near.org/ to get the cost in Near for each move function.
At the time of writing this section of the README (jan 6 2022). The cost for each TGas is 0.0001 Ⓝ. The cost for each Ⓝ is U$16.02 . So each function call will cost 0.009612 dollars (TGas used * TGas cost * NearCost(dollars)).
A chess match takes from 40 to 60 moves to end. So a player should play around 2 matches for each dollar spent. In other words, mining near must be very worthwhile right now. I'm not an expert in mining, don't rely too much on my word please.