040 : Node 040

Two player game, so we need to use some keys for player 1 and some other keys for player 2.

Move check_input() into update_world() since we need to use it for both players.

script.js: Move check_input()

// Handle input and move player 1. // Handle movement for Player 1. function update_player1() { check_input(); _player1.x += _player1.velocity_x; _player1.y += _player1.velocity_y; } function check_input() { ... } // This is called ~60 times per second to update the world. function update_world() { check_input(); update_player1(); draw(); requestAnimationFrame(update_world); }

Run your code in a browser and verify that there are no errors.

Update check_input() to handle keys for both players.

Use WASD for player 1 and arrow keys for player 2.

Players can only move up and down, so we never need to update velocity_x.

Since players can only move up and down, we also remap left/right to up/down.

script.js: Update key handling

function check_input() { _player1.velocity_x = 0; _player1.velocity_y = 0; // Left arrow or 'a' to move left. if (_game.keymap[37] || _game.keymap[65]) { _player1.velocity_x = -1; } // Right arrow or 'd' to move right. if (_game.keymap[39] || _game.keymap[68]) { _player1.velocity_x = 1; } // Up arrow or 'w' to move up. // Player 1 uses the WASD keys to move. // 'w' or 'a' to move up. if (_game.keymap[38] || _game.keymap[87]) { if (_game.keymap[87] || _game.keymap[65]) { _player1.velocity_y = -1; } // Down arrow or 's' to move up. // 's' or 'd' to move up. if (_game.keymap[40] || _game.keymap[83]) { if (_game.keymap[83] || _game.keymap[68]) { _player1.velocity_y = 1; } _player2.velocity_y = 0; // Player 2 uses the Arrow keys to move. // Up arrow or Right arrow to move up. if (_game.keymap[38] || _game.keymap[39]) { _player2.velocity_y = -1; } // Down arrow or Left arrow to move up. if (_game.keymap[40] || _game.keymap[37]) { _player2.velocity_y = 1; } }

Run your code in a browser and verify that there are no errors.

Player 2 doesn't move yet.

GOTO 050