带有移动按钮控件的贪吃蛇游戏

Question

In this Snake game, I need the buttons to control the snake just like the arrow keys do. This will allow the game to be played on a mobile device. You can see i have code in there for the buttons, but they are not working properly and not controlling the movement of the snake.

Any advice to make the buttons work would be greatly appreciated! thanks!

HTML

<section class="game" id="share">

<div class="container">

    <div class="columns twelve borders center">

        <div class="game-container">

            <div class="container">

                <div class="SplashScreen">
                    <h1>
                        Snake
                    </h1>
                    <h2>
                        Click To Start.
                    </h2>
                    <input class="StartButton" type="button" value="Start" />
                </div>

                <div class="FinishScreen" style="display:none">
                    <h1>
                        Game Over
                    </h1>
                    <p>
                        Your score was: <span id="score"></span>
                    </p>
                    <input class="StartButton" type="button" value="Restart" />
                </div>

                <canvas id="canvasArea" height="300" width="300" style="display:none;"></canvas>

            </div>

            <div class="button-pad">
                <div class="btn-up">
                    <input type="image" src="http://aaronblomberg.com/sites/ez/images/btn-up.png" alt="Up" class="button up-btn" />
                </div>

                <div class="btn-right">
                    <input type="image" src="http://aaronblomberg.com/sites/ez/images/btn-right.png" alt="Right" class="button right-btn" />
                </div>

                <div class="btn-down">
                    <input type="image" src="http://aaronblomberg.com/sites/ez/images/btn-down.png" alt="Down" class="button down-btn" />
                </div>

                <div class="btn-left">
                    <input type="image" src="http://aaronblomberg.com/sites/ez/images/btn-left.png" alt="Left" class="button left-btn" />
                </div>
            </div>

        </div>

    </div>

</div>

</section>

JAVASCRIPT

( function( $ ) {

    $( function() {

        $(document).ready(function () {

            $(".StartButton").click(function () {
                $(".SplashScreen").hide();
                $(".FinishScreen").hide();
                $("#canvasArea").show();
                init();
            });

            //Canvas stuff
            var canvas = $("#canvasArea")[0];
            var ctx = canvas.getContext("2d");
            var w = $("#canvasArea").width();
            var h = $("#canvasArea").height();

            //Lets save the cell width in a variable for easy control
            var sw = 10;
            var direction;
            var nd;
            var food;
            var score;

            //Lets create the snake now
            var snake_array; //an array of cells to make up the snake

            function endGame() {
                $("#canvasArea").hide();
                $("#score").text(score);
                $(".FinishScreen").show();
            }

            function init() {
                direction = "right"; //default direction
                nd = [];
                create_snake();
                create_food(); //Now we can see the food particle
                //finally lets display the score
                score = 0;

                //Lets move the snake now using a timer which will trigger the paint function
                //every 60ms
                if (typeof game_loop != "undefined") clearInterval(game_loop);
                game_loop = setInterval(paint, 60);
            }

            function create_snake() {
                var length = 5; //Length of the snake
                snake_array = []; //Empty array to start with
                for (var i = length - 1; i >= 0; i--) {
                    //This will create a horizontal snake starting from the top left
                    snake_array.push({
                        x: i,
                        y: 0
                    });
                }
            }

            //Lets create the food now
            function create_food() {
                food = {
                    x: Math.round(Math.random() * (w - sw) / sw),
                    y: Math.round(Math.random() * (h - sw) / sw),


                };
                //This will create a cell with x/y between 0-44
                //Because there are 45(450/10) positions accross the rows and columns

            }

            //Lets paint the snake now
            function paint() {
                if (nd.length) {
                    direction = nd.shift();
                }

                //To avoid the snake trail we need to paint the BG on every frame
                //Lets paint the canvas now
                ctx.fillStyle = "#0056a0";
                ctx.fillRect(0, 0, w, h);
                ctx.strokeStyle = "#ffffff";
                ctx.strokeRect(0, 0, w, h);

                //The movement code for the snake to come here.
                //The logic is simple
                //Pop out the tail cell and place it infront of the head cell
                var nx = snake_array[0].x;
                var ny = snake_array[0].y;

                //These were the position of the head cell.
                //We will increment it to get the new head position
                //Lets add proper direction based movement now
                if (direction == "right") nx++;
                else if (direction == "left") nx--;
                else if (direction == "up") ny--;
                else if (direction == "down") ny++;

                //Lets add the game over clauses now
                //This will restart the game if the snake hits the wall
                //Lets add the code for body collision
                //Now if the head of the snake bumps into its body, the game will restart
                if (nx == -1 || nx == w / sw || ny == -1 || ny == h / sw || check_collision(nx, ny, snake_array)) {
                    //end game
                    return endGame();
                }

                //Lets write the code to make the snake eat the food
                //The logic is simple
                //If the new head position matches with that of the food,
                //Create a new head instead of moving the tail
                if (nx == food.x && ny == food.y) {
                    var tail = {
                        x: nx,
                        y: ny
                    };
                    score++;

                    //Create new food
                    create_food();
                } else

                {
                    var tail = snake_array.pop(); //pops out the last cell
                    tail.x = nx;
                    tail.y = ny;
                }

                //The snake can now eat the food.
                snake_array.unshift(tail); //puts back the tail as the first cell

                for (var i = 0; i < snake_array.length; i++) {
                    var c = snake_array[i];

                    //Lets paint 10px wide cells
                    paint_cell(c.x, c.y);
                }

                //Lets paint the food
                paint_cell(food.x, food.y);

                //Lets paint the score
                var score_text = "Score: " + score;
                ctx.fillStyle = "#ffffff";
                ctx.fillText(score_text, 5, h - 5);

                //Set the font and font size
                ctx.font = '12px Arial';

                //position of the fill text counter
                ctx.fillText(itemCounter, 10, 10);

            }

            //Lets first create a generic function to paint cells
            function paint_cell(x, y) {
                ctx.fillStyle = "#d8d8d8";
                ctx.fillRect(x * sw, y * sw, sw, sw);
            }

            function check_collision(x, y, array) {
                //This function will check if the provided x/y coordinates exist
                //in an array of cells or not
                for (var i = 0; i < array.length; i++) {
                    if (array[i].x == x && array[i].y == y) return true;
                }

                return false;
            }

            // Lets prevent the default browser action with arrow key usage
            var keys = {};
            window.addEventListener("keydown",
                function(e){
                    keys[e.keyCode] = true;
                    switch(e.keyCode){
                        case 37: case 39: case 38:  case 40: // Arrow keys
                        case 32: e.preventDefault(); break; // Space
                        default: break; // do not block other keys
                    }
                },
            false);
            window.addEventListener('keyup',
                function(e){
                    keys[e.keyCode] = false;
                },
            false);

            //Lets add the keyboard controls now
            $(document).keydown(function (e) {
                var key = e.which;
                var td;
                if (nd.length) {
                    var td = nd[nd.length - 1];

                } else {
                    td = direction;
                }

                //We will add another clause to prevent reverse gear
                if (key == "37" && td != "right") nd.push("left");
                else if (key == "38" && td != "down") nd.push("up");
                else if (key == "39" && td != "left") nd.push("right");
                else if (key == "40" && td != "up") nd.push("down");

                //The snake is now keyboard controllable

            });

        });


        $(document).on('click', '.button-pad > button', function(e) {
            if ($(this).hasClass('left-btn')) {
                e = 37;
            }
            else if ($(this).hasClass('up-btn')) {
                e = 38;
            }
            else if ($(this).hasClass('right-btn')) {
                e = 39;
            }
            else if ($(this).hasClass('down-btn')) {
                e = 40;
            }
            $.Event("keydown", {keyCode: e});
        }); 

    });

})( jQuery );

FIDDLE

Answer 1

AND TIME

So basically you have some errors going on. Your first one is your styling. You really need to make your styles more flexible, but this will solve the right button problem I was having.

.button-pad > div {
    z-index: 9999;
    width: 50px;
}

http://jsfiddle.net/34oeacnm/8/

 $(document).on('click', '.button-pad .button', function(e) {
     var e = jQuery.Event("keydown");
     if ($(this).hasClass('left-btn')) {
        e.which = 37;
     }
     else if ($(this).hasClass('up-btn')) {
        e.which = 38;
     }
     else if ($(this).hasClass('right-btn')) {
         e.which = 39;
     }
     else if ($(this).hasClass('down-btn')) {
        e.which = 40;
     }
     $(document).trigger(e);
}); 

You had some of your selectors off. And I stole some information on how to trigger from Definitive way to trigger keypress events with jQuery .

Answer 2

Here is the code to add moile control to the snake game; (If you want the whole code for the snake game please comment);

//Here is javascript;

// left key
  function l() {
    if(snake.dx === 0) {
      snake.dx = -grid;
      snake.dy = 0;
    }
  }

  // up key
  function u() {
    if(snake.dy === 0) {
      snake.dy = -grid;
      snake.dx = 0;
    }
  }

  // right key 
  function r() {
    if(snake.dx === 0) {
      snake.dx = grid;
      snake.dy = 0;
    }
  }
  // down key 
  function d() {
    if(snake.dy === 0) {
      snake.dy = grid;
      snake.dx = 0;
    }
  }

Here is HTML;

<div>
  <button onclick="u()" type="button" id="U">U</button>
  <button onclick="l()" type="button" id="L">L</button>
  <button onclick="r()" type="button" id="R">R</button>
  <button onclick="d()" type="button" id="D">D</button>
</div>

Description: I simply added four buttons in the html page, created four functions in the js which will move snake as it should move in different directions and simply added them to the 'onclick' attribute of the different buttons respectively.