Hungy Hungry snake

// Snake Game

​

// Global Vars for Spin-off

var tileSize = 25;

var framesPerMove = 5;

var snakeColorFront;

var snakeColorBack;

​

// Global vars for game mechanichs

var segments = [];

var keyStrokes = [];

var direction;

var position;

var lastTail;

var phase = 0.0;

var phaseInc = 1.0 / 64.0;

var possibleKeys;

​

// Scene

var sceneAttractIndex = 2;

var sceneInPlayIndex = 0;

var sceneGameOverIndex = 1;

var scene = sceneAttractIndex;

​

// Food

var food;

​

function setup() {

    createCanvas(600, 600);

    snakeColorFront = color(255);

    snakeColorBack = color(255, 0, 255);

    direction = createVector(0, tileSize);

    position = createVector(0, 0);

    lastTail = createVector();

    possibleKeys = [LEFT_ARROW, RIGHT_ARROW, UP_ARROW, DOWN_ARROW];

​

    food = {

        position: createVector(0, 0),

    };

    textAlign(CENTER, CENTER);

    ellipseMode(CORNER);

​

}

​

var drawFood = function() {

    push();

    colorMode(HSB);

    fill(255 * phase, 255, 255);

    noStroke();

    rect(food.position.x, food.position.y, tileSize, tileSize);

    pop();

};

​

var createFood = function() {

    var nTiles = width / tileSize;

​

    var onTail = false;

    do {

        onTail = false;

        var x = floor(random(nTiles)) * tileSize;

        var y = floor(random(nTiles)) * tileSize;

        food.position.set(x, y);

​

        var bodyLength = segments.length;

        for (var i = 0; i < bodyLength; i++) {

            if (segments[i].x === food.position.x && segments[i].y === food.position.y) {

                onTail = true;

                break;

            }

        }

    } while (onTail);

};

​

var init = function() {

    scene = sceneInPlayIndex;

    direction = createVector(0, tileSize);

    position = createVector(0, 0);

    segments = [position];

    keyStrokes = [];

    createFood();

};

​

var drawBody = function() {

    push();

    noStroke();

    var bodyLength = segments.length;

    var s = tileSize;

    for (var i = 0; i < bodyLength; i++) {

        fill(lerpColor(snakeColorFront, snakeColorBack, i / bodyLength));

        var offset = (tileSize - s) / 2.0;

        var segment = segments[i];

        rect(segment.x + offset, segment.y + offset, s, s);

        s *= 0.9;

        s = max(s, tileSize * 0.5);

    }

    pop();

};

​

var moveBody = function() {

    lastTail = segments[segments.length - 1].copy();

    position.add(direction);

    var bodyLength = segments.length;

​

    for (var i = bodyLength - 1; i > 0; i--) {

        var segment = segments[i - 1];

        segments[i] = segment.copy();

    }

    segments[0] = position.copy();

};

​

var eat = function() {

    var segment = segments[segments.length - 1];

    segments.push(segment.copy());

};

​

var checkEatingSelf = function() {

    var bodyLength = segments.length;

    for (var i = 1; i < bodyLength; i++) {

        var segment = segments[i];

        if (position.x === segment.x && position.y === segment.y) {

            return true;

        }

    }

    return false;

};

​

var checkFood = function() {

    if (frameCount % framesPerMove === 0) {

        if (position.x === food.position.x && position.y === food.position.y) {

            eat();

            createFood();

        }

    }

};

​

var updateBody = function() {

    if (frameCount % framesPerMove === 0) {

        moveBody();

        if (checkEatingSelf()) {

            scene = sceneGameOverIndex;

        }

        if (position.x === food.position.x && position.y === food.position.y) {

            eat();

            createFood();

        }

    }

};

​

var checkBoundary = function() {

    if (position.x < 0) {

        position.x = width - tileSize;

        segments[0] = position.copy();

    } else if (position.x >= width) {

        position.x = 0;

        segments[0] = position.copy();

    } else if (position.y >= height) {

        position.y -= height;

        segments[0] = position.copy();

    } else if (position.y < 0) {

        position.y += height;

        segments[0] = position.copy();

    }

};

​

var processKeyBuffer = function() {

    if (keyStrokes.length > 0) {

        var k = keyStrokes.shift();

​

        if (k === RIGHT_ARROW && direction.x !== -tileSize) {

            direction.set(tileSize, 0);

        }

        else if (k === LEFT_ARROW && direction.x !== tileSize) {

            direction.set(-tileSize, 0);

        }

        else if (k === UP_ARROW && direction.y !== tileSize) {

            direction.set(0, -tileSize);

        }

        else if (k === DOWN_ARROW && direction.y !== -tileSize) {

            direction.set(0, tileSize);

        }

    }

};

​

var sceneInPlay = function() {

    background("BOB");

    push();

    noStroke();

    fill(0);

    rect(0, 0, width, height);

    pop();

    processKeyBuffer();

    updateBody();

    checkBoundary();

    checkFood();

    drawBody();

    drawFood();

};

​

var sceneGameOver = function() {

    push();

    colorMode(HSB);

    fill(phase * 255, 255, 255);

    textAlign(CENTER, CENTER);

    textSize(50);

    text("GAME OVER", width / 2.0, 100);

    textSize(25);

    text("Your Score is ", width / 2.0, 200);

    text(segments.length, width / 2.0, 250);

    textSize(15);

    text("Click Mouse to Play Again", width / 2.0, 350);

    pop();

};

​

var sceneAttract = function() {

    push();

    background("blue");

    colorMode(HSB);

    fill(255 * phase, 255, 255);

    textSize(90);

    text("SNAKE", width / 2.0, 100);

​

    fill(255);

    textSize(30);

    text("How to Play:", width / 2.0, 200);

    textSize(15);

    text("Move Snake with Arrow Keys", width / 2.0, 250);

    text("Eat the Glowing Dots", width / 2.0, 270);

    text("Don't Eat Your Tail", width / 2.0, 290);

​

    fill(255 * phase, 255, 255);

    textSize(30);

    text("Click Mouse to Begin", width / 2.0, 350);

    pop();

};

​

var draw = function() {

    switch (scene) {

        case sceneAttractIndex:

            sceneAttract();

            break;

        case sceneInPlayIndex:

            sceneInPlay();

            break;

        case sceneGameOverIndex:

            sceneGameOver();

            break;

    }

​

    phase += phaseInc;

    if (phase >= 1.0) {

        phase -= 1.0;

    }

};

​

var keyPressed = function() {

    var k = key.toString();

    if (keyStrokes.length < 3 && possibleKeys.indexOf(keyCode) > -1) {

        keyStrokes.push(keyCode);

    }

};

​

var mouseClicked = function() {

    if (scene === sceneGameOverIndex) {

        init();

    }

    if (scene === sceneAttractIndex) {

        init();

    }

};