Spaces:
Running
Running
File size: 2,832 Bytes
8c5907c |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 |
// Create the canvas
var canvas = document.createElement("canvas");
var ctx = canvas.getContext("2d");
canvas.width = 512;
canvas.height = 480;
document.body.appendChild(canvas);
// Background image
var bgReady = false;
var bgImage = new Image();
bgImage.onload = function () {
bgReady = true;
};
bgImage.src = "images/background.png";
// Hero image
var heroReady = false;
var heroImage = new Image();
heroImage.onload = function () {
heroReady = true;
};
heroImage.src = "images/hero.png";
// Monster image
var monsterReady = false;
var monsterImage = new Image();
monsterImage.onload = function () {
monsterReady = true;
};
monsterImage.src = "images/monster.png";
// Game objects
var hero = {
speed: 256 // movement in pixels per second
};
var monster = {};
var monstersCaught = 0;
// Handle keyboard controls
var keysDown = {};
addEventListener("keydown", function (e) {
keysDown[e.keyCode] = true;
}, false);
addEventListener("keyup", function (e) {
delete keysDown[e.keyCode];
}, false);
// Reset the game when the player catches a monster
var reset = function () {
hero.x = canvas.width / 2;
hero.y = canvas.height / 2;
// Throw the monster somewhere on the screen randomly
monster.x = 32 + (Math.random() * (canvas.width - 64));
monster.y = 32 + (Math.random() * (canvas.height - 64));
};
// Update game objects
var update = function (modifier) {
if (38 in keysDown) { // Player holding up
hero.y -= hero.speed * modifier;
}
if (40 in keysDown) { // Player holding down
hero.y += hero.speed * modifier;
}
if (37 in keysDown) { // Player holding left
hero.x -= hero.speed * modifier;
}
if (39 in keysDown) { // Player holding right
hero.x += hero.speed * modifier;
}
// Are they touching?
if (
hero.x <= (monster.x + 32)
&& monster.x <= (hero.x + 32)
&& hero.y <= (monster.y + 32)
&& monster.y <= (hero.y + 32)
) {
++monstersCaught;
reset();
}
};
// Draw everything
var render = function () {
if (bgReady) {
ctx.drawImage(bgImage, 0, 0);
}
if (heroReady) {
ctx.drawImage(heroImage, hero.x, hero.y);
}
if (monsterReady) {
ctx.drawImage(monsterImage, monster.x, monster.y);
}
// Score
ctx.fillStyle = "rgb(250, 250, 250)";
ctx.font = "24px Helvetica";
ctx.textAlign = "left";
ctx.textBaseline = "top";
ctx.fillText("Goblins caught: " + monstersCaught, 32, 32);
};
// The main game loop
var main = function () {
var now = Date.now();
var delta = now - then;
update(delta / 1000);
render();
then = now;
// Request to do this again ASAP
requestAnimationFrame(main);
};
// Cross-browser support for requestAnimationFrame
var w = window;
requestAnimationFrame = w.requestAnimationFrame || w.webkitRequestAnimationFrame || w.msRequestAnimationFrame || w.mozRequestAnimationFrame;
// Let's play this game!
var then = Date.now();
reset();
main(); |