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@yakkomajuri
Last active Jul 5, 2020
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/*
Original Code Credits: Chris DeLeon of HomeTeam GameDev
Modified by: Yakko Majuri
*/
'use strict'
let canvas, ctx;
window.onload = function () {
canvas = document.getElementById("game-board");
ctx = canvas.getContext("2d");
document.addEventListener("keydown", keyPush);
setInterval(game, 1000 / 15);
let instructionsBtn = document.getElementById("instructions-btn");
instructionsBtn.addEventListener("click", showInstructions);
}
let score = 0;
let highScore = 0;
let px = 10;
let py = 10;
let gs = 20;
let tc = 20;
let ax = 15;
let ay = 15;
let xv = 0;
let yv = 0;
let trail = [];
let tail = 5;
let paused = false
let pre_pause = [0, 0]
function game() {
px += xv;
py += yv;
if (px < 0) {
px = tc - 1;
}
if (px > tc - 1) {
px = 0;
}
if (py < 0) {
py = tc - 1;
}
if (py > tc - 1) {
py = 0;
}
ctx.fillStyle = "black";
ctx.fillRect(0, 0, canvas.width, canvas.height);
ctx.fillStyle = "lime";
for (var i = 0; i < trail.length; ++i) {
ctx.fillRect(trail[i].x * gs, trail[i].y * gs, gs - 2, gs - 2);
if (trail[i].x == px && trail[i].y == py) {
tail = 5;
score = paused ? score : 0;
}
}
trail.push({ x: px, y: py });
while (trail.length > tail) {
trail.shift();
}
if (ax == px && ay == py) {
++score;
++tail;
ax = Math.floor(Math.random() * tc);
ay = Math.floor(Math.random() * tc);
}
ctx.fillStyle = "red";
ctx.fillRect(ax * gs, ay * gs, gs - 2, gs - 2);
updateScore(score)
}
function updateScore(newScore) {
document.getElementById("score").innerHTML = "Score: " + String(newScore);
if (newScore > highScore) {
document.getElementById("high-score").innerHTML = "High Score: " + String(newScore);
highScore = newScore;
}
}
function keyPush(evt) {
if (!paused) {
switch (evt.keyCode) {
case 37:
xv = -1; yv = 0;
break;
case 38:
xv = 0; yv = -1;
break;
case 39:
xv = 1; yv = 0;
break;
case 40:
xv = 0; yv = 1;
break;
}
}
if (evt.keyCode === 32) {
let temp = [xv, yv];
xv = pre_pause[0];
yv = pre_pause[1];
pre_pause = [...temp];
paused = !paused;
}
}
function showInstructions() {
window.alert("Use the arrow keys to move and press spacebar to pause the game.");
}
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