I am having a problem where when I fire either left or right, once i move the character the bullets direction will change while its still fired. I am using the protagonist picture as the condition to either shoot right or left but i would like the bullet to keep firing in the fired direction even if i change the movement of the character
I am a beginner in Javascript and I'm using canvas to create a game for a college project.
if (moveBullet) {
let s = heroPic.src.substring(heroPic.src.lastIndexOf("/") + 1);
//alert(s);
if (s == "Protagenist_Right_Jet.png" || s == "Protagenist_Stand_Jet.png") {
bulletX += 20;
}
if (s == "Protagenist_Left_Jet.png") {
bulletX -= 20;
}
if (bulletX >= canvas.width) {
moveBullet = false;
bulletX = canvas.width + 50
bulletY = canvas.height + 50;
}
if (bulletX <= 0) {
moveBullet = false;
bulletX = canvas.width + 50
bulletY = canvas.height + 50;
}
}
Full Code
<!DOCTYPE html>
<body>
<div id="canvasesdiv" style="text-align: center;">
<canvas id="canvas1" width="800" height="500" tabIndex="0" style="background: url('Level 1.png');position: relative; display: block;">
</div>
<script>
var canvas = document.getElementById("canvas1");
var ctx = canvas.getContext("2d");
//get the animation frame depending on the browser engine
var requestAnimationFrame = window.requestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.msRequestAnimationFrame;
//Hero Attributes
var jetPackAudio = new Audio();
jetPackAudio.src = "Jetpack Sound.mp3";
var heroPic = new Image();
var heroX ;
var heroY ;
//Decides where the hero is looking
var heroRight = false;
var life = 3;
var heroWidth = 50 ;
var heroHeight = 50 ;
var gravity = 5;
heroX = 20;
heroY = 440;
heroPic.src = "Protagenist_Stand_Jet.png";
function drawHero(x,y)
{
ctx.drawImage(heroPic,x,y,heroWidth,heroHeight);
}
hitBottom = function() {
var rockbottom = canvas.height - heroHeight;
if (heroY > rockbottom) {
heroY = rockbottom;
}
}
// Key Attribute
var key = new Image();
key.src = "Key1.png"
var keyX ;
var keyY ;
var keyCounter = 0;
var keyWidth = 30 ;
var keyHeight = 30 ;
function drawKey()
{
ctx.drawImage(key,keyX,keyY,keyWidth,keyHeight);
}
var killCounter = 0 ;
var levelKillCounter;
// Monster 1 Attributes
var monster1 = new Image();
monster1.src = "Monster1_Left.png"
var m1MoveLeft = true;
var m1X ;
var m1Y ;
var m1Width = 50 ;
var m1Height = 50 ;
function drawMonster1()
{
ctx.drawImage(monster1,m1X,m1Y,m1Width,m1Height);
}
// Monster 2 Attributes
var monster2 = new Image();
monster2.src = "Monster 2_Right.png"
var m2MoveRight = true;
var m2X ;
var m2Y ;
var m2Width = 50 ;
var m2Height = 50 ;
function drawMonster2()
{
ctx.drawImage(monster2,m2X,m2Y,m2Width,m2Height);
}
// Monster 3 Attributes
var monster3 = new Image();
monster3.src = "Monster3_Right.png"
var m3MoveRight = true;
var m3X ;
var m3Y ;
var m3Width = 50 ;
var m3Height = 50 ;
function drawMonster3()
{
ctx.drawImage(monster3,m3X,m3Y,m3Width,m3Height);
}
// Hit Bottom
hitBottom = function() {
var rockbottom = canvas.height - heroHeight;
if (heroY > rockbottom) {
heroY = rockbottom;
}
}
//Bullet Attribute
var bulletX;
var bulletY;
const ammo = [];
var moveBullet = false;
var bulletImage = new Image();
bulletImage.src = 'Bullet.png';
function drawBullet(x,y)
{
ctx.drawImage(bulletImage,bulletX,bulletY);
}
//this function is used to detect a hit monster 1
function getDistanceHit1() {
var xRect = (m1X - bulletX);
var yRect = (m1Y - bulletY);
return Math.sqrt(Math.pow((xRect), 2) + Math.pow((yRect), 2));
}
//this function is used to detect a hit monster 2
function getDistanceHit2() {
var xRect = (m2X - bulletX);
var yRect = (m2Y - bulletY);
return Math.sqrt(Math.pow((xRect), 2) + Math.pow((yRect), 2));
}
//this function is used to detect a hit monster 3
function getDistanceHit3() {
var xRect = (m3X - bulletX);
var yRect = (m3Y - bulletY);
return Math.sqrt(Math.pow((xRect), 2) + Math.pow((yRect), 2));
}
//this function is used to detect if the player got the key
function getDistanceKey() {
var xRect = (keyX - heroX);
var yRect = (keyY - heroY);
return Math.sqrt(Math.pow((xRect), 2) + Math.pow((yRect), 2));
}
//configure the audio files
var fireAudio = new Audio();
fireAudio.src = "fire.mp3";
var hitAudio = new Audio();
hitAudio.src = "neck_snap.wav"
//Hero Movement
var rightPressed = false;
var leftPressed = false;
var upPressed = false;
var downPressed = false;
window.addEventListener("keydown", heroControl);
//Keyboard Cotrolls
function heroControl(event) { //event handler function
if (event.keyCode == 32) { //SPACE BAR PRESSED - fire gun
moveBullet = true;
fireAudio.play();
bulletX = heroX + 10;
bulletY = heroY + (heroHeight / 2);
console.log("BulletX = " + bulletX);
}
// 38 is up arrow, 87 is the W key
if (event.keyCode == 38 || event.keyCode == 87) { //Jump
upPressed = true;
console.log("HeroY = " + heroY);
}
// 39 is right arrow, 68 is thw D key
else if (event.keyCode == 39 || event.keyCode == 68) { //move Right
rightPressed = true;
console.log("Herox = " + heroX);
}
else if(event.keyCode == 37 || event.keyCode == 65) { // Move Left
leftPressed = true;
console.log("Herox = " + heroX);
}
else if(event.keyCode == 40 || event.keyCode == 83) { // Move Left
downPressed = true;
console.log("Heroy = " + heroY);
}
}
//Touch Controls
canvas.addEventListener("touchstart", handleTouchStart, false);
function handleTouchStart(touchEvent) { //event handler for touch events
var rect = canvas.getBoundingClientRect(); //to get canvas offsets
let touchX = touchEvent.changedTouches[0].clientX - rect.left;
let touchY = touchEvent.changedTouches[0].clientY - rect.top;
if (touchX <= canvas.width && touchX > canvas.width - 200) {
rightPressed = true;
}
if (touchX >= 0 && touchX < canvas.width - 600) {
leftPressed = true;
}
if (touchY >= 0 && touchY < canvas.height - 200) {
upPressed = true;
}
if (touchY <= canvas.height && touchY > canvas.height - 200) {
downPressed = true;
}
}
function moveHero() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
if(rightPressed) {
if(heroX < canvas.width - 53){
heroPic.src = "Protagenist_Right_Jet.png"
heroRight = true;
heroX = heroX + 10;
heroRight = true;
rightPressed = false;
}
else
{
rightPressed = false;
heroRight = false;
}
}
if(leftPressed) {
if(heroX > 0){
heroX = heroX - 10;
heroLeft = true;
heroPic.src = "Protagenist_Left_Jet.png";
bulletImage.src = "left_bullet.png";
leftPressed = false;
}
else
{
leftPressed = false;
heroLeft = false;
}
}
if(upPressed) {
if(heroY > 0){
heroY = heroY - 20;
heroStand = true;;
jetPackAudio.play();
heroPic.src = "Protagenist_Stand_Jet.png";
upPressed = false;
}
else
{
upPressed = false;
heroStand = false;;
}
}
if(downPressed) {
if(heroY < canvas.height){
heroPic.src = "Protagenist_Stand_Jet.png"
heroStand = true;
heroY = heroY + 10;
downPressed = false;
}
else
{
downPressed = false;
heroStand = false;
}
}
displayScoreArea();
drawHero(heroX,heroY);
drawMonster1();
drawMonster2();
drawMonster3();
drawKey();
drawBullet(bulletX,bulletY);
requestAnimationFrame(moveHero);
}
//Level Setter
var level = 2;
function setLvl()
{
if(level == 1)
{
canvas.style = "background: url('Level 1.png')";
levelKillCounter = 3;
}
else if(level == 2)
{
canvas.style = "background: url('Level 2.png')";
monster1.src = "Monster3_Right.png"
monster2.src = "Monster3_Right.png"
}
else if(level == 3)
{
canvas.style = "background: url('Level 3.png')";
}
}
var gameAudio = new Audio();
gameAudio.src = "Dungeon Theme.mp3"
function animation()
{
setTimeout(() => {
//animation code goes into this anonymous function handler
requestAnimationFrame(animation);
//clear the whole canvas area
ctx.clearRect(0, 0, canvas.width, canvas.height);
moveHero();
drawMonster1();
drawMonster2();
drawMonster3();
drawKey();
drawBullet(bulletX,bulletY);
monsterAnimate();
setLvl();
heroY = heroY + gravity;
if(moveBullet)
{
let s = heroPic.src.substring(heroPic.src.lastIndexOf("/") + 1);
//alert(s);
if(s == "Protagenist_Right_Jet.png" || s == "Protagenist_Stand_Jet.png")
{
bulletX +=20;
}
if(s == "Protagenist_Left_Jet.png")
{
bulletX -=20;
}
if(bulletX >= canvas.width)
{
moveBullet = false;
bulletX = canvas.width + 50
bulletY = canvas.height +50;
}
if(bulletX <= 0)
{
moveBullet = false;
bulletX = canvas.width + 50
bulletY = canvas.height +50;
}
console.log(getDistanceHit1());
if (getDistanceHit1() <= 30 ||
getDistanceHit2() <= 30 ||
getDistanceHit3() <= 30 )
{
//Delete Monster
if(getDistanceHit1() <= 30)
{
m1X = 1000;
m1Y = 1000;
}
if(getDistanceHit2() <= 30)
{
m2X = 1000;
m2Y = 1000;
}
if(getDistanceHit3() <= 30)
{
m3X = 1000;
m3Y = 1000;
}
//increase the hit count
killCounter++;
//we have a hit
moveBullet = false;
//play the hitAudio
hitAudio.play();
//Reset Bullet
bulletX = canvas.width + 50
bulletY = canvas.height +50;
}
}
if(killCounter == 3)
{
keyX = canvas.width / 2;
keyY = 150;
}
if(getDistanceKey() <= 10)
{
keyCounter = 1;
keyX = 1000;
keyY = 1000;
}
//level progression flow - check of level objectives are met
if (level == 1 && keyCounter == 1 && heroX >= 700 & heroY >= 50) {
alert("Level 1 completed. Starting Level 2...");
level = 2;
killCounter = 0; //reset
keyCounter = 0;//reset
m1X = 700;
m1Y = 370;
m2X = 100;
m2Y = 320;
m3X = 100;
m3Y = 170;
}
else if (level == 2 && keyCounter == 1 && heroX == 700 & heroY == 50) {
alert("Level 2 completed. Starting Level 3...");
level = 3;
killCounter = 0; //reset
keyCounter = 0;//reset
}
else if (level == 3 && currentLevelHits == 4) {
//last level
var playAgain = confirm("Game completed. Play again?");
if (playAgain)
window.location.reload(true); //force reload
else
stopAnimation = true;
}
//gameAudio.play();
displayScoreArea();
hitBottom();
},100)
}
m1X = 700;
m1Y = 370;
m2X = 100;
m2Y = 320;
m3X = 100;
m3Y = 170;
function monsterAnimate()
{
//Movement for level 1
if(level == 1)
{
if(m1MoveLeft)
{
m1X -= 10
}
else if(!m1MoveLeft)
{
m1X += 10
}
if(m2MoveRight)
{
m2X += 10
}
else if(!m2MoveRight)
{
m2X -= 10
}
if(m3MoveRight)
{
m3X +=10
}
else if(!m3MoveRight)
{
m3X -= 10
}
if(m1X == 420)
{
m1MoveLeft = false;
monster1.src ="Monster 1_Right.png"
}
else if(m1X == 700)
{
m1MoveLeft = true;
monster1.src ="Monster1_Left.png"
}
if(m2X == 310)
{
m2MoveRight = false;
monster2.src ="Monster2_left.png"
}
else if(m2X == 100)
{
m2MoveRight = true;
monster2.src ="Monster 2_Right.png"
}
if(m3X == 310)
{
m3MoveRight = false;
monster3.src ="Monster 3_left.png"
}
else if(m3X == 100)
{
m3MoveRight = true;
monster3.src ="Monster3_Right.png"
}
}
//Movement for level 2
if(level == 2)
{
if(m1MoveLeft)
{
m1X -= 20
}
else if(!m1MoveLeft)
{
m1X += 20
}
if(m2MoveRight)
{
m2X += 20
}
else if(!m2MoveRight)
{
m2X -= 20
}
if(m3MoveRight)
{
m3X +=20
}
else if(!m3MoveRight)
{
m3X -= 20
}
if(m1X == 420)
{
m1MoveLeft = false;
monster1.src ="Monster 1_Right.png"
}
else if(m1X == 700)
{
m1MoveLeft = true;
monster1.src ="Monster1_Left.png"
}
if(m2X == 600)
{
m2MoveRight = false;
monster2.src ="Monster2_left.png"
}
else if(m2X == 100)
{
m2MoveRight = true;
monster2.src ="Monster 2_Right.png"
}
if(m3X == 500)
{
m3MoveRight = false;
monster3.src ="Monster 3_left.png"
}
else if(m3X == 100)
{
m3MoveRight = true;
monster3.src ="Monster3_Right.png"
}
}
}
// Create gradient
var gradient = ctx.createLinearGradient(0, 0, canvas.width, 0);
gradient.addColorStop("0", "black");
gradient.addColorStop("0.5", "red");
gradient.addColorStop("1.0", "white");
//Draw Score Area
function displayScoreArea() {
ctx.font = "40px Arial";
ctx.strokeStyle = gradient;
ctx.fillStyle = gradient;
ctx.strokeText(killCounter, 380, 60);
ctx.strokeText(life, 65, 45);
ctx.strokeText(keyCounter, 65, 90);
}
animation();
function moveup()
{
upPressed = true;
}
function movedown()
{
downPressed = true;
}
function moveright()
{
rightPressed = true;
}
function moveleft()
{
leftPressed = true;
}
function shootGun()
{
moveBullet = true;
fireAudio.play();
bulletX = heroX + 10;
bulletY = heroY + (heroHeight / 2);
console.log("BulletX = " + bulletX);
}
</script>
<div style="text-align:center;width:900px;">
<button style="width: 100px; height: 60px;" onclick="moveup()">UP</button><br><br>
<button style="width: 100px; height: 60px;" onclick="moveleft()">LEFT</button>
<button style="width: 100px; height: 60px; margin-left: 20px;" onclick="moveright()">RIGHT</button><br><br>
<button style="width: 100px; height: 60px;" onclick="movedown()">DOWN</button>
<button style="width: 100px; height: 60px;" onclick="shootGun()">SHOOT</button>
</div>
</body>
</html>
Using objects would be one (of many) steps in the right direction. Even without them, you could:
In your bullet variable creation
In your hero control function, where the firing action currently takes place, initialize your bullet properties once
In your animation function, where this currently takes place, update your bullet position according to its velocity
There are lots of things I would refactor in your current setup, but this should get you moving on your current problem.
And a quick example of a very simple object: