javascript_game/game.html at master · dhanushbathula747/javascript_game · GitHub

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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
<html>
<canvas id="gameCanvas" width="800" height="600"></canvas>


<script>
var canvas;
var canvasContext;
var ballX = 50;
var ballSpeedX = 10;// to control the ball speed.
var ballY = 50;
var ballSpeedY = 4; // to control ball speed(vertical).
var player1score=0;
var player2score=0;
const WINNING_SCORE=3;//keeping the game score constant

var showingWinScreen = false;
//Assigning the height and width
var paddle1Y = 250;
var paddle2Y = 250;
const PADDLE_HEIGHT = 100;
const PADDLE_WIDTH = 10;


//Mouse Movements
function calculateMousePos(evt) {
		var rect = canvas.getBoundingClientRect();
		var root = document.documentElement;
		var mouseX = evt.clientX - rect.left - root.scrollLeft;
		var mouseY = evt.clientY - rect.top - root.scrollTop;
		return {
				x:mouseX,
				y:mouseY
		};

}

function handleMouseClick(evt) {
	if(showingWinScreen) {
		player1score=0;
		player2score=0;
		showingWinScreen=false;
	}
}


window.onload = function() {
	canvas = document.getElementById('gameCanvas');
	canvasContext = canvas.getContext('2d');
	var framesPerSecond = 30;
	setInterval(callBoth, 1000/framesPerSecond); //this is time interval of 30frames for second.

	canvas.addEventListener('mousedown', handleMouseClick);

	canvas.addEventListener('mousemove',
		function(evt) {
			var mousePos = calculateMousePos(evt);
			paddle1Y = mousePos.y-(PADDLE_HEIGHT/2);
	});
}


function callBoth() {
		moveEverything();
		drawEverything();
}

function ballReset() {

	if(player1score >= WINNING_SCORE || player2score >= WINNING_SCORE){
		player1score=0;
		player2score=0;
		showingWinScreen = true;
	}

	ballSpeedX = -ballSpeedX;
	ballX = canvas.width/2;
	ballY = canvas.height/2;
}


function computermovement() {
	var paddle2YCenter = paddle2Y + (PADDLE_HEIGHT/2);
	if(paddle2YCenter < ballY) {
		paddle2Y+=6;
	}
	else if(paddle2YCenter > ballY+35){
		paddle2Y-=6
	}
}

//the motion of the ball is coded.
function moveEverything() {

	if(showingWinScreen) {
		return;
	}

	computermovement();

	ballX+=ballSpeedX;
	ballY+=ballSpeedY;
	if(ballX < 0) {
		if(ballY > paddle1Y && ballY< paddle1Y+PADDLE_HEIGHT) {
			ballSpeedX = -ballSpeedX;

			var deltaY = ballY-(paddle1Y+PADDLE_HEIGHT/2);
			ballSpeedY = deltaY *0.35;
		}
		else{
			player2score++;//must be BEFORE ballReset()
			ballReset();

		}
	}
	if(ballX > canvas.width) {
		if(ballY > paddle2Y && ballY< paddle2Y+PADDLE_HEIGHT) {
			ballSpeedX = -ballSpeedX;

			var deltaY = ballY-(paddle2Y+PADDLE_HEIGHT/2);
			ballSpeedY = deltaY *0.35;
		}
		else{
			player1score++;//must be BEFORE ballReset()
			ballReset();

		}
	}
	if(ballY < 0) {
		ballSpeedY = -ballSpeedY;
	}
	if(ballY > canvas.height) {
		ballSpeedY = -ballSpeedY;
	}
}

function drawNet() {
	for(var i=0;i<canvas.height;i+=40) {
		colorRect(canvas.width/2-1,i,2,20,'white');
	}
}

function drawEverything() {
	//next line fills the black color to the screen.
	colorRect(0,0,canvas.width,canvas.height,'black');


	if(showingWinScreen) {
		canvasContext.fillStyle = "white";

		if(player1score >= WINNING_SCORE){
			canvasContext.fillText("Left Player won!",350,200);
		}
		else if(player2score >= WINNING_SCORE){
			canvasContext.fillText("Right Player won!",350,200);
		}

		canvasContext.fillText("click to continue",350,500);
		return;
	}

	drawNet();

	//this is left player paddle.
	colorRect(0,paddle1Y,PADDLE_WIDTH,PADDLE_HEIGHT,'white');
	//this is right computer paddle.
	colorRect(canvas.width-PADDLE_WIDTH,paddle2Y,PADDLE_WIDTH,PADDLE_HEIGHT,'white');
	//this is the ball.
	colorcircle(ballX,ballY,10,'white');
	canvasContext.fillText(player1score,100,100);
	canvasContext.fillText(player2score,canvas.width-100,100);

}

function colorcircle(centerX,centerY,radius, drawColor) {
		canvasContext.fillStyle = drawColor;
		canvasContext.beginPath();
		canvasContext.arc(centerX, centerY, radius, 0,Math.PI*2, true);
		canvasContext.fill();
}

//function to create a new canvas contex.
function colorRect(leftX,topY, width, height, drawColor) {
		canvasContext.fillStyle = drawColor;
		canvasContext.fillRect(leftX,topY,width,height);

}
</script>
</html>