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add main.js & main.html

main
Colin McMillen 5 years ago
parent
commit
3cd1b66965
  1. 33
      main.html
  2. 254
      main.js

33
main.html

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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>snej</title>
<style>
* { padding: 0; margin: 0; }
body { background: black; color: white; font-family: monospace; }
div { text-align: center; }
canvas {
background: magenta;
display: block;
margin: 0 auto;
margin-top: 8px;
margin-bottom: 8px;
padding: 1px;
image-rendering: pixelated;
}
</style>
</head>
<body>
<!-- SNES resolution: 256x224. 4x scaled: 1024 x 896. -->
<canvas id="canvas" width="256" height="224"></canvas>
<div id="debug"></div>
<button id="1x">1x</button>
<button id="2x">2x</button>
<button id="3x">3x</button>
<button id="4x">4x</button>
<button id="5x">5x</button>
<script src="main.js"></script>
</body>
</html>

254
main.js

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class Input {
constructor() {
this.left = false;
this.right = false;
this.up = false;
this.down = false;
this.a = false;
this.b = false;
this.x = false;
this.y = false;
this.l = false;
this.r = false;
this.select = false;
this.start = false;
window.addEventListener('gamepadconnected', this.gamepadConnected);
window.addEventListener('gamepaddisconnected', this.gamepadDisconnected);
}
update() {
// TODO: have a config screen instead of hard-coding the 8Bitdo SNES30 pad.
// TODO: handle connects / disconnects more correctly.
const gamepad = navigator.getGamepads()[0];
if (gamepad == null || !gamepad.connected || gamepad.axes.length < 2 ||
gamepad.buttons.length < 12) {
return;
}
this.left = gamepad.axes[0] < 0;
this.right = gamepad.axes[0] > 0;
this.up = gamepad.axes[1] < 0;
this.down = gamepad.axes[1] > 0;
this.a = gamepad.buttons[0].pressed;
this.b = gamepad.buttons[1].pressed;
this.x = gamepad.buttons[3].pressed;
this.y = gamepad.buttons[4].pressed;
this.l = gamepad.buttons[6].pressed;
this.r = gamepad.buttons[7].pressed;
this.select = gamepad.buttons[10].pressed;
this.start = gamepad.buttons[11].pressed;
debug(this.toString());
}
gamepadConnected(e) {
debug('gamepad connected! :)');
console.log('gamepad connected @ index %d: %d buttons, %d axes\n[%s]',
e.gamepad.index, e.gamepad.buttons.length, e.gamepad.axes.length,
e.gamepad.id);
}
gamepadDisconnected(e) {
debug('gamepad disconnected :(');
console.log('gamepad disconnected @ index %d:\n[%s]', e.gamepad.index,
e.gamepad.id);
}
toString() {
let result = '';
if (this.up) {
result += '^';
} else if (this.down) {
result += 'v';
} else {
result += '-';
}
if (this.left) {
result += '<';
} else if (this.right) {
result += '>';
} else {
result += '-';
}
result += ' ';
if (this.a) {
result += 'A';
}
if (this.b) {
result += 'B';
}
if (this.x) {
result += 'X';
}
if (this.y) {
result += 'Y';
}
if (this.l) {
result += 'L';
}
if (this.r) {
result += 'R';
}
if (this.select) {
result += 's';
}
if (this.start) {
result += 'S';
}
return result;
}
}
const input = new Input();
class Graphics {
constructor(canvas) {
this.canvas_ = canvas;
this.ctx_ = canvas.getContext('2d');
}
get width() {
return this.canvas_.width;
}
get height() {
return this.canvas_.height;
}
fill(color) {
this.ctx_.fillStyle = color;
this.ctx_.beginPath();
this.ctx_.rect(0, 0, this.canvas_.width, this.canvas_.height);
this.ctx_.fill();
this.ctx_.closePath();
}
circle(x, y, radius, color) {
this.ctx_.fillStyle = color;
this.ctx_.beginPath();
this.ctx_.arc(x, y, radius, 0, 2 * Math.PI)
this.ctx_.fill();
this.ctx_.closePath();
}
// TODO: replace with custom sprite-based text rendering.
text(string, x, y, size, color) {
this.ctx_.imageSmoothingEnabled = false;
this.ctx_.fillStyle = color;
this.ctx_.font = '' + size + 'px monospace';
this.ctx_.fillText(string, x, y);
}
}
class FpsCounter {
constructor() {
this.fps = 0;
this.frameTimes_ = new Array(60);
this.idx_ = 0;
}
update(timestampMs) {
if (this.frameTimes_[this.idx_]) {
const timeElapsed = (timestampMs - this.frameTimes_[this.idx_]) / 1000;
this.fps = this.frameTimes_.length / timeElapsed;
}
this.frameTimes_[this.idx_] = timestampMs;
this.idx_++;
if (this.idx_ == this.frameTimes_.length) {
this.idx_ = 0;
}
}
draw(gfx) {
gfx.text('FPS: ' + Math.round(this.fps), 8, 16, 16, 'yellow');
}
}
class World {
constructor() {
this.state_ = null;
this.fpsCounter_ = new FpsCounter();
this.input_ = new Input();
this.gamepadRenderer_ = new GamepadRenderer();
}
update(timestampMs) {
this.fpsCounter_.update(timestampMs);
this.input_.update();
}
draw(gfx) {
this.gamepadRenderer_.draw(gfx, this.input_);
this.fpsCounter_.draw(gfx);
}
}
class GamepadRenderer {
draw(gfx, input) {
const centerX = gfx.width / 2;
const centerY = gfx.height / 2;
gfx.fill('black');
// Select & Start
gfx.circle(centerX + 12, centerY, 8, input.start ? 'cyan' : 'grey');
gfx.circle(centerX - 12, centerY, 8, input.select ? 'cyan' : 'grey');
// Y X B A
gfx.circle(centerX + 48, centerY, 8, input.y ? 'cyan' : 'grey');
gfx.circle(centerX + 64, centerY - 16, 8, input.x ? 'cyan' : 'grey');
gfx.circle(centerX + 64, centerY + 16, 8, input.b ? 'cyan' : 'grey');
gfx.circle(centerX + 80, centerY, 8, input.a ? 'cyan' : 'grey');
// dpad
gfx.circle(centerX - 48, centerY, 8, input.right ? 'cyan' : 'grey');
gfx.circle(centerX - 64, centerY - 16, 8, input.up ? 'cyan' : 'grey');
gfx.circle(centerX - 64, centerY + 16, 8, input.down ? 'cyan' : 'grey');
gfx.circle(centerX - 80, centerY, 8, input.left ? 'cyan' : 'grey');
// L & R
gfx.circle(centerX + 30, centerY - 32, 8, input.r ? 'cyan' : 'grey');
gfx.circle(centerX - 30, centerY - 32, 8, input.l ? 'cyan' : 'grey');
}
}
function debug(message) {
const debugDiv = document.getElementById('debug');
debugDiv.innerText = message;
}
function loop(world, gfx) {
return timestampMs => {
world.update(timestampMs);
world.draw(gfx);
window.requestAnimationFrame(loop(world, gfx));
};
}
function setCanvasScale(scale) {
const snesWidth = 256;
const snesHeight = 224;
const canvas = document.getElementById('canvas');
canvas.style.width = '' + snesWidth * scale + 'px';
canvas.style.height = '' + snesHeight * scale + 'px';
}
function init() {
const world = new World();
const gfx = new Graphics(document.getElementById('canvas'));
document.getElementById('1x').onclick = () => setCanvasScale(1);
document.getElementById('2x').onclick = () => setCanvasScale(2);
document.getElementById('3x').onclick = () => setCanvasScale(3);
document.getElementById('4x').onclick = () => setCanvasScale(4);
document.getElementById('5x').onclick = () => setCanvasScale(5);
setCanvasScale(4);
window.requestAnimationFrame(loop(world, gfx));
debug('initialized!');
}
init();
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