void main(){
gl_FragColor = v_color;
}
`;
webgl.vertexShader = gl.createShader(gl.VERTEX_SHADER);
gl.shaderSource(webgl.vertexShader, webgl.vertexShaderSource);
gl.compileShader(webgl.vertexShader);
webgl.fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
gl.shaderSource(webgl.fragmentShader, webgl.fragmentShaderSource);
gl.compileShader(webgl.fragmentShader);
webgl.shaderProgram = gl.createProgram();
gl.attachShader(webgl.shaderProgram, webgl.vertexShader);
gl.attachShader(webgl.shaderProgram, webgl.fragmentShader);
gl.linkProgram(webgl.shaderProgram);
gl.useProgram(webgl.shaderProgram);
webgl.dataAttribLoc = gl.getAttribLocation(webgl.shaderProgram, 'a_data');
webgl.dataBuffer = gl.createBuffer();
gl.enableVertexAttribArray(webgl.dataAttribLoc);
gl.bindBuffer(gl.ARRAY_BUFFER, webgl.dataBuffer);
gl.vertexAttribPointer(webgl.dataAttribLoc, 4, gl.FLOAT, false, 0, 0);
webgl.resUniformLoc = gl.getUniformLocation(webgl.shaderProgram, 'u_res');
webgl.modeUniformLoc = gl.getUniformLocation(webgl.shaderProgram, 'u_mode');
gl.viewport(0, 0, w, h);
gl.uniform2f(webgl.resUniformLoc, w, h);
gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
gl.enable(gl.BLEND);
gl.lineWidth(opts.projectileLineWidth);
webgl.data = [];
webgl.clear = function() {
gl.uniform1i(webgl.modeUniformLoc, 1);
var a = .1;
webgl.data = [-1, -1, 0, a,
1, -1, 0, a, -1, 1, 0, a, -1, 1, 0, a,
1, -1, 0, a,
1, 1, 0, a
];
webgl.draw(gl.TRIANGLES);
gl.uniform1i(webgl.modeUniformLoc, 0);
webgl.data.length = 0;
}
webgl.draw = function(glType) {
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(webgl.data), gl.STATIC_DRAW);
gl.drawArrays(glType, 0, webgl.data.length / 4);
}
var fireworks = [],
tick = 0,
sins = [],
coss = [],
maxShardsParFirework = opts.baseShardsParFirework + opts.addedShardsParFirework,
tau = 6.283185307179586476925286766559;
for (var i = 0; i < maxShardsParFirework; ++i) {
sins[i] = Math.sin(tau * i / maxShardsParFirework);
coss[i] = Math.cos(tau * i / maxShardsParFirework);
}
function Firework() {
this.reset();
this.shards = [];
for (var i = 0; i < maxShardsParFirework; ++i)
this.shards.push(new Shard(this));
}
Firework.prototype.reset = function() {
var angle = -Math.PI / 2 + (Math.random() - .5) * opts.fireworkAngleSpan,
vel = opts.baseFireworkVel + opts.addedFireworkVel * Math.random();
this.mode = 0;
this.vx = vel * Math.cos(angle);
this.vy = vel * Math.sin(angle);
this.x = Math.random() * w;
this.y = h;
this.hue = tick * opts.initHueMultiplier;
}
Firework.prototype.step = function() {
if (this.mode === 0) {
var ph = this.hue,
px = this.x,
py = this.y;
this.hue += opts.runHueAdder;
