Last active
June 6, 2016 15:43
-
-
Save EmilienDupont/53f3a36a7ffd68662dbff421e83d89e5 to your computer and use it in GitHub Desktop.
Fountain
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <style> | |
| </style> | |
| <body> | |
| <script src="//d3js.org/d3.v3.min.js"></script> | |
| <script> | |
| var width = 960, | |
| height = 500, | |
| g = 5, // Low gravity for visualization | |
| then = Date.now(); | |
| var scale_x = d3.scale.linear() | |
| .domain([0, width]) | |
| .range([0, 5]); | |
| var scale_y = d3.scale.linear() | |
| .domain([0, height]) | |
| .range([5 * height/width, 0]); | |
| var svg = d3.select("body") | |
| .append("svg") | |
| .attr("width", width) | |
| .attr("height", height); | |
| /* Create droplets with random initial velocities */ | |
| function create_droplets(num_droplets) { | |
| var droplets = []; | |
| for (i = 0; i < num_droplets; i++) { | |
| var v_x_init = 2.5 * (Math.random() - 0.5), | |
| v_y_init = 1.5 * Math.random() + 3.5, | |
| x_init = scale_x(width/2), | |
| y_init = scale_y(height), | |
| time_delay = 2 * Math.random(), | |
| period = v_y_init / 2.5; | |
| droplets.push({ "vel_init": {"x" : v_x_init, "y" : v_y_init}, | |
| "pos_init": {"x" : x_init, "y" : y_init}, | |
| "time_delay": time_delay, | |
| "period": period}); | |
| } | |
| return droplets; | |
| } | |
| /* Returns (x,y) position at time t given inital velocity and position */ | |
| function position(pos_init, vel_init, t) { | |
| var x_pos = vel_init.x * t + pos_init.x, | |
| y_pos = -.5 * g * t * t + vel_init.y * t + pos_init.y; | |
| return {"x" : x_pos, "y" : y_pos}; | |
| } | |
| droplets_data = create_droplets(200); | |
| var circles = svg.selectAll("circle") | |
| .data(droplets_data) | |
| .enter() | |
| .append("circle") | |
| .attr("cx", function(d) { return scale_x.invert(position(d.pos_init, d.vel_init, 0).x); }) | |
| .attr("cy", function(d) { return scale_y.invert(position(d.pos_init, d.vel_init, 0).y); }) | |
| .attr("r", function(d) { return 5 + 5 * Math.random(); }) | |
| .attr("fill", function(d) { return d3.hsl(150 + Math.floor(50 * Math.random()), 1, .5); } ); | |
| function redraw(t) { | |
| circles.attr("cx", function(d) { return scale_x.invert(position(d.pos_init, d.vel_init, Math.max(0, t - d.time_delay) % d.period ).x); }) | |
| .attr("cy", function(d) { return scale_y.invert(position(d.pos_init, d.vel_init, Math.max(0, t - d.time_delay) % d.period ).y); }) | |
| .attr("fill-opacity", function (d) { return 1 - Math.max(0, t - d.time_delay) % d.period /d.period; }); | |
| } | |
| d3.timer(function() { | |
| var time = (Date.now() - then)/1000; | |
| redraw(time); | |
| }) | |
| </script> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment