This examples demonstrates using transform.applyX and transform.applyY to apply the zoom behavior’s transform to data, rather than using an SVG transform. This is typically slower because it requires modifying all two thousand elements on each zoom, but it lets you customize the display on zoom, such as rendering circles that are the same size regardless of scale; consider using Canvas.
Last active
January 12, 2023 06:16
-
-
Save mbostock/2a39a768b1d4bc00a09650edef75ad39 to your computer and use it in GitHub Desktop.
Pan & Zoom IV
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
| license: gpl-3.0 | |
| redirect: https://observablehq.com/@d3/zoom-svg-rescaled |
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"> | |
| <svg width="960" height="500"></svg> | |
| <script src="https://d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| var svg = d3.select("svg"), | |
| width = +svg.attr("width"), | |
| height = +svg.attr("height"); | |
| var points = d3.range(2000).map(phyllotaxis(10)); | |
| var circle = svg.selectAll("circle") | |
| .data(points) | |
| .enter().append("circle") | |
| .attr("transform", function(d) { return "translate(" + d[0] + "," + d[1] + ")"; }) | |
| .attr("r", 2.5); | |
| svg.append("rect") | |
| .attr("width", width) | |
| .attr("height", height) | |
| .style("fill", "none") | |
| .style("pointer-events", "all") | |
| .call(d3.zoom() | |
| .scaleExtent([1 / 2, 4]) | |
| .on("zoom", zoomed)); | |
| function zoomed() { | |
| var transform = d3.event.transform; | |
| circle.attr("transform", function(d) { | |
| return "translate(" + transform.applyX(d[0]) + "," + transform.applyY(d[1]) + ")"; | |
| }); | |
| } | |
| function phyllotaxis(radius) { | |
| var theta = Math.PI * (3 - Math.sqrt(5)); | |
| return function(i) { | |
| var r = radius * Math.sqrt(i), a = theta * i; | |
| return [ | |
| width / 2 + r * Math.cos(a), | |
| height / 2 + r * Math.sin(a) | |
| ]; | |
| }; | |
| } | |
| </script> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment