Last active
March 22, 2023 13:34
-
-
Save mbostock/3e115519a1b495e0bd95 to your computer and use it in GitHub Desktop.
HCL Color Picker
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> | |
| canvas { | |
| float: left; | |
| width: 960px; | |
| height: 166px; | |
| border-bottom: solid 1px #fff; | |
| } | |
| </style> | |
| <canvas id="l" width="960" height="1"></canvas> | |
| <canvas id="a" width="960" height="1"></canvas> | |
| <canvas id="b" width="960" height="1"></canvas> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js" charset="utf-8"></script> | |
| <script> | |
| var white = d3.rgb("white"), | |
| black = d3.rgb("black"); | |
| var channels = { | |
| h: {extent: [0, 360], x: 480}, | |
| c: {extent: [0, 100], x: 480}, | |
| l: {extent: [0, 150], x: 480} | |
| }; | |
| var canvas = d3.selectAll("canvas") | |
| .data(d3.entries(channels)) | |
| .call(d3.behavior.drag().on("drag", dragged)) | |
| .each(render); | |
| function dragged(d) { | |
| d.value.x = Math.max(0, Math.min(this.width - 1, d3.mouse(this)[0])); | |
| canvas.each(render); | |
| } | |
| function render(d) { | |
| var width = this.width, | |
| context = this.getContext("2d"), | |
| image = context.createImageData(width, 1), | |
| i = -1; | |
| var current = d3.hcl( | |
| channels.h.extent[0] + channels.h.x / width * (channels.h.extent[1] - channels.h.extent[0]), | |
| channels.c.extent[0] + channels.c.x / width * (channels.c.extent[1] - channels.c.extent[0]), | |
| channels.l.extent[0] + channels.l.x / width * (channels.l.extent[1] - channels.l.extent[0]) | |
| ); | |
| for (var x = 0, v, c; x < width; ++x) { | |
| if (x === d.value.x) { | |
| c = white; | |
| } else if (x === d.value.x - 1) { | |
| c = black; | |
| } else { | |
| current[d.key] = d.value.extent[0] + x / (width - 1) * (d.value.extent[1] - d.value.extent[0]); | |
| c = d3.rgb(current); | |
| } | |
| image.data[++i] = c.r; | |
| image.data[++i] = c.g; | |
| image.data[++i] = c.b; | |
| image.data[++i] = 255; | |
| } | |
| context.putImageData(image, 0, 0); | |
| } | |
| </script> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment