Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

restructure README #37

Merged
merged 1 commit into from
Oct 6, 2023
Merged

restructure README #37

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
96 changes: 7 additions & 89 deletions README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,94 +1,12 @@
# d3-path

Say you have some code that draws to a 2D canvas:
<a href="https://d3js.org"><img src="https://github.com/d3/d3/raw/main/docs/public/logo.svg" width="256" height="256"></a>

```js
function drawCircle(context, radius) {
context.moveTo(radius, 0);
context.arc(0, 0, radius, 0, 2 * Math.PI);
}
```
This module provides a common API for drawing in SVG and canvas.

The d3-path module lets you take this exact code and additionally render to [SVG](http://www.w3.org/TR/SVG/paths.html). It works by [serializing](#path_toString) [CanvasPathMethods](http://www.w3.org/TR/2dcontext/#canvaspathmethods) calls to [SVG path data](http://www.w3.org/TR/SVG/paths.html#PathData). For example:
## Resources

```js
const context = d3.path();
drawCircle(context, 40);
pathElement.setAttribute("d", context.toString());
```

Now code you write once can be used with both Canvas (for performance) and SVG (for convenience). For a practical example, see [d3-shape](https://github.com/d3/d3-shape).

## Installing

If you use npm, `npm install d3-path`. You can also download the [latest release on GitHub](https://github.com/d3/d3-path/releases/latest). In modern browsers, you can import d3-path from jsDelivr:

```html
<script type="module">

import {path} from "https://cdn.jsdelivr.net/npm/d3-path@3/+esm";

const p = path();
p.moveTo(1, 2);
p.lineTo(3, 4);
p.closePath();

</script>
```

For legacy environments, you can load d3-path’s UMD bundle from an npm-based CDN such as jsDelivr; a `d3` global is exported:

```html
<script src="https://cdn.jsdelivr.net/npm/d3-path@3"></script>
<script>

const path = d3.path();

</script>
```

## API Reference

<a name="path" href="#path">#</a> d3.<b>path</b>() · [Source](https://github.com/d3/d3-path/blob/master/src/path.js), [Examples](https://observablehq.com/@d3/d3-path)

Constructs a new path serializer that implements [CanvasPathMethods](http://www.w3.org/TR/2dcontext/#canvaspathmethods).

<a name="path_moveTo" href="#path_moveTo">#</a> <i>path</i>.<b>moveTo</b>(<i>x</i>, <i>y</i>)

Move to the specified point ⟨*x*, *y*⟩. Equivalent to [*context*.moveTo](http://www.w3.org/TR/2dcontext/#dom-context-2d-moveto) and SVG’s [“moveto” command](http://www.w3.org/TR/SVG/paths.html#PathDataMovetoCommands).

<a name="path_closePath" href="#path_closePath">#</a> <i>path</i>.<b>closePath</b>()

Ends the current subpath and causes an automatic straight line to be drawn from the current point to the initial point of the current subpath. Equivalent to [*context*.closePath](http://www.w3.org/TR/2dcontext/#dom-context-2d-closepath) and SVG’s [“closepath” command](http://www.w3.org/TR/SVG/paths.html#PathDataClosePathCommand).

<a name="path_lineTo" href="#path_lineTo">#</a> <i>path</i>.<b>lineTo</b>(<i>x</i>, <i>y</i>)

Draws a straight line from the current point to the specified point ⟨*x*, *y*⟩. Equivalent to [*context*.lineTo](http://www.w3.org/TR/2dcontext/#dom-context-2d-lineto) and SVG’s [“lineto” command](http://www.w3.org/TR/SVG/paths.html#PathDataLinetoCommands).

<a name="path_quadraticCurveTo" href="#path_quadraticCurveTo">#</a> <i>path</i>.<b>quadraticCurveTo</b>(<i>cpx</i>, <i>cpy</i>, <i>x</i>, <i>y</i>)

Draws a quadratic Bézier segment from the current point to the specified point ⟨*x*, *y*⟩, with the specified control point ⟨*cpx*, *cpy*⟩. Equivalent to [*context*.quadraticCurveTo](http://www.w3.org/TR/2dcontext/#dom-context-2d-quadraticcurveto) and SVG’s [quadratic Bézier curve commands](http://www.w3.org/TR/SVG/paths.html#PathDataQuadraticBezierCommands).

<a name="path_bezierCurveTo" href="#path_bezierCurveTo">#</a> <i>path</i>.<b>bezierCurveTo</b>(<i>cpx1</i>, <i>cpy1</i>, <i>cpx2</i>, <i>cpy2</i>, <i>x</i>, <i>y</i>)

Draws a cubic Bézier segment from the current point to the specified point ⟨*x*, *y*⟩, with the specified control points ⟨*cpx1*, *cpy1*⟩ and ⟨*cpx2*, *cpy2*⟩. Equivalent to [*context*.bezierCurveTo](http://www.w3.org/TR/2dcontext/#dom-context-2d-beziercurveto) and SVG’s [cubic Bézier curve commands](http://www.w3.org/TR/SVG/paths.html#PathDataCubicBezierCommands).

<a name="path_arcTo" href="#path_arcTo">#</a> <i>path</i>.<b>arcTo</b>(<i>x1</i>, <i>y1</i>, <i>x2</i>, <i>y2</i>, <i>radius</i>)

Draws a circular arc segment with the specified *radius* that starts tangent to the line between the current point and the specified point ⟨*x1*, *y1*⟩ and ends tangent to the line between the specified points ⟨*x1*, *y1*⟩ and ⟨*x2*, *y2*⟩. If the first tangent point is not equal to the current point, a straight line is drawn between the current point and the first tangent point. Equivalent to [*context*.arcTo](http://www.w3.org/TR/2dcontext/#dom-context-2d-arcto) and uses SVG’s [elliptical arc curve commands](http://www.w3.org/TR/SVG/paths.html#PathDataEllipticalArcCommands).

<a name="path_arc" href="#path_arc">#</a> <i>path</i>.<b>arc</b>(<i>x</i>, <i>y</i>, <i>radius</i>, <i>startAngle</i>, <i>endAngle</i>[, <i>anticlockwise</i>])

Draws a circular arc segment with the specified center ⟨*x*, *y*⟩, *radius*, *startAngle* and *endAngle*. If *anticlockwise* is true, the arc is drawn in the anticlockwise direction; otherwise, it is drawn in the clockwise direction. If the current point is not equal to the starting point of the arc, a straight line is drawn from the current point to the start of the arc. Equivalent to [*context*.arc](http://www.w3.org/TR/2dcontext/#dom-context-2d-arc) and uses SVG’s [elliptical arc curve commands](http://www.w3.org/TR/SVG/paths.html#PathDataEllipticalArcCommands).

<a name="path_rect" href="#path_rect">#</a> <i>path</i>.<b>rect</b>(<i>x</i>, <i>y</i>, <i>w</i>, <i>h</i>)

Creates a new subpath containing just the four points ⟨*x*, *y*⟩, ⟨*x* + *w*, *y*⟩, ⟨*x* + *w*, *y* + *h*⟩, ⟨*x*, *y* + *h*⟩, with those four points connected by straight lines, and then marks the subpath as closed. Equivalent to [*context*.rect](http://www.w3.org/TR/2dcontext/#dom-context-2d-rect) and uses SVG’s [“lineto” commands](http://www.w3.org/TR/SVG/paths.html#PathDataLinetoCommands).

<a name="path_toString" href="#path_toString">#</a> <i>path</i>.<b>toString</b>()

Returns the string representation of this *path* according to SVG’s [path data specification](http://www.w3.org/TR/SVG/paths.html#PathData).

<a name="pathRound" href="#pathRound">#</a> d3.<b>pathRound</b>(*digits* = 3) · [Source](https://github.com/d3/d3-path/blob/master/src/path.js), [Examples](https://observablehq.com/@d3/d3-path)

Like [d3.path](#path), except limits the digits after the decimal to the specified number of *digits*.
- [Documentation](https://d3js.org/d3-path)
- [Examples](https://observablehq.com/collection/@d3/d3-path)
- [Releases](https://github.com/d3/d3-path/releases)
- [Getting help](https://d3js.org/community)
Loading