# mapbox-gl-draw-bezier-curve-mode

A [mapbox gl draw](https://www.npmjs.com/package/@mapbox/mapbox-gl-draw) mode to draw and edit bezier curves.


# Demo
 Demo page : https://mapbox-gl-draw-bezier-curve-demo.numix.fr

## Preview
![Demo](demo/md-resources/BezierDraw-demo.gif)

# Usage

## Bezier Curve Draw mode
Use the Bezier tool to enter in Bezier Curve Draw mode : 

![Demo](demo/md-resources/bezier-tool-icon.png)

**Alt + Drag with Left click** to create nodes with bezier handles.\
Hit **Enter** or **Left click on the last node** to finish the curve

![Create nodes with handles](demo/md-resources/BezierDraw-CreateNodesWithHandles.gif)

**Left mouse click** to create nodes **without** handles (same as line string tool).\
Bezier Curves can have nodes with or without handles

![Create nodes with handles](demo/md-resources/BezierDraw-CreateNodesWithoutHandles.gif)



Close a curve by connecting the last node to the first one :

![Close curve](demo/md-resources/BezierDraw-CreateClosedCurve.gif)

Remove last added nodes with **Right click**

![Remove last added nodes](demo/md-resources/BezierDraw-RemoveLastNodes.gif)

---

## Bezier Curve Editing 
To edit a bezier curve, enter in direct mode.

Select a node, then **drag with left click** to move bezier handles :

![Edit handles](demo/md-resources/BezierDraw-EditHandles.gif)


**Break bezier handle symmetry**\
Select a node, then **Alt + Drag with left click** on a bezier handle :

![Break handle symetry](demo/md-resources/BezierDraw-BreakHandleSymmetry.gif)

**Toggle node handles**\
When bezier handles are visible, **Alt + Left Click** on the node will remove the handles :

![Toggle node remove handles](demo/md-resources/BezierDraw-ToggleNodeRemoveHandles.gif)

When bezier handles are not visible **Alt + Drag with left click** on the node will show the handles :

![Toggle node hcreate andles](demo/md-resources/BezierDraw-ToggleNodeCreateHandles.gif)

**Create new nodes in between**\
In direct mode, click on a midpoint to create a new node inside the curve :

![Create new nodes](demo/md-resources/BezierDraw-CreateNewNodes.gif)

**Delete node**\
Select a node and hit **Delete key**

---

## Bezier Polygon mode

![Demo](demo/md-resources/bezier-polygon-tool-icon.png)

In addition to Bezier lines, a filled Bezier Polygon variant is available. Use the same draw mode with an option flag:
See the "To Use" section below for a concise code example.

- Closed Bezier polygons are converted to standard Mapbox GL Draw Polygon features so fill is rendered consistently.
- Bezier polygons are editable like Bezier lines (move points/handles, insert midpoints).

## Combine/Uncombine extended support
Combining / uncombining bezier curves is supported. In Direct mode there are some additional features :

#### In Direct mode, combine two vertices from a different bezier curve
If two bezier curves where previously combined, its possible to combine them into a single curve by selecting two vertices.

To do so :
- Select two curves
- Hit Combine to group them
- Enter in Direct mode and select two vertices
- Hit Combine again to link the two curves together

![Combine Two Separate Curvess](demo/md-resources/BezierDraw-CombineTwoSeparateCurves.gif)

**Close a curve**\
Close the curve by combining the first and last node in direct mode.

![Close Curve](demo/md-resources/BezierDraw-CloseCurve.gif)

**Open a curve**\
When a curve is closed, open it by uncombining a single vertex. It will be splitted in two separate vertices allowing the curve to be open again.

![Open Curve](demo/md-resources/BezierDraw-OpenCurve.gif)


**Split curves**\
Select vertices on a non closed curve to split it in multiple curves. The result will be a combined curve.\
Uncombine it in **simple_select mode** to be able to move each curve independently.

![Split Curves](demo/md-resources/BezierDraw-SplitCurves.gif)

# Installation
## To Install: 
#### Yarn:
    yarn add mapbox-gl-draw-bezier-curve-mode
#### Npm:
    npm install mapbox-gl-draw-bezier-curve-mode
    
## To Use:
```js
import {
  SimpleSelectModeBezierOverride, 
  DirectModeBezierOverride, 
  DrawBezierCurve, 
  customStyles,
} from 'mapbox-gl-draw-bezier-curve-mode';

var draw = new MapboxDraw({
    displayControlsDefault: false,
    userProperties: true,
    modes: {
    ...MapboxDraw.modes,
    simple_select: SimpleSelectModeBezierOverride,
    direct_select: DirectModeBezierOverride,
    draw_bezier_curve: DrawBezierCurve,
    },
    styles: customStyles
});

var map = new mapboxgl.Map({
  container: 'map',
  style: 'mapbox://styles/mapbox/streets-v8',
  center: [2.45, 46.59],
  zoom: 5.8
});

map.addControl(Draw)

// Bezier line (default)
draw.changeMode('draw_bezier_curve');

// Bezier polygon (auto-closes when ≥ 3 points, renders with fill)
draw.changeMode('draw_bezier_curve', { isPolygon: true });
```

See [demo](https://github.com/Jeff-Numix/mapbox-gl-draw-bezier-curve-mode/tree/master/demo) package for a full example.

More information about mapbox-gl-draw :
* [API](https://github.com/mapbox/mapbox-gl-draw/blob/main/docs/API.md)
* [Draw Modes](https://github.com/mapbox/mapbox-gl-draw/blob/main/docs/MODES.md)
* [Examples](https://github.com/mapbox/mapbox-gl-draw/blob/main/docs/EXAMPLES.md)
# Dependencies
[mapbox-gl](https://www.npmjs.com/package/mapbox-gl)

[mapbox-gl-draw](https://www.npmjs.com/package/@mapbox/mapbox-gl-draw)

[mathjs](https://www.npmjs.com/package/mathjs)



# Changelog 
### v1.1.0
* Add Bezier Polygon mode via single draw mode: `draw.changeMode('draw_bezier_curve', { isPolygon: true })`

### v1.0.0
* First version
### v1.0.1
* Demo project : Added an information box to display controls

# Known issues
### v1.0.0 
* When combining/uncombining vertices in direct mode, the shape will not refresh until you move or click anywhere else.

If you find an issue, please refer : https://github.com/Jeff-Numix/mapbox-gl-draw-bezier-curve-mode/issues
# Licence
MIT © JeffSebrechts

# Credits
Developed by Jeff Sebrechts
* linkedin : [linkedin](https://www.linkedin.com/in/jeff-sebrechts/)
* website : [wwww.numix.fr](https://www.numix.fr)