| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * @typechecks |
| 7 | * |
| 8 | * Example usage: |
| 9 | * <Wedge |
| 10 | * outerRadius={50} |
| 11 | * startAngle={0} |
| 12 | * endAngle={360} |
| 13 | * fill="blue" |
| 14 | * /> |
| 15 | * |
| 16 | * Additional optional property: |
| 17 | * (Int) innerRadius |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | 'use strict'; |
| 22 | |
| 23 | var assign = Object.assign; |
| 24 | var React = require('react'); |
| 25 | var ReactART = require('react-art'); |
| 26 | |
| 27 | var createReactClass = require('create-react-class'); |
| 28 | |
| 29 | var Shape = ReactART.Shape; |
| 30 | var Path = ReactART.Path; |
| 31 | |
| 32 | /** |
| 33 | * Wedge is a React component for drawing circles, wedges and arcs. Like other |
| 34 | * ReactART components, it must be used in a <Surface>. |
| 35 | */ |
| 36 | var Wedge = createReactClass({ |
| 37 | displayName: 'Wedge', |
| 38 | |
| 39 | circleRadians: Math.PI * 2, |
| 40 | |
| 41 | radiansPerDegree: Math.PI / 180, |
| 42 | |
| 43 | /** |
| 44 | * _degreesToRadians(degrees) |
| 45 | * |
| 46 | * Helper function to convert degrees to radians |
| 47 | * |
| 48 | * @param {number} degrees |
| 49 | * @return {number} |
| 50 | */ |
| 51 | _degreesToRadians: function _degreesToRadians(degrees) { |
| 52 | if (degrees !== 0 && degrees % 360 === 0) { |
| 53 | // 360, 720, etc. |
| 54 | return this.circleRadians; |
| 55 | } else { |
| 56 | return (degrees * this.radiansPerDegree) % this.circleRadians; |
| 57 | } |
| 58 | }, |
| 59 | |
| 60 | /** |
| 61 | * _createCirclePath(or, ir) |
| 62 | * |
| 63 | * Creates the ReactART Path for a complete circle. |
| 64 | * |
| 65 | * @param {number} or The outer radius of the circle |
| 66 | * @param {number} ir The inner radius, greater than zero for a ring |
| 67 | * @return {object} |
| 68 | */ |
| 69 | _createCirclePath: function _createCirclePath(or, ir) { |
| 70 | var path = Path(); |
| 71 | |
| 72 | path |
| 73 | .move(0, or) |
| 74 | .arc(or * 2, 0, or) |
| 75 | .arc(-or * 2, 0, or); |
| 76 | |
| 77 | if (ir) { |
| 78 | path |
| 79 | .move(or - ir, 0) |
| 80 | .counterArc(ir * 2, 0, ir) |
| 81 | .counterArc(-ir * 2, 0, ir); |
| 82 | } |
| 83 | |
| 84 | path.close(); |
| 85 | |
| 86 | return path; |
| 87 | }, |
| 88 | |
| 89 | /** |
| 90 | * _createArcPath(sa, ea, ca, or, ir) |
| 91 | * |
| 92 | * Creates the ReactART Path for an arc or wedge. |
| 93 | * |
| 94 | * @param {number} startAngle The starting degrees relative to 12 o'clock |
| 95 | * @param {number} endAngle The ending degrees relative to 12 o'clock |
| 96 | * @param {number} or The outer radius in pixels |
| 97 | * @param {number} ir The inner radius in pixels, greater than zero for an arc |
| 98 | * @return {object} |
| 99 | */ |
| 100 | _createArcPath: function _createArcPath(startAngle, endAngle, or, ir) { |
| 101 | var path = Path(); |
| 102 | |
| 103 | // angles in radians |
| 104 | var sa = this._degreesToRadians(startAngle); |
| 105 | var ea = this._degreesToRadians(endAngle); |
| 106 | |
| 107 | // central arc angle in radians |
| 108 | var ca = sa > ea ? this.circleRadians - sa + ea : ea - sa; |
| 109 | |
| 110 | // cached sine and cosine values |
| 111 | var ss = Math.sin(sa); |
| 112 | var es = Math.sin(ea); |
| 113 | var sc = Math.cos(sa); |
| 114 | var ec = Math.cos(ea); |
| 115 | |
| 116 | // cached differences |
| 117 | var ds = es - ss; |
| 118 | var dc = ec - sc; |
| 119 | var dr = ir - or; |
| 120 | |
| 121 | // if the angle is over pi radians (180 degrees) |
| 122 | // we will need to let the drawing method know. |
| 123 | var large = ca > Math.PI; |
| 124 | |
| 125 | // TODO (sema) Please improve theses comments to make the math |
| 126 | // more understandable. |
| 127 | // |
| 128 | // Formula for a point on a circle at a specific angle with a center |
| 129 | // at (0, 0): |
| 130 | // x = radius * Math.sin(radians) |
| 131 | // y = radius * Math.cos(radians) |
| 132 | // |
| 133 | // For our starting point, we offset the formula using the outer |
| 134 | // radius because our origin is at (top, left). |
| 135 | // In typical web layout fashion, we are drawing in quadrant IV |
| 136 | // (a.k.a. Southeast) where x is positive and y is negative. |
| 137 | // |
| 138 | // The arguments for path.arc and path.counterArc used below are: |
| 139 | // (endX, endY, radiusX, radiusY, largeAngle) |
| 140 | |
| 141 | path |
| 142 | .move(or + or * ss, or - or * sc) // move to starting point |
| 143 | .arc(or * ds, or * -dc, or, or, large) // outer arc |
| 144 | .line(dr * es, dr * -ec); // width of arc or wedge |
| 145 | |
| 146 | if (ir) { |
| 147 | path.counterArc(ir * -ds, ir * dc, ir, ir, large); // inner arc |
| 148 | } |
| 149 | |
| 150 | return path; |
| 151 | }, |
| 152 | |
| 153 | render: function render() { |
| 154 | // angles are provided in degrees |
| 155 | var startAngle = this.props.startAngle; |
| 156 | var endAngle = this.props.endAngle; |
| 157 | if (startAngle - endAngle === 0) { |
| 158 | return null; |
| 159 | } |
| 160 | |
| 161 | // radii are provided in pixels |
| 162 | var innerRadius = this.props.innerRadius || 0; |
| 163 | var outerRadius = this.props.outerRadius; |
| 164 | |
| 165 | // sorted radii |
| 166 | var ir = Math.min(innerRadius, outerRadius); |
| 167 | var or = Math.max(innerRadius, outerRadius); |
| 168 | |
| 169 | var path; |
| 170 | if (endAngle >= startAngle + 360) { |
| 171 | path = this._createCirclePath(or, ir); |
| 172 | } else { |
| 173 | path = this._createArcPath(startAngle, endAngle, or, ir); |
| 174 | } |
| 175 | |
| 176 | return React.createElement(Shape, assign({}, this.props, {d: path})); |
| 177 | }, |
| 178 | }); |
| 179 | |
| 180 | module.exports = Wedge; |