Three. js source code annotation (19th) extras/geometries/CircleGeometry. js, three. jsgeometries

Three. js source code annotation (19th) extras/geometries/CircleGeometry. js, three. jsgeometries

Wuji (http://blog.csdn.net/omni360)

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Reprinted please keep this sentence: Wuji-this blog focuses on Agile development and mobile and IOT device research: data visualization, GOLANG, Html5, WEBGL, THREE. JS. Otherwise, the post from this blog will not be reprinted or reprinted. Thank you for your cooperation.

I also just started learning. Sorry for the errors in many places.

The following code is a comment on the extras/geometries/CircleGeometry. JS file in the THREE. js source code file.

More updates in: https://github.com/omni360/three.js.sourcecode

/*** @ Author hughes * // CircleGeometry is used to create a circular object in a three-dimensional space, A circular object is a polygon object that is formed by splicing triangles specified by the segments parameter around the center of a circle. ///// usage: var radius = 5, segments = 32; // var geometry = new THREE. circleGeometry (radius, segments); // var material = new THREE. meshBasicMaterial ({color: 0x00ff00}); // var circle = new THREE. mesh (geometry, material); // scene. add (circle); * // <summary> CircleGeometry </summary> // <param name = "Radius" type = "float"> radius of a circular (polygon) object, the default value is 50. </param> // <param name = "segments" type = "int"> optional. The number of line segments (edges) of a circle (polygon ), the default value is 8 </param> /// <param name = "thetaStart" type = "int"> (optional) the starting point of the circle (polygon, the default value is 0 </param> /// <param name = "thetaLength" type = "int"> (optional) indicates the end point of the circle (polygon). The default value is Math. PI * 2 </param> THREE. circleGeometry = function (radius, segments, thetaStart, thetaLength) {THREE. geometry. call (this); this. parameters = {Radius: radius, segments: segments, thetaStart: thetaStart, thetaLength: thetaLength}; radius = radius | 50; // circle (polygon) radius. The default value is 50. segments = segments! = Undefined? Math. max (3, segments): 8; // number of segments in a circle or polygon. The minimum value is 3. If the segments attribute is not set, the value is initialized to 8. thetaStart = thetaStart! = Undefined? ThetaStart: 0; // the starting point of the circle or polygon. The default value is 0. thetaLength = thetaLength! = Undefined? ThetaLength: Math. PI * 2; // the end point of the circle (polygon). The default value is Math. PI * 2 // the following code generates uv coordinates and point information for the circle (polygon. var I, uvs = [], center = new THREE. vector3 (), centerUV = new THREE. vector2 (0.5, 0.5); this. vertices. push (center); uvs. push (centerUV); for (I = 0; I <= segments; I ++) {// traverse to form a circle (polygon) var vertex = new THREE. vector3 (); var segment = thetaStart + I/segments * thetaLength; // obtain the vertex angle that forms the circular (polygon) side or line segment. x = radius * Math. cos (segment); // calculate the x coordinate vertex Based on the radius and angle values. y = radius * Math. sin (segment); // calculate the y coordinate based on the radius and angle value. this. vertices. push (vertex); // Add to vertex array. uvs. push (new THREE. vector2 (vertex. x/radius + 1)/2, (vertex. y/radius + 1)/2); // Add the uvs coordinate information} var n = new THREE. vector3 (0, 0, 1); for (I = 1; I <= segments; I ++) {// traverse a circle (polygon) this. faces. push (new THREE. face3 (I, I + 1, 0, [n. clone (), n. clone (), n. clone ()]); // generate the triangle vertex index this. faceVertexUvs [0]. push ([uvs [I]. clone (), uvs [I + 1]. clone (), centerUV. clone ()]); // generate The uvs coordinates of the triangle surface in the same order as the vertex index of the triangle surface} this. computeFaceNormals (); // calculate the surface normal this. boundingSphere = new THREE. sphere (new THREE. vector3 (), radius); // generates the spherical boundary of the circular (polygon) object .}; /*************************************** * ************ the method attribute definition of the CircleGeometry object is as follows, it inherits from the Geometry object. **************************************** * *********/THREE. circleGeometry. prototype = Object. create (THREE. geometry. prototype );

Wuji (http://blog.csdn.net/omni360)

This article follows the "signature-non-commercial use-consistency" creation public agreement

Reprinted please keep this sentence: Wuji-this blog focuses on Agile development and mobile and IOT device research: data visualization, GOLANG, Html5, WEBGL, THREE. JS. Otherwise, the post from this blog will not be reprinted or reprinted. Thank you for your cooperation.

The following code is a comment on the extras/geometries/CircleGeometry. JS file in the THREE. js source code file.

More updates in: https://github.com/omni360/three.js.sourcecode