@babylonjs/core/Meshes/Builders/discBuilder.js

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import { Mesh } from "../mesh.js";
import { VertexData } from "../mesh.vertexData.js";
import { useOpenGLOrientationForUV } from "../../Compat/compatibilityOptions.js";
/**
 * Creates the VertexData of the Disc or regular Polygon
 * @param options an object used to set the following optional parameters for the disc, required but can be empty
 * * radius the radius of the disc, optional default 0.5
 * * tessellation the number of polygon sides, optional, default 64
 * * arc a number from 0 to 1, to create an unclosed polygon based on the fraction of the circumference given by the arc value, optional, default 1
 * * sideOrientation optional and takes the values : Mesh.FRONTSIDE (default), Mesh.BACKSIDE or Mesh.DOUBLESIDE
 * * frontUvs only usable when you create a double-sided mesh, used to choose what parts of the texture image to crop and apply on the front side, optional, default vector4 (0, 0, 1, 1)
 * * backUVs only usable when you create a double-sided mesh, used to choose what parts of the texture image to crop and apply on the back side, optional, default vector4 (0, 0, 1, 1)
 * @returns the VertexData of the box
 */
// eslint-disable-next-line @typescript-eslint/naming-convention
export function CreateDiscVertexData(options) {
    const positions = [];
    const indices = [];
    const normals = [];
    const uvs = [];
    const radius = options.radius || 0.5;
    const tessellation = options.tessellation || 64;
    const arc = options.arc && (options.arc <= 0 || options.arc > 1) ? 1.0 : options.arc || 1.0;
    const sideOrientation = options.sideOrientation === 0 ? 0 : options.sideOrientation || VertexData.DEFAULTSIDE;
    // positions and uvs
    positions.push(0, 0, 0); // disc center first
    uvs.push(0.5, 0.5);
    const theta = Math.PI * 2 * arc;
    const step = arc === 1 ? theta / tessellation : theta / (tessellation - 1);
    let a = 0;
    for (let t = 0; t < tessellation; t++) {
        const x = Math.cos(a);
        const y = Math.sin(a);
        const u = (x + 1) / 2;
        const v = (1 - y) / 2;
        positions.push(radius * x, radius * y, 0);
        uvs.push(u, useOpenGLOrientationForUV ? 1 - v : v);
        a += step;
    }
    if (arc === 1) {
        positions.push(positions[3], positions[4], positions[5]); // close the circle
        uvs.push(uvs[2], useOpenGLOrientationForUV ? 1 - uvs[3] : uvs[3]);
    }
    //indices
    const vertexNb = positions.length / 3;
    for (let i = 1; i < vertexNb - 1; i++) {
        indices.push(i + 1, 0, i);
    }
    // result
    VertexData.ComputeNormals(positions, indices, normals);
    VertexData._ComputeSides(sideOrientation, positions, indices, normals, uvs, options.frontUVs, options.backUVs);
    const vertexData = new VertexData();
    vertexData.indices = indices;
    vertexData.positions = positions;
    vertexData.normals = normals;
    vertexData.uvs = uvs;
    return vertexData;
}
/**
 * Creates a plane polygonal mesh.  By default, this is a disc
 * * The parameter `radius` sets the radius size (float) of the polygon (default 0.5)
 * * The parameter `tessellation` sets the number of polygon sides (positive integer, default 64). So a tessellation valued to 3 will build a triangle, to 4 a square, etc
 * * You can create an unclosed polygon with the parameter `arc` (positive float, default 1), valued between 0 and 1, what is the ratio of the circumference : 2 x PI x ratio
 * * You can also set the mesh side orientation with the values : BABYLON.Mesh.FRONTSIDE (default), BABYLON.Mesh.BACKSIDE or BABYLON.Mesh.DOUBLESIDE
 * * If you create a double-sided mesh, you can choose what parts of the texture image to crop and stick respectively on the front and the back sides with the parameters `frontUVs` and `backUVs` (Vector4). Detail here : https://doc.babylonjs.com/features/featuresDeepDive/mesh/creation/set#side-orientation
 * * The mesh can be set to updatable with the boolean parameter `updatable` (default false) if its internal geometry is supposed to change once created
 * @param name defines the name of the mesh
 * @param options defines the options used to create the mesh
 * @param scene defines the hosting scene
 * @returns the plane polygonal mesh
 * @see https://doc.babylonjs.com/features/featuresDeepDive/mesh/creation/set#disc-or-regular-polygon
 */
export function CreateDisc(name, options = {}, scene = null) {
    const disc = new Mesh(name, scene);
    options.sideOrientation = Mesh._GetDefaultSideOrientation(options.sideOrientation);
    disc._originalBuilderSideOrientation = options.sideOrientation;
    const vertexData = CreateDiscVertexData(options);
    vertexData.applyToMesh(disc, options.updatable);
    return disc;
}
/**
 * Class containing static functions to help procedurally build meshes
 * @deprecated please use CreateDisc directly
 */
export const DiscBuilder = {
    // eslint-disable-next-line @typescript-eslint/naming-convention
    CreateDisc,
};
VertexData.CreateDisc = CreateDiscVertexData;
Mesh.CreateDisc = (name, radius, tessellation, scene = null, updatable, sideOrientation) => {
    const options = {
        radius,
        tessellation,
        sideOrientation,
        updatable,
    };
    return CreateDisc(name, options, scene);
};
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