221 lines
6.2 KiB
JavaScript
221 lines
6.2 KiB
JavaScript
import { Mesh } from '../../mesh'
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import { BoundingBox } from '../../mesh/aabb'
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import { mat4, vec3 } from 'gl-matrix'
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import { subv3, mulv3, addv3, divv3, normalv3, crossv3 } from '../../utility'
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import Screen from '../../screen'
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const lodMax = 8
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class PlanetGenerator {
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constructor (resolution, radius, noise) {
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this.resolution = resolution
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this.radius = radius
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this.noise = noise
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}
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}
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class CubeFace {
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constructor (parent, level, pos, normal, generator) {
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this.parent = parent
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this.children = []
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this.normal = normal
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this.level = level
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this.generated = false
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this.generator = generator
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// Calculate left (x) and forward (z) vectors from the normal (y)
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this.left = [normal[1], normal[2], normal[0]]
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this.forward = crossv3(normal, this.left)
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this.position = pos
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// Center the face
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if (level === 0) {
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this.position = subv3(this.position, mulv3(this.left, generator.radius / 2))
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this.position = subv3(this.position, mulv3(this.forward, generator.radius / 2))
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}
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this.generate()
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}
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generate () {
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if (this.generated) return
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let VERTICES = this.generator.resolution
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let count = VERTICES * VERTICES
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let vertices = new Array(count * 3)
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let normals = new Array(count * 3)
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let textureCoords = new Array(count * 2)
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let indices = new Array(6 * (VERTICES - 1) * (VERTICES - 1))
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let radius = this.generator.radius
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let divisionLevel = Math.pow(2, this.level)
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for (let i = 0, vertexPointer = 0; i < VERTICES; i++) {
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for (let j = 0; j < VERTICES; j++, vertexPointer++) {
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// Vertex index (0 - 1)
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let iindex = i / (VERTICES - 1)
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let jindex = j / (VERTICES - 1)
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// From the left and forward vectors, we can calculate an oriented vertex
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let iv = divv3(mulv3(mulv3(this.left, iindex), radius), divisionLevel)
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let jv = divv3(mulv3(mulv3(this.forward, jindex), radius), divisionLevel)
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// Add the scaled left and forward to the centered origin
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let vertex = addv3(this.position, addv3(iv, jv))
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// Normalize and multiply by radius to create a spherical mesh
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let normal = normalv3(vertex)
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let pos = mulv3(normal, (radius))
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vertices[vertexPointer * 3] = pos[0]
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vertices[vertexPointer * 3 + 1] = pos[1]
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vertices[vertexPointer * 3 + 2] = pos[2]
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normals[vertexPointer * 3] = normal[0]
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normals[vertexPointer * 3 + 1] = normal[1]
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normals[vertexPointer * 3 + 2] = normal[2]
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textureCoords[vertexPointer * 2] = j * (1 / VERTICES)
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textureCoords[vertexPointer * 2 + 1] = i * (1 / VERTICES)
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if (i === VERTICES / 2 && j === VERTICES / 2) {
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this.center = pos
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}
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}
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}
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for (let gz = 0, pointer = 0; gz < VERTICES - 1; gz++) {
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for (let gx = 0; gx < VERTICES - 1; gx++) {
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let topLeft = (gz * VERTICES) + gx
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let topRight = topLeft + 1
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let bottomLeft = ((gz + 1) * VERTICES) + gx
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let bottomRight = bottomLeft + 1
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indices[pointer++] = topLeft
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indices[pointer++] = bottomLeft
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indices[pointer++] = topRight
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indices[pointer++] = topRight
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indices[pointer++] = bottomLeft
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indices[pointer++] = bottomRight
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}
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}
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this.mesh = Mesh.construct(Screen.gl, vertices, indices, textureCoords, normals)
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this.generated = true
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}
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dispose () {
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this.generated = false
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if (this.mesh) {
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// this.mesh.dispose(Screen.gl)
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this.mesh = null
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}
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}
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merge () {
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if (!this.children.length) return
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for (let i in this.children) {
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let ch = this.children[i]
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ch.merge()
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ch.dispose()
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}
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this.children = []
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this.generate()
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}
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subdivide () {
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if (this.level === lodMax) return
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let lv = this.level + 1
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let stepLeft = mulv3(this.left, this.generator.radius / Math.pow(2, lv))
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let stepForward = mulv3(this.forward, this.generator.radius / Math.pow(2, lv))
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this.children = [
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new CubeFace(this, lv, this.position, this.normal, this.generator),
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new CubeFace(this, lv, addv3(this.position, stepForward), this.normal, this.generator),
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new CubeFace(this, lv, addv3(this.position, stepLeft), this.normal, this.generator),
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new CubeFace(this, lv, addv3(this.position, addv3(stepLeft, stepForward)), this.normal, this.generator)
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]
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this.dispose()
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}
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draw (gl, shader) {
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if (!this.mesh) {
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for (let i in this.children) {
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this.children[i].draw(gl, shader)
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}
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return
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}
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this.mesh.prepare(gl, shader)
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this.mesh.draw(gl, shader)
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}
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update (camera, dt) {
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if (!this.center) return
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let camToOrigin = vec3.distance(camera.pos, this.center)
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let divisionLevel = Math.pow(2, this.level)
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let splitDistance = this.generator.radius / divisionLevel
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if (camToOrigin < splitDistance * 1.5 && this.children.length === 0) {
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this.subdivide()
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return
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} else if (camToOrigin > splitDistance * 2 && this.children.length > 0) {
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this.merge()
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return
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}
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if (this.children.length > 0) {
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for (let i in this.children) {
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this.children[i].update(camera, dt)
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}
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}
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}
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}
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class CubePlanet {
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constructor (origin, generator) {
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this.origin = origin
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this.generator = generator
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this.transform = mat4.create()
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mat4.fromTranslation(this.transform, origin)
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let hs = generator.radius / 2
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this.faces = [
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new CubeFace(this, 0, [0, 0, -hs], [0, 0, -1], generator), // front
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new CubeFace(this, 0, [0, 0, hs], [0, 0, 1], generator), // back
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new CubeFace(this, 0, [-hs, 0, 0], [-1, 0, 0], generator), // left
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new CubeFace(this, 0, [hs, 0, 0], [1, 0, 0], generator), // right
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new CubeFace(this, 0, [0, hs, 0], [0, 1, 0], generator), // top
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new CubeFace(this, 0, [0, -hs, 0], [0, -1, 0], generator) // bottom
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]
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}
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update (camera, dt) {
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for (let i in this.faces) {
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this.faces[i].update(camera, dt)
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}
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}
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draw (gl, shader) {
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// Set model transform matrix uniform
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const transformLocation = shader.getUniformLocation(gl, 'uModelMatrix')
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gl.uniformMatrix4fv(transformLocation, false, this.transform)
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for (let i in this.faces) {
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this.faces[i].draw(gl, shader)
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}
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}
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}
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export { CubePlanet, CubeFace, PlanetGenerator }
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