simple subdivision

src/engine/components/planet/index.js

@@ -2,6 +2,8 @@ import { Mesh } from '../../mesh'
 import { mat4 } from 'gl-matrix'
 import { subv3, mulv3, addv3, normalv3, crossv3 } from '../../utility'
 
+const lodMax = 8
+
 class CubeFace {
   constructor (parent, level, pos, normal, resolution, radius, generator) {
     this.parent = parent
@@ -14,6 +16,7 @@ class CubeFace {
     this.level = level
 
     this.generated = false
+    this.generator = generator
 
     // Calculate left (x) and forward (z) vectors from the normal (y)
     this.left = [normal[1], normal[2], normal[0]]
@@ -25,6 +28,10 @@ class CubeFace {
     this.position = subv3(this.position, mulv3(this.left, this.radius / 2))
     this.position = subv3(this.position, mulv3(this.forward, this.radius / 2))
 
+    if (this.parent) {
+      this.transform = this.parent.transform
+    }
+
     this.generate()
   }
 
@@ -84,7 +91,54 @@ class CubeFace {
     this.generated = true
   }
 
+  dispose () {
+    this.mesh = null
+    this.generated = false
+  }
+
+  merge () {
+    if (!this.children.length) return
+
+    for (let i in this.children) {
+      let ch = this.children[i]
+
+      ch.merge()
+      ch.dispose()
+    }
+
+    this.children = []
+  }
+
+  subdivide () {
+    if (this.level === lodMax) return
+
+    let subPos = this.position
+    subPos = addv3(subPos, mulv3(this.left, this.radius / 2))
+    subPos = addv3(subPos, mulv3(this.forward, this.radius / 2))
+
+    let stepLeft = mulv3(this.left, this.radius / 4)
+    let stepForward = mulv3(this.forward, this.radius / 4)
+    let hs = this.radius / 2
+    let lv = this.level + 1
+
+    this.children = [
+      new CubeFace(this, lv, addv3(subv3(subPos, stepLeft), stepForward), this.normal, this.resolution, hs, this.generator),
+      new CubeFace(this, lv, addv3(addv3(subPos, stepLeft), stepForward), this.normal, this.resolution, hs, this.generator),
+      new CubeFace(this, lv, subv3(subv3(subPos, stepLeft), stepForward), this.normal, this.resolution, hs, this.generator),
+      new CubeFace(this, lv, subv3(addv3(subPos, stepLeft), stepForward), this.normal, this.resolution, hs, this.generator)
+    ]
+
+    this.dispose()
+  }
+
   draw (gl, shader) {
+    if (!this.mesh) {
+      for (let i in this.children) {
+        this.children[i].draw(gl, shader)
+      }
+      return
+    }
+
     // Set model transform matrix uniform
     const transformLocation = shader.getUniformLocation(gl, 'uModelMatrix')
     gl.uniformMatrix4fv(transformLocation, false, this.transform)
@@ -116,9 +170,8 @@ class CubePlanet {
       new CubeFace(this, 0, [0, -hs, 0], [0, -1, 0], resolution, radius, generator) // bottom
     ]
 
-    for (let i in this.faces) {
-      this.faces[i].transform = this.transform
-    }
+    this.faces[0].subdivide()
+    this.faces[0].children[0].subdivide()
   }
 
   draw (gl, shader) {

src/index.js

@@ -34,7 +34,7 @@ async function pipeline () {
   terrain.setMaterial(material)
 
   // Create and initialize the camera
-  let cam = new Camera([-60.0, 1.0, 0.0])
+  let cam = new Camera([-200.0, 1.0, 0.0])
   cam.updateProjection(game.gl)
 
   // Planet test