Initial project import

node_modules/troika-three-utils/src/BezierMesh.js

@@ -0,0 +1,112 @@
+import { CylinderGeometry, DoubleSide, Mesh, MeshStandardMaterial, Vector2, Vector3 } from 'three'
+import { createBezierMeshMaterial } from './BezierMeshMaterial.js'
+
+let geometry = null
+
+const defaultBaseMaterial = /*#__PURE__*/new MeshStandardMaterial({color: 0xffffff, side: DoubleSide})
+
+
+/**
+ * A ThreeJS `Mesh` that bends a tube shape along a 3D cubic bezier path. The bending is done
+ * by deforming a straight cylindrical geometry in the vertex shader based on a set of four
+ * control point uniforms. It patches the necessary GLSL into the mesh's assigned `material`
+ * automatically.
+ *
+ * The cubiz bezier path is determined by its four `Vector3` properties:
+ * - `pointA`
+ * - `controlA`
+ * - `controlB`
+ * - `pointB`
+ *
+ * The tube's radius is controlled by its `radius` property, which defaults to `0.01`.
+ *
+ * You can also give the tube a dashed appearance with two properties:
+ *
+ * - `dashArray` - an array of two numbers, defining the length of "on" and "off" parts of
+ *   the dash. Each is a 0-1 ratio of the entire path's length. (Actually this is the `t` length
+ *   used as input to the cubic bezier function, not its visible length.)
+ * - `dashOffset` - offset of where the dash starts. You can animate this to make the dashes move.
+ *
+ * Note that the dashes will appear like a hollow tube, not solid. This will be more apparent on
+ * thicker tubes.
+ *
+ * TODO: proper geometry bounding sphere and raycasting
+ * TODO: allow control of the geometry's segment counts
+ */
+class BezierMesh extends Mesh {
+  static getGeometry() {
+    return geometry || (geometry =
+      new CylinderGeometry(1, 1, 1, 6, 64).translate(0, 0.5, 0)
+    )
+  }
+
+  constructor() {
+    super(
+      BezierMesh.getGeometry(),
+      defaultBaseMaterial
+    )
+
+    this.pointA = new Vector3()
+    this.controlA = new Vector3()
+    this.controlB = new Vector3()
+    this.pointB = new Vector3()
+    this.radius = 0.01
+    this.dashArray = new Vector2()
+    this.dashOffset = 0
+
+    // TODO - disabling frustum culling until I figure out how to customize the
+    //  geometry's bounding sphere that gets used
+    this.frustumCulled = false
+  }
+
+  // Handler for automatically wrapping the base material with our upgrades. We do the wrapping
+  // lazily on _read_ rather than write to avoid unnecessary wrapping on transient values.
+  get material() {
+    let derivedMaterial = this._derivedMaterial
+    const baseMaterial = this._baseMaterial || this._defaultMaterial || (this._defaultMaterial = defaultBaseMaterial.clone())
+    if (!derivedMaterial || derivedMaterial.baseMaterial !== baseMaterial) {
+      derivedMaterial = this._derivedMaterial = createBezierMeshMaterial(baseMaterial)
+      // dispose the derived material when its base material is disposed:
+      baseMaterial.addEventListener('dispose', function onDispose() {
+        baseMaterial.removeEventListener('dispose', onDispose)
+        derivedMaterial.dispose()
+      })
+    }
+    return derivedMaterial
+  }
+  set material(baseMaterial) {
+    this._baseMaterial = baseMaterial
+  }
+
+  // Create and update material for shadows upon request:
+  get customDepthMaterial() {
+    return this.material.getDepthMaterial()
+  }
+  set customDepthMaterial(m) {
+    // future: let the user override with their own?
+  }
+  get customDistanceMaterial() {
+    return this.material.getDistanceMaterial()
+  }
+  set customDistanceMaterial(m) {
+    // future: let the user override with their own?
+  }
+
+  onBeforeRender() {
+    const {uniforms} = this.material
+    const {pointA, controlA, controlB, pointB, radius, dashArray, dashOffset} = this
+    uniforms.pointA.value.copy(pointA)
+    uniforms.controlA.value.copy(controlA)
+    uniforms.controlB.value.copy(controlB)
+    uniforms.pointB.value.copy(pointB)
+    uniforms.radius.value = radius
+    uniforms.dashing.value.set(dashArray.x, dashArray.y, dashOffset || 0)
+  }
+
+  raycast(/*raycaster, intersects*/) {
+    // TODO - just fail for now
+  }
+}
+
+
+export { BezierMesh }