awayjs-display/lib/pick/JSPickingCollider.ts

AwayJS displaylist classes

import Vector3D							from "awayjs-core/lib/geom/Vector3D";
import Point							from "awayjs-core/lib/geom/Point";
import LineElements						from "../graphics/LineElements";
import TriangleElements					from "../graphics/TriangleElements";
import Billboard						from "../display/Billboard";
import PickingCollision					from "../pick/PickingCollision";
import IPickingCollider					from "../pick/IPickingCollider";
import MaterialBase						from "../materials/MaterialBase";


/**
 * Pure JS picking collider for display objects. Used with the <code>RaycastPicker</code> picking object.
 *
 * @see away.base.DisplayObject#pickingCollider
 * @see away.pick.RaycastPicker
 *
 * @class away.pick.JSPickingCollider
 */
class JSPickingCollider implements IPickingCollider
{
	private _findClosestCollision:boolean;

	/**
	 * Creates a new <code>JSPickingCollider</code> object.
	 *
	 * @param findClosestCollision Determines whether the picking collider searches for the closest collision along the ray. Defaults to false.
	 */
	constructor(findClosestCollision:boolean = false)
	{
		this._findClosestCollision = findClosestCollision;
	}


	/**
	 * Tests a <code>Billboard</code> object for a collision with the picking ray.
	 *
	 * @param billboard The billboard instance to be tested.
	 * @param pickingCollision The collision object used to store the collision results
	 * @param findClosest
	 */
	public testBillboardCollision(billboard:Billboard, material:MaterialBase, pickingCollision:PickingCollision)
	{
		pickingCollision.renderable = null;

		//if (this._testGraphicCollision(<RenderableBase> this._renderablePool.getItem(billboard), pickingCollision, shortestCollisionDistance)) {
		//	shortestCollisionDistance = pickingCollision.rayEntryDistance;
		//
		//	pickingCollision.renderable = billboard;
		//
		//	return true;
		//}

		return false;
	}

	/**
	 * Tests a <code>TriangleElements</code> object for a collision with the picking ray.
	 *
	 * @param triangleElements
	 * @param material
	 * @param pickingCollision
	 * @returns {boolean}
	 */
	public testTriangleCollision(triangleElements:TriangleElements, material:MaterialBase, pickingCollision:PickingCollision):boolean
	{
		var rayPosition:Vector3D = pickingCollision.rayPosition;
		var rayDirection:Vector3D = pickingCollision.rayDirection;
		var t:number;
		var i0:number, i1:number, i2:number;
		var rx:number, ry:number, rz:number;
		var nx:number, ny:number, nz:number;
		var cx:number, cy:number, cz:number;
		var coeff:number, u:number, v:number, w:number;
		var p0x:number, p0y:number, p0z:number;
		var p1x:number, p1y:number, p1z:number;
		var p2x:number, p2y:number, p2z:number;
		var s0x:number, s0y:number, s0z:number;
		var s1x:number, s1y:number, s1z:number;
		var nl:number, nDotV:number, D:number, disToPlane:number;
		var Q1Q2:number, Q1Q1:number, Q2Q2:number, RQ1:number, RQ2:number;
		var collisionTriangleIndex:number = -1;
		var bothSides:boolean = material.bothSides;

		var positions:ArrayBufferView = triangleElements.positions.get(triangleElements.numVertices);
		var posDim:number = triangleElements.positions.dimensions;

		var indices:Uint16Array;
		var count:number;
		if (triangleElements.indices) {
			indices = triangleElements.indices.get(triangleElements.numElements);
			count = indices.length;
		} else {
			count = triangleElements.numVertices;
		}

		for (var index:number = 0; index < count; index+=3) { // sweep all triangles
			// evaluate triangle indices
			if (indices) {
				i0 = indices[index]*posDim;
				i1 = indices[index + 1]*posDim;
				i2 = indices[index + 2]*posDim;
			} else {
				i0 = index*posDim;
				i1 = (index + 1)*posDim;
				i2 = (index + 2)*posDim;
			}


			// evaluate triangle positions
			p0x = positions[i0];
			p1x = positions[i1];
			p2x = positions[i2];
			s0x = p1x - p0x; // s0 = p1 - p0
			s1x = p2x - p0x; // s1 = p2 - p0

			p0y = positions[i0 + 1];
			p1y = positions[i1 + 1];
			p2y = positions[i2 + 1];
			s0y = p1y - p0y;
			s1y = p2y - p0y;

			if (posDim == 3) {
				p0z = positions[i0 + 2];
				p1z = positions[i1 + 2];
				p2z = positions[i2 + 2];
				s0z = p1z - p0z;
				s1z = p2z - p0z;

				// evaluate sides and triangle normal
				nx = s0y*s1z - s0z*s1y; // n = s0 x s1
				ny = s0z*s1x - s0x*s1z;
				nz = s0x*s1y - s0y*s1x;
				nl = 1/Math.sqrt(nx*nx + ny*ny + nz*nz); // normalize n
				nx *= nl;
				ny *= nl;
				nz *= nl;
			} else { //2d hittest
				nx = 0;
				ny = 0;
				nz = 1;
			}

			// -- plane intersection test --
			nDotV = nx*rayDirection.x + ny* +rayDirection.y + nz*rayDirection.z; // rayDirection . normal
			if (( !bothSides && nDotV < 0.0 ) || ( bothSides && nDotV != 0.0 )) { // an intersection must exist
				// find collision t
				D = -( nx*p0x + ny*p0y + nz*p0z );
				disToPlane = -( nx*rayPosition.x + ny*rayPosition.y + nz*rayPosition.z + D );
				t = disToPlane/nDotV;
				// find collision point
				cx = rayPosition.x + t*rayDirection.x;
				cy = rayPosition.y + t*rayDirection.y;
				cz = rayPosition.z + t*rayDirection.z;
				// collision point inside triangle? ( using barycentric coordinates )
				Q1Q2 = s0x*s1x + s0y*s1y + s0z*s1z;
				Q1Q1 = s0x*s0x + s0y*s0y + s0z*s0z;
				Q2Q2 = s1x*s1x + s1y*s1y + s1z*s1z;
				rx = cx - p0x;
				ry = cy - p0y;
				rz = cz - p0z;
				RQ1 = rx*s0x + ry*s0y + rz*s0z;
				RQ2 = rx*s1x + ry*s1y + rz*s1z;
				coeff = 1/(Q1Q1*Q2Q2 - Q1Q2*Q1Q2);
				v = coeff*(Q2Q2*RQ1 - Q1Q2*RQ2);
				w = coeff*(-Q1Q2*RQ1 + Q1Q1*RQ2);
				if (v < 0)
					continue;
				if (w < 0)
					continue;
				u = 1 - v - w;
				if (!( u < 0 ) && t > 0 && t < pickingCollision.rayEntryDistance) { // all tests passed
					collisionTriangleIndex = index/3;
					pickingCollision.rayEntryDistance = t;
					pickingCollision.position = new Vector3D(cx, cy, cz);
					pickingCollision.normal = new Vector3D(nx, ny, nz);
					if (triangleElements.uvs) { //uv calculations
						var uvs:ArrayBufferView = triangleElements.uvs.get(triangleElements.numVertices);
						var uvDim:number = triangleElements.uvs.dimensions;

						var uIndex:number = indices[index]*uvDim;
						var uv0:Vector3D = new Vector3D(uvs[uIndex], uvs[uIndex + 1]);
						uIndex = indices[index + 1]*uvDim;
						var uv1:Vector3D = new Vector3D(uvs[uIndex], uvs[uIndex + 1]);
						uIndex = indices[index + 2]*uvDim;
						var uv2:Vector3D = new Vector3D(uvs[uIndex], uvs[uIndex + 1]);
						pickingCollision.uv = new Point(u*uv0.x + v*uv1.x + w*uv2.x, u*uv0.y + v*uv1.y + w*uv2.y);
					}
					pickingCollision.elementIndex = collisionTriangleIndex;

					// if not looking for best hit, first found will do...
					if (!this._findClosestCollision)
						return true;
				}
			}
		}


		if (collisionTriangleIndex >= 0)
			return true;

		return false;
	}
	//
	///**
	// * Tests a <code>CurveElements</code> object for a collision with the picking ray.
	// *
	// * @param triangleElements
	// * @param material
	// * @param pickingCollision
	// * @returns {boolean}
	// */
	//public testCurveCollision(curveElements:CurveElements, material:MaterialBase, pickingCollision:PickingCollision, shortestCollisionDistance:number):boolean
	//{
	//	var rayPosition:Vector3D = pickingCollision.localRayPosition;
	//	var rayDirection:Vector3D = pickingCollision.localRayDirection;
	//
	//	//project ray onto x/y plane to generate useful test points from mouse coordinates
	//	//this will only work while all points lie on the x/y plane
	//	var plane:Vector3D = new Vector3D(0,0,-1,0);
	//
	//	var result:Vector3D = new Vector3D();
	//	var distance:number = plane.x * rayPosition.x + plane.y * rayPosition.y + plane.z * rayPosition.z + plane.w;//distance(position);
	//	result.x = rayPosition.x - ( plane.x*distance);
	//	result.y = rayPosition.y - ( plane.y*distance);
	//	result.z = rayPosition.z - ( plane.z*distance);
	//	var normal:Vector3D = new Vector3D(plane.x,plane.y,plane.z);
	//	var t:number = -(rayPosition.dotProduct(normal))/(rayDirection.dotProduct(normal));
	//	rayDirection.scaleBy(t);
	//	var p:Vector3D = rayPosition.add(rayDirection);
	//
	//	var indices:Uint16Array = curveElements.indices.get(curveElements.numElements);
	//	var collisionCurveIndex:number = -1;
	//	var bothSides:boolean = material.bothSides;
	//
	//
	//	var positions:Float32Array = curveElements.positions.get(curveElements.numVertices);
	//	var posDim:number = curveElements.positions.dimensions;
	//	var curves:Float32Array = curveElements.curves.get(curveElements.numVertices);
	//	var curveDim:number = curveElements.curves.dimensions;
	//	var uvs:ArrayBufferView = curveElements.uvs.get(curveElements.numVertices);
	//	var uvDim:number = curveElements.uvs.dimensions;
	//	var numIndices:number = indices.length;
	//
	//
	//	for(var index:number = 0; index < numIndices; index+=3)
	//	{
	//		var id0:number = indices[index];
	//		var id1:number = indices[index + 1] * posDim;
	//		var id2:number = indices[index + 2] * posDim;
	//
	//		var ax:number = positions[id0 * posDim];
	//		var ay:number = positions[id0 * posDim + 1];
	//		var bx:number = positions[id1];
	//		var by:number = positions[id1 + 1];
	//		var cx:number = positions[id2];
	//		var cy:number = positions[id2 + 1];
	//
	//		var curvex:number = curves[id0 * curveDim];
	//		var az:number = positions[id0 * posDim + 2];
	//
	//		//console.log(ax, ay, bx, by, cx, cy);
	//
	//		//from a to p
	//		var dx:number = ax - p.x;
	//		var dy:number = ay - p.y;
	//
	//		//edge normal (a-b)
	//		var nx:number = by - ay;
	//		var ny:number = -(bx - ax);
	//
	//		//console.log(ax,ay,bx,by,cx,cy);
	//
	//		var dot:number = (dx * nx) + (dy * ny);
	//		//console.log("dot a",dot);
	//		if (dot > 0)
	//			continue;
	//
	//		dx = bx - p.x;
	//		dy = by - p.y;
	//		nx = cy - by;
	//		ny = -(cx - bx);
	//
	//		dot = (dx * nx) + (dy * ny);
	//		//console.log("dot b",dot);
	//		if (dot > 0)
	//			continue;
	//
	//		dx = cx - p.x;
	//		dy = cy - p.y;
	//		nx = ay - cy;
	//		ny = -(ax - cx);
	//
	//		dot = (dx * nx) + (dy * ny);
	//		//console.log("dot c",dot);
	//		if (dot > 0)
	//			continue;
	//
	//		//check if not solid
	//		if (curvex != 2) {
	//
	//			var v0x:number = bx - ax;
	//			var v0y:number = by - ay;
	//			var v1x:number = cx - ax;
	//			var v1y:number = cy - ay;
	//			var v2x:number = p.x - ax;
	//			var v2y:number = p.y - ay;
	//
	//			var den:number = v0x * v1y - v1x * v0y;
	//			var v:number = (v2x * v1y - v1x * v2y) / den;
	//			var w:number = (v0x * v2y - v2x * v0y) / den;
	//			var u:number = 1 - v - w;
	//
	//			var uu:number = 0.5 * v + w;// (0 * u) + (0.5 * v) + (1 * w);// (lerp(0, 0.5, v) + lerp(0.5, 1, w) + lerp(1, 0, u)) / 1.5;
	//			var vv:number = w;// (0 * u) + (0 * v) + (1 * w);// (lerp(0, 1, w) + lerp(1, 0, u)) / 1;
	//
	//			var d:number = uu * uu - vv;
	//
	//			if ((d > 0 && az == -1) || (d < 0 && az == 1))
	//				continue;
	//		}
	//		//TODO optimize away this pointless check as the distance is always the same
	//		//also this stuff should only be calculated right before the return and not for each hit
	//		if (distance < shortestCollisionDistance) {
	//			shortestCollisionDistance = distance;
	//			collisionCurveIndex = index/3;
	//			pickingCollision.rayEntryDistance = distance;
	//			pickingCollision.localPosition = p;
	//			pickingCollision.localNormal = new Vector3D(0, 0, 1);
	//			pickingCollision.uv = this._getCollisionUV(indices, uvs, index, v, w, u, uvDim);
	//			pickingCollision.index = index;
	//			//						pickingCollision.elementIndex = this.pGetSpriteGraphicIndex(renderable);
	//
	//			// if not looking for best hit, first found will do...
	//			if (!this._findClosestCollision)
	//				return true;
	//		}
	//	}
	//
	//	if (collisionCurveIndex >= 0)
	//		return true;
	//
	//	return false;
	//}

	/**
	 * Tests a <code>LineElements</code> object for a collision with the picking ray.
	 *
	 * @param triangleElements
	 * @param material
	 * @param pickingCollision
	 * @returns {boolean}
	 */
	public testLineCollision(lineElements:LineElements, material:MaterialBase, pickingCollision:PickingCollision):boolean
	{
		return false;
	}
}

export default JSPickingCollider;