module.exports = Ray;
var Vec3 = require('../math/Vec3');
var Quaternion = require('../math/Quaternion');
var Transform = require('../math/Transform');
var ConvexPolyhedron = require('../shapes/ConvexPolyhedron');
var Box = require('../shapes/Box');
var RaycastResult = require('../collision/RaycastResult');
var Shape = require('../shapes/Shape');
var AABB = require('../collision/AABB');
/**
* A line in 3D space that intersects bodies and return points.
* @class Ray
* @constructor
* @param {Vec3} from
* @param {Vec3} to
*/
function Ray(from, to){
/**
* @property {Vec3} from
*/
this.from = from ? from.clone() : new Vec3();
/**
* @property {Vec3} to
*/
this.to = to ? to.clone() : new Vec3();
this._direction = new Vec3();
/**
* The precision of the ray. Used when checking parallelity etc.
* @property {Number} precision
*/
this.precision = 0.0001;
}
Ray.prototype.constructor = Ray;
var v1 = new Vec3(),
v2 = new Vec3();
/*
* As per "Barycentric Technique" as named here http://www.blackpawn.com/texts/pointinpoly/default.html But without the division
*/
function pointInTriangle(p, a, b, c) {
c.vsub(a,v0);
b.vsub(a,v1);
p.vsub(a,v2);
var dot00 = v0.dot( v0 );
var dot01 = v0.dot( v1 );
var dot02 = v0.dot( v2 );
var dot11 = v1.dot( v1 );
var dot12 = v1.dot( v2 );
var u,v;
return ( (u = dot11 * dot02 - dot01 * dot12) >= 0 ) &&
( (v = dot00 * dot12 - dot01 * dot02) >= 0 ) &&
( u + v < ( dot00 * dot11 - dot01 * dot01 ) );
}
/**
* Shoot a ray at a body, get back information about the hit.
* @method intersectBody
* @param {Body} body
* @return {Array} An array of results. The result objects has properties: distance (float), point (Vec3) and body (Body).
*/
Ray.prototype.intersectBody = function (body, result, direction) {
if(!direction){
this._updateDirection();
direction = this._direction;
}
var xi = new Vec3();
var qi = new Quaternion();
for (var i = 0; i < body.shapes.length; i++) {
body.quaternion.mult(body.shapeOrientations[i], qi);
body.quaternion.vmult(body.shapeOffsets[i], xi);
xi.vadd(body.position, xi);
return this.intersectShape(
body.shapes[i],
qi,
xi,
body,
direction,
result
);
}
};
/**
* @method intersectBodies
* @param {Array} bodies An array of Body objects.
* @return {Array} See intersectBody
*/
Ray.prototype.intersectBodies = function (bodies, result) {
this._updateDirection();
var direction = this._direction;
if(result instanceof RaycastResult){
result.reset();
}
for ( var i = 0, l = bodies.length; i < l; i ++ ) {
this.intersectBody(bodies[i], result, direction);
}
};
Ray.prototype._updateDirection = function(){
this.to.vsub(this.from, this._direction);
this._direction.normalize();
};
/**
* @method intersectShape
* @param {Shape} shape
* @param {Quaternion} quat
* @param {Vec3} position
* @param {Body} body
* @return {Array} See intersectBody()
*/
Ray.prototype.intersectShape = function(shape, quat, position, body, direction, result){
var from = this.from;
// Checking boundingSphere
var distance = distanceFromIntersection(from, direction, position);
if ( distance > shape.boundingSphereRadius ) {
return result;
}
this[shape.type](shape, quat, position, body, direction, result);
return result;
};
var vector = new Vec3();
var normal = new Vec3();
var intersectPoint = new Vec3();
var a = new Vec3();
var b = new Vec3();
var c = new Vec3();
var d = new Vec3();
var tmpRaycastResult = new RaycastResult();
Ray.prototype.intersectBox = function(shape, quat, position, body, direction, result){
return this.intersectConvex(shape.convexPolyhedronRepresentation, quat, position, body, direction, result);
};
Ray.prototype[Shape.types.BOX] = Ray.prototype.intersectBox;
Ray.prototype.intersectPlane = function(shape, quat, position, body, direction, result){
var from = this.from;
var to = this.to;
// Get plane normal
var worldNormal = new Vec3(0, 0, 1);
quat.vmult(worldNormal, worldNormal);
var len = new Vec3();
from.vsub(position, len);
var planeToFrom = len.dot(worldNormal);
to.vsub(position, len);
var planeToTo = len.dot(worldNormal);
if(planeToFrom * planeToTo > 0){
// "from" and "to" are on the same side of the plane... bail out
return result;
}
if(from.distanceTo(to) < planeToFrom){
return result;
}
var n_dot_dir = worldNormal.dot(direction);
if (Math.abs(n_dot_dir) < this.precision) {
// No intersection
return result;
}
var planePointToFrom = new Vec3();
var dir_scaled_with_t = new Vec3();
var hitPointWorld = new Vec3();
from.vsub(position, planePointToFrom);
var t = -worldNormal.dot(planePointToFrom) / n_dot_dir;
direction.scale(t, dir_scaled_with_t);
from.vadd(dir_scaled_with_t, hitPointWorld);
if(this.reportIntersection(worldNormal, hitPointWorld, shape, body, result)){
return result;
}
return result;
};
Ray.prototype[Shape.types.PLANE] = Ray.prototype.intersectPlane;
Ray.prototype.getAABB = function(result){
var to = this.to;
var from = this.from;
result.lowerBound.x = Math.min(to.x, from.x);
result.lowerBound.y = Math.min(to.y, from.y);
result.upperBound.x = Math.max(to.x, from.x);
result.upperBound.y = Math.max(to.y, from.y);
};
var intersectConvexOptions = {
faceList: [0]
};
Ray.prototype.intersectHeightfield = function(shape, quat, position, body, direction, result){
var data = shape.data,
w = shape.elementSize,
worldPillarOffset = new Vec3();
// Convert the ray to local heightfield coordinates
var localRay = new Ray(this.from, this.to);
Transform.pointToLocalFrame(position, quat, localRay.from, localRay.from);
Transform.pointToLocalFrame(position, quat, localRay.to, localRay.to);
// Get the index of the data points to test against
var index = [];
var iMinX = null;
var iMinY = null;
var iMaxX = null;
var iMaxY = null;
var inside = shape.getIndexOfPosition(localRay.from.x, localRay.from.y, index, false);
if(inside){
iMinX = index[0];
iMinY = index[1];
iMaxX = index[0];
iMaxY = index[1];
}
inside = shape.getIndexOfPosition(localRay.to.x, localRay.to.y, index, false);
if(inside){
if (iMinX === null || index[0] < iMinX) { iMinX = index[0]; }
if (iMaxX === null || index[0] > iMaxX) { iMaxX = index[0]; }
if (iMinY === null || index[1] < iMinY) { iMinY = index[1]; }
if (iMaxY === null || index[1] > iMaxY) { iMaxY = index[1]; }
}
if(iMinX === null){
return result;
}
var minMax = [];
shape.getRectMinMax(iMinX, iMinY, iMaxX, iMaxY, minMax);
var min = minMax[0];
var max = minMax[1];
// // Bail out if the ray can't touch the bounding box
// // TODO
// var aabb = new AABB();
// this.getAABB(aabb);
// if(aabb.intersects()){
// return;
// }
for(var i = iMinX; i <= iMaxX; i++){
for(var j = iMinY; j <= iMaxY; j++){
// Lower triangle
shape.getConvexTrianglePillar(i, j, false);
Transform.pointToWorldFrame(position, quat, shape.pillarOffset, worldPillarOffset);
this.intersectConvex(shape.pillarConvex, quat, worldPillarOffset, body, direction, result, intersectConvexOptions);
// Upper triangle
shape.getConvexTrianglePillar(i, j, true);
Transform.pointToWorldFrame(position, quat, shape.pillarOffset, worldPillarOffset);
this.intersectConvex(shape.pillarConvex, quat, worldPillarOffset, body, direction, result, intersectConvexOptions);
}
}
return result;
};
Ray.prototype[Shape.types.HEIGHTFIELD] = Ray.prototype.intersectHeightfield;
Ray.prototype.intersectSphere = function(shape, quat, position, body, direction, result){
var from = this.from,
to = this.to,
r = shape.radius;
var a = Math.pow(to.x - from.x, 2) + Math.pow(to.y - from.y, 2) + Math.pow(to.z - from.z, 2);
var b = 2 * ((to.x - from.x) * (from.x - position.x) + (to.y - from.y) * (from.y - position.y) + (to.z - from.z) * (from.z - position.z));
var c = Math.pow(from.x - position.x, 2) + Math.pow(from.y - position.y, 2) + Math.pow(from.z - position.z, 2) - Math.pow(r, 2);
var delta = Math.pow(b, 2) - 4 * a * c;
if(delta < 0){
// No intersection
return result;
} else if(delta === 0){
// single intersection point
var intersectionPoint = new Vec3();
from.lerp(to, delta, intersectionPoint);
var normal = new Vec3();
intersectionPoint.vsub(position, normal);
normal.normalize();
if(this.reportIntersection(normal, intersectionPoint, shape, body, result)){
return result;
}
} else {
var d1 = (- b - Math.sqrt(delta)) / (2 * a);
var d2 = (- b + Math.sqrt(delta)) / (2 * a);
var intersectionPoint = new Vec3();
from.lerp(to, d1, intersectionPoint);
var normal = new Vec3();
intersectionPoint.vsub(position, normal);
normal.normalize();
if(this.reportIntersection(normal, intersectionPoint, shape, body, result)){
return result;
}
from.lerp(to, d2, intersectionPoint);
var normal = new Vec3();
intersectionPoint.vsub(position, normal);
normal.normalize();
if(this.reportIntersection(normal, intersectionPoint, shape, body, result)){
return result;
}
}
return result;
};
Ray.prototype[Shape.types.SPHERE] = Ray.prototype.intersectSphere;
var intersectConvex_minDistNormal = new Vec3();
var intersectConvex_minDistIntersect = new Vec3();
Ray.prototype.intersectConvex = function intersectConvex(shape, quat, position, body, direction, result, options){
var minDistNormal = intersectConvex_minDistNormal;
var minDistIntersect = intersectConvex_minDistIntersect;
var faceList = (options && options.faceList) || null;
// Checking faces
var faces = shape.faces,
vertices = shape.vertices,
normals = shape.faceNormals;
var from = this.from;
var to = this.to;
var fromToDistance = from.distanceTo(to);
var reportClosest = result instanceof RaycastResult;
var minDist = -1;
var Nfaces = faceList ? faceList.length : faces.length;
for (var j = 0; j < Nfaces; j++) {
var fi = faceList ? faceList[j] : j;
var face = faces[fi];
var faceNormal = normals[fi];
var q = quat;
var x = position;
// determine if ray intersects the plane of the face
// note: this works regardless of the direction of the face normal
// Get plane point in world coordinates...
vector.copy(vertices[face[0]]);
q.vmult(vector,vector);
vector.vadd(x,vector);
// ...but make it relative to the ray from. We'll fix this later.
vector.vsub(from,vector);
// Get plane normal
q.vmult(faceNormal,normal);
// If this dot product is negative, we have something interesting
var dot = direction.dot(normal);
// Bail out if ray and plane are parallel
if ( Math.abs( dot ) < this.precision ){
continue;
}
// calc distance to plane
var scalar = normal.dot(vector) / dot;
// if negative distance, then plane is behind ray
if (scalar < 0){
continue;
}
if (dot < 0) {
// Intersection point is from + direction * scalar
direction.mult(scalar,intersectPoint);
intersectPoint.vadd(from,intersectPoint);
// a is the point we compare points b and c with.
a.copy(vertices[face[0]]);
q.vmult(a,a);
x.vadd(a,a);
for(var i = 1; i < face.length - 1; i++){
// Transform 3 vertices to world coords
b.copy(vertices[face[i]]);
c.copy(vertices[face[i+1]]);
q.vmult(b,b);
q.vmult(c,c);
x.vadd(b,b);
x.vadd(c,c);
var distance = intersectPoint.distanceTo(from);
if(!pointInTriangle(intersectPoint, a, b, c) || distance > fromToDistance){
continue;
}
if(minDist === -1 || distance < minDist){
minDist = distance;
minDistNormal.copy(normal);
minDistIntersect.copy(intersectPoint);
}
}
}
}
if(minDist !== -1 && this.reportIntersection(minDistNormal, minDistIntersect, shape, body, result)){
return result;
}
return result;
};
Ray.prototype[Shape.types.CONVEXPOLYHEDRON] = Ray.prototype.intersectConvex;
Ray.prototype.reportIntersection = function(normal, hitPointWorld, shape, body, result){
var from = this.from;
var to = this.to;
var distance = from.distanceTo(hitPointWorld);
if(!(result instanceof RaycastResult)){
// Got a callback
tmpRaycastResult.set(
from,
to,
normal,
hitPointWorld,
shape,
body,
distance
);
tmpRaycastResult.hasHit = true;
result(tmpRaycastResult);
return true;
} else {
// Store if closer than current cloest
if(distance < result.distance || !result.hasHit){
result.hasHit = true;
result.set(
from,
to,
normal,
hitPointWorld,
shape,
body,
distance
);
}
return false;
}
};
var v0 = new Vec3(),
intersect = new Vec3();
function distanceFromIntersection(from, direction, position) {
// v0 is vector from from to position
position.vsub(from,v0);
var dot = v0.dot( direction );
// intersect = direction*dot + from
direction.mult(dot,intersect);
intersect.vadd(from,intersect);
var distance = position.distanceTo(intersect);
return distance;
}