@awayfl/awayfl-player
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Flash Player emulator for executing SWF files (published for FP versions 6 and up) in javascript
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JavaScript
/*
* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
import { b2Vec2 } from '../Common/Math';
// A manifold for two touching convex shapes.
var b2Segment = /** @class */ (function () {
function b2Segment() {
this.p1 = new b2Vec2(); ///< the starting point
this.p2 = new b2Vec2(); ///< the ending point
}
/// Ray cast against this segment with another segment.
// Collision Detection in Interactive 3D Environments by Gino van den Bergen
// From Section 3.4.1
// x = mu1 * p1 + mu2 * p2
// mu1 + mu2 = 1 && mu1 >= 0 && mu2 >= 0
// mu1 = 1 - mu2;
// x = (1 - mu2) * p1 + mu2 * p2
// = p1 + mu2 * (p2 - p1)
// x = s + a * r (s := start, r := end - start)
// s + a * r = p1 + mu2 * d (d := p2 - p1)
// -a * r + mu2 * d = b (b := s - p1)
// [-r d] * [a; mu2] = b
// Cramer's rule:
// denom = det[-r d]
// a = det[b d] / denom
// mu2 = det[-r b] / denom
b2Segment.prototype.TestSegment = function (lambda, // float pointer
normal, // pointer
segment, maxLambda) {
//b2Vec2 s = segment.p1;
var s = segment.p1;
//b2Vec2 r = segment.p2 - s;
var rX = segment.p2.x - s.x;
var rY = segment.p2.y - s.y;
//b2Vec2 d = this.p2 - this.p1;
var dX = this.p2.x - this.p1.x;
var dY = this.p2.y - this.p1.y;
//b2Vec2 n = b2Cross(d, 1.0f);
var nX = dY;
var nY = -dX;
var k_slop = 100.0 * Number.MIN_VALUE;
//var denom:number = -b2Dot(r, n);
var denom = -(rX * nX + rY * nY);
// Cull back facing collision and ignore parallel segments.
if (denom > k_slop) {
// Does the segment intersect the infinite line associated with this segment?
//b2Vec2 b = s - p1;
var bX = s.x - this.p1.x;
var bY = s.y - this.p1.y;
//var a:number = b2Dot(b, n);
var a = (bX * nX + bY * nY);
if (0.0 <= a && a <= maxLambda * denom) {
var mu2 = -rY * bY + rY * bX;
// Does the segment intersect this segment?
if (-k_slop * denom <= mu2 && mu2 <= denom * (1.0 + k_slop)) {
a /= denom;
//n.Normalize();
var nLen = Math.sqrt(nX * nX + nY * nY);
nX /= nLen;
nY /= nLen;
//*lambda = a;
lambda[0] = a;
//*normal = n;
normal.Set(nX, nY);
return true;
}
}
}
return false;
};
/// Extends or clips the segment so that it's ends lie on the boundary of the AABB
b2Segment.prototype.Extend = function (aabb) {
this.ExtendForward(aabb);
this.ExtendBackward(aabb);
};
/// @see Extend
b2Segment.prototype.ExtendForward = function (aabb) {
var dX = this.p2.x - this.p1.x;
var dY = this.p2.y - this.p1.y;
var lambda = Math.min(dX > 0
? (aabb.upperBound.x - this.p1.x) / dX
: dX < 0
? (aabb.lowerBound.x - this.p1.x) / dX
: Number.POSITIVE_INFINITY, dY > 0
? (aabb.upperBound.y - this.p1.y) / dY
: dY < 0
? (aabb.lowerBound.y - this.p1.y) / dY
: Number.POSITIVE_INFINITY);
this.p2.x = this.p1.x + dX * lambda;
this.p2.y = this.p1.y + dY * lambda;
};
/// @see Extend
b2Segment.prototype.ExtendBackward = function (aabb) {
var dX = -this.p2.x + this.p1.x;
var dY = -this.p2.y + this.p1.y;
var lambda = Math.min(dX > 0 ? (aabb.upperBound.x - this.p2.x) / dX : dX < 0 ? (aabb.lowerBound.x - this.p2.x) / dX : Number.POSITIVE_INFINITY, dY > 0 ? (aabb.upperBound.y - this.p2.y) / dY : dY < 0 ? (aabb.lowerBound.y - this.p2.y) / dY : Number.POSITIVE_INFINITY);
this.p1.x = this.p2.x + dX * lambda;
this.p1.y = this.p2.y + dY * lambda;
};
return b2Segment;
}());
export { b2Segment };