1 /**
  2  Copyright (c) 2010-2012 cocos2d-x.org
  3  Copyright (c) 2008, Luke Benstead.
  4  All rights reserved.
  5 
  6  Redistribution and use in source and binary forms, with or without modification,
  7  are permitted provided that the following conditions are met:
  8 
  9  Redistributions of source code must retain the above copyright notice,
 10  this list of conditions and the following disclaimer.
 11  Redistributions in binary form must reproduce the above copyright notice,
 12  this list of conditions and the following disclaimer in the documentation
 13  and/or other materials provided with the distribution.
 14 
 15  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 16  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 17  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 18  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 19  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 20  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 21  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 22  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 23  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 24  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 25  */
 26 
 27 cc.KM_PLANE_LEFT = 0;
 28 
 29 cc.KM_PLANE_RIGHT = 1;
 30 
 31 cc.KM_PLANE_BOTTOM = 2;
 32 
 33 cc.KM_PLANE_TOP = 3;
 34 
 35 cc.KM_PLANE_NEAR = 4;
 36 
 37 cc.KM_PLANE_FAR = 5;
 38 
 39 cc.kmPlane = function (a, b, c, d) {
 40     this.a = a || 0;
 41     this.b = b || 0;
 42     this.c = c || 0;
 43     this.d = d || 0;
 44 };
 45 
 46 cc.POINT_INFRONT_OF_PLANE = 0;
 47 
 48 cc.POINT_BEHIND_PLANE = 1;
 49 
 50 cc.POINT_ON_PLANE = 2;
 51 
 52 cc.kmPlaneDot = function(pP, pV){
 53     //a*x + b*y + c*z + d*w
 54     return (pP.a * pV.x +
 55         pP.b * pV.y +
 56         pP.c * pV.z +
 57         pP.d * pV.w);
 58 };
 59 
 60 cc.kmPlaneDotCoord = function(pP, pV){
 61     return (pP.a * pV.x +
 62         pP.b * pV.y +
 63         pP.c * pV.z + pP.d);
 64 };
 65 
 66 cc.kmPlaneDotNormal = function(pP, pV){
 67     return (pP.a * pV.x +
 68         pP.b * pV.y +
 69         pP.c * pV.z);
 70 };
 71 
 72 cc.kmPlaneFromPointNormal = function(pOut, pPoint, pNormal){
 73     /*
 74      Planea = Nx
 75      Planeb = Ny
 76      Planec = Nz
 77      Planed = −N⋅P
 78      */
 79     pOut.a = pNormal.x;
 80     pOut.b = pNormal.y;
 81     pOut.c = pNormal.z;
 82     pOut.d = -cc.kmVec3Dot(pNormal, pPoint);
 83 
 84     return pOut;
 85 };
 86 
 87 /**
 88  * Creates a plane from 3 points. The result is stored in pOut.
 89  * pOut is returned.
 90  */
 91 cc.kmPlaneFromPoints = function(pOut, p1, p2, p3){
 92     /*
 93      v = (B − A) × (C − A)
 94      n = 1⁄|v| v
 95      Outa = nx
 96      Outb = ny
 97      Outc = nz
 98      Outd = −n⋅A
 99      */
100 
101     var n = new cc.kmVec3(), v1 = new cc.kmVec3(), v2 = new cc.kmVec3();
102     cc.kmVec3Subtract(v1, p2, p1); //Create the vectors for the 2 sides of the triangle
103     cc.kmVec3Subtract(v2, p3, p1);
104     cc.kmVec3Cross(n, v1, v2); //Use the cross product to get the normal
105 
106     cc.kmVec3Normalize(n, n); //Normalize it and assign to pOut.m_N
107 
108     pOut.a = n.x;
109     pOut.b = n.y;
110     pOut.c = n.z;
111     pOut.d = cc.kmVec3Dot(cc.kmVec3Scale(n, n, -1.0), p1);
112 
113     return pOut;
114 };
115 
116 cc.kmPlaneIntersectLine = function(pOut, pP, pV1, pV2){
117     throw "cc.kmPlaneIntersectLine() hasn't been implemented.";
118     /*
119      n = (Planea, Planeb, Planec)
120      d = V − U
121      Out = U − d⋅(Pd + n⋅U)⁄(d⋅n) [iff d⋅n ≠ 0]
122      */
123     //var d = new cc.kmVec3();
124 
125     //cc.kmVec3Subtract(d, pV2, pV1); //Get the direction vector
126 
127     //TODO: Continue here!
128     /*if (fabs(kmVec3Dot(&pP.m_N, &d)) > kmEpsilon)
129      {
130      //If we get here then the plane and line are parallel (i.e. no intersection)
131      pOut = nullptr; //Set to nullptr
132 
133      return pOut;
134      } */
135 
136     //return null;
137 };
138 
139 cc.kmPlaneNormalize = function(pOut, pP){
140     var n = new cc.kmVec3();
141 
142     n.x = pP.a;
143     n.y = pP.b;
144     n.z = pP.c;
145 
146     var l = 1.0 / cc.kmVec3Length(n); //Get 1/length
147     cc.kmVec3Normalize(n, n); //Normalize the vector and assign to pOut
148 
149     pOut.a = n.x;
150     pOut.b = n.y;
151     pOut.c = n.z;
152 
153     pOut.d = pP.d * l; //Scale the D value and assign to pOut
154 
155     return pOut;
156 };
157 
158 cc.kmPlaneScale = function(pOut, pP, s){
159     cc.log("cc.kmPlaneScale() has not been implemented.");
160 };
161 
162 /**
163  * Returns POINT_INFRONT_OF_PLANE if pP is infront of pIn. Returns
164  * POINT_BEHIND_PLANE if it is behind. Returns POINT_ON_PLANE otherwise
165  */
166 cc.kmPlaneClassifyPoint = function(pIn, pP){
167     // This function will determine if a point is on, in front of, or behind
168     // the plane.  First we store the dot product of the plane and the point.
169     var distance = pIn.a * pP.x + pIn.b * pP.y + pIn.c * pP.z + pIn.d;
170 
171     // Simply put if the dot product is greater than 0 then it is infront of it.
172     // If it is less than 0 then it is behind it.  And if it is 0 then it is on it.
173     if(distance > 0.001) return cc.POINT_INFRONT_OF_PLANE;
174     if(distance < -0.001) return cc.POINT_BEHIND_PLANE;
175 
176     return cc.POINT_ON_PLANE;
177 };
178 
179 
180