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Viewing changes to src/components/ogre/ogreopcode/include/Opcode/OPC_SphereTriOverlap.h

  • Committer: Bazaar Package Importer
  • Author(s): Michael Koch
  • Date: 2009-07-23 07:46:40 UTC
  • Revision ID: james.westby@ubuntu.com-20090723074640-wh0ukzis0kda36qv
Tags: upstream-0.5.6
Import upstream version 0.5.6

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src/components/ogre/ogreopcode/include/Opcode/OPC_SphereTriOverlap.h
 
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// This is collision detection. If you do another distance test for collision *response*,
 
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// if might be useful to simply *skip* the test below completely, and report a collision.
 
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// - if sphere-triangle overlap, result is ok
 
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// - if they don't, we'll discard them during collision response with a similar test anyway
 
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// Overall this approach should run faster.
 
7
 
 
8
// Original code by David Eberly in Magic.
 
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BOOL SphereCollider::SphereTriOverlap(const IceMaths::Point& vert0_, const IceMaths::Point& vert1_, const IceMaths::Point& vert2_)
 
10
{
 
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        // Stats
 
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        mNbVolumePrimTests++;
 
13
 
 
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        // applies the model's local scale
 
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        IceMaths::Point vert0 = vert0_*mLocalScale;
 
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        IceMaths::Point vert1 = vert1_*mLocalScale;
 
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        IceMaths::Point vert2 = vert2_*mLocalScale;
 
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        // Early exit if one of the vertices is inside the sphere
 
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        IceMaths::Point kDiff = vert2 - mCenter;
 
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        float fC = kDiff.SquareMagnitude();
 
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        if(fC <= mRadius2)      return TRUE;
 
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        kDiff = vert1 - mCenter;
 
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        fC = kDiff.SquareMagnitude();
 
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        if(fC <= mRadius2)      return TRUE;
 
27
 
 
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        kDiff = vert0 - mCenter;
 
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        fC = kDiff.SquareMagnitude();
 
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        if(fC <= mRadius2)      return TRUE;
 
31
 
 
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        // Else do the full distance test
 
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        IceMaths::Point TriEdge0        = vert1 - vert0;
 
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        IceMaths::Point TriEdge1        = vert2 - vert0;
 
35
 
 
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//Point kDiff   = vert0 - mCenter;
 
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        float fA00      = TriEdge0.SquareMagnitude();
 
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        float fA01      = TriEdge0 | TriEdge1;
 
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        float fA11      = TriEdge1.SquareMagnitude();
 
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        float fB0       = kDiff | TriEdge0;
 
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        float fB1       = kDiff | TriEdge1;
 
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//float fC      = kDiff.SquareMagnitude();
 
43
        float fDet      = fabsf(fA00*fA11 - fA01*fA01);
 
44
        float u         = fA01*fB1-fA11*fB0;
 
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        float v         = fA01*fB0-fA00*fB1;
 
46
        float SqrDist;
 
47
 
 
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        if(u + v <= fDet)
 
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        {
 
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                if(u < 0.0f)
 
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                {
 
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                        if(v < 0.0f)  // region 4
 
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                        {
 
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                                if(fB0 < 0.0f)
 
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                                {
 
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//                                      v = 0.0f;
 
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                                        if(-fB0>=fA00)                  { /*u = 1.0f;*/         SqrDist = fA00+2.0f*fB0+fC;     }
 
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                                        else                                    { u = -fB0/fA00;        SqrDist = fB0*u+fC;                     }
 
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                                }
 
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                                else
 
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                                {
 
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//                                      u = 0.0f;
 
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                                        if(fB1>=0.0f)                   { /*v = 0.0f;*/         SqrDist = fC;                           }
 
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                                        else if(-fB1>=fA11)             { /*v = 1.0f;*/         SqrDist = fA11+2.0f*fB1+fC;     }
 
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                                        else                                    { v = -fB1/fA11;        SqrDist = fB1*v+fC;                     }
 
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                                }
 
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                        }
 
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                        else  // region 3
 
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                        {
 
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//                              u = 0.0f;
 
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                                if(fB1>=0.0f)                           { /*v = 0.0f;*/         SqrDist = fC;                           }
 
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                                else if(-fB1>=fA11)                     { /*v = 1.0f;*/         SqrDist = fA11+2.0f*fB1+fC;     }
 
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                                else                                            { v = -fB1/fA11;        SqrDist = fB1*v+fC;                     }
 
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                        }
 
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                }
 
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                else if(v < 0.0f)  // region 5
 
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                {
 
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//                      v = 0.0f;
 
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                        if(fB0>=0.0f)                                   { /*u = 0.0f;*/         SqrDist = fC;                           }
 
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                        else if(-fB0>=fA00)                             { /*u = 1.0f;*/         SqrDist = fA00+2.0f*fB0+fC;     }
 
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                        else                                                    { u = -fB0/fA00;        SqrDist = fB0*u+fC;                     }
 
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                }
 
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                else  // region 0
 
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                {
 
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                        // minimum at interior point
 
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                        if(fDet==0.0f)
 
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                        {
 
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//                              u = 0.0f;
 
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//                              v = 0.0f;
 
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                                SqrDist = MAX_FLOAT;
 
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                        }
 
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                        else
 
93
                        {
 
94
                                float fInvDet = 1.0f/fDet;
 
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                                u *= fInvDet;
 
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                                v *= fInvDet;
 
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                                SqrDist = u*(fA00*u+fA01*v+2.0f*fB0) + v*(fA01*u+fA11*v+2.0f*fB1)+fC;
 
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                        }
 
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                }
 
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        }
 
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        else
 
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        {
 
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                float fTmp0, fTmp1, fNumer, fDenom;
 
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                if(u < 0.0f)  // region 2
 
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                {
 
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                        fTmp0 = fA01 + fB0;
 
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                        fTmp1 = fA11 + fB1;
 
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                        if(fTmp1 > fTmp0)
 
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                        {
 
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                                fNumer = fTmp1 - fTmp0;
 
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                                fDenom = fA00-2.0f*fA01+fA11;
 
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                                if(fNumer >= fDenom)
 
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                                {
 
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//                                      u = 1.0f;
 
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//                                      v = 0.0f;
 
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                                        SqrDist = fA00+2.0f*fB0+fC;
 
118
                                }
 
119
                                else
 
120
                                {
 
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                                        u = fNumer/fDenom;
 
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                                        v = 1.0f - u;
 
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                                        SqrDist = u*(fA00*u+fA01*v+2.0f*fB0) + v*(fA01*u+fA11*v+2.0f*fB1)+fC;
 
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                                }
 
125
                        }
 
126
                        else
 
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                        {
 
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//                              u = 0.0f;
 
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                                if(fTmp1 <= 0.0f)               { /*v = 1.0f;*/         SqrDist = fA11+2.0f*fB1+fC;     }
 
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                                else if(fB1 >= 0.0f)    { /*v = 0.0f;*/         SqrDist = fC;                           }
 
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                                else                                    { v = -fB1/fA11;        SqrDist = fB1*v+fC;                     }
 
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                        }
 
133
                }
 
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                else if(v < 0.0f)  // region 6
 
135
                {
 
136
                        fTmp0 = fA01 + fB1;
 
137
                        fTmp1 = fA00 + fB0;
 
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                        if(fTmp1 > fTmp0)
 
139
                        {
 
140
                                fNumer = fTmp1 - fTmp0;
 
141
                                fDenom = fA00-2.0f*fA01+fA11;
 
142
                                if(fNumer >= fDenom)
 
143
                                {
 
144
//                                      v = 1.0f;
 
145
//                                      u = 0.0f;
 
146
                                        SqrDist = fA11+2.0f*fB1+fC;
 
147
                                }
 
148
                                else
 
149
                                {
 
150
                                        v = fNumer/fDenom;
 
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                                        u = 1.0f - v;
 
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                                        SqrDist = u*(fA00*u+fA01*v+2.0f*fB0) + v*(fA01*u+fA11*v+2.0f*fB1)+fC;
 
153
                                }
 
154
                        }
 
155
                        else
 
156
                        {
 
157
//                              v = 0.0f;
 
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                                if(fTmp1 <= 0.0f)               { /*u = 1.0f;*/         SqrDist = fA00+2.0f*fB0+fC;     }
 
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                                else if(fB0 >= 0.0f)    { /*u = 0.0f;*/         SqrDist = fC;                           }
 
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                                else                                    { u = -fB0/fA00;        SqrDist = fB0*u+fC;                     }
 
161
                        }
 
162
                }
 
163
                else  // region 1
 
164
                {
 
165
                        fNumer = fA11 + fB1 - fA01 - fB0;
 
166
                        if(fNumer <= 0.0f)
 
167
                        {
 
168
//                              u = 0.0f;
 
169
//                              v = 1.0f;
 
170
                                SqrDist = fA11+2.0f*fB1+fC;
 
171
                        }
 
172
                        else
 
173
                        {
 
174
                                fDenom = fA00-2.0f*fA01+fA11;
 
175
                                if(fNumer >= fDenom)
 
176
                                {
 
177
//                                      u = 1.0f;
 
178
//                                      v = 0.0f;
 
179
                                        SqrDist = fA00+2.0f*fB0+fC;
 
180
                                }
 
181
                                else
 
182
                                {
 
183
                                        u = fNumer/fDenom;
 
184
                                        v = 1.0f - u;
 
185
                                        SqrDist = u*(fA00*u+fA01*v+2.0f*fB0) + v*(fA01*u+fA11*v+2.0f*fB1)+fC;
 
186
                                }
 
187
                        }
 
188
                }
 
189
        }
 
190
 
 
191
        return fabsf(SqrDist) < mRadius2;
 
192
}