340 lines
11 KiB
C
340 lines
11 KiB
C
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//! This macro quickly finds the min & max values among 3 variables
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#define FINDMINMAX(x0, x1, x2, min, max) \
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min = max = x0; \
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if(x1<min) min=x1; \
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if(x1>max) max=x1; \
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if(x2<min) min=x2; \
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if(x2>max) max=x2;
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//! TO BE DOCUMENTED
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inline_ BOOL planeBoxOverlap(const Point& normal, const float d, const Point& maxbox)
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{
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Point vmin, vmax;
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for(udword q=0;q<=2;q++)
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{
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if(normal[q]>0.0f) { vmin[q]=-maxbox[q]; vmax[q]=maxbox[q]; }
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else { vmin[q]=maxbox[q]; vmax[q]=-maxbox[q]; }
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}
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if((normal|vmin)+d>0.0f) return FALSE;
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if((normal|vmax)+d>=0.0f) return TRUE;
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return FALSE;
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}
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//! TO BE DOCUMENTED
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#define AXISTEST_X01(a, b, fa, fb) \
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min = a*v0.y - b*v0.z; \
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max = a*v2.y - b*v2.z; \
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if(min>max) {const float tmp=max; max=min; min=tmp; } \
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rad = fa * extents.y + fb * extents.z; \
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if(min>rad || max<-rad) return FALSE;
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//! TO BE DOCUMENTED
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#define AXISTEST_X2(a, b, fa, fb) \
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min = a*v0.y - b*v0.z; \
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max = a*v1.y - b*v1.z; \
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if(min>max) {const float tmp=max; max=min; min=tmp; } \
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rad = fa * extents.y + fb * extents.z; \
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if(min>rad || max<-rad) return FALSE;
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//! TO BE DOCUMENTED
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#define AXISTEST_Y02(a, b, fa, fb) \
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min = b*v0.z - a*v0.x; \
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max = b*v2.z - a*v2.x; \
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if(min>max) {const float tmp=max; max=min; min=tmp; } \
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rad = fa * extents.x + fb * extents.z; \
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if(min>rad || max<-rad) return FALSE;
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//! TO BE DOCUMENTED
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#define AXISTEST_Y1(a, b, fa, fb) \
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min = b*v0.z - a*v0.x; \
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max = b*v1.z - a*v1.x; \
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if(min>max) {const float tmp=max; max=min; min=tmp; } \
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rad = fa * extents.x + fb * extents.z; \
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if(min>rad || max<-rad) return FALSE;
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//! TO BE DOCUMENTED
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#define AXISTEST_Z12(a, b, fa, fb) \
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min = a*v1.x - b*v1.y; \
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max = a*v2.x - b*v2.y; \
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if(min>max) {const float tmp=max; max=min; min=tmp; } \
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rad = fa * extents.x + fb * extents.y; \
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if(min>rad || max<-rad) return FALSE;
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//! TO BE DOCUMENTED
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#define AXISTEST_Z0(a, b, fa, fb) \
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min = a*v0.x - b*v0.y; \
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max = a*v1.x - b*v1.y; \
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if(min>max) {const float tmp=max; max=min; min=tmp; } \
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rad = fa * extents.x + fb * extents.y; \
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if(min>rad || max<-rad) return FALSE;
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// compute triangle edges
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// - edges lazy evaluated to take advantage of early exits
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// - fabs precomputed (half less work, possible since extents are always >0)
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// - customized macros to take advantage of the null component
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// - axis vector discarded, possibly saves useless movs
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#define IMPLEMENT_CLASS3_TESTS \
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float rad; \
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float min, max; \
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\
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const float fey0 = fabsf(e0.y); \
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const float fez0 = fabsf(e0.z); \
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AXISTEST_X01(e0.z, e0.y, fez0, fey0); \
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const float fex0 = fabsf(e0.x); \
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AXISTEST_Y02(e0.z, e0.x, fez0, fex0); \
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AXISTEST_Z12(e0.y, e0.x, fey0, fex0); \
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\
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const float fey1 = fabsf(e1.y); \
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const float fez1 = fabsf(e1.z); \
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AXISTEST_X01(e1.z, e1.y, fez1, fey1); \
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const float fex1 = fabsf(e1.x); \
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AXISTEST_Y02(e1.z, e1.x, fez1, fex1); \
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AXISTEST_Z0(e1.y, e1.x, fey1, fex1); \
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\
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const Point e2 = mLeafVerts[0] - mLeafVerts[2]; \
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const float fey2 = fabsf(e2.y); \
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const float fez2 = fabsf(e2.z); \
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AXISTEST_X2(e2.z, e2.y, fez2, fey2); \
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const float fex2 = fabsf(e2.x); \
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AXISTEST_Y1(e2.z, e2.x, fez2, fex2); \
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AXISTEST_Z12(e2.y, e2.x, fey2, fex2);
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///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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/**
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* Triangle-Box overlap test using the separating axis theorem.
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* This is the code from Tomas M<>ller, a bit optimized:
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* - with some more lazy evaluation (faster path on PC)
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* - with a tiny bit of assembly
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* - with "SAT-lite" applied if needed
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* - and perhaps with some more minor modifs...
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*
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* \param center [in] box center
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* \param extents [in] box extents
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* \return true if triangle & box overlap
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*/
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///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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inline_ BOOL AABBTreeCollider::TriBoxOverlap(const Point& center, const Point& extents)
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{
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// Stats
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mNbBVPrimTests++;
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// use separating axis theorem to test overlap between triangle and box
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// need to test for overlap in these directions:
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// 1) the {x,y,z}-directions (actually, since we use the AABB of the triangle
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// we do not even need to test these)
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// 2) normal of the triangle
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// 3) crossproduct(edge from tri, {x,y,z}-directin)
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// this gives 3x3=9 more tests
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// move everything so that the boxcenter is in (0,0,0)
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Point v0, v1, v2;
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v0.x = mLeafVerts[0].x - center.x;
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v1.x = mLeafVerts[1].x - center.x;
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v2.x = mLeafVerts[2].x - center.x;
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// First, test overlap in the {x,y,z}-directions
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#ifdef OPC_USE_FCOMI
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// find min, max of the triangle in x-direction, and test for overlap in X
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if(FCMin3(v0.x, v1.x, v2.x)>extents.x) return FALSE;
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if(FCMax3(v0.x, v1.x, v2.x)<-extents.x) return FALSE;
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// same for Y
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v0.y = mLeafVerts[0].y - center.y;
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v1.y = mLeafVerts[1].y - center.y;
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v2.y = mLeafVerts[2].y - center.y;
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if(FCMin3(v0.y, v1.y, v2.y)>extents.y) return FALSE;
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if(FCMax3(v0.y, v1.y, v2.y)<-extents.y) return FALSE;
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// same for Z
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v0.z = mLeafVerts[0].z - center.z;
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v1.z = mLeafVerts[1].z - center.z;
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v2.z = mLeafVerts[2].z - center.z;
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if(FCMin3(v0.z, v1.z, v2.z)>extents.z) return FALSE;
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if(FCMax3(v0.z, v1.z, v2.z)<-extents.z) return FALSE;
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#else
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float min,max;
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// Find min, max of the triangle in x-direction, and test for overlap in X
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FINDMINMAX(v0.x, v1.x, v2.x, min, max);
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if(min>extents.x || max<-extents.x) return FALSE;
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// Same for Y
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v0.y = mLeafVerts[0].y - center.y;
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v1.y = mLeafVerts[1].y - center.y;
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v2.y = mLeafVerts[2].y - center.y;
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FINDMINMAX(v0.y, v1.y, v2.y, min, max);
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if(min>extents.y || max<-extents.y) return FALSE;
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// Same for Z
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v0.z = mLeafVerts[0].z - center.z;
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v1.z = mLeafVerts[1].z - center.z;
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v2.z = mLeafVerts[2].z - center.z;
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FINDMINMAX(v0.z, v1.z, v2.z, min, max);
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if(min>extents.z || max<-extents.z) return FALSE;
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#endif
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// 2) Test if the box intersects the plane of the triangle
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// compute plane equation of triangle: normal*x+d=0
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// ### could be precomputed since we use the same leaf triangle several times
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const Point e0 = v1 - v0;
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const Point e1 = v2 - v1;
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const Point normal = e0 ^ e1;
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const float d = -normal|v0;
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if(!planeBoxOverlap(normal, d, extents)) return FALSE;
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// 3) "Class III" tests
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if(mFullPrimBoxTest)
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{
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IMPLEMENT_CLASS3_TESTS
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}
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return TRUE;
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}
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//! A dedicated version where the box is constant
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inline_ BOOL OBBCollider::TriBoxOverlap()
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{
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// Stats
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mNbVolumePrimTests++;
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// Hook
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const Point& extents = mBoxExtents;
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const Point& v0 = mLeafVerts[0];
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const Point& v1 = mLeafVerts[1];
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const Point& v2 = mLeafVerts[2];
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// use separating axis theorem to test overlap between triangle and box
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// need to test for overlap in these directions:
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// 1) the {x,y,z}-directions (actually, since we use the AABB of the triangle
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// we do not even need to test these)
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// 2) normal of the triangle
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// 3) crossproduct(edge from tri, {x,y,z}-directin)
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// this gives 3x3=9 more tests
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// Box center is already in (0,0,0)
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// First, test overlap in the {x,y,z}-directions
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#ifdef OPC_USE_FCOMI
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// find min, max of the triangle in x-direction, and test for overlap in X
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if(FCMin3(v0.x, v1.x, v2.x)>mBoxExtents.x) return FALSE;
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if(FCMax3(v0.x, v1.x, v2.x)<-mBoxExtents.x) return FALSE;
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if(FCMin3(v0.y, v1.y, v2.y)>mBoxExtents.y) return FALSE;
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if(FCMax3(v0.y, v1.y, v2.y)<-mBoxExtents.y) return FALSE;
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if(FCMin3(v0.z, v1.z, v2.z)>mBoxExtents.z) return FALSE;
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if(FCMax3(v0.z, v1.z, v2.z)<-mBoxExtents.z) return FALSE;
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#else
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float min,max;
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// Find min, max of the triangle in x-direction, and test for overlap in X
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FINDMINMAX(v0.x, v1.x, v2.x, min, max);
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if(min>mBoxExtents.x || max<-mBoxExtents.x) return FALSE;
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FINDMINMAX(v0.y, v1.y, v2.y, min, max);
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if(min>mBoxExtents.y || max<-mBoxExtents.y) return FALSE;
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FINDMINMAX(v0.z, v1.z, v2.z, min, max);
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if(min>mBoxExtents.z || max<-mBoxExtents.z) return FALSE;
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#endif
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// 2) Test if the box intersects the plane of the triangle
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// compute plane equation of triangle: normal*x+d=0
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// ### could be precomputed since we use the same leaf triangle several times
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const Point e0 = v1 - v0;
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const Point e1 = v2 - v1;
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const Point normal = e0 ^ e1;
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const float d = -normal|v0;
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if(!planeBoxOverlap(normal, d, mBoxExtents)) return FALSE;
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// 3) "Class III" tests - here we always do full tests since the box is a primitive (not a BV)
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{
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IMPLEMENT_CLASS3_TESTS
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}
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return TRUE;
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}
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//! ...and another one, jeez
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inline_ BOOL AABBCollider::TriBoxOverlap()
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{
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// Stats
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mNbVolumePrimTests++;
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// Hook
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const Point& center = mBox.mCenter;
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const Point& extents = mBox.mExtents;
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// use separating axis theorem to test overlap between triangle and box
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// need to test for overlap in these directions:
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// 1) the {x,y,z}-directions (actually, since we use the AABB of the triangle
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// we do not even need to test these)
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// 2) normal of the triangle
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// 3) crossproduct(edge from tri, {x,y,z}-directin)
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// this gives 3x3=9 more tests
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// move everything so that the boxcenter is in (0,0,0)
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Point v0, v1, v2;
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v0.x = mLeafVerts[0].x - center.x;
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v1.x = mLeafVerts[1].x - center.x;
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v2.x = mLeafVerts[2].x - center.x;
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// First, test overlap in the {x,y,z}-directions
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#ifdef OPC_USE_FCOMI
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// find min, max of the triangle in x-direction, and test for overlap in X
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if(FCMin3(v0.x, v1.x, v2.x)>extents.x) return FALSE;
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if(FCMax3(v0.x, v1.x, v2.x)<-extents.x) return FALSE;
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// same for Y
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v0.y = mLeafVerts[0].y - center.y;
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v1.y = mLeafVerts[1].y - center.y;
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v2.y = mLeafVerts[2].y - center.y;
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if(FCMin3(v0.y, v1.y, v2.y)>extents.y) return FALSE;
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if(FCMax3(v0.y, v1.y, v2.y)<-extents.y) return FALSE;
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// same for Z
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v0.z = mLeafVerts[0].z - center.z;
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v1.z = mLeafVerts[1].z - center.z;
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v2.z = mLeafVerts[2].z - center.z;
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if(FCMin3(v0.z, v1.z, v2.z)>extents.z) return FALSE;
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if(FCMax3(v0.z, v1.z, v2.z)<-extents.z) return FALSE;
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#else
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float min,max;
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// Find min, max of the triangle in x-direction, and test for overlap in X
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FINDMINMAX(v0.x, v1.x, v2.x, min, max);
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if(min>extents.x || max<-extents.x) return FALSE;
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// Same for Y
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v0.y = mLeafVerts[0].y - center.y;
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v1.y = mLeafVerts[1].y - center.y;
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v2.y = mLeafVerts[2].y - center.y;
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FINDMINMAX(v0.y, v1.y, v2.y, min, max);
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if(min>extents.y || max<-extents.y) return FALSE;
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// Same for Z
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v0.z = mLeafVerts[0].z - center.z;
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v1.z = mLeafVerts[1].z - center.z;
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v2.z = mLeafVerts[2].z - center.z;
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FINDMINMAX(v0.z, v1.z, v2.z, min, max);
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if(min>extents.z || max<-extents.z) return FALSE;
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#endif
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// 2) Test if the box intersects the plane of the triangle
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// compute plane equation of triangle: normal*x+d=0
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// ### could be precomputed since we use the same leaf triangle several times
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const Point e0 = v1 - v0;
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const Point e1 = v2 - v1;
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const Point normal = e0 ^ e1;
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const float d = -normal|v0;
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if(!planeBoxOverlap(normal, d, extents)) return FALSE;
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// 3) "Class III" tests - here we always do full tests since the box is a primitive (not a BV)
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{
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IMPLEMENT_CLASS3_TESTS
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}
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return TRUE;
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}
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