+// hitlist.cxx -
+// Height Over Terrain and Assosciated Routines for FlightGear based Scenery
+// Written by Norman Vine, started 2000.
+
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "hitlist.hxx"
-
extern ssgBranch *terrain_branch;
-#if 0
-// check to see if the intersection point is
-// actually inside this face
-static bool pointInTriangle( sgdVec3 point, sgdVec3 tri[3] )
-{
- double xmin, xmax, ymin, ymax, zmin, zmax;
-
- // punt if outside bouding cube
- if ( point[0] < (xmin = SG_MIN3 (tri[0][0], tri[1][0], tri[2][0])) ) {
- return false;
- } else if ( point[0] > (xmax = SG_MAX3 (tri[0][0], tri[1][0], tri[2][0])) )
- {
- return false;
- } else if ( point[1] < (ymin = SG_MIN3 (tri[0][1], tri[1][1], tri[2][1])) )
- {
- return false;
- } else if ( point[1] > (ymax = SG_MAX3 (tri[0][1], tri[1][1], tri[2][1])) )
- {
- return false;
- } else if ( point[2] < (zmin = SG_MIN3 (tri[0][2], tri[1][2], tri[2][2])) )
- {
- return false;
- } else if ( point[2] > (zmax = SG_MAX3 (tri[0][2], tri[1][2], tri[2][2])) )
- {
- return false;
- }
-
- // (finally) check to see if the intersection point is
- // actually inside this face
-
- //first, drop the smallest dimension so we only have to work
- //in 2d.
- double dx = xmax - xmin;
- double dy = ymax - ymin;
- double dz = zmax - zmin;
- double min_dim = SG_MIN3 (dx, dy, dz);
-
- //first, drop the smallest dimension so we only have to work
- //in 2d.
- double x1, y1, x2, y2, x3, y3, rx, ry;
- if ( fabs(min_dim-dx) <= SG_EPSILON ) {
- // x is the smallest dimension
- x1 = point[1];
- y1 = point[2];
- x2 = tri[0][1];
- y2 = tri[0][2];
- x3 = tri[1][1];
- y3 = tri[1][2];
- rx = tri[2][1];
- ry = tri[2][2];
- } else if ( fabs(min_dim-dy) <= SG_EPSILON ) {
- // y is the smallest dimension
- x1 = point[0];
- y1 = point[2];
- x2 = tri[0][0];
- y2 = tri[0][2];
- x3 = tri[1][0];
- y3 = tri[1][2];
- rx = tri[2][0];
- ry = tri[2][2];
- } else if ( fabs(min_dim-dz) <= SG_EPSILON ) {
- // z is the smallest dimension
- x1 = point[0];
- y1 = point[1];
- x2 = tri[0][0];
- y2 = tri[0][1];
- x3 = tri[1][0];
- y3 = tri[1][1];
- rx = tri[2][0];
- ry = tri[2][1];
- } else {
- // all dimensions are really small so lets call it close
- // enough and return a successful match
- return true;
- }
-
- // check if intersection point is on the same side of p1 <-> p2 as p3
- double tmp = (y2 - y3) / (x2 - x3);
- int side1 = SG_SIGN (tmp * (rx - x3) + y3 - ry);
- int side2 = SG_SIGN (tmp * (x1 - x3) + y3 - y1);
- if ( side1 != side2 ) {
- // printf("failed side 1 check\n");
- return false;
- }
-
- // check if intersection point is on correct side of p2 <-> p3 as p1
- tmp = (y3 - ry) / (x3 - rx);
- side1 = SG_SIGN (tmp * (x2 - rx) + ry - y2);
- side2 = SG_SIGN (tmp * (x1 - rx) + ry - y1);
- if ( side1 != side2 ) {
- // printf("failed side 2 check\n");
- return false;
- }
-
- // check if intersection point is on correct side of p1 <-> p3 as p2
- tmp = (y2 - ry) / (x2 - rx);
- side1 = SG_SIGN (tmp * (x3 - rx) + ry - y3);
- side2 = SG_SIGN (tmp * (x1 - rx) + ry - y1);
- if ( side1 != side2 ) {
- // printf("failed side 3 check\n");
- return false;
- }
-
- return true;
-}
-
static int sgdIsectInfLinePlane( sgdVec3 dst, const sgdVec3 l_org,
const sgdVec3 l_vec, const sgdVec4 plane )
{
}
-static void sgdXformPnt3 ( sgdVec3 dst, const sgVec3 src, const sgdMat4 mat )
-{
- SGDfloat t0 = src[ 0 ] ;
- SGDfloat t1 = src[ 1 ] ;
- SGDfloat t2 = src[ 2 ] ;
-
- dst[0] = ( t0 * mat[ 0 ][ 0 ] +
- t1 * mat[ 1 ][ 0 ] +
- t2 * mat[ 2 ][ 0 ] +
- mat[ 3 ][ 0 ] ) ;
-
- dst[1] = ( t0 * mat[ 0 ][ 1 ] +
- t1 * mat[ 1 ][ 1 ] +
- t2 * mat[ 2 ][ 1 ] +
- mat[ 3 ][ 1 ] ) ;
-
- dst[2] = ( t0 * mat[ 0 ][ 2 ] +
- t1 * mat[ 1 ][ 2 ] +
- t2 * mat[ 2 ][ 2 ] +
- mat[ 3 ][ 2 ] ) ;
-}
-#endif // 0
-
-
-/*
- Find the intersection of an infinite line with a plane
- (the line being defined by a point and direction).
-
- Norman Vine -- nhv@yahoo.com (with hacks by Steve)
-*/
-
-int sgdIsectInfLinePlane( sgdVec3 dst, sgdVec3 l_org,
- sgdVec3 l_vec, sgdVec4 plane )
-{
- SGDfloat tmp = sgdScalarProductVec3 ( l_vec, plane ) ;
-
- /* Is line parallel to plane? */
-
- if ( sgdAbs ( tmp ) < DBL_EPSILON )
- return FALSE ;
-
- sgdScaleVec3 ( dst, l_vec, -( sgdScalarProductVec3 ( l_org, plane )
- + plane[3] ) / tmp ) ;
- sgdAddVec3 ( dst, l_org ) ;
-
- return TRUE ;
-}
-
-
/*
* Given a point and a triangle lying on the same plane
* check to see if the point is inside the triangle
*/
-bool sgdPointInTriangle( sgdVec3 point, sgdVec3 tri[3] )
+static bool sgdPointInTriangle( sgdVec3 point, sgdVec3 tri[3] )
{
sgdVec3 dif;
if( (point[2] < min) || (point[2] > max) )
return false;
dif[2] = max - min;
-
+
// drop the smallest dimension so we only have to work in 2d.
SGDfloat min_dim = SG_MIN3 (dif[0], dif[1], dif[2]);
SGDfloat x1, y1, x2, y2, x3, y3, rx, ry;
}
+inline static int isZeroAreaTri( sgdVec3 tri[3] )
+{
+ return( sgdEqualVec3(tri[0], tri[1]) ||
+ sgdEqualVec3(tri[1], tri[2]) ||
+ sgdEqualVec3(tri[2], tri[0]) );
+}
+
+/*
+ * Given a point and a triangle lying on the same plane
+ * check to see if the point is inside the triangle
+ */
+
+#if 0
+static bool PointInTri( sgdVec3 P, sgdVec3 V[3] )
+{
+ sgdVec3 X,W1,W2;
+ sgdSubVec3(X,P,V[0]);
+ sgdSubVec3(W1,V[1],V[2]);
+ sgdSubVec3(W2,V[2],V[0]);
+
+ sgdVec3 C;
+ sgdVectorProductVec3(C, W1, W2);
+
+ double d = sgdScalarProductVec3(X,C);
+
+ // Test not needed if you KNOW point is on plane of triangle
+ // and triangle is not degenerate
+ if( d > -FLT_EPSILON && d < FLT_EPSILON )
+ return false;
+
+ double u11 = sgdScalarProductVec3(W1,W1);
+ double u22 = sgdScalarProductVec3(W2,W2);
+ double u12 = sgdScalarProductVec3(W1,W2);
+
+ double y1 = sgdScalarProductVec3(X,W1);
+ double y2 = sgdScalarProductVec3(X,W2);
+ double z1 = (y1*u22 - y2*u12)/d;
+
+ if( z1>0 || z1>1 )
+ return false;
+
+ double z2 = (y2*u11 - y1*u12)/d;
+
+ if( z2>0 || z2>1 )
+ return false;
+
+ return true;
+}
+#endif
+
/*
Find the intersection of an infinite line with a leaf
the line being defined by a point and direction.
Returns:
true if intersection found
false otherwise
+
+ !!! WARNING !!!
+ If you need an exhaustive list of hitpoints YOU MUST use
+ the generic version of this function as the specialized
+ versions will do an early out of expensive tests if the point
+ can not be the closest one found
+ !!! WARNING !!!
*/
int FGHitList::IntersectLeaf( ssgLeaf *leaf, sgdMat4 m,
- sgdVec3 orig, sgdVec3 dir )
+ sgdVec3 orig, sgdVec3 dir )
{
int num_hits = 0;
- for ( int i = 0; i < leaf->getNumTriangles(); ++i ) {
+ int i = 0;
+
+ for ( ; i < leaf->getNumTriangles(); ++i ) {
short i1, i2, i3;
leaf->getTriangle( i, &i1, &i2, &i3 );
- sgdVec3 tri[3];
- sgdSetVec3( tri[0], leaf->getVertex( i1 ) );
- sgdSetVec3( tri[1], leaf->getVertex( i2 ) );
- sgdSetVec3( tri[2], leaf->getVertex( i3 ) );
+ sgdVec3 tri[3];
+ sgdSetVec3( tri[0], leaf->getVertex( i1 ) );
+ sgdSetVec3( tri[1], leaf->getVertex( i2 ) );
+ sgdSetVec3( tri[2], leaf->getVertex( i3 ) );
+
+ // avoid division by zero when two points are the same
+ if( isZeroAreaTri( tri ) )
+ continue;
+
+ sgdVec4 plane;
+ sgdMakePlane( plane, tri[0], tri[1], tri[2] );
+
+ sgdVec3 point;
+ if( sgdIsectInfLinePlane( point, orig, dir, plane ) ) {
+ if( sgdPointInTriangle( point, tri ) ) {
+ // transform point into passed into desired coordinate frame
+ sgdXformPnt3( point, point, m );
+ add(leaf,i,point,plane);
+ num_hits++;
+ }
+ }
+ }
+ return num_hits;
+}
+
+
+//=================
+int FGHitList::IntersectPolyOrFanLeaf( ssgLeaf *leaf, sgdMat4 m,
+ sgdVec3 orig, sgdVec3 dir )
+{
+ double tmp_dist;
+
+ // number of hits but there could be more that
+ // were not found because of short circut switch !
+ // so you may want to use the unspecialized IntersectLeaf()
+ int num_hits = 0;
+
+ int ntri = leaf->getNumTriangles();
+ for ( int n = 0; n < ntri; ++n ) {
+ sgdVec3 tri[3];
+
+ if ( !n ) {
+ sgdSetVec3( tri[0], leaf->getVertex( short(0) ) );
+ sgdSetVec3( tri[1], leaf->getVertex( short(1) ) );
+ sgdSetVec3( tri[2], leaf->getVertex( short(2) ) );
+ } else {
+ sgdCopyVec3( tri[1], tri[2] );
+ sgdSetVec3( tri[2], leaf->getVertex( short(n+2) ) );
+ }
+
+ if( isZeroAreaTri( tri ) )
+ continue;
+
+ sgdVec4 plane;
+ sgdMakePlane( plane, tri[0], tri[1], tri[2] );
+
+ sgdVec3 point;
+
+ //inlined IsectInfLinePlane( point dst, orig, dir, plane )
+ {
+ SGDfloat tmp = sgdScalarProductVec3 ( dir, plane ) ;
+
+ /* Is line parallel to plane? */
+ if ( sgdAbs ( tmp ) < FLT_EPSILON /*DBL_EPSILON*/ )
+ continue ;
+
+ sgdScaleVec3 ( point, dir,
+ -( sgdScalarProductVec3 ( orig, plane ) + plane[3] )
+ / tmp ) ;
+
+ sgdAddVec3 ( point, orig ) ;
+ } // end of inlined intersection routine
+
+ // short circut if this point is further away then a previous hit
+ tmp_dist = sgdScalarProductVec3(point,point);
+ if( tmp_dist > test_dist )
+ continue;
+
+ if( sgdPointInTriangle( point, tri ) ) {
+ // transform point into passed coordinate frame
+ sgdXformPnt3( point, point, m );
+ add(leaf,n,point,plane);
+ test_dist = tmp_dist;
+ num_hits++;
+ }
+ }
+ return num_hits;
+}
+
+
+//===============
+
+int FGHitList::IntersectTriLeaf( ssgLeaf *leaf, sgdMat4 m,
+ sgdVec3 orig, sgdVec3 dir )
+{
+ double tmp_dist;
- //avoid division by zero when two points are the same
- if ( sgdEqualVec3(tri[0], tri[1]) ||
- sgdEqualVec3(tri[1], tri[2]) ||
- sgdEqualVec3(tri[2], tri[0]) ) {
- continue;
- }
+ // number of hits but there could be more that
+ // were not found because of short circut switch !
+ // so you may want to use the unspecialized IntersectLeaf()
+ int num_hits = 0;
+
+ int ntri = leaf->getNumTriangles();
+ for ( int n = 0; n < ntri; ++n ) {
+ sgdVec3 tri[3];
+ sgdSetVec3( tri[0], leaf->getVertex( short(n*3) ) );
+ sgdSetVec3( tri[1], leaf->getVertex( short(n*3+1) ) );
+ sgdSetVec3( tri[2], leaf->getVertex( short(n*3+2) ) );
+
+ // avoid division by zero when two points are the same
+ if( isZeroAreaTri( tri ) )
+ continue;
sgdVec4 plane;
sgdMakePlane( plane, tri[0], tri[1], tri[2] );
- sgdVec3 point;
-
- //inlined IsectInfLinePlane( point dst, orig, dir, plane )
- SGDfloat tmp = sgdScalarProductVec3 ( dir, plane ) ;
-
- /* Is line parallel to plane? */
- if ( sgdAbs ( tmp ) < DBL_EPSILON )
- continue ;
+ sgdVec3 point;
+ //inlined IsectInfLinePlane( point dst, orig, dir, plane )
+ {
+ SGDfloat tmp = sgdScalarProductVec3 ( dir, plane ) ;
+
+ /* Is line parallel to plane? */
+ if ( sgdAbs ( tmp ) < FLT_EPSILON /*DBL_EPSILON*/ )
+ continue ;
+
+ sgdScaleVec3 ( point, dir,
+ -( sgdScalarProductVec3 ( orig, plane ) + plane[3] )
+ / tmp ) ;
+
+ sgdAddVec3 ( point, orig ) ;
+ } // end of inlined intersection routine
+
+ // short circut if this point is further away then a previous hit
+ tmp_dist = sgdScalarProductVec3(point,point);
+ if( tmp_dist > test_dist )
+ continue;
+
+ if( sgdPointInTriangle( point, tri ) ) {
+ // transform point into passed coordinate frame
+ sgdXformPnt3( point, point, m );
+ add(leaf,n,point,plane);
+ test_dist = tmp_dist;
+ num_hits++;
+ }
+ }
+ return num_hits;
+}
+
+//============================
- sgdScaleVec3 ( point, dir,
- -( sgdScalarProductVec3 ( orig, plane ) + plane[3] )
- / tmp ) ;
+int FGHitList::IntersectStripLeaf( ssgLeaf *leaf, sgdMat4 m,
+ sgdVec3 orig, sgdVec3 dir )
+{
+ double tmp_dist;
+
+ // number of hits but there could be more that
+ // were not found because of short circut switch !
+ // so you may want to use the unspecialized IntersectLeaf()
+ int num_hits = 0;
+
+ int ntri = leaf->getNumTriangles();
+ for ( int n = 0; n < ntri; ++n ) {
+ sgdVec3 tri[3];
+
+ if ( !n ) {
+ sgdSetVec3( tri[0], leaf->getVertex( short(0) ) );
+ sgdSetVec3( tri[1], leaf->getVertex( short(1) ) );
+ sgdSetVec3( tri[2], leaf->getVertex( short(2) ) );
+ } else {
+ if ( n & 1 ) {
+ sgdSetVec3( tri[0], leaf->getVertex( short(n+2) ) );
+ sgdCopyVec3( tri[1], tri[2] );
+ sgdCopyVec3( tri[2], tri[1] );
+
+ } else {
+ sgdCopyVec3( tri[0], tri[1] );
+ sgdCopyVec3( tri[1], tri[2] );
+ sgdSetVec3( tri[2], leaf->getVertex( short(n+2) ) );
+ }
+ }
- sgdAddVec3 ( point, orig ) ;
- // end of inlined intersection
-#if 0
- if( pointInTriangle( point, tri ) ) {
- add(leaf,i,point,plane);
- num_hits++;
- }
-#endif // 0
- if( sgdPointInTriangle( point, tri ) ) {
- // transform point into passed into desired coordinate frame
- sgdXformPnt3( point, point, m );
- add(leaf,i,point,plane);
- num_hits++;
- }
+ if( isZeroAreaTri( tri ) )
+ continue;
+
+ sgdVec4 plane;
+ sgdMakePlane( plane, tri[0], tri[1], tri[2] );
+
+ sgdVec3 point;
+
+ //inlined IsectInfLinePlane( point dst, orig, dir, plane )
+ {
+ SGDfloat tmp = sgdScalarProductVec3 ( dir, plane ) ;
+
+ /* Is line parallel to plane? */
+ if ( sgdAbs ( tmp ) < FLT_EPSILON /*DBL_EPSILON*/ )
+ continue ;
+
+ sgdScaleVec3 ( point, dir,
+ -( sgdScalarProductVec3 ( orig, plane ) + plane[3] )
+ / tmp ) ;
+
+ sgdAddVec3 ( point, orig ) ;
+ } // end of inlined intersection routine
+
+ // short circut if this point is further away then a previous hit
+ tmp_dist = sgdScalarProductVec3(point,point);
+ if( tmp_dist > test_dist )
+ continue;
+
+ if( sgdPointInTriangle( point, tri ) ) {
+ // transform point into passed coordinate frame
+ sgdXformPnt3( point, point, m );
+ add(leaf,n,point,plane);
+ test_dist = tmp_dist;
+ num_hits++;
+ }
}
return num_hits;
}
+// ======================
+
+int FGHitList::IntersectQuadsLeaf( ssgLeaf *leaf, sgdMat4 m,
+ sgdVec3 orig, sgdVec3 dir )
+{
+ double tmp_dist;
+
+ // number of hits but there could be more that
+ // were not found because of short circut switch !
+ // so you may want to use the unspecialized IntersectLeaf()
+ int num_hits = 0;
+
+ int ntri = leaf->getNumTriangles();
+ for ( int n = 0; n < ntri; ++n ) {
+ sgdVec3 tri[3];
+
+ sgdSetVec3( tri[0], leaf->getVertex( short(n*2) ) );
+ sgdSetVec3( tri[1], leaf->getVertex( short(n*2+1) ) );
+ sgdSetVec3( tri[2], leaf->getVertex( short(n*2 + 2 - (n&1)*4) ) );
+
+ if( isZeroAreaTri( tri ) )
+ continue;
+
+ sgdVec4 plane;
+ sgdMakePlane( plane, tri[0], tri[1], tri[2] );
+
+ sgdVec3 point;
+
+ //inlined IsectInfLinePlane( point dst, orig, dir, plane )
+ {
+ SGDfloat tmp = sgdScalarProductVec3 ( dir, plane ) ;
+
+ /* Is line parallel to plane? */
+ if ( sgdAbs ( tmp ) < FLT_EPSILON /*DBL_EPSILON*/ )
+ continue ;
+
+ sgdScaleVec3 ( point, dir,
+ -( sgdScalarProductVec3 ( orig, plane ) + plane[3] )
+ / tmp ) ;
+
+ sgdAddVec3 ( point, orig ) ;
+ } // end of inlined intersection routine
+
+ // short circut if this point is further away then a previous hit
+ tmp_dist = sgdScalarProductVec3(point,point);
+ if( tmp_dist > test_dist )
+ continue;
+
+ if( sgdPointInTriangle( point, tri ) ) {
+ // transform point into passed coordinate frame
+ sgdXformPnt3( point, point, m );
+ add(leaf,n,point,plane);
+ test_dist = tmp_dist;
+ num_hits++;
+ }
+ }
+ return num_hits;
+}
+
+
+
+// Need these because of mixed matrix types
+static void sgMultMat4(sgdMat4 dst, sgdMat4 m1, sgMat4 m2)
+{
+ for ( int j = 0 ; j < 4 ; j++ ) {
+ dst[0][j] = m2[0][0] * m1[0][j] +
+ m2[0][1] * m1[1][j] +
+ m2[0][2] * m1[2][j] +
+ m2[0][3] * m1[3][j] ;
+
+ dst[1][j] = m2[1][0] * m1[0][j] +
+ m2[1][1] * m1[1][j] +
+ m2[1][2] * m1[2][j] +
+ m2[1][3] * m1[3][j] ;
+
+ dst[2][j] = m2[2][0] * m1[0][j] +
+ m2[2][1] * m1[1][j] +
+ m2[2][2] * m1[2][j] +
+ m2[2][3] * m1[3][j] ;
+
+ dst[3][j] = m2[3][0] * m1[0][j] +
+ m2[3][1] * m1[1][j] +
+ m2[3][2] * m1[2][j] +
+ m2[3][3] * m1[3][j] ;
+ }
+}
+
+/*
+ *
+ */
void FGHitList::IntersectBranch( ssgBranch *branch, sgdMat4 m,
sgdVec3 orig, sgdVec3 dir )
{
- sgSphere *bsphere;
-
/* the lookat vector and matrix in branch's coordinate frame
- * but we won't determine these unless needed to,
+ * but we won't determine these unless needed,
* This 'lazy evaluation' is a result of profiling data */
- sgdVec3 _orig, _dir;
- sgdMat4 _m;
+ sgdVec3 orig_leaf, dir_leaf;
+ sgdMat4 m_leaf;
+
// 'lazy evaluation' flag
int first_time = 1;
kid = branch->getNextKid() )
{
if ( kid->getTraversalMask() & SSGTRAV_HOT ) {
- bsphere = kid->getBSphere();
- sgdVec3 center;
- sgdSetVec3( center,
- bsphere->getCenter()[0],
- bsphere->getCenter()[1],
- bsphere->getCenter()[2] );
- sgdXformPnt3( center, m ) ;
-
- // sgdClosestPointToLineDistSquared( center, orig, dir )
- // inlined here because because of profiling results
- sgdVec3 u, u1, v;
- sgdSubVec3(u, center, orig);
- sgdScaleVec3( u1, dir, sgdScalarProductVec3(u,dir)
- / sgdScalarProductVec3(dir,dir) );
- sgdSubVec3(v, u, u1);
-
- // doubles because of possible overflow
+ sgdVec3 center;
+ sgdSetVec3( center,
+ kid->getBSphere()->getCenter()[0],
+ kid->getBSphere()->getCenter()[1],
+ kid->getBSphere()->getCenter()[2] );
+ sgdXformPnt3( center, m ) ;
+
+ // sgdClosestPointToLineDistSquared( center, orig, dir )
+ // inlined here because because of profiling results
+ sgdVec3 u, u1, v;
+ sgdSubVec3(u, center, orig);
+ sgdScaleVec3( u1, dir, sgdScalarProductVec3(u,dir)
+ / sgdScalarProductVec3(dir,dir) );
+ sgdSubVec3(v, u, u1);
+
+ // doubles because of possible overflow
#define SQUARE(x) (x*x)
- if( sgdScalarProductVec3(v, v)
- < SQUARE( double(bsphere->getRadius()) ) )
- {
- // possible intersections
- if ( kid->isAKindOf ( ssgTypeBranch() ) ) {
- sgdMat4 m_new;
- sgdCopyMat4(m_new, m);
- if ( kid->isA( ssgTypeTransform() ) ) {
- sgMat4 fxform;
- ((ssgTransform *)kid)->getTransform( fxform );
- sgdMat4 xform;
- sgdSetMat4( xform, fxform );
- sgdPreMultMat4( m_new, xform );
- }
- IntersectBranch( (ssgBranch *)kid, m_new, orig, dir );
- } else if ( kid->isAKindOf( ssgTypeLeaf() ) ) {
- if( first_time) {
- // OK we need these
- sgdTransposeNegateMat4( _m, m);
- sgdXformPnt3( _orig, orig, _m );
- sgdXformPnt3( _dir, dir, _m );
- first_time = 0;
- }
- IntersectLeaf( (ssgLeaf *)kid, m, _orig, _dir );
- }
- } else {
- // end of the line for this branch
- }
- } else {
- // branch requested not to be traversed
- }
+ if( sgdScalarProductVec3(v, v)
+ < SQUARE( double(kid->getBSphere()->getRadius()) ) )
+ {
+ // possible intersections
+ if ( kid->isAKindOf ( ssgTypeBranch() ) ) {
+ sgdMat4 m_new;
+ if ( kid->isA( ssgTypeTransform() ) )
+ {
+ sgMat4 fxform;
+ ((ssgTransform *)kid)->getTransform( fxform );
+ sgMultMat4(m_new, m, fxform);
+ } else {
+ sgdCopyMat4(m_new, m);
+ }
+ IntersectBranch( (ssgBranch *)kid, m_new, orig, dir );
+ } else if ( kid->isAKindOf( ssgTypeLeaf() ) ) {
+ if ( first_time ) {
+ // OK we need these
+ sgdTransposeNegateMat4( m_leaf, m);
+ sgdXformPnt3( orig_leaf, orig, m_leaf );
+ sgdXformPnt3( dir_leaf, dir, m_leaf );
+ first_time = 0;
+ }
+
+ GLenum primType = ((ssgLeaf *)kid)->getPrimitiveType();
+
+ switch ( primType ) {
+ case GL_POLYGON :
+ case GL_TRIANGLE_FAN :
+ IntersectPolyOrFanLeaf( (ssgLeaf *)kid, m,
+ orig_leaf, dir_leaf );
+ break;
+ case GL_TRIANGLES :
+ IntersectTriLeaf( (ssgLeaf *)kid, m,
+ orig_leaf, dir_leaf );
+ break;
+ case GL_TRIANGLE_STRIP :
+ case GL_QUAD_STRIP :
+ IntersectStripLeaf( (ssgLeaf *)kid, m,
+ orig_leaf, dir_leaf );
+ break;
+ case GL_QUADS :
+ IntersectQuadsLeaf( (ssgLeaf *)kid, m,
+ orig_leaf, dir_leaf );
+ break;
+ default:
+ IntersectLeaf( (ssgLeaf *)kid, m,
+ orig_leaf, dir_leaf );
+ }
+ }
+ } else {
+ // end of the line for this branch
+ }
+ } else {
+ // branch requested not to be traversed
+ }
}
}
+void ssgGetEntityTransform(ssgEntity *entity, sgMat4 m )
+{
+ /*
+ Walk backwards up the tree, transforming the
+ vertex by all the matrices along the way.
+
+ Upwards recursion hurts my head.
+ */
+
+ sgMat4 mat ;
+
+ /*
+ If this node has a parent - get the composite
+ matrix for the parent.
+ */
+
+ if ( entity->getNumParents() > 0 )
+ ssgGetEntityTransform ( entity->getParent(0), mat ) ;
+ else
+ sgMakeIdentMat4 ( mat ) ;
+
+ /*
+ If this node has a transform - then concatenate it.
+ */
+
+ if ( entity -> isAKindOf ( ssgTypeTransform () ) ) {
+ sgMat4 this_mat ;
+ ((ssgTransform *) entity) -> getTransform ( this_mat ) ;
+ sgPostMultMat4 ( mat, this_mat ) ;
+ }
-// This expects the inital m to the identity transform
+ sgCopyMat4 ( m, mat ) ;
+}
+#if 0
+// previously used method
+// This expects the inital m to be the identity transform
void ssgGetEntityTransform(ssgEntity *branch, sgMat4 m )
{
for ( ssgEntity *parent = branch->getParent(0);
- parent != NULL;
- parent = parent->getNextParent() )
+ parent != NULL;
+ parent = parent->getParent(0) )
{
- // recurse till we are at the scene root
- // then just unwinding the stack should
- // give us our cumulative transform :-) NHV
- ssgGetEntityTransform( parent, m );
- if ( parent->isA( ssgTypeTransform() ) ) {
- sgMat4 xform;
- ((ssgTransform *)parent)->getTransform( xform );
- sgPreMultMat4( m, xform );
- }
+ // recurse till we are at the scene root
+ // then just unwinding the stack should
+ // give us our cumulative transform :-) NHV
+ ssgGetEntityTransform( parent, m );
+ if ( parent->isA( ssgTypeTransform() ) ) {
+ sgMat4 xform;
+ ((ssgTransform *)parent)->getTransform( xform );
+ sgPreMultMat4( m, xform );
+ }
}
}
-
+#endif // 0
// return the passed entitity's bsphere's center point radius and
// fully formed current model matrix for entity
void ssgGetCurrentBSphere( ssgEntity *entity, sgVec3 center,
- float *radius, sgMat4 m )
+ float *radius, sgMat4 m )
{
sgSphere *bsphere = entity->getBSphere();
*radius = (double)bsphere->getRadius();
}
-void FGHitList::IntersectCachedLeaf( sgdMat4 m,
- sgdVec3 orig, sgdVec3 dir)
-{
- if ( last_hit() ) {
- float radius;
- sgVec3 fcenter;
- sgMat4 fxform;
- // ssgEntity *ent = last_hit();
- ssgGetCurrentBSphere( last_hit(), fcenter, &radius, fxform );
- sgdMat4 m;
- sgdVec3 center;
- sgdSetMat4( m, fxform );
- sgdXformPnt3( center, m );
-
- if ( sgdClosestPointToLineDistSquared( center, orig, dir ) <
- double(radius*radius) )
- {
- IntersectLeaf( (ssgLeaf *)last_hit(), m, orig, dir );
- }
- }
-}
-
-
void FGHitList::Intersect( ssgBranch *scene, sgdVec3 orig, sgdVec3 dir ) {
sgdMat4 m;
-
-// #define USE_CACHED_HIT
-
-#ifdef USE_CACHED_HIT
- // This optimization gives a slight speedup
- // but it precludes using the hitlist for dynamic
- // objects NHV
- init();
- if( last_hit() ) {
- sgdMakeIdentMat4 ( m ) ;
- IntersectCachedLeaf(m, orig, dir);
- }
- if( ! num_hits() ) {
-#endif
-
- clear();
- sgdMakeIdentMat4 ( m ) ;
- IntersectBranch( scene, m, orig, dir);
-
-#ifdef USE_CACHED_HIT
- }
-#endif
+ clear();
+ sgdMakeIdentMat4 ( m ) ;
+ IntersectBranch( scene, m, orig, dir);
}
}
-// Determine scenery altitude via ssg. Normally this just happens
-// when we render the scene, but we'd also like to be able to do this
-// explicitely. lat & lon are in radians. view_pos in current world
-// coordinate translated near (0,0,0) (in meters.) Returns result in
-// meters.
+/*
+ * This method is faster
+ */
+
+void FGHitList::Intersect( ssgBranch *scene, sgdMat4 m, sgdVec3 orig,
+ sgdVec3 dir )
+{
+ clear();
+ IntersectBranch( scene, m, orig, dir);
+}
+
+
+// Determine scenery altitude via ssg.
+// returned results are in meters
bool fgCurrentElev( sgdVec3 abs_view_pos, sgdVec3 scenery_center,
FGHitList *hit_list,
double *terrain_elev, double *radius, double *normal)
sgdVec3 orig, dir;
sgdCopyVec3(orig, view_pos );
sgdCopyVec3(dir, abs_view_pos );
+ // sgdNormalizeVec3(dir);
+ // !! why is terrain not globals->get_terrain()
hit_list->Intersect( terrain_branch, orig, dir );
int this_hit=0;
Point3D geoc;
double result = -9999;
Point3D sc(scenery_center[0], scenery_center[1], scenery_center[2]) ;
-
+
+ // cout << "hits = ";
int hitcount = hit_list->num_hits();
for ( int i = 0; i < hitcount; ++i ) {
geoc = sgCartToPolar3d( sc + hit_list->get_point(i) );
double lat_geod, alt, sea_level_r;
sgGeocToGeod(geoc.lat(), geoc.radius(), &lat_geod,
&alt, &sea_level_r);
+ // cout << alt << " ";
if ( alt > result && alt < 10000 ) {
result = alt;
this_hit = i;
}
}
+ // cout << endl;
if ( result > -9000 ) {
*terrain_elev = result;
// cout << "NED: " << tmp[0] << " " << tmp[1] << " " << tmp[2] << endl;
return true;
} else {
- SG_LOG( SG_TERRAIN, SG_INFO, "no terrain intersection" );
- *terrain_elev = 0.0;
- float *up = globals->get_current_view()->get_world_up();
- sgdSetVec3(normal, up[0], up[1], up[2]);
- return false;
+ SG_LOG( SG_TERRAIN, SG_INFO, "no terrain intersection" );
+ *terrain_elev = 0.0;
+ float *up = globals->get_current_view()->get_world_up();
+ sgdSetVec3(normal, up[0], up[1], up[2]);
+ return false;
}
}
+
+
+// Determine scenery altitude via ssg.
+// returned results are in meters
+bool fgCurrentElev( sgdVec3 abs_view_pos, sgdVec3 scenery_center,
+ ssgTransform *terra_transform,
+ FGHitList *hit_list,
+ double *terrain_elev, double *radius, double *normal)
+{
+#ifndef FAST_HITLIST__TEST
+ return fgCurrentElev( abs_view_pos, scenery_center, hit_list,
+ terrain_elev,radius,normal);
+#else
+ sgdVec3 view_pos;
+ sgdSubVec3( view_pos, abs_view_pos, scenery_center );
+
+ sgdVec3 orig, dir;
+ sgdCopyVec3(orig, view_pos );
+
+ sgdCopyVec3(dir, abs_view_pos );
+ sgdNormalizeVec3(dir);
+
+ sgMat4 fxform;
+ sgMakeIdentMat4 ( fxform ) ;
+ ssgGetEntityTransform( terra_transform, fxform );
+
+ sgdMat4 xform;
+ sgdSetMat4(xform,fxform);
+ hit_list->Intersect( terra_transform, xform, orig, dir );
+
+ int this_hit=0;
+ Point3D geoc;
+ double result = -9999;
+ Point3D sc(scenery_center[0], scenery_center[1], scenery_center[2]) ;
+
+ int hitcount = hit_list->num_hits();
+ for ( int i = 0; i < hitcount; ++i ) {
+ geoc = sgCartToPolar3d( sc + hit_list->get_point(i) );
+ double lat_geod, alt, sea_level_r;
+ sgGeocToGeod(geoc.lat(), geoc.radius(), &lat_geod,
+ &alt, &sea_level_r);
+ if ( alt > result && alt < 20000 ) {
+ result = alt;
+ this_hit = i;
+ }
+ }
+
+ if ( result > -9000 ) {
+ *terrain_elev = result;
+ *radius = geoc.radius();
+ sgVec3 tmp;
+ sgSetVec3(tmp, hit_list->get_normal(this_hit));
+ // cout << "cur_normal: " << tmp[0] << " " << tmp[1] << " "
+ // << tmp[2] << endl;
+ /* ssgState *IntersectedLeafState =
+ ((ssgLeaf*)hit_list->get_entity(this_hit))->getState(); */
+ CurrentNormalInLocalPlane(tmp, tmp);
+ sgdSetVec3( normal, tmp );
+ // cout << "NED: " << tmp[0] << " " << tmp[1] << " " << tmp[2] << endl;
+ return true;
+ } else {
+ SG_LOG( SG_TERRAIN, SG_DEBUG, "DOING FULL TERRAIN INTERSECTION" );
+ return fgCurrentElev( abs_view_pos, scenery_center, hit_list,
+ terrain_elev,radius,normal);
+ }
+#endif // !FAST_HITLIST__TEST
+}
+
projects / flightgear.git / commitdiff