X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FScenery%2Fhitlist.cxx;h=310d06190b89e44569341c75834e6453cb7a9504;hb=68f248879cb15562c7b026445f83caf8f2842ae9;hp=594ffc36b0cecb505aaabd462657d62b63127ccc;hpb=ca6067cbc076f1066873cff923309920002af365;p=flightgear.git diff --git a/src/Scenery/hitlist.cxx b/src/Scenery/hitlist.cxx index 594ffc36b..310d06190 100644 --- a/src/Scenery/hitlist.cxx +++ b/src/Scenery/hitlist.cxx @@ -9,11 +9,15 @@ #include #include +#include +#include + #include #include #include #include #include +#include #include
#include
@@ -21,17 +25,79 @@ #include "hitlist.hxx" -// forward declaration of our helper/convenience functions -static void sgMultMat4(sgdMat4 dst, sgdMat4 m1, sgMat4 m2); -static void ssgGetEntityTransform(ssgEntity *entity, sgMat4 m ); -static void ssgGetCurrentBSphere( ssgEntity *entity, sgVec3 center, float *radius, sgMat4 m ); +// Specialized version of sgMultMat4 needed because of mixed matrix +// types +static inline 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] ; + } +} + + +/* + * Walk backwards up the tree, transforming the vertex by all the + * matrices along the way. + * + * Upwards recursion hurts my head. + */ +static void ssgGetEntityTransform(ssgEntity *entity, sgMat4 m ) { + 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 ) ; + } + + sgCopyMat4 ( m, mat ) ; +} + + +// return the passed entitity's bsphere's center point radius and +// fully formed current model matrix for entity +static inline void ssgGetCurrentBSphere( ssgEntity *entity, sgVec3 center, + float *radius, sgMat4 m ) +{ + sgSphere *bsphere = entity->getBSphere(); + *radius = (double)bsphere->getRadius(); + sgCopyVec3( center, bsphere->getCenter() ); + sgMakeIdentMat4 ( m ) ; + ssgGetEntityTransform( entity, m ); +} -// ====================== -// This is same as PLib's sgdIsectInfLinePlane() -// and can be replaced by it after the next PLib release -static int fgdIsectInfLinePlane( sgdVec3 dst, const sgdVec3 l_org, - const sgdVec3 l_vec, const sgdVec4 plane ) +// This is same as PLib's sgdIsectInfLinePlane() and can be replaced +// by it after the next PLib release +static inline bool fgdIsectInfLinePlane( sgdVec3 dst, + const sgdVec3 l_org, + const sgdVec3 l_vec, + const sgdVec4 plane ) { SGDfloat tmp = sgdScalarProductVec3 ( l_vec, plane ) ; @@ -47,32 +113,34 @@ static int fgdIsectInfLinePlane( sgdVec3 dst, const sgdVec3 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 + * Given a point and a triangle lying on the same plane check to see + * if the point is inside the triangle + * + * This is same as PLib's sgdPointInTriangle() and can be replaced by + * it after the next PLib release */ -// This is same as PLib's sgdPointInTriangle() -// and can be replaced by it after the next PLib release -static bool fgdPointInTriangle( sgdVec3 point, sgdVec3 tri[3] ) +static inline bool fgdPointInTriangle( sgdVec3 point, sgdVec3 tri[3] ) { sgdVec3 dif; + // Some tolerance in meters we accept a point to be outside of the triangle + // and still return that it is inside. + SGDfloat eps = 1e-4; SGDfloat min, max; // punt if outside bouding cube SG_MIN_MAX3 ( min, max, tri[0][0], tri[1][0], tri[2][0] ); - if( (point[0] < min) || (point[0] > max) ) + if( (point[0] < min - eps) || (point[0] > max + eps) ) return false; dif[0] = max - min; SG_MIN_MAX3 ( min, max, tri[0][1], tri[1][1], tri[2][1] ); - if( (point[1] < min) || (point[1] > max) ) + if( (point[1] < min - eps) || (point[1] > max + eps) ) return false; dif[1] = max - min; SG_MIN_MAX3 ( min, max, tri[0][2], tri[1][2], tri[2][2] ); - if( (point[2] < min) || (point[2] > max) ) + if( (point[2] < min - eps) || (point[2] > max + eps) ) return false; dif[2] = max - min; @@ -116,27 +184,33 @@ static bool fgdPointInTriangle( sgdVec3 point, sgdVec3 tri[3] ) } // check if intersection point is on the same side of p1 <-> p2 as p3 - SGDfloat tmp = (y2 - y3) / (x2 - x3); - int side1 = SG_SIGN (tmp * (rx - x3) + y3 - ry); - int side2 = SG_SIGN (tmp * (x1 - x3) + y3 - y1); + SGDfloat tmp = (y2 - y3); + SGDfloat tmpn = (x2 - x3); + int side1 = SG_SIGN (tmp * (rx - x3) + (y3 - ry) * tmpn); + int side2 = SG_SIGN (tmp * (x1 - x3) + (y3 - y1) * tmpn + + side1 * eps * fabs(tmpn)); 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); + tmp = (y3 - ry); + tmpn = (x3 - rx); + side1 = SG_SIGN (tmp * (x2 - rx) + (ry - y2) * tmpn); + side2 = SG_SIGN (tmp * (x1 - rx) + (ry - y1) * tmpn + + side1 * eps * fabs(tmpn)); 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); + tmp = (y2 - ry); + tmpn = (x2 - rx); + side1 = SG_SIGN (tmp * (x3 - rx) + (ry - y3) * tmpn); + side2 = SG_SIGN (tmp * (x1 - rx) + (ry - y1) * tmpn + + side1 * eps * fabs(tmpn)); if ( side1 != side2 ) { // printf("failed side 3 check\n"); return false; @@ -145,26 +219,109 @@ static bool fgdPointInTriangle( sgdVec3 point, sgdVec3 tri[3] ) return true; } -// ====================== -inline static int isZeroAreaTri( sgdVec3 tri[3] ) +// Check if all three vertices are the same point (or close enough) +static inline int isZeroAreaTri( sgdVec3 tri[3] ) { return( sgdEqualVec3(tri[0], tri[1]) || sgdEqualVec3(tri[1], tri[2]) || sgdEqualVec3(tri[2], tri[0]) ); } + +// Constructor FGHitList::FGHitList() : - last(NULL), test_dist(DBL_MAX) + last(NULL), test_dist(DBL_MAX) { } + +// Destructor FGHitList::~FGHitList() {} +// http://www.cs.lth.se/home/Tomas_Akenine_Moller/raytri/raytri.c +// http://little3d.free.fr/ressources/jgt%20Fast,%20Minumum%20Storage%20Ray-Triangle%20Intersection.htm +// http://www.acm.org/jgt/papers/MollerTrumbore97/ + +/* Ray-Triangle Intersection Test Routines */ +/* Different optimizations of my and Ben Trumbore's */ +/* code from journals of graphics tools (JGT) */ +/* http://www.acm.org/jgt/ */ +/* by Tomas Moller, May 2000 */ + +/* code rewritten to do tests on the sign of the determinant */ +/* the division is at the end in the code */ +// cosmetics change by H.J : +// make u & v locals since we don't use them, use sg functions +static bool intersect_triangle(const double orig[3], const double dir[3], + const double vert0[3], const double vert1[3], const double vert2[3], + double *t) +{ + double u, v; + double edge1[3], edge2[3], tvec[3], pvec[3], qvec[3]; + + const SGDfloat eps = 1e-4; + + /* find vectors for two edges sharing vert0 */ + sgdSubVec3(edge1, vert1, vert0); + sgdSubVec3(edge2, vert2, vert0); + + /* begin calculating determinant - also used to calculate U parameter */ + sgdVectorProductVec3(pvec, dir, edge2); + + /* if determinant is near zero, ray lies in plane of triangle */ + double det = sgdScalarProductVec3(edge1, pvec); + + if (det > eps) + { + /* calculate distance from vert0 to ray origin */ + sgdSubVec3(tvec, orig, vert0); + + /* calculate U parameter and test bounds */ + u = sgdScalarProductVec3(tvec, pvec); + if (u < 0.0 || u > det) + return false; + + /* prepare to test V parameter */ + sgdVectorProductVec3(qvec, tvec, edge1); + + /* calculate V parameter and test bounds */ + v = sgdScalarProductVec3(dir, qvec); + if (v < 0.0 || u + v > det) + return false; + + } + else if(det < -eps) + { + /* calculate distance from vert0 to ray origin */ + sgdSubVec3(tvec, orig, vert0); + + /* calculate U parameter and test bounds */ + u = sgdScalarProductVec3(tvec, pvec); + if (u > 0.0 || u < det) + return false; + + /* prepare to test V parameter */ + sgdVectorProductVec3(qvec, tvec, edge1); + + /* calculate V parameter and test bounds */ + v = sgdScalarProductVec3(dir, qvec) ; + if (v > 0.0 || u + v < det) + return false; + } + else return false; /* ray is parallell to the plane of the triangle */ + + /* calculate t, ray intersects triangle */ + *t = sgdScalarProductVec3(edge2, qvec) / det; + + return true; +} + + /* -Find the intersection of an infinite line with a leaf -the line being defined by a point and direction. +Find the intersection of an infinite line with a leaf the line being +defined by a point and direction. Variables In: @@ -181,10 +338,11 @@ 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 + +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, @@ -201,7 +359,21 @@ int FGHitList::IntersectLeaf( ssgLeaf *leaf, sgdMat4 m, sgdSetVec3( tri[0], leaf->getVertex( i1 ) ); sgdSetVec3( tri[1], leaf->getVertex( i2 ) ); sgdSetVec3( tri[2], leaf->getVertex( i3 ) ); - +#if 1 + sgdFloat t; + if( intersect_triangle( orig, dir, tri[0], tri[1], tri[2], &t) ) { + sgdVec4 plane; + sgdMakePlane( plane, tri[0], tri[1], tri[2] ); + // t is the distance to the triangle plane + // so P = Orig + t*dir + sgdVec3 point; + sgdAddScaledVec3( point, orig, dir, t ); + sgdXformPnt3( point, point, m ); + sgdXformPnt4(plane,plane,m); + add(leaf,i,point,plane); + num_hits++; + } +#else if( isZeroAreaTri( tri ) ) continue; @@ -213,17 +385,18 @@ int FGHitList::IntersectLeaf( ssgLeaf *leaf, sgdMat4 m, if( fgdPointInTriangle( point, tri ) ) { // transform point into passed into desired coordinate frame sgdXformPnt3( point, point, m ); - sgdXformPnt4(plane,plane,m); + sgdXformPnt4(plane,plane,m); add(leaf,i,point,plane); num_hits++; } } +#endif } return num_hits; } -// ====================== +// Short circuit/slightly optimized version of the full IntersectLeaf() int FGHitList::IntersectLeaf( ssgLeaf *leaf, sgdMat4 m, sgdVec3 orig, sgdVec3 dir, GLenum primType ) @@ -279,7 +452,7 @@ int FGHitList::IntersectLeaf( ssgLeaf *leaf, sgdMat4 m, sgdCopyVec3( tri[0], tri[2] ); sgdSetVec3( tri[2], leaf->getVertex( short(n+2) ) ); } else { - sgdCopyVec3( tri[2], tri[1] ); + sgdCopyVec3( tri[1], tri[2] ); sgdSetVec3( tri[2], leaf->getVertex( short(n+2) ) ); } } @@ -337,18 +510,19 @@ int FGHitList::IntersectLeaf( ssgLeaf *leaf, sgdMat4 m, return num_hits; } -// ====================== + + inline static bool IN_RANGE( sgdVec3 v, double radius ) { return ( sgdScalarProductVec3(v, v) < (radius*radius) ); } -// ====================== + void FGHitList::IntersectBranch( ssgBranch *branch, sgdMat4 m, sgdVec3 orig, sgdVec3 dir ) { - /* the lookat vector and matrix in branch's coordinate frame - * but we won't determine these unless needed, - * This 'lazy evaluation' is a result of profiling data */ + /* the lookat vector and matrix in branch's coordinate frame but + * we won't determine these unless needed, This 'lazy evaluation' + * is a result of profiling data */ sgdVec3 orig_leaf, dir_leaf; sgdMat4 m_leaf; @@ -363,18 +537,18 @@ void FGHitList::IntersectBranch( ssgBranch *branch, sgdMat4 m, && !kid->getBSphere()->isEmpty() ) { sgdVec3 center; + const sgFloat *BSCenter = kid->getBSphere()->getCenter(); sgdSetVec3( center, - kid->getBSphere()->getCenter()[0], - kid->getBSphere()->getCenter()[1], - kid->getBSphere()->getCenter()[2] ); + BSCenter[0], + BSCenter[1], + BSCenter[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) ); + sgdScaleVec3( u1, dir, sgdScalarProductVec3(u,dir) ); sgdSubVec3(v, u, u1); // double because of possible overflow @@ -398,11 +572,13 @@ void FGHitList::IntersectBranch( ssgBranch *branch, sgdMat4 m, if ( first_time ) { sgdTransposeNegateMat4( m_leaf, m ); sgdXformPnt3( orig_leaf, orig, m_leaf ); - sgdXformPnt3( dir_leaf, dir, m_leaf ); + sgdXformVec3( dir_leaf, dir, m_leaf ); first_time = 0; } - GLenum primType = ((ssgLeaf *)kid)->getPrimitiveType(); - IntersectLeaf( (ssgLeaf *)kid, m, orig_leaf, dir_leaf, primType ); + // GLenum primType = ((ssgLeaf *)kid)->getPrimitiveType(); + // IntersectLeaf( (ssgLeaf *)kid, m, orig_leaf, dir_leaf, + // primType ); + IntersectLeaf( (ssgLeaf *)kid, m, orig_leaf, dir_leaf ); } } // Out of range } // branch not requested to be traversed @@ -410,8 +586,6 @@ void FGHitList::IntersectBranch( ssgBranch *branch, sgdMat4 m, } - -// ====================== // a temporary hack until we get everything rewritten with sgdVec3 static inline Point3D operator + (const Point3D& a, const sgdVec3 b) { @@ -419,7 +593,6 @@ static inline Point3D operator + (const Point3D& a, const sgdVec3 b) } -// ====================== void FGHitList::Intersect( ssgBranch *scene, sgdVec3 orig, sgdVec3 dir ) { sgdMat4 m; clear(); @@ -427,95 +600,26 @@ void FGHitList::Intersect( ssgBranch *scene, sgdVec3 orig, sgdVec3 dir ) { IntersectBranch( scene, m, orig, dir ); } -// ====================== + void FGHitList::Intersect( ssgBranch *scene, sgdMat4 m, sgdVec3 orig, sgdVec3 dir ) { clear(); IntersectBranch( scene, m, orig, dir ); } -// ====================== -// 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] ; - } -} - -// ====================== -static 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 ) ; - } - - sgCopyMat4 ( m, mat ) ; -} - -// ====================== -// return the passed entitity's bsphere's center point radius and -// fully formed current model matrix for entity -static void ssgGetCurrentBSphere( ssgEntity *entity, sgVec3 center, float *radius, sgMat4 m ) -{ - sgSphere *bsphere = entity->getBSphere(); - *radius = (double)bsphere->getRadius(); - sgCopyVec3( center, bsphere->getCenter() ); - sgMakeIdentMat4 ( m ) ; - ssgGetEntityTransform( entity, m ); -} - -// ====================== // Determine scenery altitude via ssg. // returned results are in meters +// static double hitlist1_time = 0.0; + bool fgCurrentElev( sgdVec3 abs_view_pos, double max_alt_m, sgdVec3 scenery_center, FGHitList *hit_list, double *terrain_elev, double *radius, double *normal) { + // SGTimeStamp start; start.stamp(); + + bool result; sgdVec3 view_pos; sgdSubVec3( view_pos, abs_view_pos, scenery_center ); @@ -523,33 +627,47 @@ bool fgCurrentElev( sgdVec3 abs_view_pos, double max_alt_m, sgdCopyVec3(orig, view_pos ); sgdCopyVec3(dir, abs_view_pos ); + sgdNormaliseVec3( dir ); hit_list->Intersect( globals->get_scenery()->get_terrain_branch(), orig, dir ); - int this_hit=0; + int this_hit = -1; + int max_hit = -1; Point3D geoc; - double result = -9999; + double hit_elev = -9999; + double max_elev = -9999; Point3D sc(scenery_center[0], scenery_center[1], scenery_center[2]) ; int hitcount = hit_list->num_hits(); // cout << "hits = " << hitcount << endl; 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); + // FIXME: sgCartToGeod is slow. Call it just once for the + // "sc" point, and then handle the rest with a geodetic "up" + // vector approximation. Across one tile, this will be + // acceptable. + double alt = sgCartToGeod( sc + hit_list->get_point(i) ).elev(); // cout << "hit " << i << " lon = " << geoc.lon() << " lat = " - // << lat_geod << " alt = " << alt << endl; - if ( alt > result && alt < max_alt_m ) { + // << lat_geod << " alt = " << alt << " max alt = " << max_alt_m + // << endl; + if ( alt > hit_elev && alt < max_alt_m ) { // cout << " it's a keeper" << endl; - result = alt; + hit_elev = alt; this_hit = i; } + if ( alt > hit_elev ) { + max_elev = alt; + max_hit = i; + } + } + + if ( this_hit < 0 ) { + // no hits below us, take the max hit + this_hit = max_hit; + hit_elev = max_elev; } - // cout << endl; - if ( result > -9000 ) { - *terrain_elev = result; + if ( hit_elev > -9000 ) { + *terrain_elev = hit_elev; *radius = geoc.radius(); sgVec3 tmp; sgSetVec3(tmp, hit_list->get_normal(this_hit)); @@ -559,18 +677,25 @@ bool fgCurrentElev( sgdVec3 abs_view_pos, double max_alt_m, // cout << "world_up : " << up[0] << " " << up[1] << " " << up[2] << endl; /* ssgState *IntersectedLeafState = ((ssgLeaf*)hit_list->get_entity(this_hit))->getState(); */ - return true; + result = 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; + result = false; } + + // SGTimeStamp finish; finish.stamp(); + // hitlist1_time = ( 29.0 * hitlist1_time + (finish - start) ) / 30.0; + // cout << " time per call = " << hitlist1_time << endl; + + return result; } -// ====================== +// static double hitlist2_time = 0.0; + // Determine scenery altitude via ssg. // returned results are in meters bool fgCurrentElev( sgdVec3 abs_view_pos, double max_alt_m, @@ -579,6 +704,9 @@ bool fgCurrentElev( sgdVec3 abs_view_pos, double max_alt_m, FGHitList *hit_list, double *terrain_elev, double *radius, double *normal) { + // SGTimeStamp start; start.stamp(); + + bool result; sgdVec3 view_pos; sgdSubVec3( view_pos, abs_view_pos, scenery_center ); @@ -596,25 +724,43 @@ bool fgCurrentElev( sgdVec3 abs_view_pos, double max_alt_m, sgdSetMat4(xform,fxform); hit_list->Intersect( terra_transform, xform, orig, dir ); - int this_hit=0; + int this_hit = -1; + int max_hit = -1; Point3D geoc; - double result = -9999; + double hit_elev = -9999; + double max_elev = -9999; Point3D sc(scenery_center[0], scenery_center[1], scenery_center[2]) ; int hitcount = hit_list->num_hits(); + // cout << "hits = " << hitcount << endl; 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 < max_alt_m ) { - result = alt; + // FIXME: sgCartToGeod is slow. Call it just once for the + // "sc" point, and then handle the rest with a geodetic "up" + // vector approximation. Across one tile, this will be + // acceptable. + double alt = sgCartToGeod( sc + hit_list->get_point(i) ).elev(); + // cout << "hit " << i << " lon = " << geoc.lon() << " lat = " + // << lat_geod << " alt = " << alt << " max alt = " << max_alt_m + // << endl; + if ( alt > hit_elev && alt < max_alt_m ) { + hit_elev = alt; this_hit = i; + // cout << " it's a keeper" << endl; + } + if ( alt > hit_elev ) { + max_elev = alt; + max_hit = i; } } - if ( result > -9000 ) { - *terrain_elev = result; + if ( this_hit < 0 ) { + // no hits below us, take the max hit + this_hit = max_hit; + hit_elev = max_elev; + } + + if ( hit_elev > -9000 ) { + *terrain_elev = hit_elev; *radius = geoc.radius(); sgVec3 tmp; sgSetVec3(tmp, hit_list->get_normal(this_hit)); @@ -624,11 +770,17 @@ bool fgCurrentElev( sgdVec3 abs_view_pos, double max_alt_m, // cout << "world_up : " << up[0] << " " << up[1] << " " << up[2] << endl; /* ssgState *IntersectedLeafState = ((ssgLeaf*)hit_list->get_entity(this_hit))->getState(); */ - return true; + result = true; } else { SG_LOG( SG_TERRAIN, SG_DEBUG, "DOING FULL TERRAIN INTERSECTION" ); - return fgCurrentElev( abs_view_pos, max_alt_m, scenery_center, hit_list, - terrain_elev,radius,normal); + result = fgCurrentElev( abs_view_pos, max_alt_m, scenery_center, + hit_list, terrain_elev, radius, normal); } + + // SGTimeStamp finish; finish.stamp(); + // hitlist2_time = ( 29.0 * hitlist2_time + (finish - start) ) / 30.0; + // cout << "time per call 2 = " << hitlist2_time << endl; + + return result; }