// (Log is kept at end of this file)
+#include <Include/fg_constants.h>
+#include <Include/fg_types.h>
+#include <Math/mat3.h>
+
#include "tile.hxx"
+// return the sign of a value
+#define FG_SIGN( x ) ((x) < 0 ? -1 : 1)
+
+// return min or max of two values
+#define FG_MIN(A,B) ((A) < (B) ? (A) : (B))
+#define FG_MAX(A,B) ((A) > (B) ? (A) : (B))
+
+
+fgFACE :: fgFACE () :
+ n1(0), n2(0), n3(0)
+{
+}
+
+fgFACE :: ~fgFACE()
+{
+}
+
+fgFACE :: fgFACE( const fgFACE & image ) :
+ n1( image.n1), n2( image.n2), n3( image.n3)
+{
+}
+
+bool fgFACE :: operator < (const fgFACE & rhs )
+{
+ return ( n1 < rhs.n1 ? true : false);
+}
+
+bool fgFACE :: operator == (const fgFACE & rhs )
+{
+ return ((n1 == rhs.n1) && (n2 == rhs.n2) && ( n3 == rhs.n3));
+}
+
+
// Constructor
fgFRAGMENT::fgFRAGMENT ( void ) {
}
+// Copy constructor
+fgFRAGMENT :: fgFRAGMENT ( const fgFRAGMENT & rhs ) :
+ center ( rhs.center ),
+ bounding_radius( rhs.bounding_radius ),
+ material_ptr ( rhs.material_ptr ),
+ tile_ptr ( rhs.tile_ptr ),
+ display_list ( rhs.display_list ),
+ faces ( rhs.faces ),
+ num_faces ( rhs.num_faces )
+{
+}
+
+fgFRAGMENT & fgFRAGMENT :: operator = ( const fgFRAGMENT & rhs )
+{
+ if(!(this == &rhs )) {
+ center = rhs.center;
+ bounding_radius = rhs.bounding_radius;
+ material_ptr = rhs.material_ptr;
+ tile_ptr = rhs.tile_ptr;
+ // display_list = rhs.display_list;
+ faces = rhs.faces;
+ }
+ return *this;
+}
+
+
+// Add a face to the face list
+void fgFRAGMENT::add_face(int n1, int n2, int n3) {
+ fgFACE face;
+
+ face.n1 = n1;
+ face.n2 = n2;
+ face.n3 = n3;
+
+ faces.push_back(face);
+ num_faces++;
+}
+
+
+/*
+// return the sign of a value
+static int fg_sign( double x ) {
+ if ( x >= 0 ) {
+ return(1);
+ } else {
+ return(-1);
+ }
+}
+
+
+// return the minimum of the three values
+static double fg_min( double a, double b, double c ) {
+ double result;
+ result = a;
+ if (result > b) result = b;
+ if (result > c) result = c;
+
+ return(result);
+}
+
+
+// return the maximum of the three values
+static double fg_max( double a, double b, double c ) {
+ double result;
+ result = a;
+ if (result < b) result = b;
+ if (result < c) result = c;
+
+ return(result);
+}
+*/
+
+
+// return the minimum of the three values
+static double fg_min3 (double a, double b, double c)
+{
+ return (a > b ? FG_MIN (b, c) : FG_MIN (a, c));
+}
+
+
+// return the maximum of the three values
+static double fg_max3 (double a, double b, double c)
+{
+ return (a < b ? FG_MAX (b, c) : FG_MAX (a, c));
+}
+
+
+// test if line intesects with this fragment. p0 and p1 are the two
+// line end points of the line. If side_flag is true, check to see
+// that end points are on opposite sides of face. Returns 1 if it
+// intersection found, 0 otherwise. If it intesects, result is the
+// point of intersection
+
+int fgFRAGMENT::intersect( fgPoint3d *end0, fgPoint3d *end1, int side_flag,
+ fgPoint3d *result)
+{
+ fgTILE *t;
+ fgFACE face;
+ MAT3vec v1, v2, n, center;
+ double p1[3], p2[3], p3[3];
+ double x, y, z; // temporary holding spot for result
+ double a, b, c, d;
+ double x0, y0, z0, x1, y1, z1, a1, b1, c1;
+ double t1, t2, t3;
+ double xmin, xmax, ymin, ymax, zmin, zmax;
+ double dx, dy, dz, min_dim, x2, y2, x3, y3, rx, ry;
+ int side1, side2;
+ list < fgFACE > :: iterator current;
+ list < fgFACE > :: iterator last;
+
+ // find the associated tile
+ t = tile_ptr;
+
+ // printf("Intersecting\n");
+
+ // traverse the face list for this fragment
+ current = faces.begin();
+ last = faces.end();
+ while ( current != last ) {
+ face = *current;
+ current++;
+
+ // printf(".");
+
+ // get face vertex coordinates
+ center[0] = t->center.x;
+ center[1] = t->center.y;
+ center[2] = t->center.z;
+
+ MAT3_ADD_VEC(p1, t->nodes[face.n1], center);
+ MAT3_ADD_VEC(p2, t->nodes[face.n2], center);
+ MAT3_ADD_VEC(p3, t->nodes[face.n3], center);
+
+ // printf("point 1 = %.2f %.2f %.2f\n", p1[0], p1[1], p1[2]);
+ // printf("point 2 = %.2f %.2f %.2f\n", p2[0], p2[1], p2[2]);
+ // printf("point 3 = %.2f %.2f %.2f\n", p3[0], p3[1], p3[2]);
+
+ // calculate two edge vectors, and the face normal
+ MAT3_SUB_VEC(v1, p2, p1);
+ MAT3_SUB_VEC(v2, p3, p1);
+ MAT3cross_product(n, v1, v2);
+
+ // calculate the plane coefficients for the plane defined by
+ // this face. If n is the normal vector, n = (a, b, c) and p1
+ // is a point on the plane, p1 = (x0, y0, z0), then the
+ // equation of the line is a(x-x0) + b(y-y0) + c(z-z0) = 0
+ a = n[0];
+ b = n[1];
+ c = n[2];
+ d = a * p1[0] + b * p1[1] + c * p1[2];
+ // printf("a, b, c, d = %.2f %.2f %.2f %.2f\n", a, b, c, d);
+
+ // printf("p1(d) = %.2f\n", a * p1[0] + b * p1[1] + c * p1[2]);
+ // printf("p2(d) = %.2f\n", a * p2[0] + b * p2[1] + c * p2[2]);
+ // printf("p3(d) = %.2f\n", a * p3[0] + b * p3[1] + c * p3[2]);
+
+ // calculate the line coefficients for the specified line
+ x0 = end0->x; x1 = end1->x;
+ y0 = end0->y; y1 = end1->y;
+ z0 = end0->z; z1 = end1->z;
+
+ if ( fabs(x1 - x0) > FG_EPSILON ) {
+ a1 = 1.0 / (x1 - x0);
+ } else {
+ // we got a big divide by zero problem here
+ a1 = 0.0;
+ }
+ b1 = y1 - y0;
+ c1 = z1 - z0;
+
+ // intersect the specified line with this plane
+ t1 = b * b1 * a1;
+ t2 = c * c1 * a1;
+
+ // printf("a = %.2f t1 = %.2f t2 = %.2f\n", a, t1, t2);
+
+ if ( fabs(a + t1 + t2) > FG_EPSILON ) {
+ x = (t1*x0 - b*y0 + t2*x0 - c*z0 + d) / (a + t1 + t2);
+ t3 = a1 * (x - x0);
+ y = b1 * t3 + y0;
+ z = c1 * t3 + z0;
+ // printf("result(d) = %.2f\n", a * x + b * y + c * z);
+ } else {
+ // no intersection point
+ continue;
+ }
+
+ if ( side_flag ) {
+ // check to see if end0 and end1 are on opposite sides of
+ // plane
+ if ( (x - x0) > FG_EPSILON ) {
+ t1 = x;
+ t2 = x0;
+ t3 = x1;
+ } else if ( (y - y0) > FG_EPSILON ) {
+ t1 = y;
+ t2 = y0;
+ t3 = y1;
+ } else if ( (z - z0) > FG_EPSILON ) {
+ t1 = z;
+ t2 = z0;
+ t3 = z1;
+ } else {
+ // everything is too close together to tell the difference
+ // so the current intersection point should work as good
+ // as any
+ result->x = x;
+ result->y = y;
+ result->z = z;
+ return(1);
+ }
+ side1 = FG_SIGN (t1 - t2);
+ side2 = FG_SIGN (t1 - t3);
+ if ( side1 == side2 ) {
+ // same side, punt
+ continue;
+ }
+ }
+
+ // check to see if intersection point is in the bounding
+ // cube of the face
+ xmin = fg_min3 (p1[0], p2[0], p3[0]);
+ xmax = fg_max3 (p1[0], p2[0], p3[0]);
+ ymin = fg_min3 (p1[1], p2[1], p3[1]);
+ ymax = fg_max3 (p1[1], p2[1], p3[1]);
+ zmin = fg_min3 (p1[2], p2[2], p3[2]);
+ zmax = fg_max3 (p1[2], p2[2], p3[2]);
+ // printf("bounding cube = %.2f,%.2f,%.2f %.2f,%.2f,%.2f\n",
+ // xmin, ymin, zmin, xmax, ymax, zmax);
+ // punt if outside bouding cube
+ if ( x < (xmin = fg_min3 (p1[0], p2[0], p3[0])) ) {
+ continue;
+ } else if ( x > (xmax = fg_max3 (p1[0], p2[0], p3[0])) ) {
+ continue;
+ } else if ( y < (ymin = fg_min3 (p1[1], p2[1], p3[1])) ) {
+ continue;
+ } else if ( y > (ymax = fg_max3 (p1[1], p2[1], p3[1])) ) {
+ continue;
+ } else if ( z < (zmin = fg_min3 (p1[2], p2[2], p3[2])) ) {
+ continue;
+ } else if ( z > (zmax = fg_max3 (p1[2], p2[2], p3[2])) ) {
+ continue;
+ }
+
+ // (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.
+ dx = xmax - xmin;
+ dy = ymax - ymin;
+ dz = zmax - zmin;
+ min_dim = fg_min3 (dx, dy, dz);
+ if ( fabs(min_dim - dx) <= FG_EPSILON ) {
+ // x is the smallest dimension
+ x1 = p1[1];
+ y1 = p1[2];
+ x2 = p2[1];
+ y2 = p2[2];
+ x3 = p3[1];
+ y3 = p3[2];
+ rx = y;
+ ry = z;
+ } else if ( fabs(min_dim - dy) <= FG_EPSILON ) {
+ // y is the smallest dimension
+ x1 = p1[0];
+ y1 = p1[2];
+ x2 = p2[0];
+ y2 = p2[2];
+ x3 = p3[0];
+ y3 = p3[2];
+ rx = x;
+ ry = z;
+ } else if ( fabs(min_dim - dz) <= FG_EPSILON ) {
+ // z is the smallest dimension
+ x1 = p1[0];
+ y1 = p1[1];
+ x2 = p2[0];
+ y2 = p2[1];
+ x3 = p3[0];
+ y3 = p3[1];
+ rx = x;
+ ry = y;
+ } else {
+ // all dimensions are really small so lets call it close
+ // enough and return a successful match
+ result->x = x;
+ result->y = y;
+ result->z = z;
+ return(1);
+ }
+
+ // check if intersection point is on the same side of p1 <-> p2 as p3
+ t1 = (y1 - y2) / (x1 - x2);
+ side1 = FG_SIGN (t1 * ((x3) - x2) + y2 - (y3));
+ side2 = FG_SIGN (t1 * ((rx) - x2) + y2 - (ry));
+ if ( side1 != side2 ) {
+ // printf("failed side 1 check\n");
+ continue;
+ }
+
+ // check if intersection point is on correct side of p2 <-> p3 as p1
+ t1 = (y2 - y3) / (x2 - x3);
+ side1 = FG_SIGN (t1 * ((x1) - x3) + y3 - (y1));
+ side2 = FG_SIGN (t1 * ((rx) - x3) + y3 - (ry));
+ if ( side1 != side2 ) {
+ // printf("failed side 2 check\n");
+ continue;
+ }
+
+ // check if intersection point is on correct side of p1 <-> p3 as p2
+ t1 = (y1 - y3) / (x1 - x3);
+ side1 = FG_SIGN (t1 * ((x2) - x3) + y3 - (y2));
+ side2 = FG_SIGN (t1 * ((rx) - x3) + y3 - (ry));
+ if ( side1 != side2 ) {
+ // printf("failed side 3 check\n");
+ continue;
+ }
+
+ // printf( "intersection point = %.2f %.2f %.2f\n", x, y, z);
+ result->x = x;
+ result->y = y;
+ result->z = z;
+ return(1);
+ }
+
+ // printf("\n");
+
+ return(0);
+}
+
+
// Destructor
fgFRAGMENT::~fgFRAGMENT ( void ) {
+ // Step through the face list deleting the items until the list is
+ // empty
+
+ // printf("destructing a fragment with %d faces\n", faces.size());
+
+ while ( faces.size() ) {
+ // printf("emptying face list\n");
+ faces.pop_front();
+ }
+}
+
+
+// equality operator
+bool fgFRAGMENT :: operator == ( const fgFRAGMENT & rhs)
+{
+ if(( center.x - rhs.center.x ) < FG_EPSILON) {
+ if(( center.y - rhs.center.y) < FG_EPSILON) {
+ if(( center.z - rhs.center.z) < FG_EPSILON) {
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+// comparison operator
+bool fgFRAGMENT :: operator < ( const fgFRAGMENT &rhs)
+{
+ // This is completely arbitrary. It satisfies RW's STL implementation
+
+ return bounding_radius < rhs.bounding_radius;
}
// Constructor
fgTILE::fgTILE ( void ) {
+ nodes = new double[MAX_NODES][3];
}
// Destructor
fgTILE::~fgTILE ( void ) {
+ free(nodes);
}
// $Log$
+// Revision 1.8 1998/08/22 14:49:58 curt
+// Attempting to iron out seg faults and crashes.
+// Did some shuffling to fix a initialization order problem between view
+// position, scenery elevation.
+//
+// Revision 1.7 1998/08/20 15:12:05 curt
+// Used a forward declaration of classes fgTILE and fgMATERIAL to eliminate
+// the need for "void" pointers and casts.
+// Quick hack to count the number of scenery polygons that are being drawn.
+//
+// Revision 1.6 1998/08/12 21:13:05 curt
+// material.cxx: don't load textures if they are disabled
+// obj.cxx: optimizations from Norman Vine
+// tile.cxx: minor tweaks
+// tile.hxx: addition of num_faces
+// tilemgr.cxx: minor tweaks
+//
+// Revision 1.5 1998/07/24 21:42:08 curt
+// material.cxx: whups, double method declaration with no definition.
+// obj.cxx: tweaks to avoid errors in SGI's CC.
+// tile.cxx: optimizations by Norman Vine.
+// tilemgr.cxx: optimizations by Norman Vine.
+//
+// Revision 1.4 1998/07/22 21:41:42 curt
+// Add basic fgFACE methods contributed by Charlie Hotchkiss.
+// intersect optimization from Norman Vine.
+//
+// Revision 1.3 1998/07/16 17:34:24 curt
+// Ground collision detection optimizations contributed by Norman Vine.
+//
+// Revision 1.2 1998/07/12 03:18:28 curt
+// Added ground collision detection. This involved:
+// - saving the entire vertex list for each tile with the tile records.
+// - saving the face list for each fragment with the fragment records.
+// - code to intersect the current vertical line with the proper face in
+// an efficient manner as possible.
+// Fixed a bug where the tiles weren't being shifted to "near" (0,0,0)
+//
// Revision 1.1 1998/05/23 14:09:21 curt
// Added tile.cxx and tile.hxx.
// Working on rewriting the tile management system so a tile is just a list
projects / flightgear.git / blobdiff