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Added ground collision detection. This involved:

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- 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)
This commit is contained in:
curt 1998-07-12 03:18:27 +00:00
parent 330c78ac73
commit 262b2f0607
7 changed files with 485 additions and 112 deletions
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153
Scenery/obj.cxx
View file

@ -60,10 +60,7 @@ using namespace std;
#include "tile.hxx"
#define MAXNODES 100000
static double nodes[MAXNODES][3];
static double normals[MAXNODES][3];
static double normals[MAX_NODES][3];
// given three points defining a triangle, calculate the normal
@ -106,7 +103,7 @@ fgPoint3d calc_tex_coords(double *node, fgPoint3d *ref) {
// Load a .obj file and build the GL fragment list
int fgObjLoad(char *path, fgTILE *tile) {
int fgObjLoad(char *path, fgTILE *t) {
fgOPTIONS *o;
fgFRAGMENT fragment;
fgPoint3d pp;
@ -116,7 +113,7 @@ int fgObjLoad(char *path, fgTILE *tile) {
// GLfloat sgenparams[] = { 1.0, 0.0, 0.0, 0.0 };
GLint display_list;
fgFile f;
int in_fragment, in_faces, ncount, vncount, n1, n2, n3, n4;
int in_fragment, in_faces, vncount, n1, n2, n3, n4;
int last1, last2, odd;
o = &current_options;
@ -140,9 +137,9 @@ int fgObjLoad(char *path, fgTILE *tile) {
}
in_fragment = 0;
ncount = 1;
t->ncount = 1;
vncount = 1;
tile->bounding_radius = 0.0;
t->bounding_radius = 0.0;
while ( fggets(f, line, 250) != NULL ) {
if ( line[0] == '#' ) {
@ -152,8 +149,8 @@ int fgObjLoad(char *path, fgTILE *tile) {
} else if ( strncmp(line, "gbs ", 4) == 0 ) {
// reference point (center offset)
sscanf(line, "gbs %lf %lf %lf %lf\n",
&tile->center.x, &tile->center.y, &tile->center.z,
&tile->bounding_radius);
&t->center.x, &t->center.y, &t->center.z,
&t->bounding_radius);
} else if ( strncmp(line, "bs ", 3) == 0 ) {
// reference point (center offset)
sscanf(line, "bs %lf %lf %lf %lf\n",
@ -161,20 +158,21 @@ int fgObjLoad(char *path, fgTILE *tile) {
&fragment.bounding_radius);
} else if ( strncmp(line, "v ", 2) == 0 ) {
// node (vertex)
if ( ncount < MAXNODES ) {
if ( t->ncount < MAX_NODES ) {
// fgPrintf( FG_TERRAIN, FG_DEBUG, "vertex = %s", line);
sscanf(line, "v %lf %lf %lf\n",
&nodes[ncount][0], &nodes[ncount][1],
&nodes[ncount][2]);
&(t->nodes[t->ncount][0]), &(t->nodes[t->ncount][1]),
&(t->nodes[t->ncount][2]));
t->ncount++;
ncount++;
} else {
fgPrintf( FG_TERRAIN, FG_EXIT,
"Read too many nodes ... dying :-(\n");
}
} else if ( strncmp(line, "vn ", 3) == 0 ) {
// vertex normal
if ( vncount < MAXNODES ) {
if ( vncount < MAX_NODES ) {
// fgPrintf( FG_TERRAIN, FG_DEBUG, "vertex normal = %s", line);
sscanf(line, "vn %lf %lf %lf\n",
&normals[vncount][0], &normals[vncount][1],
@ -197,7 +195,7 @@ int fgObjLoad(char *path, fgTILE *tile) {
fragment.display_list = display_list;
// push this fragment onto the tile's object list
tile->fragment_list.push_back(fragment);
t->fragment_list.push_back(fragment);
} else {
in_fragment = 1;
}
@ -206,11 +204,19 @@ int fgObjLoad(char *path, fgTILE *tile) {
xglNewList(display_list, GL_COMPILE);
in_faces = 0;
// reset the existing face list
// printf("cleaning a fragment with %d faces\n",
// fragment.faces.size());
while ( fragment.faces.size() ) {
// printf("emptying face list\n");
fragment.faces.pop_front();
}
// scan the material line
sscanf(line, "usemtl %s\n", material);
// give the fragment a pointer back to the tile
(fgTILE *)fragment.tile_ptr = tile;
(fgTILE *)fragment.tile_ptr = t;
// find this material in the properties list
map < string, fgMATERIAL, less<string> > :: iterator myfind =
@ -239,6 +245,8 @@ int fgObjLoad(char *path, fgTILE *tile) {
// fgPrintf( FG_TERRAIN, FG_DEBUG, " new tri strip = %s", line);
sscanf(line, "t %d %d %d %d\n", &n1, &n2, &n3, &n4);
fragment.add_face(n1, n2, n3);
// fgPrintf( FG_TERRAIN, FG_DEBUG, "(t) = ");
xglBegin(GL_TRIANGLE_STRIP);
@ -251,45 +259,45 @@ int fgObjLoad(char *path, fgTILE *tile) {
// (averaged) normals
MAT3_SCALE_VEC(normal, normals[n1], scale);
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n1], &tile->center);
pp = calc_tex_coords(t->nodes[n1], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
xglVertex3d(t->nodes[n1][0], t->nodes[n1][1], t->nodes[n1][2]);
MAT3_SCALE_VEC(normal, normals[n2], scale);
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n2], &tile->center);
pp = calc_tex_coords(t->nodes[n2], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
xglVertex3d(t->nodes[n2][0], t->nodes[n2][1], t->nodes[n2][2]);
MAT3_SCALE_VEC(normal, normals[n3], scale);
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n3], &tile->center);
pp = calc_tex_coords(t->nodes[n3], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n3][0], nodes[n3][1], nodes[n3][2]);
xglVertex3d(t->nodes[n3][0], t->nodes[n3][1], t->nodes[n3][2]);
} else {
// Shading model is "GL_FLAT" so calculate per face
// normals on the fly.
if ( odd ) {
calc_normal(nodes[n1], nodes[n2],
nodes[n3], approx_normal);
calc_normal(t->nodes[n1], t->nodes[n2],
t->nodes[n3], approx_normal);
} else {
calc_normal(nodes[n2], nodes[n1],
nodes[n3], approx_normal);
calc_normal(t->nodes[n2], t->nodes[n1],
t->nodes[n3], approx_normal);
}
MAT3_SCALE_VEC(normal, approx_normal, scale);
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n1], &tile->center);
pp = calc_tex_coords(t->nodes[n1], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
xglVertex3d(t->nodes[n1][0], t->nodes[n1][1], t->nodes[n1][2]);
pp = calc_tex_coords(nodes[n2], &tile->center);
pp = calc_tex_coords(t->nodes[n2], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
xglVertex3d(t->nodes[n2][0], t->nodes[n2][1], t->nodes[n2][2]);
pp = calc_tex_coords(nodes[n3], &tile->center);
pp = calc_tex_coords(t->nodes[n3], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n3][0], nodes[n3][1], nodes[n3][2]);
xglVertex3d(t->nodes[n3][0], t->nodes[n3][1], t->nodes[n3][2]);
}
odd = 1 - odd;
@ -297,18 +305,21 @@ int fgObjLoad(char *path, fgTILE *tile) {
last2 = n3;
if ( n4 > 0 ) {
fragment.add_face(n3, n2, n4);
if ( o->shading ) {
// Shading model is "GL_SMOOTH"
MAT3_SCALE_VEC(normal, normals[n4], scale);
} else {
// Shading model is "GL_FLAT"
calc_normal(nodes[n3], nodes[n2], nodes[n4], approx_normal);
calc_normal(t->nodes[n3], t->nodes[n2], t->nodes[n4],
approx_normal);
MAT3_SCALE_VEC(normal, approx_normal, scale);
}
xglNormal3dv(normal);
pp = calc_tex_coords(nodes[n4], &tile->center);
pp = calc_tex_coords(t->nodes[n4], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n4][0], nodes[n4][1], nodes[n4][2]);
xglVertex3d(t->nodes[n4][0], t->nodes[n4][1], t->nodes[n4][2]);
odd = 1 - odd;
last1 = n3;
@ -325,20 +336,22 @@ int fgObjLoad(char *path, fgTILE *tile) {
// fgPrintf( FG_TERRAIN, FG_DEBUG, "new triangle = %s", line);*/
sscanf(line, "f %d %d %d\n", &n1, &n2, &n3);
fragment.add_face(n1, n2, n3);
xglNormal3d(normals[n1][0], normals[n1][1], normals[n1][2]);
pp = calc_tex_coords(nodes[n1], &tile->center);
pp = calc_tex_coords(t->nodes[n1], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
xglVertex3d(t->nodes[n1][0], t->nodes[n1][1], t->nodes[n1][2]);
xglNormal3d(normals[n2][0], normals[n2][1], normals[n2][2]);
pp = calc_tex_coords(nodes[n2], &tile->center);
pp = calc_tex_coords(t->nodes[n2], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
xglVertex3d(t->nodes[n2][0], t->nodes[n2][1], t->nodes[n2][2]);
xglNormal3d(normals[n3][0], normals[n3][1], normals[n3][2]);
pp = calc_tex_coords(nodes[n3], &tile->center);
pp = calc_tex_coords(t->nodes[n3], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n3][0], nodes[n3][1], nodes[n3][2]);
xglVertex3d(t->nodes[n3][0], t->nodes[n3][1], t->nodes[n3][2]);
} else if ( line[0] == 'q' ) {
// continue a triangle strip
n1 = n2 = 0;
@ -348,6 +361,12 @@ int fgObjLoad(char *path, fgTILE *tile) {
sscanf(line, "q %d %d\n", &n1, &n2);
// fgPrintf( FG_TERRAIN, FG_DEBUG, "read %d %d\n", n1, n2);
if ( odd ) {
fragment.add_face(last1, last2, n1);
} else {
fragment.add_face(last2, last1, n1);
}
if ( o->shading ) {
// Shading model is "GL_SMOOTH"
MAT3_SCALE_VEC(normal, normals[n1], scale);
@ -355,19 +374,19 @@ int fgObjLoad(char *path, fgTILE *tile) {
} else {
// Shading model is "GL_FLAT"
if ( odd ) {
calc_normal(nodes[last1], nodes[last2], nodes[n1],
calc_normal(t->nodes[last1], t->nodes[last2], t->nodes[n1],
approx_normal);
} else {
calc_normal(nodes[last2], nodes[last1], nodes[n1],
calc_normal(t->nodes[last2], t->nodes[last1], t->nodes[n1],
approx_normal);
}
MAT3_SCALE_VEC(normal, approx_normal, scale);
xglNormal3dv(normal);
}
pp = calc_tex_coords(nodes[n1], &tile->center);
pp = calc_tex_coords(t->nodes[n1], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n1][0], nodes[n1][1], nodes[n1][2]);
xglVertex3d(t->nodes[n1][0], t->nodes[n1][1], t->nodes[n1][2]);
odd = 1 - odd;
last1 = last2;
@ -376,6 +395,12 @@ int fgObjLoad(char *path, fgTILE *tile) {
if ( n2 > 0 ) {
// fgPrintf( FG_TERRAIN, FG_DEBUG, " (cont)\n");
if ( odd ) {
fragment.add_face(last1, last2, n2);
} else {
fragment.add_face(last2, last1, n2);
}
if ( o->shading ) {
// Shading model is "GL_SMOOTH"
MAT3_SCALE_VEC(normal, normals[n2], scale);
@ -383,19 +408,19 @@ int fgObjLoad(char *path, fgTILE *tile) {
} else {
// Shading model is "GL_FLAT"
if ( odd ) {
calc_normal(nodes[last1], nodes[last2], nodes[n2],
approx_normal);
calc_normal(t->nodes[last1], t->nodes[last2],
t->nodes[n2], approx_normal);
} else {
calc_normal(nodes[last2], nodes[last1], nodes[n2],
approx_normal);
calc_normal(t->nodes[last2], t->nodes[last1],
t->nodes[n2], approx_normal);
}
MAT3_SCALE_VEC(normal, approx_normal, scale);
xglNormal3dv(normal);
}
pp = calc_tex_coords(nodes[n2], &tile->center);
pp = calc_tex_coords(t->nodes[n2], &t->center);
xglTexCoord2f(pp.lon, pp.lat);
xglVertex3d(nodes[n2][0], nodes[n2][1], nodes[n2][2]);
xglVertex3d(t->nodes[n2][0], t->nodes[n2][1], t->nodes[n2][2]);
odd = 1 -odd;
last1 = last2;
@ -416,20 +441,20 @@ int fgObjLoad(char *path, fgTILE *tile) {
fragment.display_list = display_list;
// push this fragment onto the tile's object list
tile->fragment_list.push_back(fragment);
t->fragment_list.push_back(fragment);
}
// Draw normal vectors (for visually verifying normals)
/*
xglBegin(GL_LINES);
xglColor3f(0.0, 0.0, 0.0);
for ( i = 0; i < ncount; i++ ) {
xglVertex3d(nodes[i][0],
nodes[i][1] ,
nodes[i][2]);
xglVertex3d(nodes[i][0] + 500*normals[i][0],
nodes[i][1] + 500*normals[i][1],
nodes[i][2] + 500*normals[i][2]);
for ( i = 0; i < t->ncount; i++ ) {
xglVertex3d(t->nodes[i][0],
t->nodes[i][1] ,
t->nodes[i][2]);
xglVertex3d(t->nodes[i][0] + 500*normals[i][0],
t->nodes[i][1] + 500*normals[i][1],
t->nodes[i][2] + 500*normals[i][2]);
}
xglEnd();
*/
@ -441,6 +466,14 @@ int fgObjLoad(char *path, fgTILE *tile) {
// $Log$
// Revision 1.18 1998/07/12 03:18:27 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 1.17 1998/07/08 14:47:21 curt
// Fix GL_MODULATE vs. GL_DECAL problem introduced by splash screen.
// polare3d.h renamed to polar3d.hxx

41
Scenery/scenery.cxx
View file

@ -66,31 +66,8 @@ int fgSceneryInit( void ) {
fgPrintf(FG_TERRAIN, FG_INFO, "Initializing scenery subsystem\n");
#ifdef 0
/* set the default terrain detail level */
// scenery.terrain_skip = 6;
scenery.cur_elev = -9999;
/* temp: load in a demo texture */
path[0] = '\0';
strcat(path, o->fg_root);
strcat(path, "/Textures/");
strcat(path, "desert.rgb");
// Try uncompressed
if ( (texbuf = read_rgb_texture(path, &width, &height)) == NULL ) {
// Try compressed
strcpy(fgpath, path);
strcat(fgpath, ".gz");
if ( (texbuf = read_rgb_texture(fgpath, &width, &height)) == NULL ) {
fgPrintf( FG_GENERAL, FG_EXIT, "Error in loading texture %s\n",
path );
return(0);
}
}
xglTexImage2D(GL_TEXTURE_2D, 0, 3, width, height, 0,
GL_RGB, GL_UNSIGNED_BYTE, texbuf);
#endif // 0
return(1);
}
@ -125,11 +102,19 @@ void fgSceneryRender( void ) {
/* $Log$
/* Revision 1.5 1998/06/17 21:36:41 curt
/* Load and manage multiple textures defined in the Materials library.
/* Boost max material fagments for each material property to 800.
/* Multiple texture support when rendering.
/* Revision 1.6 1998/07/12 03:18:27 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 1.5 1998/06/17 21:36:41 curt
* Load and manage multiple textures defined in the Materials library.
* Boost max material fagments for each material property to 800.
* Multiple texture support when rendering.
*
* Revision 1.4 1998/05/13 18:26:40 curt
* Root path info moved to fgOPTIONS.
*

25
Scenery/scenery.hxx
View file

@ -38,9 +38,6 @@
/* Define a structure containing global scenery parameters */
struct fgSCENERY {
/* number of terrain data points to skip */
int terrain_skip;
/* center of current scenery chunk */
fgPoint3d center;
@ -49,6 +46,10 @@ struct fgSCENERY {
/* angle of sun relative to current local horizontal */
double sun_angle;
// elevation of terrain at our current lat/lon (based on the
// actual drawn polygons)
double cur_elev;
};
extern struct fgSCENERY scenery;
@ -71,12 +72,20 @@ void fgSceneryRender( void );
/* $Log$
/* Revision 1.3 1998/07/08 14:47:22 curt
/* Fix GL_MODULATE vs. GL_DECAL problem introduced by splash screen.
/* polare3d.h renamed to polar3d.hxx
/* fg{Cartesian,Polar}Point3d consolodated.
/* Added some initial support for calculating local current ground elevation.
/* Revision 1.4 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 1.3 1998/07/08 14:47:22 curt
* Fix GL_MODULATE vs. GL_DECAL problem introduced by splash screen.
* polare3d.h renamed to polar3d.hxx
* fg{Cartesian,Polar}Point3d consolodated.
* Added some initial support for calculating local current ground elevation.
*
* Revision 1.2 1998/05/02 01:52:16 curt
* Playing around with texture coordinates.
*

271
Scenery/tile.cxx
View file

@ -22,6 +22,10 @@
// (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"
@ -30,22 +34,289 @@ fgFRAGMENT::fgFRAGMENT ( void ) {
}
// 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);
}
// 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);
}
// 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
// does, 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 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 = (fgTILE *)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;
a1 = x1 - x0;
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 ) {
result->x = (t1*x0 - b*y0 + t2*x0 - c*z0 + d) / (a + t1 + t2);
result->y = (b1/a1) * (result->x - x0) + y0;
result->z = (c1/a1) * (result->x - x0) + z0;
// printf("result(d) = %.2f\n",
// a * result->x + b * result->y + c * result->z);
} else {
// no intersection point
continue;
}
if ( side_flag ) {
// check to see if end0 and end1 are on opposite sides of
// plane
if ( (result->x - x0) > FG_EPSILON ) {
t1 = result->x; t2 = x0; t3 = x1;
} else if ( (result->y - y0) > FG_EPSILON ) {
t1 = result->y; t2 = y0; t3 = y1;
} else if ( (result->z - z0) > FG_EPSILON ) {
t1 = result->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
return(1);
}
if ( fg_sign(t1 - t2) == fg_sign(t1 - t3) ) {
// same side, punt
continue;
}
}
// check to see if intersection point is in the bounding
// cube of the face
xmin = fg_min(p1[0], p2[0], p3[0]);
xmax = fg_max(p1[0], p2[0], p3[0]);
ymin = fg_min(p1[1], p2[1], p3[1]);
ymax = fg_max(p1[1], p2[1], p3[1]);
zmin = fg_min(p1[2], p2[2], p3[2]);
zmax = fg_max(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 ( result->x < xmin ) {
continue;
} else if ( result->x > xmax ) {
continue;
} else if ( result->y < ymin ) {
continue;
} else if ( result->y > ymax ) {
continue;
} else if ( result->z < zmin ) {
continue;
} else if ( result->z > zmax ) {
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_min(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 = result->y; ry = result->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 = result->x; ry = result->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 = result->x; ry = result->y;
}
// check if intersection point is on the same side of p1 <-> p2 as p3
side1 = fg_sign((y1 - y2) * ((x3) - x2) / (x1 - x2) + y2 - (y3));
side2 = fg_sign((y1 - y2) * ((rx) - x2) / (x1 - 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
side1 = fg_sign((y2 - y3) * ((x1) - x3) / (x2 - x3) + y3 - (y1));
side2 = fg_sign((y2 - y3) * ((rx) - x3) / (x2 - 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
side1 = fg_sign((y1 - y3) * ((x2) - x3) / (x1 - x3) + y3 - (y2));
side2 = fg_sign((y1 - y3) * ((rx) - x3) / (x1 - x3) + y3 - (ry));
if ( side1 != side2 ) {
// printf("failed side 3 check\n");
continue;
}
// printf( "intersection point = %.2f %.2f %.2f\n",
// result->x, result->y, result->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();
}
}
// Constructor
fgTILE::fgTILE ( void ) {
nodes = new double[MAX_NODES][3];
}
// Destructor
fgTILE::~fgTILE ( void ) {
free(nodes);
}
// $Log$
// 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

36
Scenery/tile.hxx
View file

@ -53,6 +53,16 @@ using namespace std;
#include <Bucket/bucketutils.h>
#include <Include/fg_types.h>
#include <Math/mat3.h>
// Maximum nodes per tile
#define MAX_NODES 1000
typedef struct {
int n1, n2, n3;
} fgFACE;
// Object fragment data class
@ -82,9 +92,23 @@ public:
// OpenGL display list for fragment data
GLint display_list;
// face list (this indexes into the master tile vertex list)
list < fgFACE > faces;
// Constructor
fgFRAGMENT ( void );
// Add a face to the face list
void add_face(int n1, int n2, int n3);
// 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 does, 0 otherwise. If it intesects, result is the
// point of intersection
int intersect( fgPoint3d *end0, fgPoint3d *end1, int side_flag,
fgPoint3d *result);
// Destructor
~fgFRAGMENT ( void );
};
@ -95,6 +119,10 @@ class fgTILE {
public:
// node list (the per fragment face lists reference this node list)
double (*nodes)[3];
int ncount;
// culling data for whole tile (course grain culling)
fgPoint3d center;
double bounding_radius;
@ -121,6 +149,14 @@ public:
// $Log$
// Revision 1.11 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 1.10 1998/07/08 14:47:22 curt
// Fix GL_MODULATE vs. GL_DECAL problem introduced by splash screen.
// polare3d.h renamed to polar3d.hxx

18
Scenery/tilecache.cxx
View file

@ -39,6 +39,7 @@
#include <Main/views.hxx>
#include "obj.hxx"
#include "tile.hxx"
#include "tilecache.hxx"
@ -117,7 +118,7 @@ void fgTILECACHE::EntryFillIn( int index, fgBUCKET *p ) {
// Free a tile cache entry
void fgTILECACHE::EntryFree( int index ) {
fgFRAGMENT fragment;
fgFRAGMENT *fragment;
// Mark this cache entry as un-used
tile_cache[index].used = 0;
@ -133,8 +134,11 @@ void fgTILECACHE::EntryFree( int index ) {
// Step through the fragment list, deleting the display list, then
// the fragment, until the list is empty.
while ( tile_cache[index].fragment_list.size() ) {
fragment = tile_cache[index].fragment_list.front();
xglDeleteLists( fragment.display_list, 1 );
list < fgFRAGMENT > :: iterator current =
tile_cache[index].fragment_list.begin();
fragment = &(*current);
xglDeleteLists( fragment->display_list, 1 );
tile_cache[index].fragment_list.pop_front();
}
}
@ -209,6 +213,14 @@ fgTILECACHE::~fgTILECACHE( void ) {
// $Log$
// Revision 1.12 1998/07/12 03:18:29 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 1.11 1998/07/04 00:54:30 curt
// Added automatic mipmap generation.
//

53
Scenery/tilemgr.cxx
View file

@ -316,13 +316,13 @@ void fgTileMgrRender( void ) {
fgTILECACHE *c;
fgFLIGHT *f;
fgOPTIONS *o;
fgTILE *t;
fgTILE *t, *last_tile_ptr;
fgVIEW *v;
fgBUCKET p;
fgPoint3d frag_offset, fc, pp;
fgPoint3d frag_offset, pp;
fgPoint3d earth_center, result;
fgFRAGMENT *frag_ptr;
fgMATERIAL *mtl_ptr;
fgTILE *last_tile_ptr;
GLdouble *m;
double dist, min_dist, lat_geod, alt, sea_level_r;
double x, y, z;
@ -343,6 +343,14 @@ void fgTileMgrRender( void ) {
index = c->Exists(&p);
t = c->GetTile(index);
scenery.next_center.x = t->center.x;
scenery.next_center.y = t->center.y;
scenery.next_center.z = t->center.z;
earth_center.x = 0.0;
earth_center.y = 0.0;
earth_center.z = 0.0;
fgPrintf( FG_TERRAIN, FG_DEBUG,
"Pos = (%.2f, %.2f) Current bucket = %d %d %d %d Index = %ld\n",
FG_Longitude * RAD_TO_DEG, FG_Latitude * RAD_TO_DEG,
@ -370,6 +378,7 @@ void fgTileMgrRender( void ) {
}
// Calculate the model_view transformation matrix for this tile
// This is equivalent to doing a glTranslatef(x, y, z);
m[12] = m[0] * x + m[4] * y + m[8] * z + m[12];
m[13] = m[1] * x + m[5] * y + m[9] * z + m[13];
m[14] = m[2] * x + m[6] * y + m[10] * z + m[14];
@ -378,7 +387,12 @@ void fgTileMgrRender( void ) {
// temp ... calc current terrain elevation
// calculate distance from vertical tangent line at
// current position to center of tile.
dist = point_line_dist(&(t->offset), &(v->view_pos), v->local_up);
/* printf("distance = %.2f, bounding radius = %.2f\n",
point_line_dist(&(t->offset), &(v->view_pos), v->local_up),
t->bounding_radius); */
dist = point_line_dist(&(t->center), &(v->abs_view_pos), v->local_up);
if ( dist < t->bounding_radius ) {
// traverse fragment list for tile
@ -388,23 +402,28 @@ void fgTileMgrRender( void ) {
while ( current != last ) {
frag_ptr = &(*current);
current++;
dist = point_line_dist( &(frag_ptr->center), &(v->view_pos),
v->local_up);
/* printf("distance = %.2f, bounding radius = %.2f\n",
point_line_dist( &(frag_ptr->center),
&(v->abs_view_pos), v->local_up),
frag_ptr->bounding_radius); */
dist = point_line_dist( &(frag_ptr->center),
&(v->abs_view_pos), v->local_up);
if ( dist <= frag_ptr->bounding_radius ) {
if ( dist < min_dist ) {
min_dist = dist;
if ( frag_ptr->intersect( &(v->abs_view_pos),
&earth_center, 0, &result ) ) {
// compute geocentric coordinates of tile center
pp = fgCartToPolar3d(frag_ptr->center);
pp = fgCartToPolar3d(result);
// convert to geodetic coordinates
fgGeocToGeod(pp.lat, pp.radius, &lat_geod,
&alt, &sea_level_r);
// printf("alt = %.2f\n", alt);
scenery.cur_elev = alt;
// exit this loop since we found an intersection
break;
}
}
}
if ( min_dist <= t->bounding_radius ) {
printf("min_dist = %.2f alt = %.2f\n", min_dist, alt);
}
}
// Course (tile based) culling
@ -531,6 +550,14 @@ void fgTileMgrRender( void ) {
// $Log$
// Revision 1.24 1998/07/12 03:18:29 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 1.23 1998/07/08 14:47:23 curt
// Fix GL_MODULATE vs. GL_DECAL problem introduced by splash screen.
// polare3d.h renamed to polar3d.hxx