void CCourse::CalcNormals () {
for (int y=0; y<ny; y++) {
for (int x=0; x<nx; x++) {
TVector3 nml(0.0, 0.0, 0.0);
TVector3 p0 (XCD(x), ELEV(x,y), ZCD(y));
if ((x + y) % 2 == 0) {
if (x > 0 && y > 0) {
TVector3 p1 = NMLPOINT(x, y-1);
TVector3 p2 = NMLPOINT(x-1,y-1);
TVector3 v1 = SubtractVectors (p1, p0);
TVector3 v2 = SubtractVectors (p2, p0);
TVector3 n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
p1 = NMLPOINT (x-1, y-1);
p2 = NMLPOINT (x-1, y);
v1 = SubtractVectors (p1, p0);
v2 = SubtractVectors (p2, p0);
n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
}
if (x > 0 && y < ny-1) {
TVector3 p1 = NMLPOINT(x-1,y);
TVector3 p2 = NMLPOINT(x-1,y+1);
TVector3 v1 = SubtractVectors (p1, p0);
TVector3 v2 = SubtractVectors (p2, p0);
TVector3 n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
p1 = NMLPOINT(x-1,y+1);
p2 = NMLPOINT(x ,y+1);
v1 = SubtractVectors (p1, p0);
v2 = SubtractVectors (p2, p0);
n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
}
if (x < nx-1 && y > 0) {
TVector3 p1 = NMLPOINT(x+1,y);
TVector3 p2 = NMLPOINT(x+1,y-1);
TVector3 v1 = SubtractVectors (p1, p0);
TVector3 v2 = SubtractVectors (p2, p0);
TVector3 n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
p1 = NMLPOINT(x+1,y-1);
p2 = NMLPOINT(x ,y-1);
v1 = SubtractVectors (p1, p0);
v2 = SubtractVectors (p2, p0);
n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
}
if (x < nx-1 && y < ny-1) {
TVector3 p1 = NMLPOINT(x+1,y);
TVector3 p2 = NMLPOINT(x+1,y+1);
TVector3 v1 = SubtractVectors (p1, p0);
TVector3 v2 = SubtractVectors (p2, p0);
TVector3 n = CrossProduct (v1, v2);
NormVector (n);
nml = AddVectors (nml, n);
p1 = NMLPOINT(x+1,y+1);
p2 = NMLPOINT(x ,y+1);
v1 = SubtractVectors (p1, p0);
v2 = SubtractVectors (p2, p0);
n = CrossProduct (v1, v2);
NormVector (n);
nml = AddVectors (nml, n);
}
} else {
if (x > 0 && y > 0) {
TVector3 p1 = NMLPOINT(x, y-1);
TVector3 p2 = NMLPOINT(x-1,y);
TVector3 v1 = SubtractVectors (p1, p0);
TVector3 v2 = SubtractVectors (p2, p0);
TVector3 n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
}
if (x > 0 && y < ny-1) {
TVector3 p1 = NMLPOINT(x-1,y);
TVector3 p2 = NMLPOINT(x ,y+1);
TVector3 v1 = SubtractVectors (p1, p0);
TVector3 v2 = SubtractVectors (p2, p0);
TVector3 n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
}
if (x < nx-1 && y > 0) {
TVector3 p1 = NMLPOINT(x+1,y);
TVector3 p2 = NMLPOINT(x ,y-1);
TVector3 v1 = SubtractVectors (p1, p0);
TVector3 v2 = SubtractVectors (p2, p0);
TVector3 n = CrossProduct (v2, v1);
NormVector (n);
nml = AddVectors (nml, n);
}
if (x < nx-1 && y < ny-1) {
TVector3 p1 = NMLPOINT(x+1,y);
TVector3 p2 = NMLPOINT(x ,y+1);
TVector3 v1 = SubtractVectors (p1, p0);
TVector3 v2 = SubtractVectors (p2, p0);
TVector3 n = CrossProduct (v1, v2);
NormVector (n);
nml = AddVectors (nml, n);
}
}
NormVector (nml);
nmls [x + nx * y] = nml;
continue;
}
}
}
void calc_normals(const char *course)
{
scalar_t *elevation;
scalar_t courseWidth, courseLength;
int nx, ny;
int x,y;
point_t p0, p1, p2;
vector_t n, nml, v1, v2;
char buff[BUFF_LEN];
sprintf( buff, "%s/courses/%s/normal.data", getparam_data_dir(), course );
get_course_dimensions( &courseWidth, &courseLength );
get_course_divisions( &nx, &ny );
if(nmls != (void*)-1 && nmls_fd != -1)
{
munmap(nmls, nmls_len);
close(nmls_fd);
}
#if 0
else {
free(nmls);
}
#endif
struct stat buf;
int exists = (stat(buff, &buf) == 0);
if(exists) {
nmls_fd = open(buff, O_RDONLY);
if ( nmls_fd == -1) {
handle_system_error( 1, "can't open file failed" );
}
TRDebugLog("mapping to memory normal.data\n");
nmls_len = sizeof(vector_t)*nx*ny;
nmls = mmap(NULL, nmls_len, PROT_READ, MAP_SHARED,nmls_fd, 0);
if ( nmls == (void *)-1 ) {
handle_system_error( 1, "read mmap failed" );
}
}
else {
nmls_len = sizeof(vector_t)*nx*ny;
#if TARGET_IPHONE_SIMULATOR
nmls_fd = open(buff, O_RDWR | O_CREAT | O_TRUNC, 0644);
if ( nmls_fd == -1) {
handle_system_error( 1, "can't open file failed" );
}
int result = lseek(nmls_fd, nmls_len-1, SEEK_SET);
if (result == -1) {
handle_system_error( 1, "can't write file failed" );
}
result = write(nmls_fd, "", 1);
if (result != 1) {
handle_system_error( 1, "can't write file failed" );
}
nmls = mmap(NULL, nmls_len, PROT_READ | PROT_WRITE, MAP_SHARED, nmls_fd, 0);
if ( nmls == (void *)-1 ) {
handle_system_error( 1, "write mmap failed" );
}
TRDebugLog("Writing to normal.data\n");
#else
# ifdef TR_DEBUG_MODE
abort(); // This shouldn't be reached on simulator. Crash to indicate.
# endif
nmls = malloc(nmls_len);
#endif
elevation = get_course_elev_data();
for ( y=0; y<ny; y++) {
for ( x=0; x<nx; x++) {
nml = make_vector( 0., 0., 0. );
p0 = make_point( XCD(x), ELEV(x,y), ZCD(y) );
/* The terrain is meshed as follows:
...
+-+-+-+-+ x<---+
|\|/|\|/| |
...+-+-+-+-+... V
|/|\|/|\| y
+-+-+-+-+
...
So there are two types of vertices: those surrounded by
four triangles (x+y is odd), and those surrounded by
eight (x+y is even).
*/
#define POINT(x,y) make_point( XCD(x), ELEV(x,y), ZCD(y) )
if ( (x + y) % 2 == 0 ) {
if ( x > 0 && y > 0 ) {
p1 = POINT(x, y-1);
p2 = POINT(x-1,y-1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
p1 = POINT(x-1,y-1);
p2 = POINT(x-1,y );
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
}
if ( x > 0 && y < ny-1 ) {
p1 = POINT(x-1,y );
p2 = POINT(x-1,y+1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
p1 = POINT(x-1,y+1);
p2 = POINT(x ,y+1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
}
if ( x < nx-1 && y > 0 ) {
p1 = POINT(x+1,y );
p2 = POINT(x+1,y-1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
p1 = POINT(x+1,y-1);
p2 = POINT(x ,y-1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
}
if ( x < nx-1 && y < ny-1 ) {
p1 = POINT(x+1,y );
p2 = POINT(x+1,y+1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v1, v2 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
p1 = POINT(x+1,y+1);
p2 = POINT(x ,y+1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v1, v2 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
}
} else {
/* x + y is odd */
if ( x > 0 && y > 0 ) {
p1 = POINT(x, y-1);
p2 = POINT(x-1,y );
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
}
if ( x > 0 && y < ny-1 ) {
p1 = POINT(x-1,y );
p2 = POINT(x ,y+1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
}
if ( x < nx-1 && y > 0 ) {
p1 = POINT(x+1,y );
p2 = POINT(x ,y-1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v2, v1 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
}
if ( x < nx-1 && y < ny-1 ) {
p1 = POINT(x+1,y );
p2 = POINT(x ,y+1);
v1 = subtract_points( p1, p0 );
v2 = subtract_points( p2, p0 );
n = cross_product( v1, v2 );
check_assertion( n.y > 0, "course normal points down" );
normalize_vector( &n );
nml = add_vectors( nml, n );
}
}
normalize_vector( &nml );
NORMAL(x,y) = nml;
continue;
}
#undef POINT
}
#if TARGET_IPHONE_SIMULATOR
munmap(nmls, nmls_len);
close(nmls_fd);
nmls_fd = open(buff, O_RDONLY);
if (nmls_fd == -1) {
handle_system_error( 1, "can't remount normal.data" );
}
TRDebugLog("remounting to memory normal.data\n");
nmls_len = sizeof(vector_t)*nx*ny;
nmls = mmap(NULL, nmls_len, PROT_READ, MAP_SHARED, nmls_fd, 0);
if ( nmls == (void *)-1 ) {
handle_system_error( 1, "remount mmap failed" );
}
#endif
}
}