Minor transformation adjustments to try to keep scenery tiles closer to

(0, 0, 0)  GLfloats run out of precision at the distances we need to model
the earth, but we can do a bunch of pre-transformations using double math
and then cast to GLfloat once everything is close in where we have less
precision problems.

diff --git a/Scenery/obj.c b/Scenery/obj.c
index fd6f807da4ecdb155108c1ba7a34603370727d0f..41d17ad5487ea32925bf2c68fd96e513f0976a05 100644 (file)
--- a/Scenery/obj.c
+++ b/Scenery/obj.c
@@ -95,7 +95,7 @@ float calc_lat(double x, double y, double z) {
 GLint fgObjLoad(char *path, struct fgCartesianPoint *ref, double *radius) {
     char gzpath[256], line[256], winding_str[256];
     double approx_normal[3], normal[3], scale;
-    double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
+    // double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
     GLfloat sgenparams[] = { 1.0, 0.0, 0.0, 0.0 };
     GLint tile;
     gzFile f;
@@ -143,16 +143,18 @@ GLint fgObjLoad(char *path, struct fgCartesianPoint *ref, double *radius) {
            /* comment -- ignore */
        } else if ( line[0] == '\n' ) {
            /* empty line -- ignore */
+       } else if ( strncmp(line, "ref ", 4) == 0 ) {
+           /* reference point (center offset) */
+           sscanf(line, "ref %lf %lf %lf\n", &ref->x, &ref->y, &ref->z);
        } else if ( strncmp(line, "v ", 2) == 0 ) {
            /* node (vertex) */
            if ( ncount < MAXNODES ) {
                /* fgPrintf( FG_TERRAIN, FG_DEBUG, "vertex = %s", line); */
-               sscanf(line, "v %lf %lf %lf\n", &x, &y, &z);
-               nodes[ncount][0] = x;
-               nodes[ncount][1] = y;
-               nodes[ncount][2] = z;
+               sscanf(line, "v %lf %lf %lf\n", 
+                      &nodes[ncount][0], &nodes[ncount][1], &nodes[ncount][2]);
 
                /* first time through set min's and max'es */
+               /*
                if ( ncount == 1 ) {
                    xmin = x;
                    xmax = x;
@@ -161,14 +163,17 @@ GLint fgObjLoad(char *path, struct fgCartesianPoint *ref, double *radius) {
                    zmin = z;
                    zmax = z;
                }
+               */
     
                /* keep track of min/max vertex values */
+               /*
                if ( x < xmin ) xmin = x;
                if ( x > xmax ) xmax = x;
                if ( y < ymin ) ymin = y;
                if ( y > ymax ) ymax = y;
                if ( z < zmin ) zmin = z;
                if ( z > zmax ) zmax = z;               
+               */
 
                ncount++;
            } else {
@@ -395,19 +400,28 @@ GLint fgObjLoad(char *path, struct fgCartesianPoint *ref, double *radius) {
 
     gzclose(f);
 
-    /* reference point is the "center" */
+    /* reference point is the "center" (now included in input file) */
+    /*
     ref->x = (xmin + xmax) / 2.0;
     ref->y = (ymin + ymax) / 2.0;
     ref->z = (zmin + zmax) / 2.0;
+    */
 
     return(tile);
 }
 
 
 /* $Log$
-/* Revision 1.31  1998/04/25 15:09:57  curt
-/* Changed "r" to "rb" in gzopen() options.  This fixes bad behavior in win32.
+/* Revision 1.32  1998/04/27 03:30:13  curt
+/* Minor transformation adjustments to try to keep scenery tiles closer to
+/* (0, 0, 0)  GLfloats run out of precision at the distances we need to model
+/* the earth, but we can do a bunch of pre-transformations using double math
+/* and then cast to GLfloat once everything is close in where we have less
+/* precision problems.
 /*
+ * Revision 1.31  1998/04/25 15:09:57  curt
+ * Changed "r" to "rb" in gzopen() options.  This fixes bad behavior in win32.
+ *
  * Revision 1.30  1998/04/24 14:21:08  curt
  * Added "file.obj.gz" support.
  *

diff --git a/Scenery/tilemgr.cxx b/Scenery/tilemgr.cxx
index d100a902ee9ea767b4def924500aa00cc423e0b8..daeeed7a41c29e4d3de914fba9b0e43d981875e0 100644 (file)
--- a/Scenery/tilemgr.cxx
+++ b/Scenery/tilemgr.cxx
@@ -208,11 +208,11 @@ void fgTileMgrRender( void ) {
 
        if ( display_list >= 0 ) {
            xglPushMatrix();
-           /* xglTranslatef(local_ref.x - scenery.center.x,
+           xglTranslatef(local_ref.x - scenery.center.x,
                          local_ref.y - scenery.center.y,
-                         local_ref.z - scenery.center.z); */
-           xglTranslatef(-scenery.center.x, -scenery.center.y, 
-                         -scenery.center.z);
+                         local_ref.z - scenery.center.z);
+           /* xglTranslatef(-scenery.center.x, -scenery.center.y, 
+                         -scenery.center.z); */
            xglCallList(display_list);
            xglPopMatrix();
        }
@@ -221,9 +221,16 @@ void fgTileMgrRender( void ) {
 
 
 /* $Log$
-/* Revision 1.3  1998/04/25 22:06:32  curt
-/* Edited cvs log messages in source files ... bad bad bad!
+/* Revision 1.4  1998/04/27 03:30:14  curt
+/* Minor transformation adjustments to try to keep scenery tiles closer to
+/* (0, 0, 0)  GLfloats run out of precision at the distances we need to model
+/* the earth, but we can do a bunch of pre-transformations using double math
+/* and then cast to GLfloat once everything is close in where we have less
+/* precision problems.
 /*
+ * Revision 1.3  1998/04/25 22:06:32  curt
+ * Edited cvs log messages in source files ... bad bad bad!
+ *
  * Revision 1.2  1998/04/24 00:51:09  curt
  * Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
  * Tweaked the scenery file extentions to be "file.obj" (uncompressed)