From b11fd4c409529141ee61781fc99aa2238f93e9ce Mon Sep 17 00:00:00 2001 From: Andy Spencer Date: Sat, 19 Dec 2009 22:59:49 +0000 Subject: [PATCH] Convert from xyz to lle as the main roam coordinates This keeps splits along latitude lines instead of along great circles. It is a little less accurate, but makes texture mapping much simpler, at least with Mercator projections. If we ever manage to get lle->xyz conversions done in an OpenGL shader, this should make the transition a little easier as well. Old Way New Way .-''/'''-. .-''/'''-. / __/_____ \ /.__/____..\ /'' | ''\ / | \ *..__*_____..* *..__*_____..* \ | / \ | / \ \ / \ \ / '-..\...-' '-..\...-' --- src/gis-util.c | 13 +++++++++++++ src/gis-util.h | 2 ++ src/roam.c | 50 ++++++++++++++++++++------------------------------ src/roam.h | 2 +- 4 files changed, 36 insertions(+), 31 deletions(-) diff --git a/src/gis-util.c b/src/gis-util.c index 3bd5246..19604fe 100644 --- a/src/gis-util.c +++ b/src/gis-util.c @@ -65,3 +65,16 @@ gdouble distd(gdouble *a, gdouble *b) (a[1]-b[1])*(a[1]-b[1]) + (a[2]-b[2])*(a[2]-b[2])); } + +gdouble lon_avg(gdouble a, gdouble b) +{ + gdouble diff = ABS(a-b); + gdouble avg = (a+b)/2; + if (diff > 180) { + if (avg >= 0) + avg -= 180; + else + avg += 180; + } + return avg; +} diff --git a/src/gis-util.h b/src/gis-util.h index a9f288a..c7e1f69 100644 --- a/src/gis-util.h +++ b/src/gis-util.h @@ -91,4 +91,6 @@ gdouble ll2m(gdouble lon_dist, gdouble lat); gdouble distd(gdouble *a, gdouble *b); +gdouble lon_avg(gdouble a, gdouble b); + #endif diff --git a/src/roam.c b/src/roam.c index 4bc294c..7f13182 100644 --- a/src/roam.c +++ b/src/roam.c @@ -46,17 +46,18 @@ static gint dia_cmp(RoamDiamond *a, RoamDiamond *b, gpointer data) else return 0; } + /************* * RoamPoint * *************/ -RoamPoint *roam_point_new(gdouble x, gdouble y, gdouble z) +RoamPoint *roam_point_new(gdouble lat, gdouble lon, gdouble elev) { RoamPoint *self = g_new0(RoamPoint, 1); - self->x = x; - self->y = y; - self->z = z; + self->lat = lat; + self->lon = lon; + self->elev = elev; /* For get_intersect */ - xyz2ll(x, y, z, &self->lat, &self->lon); + lle2xyz(lat, lon, elev, &self->x, &self->y, &self->z); return self; } RoamPoint *roam_point_dup(RoamPoint *self) @@ -93,13 +94,6 @@ void roam_point_update_height(RoamPoint *self) self->lat, self->lon, self->height_data); lle2xyz(self->lat, self->lon, elev, &self->x, &self->y, &self->z); - } else { - gdouble dist = sqrt(self->x * self->x + - self->y * self->y + - self->z * self->z); - self->x = self->x/dist * EARTH_R; - self->y = self->y/dist * EARTH_R; - self->z = self->z/dist * EARTH_R; } } void roam_point_update_projection(RoamPoint *self, RoamSphere *sphere) @@ -134,9 +128,11 @@ RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r) self->p.m = m; self->p.r = r; self->split = roam_point_new( - (l->x + r->x)/2, - (l->y + r->y)/2, - (l->z + r->z)/2); + (l->lat + r->lat)/2, + (ABS(l->lat) == 90 ? r->lon : + ABS(r->lat) == 90 ? l->lon : + lon_avg(l->lon, r->lon)), + (l->elev + r->elev)/2); /* TODO: Move this back to sphere, or actually use the nesting */ self->split->height_func = m->height_func; self->split->height_data = m->height_data; @@ -173,10 +169,7 @@ RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r) self->norm[2] /= total; /* Store bounding box, for get_intersect */ - RoamPoint *m1 = roam_point_new((l->x+m->x)/2, (l->y+m->y)/2, (l->z+m->z)/2); - RoamPoint *m2 = roam_point_new((m->x+r->x)/2, (m->y+r->y)/2, (m->z+r->z)/2); - RoamPoint *m3 = roam_point_new((r->x+l->x)/2, (r->y+l->y)/2, (r->z+l->z)/2); - RoamPoint *p[] = {l,m,r,m1,m2,m3}; + RoamPoint *p[] = {l,m,r}; self->edge.n = -90; self->edge.s = 90; self->edge.e = -180; self->edge.w = 180; gboolean maxed = FALSE; @@ -198,9 +191,6 @@ RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r) else self->edge.e = 180; } - g_free(m1); - g_free(m2); - g_free(m3); //g_message("roam_triangle_new: %p", self); return self; @@ -479,12 +469,12 @@ RoamSphere *roam_sphere_new() self->diamonds = g_pqueue_new((GCompareDataFunc)dia_cmp, NULL); RoamPoint *vertexes[] = { - roam_point_new( 0, 1, 0), // 0 - roam_point_new( 0,-1, 0), // 1 - roam_point_new( 0, 0, 1), // 2 - roam_point_new( 1, 0, 0), // 3 - roam_point_new( 0, 0,-1), // 4 - roam_point_new(-1, 0, 0), // 5 + roam_point_new( 90, 0, 0), // 0 (North) + roam_point_new(-90, 0, 0), // 1 (South) + roam_point_new( 0, 0, 0), // 2 (Europe/Africa) + roam_point_new( 0, 90, 0), // 3 (Asia,East) + roam_point_new( 0, 180, 0), // 4 (Pacific) + roam_point_new( 0, -90, 0), // 5 (Americas,West) }; int _triangles[][2][3] = { /*lv mv rv ln, bn, rn */ @@ -610,7 +600,7 @@ void roam_sphere_draw_normals(RoamSphere *self) g_debug("RoamSphere: draw_normal"); g_pqueue_foreach(self->triangles, (GFunc)roam_triangle_draw_normal, NULL); } -GList *_roam_sphere_get_leaves(RoamTriangle *tri, GList *list) +static GList *_roam_sphere_get_leaves(RoamTriangle *tri, GList *list) { if (tri->kids[0] && tri->kids[1]) { list = _roam_sphere_get_leaves(tri->kids[0], list); @@ -620,7 +610,7 @@ GList *_roam_sphere_get_leaves(RoamTriangle *tri, GList *list) return g_list_append(list, tri); } } -GList *_roam_sphere_get_intersect_rec(RoamTriangle *tri, GList *list, +static GList *_roam_sphere_get_intersect_rec(RoamTriangle *tri, GList *list, gdouble n, gdouble s, gdouble e, gdouble w) { gdouble tn = tri->edge.n; diff --git a/src/roam.h b/src/roam.h index 3845700..815390f 100644 --- a/src/roam.h +++ b/src/roam.h @@ -48,7 +48,7 @@ struct _RoamPoint { gdouble norm[3]; // Vertex normal /* For get_intersect */ - gdouble lat, lon; + gdouble lat, lon, elev; /* For terrain */ RoamHeightFunc height_func; -- 2.43.2