X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=src%2Froam.c;h=d8bff628b33f939151e1def1c2c1f069a76b17d9;hb=5d4daa2b86d30c77c9828447ca1828a45713b5d6;hp=2fe0acfb65a0b9a58883790759b5e6530e0d5138;hpb=84ce9447b38df46ae3adbdb1de9333feda77f68c;p=grits

diff --git a/src/roam.c b/src/roam.c
index 2fe0acf..d8bff62 100644
--- a/src/roam.c
+++ b/src/roam.c
@@ -21,8 +21,8 @@
  *
  * A spherical version of the Realtime Optimally-Adapting Meshes (ROAM)
  * algorithm is use for drawing the surface of the planet. ROAM provide a
- * continuous level-of-detail mesh of the planet which is used by #GisOpenGL
- * when drawing surface textures for GisTiles.
+ * continuous level-of-detail mesh of the planet which is used by #GritsOpenGL
+ * when drawing surface textures for GritsTiles.
  *
  * This implementation of the ROAM algorithm is based on an octahedron as the
  * base model.
@@ -35,7 +35,7 @@
 #include <GL/glu.h>
 
 #include "gpqueue.h"
-#include "gis-util.h"
+#include "grits-util.h"
 #include "roam.h"
 
 /*
@@ -206,27 +206,10 @@ RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r,
 	//		triangle->split->lat, l->lat);
 
 	/* Update normal */
-	double pa[3];
-	double pb[3];
-	pa[0] = triangle->p.l->x - triangle->p.m->x;
-	pa[1] = triangle->p.l->y - triangle->p.m->y;
-	pa[2] = triangle->p.l->z - triangle->p.m->z;
-
-	pb[0] = triangle->p.r->x - triangle->p.m->x;
-	pb[1] = triangle->p.r->y - triangle->p.m->y;
-	pb[2] = triangle->p.r->z - triangle->p.m->z;
-
-	triangle->norm[0] = pa[1] * pb[2] - pa[2] * pb[1];
-	triangle->norm[1] = pa[2] * pb[0] - pa[0] * pb[2];
-	triangle->norm[2] = pa[0] * pb[1] - pa[1] * pb[0];
-
-	double total = sqrt(triangle->norm[0] * triangle->norm[0] +
-	                    triangle->norm[1] * triangle->norm[1] +
-	                    triangle->norm[2] * triangle->norm[2]);
-
-	triangle->norm[0] /= total;
-	triangle->norm[1] /= total;
-	triangle->norm[2] /= total;
+	crossd3((gdouble*)triangle->p.l,
+	        (gdouble*)triangle->p.m,
+	        (gdouble*)triangle->p.r, triangle->norm);
+	normd(triangle->norm);
 
 	/* Store bounding box, for get_intersect */
 	RoamPoint *p[] = {l,m,r};
@@ -313,12 +296,12 @@ void roam_triangle_remove(RoamTriangle *triangle, RoamSphere *sphere)
 	g_pqueue_remove(sphere->triangles, triangle->handle);
 }
 
-static void roam_triangle_sync_neighbors(RoamTriangle *new, RoamTriangle *old, RoamTriangle *neigh)
+/* (neight->t.? == old) = new */
+static void roam_triangle_sync_neighbors(RoamTriangle *neigh, RoamTriangle *old, RoamTriangle *new)
 {
 	if      (neigh->t.l == old) neigh->t.l = new;
 	else if (neigh->t.b == old) neigh->t.b = new;
 	else if (neigh->t.r == old) neigh->t.r = new;
-	else g_assert_not_reached();
 }
 
 static gboolean roam_triangle_visible(RoamTriangle *triangle, RoamSphere *sphere)
@@ -337,6 +320,20 @@ static gboolean roam_triangle_visible(RoamTriangle *triangle, RoamSphere *sphere
 	         l->pz < 1 && m->pz < 1 && r->pz < 1;
 }
 
+static gboolean roam_triangle_backface(RoamTriangle *triangle, RoamSphere *sphere)
+{
+	RoamPoint *l = triangle->p.l;
+	RoamPoint *m = triangle->p.m;
+	RoamPoint *r = triangle->p.r;
+	roam_point_update_projection(l, sphere->view);
+	roam_point_update_projection(m, sphere->view);
+	roam_point_update_projection(r, sphere->view);
+	double size = -( l->px * (m->py - r->py) +
+			 m->px * (r->py - l->py) +
+			 r->px * (l->py - m->py) ) / 2.0;
+	return size < 0;
+}
+
 /**
  * roam_triangle_update_errors:
  * @triangle: the triangle
@@ -374,6 +371,12 @@ void roam_triangle_update_errors(RoamTriangle *triangle, RoamSphere *sphere)
 
 		/* Size < 0 == backface */
 		triangle->error *= size;
+
+		/* Give some preference to "edge" faces */
+		if (roam_triangle_backface(triangle->t.l, sphere) ||
+		    roam_triangle_backface(triangle->t.b, sphere) ||
+		    roam_triangle_backface(triangle->t.r, sphere))
+			triangle->error *= 50;
 	}
 }
 
@@ -414,10 +417,10 @@ void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere)
 	roam_triangle_add(bl, br, b->t.l, sr, sphere);
 	roam_triangle_add(br, sl, b->t.r, bl, sphere);
 
-	roam_triangle_sync_neighbors(sl, s, s->t.l);
-	roam_triangle_sync_neighbors(sr, s, s->t.r);
-	roam_triangle_sync_neighbors(bl, b, b->t.l);
-	roam_triangle_sync_neighbors(br, b, b->t.r);
+	roam_triangle_sync_neighbors(s->t.l, s, sl);
+	roam_triangle_sync_neighbors(s->t.r, s, sr);
+	roam_triangle_sync_neighbors(b->t.l, b, bl);
+	roam_triangle_sync_neighbors(b->t.r, b, br);
 
 	/* Remove old triangles */
 	roam_triangle_remove(s, sphere);
@@ -553,13 +556,18 @@ void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere)
 	b->kids[0] = b->kids[1] = NULL;
 
 	/* Add original triangles */
+	roam_triangle_sync_neighbors(s->t.l, sl, s);
+	roam_triangle_sync_neighbors(s->t.r, sr, s);
+	roam_triangle_sync_neighbors(b->t.l, bl, b);
+	roam_triangle_sync_neighbors(b->t.r, br, b);
+
 	roam_triangle_add(s, sl->t.b, b, sr->t.b, sphere);
 	roam_triangle_add(b, bl->t.b, s, br->t.b, sphere);
 
-	roam_triangle_sync_neighbors(s, sl, sl->t.b);
-	roam_triangle_sync_neighbors(s, sr, sr->t.b);
-	roam_triangle_sync_neighbors(b, bl, bl->t.b);
-	roam_triangle_sync_neighbors(b, br, br->t.b);
+	roam_triangle_sync_neighbors(sl->t.b, sl, s);
+	roam_triangle_sync_neighbors(sr->t.b, sr, s);
+	roam_triangle_sync_neighbors(bl->t.b, bl, b);
+	roam_triangle_sync_neighbors(br->t.b, br, b);
 
 	/* Remove child triangles */
 	roam_triangle_remove(sl, sphere);
@@ -752,6 +760,7 @@ void roam_sphere_merge_one(RoamSphere *sphere)
 gint roam_sphere_split_merge(RoamSphere *sphere)
 {
 	gint iters = 0, max_iters = 500;
+	//gint target = 20000;
 	//gint target = 4000;
 	gint target = 2000;
 	//gint target = 500;