*
* 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.
#include <GL/glu.h>
#include "gpqueue.h"
-#include "gis-util.h"
+#include "grits-util.h"
#include "roam.h"
/*
*
* Returns: the new triangle
*/
-RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r)
+RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r,
+ RoamDiamond *parent)
{
RoamTriangle *triangle = g_new0(RoamTriangle, 1);
- triangle->error = 0;
- triangle->p.l = l;
- triangle->p.m = m;
- triangle->p.r = r;
- triangle->split = roam_point_new(
+ triangle->error = 0;
+ triangle->p.l = l;
+ triangle->p.m = m;
+ triangle->p.r = r;
+ triangle->parent = parent;
+ triangle->split = roam_point_new(
(l->lat + r->lat)/2,
(ABS(l->lat) == 90 ? r->lon :
ABS(r->lat) == 90 ? l->lon :
// 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};
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)
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
/* 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 *= 500;
}
}
RoamTriangle *s = triangle; // Self
RoamTriangle *b = triangle->t.b; // Base
+ RoamDiamond *dia = roam_diamond_new(s, b);
+
/* Add new triangles */
RoamPoint *mid = triangle->split;
- RoamTriangle *sl = s->kids[0] = roam_triangle_new(s->p.m, mid, s->p.l); // Self Left
- RoamTriangle *sr = s->kids[1] = roam_triangle_new(s->p.r, mid, s->p.m); // Self Right
- RoamTriangle *bl = b->kids[0] = roam_triangle_new(b->p.m, mid, b->p.l); // Base Left
- RoamTriangle *br = b->kids[1] = roam_triangle_new(b->p.r, mid, b->p.m); // Base Right
+ RoamTriangle *sl = s->kids[0] = roam_triangle_new(s->p.m, mid, s->p.l, dia); // Self Left
+ RoamTriangle *sr = s->kids[1] = roam_triangle_new(s->p.r, mid, s->p.m, dia); // Self Right
+ RoamTriangle *bl = b->kids[0] = roam_triangle_new(b->p.m, mid, b->p.l, dia); // Base Left
+ RoamTriangle *br = b->kids[1] = roam_triangle_new(b->p.r, mid, b->p.m, dia); // Base Right
/* triangle,l, base, r, sphere */
roam_triangle_add(sl, sr, s->t.l, br, 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);
roam_triangle_remove(b, sphere);
/* Add/Remove diamonds */
- RoamDiamond *diamond = roam_diamond_new(s, b, sl, sr, bl, br);
- roam_diamond_update_errors(diamond, sphere);
- roam_diamond_add(diamond, sphere);
+ roam_diamond_update_errors(dia, sphere);
+ roam_diamond_add(dia, sphere);
roam_diamond_remove(s->parent, sphere);
roam_diamond_remove(b->parent, sphere);
}
*
* Returns: the new diamond
*/
-RoamDiamond *roam_diamond_new(
- RoamTriangle *parent0, RoamTriangle *parent1,
- RoamTriangle *kid0, RoamTriangle *kid1,
- RoamTriangle *kid2, RoamTriangle *kid3)
+RoamDiamond *roam_diamond_new(RoamTriangle *parent0, RoamTriangle *parent1)
{
RoamDiamond *diamond = g_new0(RoamDiamond, 1);
-
- diamond->kids[0] = kid0;
- diamond->kids[1] = kid1;
- diamond->kids[2] = kid2;
- diamond->kids[3] = kid3;
-
- kid0->parent = diamond;
- kid1->parent = diamond;
- kid2->parent = diamond;
- kid3->parent = diamond;
-
diamond->parents[0] = parent0;
diamond->parents[1] = parent1;
-
return diamond;
}
RoamTriangle *s = diamond->parents[0]; // Self
RoamTriangle *b = diamond->parents[1]; // Base
- RoamTriangle *sl = diamond->kids[0];
- RoamTriangle *sr = diamond->kids[1];
- RoamTriangle *bl = diamond->kids[2];
- RoamTriangle *br = diamond->kids[3];
+ RoamTriangle *sl = s->kids[0];
+ RoamTriangle *sr = s->kids[1];
+ RoamTriangle *bl = b->kids[0];
+ RoamTriangle *br = b->kids[1];
s->kids[0] = s->kids[1] = NULL;
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);
sphere->roots[i] = roam_triangle_new(
vertexes[_triangles[i][0][0]],
vertexes[_triangles[i][0][1]],
- vertexes[_triangles[i][0][2]]);
+ vertexes[_triangles[i][0][2]],
+ NULL);
for (int i = 0; i < 8; i++)
roam_triangle_add(sphere->roots[i],
sphere->roots[_triangles[i][1][0]],