[libgis] Store "kids" in RoamTriangle only

[Andy Spencer <andys src gnome org>]

commit 84ce9447b38df46ae3adbdb1de9333feda77f68c
Author: Andy Spencer <andy753421 gmail com>
Date:   Mon Nov 1 03:24:46 2010 +0000

    Store "kids" in RoamTriangle only
    
    roam_diamond_merge uses:
    	self = parent_triangle[0];
    	base = parent_triangle[1];
    	kids = {self,base}.kids[0,1];

 src/roam.c |   57 +++++++++++++++++++++++----------------------------------
 src/roam.h |   19 ++++++++-----------
 2 files changed, 31 insertions(+), 45 deletions(-)
---
diff --git a/src/roam.c b/src/roam.c
index 4e5775f..2fe0acf 100644
--- a/src/roam.c
+++ b/src/roam.c
@@ -177,15 +177,17 @@ void roam_point_update_projection(RoamPoint *point, RoamView *view)
  *
  * 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 :
@@ -397,12 +399,14 @@ void roam_triangle_split(RoamTriangle *triangle, RoamSphere *sphere)
 	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);
@@ -420,9 +424,8 @@ void roam_triangle_split(RoamTriangle *triangle, RoamSphere *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);
 }
@@ -483,26 +486,11 @@ void roam_triangle_draw_normal(RoamTriangle *triangle)
  *
  * 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;
 }
 
@@ -556,10 +544,10 @@ void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere)
 	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;
@@ -663,7 +651,8 @@ RoamSphere *roam_sphere_new()
 		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]],
diff --git a/src/roam.h b/src/roam.h
index 11eb171..aec4b21 100644
--- a/src/roam.h
+++ b/src/roam.h
@@ -111,17 +111,18 @@ struct _RoamTriangle {
 	/* Left, base, and right neighbor triangles */
 	struct { RoamTriangle *l,*b,*r; } t;
 
-	RoamPoint *split;     /* Split point */
-	RoamDiamond *parent;  /* Parent diamond */
-	double norm[3];       /* Surface normal */
-	double error;         /* Screen space error */
+	RoamPoint *split;      /* Split point */
+	RoamDiamond *parent;   /* Parent diamond */
+	RoamTriangle *kids[2]; /* Higher-res triangles */
+	double norm[3];        /* Surface normal */
+	double error;          /* Screen space error */
 	GPQueueHandle handle;
 
 	/* For get_intersect */
 	struct { gdouble n,s,e,w; } edge;
-	RoamTriangle *kids[2];
 };
-RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r);
+RoamTriangle *roam_triangle_new(RoamPoint *l, RoamPoint *m, RoamPoint *r,
+		RoamDiamond *parent);
 void roam_triangle_free(RoamTriangle *triangle);
 void roam_triangle_add(RoamTriangle *triangle,
 		RoamTriangle *left, RoamTriangle *base, RoamTriangle *right,
@@ -148,16 +149,12 @@ void roam_triangle_draw_normal(RoamTriangle *triangle);
  */
 struct _RoamDiamond {
 	/*< private >*/
-	RoamTriangle *kids[4];    /* Child triangles */
 	RoamTriangle *parents[2]; /* Parent triangles */
 	double error;             /* Screen space error */
 	gboolean active;          /* For internal use */
 	GPQueueHandle handle;
 };
-RoamDiamond *roam_diamond_new(
-		RoamTriangle *parent0, RoamTriangle *parent1,
-		RoamTriangle *kid0, RoamTriangle *kid1,
-		RoamTriangle *kid2, RoamTriangle *kid3);
+RoamDiamond *roam_diamond_new(RoamTriangle *parent0, RoamTriangle *parent1);
 void roam_diamond_add(RoamDiamond *diamond, RoamSphere *sphere);
 void roam_diamond_remove(RoamDiamond *diamond, RoamSphere *sphere);
 void roam_diamond_merge(RoamDiamond *diamond, RoamSphere *sphere);