fix long standing bug in label positioning code

3 files changed, 41 insertions, 5 deletions

diff --git a/src/GipfelWidget.cxx b/src/GipfelWidget.cxx
index c72cb39..f0403cf 100644
--- a/src/GipfelWidget.cxx
+++ b/src/GipfelWidget.cxx
@@ -344,6 +344,7 @@ GipfelWidget::set_labels(Hills *v) {
 
 	for (int i = 0; i < v->get_num(); i++) {
 		Hill *m = v->get(i);
+		Hills colliding;
 
 		if (m->flags & (Hill::DUPLICATE | Hill::TRACK_POINT))
 			continue;
@@ -363,13 +364,22 @@ GipfelWidget::set_labels(Hills *v) {
 			if (!show_hidden && (n->flags & Hill::HIDDEN))
 				continue;
 
+			if (overlap(m->x, m->label_x,
+					n->x - CROSS_SIZE, n->label_x + CROSS_SIZE))
+				colliding.add(n);
+		}
+
+		colliding.sort_label_y();
+
+		for (int j = 0; j < colliding.get_num(); j++) {
+			Hill *n = colliding.get(j);
+
 			// Check for overlapping labels and
 			// overlaps between labels and peak markers
-			if ((overlap(m->x, m->label_x, n->x, n->label_x) &&
-					overlap(m->y + m->label_y - height, height,
-						n->y + n->label_y - height, height)) ||
-				(overlap(m->x, m->label_x, n->x - 2, 4) &&
-				 overlap(m->y + m->label_y - height, height, n->y - 2, 4))) {
+			if (overlap(m->y + m->label_y - height, height,
+					n->y + n->label_y - height, height) ||
+				overlap(m->y + m->label_y - height,
+					height, n->y - CROSS_SIZE, 2 * CROSS_SIZE)) {
 
 				m->label_y = (int) rint(n->y + n->label_y - m->y - height - 2);
 			}
diff --git a/src/Hill.H b/src/Hill.H
index fb02feb..b4ced70 100644
--- a/src/Hill.H
+++ b/src/Hill.H
@@ -41,6 +41,12 @@ class Hills {
 		Hill **m;
 
 	public:
+		typedef enum {
+			SORT_PHI,
+			SORT_NAME,
+			SORT_LABEL_Y
+		} SortType;
+	
 		Hills();
 		Hills(const Hills *h);
 		~Hills();
@@ -52,6 +58,7 @@ class Hills {
 		void add(Hills *h);
 		void sort_phi();
 		void sort_name();
+		void sort_label_y();
 		void sort();
 		void clear();
 		void clobber();
diff --git a/src/Hill.cxx b/src/Hill.cxx
index f4ba112..9056d2f 100644
--- a/src/Hill.cxx
+++ b/src/Hill.cxx
@@ -225,6 +225,17 @@ comp_mountains_name(const void *n1, const void *n2) {
 	}
 }
 
+static int
+comp_mountains_label_y(const void *n1, const void *n2) {
+	Hill *m1 = *(Hill **)n1;
+	Hill *m2 = *(Hill **)n2;
+
+	if (m1 && m2)
+		return (m2->y + m2->label_y) - (m1->y + m1->label_y);
+	else
+		return 0;
+}
+
 void
 Hills::sort() {
 	if (!m)
@@ -250,6 +261,14 @@ Hills::sort_name() {
 }
 
 void
+Hills::sort_label_y() {
+	if (!m)
+		return;
+
+	qsort(m, num, sizeof(Hill *), comp_mountains_label_y);
+}
+
+void
 Hills::clear() {
 	if (m) {
 		free(m);