move noOverlapPositions to geo

1 files changed, 27 insertions, 1 deletions

diff --git a/geo.c b/geo.c
index 5bf7e39..0f70eaf 100644
--- a/geo.c
+++ b/geo.c
@@ -1,5 +1,6 @@
-#include <stddef.h>
+#include <stdlib.h>
 
+#include "sysfatal.h"
 #include "balls.h"
 
 int
@@ -22,3 +23,28 @@ insetRect(Rectangle r, float n) {
 
 	return r;
 }
+
+/* Generate n circle coordinates within bounds such that no circles overlap. */
+Vector *
+noOverlapPositions(int n, Rectangle bounds, float radius) {
+	Vector *ps;
+	Rectangle r;
+	int i, j;
+
+	if ((ps = malloc(n*sizeof(Vector))) == NULL)
+		sysfatal("Failed to allocate position array.\n");
+
+	r = insetRect(bounds, radius);
+	for (i = 0; i < n; i++) {
+		ps[i] = randPtInRect(r);
+		for (j = 0; j < i; j++)
+			if (isCollision(ps[j], radius, ps[i], radius))
+				break;
+		if (j < i) { /* Overlapping. */
+			i--;
+			continue;
+		}
+	}
+
+	return ps;
+}
\ No newline at end of file