11 files changed, 385 insertions, 0 deletions

diff --git a/src/util/pick_convert.c b/src/util/pick_convert.c
new file mode 100644
index 0000000..baafcfb
--- a/dev/null
+++ b/src/util/pick_convert.c
@@ -0,0 +1,50 @@
+#include "pick_convert.h"
+
+/*
+ * Width and height of a selection box about a single-click selection.
+ */
+#define N 3.0
+
+void pick_convert (int select_x, int select_y, int x, int y,
+                   double *c_x, double *c_y, double *w, double *h)
+{
+  /*
+   * Calculate X and the width.
+   */
+  if (x > select_x)
+    {
+      *c_x = (x - select_x) / 2.0 + select_x;
+      *w = x - select_x;      
+    }
+  else if (x < select_x)
+    {
+      *c_x = (select_x - x) / 2.0 + x;
+      *w = select_x - x;
+    }
+  else
+    {
+      *c_x = x;
+      *w = N;
+    }
+
+  /*
+   * Calculate Y and the width.
+   */
+  if (y > select_y)
+    {
+      *c_y = (y - select_y) / 2.0 + select_y;
+      *h = y - select_y;
+    }
+  else if (y < select_y)
+    {
+      *c_y = (select_y - y) / 2.0 + y;
+      *h = select_y - y;
+    }
+  else
+    {
+      *c_y = y;
+      *h = N;
+    }
+
+  return;
+}