Index: uspace/lib/gfx/src/coord.c
===================================================================
--- uspace/lib/gfx/src/coord.c	(revision 5271e4ce7c269901a92de4f2e7b3ed4926eec5f2)
+++ uspace/lib/gfx/src/coord.c	(revision 0ee3157bf2b87f9bff38e12dfecd8d9b3ec96139)
@@ -39,4 +39,25 @@
 #include <stddef.h>
 
+/** Divide @a a by @a b and round towards negative numbers.
+ *
+ * Regular integer division always rounds towards zero. This is not useful
+ * e.g. for scaling down, where we always need to round towards negative
+ * numbers.
+ *
+ * @param a Dividend
+ * @param b Divisor
+ * @return Quotient
+ */
+gfx_coord_t gfx_coord_div_rneg(gfx_coord_t a, gfx_coord_t b)
+{
+	if ((a > 0 && b > 0) || (a < 0 && b < 0)) {
+		/* Result is non-negative, round towards zero */
+		return a / b;
+	} else {
+		/* Result is negative, round away from zero */
+		return (a - b + 1) / b;
+	}
+}
+
 /** Add two vectors.
  *