Add two convenience methods for region point conversion

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/libei-private.h

@@ -279,9 +279,6 @@ ei_region_set_offset(struct ei_region *region, uint32_t x, uint32_t y);
 void
 ei_region_set_physical_scale(struct ei_region *region, double scale);
 
-bool
-ei_region_contains(struct ei_region *region, double x, double y);
-
 _printf_(6, 7) void
 ei_log_msg(struct ei *ei,
 	   enum ei_log_priority priority,

src/libei-region.c

@@ -79,9 +79,21 @@ ei_region_set_size(struct ei_region *region, uint32_t w, uint32_t h)
 	region->height = h;
 }
 
-bool
+_public_ bool
 ei_region_contains(struct ei_region *r, double x, double y)
 {
 	return (x >= r->x && x < r->x + r->width &&
 		y >= r->y && y < r->y + r->height);
 }
+
+_public_ bool
+ei_region_convert_point(struct ei_region *r, double *x, double *y)
+{
+	if (ei_region_contains(r, *x, *y)) {
+		*x -= r->x;
+		*y -= r->y;
+		return true;
+	}
+
+	return false;
+}

src/libei.h

@@ -825,6 +825,24 @@ ei_region_get_width(struct ei_region *region);
 uint32_t
 ei_region_get_height(struct ei_region *region);
 
+/**
+ * Return true if the point x/y (in desktop-wide coordinates) is within @a
+ * region.
+ */
+bool
+ei_region_contains(struct ei_region *region, double x, double y);
+
+/**
+ * Convert the point x/y in a desktop-wide coordinate system into the
+ * corresponding point relative to the offset of the given region.
+ * If the point is inside the region, this function returns true and @a x and @a
+ * y are set to the points with region offset subtracted.
+ * If the point is outside the region, this function returns false and @a x
+ * and @a y are left unmodified.
+ */
+bool
+ei_region_convert_point(struct ei_region *region, double *x, double *y);
+
 /**
  * Return the physical scale for this region. The default scale is 1.0.
  *