geometry utilities

src/util.js

@@ -196,6 +196,53 @@ function isPrimaryMouseButton(ev) {
 }
 
 
+/* Geometry
+----------------------------------------------------------------------------------------------------------------------*/
+
+
+// Returns a new rectangle that is the intersection of the two rectangles. If they don't intersect, returns false
+function intersectRects(rect1, rect2) {
+	var res = {
+		left: Math.max(rect1.left, rect2.left),
+		right: Math.min(rect1.right, rect2.right),
+		top: Math.max(rect1.top, rect2.top),
+		bottom: Math.min(rect1.bottom, rect2.bottom)
+	};
+
+	if (res.left < res.right && res.top < res.bottom) {
+		return res;
+	}
+	return false;
+}
+
+
+// Returns a new point that will have been moved to reside within the given rectangle
+function constrainPoint(point, rect) {
+	return {
+		left: Math.min(Math.max(point.left, rect.left), rect.right),
+		top: Math.min(Math.max(point.top, rect.top), rect.bottom)
+	};
+}
+
+
+// Returns a point that is the center of the given rectangle
+function getRectCenter(rect) {
+	return {
+		left: (rect.left + rect.right) / 2,
+		top: (rect.top + rect.bottom) / 2
+	};
+}
+
+
+// Subtracts point2's coordinates from point1's coordinates, returning a delta
+function diffPoints(point1, point2) {
+	return {
+		left: point1.left - point2.left,
+		top: point1.top - point2.top
+	};
+}
+
+
 /* FullCalendar-specific Misc Utilities
 ----------------------------------------------------------------------------------------------------------------------*/