Added Surface methods centerOnX() and centerOnY().

svn-id: r43051

2 files changed, 45 insertions, 1 deletions

diff --git a/engines/draci/surface.cpp b/engines/draci/surface.cpp
index 636ec0c4ac..e5fb18dda0 100644
--- a/engines/draci/surface.cpp
+++ b/engines/draci/surface.cpp
@@ -118,7 +118,7 @@ void Surface::setTransparentColour(uint colour) {
 }
 
 /**
- * @ brief Fills the surface with the specified colour
+ * @brief Fills the surface with the specified colour
  */
 void Surface::fill(uint colour) {
 	byte *ptr = (byte *)getBasePtr(0, 0);
@@ -126,4 +126,46 @@ void Surface::fill(uint colour) {
 	memset(ptr, colour, w * h);
 }
 
+/**
+ * @brief Calculates horizontal center of an object
+ *
+ * @param x 	The x coordinate of the center
+ * @param width The width of the object to be centered (in pixels)
+ *
+ * @return The centered x coordinate
+ */
+uint Surface::centerOnX(uint x, uint width) {
+
+	int newX = x - width / 2;
+
+	if (newX < 0)
+		newX = 0;
+
+	if (newX + width >= (uint)w - 1)
+		newX = (w - 1) - width;
+
+	return newX;
+}
+
+/**
+ * @brief Calculates vertical center of an object
+ *
+ * @param y 	The y coordinate of the center
+ * @param height The height of the object to be centered (in pixels)
+ *
+ * @return The centered y coordinate
+ */
+uint Surface::centerOnY(uint y, uint height) {
+	
+	int newY = y - height / 2;
+	
+	if (newY < 0)
+		newY = 0;
+
+	if (newY + height >= (uint)h - 1)
+		newY = (h - 1) - height;
+
+	return newY;
+}
+
 } // End of namespace Draci
diff --git a/engines/draci/surface.h b/engines/draci/surface.h
index db564ec2e5..1c7022ceff 100644
--- a/engines/draci/surface.h
+++ b/engines/draci/surface.h
@@ -45,6 +45,8 @@ public:
 	uint getTransparentColour();
 	void setTransparentColour(uint colour);
 	void fill(uint colour);
+	uint centerOnY(uint y, uint height);
+	uint centerOnX(uint x, uint width);
 
 private:
 	/** The current transparent colour of the surface. See getTransparentColour() and