libcamera: Add transpose() function to size

Add a transpose() function to size that applies the
Transformation::Transpose operation in the size. This is useful when
handling orientation adjustments.

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/geometry.h

@@ -108,6 +108,12 @@ public:
 		return *this;
 	}
 
+	Size &transpose()
+	{
+		std::swap(width, height);
+		return *this;
+	}
+
 	[[nodiscard]] constexpr Size alignedDownTo(unsigned int hAlignment,
 						   unsigned int vAlignment) const
 	{

src/libcamera/geometry.cpp

@@ -209,6 +209,16 @@ std::string Size::toString() const
  * \return A reference to this object
  */
 
+/**
+ * \fn Size::transpose()
+ * \brief Transpose the size in place
+ *
+ * This function swaps width and height of this size. This effectively applies
+ * the \a Transform::Transpose transformation on this size.
+ *
+ * \return A reference to this object
+ */
+
 /**
  * \fn Size::alignedDownTo(unsigned int hAlignment, unsigned int vAlignment)
  * \brief Align the size down horizontally and vertically

test/geometry.cpp

@@ -203,6 +203,11 @@ protected:
 			return TestFail;
 		}
 
+		if (Size(200, 50).transpose() != Size(50, 200)) {
+			cout << "Size::transpose() test failed" << endl;
+			return TestFail;
+		}
+
 		/* Aspect ratio tests */
 		if (Size(0, 0).boundedToAspectRatio(Size(4, 3)) != Size(0, 0) ||
 		    Size(1920, 1440).boundedToAspectRatio(Size(16, 9)) != Size(1920, 1080) ||