libcamera: geometry: Provide in-place versions of the Size helpers

Add alignDownTo(), alignUpTo(), boundTo() and expandTo() helper
functions to the Size class. These are in-place versions of the existing
alignedDownTo(), alignedUpTo(), boundedTo() and expandedTo() functions.

The new helpers return a reference to the size, to allow chaining the
functions. One can thus write

	size.alignDownTo(16, 16).alignUpTo(32, 32)
	    .boundTo({ 40, 80 }).expandTo({ 16, 80 });

instead of

	size.alignDownTo(16, 16);
	size.alignUpTo(32, 32);
	size.boundTo({ 40, 80 });
	size.expandTo({ 16, 80 });

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/geometry.h

@@ -32,6 +32,34 @@ public:
 	bool isNull() const { return !width && !height; }
 	const std::string toString() const;
 
+	Size &alignDownTo(unsigned int hAlignment, unsigned int vAlignment)
+	{
+		width = width / hAlignment * hAlignment;
+		height = height / vAlignment * vAlignment;
+		return *this;
+	}
+
+	Size &alignUpTo(unsigned int hAlignment, unsigned int vAlignment)
+	{
+		width = (width + hAlignment - 1) / hAlignment * hAlignment;
+		height = (height + vAlignment - 1) / vAlignment * vAlignment;
+		return *this;
+	}
+
+	Size &boundTo(const Size &bound)
+	{
+		width = std::min(width, bound.width);
+		height = std::min(height, bound.height);
+		return *this;
+	}
+
+	Size &expandTo(const Size &expand)
+	{
+		width = std::max(width, expand.width);
+		height = std::max(height, expand.height);
+		return *this;
+	}
+
 	constexpr Size alignedDownTo(unsigned int hAlignment,
 				     unsigned int vAlignment) const
 	{

src/libcamera/geometry.cpp

@@ -61,6 +61,52 @@ const std::string Size::toString() const
 	return std::to_string(width) + "x" + std::to_string(height);
 }
 
+/**
+ * \fn Size::alignDownTo(unsigned int hAlignment, unsigned int vAlignment)
+ * \brief Align the size down horizontally and vertically in place
+ * \param[in] hAlignment Horizontal alignment
+ * \param[in] vAlignment Vertical alignment
+ *
+ * This functions rounds the width and height down to the nearest multiple of
+ * \a hAlignment and \a vAlignment respectively.
+ *
+ * \return A reference to this object
+ */
+
+/**
+ * \fn Size::alignUpTo(unsigned int hAlignment, unsigned int vAlignment)
+ * \brief Align the size up horizontally and vertically in place
+ * \param[in] hAlignment Horizontal alignment
+ * \param[in] vAlignment Vertical alignment
+ *
+ * This functions rounds the width and height up to the nearest multiple of
+ * \a hAlignment and \a vAlignment respectively.
+ *
+ * \return A reference to this object
+ */
+
+/**
+ * \fn Size::boundTo(const Size &bound)
+ * \brief Bound the size to \a bound in place
+ * \param[in] bound The maximum size
+ *
+ * This function sets the width and height to the minimum of this size and the
+ * \a bound size.
+ *
+ * \return A reference to this object
+ */
+
+/**
+ * \fn Size::expandTo(const Size &expand)
+ * \brief Expand the size to \a expand
+ * \param[in] expand The minimum size
+ *
+ * This function sets the width and height to the maximum of this size and the
+ * \a expand 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

@@ -46,6 +46,40 @@ protected:
 			return TestFail;
 		}
 
+		/* Test alignDownTo(), alignUpTo(), boundTo() and expandTo() */
+		Size s(50, 50);
+
+		s.alignDownTo(16, 16);
+		if (s != Size(48, 48)) {
+			cout << "Size::alignDownTo() test failed" << endl;
+			return TestFail;
+		}
+
+		s.alignUpTo(32, 32);
+		if (s != Size(64, 64)) {
+			cout << "Size::alignUpTo() test failed" << endl;
+			return TestFail;
+		}
+
+		s.boundTo({ 40, 40 });
+		if (s != Size(40, 40)) {
+			cout << "Size::boundTo() test failed" << endl;
+			return TestFail;
+		}
+
+		s.expandTo({ 50, 50 });
+		if (s != Size(50, 50)) {
+			cout << "Size::expandTo() test failed" << endl;
+			return TestFail;
+		}
+
+		s.alignDownTo(16, 16).alignUpTo(32, 32)
+		 .boundTo({ 40, 80 }).expandTo({ 16, 80 });
+		if (s != Size(40, 80)) {
+			cout << "Size chained in-place modifiers test failed" << endl;
+			return TestFail;
+		}
+
 		/* Test alignedDownTo(), alignedUpTo(), boundedTo() and expandedTo() */
 		if (Size(0, 0).alignedDownTo(16, 8) != Size(0, 0) ||
 		    Size(1, 1).alignedDownTo(16, 8) != Size(0, 0) ||