libcamera: geometry: Add comparison operators to geometry classes

Add equality and inequality comparison operators for the Rectangle, Size
and SizeRange classes.

For the Size class, also add ordering operators. Sizes are first
compared on combined width and height, then on area, and finally on
width only to achieve a stable ordering.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 98 insertions, 0 deletions

diff --git a/src/libcamera/geometry.cpp b/src/libcamera/geometry.cpp
index c1c7daed..d14c925a 100644
--- a/src/libcamera/geometry.cpp
+++ b/src/libcamera/geometry.cpp
@@ -6,6 +6,7 @@
  */
 
 #include <sstream>
+#include <stdint.h>
 
 #include <libcamera/geometry.h>
 
@@ -63,6 +64,22 @@ const std::string Rectangle::toString() const
 }
 
 /**
+ * \brief Compare rectangles for equality
+ * \return True if the two rectangles are equal, false otherwise
+ */
+bool operator==(const Rectangle &lhs, const Rectangle &rhs)
+{
+	return lhs.x == rhs.x && lhs.y == rhs.y &&
+	       lhs.w == rhs.w && lhs.h == rhs.h;
+}
+
+/**
+ * \fn bool operator!=(const Rectangle &lhs, const Rectangle &rhs)
+ * \brief Compare rectangles for inequality
+ * \return True if the two rectangles are not equal, false otherwise
+ */
+
+/**
  * \struct Size
  * \brief Describe a two-dimensional size
  *
@@ -92,6 +109,72 @@ const std::string Rectangle::toString() const
  */
 
 /**
+ * \brief Compare sizes for equality
+ * \return True if the two sizes are equal, false otherwise
+ */
+bool operator==(const Size &lhs, const Size &rhs)
+{
+	return lhs.width == rhs.width && lhs.height == rhs.height;
+}
+
+/**
+ * \brief Compare sizes for smaller than order
+ *
+ * Sizes are compared on three criteria, in the following order.
+ *
+ * - A size with smaller width and smaller height is smaller.
+ * - A size with smaller area is smaller.
+ * - A size with smaller width is smaller.
+ *
+ * \return True if \a lhs is smaller than \a rhs, false otherwise
+ */
+bool operator<(const Size &lhs, const Size &rhs)
+{
+	if (lhs.width < rhs.width && lhs.height < rhs.height)
+		return true;
+	else if (lhs.width >= rhs.width && lhs.height >= rhs.height)
+		return false;
+
+	uint64_t larea = static_cast<uint64_t>(lhs.width) *
+			 static_cast<uint64_t>(lhs.height);
+	uint64_t rarea = static_cast<uint64_t>(rhs.width) *
+			 static_cast<uint64_t>(rhs.height);
+	if (larea < rarea)
+		return true;
+	else if (larea > rarea)
+		return false;
+
+	return lhs.width < rhs.width;
+}
+
+/**
+ * \fn bool operator!=(const Size &lhs, const Size &rhs)
+ * \brief Compare sizes for inequality
+ * \return True if the two sizes are not equal, false otherwise
+ */
+
+/**
+ * \fn bool operator<=(const Size &lhs, const Size &rhs)
+ * \brief Compare sizes for smaller than or equal to order
+ * \return True if \a lhs is smaller than or equal to \a rhs, false otherwise
+ * \sa bool operator<(const Size &lhs, const Size &rhs)
+ */
+
+/**
+ * \fn bool operator>(const Size &lhs, const Size &rhs)
+ * \brief Compare sizes for greater than order
+ * \return True if \a lhs is greater than \a rhs, false otherwise
+ * \sa bool operator<(const Size &lhs, const Size &rhs)
+ */
+
+/**
+ * \fn bool operator>=(const Size &lhs, const Size &rhs)
+ * \brief Compare sizes for greater than or equal to order
+ * \return True if \a lhs is greater than or equal to \a rhs, false otherwise
+ * \sa bool operator<(const Size &lhs, const Size &rhs)
+ */
+
+/**
  * \struct SizeRange
  * \brief Describe a range of sizes
  *
@@ -124,4 +207,19 @@ const std::string Rectangle::toString() const
  * \brief The maximum size
  */
 
+/**
+ * \brief Compare size ranges for equality
+ * \return True if the two size ranges are equal, false otherwise
+ */
+bool operator==(const SizeRange &lhs, const SizeRange &rhs)
+{
+	return lhs.min == rhs.min && lhs.max == rhs.max;
+}
+
+/**
+ * \fn bool operator!=(const SizeRange &lhs, const SizeRange &rhs)
+ * \brief Compare size ranges for inequality
+ * \return True if the two size ranges are not equal, false otherwise
+ */
+
 } /* namespace libcamera */