libcamera: geometry: Add Size members to grown or shrink by a margin

Add four new member functions to the Size class (two in-place and two
const) to grow and shrink a Size by given margins.

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

1 files changed, 30 insertions, 0 deletions

diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h
index fdd1b467..fa7ae7bc 100644
--- a/include/libcamera/geometry.h
+++ b/include/libcamera/geometry.h
@@ -94,6 +94,20 @@ public:
 		return *this;
 	}
 
+	Size &growBy(const Size &margins)
+	{
+		width += margins.width;
+		height += margins.height;
+		return *this;
+	}
+
+	Size &shrinkBy(const Size &margins)
+	{
+		width = width > margins.width ? width - margins.width : 0;
+		height = height > margins.height ? height - margins.height : 0;
+		return *this;
+	}
+
 	__nodiscard constexpr Size alignedDownTo(unsigned int hAlignment,
 						 unsigned int vAlignment) const
 	{
@@ -128,6 +142,22 @@ public:
 		};
 	}
 
+	__nodiscard constexpr Size grownBy(const Size &margins) const
+	{
+		return {
+			width + margins.width,
+			height + margins.height
+		};
+	}
+
+	__nodiscard constexpr Size shrunkBy(const Size &margins) const
+	{
+		return {
+			width > margins.width ? width - margins.width : 0,
+			height > margins.height ? height - margins.height : 0
+		};
+	}
+
 	__nodiscard Size boundedToAspectRatio(const Size &ratio) const;
 	__nodiscard Size expandedToAspectRatio(const Size &ratio) const;