From 1f077d2b791a059ccef4069dca07ead990bd568e Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Fri, 6 Dec 2024 21:23:44 +0100
Subject: Add Image::crop().

---
 src/lib/image.cc | 22 ++++++++++++++++++++++
 src/lib/image.h  |  2 ++
 2 files changed, 24 insertions(+)

(limited to 'src/lib')

diff --git a/src/lib/image.cc b/src/lib/image.cc
index f1586be4d..80ef92d06 100644
--- a/src/lib/image.cc
+++ b/src/lib/image.cc
@@ -60,9 +60,11 @@ using std::list;
 using std::make_shared;
 using std::max;
 using std::min;
+using std::pair;
 using std::runtime_error;
 using std::shared_ptr;
 using std::string;
+using std::vector;
 using dcp::Size;
 
 
@@ -1706,3 +1708,23 @@ Image::video_range_to_full_range ()
 	}
 }
 
+
+shared_ptr<Image>
+Image::crop(Crop crop) const
+{
+	vector<uint8_t*> scale_in_data;
+	dcp::Size cropped_size;
+	std::tie(scale_in_data, cropped_size) = crop_source_pointers(crop);
+
+	auto out = make_shared<Image>(_pixel_format, cropped_size, _alignment);
+
+	for (int c = 0; c < planes(); ++c) {
+		auto const out_data = out->data()[c];
+		for (int y = 0; y < cropped_size.height; ++y) {
+			memcpy(out_data + y * out->stride()[c], scale_in_data[c] + y * stride()[c], cropped_size.width * bytes_per_pixel(c));
+		}
+	}
+
+	return out;
+}
+
diff --git a/src/lib/image.h b/src/lib/image.h
index ce4382a42..548ebf717 100644
--- a/src/lib/image.h
+++ b/src/lib/image.h
@@ -84,6 +84,8 @@ public:
 		bool fast
 		) const;
 
+	std::shared_ptr<Image> crop(Crop crop) const;
+
 	void make_black ();
 	void make_transparent ();
 	void alpha_blend (std::shared_ptr<const Image> image, Position<int> pos);
-- 
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