From a2f437d4ad7570f0d5c6ac1fdd0a3cef9eeedd0f Mon Sep 17 00:00:00 2001
From: Elias Batek <desisma@heidel.beer>
Date: Mon, 7 Oct 2024 03:43:44 +0200
Subject: [PATCH] Make PixmapScanner types bidirectional ranges

---
 pixmappaint.d | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/pixmappaint.d b/pixmappaint.d
index adff89c..3c9165a 100644
--- a/pixmappaint.d
+++ b/pixmappaint.d
@@ -919,6 +919,11 @@ struct PixmapScanner {
 		_width = pixmap.width;
 	}
 
+	///
+	typeof(this) save() {
+		return this;
+	}
+
 	///
 	bool empty() const {
 		return (_data.length == 0);
@@ -933,6 +938,16 @@ struct PixmapScanner {
 	void popFront() {
 		_data = _data[_width .. $];
 	}
+
+	///
+	const(Pixel)[] back() const {
+		return _data[($ - _width) .. $];
+	}
+
+	///
+	void popBack() {
+		_data = _data[0 .. ($ - _width)];
+	}
 }
 
 /++
@@ -957,6 +972,11 @@ struct PixmapScannerRW {
 		_width = pixmap.width;
 	}
 
+	///
+	typeof(this) save() {
+		return this;
+	}
+
 	///
 	bool empty() const {
 		return (_data.length == 0);
@@ -971,6 +991,16 @@ struct PixmapScannerRW {
 	void popFront() {
 		_data = _data[_width .. $];
 	}
+
+	///
+	Pixel[] back() {
+		return _data[($ - _width) .. $];
+	}
+
+	///
+	void popBack() {
+		_data = _data[0 .. ($ - _width)];
+	}
 }
 
 /++
@@ -994,6 +1024,11 @@ struct SubPixmapScanner {
 		_feed = subPixmap.source.width;
 	}
 
+	///
+	typeof(this) save() {
+		return this;
+	}
+
 	///
 	bool empty() const {
 		return (_data.length == 0);
@@ -1013,6 +1048,16 @@ struct SubPixmapScanner {
 
 		_data = _data[_feed .. $];
 	}
+
+	///
+	const(Pixel)[] back() const {
+		return _data[($ - _width) .. $];
+	}
+
+	///
+	void popBack() {
+		_data = _data[0 .. ($ - _width)];
+	}
 }
 
 /++
@@ -1039,6 +1084,11 @@ struct SubPixmapScannerRW {
 		_feed = subPixmap.source.width;
 	}
 
+	///
+	typeof(this) save() {
+		return this;
+	}
+
 	///
 	bool empty() const {
 		return (_data.length == 0);
@@ -1058,6 +1108,16 @@ struct SubPixmapScannerRW {
 
 		_data = _data[_feed .. $];
 	}
+
+	///
+	Pixel[] back() {
+		return _data[($ - _width) .. $];
+	}
+
+	///
+	void popBack() {
+		_data = _data[0 .. ($ - _width)];
+	}
 }
 
 ///