From 0d889306e5788c408891457416bf2f725d7fc5d2 Mon Sep 17 00:00:00 2001
From: David Vereb <dvereb@dvereb.com>
Date: Mon, 3 Apr 2023 21:22:44 -0400
Subject: [PATCH] Added ability to flip piece data.

---
 Pieces.cpp | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 Pieces.h   |  6 ++++++
 main.cpp   | 26 ++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)

diff --git a/Pieces.cpp b/Pieces.cpp
index f596cef..1fe4318 100644
--- a/Pieces.cpp
+++ b/Pieces.cpp
@@ -406,6 +406,54 @@ PieceData RotatePieceData(const PieceData &data, Rotation rotation)
 	return rtn;
 }
 
+void FlipPieceData(PieceData &data, Flip flip)
+{
+	if(!data.size())
+		return;
+	if(!data[0].size())
+		return;
+
+	switch(flip)
+	{
+	default:
+	case Flip::FLIP_NONE:
+		return;
+	case Flip::FLIP_HORIZONTAL:
+		// Go through EVERY row:
+		for(size_t row = 0; row < data.size(); ++row)
+		{
+			// And swap the front half with the back half
+			// [1][2][3][2][1]
+			//  ^  ^     ^  ^
+			//  |  +-----+  |  <-- second
+			//  |           |
+			//  +-----------+  <-- first
+			for(size_t col = 0; col < data[0].size() / 2; ++col)
+			{
+				// for each row, swap columns
+				bool temp = data[row][col];
+				data[row][col] = data[row][data[0].size() - col - 1];
+				data[row][data[0].size() - col - 1] = temp;
+			}
+		}
+		break;
+	case Flip::FLIP_VERTICAL:
+		// Go through EVERY col:
+		for(size_t col = 0; col < data[0].size(); ++col)
+		{
+			// And swap the top half with the bottom half
+			for(size_t row = 0; row < data.size() / 2; ++row)
+			{
+				// for each row, swap columns
+				bool temp = data[row][col];
+				data[row][col] = data[data.size() - row - 1][col];
+				data[data.size() - row - 1][col] = temp;
+			}
+		}
+		break;
+	};
+}
+
 unsigned PD_PieceHeight(const PieceData &data)
 {
 	return data.size();
diff --git a/Pieces.h b/Pieces.h
index 794365b..5a6e04b 100644
--- a/Pieces.h
+++ b/Pieces.h
@@ -11,6 +11,11 @@ enum Rotation {
 	ROTATION_180,
 	ROTATION_270,
 };
+enum Flip {
+	FLIP_NONE,
+	FLIP_HORIZONTAL,
+	FLIP_VERTICAL,
+};
 
 #define NUM_PIECES 8
 typedef uint8_t Piece; // only need literally 8, not 8 bits, but hey.
@@ -148,6 +153,7 @@ void DrawPiece(const Piece &piece, int y, int x,
                Rotation rotation = Rotation::ROTATION_NONE);
 
 PieceData RotatePieceData(const PieceData &data, Rotation rotation);
+void FlipPieceData(PieceData &data, Flip flip);
 unsigned PD_PieceHeight(const PieceData &data);
 unsigned PD_PieceWidth(const PieceData &data);
 void PD_DrawPiece(const PieceData &data, int y, int x, int color = 0);
diff --git a/main.cpp b/main.cpp
index 7c9aef4..07ecf40 100644
--- a/main.cpp
+++ b/main.cpp
@@ -140,5 +140,31 @@ void DemoPieces()
 
 		getch();
 	}
+
+	std::vector<Flip> flips = {
+		Flip::FLIP_NONE,
+		Flip::FLIP_HORIZONTAL,
+		Flip::FLIP_HORIZONTAL,
+		Flip::FLIP_VERTICAL,
+		Flip::FLIP_VERTICAL,
+	};
+
+	std::vector<PieceData> piece_data_to_flip;
+	for(size_t p = 0; p < pieces.size(); ++p)
+		piece_data_to_flip.push_back(pieces.at(p));
+	for(const auto &flip : flips)
+	{
+		clear();
+		int y = 2;
+		int i = 0;
+		for(auto &data : piece_data_to_flip)
+		{
+			FlipPieceData(data, flip);
+			PD_DrawPiece(data, y, 2, i++);
+			y += PD_PieceHeight(data) + 2;
+		}
+		getch();
+	}
+
 	move(8, 2);
 }