[nostalgia/core] Add a function for resizing tile sheets

src/nostalgia/modules/core/include/nostalgia/core/ptidxconv.hpp

@@ -11,36 +11,42 @@
 namespace nostalgia::core {
 
 [[nodiscard]]
-constexpr std::size_t ptToIdx(int x, int y, int c) noexcept {
-	constexpr auto colLength = static_cast<std::size_t>(PixelsPerTile);
-	const auto rowLength = static_cast<std::size_t>(static_cast<std::size_t>(c / TileWidth) * colLength);
-	const auto colStart = static_cast<std::size_t>(colLength * static_cast<std::size_t>(x / TileWidth));
-	const auto rowStart = static_cast<std::size_t>(rowLength * static_cast<std::size_t>(y / TileHeight));
-	const auto colOffset = static_cast<std::size_t>(x % TileWidth);
-	const auto rowOffset = static_cast<std::size_t>(static_cast<std::size_t>(y % TileHeight) * TileHeight);
+constexpr std::size_t ptToIdx(int x, int y, int c, int scale = 1) noexcept {
+	const auto tileWidth = TileWidth * scale;
+	const auto tileHeight = TileHeight * scale;
+	const auto pixelsPerTile = tileWidth * tileHeight;
+	const auto colLength = static_cast<std::size_t>(pixelsPerTile);
+	const auto rowLength = static_cast<std::size_t>(static_cast<std::size_t>(c / tileWidth) * colLength);
+	const auto colStart = static_cast<std::size_t>(colLength * static_cast<std::size_t>(x / tileWidth));
+	const auto rowStart = static_cast<std::size_t>(rowLength * static_cast<std::size_t>(y / tileHeight));
+	const auto colOffset = static_cast<std::size_t>(x % tileWidth);
+	const auto rowOffset = static_cast<std::size_t>(static_cast<std::size_t>((y % tileHeight) * tileHeight));
 	return static_cast<std::size_t>(colStart + colOffset + rowStart + rowOffset);
 }
 
 [[nodiscard]]
-constexpr std::size_t ptToIdx(const ox::Point &pt, int c) noexcept {
-	return ptToIdx(pt.x, pt.y, c * TileWidth);
+constexpr std::size_t ptToIdx(const ox::Point &pt, int c, int scale = 1) noexcept {
+	return ptToIdx(pt.x, pt.y, c * TileWidth, scale);
 }
 
 [[nodiscard]]
-constexpr ox::Point idxToPt(int i, int c) noexcept {
+constexpr ox::Point idxToPt(int i, int c, int scale = 1) noexcept {
+	const auto tileWidth = TileWidth * scale;
+	const auto tileHeight = TileHeight * scale;
+	const auto pixelsPerTile = tileWidth * tileHeight;
 	// prevent divide by zeros
 	if (!c) {
 		++c;
 	}
-	const auto t = i / PixelsPerTile; // tile number
-	const auto iti = i % PixelsPerTile; // in tile index
+	const auto t = i / pixelsPerTile; // tile number
+	const auto iti = i % pixelsPerTile; // in tile index
 	const auto tc = t % c; // tile column
 	const auto tr = t / c; // tile row
-	const auto itx = iti % TileWidth; // in tile x
-	const auto ity = iti / TileHeight; // in tile y
+	const auto itx = iti % tileWidth; // in tile x
+	const auto ity = iti / tileHeight; // in tile y
 	return {
-		itx + tc * TileWidth,
-		ity + tr * TileHeight,
+		itx + tc * tileWidth,
+		ity + tr * tileHeight,
 	};
 }
 

src/nostalgia/modules/core/include/nostalgia/core/tilesheet.hpp

@@ -565,4 +565,9 @@ oxModelBegin(CompactTileSheet)
 	oxModelField(pixels)
 oxModelEnd()
 
+ox::Vector<uint32_t> resizeTileSheetData(
+		ox::Vector<uint32_t> const&srcPixels,
+		ox::Size const&srcSize,
+		int scale = 2) noexcept;
+
 }

src/nostalgia/modules/core/src/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_library(
 	NostalgiaCore
 		gfx.cpp
+		tilesheet.cpp
 )
 
 add_subdirectory(gba)

src/nostalgia/modules/core/src/tilesheet.cpp

@@ -0,0 +1,28 @@
+
+#include <ox/std/size.hpp>
+#include <ox/std/vector.hpp>
+
+#include <nostalgia/core/ptidxconv.hpp>
+
+namespace nostalgia::core {
+
+ox::Vector<uint32_t> resizeTileSheetData(
+		ox::Vector<uint32_t> const&srcPixels,
+		ox::Size const&srcSize,
+		int scale = 2) noexcept {
+	ox::Vector<uint32_t> dst;
+	auto dstWidth = srcSize.width * scale;
+	auto dstHeight = srcSize.height * scale;
+	const auto pixelCnt = dstWidth * dstHeight;
+	dst.resize(static_cast<std::size_t>(pixelCnt));
+	for (auto i = 0; i < pixelCnt; ++i) {
+		const auto dstPt = idxToPt(i, 1, scale);
+		const auto srcPt = dstPt / ox::Point{scale, scale};
+		const auto srcIdx = ptToIdx(srcPt, 1);
+		const auto srcPixel = srcPixels[srcIdx];
+		dst[static_cast<std::size_t>(i)] = srcPixel;
+	}
+	return dst;
+}
+
+}