Fix up thumbnailer sample programs

include/sai.hpp

@@ -352,7 +352,7 @@ class Document : public VirtualFileSystem
 	// Returns (0,0) if an error has occured
 	std::tuple<std::uint32_t, std::uint32_t> GetCanvasSize();
 
-	// Returns (RGBA Pixel Data, Width, Height).
+	// Returns (BGRA Pixel Data, Width, Height).
 	// Returns (null,0,0) if an error has occured.
 	std::tuple<std::unique_ptr<std::byte[]>, std::uint32_t, std::uint32_t> GetThumbnail();
 

samples/Thumbnail-Sai1.cpp

@@ -11,6 +11,7 @@ Sample code for extracting the thumbnail image from a user-created sai file
 #include <iostream>
 #include <sai.hpp>
 #include <utility>
+#include <algorithm>
 
 #include "stb_image_write.h"
 
@@ -19,6 +20,18 @@ const char* const Help
 	  "\tThumbnail (filename) (output)\n"
 	  "\tWunkolo - Wunkolo@gmail.com";
 
+void ConvertBGRA8ToRGBA8(std::span<std::byte> Pixels)
+{
+	std::size_t i = 0;
+	std::size_t Count = Pixels.size();
+
+	while(i < Count)
+	{
+		std::swap<std::byte>(Pixels[i], Pixels[i + 2]);
+		i += 4;
+	}
+}
+
 int main(int argc, char* argv[])
 {
 	if( argc < 3 )
@@ -39,6 +52,7 @@ int main(int argc, char* argv[])
 	Width = Height                      = 0;
 	std::unique_ptr<std::byte[]> Pixels = {};
 	std::tie(Pixels, Width, Height)     = FileIn.GetThumbnail();
+	ConvertBGRA8ToRGBA8({ Pixels.get(), Width * Height * 4 });
 
 	stbi_write_png(argv[2], Width, Height, 4, Pixels.get(), 0);
 

samples/Thumbnail-Sai2.cpp

@@ -31,7 +31,9 @@ using ThumbnailT
 	= std::tuple<std::unique_ptr<std::byte[]>, std::uint32_t, std::uint32_t>;
 
 bool IterateCanvasItem(
-	const std::filesystem::path& FilePath, const sai2::CanvasHeader& Header,
+	const std::filesystem::path& FilePath,
+	const std::filesystem::path& DestPath,
+	const sai2::CanvasHeader& Header,
 	const sai2::CanvasEntry& TableEntry, std::span<const std::byte> Bytes
 )
 {
@@ -47,10 +49,6 @@ bool IterateCanvasItem(
 		if( const auto JpegStream = sai2::ExtractJssfToJpeg(Bytes);
 			!std::get<0>(JpegStream).empty() )
 		{
-			std::filesystem::path DestPath(FilePath);
-			DestPath.replace_filename(FilePath.stem().string() + "-thumbnail");
-			DestPath.replace_extension("png");
-
 			// Decode jpeg stream
 			const auto JpegData = std::get<0>(JpegStream);
 
@@ -85,10 +83,6 @@ bool IterateCanvasItem(
 		if( auto Extracted = sai2::ExtractDpcmToBGRA(Header, Bytes);
 			!std::get<0>(Extracted).empty() )
 		{
-			std::filesystem::path DestPath(FilePath);
-			DestPath.replace_filename(FilePath.stem().string() + "-thumbnail");
-			DestPath.replace_extension("png");
-
 			std::vector<std::byte>& ThumbnailData = std::get<0>(Extracted);
 
 			const std::span<std::uint32_t> ThumbnailImage(
@@ -133,42 +127,45 @@ int main(int argc, char* argv[])
 		Args.emplace_back(argv[i]);
 	}
 
-	for( const std::string_view& Arg : Args )
+	if(Args.size() < 2)
 	{
-		std::puts(Arg.data());
-		const std::filesystem::path FilePath(Arg);
-		if( !(std::filesystem::exists(FilePath)
-			  && std::filesystem::is_regular_file(FilePath)) )
-		{
-			// Not a file
-			std::printf("Invalid path %s\n", Arg.data());
-			continue;
-		}
-		const std::uintmax_t FileSize = std::filesystem::file_size(FilePath);
+		std::puts("Input and output paths required.");
+		return EXIT_FAILURE;
+	}
 
-		std::ifstream          File(FilePath);
-		std::vector<std::byte> FileData(FileSize);
+	const std::filesystem::path FilePath(Args[0]);
+	const std::filesystem::path DestPath(Args[1]);
+	if( !(std::filesystem::exists(FilePath)
+			&& std::filesystem::is_regular_file(FilePath)) )
+	{
+		// Not a file
+		std::printf("Invalid path %s\n", FilePath.string().c_str());
+		return EXIT_FAILURE;
+	}
+	const std::uintmax_t FileSize = std::filesystem::file_size(FilePath);
 
-		if( File.is_open() )
-		{
-			File.read(reinterpret_cast<char*>(FileData.data()), FileSize);
-			File.close();
-
-			const auto CanvasDataProc = [&FilePath](
-											const sai2::CanvasHeader& Header,
-											const sai2::CanvasEntry& TableEntry,
-											std::span<const std::byte> Bytes
-										) {
-				return IterateCanvasItem(FilePath, Header, TableEntry, Bytes);
-			};
-
-			sai2::IterateCanvasData(FileData, CanvasDataProc);
-		}
-		else
-		{
-			std::printf("Error reading file contents %s\n", Arg.data());
-			continue;
-		}
+	std::ifstream          File(FilePath);
+	std::vector<std::byte> FileData(FileSize);
+
+	if( File.is_open() )
+	{
+		File.read(reinterpret_cast<char*>(FileData.data()), FileSize);
+		File.close();
+
+		const auto CanvasDataProc = [&FilePath, &DestPath](
+										const sai2::CanvasHeader& Header,
+										const sai2::CanvasEntry& TableEntry,
+										std::span<const std::byte> Bytes
+									) {
+			return IterateCanvasItem(FilePath, DestPath, Header, TableEntry, Bytes);
+		};
+
+		sai2::IterateCanvasData(FileData, CanvasDataProc);
+	}
+	else
+	{
+		std::printf("Error reading file contents %s\n", FilePath.string().c_str());
+		return EXIT_FAILURE;
 	}
 
 	return EXIT_SUCCESS;

source/document.cpp

@@ -3,9 +3,6 @@
 
 #include <sai.hpp>
 
-#ifdef __x86_64__
-#include <immintrin.h>
-#endif
 namespace sai
 {
 
@@ -52,31 +49,6 @@ std::tuple<std::unique_ptr<std::byte[]>, std::uint32_t, std::uint32_t> Document:
 
 		Thumbnail->Read({Pixels.get(), PixelCount * sizeof(std::uint32_t)});
 
-#if 0
-		//// BGRA to RGBA
-		std::size_t i = 0;
-
-		//// Simd speedup, four pixels at a time
-		while( i < ((PixelCount * sizeof(std::uint32_t)) & ~0xF) )
-		{
-			const __m128i Swizzle
-				= _mm_set_epi8(15, 12, 13, 14, 11, 8, 9, 10, 7, 4, 5, 6, 3, 0, 1, 2);
-
-			__m128i QuadPixel = _mm_loadu_si128(reinterpret_cast<__m128i*>(&Pixels[i]));
-
-			QuadPixel = _mm_shuffle_epi8(QuadPixel, Swizzle);
-
-			_mm_store_si128(reinterpret_cast<__m128i*>(&Pixels[i]), QuadPixel);
-
-			i += (sizeof(std::uint32_t) * 4);
-		}
-
-		for( ; i < PixelCount * sizeof(std::uint32_t); i += sizeof(std::uint32_t) )
-		{
-			std::swap<std::byte>(Pixels[i], Pixels[i + 2]);
-		}
-#endif
-
 		return std::make_tuple(std::move(Pixels), Header.Width, Header.Height);
 	}
 	return std::make_tuple(nullptr, 0, 0);