Tidy up and consolidate the screenshot code into a single function.

src/PngWriter.cpp

@@ -8,9 +8,15 @@
 
 #include <SDL_image.h>
 
-namespace {
-void write_png(FileSystem::FileSourceFS &fs, const std::string &path, const Uint8 *bytes, int width, int height, int stride, int bytes_per_pixel, bool strip_alpha)
+void write_screenshot(const Graphics::ScreendumpState &sd, const char *destFile)
 {
+	const Uint8 *bytes = sd.pixels.get();
+	const int width = sd.width;
+	const int height = sd.height;
+	const int stride = sd.stride;
+	const int bytes_per_pixel = sd.bpp;
+	bool strip_alpha = true;
+
 	// Set up the pixel format color masks for RGB(A) byte arrays.
 	Uint32 rmask, gmask, bmask, amask;
 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
@@ -28,12 +34,9 @@ void write_png(FileSystem::FileSourceFS &fs, const std::string &path, const Uint
 	int dest_bpp = bytes_per_pixel;
 	if (strip_alpha)
 	{
-		if (amask == 0)
-		{
+		if (amask == 0) {
 			strip_alpha = false;
-		}
-		else
-		{
+		} else {
 			amask = 0;
 			dest_bpp--;
 		}
@@ -46,29 +49,20 @@ void write_png(FileSystem::FileSourceFS &fs, const std::string &path, const Uint
 	if (!strip_alpha)
 	{
 		// optimized pass when not stripping alpha.
-		for (int y = 0; y < height; ++y)
-		{
-			Uint8 *dest = static_cast<Uint8*>(surface->pixels) + (height - (y+1)) * surface->pitch;
+		for (int y = 0; y < height; ++y) {
+			Uint8 *dest = static_cast<Uint8 *>(surface->pixels) + (height - (y + 1)) * surface->pitch;
 			const Uint8 *source = bytes + y * stride;
 			memcpy(dest, source, stride);
 		}
 	}
 	else
 	{
-		for (int y = 0; y < height; ++y)
-		{
-			Uint8 *dest = static_cast<Uint8*>(surface->pixels) + (height - (y+1)) * surface->pitch;
-			const Uint8  *source = bytes + y * stride;
-			for (int x = 0; x < width; ++x)
-			{
-				// We could assume bpp is 4/3 here and just do:
-				//*dest = *source++;
-				//*dest = *source++;
-				//*dest = *source++;
-				//++source;
+		for (int y = 0; y < height; ++y) {
+			Uint8 *dest = static_cast<Uint8 *>(surface->pixels) + (height - (y + 1)) * surface->pitch;
+			const Uint8 *source = bytes + y * stride;
+			for (int x = 0; x < width; ++x) {
 
-				for (int channel = 0; channel < dest_bpp; ++channel)
-				{
+				for (int channel = 0; channel < dest_bpp; ++channel) {
 					dest[channel] = source[channel];
 				}
 				source += bytes_per_pixel;
@@ -78,22 +72,17 @@ void write_png(FileSystem::FileSourceFS &fs, const std::string &path, const Uint
 	}
 
 	// do the actual saving
-	const std::string fname = FileSystem::JoinPathBelow(fs.GetRoot(), path);
+	const std::string dir = "screenshots";
+	FileSystem::userFiles.MakeDirectory(dir);
+
+	const std::string relative_path = FileSystem::JoinPathBelow(dir, destFile);
+
+	const std::string fname = FileSystem::JoinPathBelow(FileSystem::userFiles.GetRoot(), relative_path);
 	IMG_SavePNG(surface, fname.c_str());
 
 	//cleanup after ourselves
 	SDL_FreeSurface(surface);
 	surface = nullptr;
-}
-} //namespace
-
-void write_screenshot(const Graphics::ScreendumpState &sd, const char *destFile)
-{
-	const std::string dir = "screenshots";
-	FileSystem::userFiles.MakeDirectory(dir);
-	const std::string fname = FileSystem::JoinPathBelow(dir, destFile);
-
-	write_png(FileSystem::userFiles, fname, sd.pixels.get(), sd.width, sd.height, sd.stride, sd.bpp, true);
 
-	Output("Screenshot %s saved\n", fname.c_str());
+	Output("Screenshot %s saved\n", relative_path.c_str());
 }