Use the libretro VFS interface in libretro builds

CMakeLists.txt

@@ -256,6 +256,7 @@ if(LIBRETRO)
 	if(NOT MSVC)
 		add_compile_options(-fPIC)
 	endif()
+	add_compile_definitions(HAVE_LIBRETRO_VFS)
 endif()
 
 if(ANDROID)
@@ -944,6 +945,10 @@ add_library(Common STATIC
 	Common/TimeUtil.h
 )
 
+if(LIBRETRO)
+	target_include_directories(Common PRIVATE libretro/libretro-common/include)
+endif()
+
 include_directories(Common)
 setup_target_project(Common Common)
 
@@ -1685,6 +1690,10 @@ add_library(native STATIC
 	ext/jpge/jpge.h
 )
 
+if(LIBRETRO)
+	target_include_directories(native PRIVATE libretro/libretro-common/include)
+endif()
+
 if(LINUX AND NOT ANDROID)
 	set(RT_LIB rt)
 endif()
@@ -2509,6 +2518,10 @@ add_library(${CoreLibName} ${CoreLinkType}
 	${CMAKE_CURRENT_BINARY_DIR}/git-version.cpp
 )
 
+if(LIBRETRO)
+	target_include_directories(${CoreLibName} PRIVATE libretro/libretro-common/include)
+endif()
+
 if(ANDROID)
 	set(CoreExtraLibs ${CoreExtraLibs} android)
 	if(X86_64)

Common/Data/Format/IniFile.cpp

@@ -14,7 +14,6 @@
 #endif
 
 #include <iostream>
-#include <fstream>
 #include <sstream>
 #include <string>
 #include <vector>

Common/Data/Format/PNGLoad.cpp

@@ -134,35 +134,63 @@ bool PNGHeaderPeek::IsValidPNGHeader() const {
 }
 
 bool pngSave(const Path &filename, const void *buffer, int w, int h, int bytesPerPixel) {
-	png_image png{};
-	png.version = PNG_IMAGE_VERSION;
-	png.format = bytesPerPixel == 3 ? PNG_FORMAT_RGB : PNG_FORMAT_RGBA;
-	png.width = w;
-	png.height = h;
-	const int row_stride = w * bytesPerPixel;
+	png_bytepp row_ptrs = nullptr;
 
 	FILE *fp = File::OpenCFile(filename, "wb");
 	if (!fp) {
 		ERROR_LOG(Log::IO, "Unable to open png file for writing: %s", filename.c_str());
 		return false;
 	}
 
-	int result = png_image_write_to_stdio(&png, fp, 0, buffer, row_stride, nullptr);
+	png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, pngErrorHandler, pngWarningHandler);
+	if (png_ptr == nullptr) {
+		fclose(fp);
+		ERROR_LOG(Log::IO, "PNG encode failed.");
+		return false;
+	}
 
-	if (png.warning_or_error >= 2) {
-		ERROR_LOG(Log::IO, "Saving image to PNG produced errors.");
+	png_infop info_ptr = png_create_info_struct(png_ptr);
+	if (info_ptr == nullptr) {
+		png_destroy_write_struct(&png_ptr, nullptr);
+		fclose(fp);
+		ERROR_LOG(Log::IO, "PNG encode failed.");
+		return false;
 	}
 
-	png_image_free(&png);
-	fclose(fp);
+	if (setjmp(png_jmpbuf(png_ptr))) {
+		if (row_ptrs != nullptr) {
+			png_free(png_ptr, row_ptrs);
+		}
+		png_destroy_write_struct(&png_ptr, &info_ptr);
+		fclose(fp);
 
-	if (!result) {
 		// Should we even do this?
 		File::Delete(filename);
 
 		ERROR_LOG(Log::IO, "PNG encode failed.");
 		return false;
 	}
 
+	png_set_write_fn(png_ptr, fp, [](png_structp png_ptr, png_bytep data, png_size_t size) {
+		if (fwrite(data, 1, size, (FILE *)png_get_io_ptr(png_ptr)) < size) {
+			png_error(png_ptr, "Failed to write to file.");
+		}
+	}, [](png_structp png_ptr) {
+		fflush((FILE *)png_get_io_ptr(png_ptr));
+	});
+
+	png_set_IHDR(png_ptr, info_ptr, w, h, 8, bytesPerPixel == 3 ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGBA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+	row_ptrs = (png_bytepp)png_malloc(png_ptr, (png_alloc_size_t)h * (png_alloc_size_t)sizeof(png_bytep));
+	for (png_alloc_size_t i = 0; i < h; ++i) {
+		row_ptrs[i] = (png_bytep)buffer + (png_alloc_size_t)w * (png_alloc_size_t)bytesPerPixel * i;
+	}
+	png_set_rows(png_ptr, info_ptr, row_ptrs);
+
+	png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, nullptr);
+
+	png_free(png_ptr, row_ptrs);
+	png_destroy_write_struct(&png_ptr, &info_ptr);
+	fclose(fp);
 	return true;
 }