implement getting image size without reading the whole image

openVulkanoCpp/Image/ImageLoader.cpp

@@ -60,4 +60,10 @@ namespace OpenVulkano::Image
 		stbi_image_free(pixelData);
 		return std::make_unique<Image>(std::move(result));
 	}
+
+	bool IImageLoader::GetDimensionsInternal(const std::string& filename, int& width, int& height)
+	{
+		int channels;
+		return stbi_info(filename.c_str(), &width, &height, &channels);
+	}
 }

openVulkanoCpp/Image/ImageLoader.hpp

@@ -21,5 +21,8 @@ namespace OpenVulkano::Image
 		static std::unique_ptr<Image> loadData(const uint8_t* data, int size, int desiredChannels = 0);
 		virtual std::unique_ptr<Image> loadFromFile(const std::string& filePath) = 0;
 		virtual std::unique_ptr<Image> loadFromMemory(const std::vector<uint8_t>& buffer) = 0;
+		virtual bool GetImageDimensions(const std::string& filename, int& width, int& height) = 0;
+	protected:
+		static bool GetDimensionsInternal(const std::string& filename, int& width, int& height);
 	};
 }

openVulkanoCpp/Image/ImageLoaderJpeg.cpp

@@ -31,6 +31,32 @@ namespace OpenVulkano::Image
 		return loadJpeg(buffer.data(), buffer.size());
 	}
 
+	bool ImageLoaderJpeg::GetImageDimensions(const std::string& filename, int& width, int& height)
+	{
+#if __has_include("turbojpeg.h")
+		auto image = Utils::ReadFile(filename);
+		tjhandle jpegDecompressor = tjInitDecompress();
+		if (!jpegDecompressor)
+		{
+			Logger::FILESYS->error("Failed to read jpeg header. Error: {}", tjGetErrorStr());
+			return false;
+		}
+		int size = 0, jpegSubsamp = 0;
+		int status = tjDecompressHeader2(jpegDecompressor, reinterpret_cast<unsigned char*>(image.Data()), image.Size(),
+		                                 &width, &height, &jpegSubsamp);
+		if (status != 0)
+		{
+			Logger::FILESYS->error("Failed to read jpeg header. Error: {}", tjGetErrorStr());
+			tjDestroy(jpegDecompressor);
+			return false;
+		}
+		tjDestroy(jpegDecompressor);
+		return true;
+#else
+		return IImageLoader::GetDimensionsInternal(filename, width, height);
+#endif
+	}
+
 	std::unique_ptr<Image> ImageLoaderJpeg::loadJpeg(const uint8_t* data, size_t size)
 	{
 #if __has_include("turbojpeg.h")

openVulkanoCpp/Image/ImageLoaderJpeg.hpp

@@ -15,7 +15,7 @@ namespace OpenVulkano::Image
 	public:
 		std::unique_ptr<Image> loadFromFile(const std::string& filePath) override;
 		std::unique_ptr<Image> loadFromMemory(const std::vector<uint8_t>& buffer) override;
-
+		bool GetImageDimensions(const std::string& filename, int& width, int& height) override;
 	private:
 		std::unique_ptr<Image> loadJpeg(const uint8_t* data, size_t size);
 	};

openVulkanoCpp/Image/ImageLoaderPng.cpp

@@ -22,4 +22,9 @@ namespace OpenVulkano::Image
 	{
 		return loadData(buffer.data(), static_cast<int>(buffer.size()));
 	}
+
+	bool ImageLoaderPng::GetImageDimensions(const std::string& filename, int& width, int& height)
+	{
+		return GetDimensionsInternal(filename, width, height);
+	}
 }

openVulkanoCpp/Image/ImageLoaderPng.hpp

@@ -15,5 +15,6 @@ namespace OpenVulkano::Image
 	public:
 		std::unique_ptr<Image> loadFromFile(const std::string& filePath) override;
 		std::unique_ptr<Image> loadFromMemory(const std::vector<uint8_t>& buffer) override;
+		bool GetImageDimensions(const std::string& filename, int& width, int& height) override;
 	};
 }