BMP palette parser + Logger macro

4 files changed, 308 insertions, 0 deletions

diff --git a/src/openvic/utility/BMP.cpp b/src/openvic/utility/BMP.cpp
new file mode 100644
index 0000000..eb3e2b1
--- /dev/null
+++ b/src/openvic/utility/BMP.cpp
@@ -0,0 +1,162 @@
+#include "BMP.hpp"
+
+#include <set>
+
+#include "Logger.hpp"
+
+using namespace OpenVic;
+
+BMP::~BMP() {
+	close();
+}
+
+return_t BMP::open(char const* filepath) {
+	reset();
+	errno = 0;
+	file = fopen(filepath, "rb");
+	if (file == nullptr || errno != 0) {
+		Logger::error("Failed to open BMP file \"", filepath, "\" (errno = ", errno, ")");
+		file = nullptr;
+		return FAILURE;
+	}
+	return SUCCESS;
+}
+
+return_t BMP::read_header() {
+	if (header_validated) {
+		Logger::error("BMP header already validated!");
+		return FAILURE;
+	}
+	if (file == nullptr) {
+		Logger::error("Cannot read BMP header before opening a file");
+		return FAILURE;
+	}
+	if (fseek(file, 0, SEEK_SET) != 0) {
+		Logger::error("Failed to move to the beginning of the BMP file!");
+		return FAILURE;
+	}
+	if (fread(&header, sizeof(header), 1, file) != 1) {
+		Logger::error("Failed to read BMP header!");
+		return FAILURE;
+	}
+	return_t ret = SUCCESS;
+
+	// Validate constants
+	static constexpr uint16_t BMP_SIGNATURE = 0x4d42;
+	if (header.signature != BMP_SIGNATURE) {
+		Logger::error("Invalid BMP signature: ", header.signature, " (must be ", BMP_SIGNATURE, ")");
+		ret = FAILURE;
+	}
+	static constexpr uint32_t DIB_HEADER_SIZE = 40;
+	if (header.dib_header_size != DIB_HEADER_SIZE) {
+		Logger::error("Invalid BMP DIB header size: ", header.dib_header_size, " (must be ", DIB_HEADER_SIZE, ")");
+		ret = FAILURE;
+	}
+	static constexpr uint16_t NUM_PLANES = 1;
+	if (header.num_planes != NUM_PLANES) {
+		Logger::error("Invalid BMP plane count: ", header.num_planes, " (must be ", NUM_PLANES, ")");
+		ret = FAILURE;
+	}
+	static constexpr uint16_t COMPRESSION = 0; // Only support uncompressed BMPs
+	if (header.compression != COMPRESSION) {
+		Logger::error("Invalid BMP compression method: ", header.compression, " (must be ", COMPRESSION, ")");
+		ret = FAILURE;
+	}
+
+	// Validate sizes and dimensions
+	// TODO - image_size_bytes can be 0 for non-compressed BMPs
+	if (header.file_size != header.offset + header.image_size_bytes) {
+		Logger::error("Invalid BMP memory sizes: file size = ", header.file_size, " != ", header.offset + header.image_size_bytes,
+			" = ", header.offset, " + ", header.image_size_bytes, " = image data offset + image data size");
+		ret = FAILURE;
+	}
+	// TODO - support negative widths (i.e. horizontal flip)
+	if (header.width_px <= 0) {
+		Logger::error("Invalid BMP width: ", header.width_px, " (must be positive)");
+		ret = FAILURE;
+	}
+	// TODO - support negative heights (i.e. vertical flip)
+	if (header.height_px <= 0) {
+		Logger::error("Invalid BMP height: ", header.height_px, " (must be positive)");
+		ret = FAILURE;
+	}
+	// TODO - validate x_resolution_ppm
+	// TODO - validate y_resolution_ppm
+
+	// Validate colours
+#define VALID_BITS_PER_PIXEL 1, 2, 4, 8, 16, 24, 32
+#define STR(x) #x
+	static const std::set<uint16_t> BITS_PER_PIXEL { VALID_BITS_PER_PIXEL };
+	if (!BITS_PER_PIXEL.contains(header.bits_per_pixel)) {
+		Logger::error("Invalid BMP bits per pixel: ", header.bits_per_pixel, " (must be one of " STR(VALID_BITS_PER_PIXEL) ")");
+		ret = FAILURE;
+	}
+#undef VALID_BITS_PER_PIXEL
+#undef STR
+	static constexpr uint16_t PALETTE_BITS_PER_PIXEL_LIMIT = 8;
+	if (header.num_colours != 0 && header.bits_per_pixel > PALETTE_BITS_PER_PIXEL_LIMIT) {
+		Logger::error("Invalid BMP palette size: ", header.num_colours, " (should be 0 as bits per pixel is ", header.bits_per_pixel, " > 8)");
+		ret = FAILURE;
+	}
+	// TODO - validate important_colours
+
+	palette_size = header.bits_per_pixel > PALETTE_BITS_PER_PIXEL_LIMIT ? 0
+		// Use header.num_colours if it's greater than 0 and at most 1 << header.bits_per_pixel
+		: 0 < header.num_colours && header.num_colours - 1 >> header.bits_per_pixel == 0 ? header.num_colours
+		: 1 << header.bits_per_pixel;
+
+	const uint32_t expected_offset = palette_size * PALETTE_COLOUR_SIZE + sizeof(header);
+	if (header.offset != expected_offset) {
+		Logger::error("Invalid BMP image data offset: ", header.offset, " (should be ", expected_offset, ")");
+		ret = FAILURE;
+	}
+
+	header_validated = ret == SUCCESS;
+	return ret;
+}
+
+return_t BMP::read_palette() {
+	if (file == nullptr) {
+		Logger::error("Cannot read BMP palette before opening a file");
+		return FAILURE;
+	}
+	if (!header_validated) {
+		Logger::error("Cannot read palette before BMP header is validated!");
+		return FAILURE;
+	}
+	if (palette_size == 0) {
+		Logger::error("Cannot read BMP palette - header indicates this file doesn't have one");
+		return FAILURE;
+	}
+	if (fseek(file, sizeof(header), SEEK_SET) != 0) {
+		Logger::error("Failed to move to the palette in the BMP file!");
+		return FAILURE;
+	}
+	palette.resize(palette_size);
+	if (fread(palette.data(), palette_size * PALETTE_COLOUR_SIZE, 1, file) != 1) {
+		Logger::error("Failed to read BMP header!");
+		palette.clear();
+		return FAILURE;
+	}
+	return SUCCESS;
+}
+
+void BMP::close() {
+	if (file != nullptr) {
+		if (fclose(file) != 0)
+			Logger::error("Failed to close BMP!");
+		file = nullptr;
+	}
+}
+
+void BMP::reset() {
+	close();
+	memset(&header, 0, sizeof(header));
+	header_validated = false;
+	palette_size = 0;
+	palette.clear();
+}
+
+std::vector<colour_t> const& BMP::get_palette() const {
+	return palette;
+}
diff --git a/src/openvic/utility/BMP.hpp b/src/openvic/utility/BMP.hpp
new file mode 100644
index 0000000..c6f5815
--- /dev/null
+++ b/src/openvic/utility/BMP.hpp
@@ -0,0 +1,48 @@
+#pragma once
+
+#include "../Types.hpp"
+
+namespace OpenVic {
+	class BMP {
+#pragma pack(push)
+#pragma pack(1)
+		struct header_t {
+			uint16_t signature;			// Signature: 0x4d42 (or 'B' 'M')
+			uint32_t file_size;			// File size in bytes
+			uint16_t reserved1;			// Not used
+			uint16_t reserved2;			// Not used
+			uint32_t offset;			// Offset to image data in bytes from beginning of file
+			uint32_t dib_header_size;	// DIB header size in bytes
+			int32_t width_px;			// Width of the image
+			int32_t height_px;			// Height of image
+			uint16_t num_planes;		// Number of colour planes
+			uint16_t bits_per_pixel;	// Bits per pixel
+			uint32_t compression;		// Compression type
+			uint32_t image_size_bytes;	// Image size in bytes
+			int32_t x_resolution_ppm;	// Pixels per meter
+			int32_t y_resolution_ppm;	// Pixels per meter
+			uint32_t num_colours;		// Number of colours
+			uint32_t important_colours; // Important colours
+		} header;
+#pragma pack(pop)
+
+		FILE* file = nullptr;
+		bool header_validated = false;
+		uint32_t palette_size = 0;
+		std::vector<colour_t> palette;
+
+	public:
+		static constexpr uint32_t PALETTE_COLOUR_SIZE = sizeof(colour_t);
+
+		BMP() = default;
+		~BMP();
+
+		return_t open(char const* filepath);
+		return_t read_header();
+		return_t read_palette();
+		void close();
+		void reset();
+
+		std::vector<colour_t> const& get_palette() const;
+	};
+}
diff --git a/src/openvic/utility/Logger.cpp b/src/openvic/utility/Logger.cpp
new file mode 100644
index 0000000..fe97473
--- /dev/null
+++ b/src/openvic/utility/Logger.cpp
@@ -0,0 +1,18 @@
+#include "Logger.hpp"
+
+#include <iostream>
+
+using namespace OpenVic;
+
+Logger::log_func_t Logger::info_func = [](std::string&& str) { std::cout << str; };
+Logger::log_func_t Logger::error_func = [](std::string&& str) { std::cerr << str; };
+
+char const* Logger::get_filename(char const* filepath) {
+	if (filepath == nullptr) return nullptr;
+	char const* last_slash = filepath;
+	while (*filepath != '\0') {
+		if (*filepath == '\\' || *filepath == '/') last_slash = filepath + 1;
+		filepath++;
+	}
+	return last_slash;
+}
diff --git a/src/openvic/utility/Logger.hpp b/src/openvic/utility/Logger.hpp
new file mode 100644
index 0000000..ac82445
--- /dev/null
+++ b/src/openvic/utility/Logger.hpp
@@ -0,0 +1,80 @@
+#pragma once
+
+#include <functional>
+#include <sstream>
+#ifdef __cpp_lib_source_location
+#include <source_location>
+#endif
+
+namespace OpenVic {
+
+#ifndef __cpp_lib_source_location
+#include <string>
+	// Implementation of std::source_location for compilers that do not support it
+	// Note: uses non-standard extensions that are supported by Clang, GCC, and MSVC
+	// https://clang.llvm.org/docs/LanguageExtensions.html#source-location-builtins
+	// https://stackoverflow.com/a/67970107
+	class source_location {
+		std::string _file;
+		int _line;
+		std::string _function;
+
+	public:
+		source_location(std::string f, int l, std::string n) : _file(f), _line(l), _function(n) {}
+		static source_location current(std::string f = __builtin_FILE(), int l = __builtin_LINE(), std::string n = __builtin_FUNCTION()) {
+			return source_location(f, l, n);
+		}
+
+		inline char const* file_name() const { return _file.c_str(); }
+		inline int line() const { return _line; }
+		inline char const* function_name() const { return _function.c_str(); }
+	};
+#endif
+
+	class Logger {
+		using log_func_t = std::function<void(std::string&&)>;
+
+#ifdef __cpp_lib_source_location
+		using source_location = std::source_location;
+#else
+		using source_location = OpenVic::source_location;
+#endif
+
+		static char const* get_filename(char const* filepath);
+
+		template<typename... Ts>
+		struct log {
+			log(log_func_t log_func, Ts&&... ts, source_location const& location) {
+				if (log_func) {
+					std::stringstream stream;
+					stream << "\n" << get_filename(location.file_name()) << "("
+						   << location.line() << ") `" << location.function_name() << "`: ";
+					((stream << std::forward<Ts>(ts)), ...);
+					stream << std::endl;
+					log_func(stream.str());
+				}
+			}
+		};
+
+#define LOG_FUNC(name)																			\
+	private:																					\
+		static log_func_t name##_func;															\
+	public:																						\
+		static void set_##name##_func(log_func_t log_func) {									\
+			name##_func = log_func;																\
+		}																						\
+		template <typename... Ts>																\
+		struct name {																			\
+			name(Ts&&... ts, source_location const& location = source_location::current()) {	\
+				log<Ts...>{ name##_func, std::forward<Ts>(ts)..., location };					\
+			}																					\
+		};																						\
+		template <typename... Ts>																\
+		name(Ts&&...) -> name<Ts...>;
+
+		LOG_FUNC(info)
+		LOG_FUNC(error)
+
+#undef LOG_FUNC
+	};
+}