initial commit

.gitmodules

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+[submodule "file_reader"]
+	path = file_reader
+	url = https://forgejo.luna4.xyz/Luna/file_reader

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.31)
+project(lily_png)
+
+set(CMAKE_CXX_STANDARD 23)
+
+add_subdirectory(file_reader)
+
+add_library(lily_png STATIC library.cpp)
+
+target_link_libraries(lily_png file_read)

file_reader

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+Subproject commit 1b005488a2932156a5a5165820e93c04c39f6e55

library.cpp

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+#include "library.h"
+
+#include <iostream>
+
+static metadata parse_metadata(buffer &data)
+{
+	std::tuple<unsigned int, unsigned int, char, char, char, char, char> meta;
+	constexpr std::size_t size = std::tuple_size_v<decltype(meta)>;
+	parsing_buffer par_buf(data);
+	par_buf.point = par_buf.buf.data;
+	par_buf.consumed_size = 0;
+	read_comp(size, par_buf, meta);
+	std::println("Width {} height {}", std::get<0>(meta), std::get<1>(meta));
+	metadata m{0};
+	m.width = std::get<0>(meta);
+	m.height = std::get<1>(meta);
+	m.bit_depth = std::get<2>(meta);
+	m.color_type = std::get<3>(meta);
+	m.compression = std::get<4>(meta);
+	m.filter = std::get<5>(meta);
+	m.interface = std::get<6>(meta);
+	std::println("metadata{{ width: {}, height: {}, bit_depth: {}, color_type: {}, compression: {}, filter: {}, interface: {} }}", m.width, m.height, (int)m.bit_depth, (int)m.color_type, (int)m.compression, (int)m.filter, (int)m.interface);
+	return m;
+}
+
+char * read_png(const std::string &file_path)
+{
+	unsigned char magic[9] = {137, 80, 78, 71, 13, 10, 26, 10};
+	file_reader reader(file_path);
+	buffer head = {0};
+	head.size = 8;
+	auto head_tup = std::make_tuple(head);
+	auto re = reader.read_from_tuple(head_tup);
+	if (re.second == READ_INCOMPLETE || re.second == READ_FILE_ENDED)
+		throw std::runtime_error("Not enough size to read header");
+	if (memcmp(magic, std::get<0>(head_tup).data, 8) != 0)
+		throw std::runtime_error("File is not a png");
+	metadata meta{0};
+	while (true)
+	{
+		buffer chunk_type{0};
+		chunk_type.size = 4;
+		auto chunk_head = std::make_tuple((unsigned int)0, chunk_type);
+		auto ret = reader.read_from_tuple(chunk_head);
+		if (ret.second == READ_INCOMPLETE || ret.second == READ_FILE_ENDED)
+			throw std::runtime_error("Incomplete chunk");
+		std::println("Header stats size {} type {}", std::get<0>(chunk_head), std::get<1>(chunk_head).data);
+		buffer data_body{0};
+		data_body.size = std::get<0>(chunk_head);
+		auto data = std::make_tuple(data_body, chunk_type);
+		ret = reader.read_from_tuple(data);
+		if (ret.second == READ_INCOMPLETE || ret.second == READ_FILE_ENDED)
+			throw std::runtime_error("Incomplete chunk");
+		if (strcmp("IHDR", std::get<1>(chunk_head).data) == 0)
+			meta = parse_metadata(std::get<0>(data));
+		break;
+	}
+}

library.h

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+#pragma once
+
+#include "file_reader/src/file_read.h"
+#include <string>
+
+struct metadata
+{
+	unsigned int width;
+	unsigned int height;
+	char bit_depth;
+	char color_type;
+	char compression;
+	char filter;
+	char interface;
+};
+
+char *read_png(const std::string &file_path);