[ttf] added initial partial impl of tz::io::ttf. not close to functio…

…nal, don't use

CMakeLists.txt

@@ -242,6 +242,9 @@ add_library(topaz STATIC
 	# image
 	src/tz/io/image.cpp
 	src/tz/io/image.hpp
+	# ttf
+	src/tz/io/ttf.cpp
+	src/tz/io/ttf.hpp
 
 	# tz::lua
 	src/tz/lua/api.cpp

src/tz/io/ttf.cpp

@@ -0,0 +1,66 @@
+#include "tz/io/ttf.hpp"
+#include "tz/core/debug.hpp"
+#include "tz/core/profile.hpp"
+#include <fstream>
+#include <cstdio>
+
+namespace tz::io
+{
+	ttf ttf::from_memory(std::string_view sv)
+	{
+		TZ_PROFZONE("ttf - from memory", 0xFFFF2222);
+		return {sv};
+	}
+
+	ttf ttf::from_file(const char* path)
+	{
+		TZ_PROFZONE("ttf - from file", 0xFFFF2222);
+		std::ifstream file(path, std::ios::binary);
+		tz::assert(file.good(), "Could not load ttf from file because the path was wrong, or something else went wrong.");
+		std::string buffer(std::istreambuf_iterator<char>(file), {});
+		return ttf::from_memory(buffer);
+	}
+
+	ttf::ttf(std::string_view ttf_data)
+	{
+		this->parse_header(ttf_data);
+		this->parse_table_info(ttf_data);
+	}
+
+	void ttf::parse_header(std::string_view& str)
+	{
+		const char* ptr = str.data();
+		this->header.scalar_type = *reinterpret_cast<const std::uint32_t*>(ptr);	
+		ptr += sizeof(std::uint32_t);
+		this->header.num_tables = *reinterpret_cast<const std::uint16_t*>(ptr);	
+		ptr += sizeof(std::uint16_t);
+		this->header.search_range = *reinterpret_cast<const std::uint16_t*>(ptr);
+		ptr += sizeof(std::uint16_t);
+		this->header.entry_selector = *reinterpret_cast<const std::uint16_t*>(ptr);
+		ptr += sizeof(std::uint16_t);
+		this->header.range_shift = *reinterpret_cast<const std::uint16_t*>(ptr);
+		ptr += sizeof(std::uint16_t);
+
+		auto byte_diff = std::distance(str.data(), ptr);
+		tz::assert(std::cmp_greater(str.size(), byte_diff));
+		str.remove_prefix(byte_diff);
+	}
+
+	void ttf::parse_table_info(std::string_view str)
+	{
+		const char* ptr = str.data();
+		tz::assert(this->tables.empty());
+		for(std::size_t i = 0; i < this->header.num_tables; i++)
+		{
+			ttf_table& tbl = this->tables.emplace_back();
+			std::memcpy(tbl.tag, ptr, 4);
+			ptr += 4;	
+			tbl.checksum = *reinterpret_cast<const std::uint32_t*>(ptr);
+			ptr += sizeof(std::uint32_t);
+			tbl.offset = *reinterpret_cast<const std::uint32_t*>(ptr);
+			ptr += sizeof(std::uint32_t);
+			tbl.length = *reinterpret_cast<const std::uint32_t*>(ptr);
+			ptr += sizeof(std::uint32_t);
+		}
+	}
+}

src/tz/io/ttf.hpp

@@ -0,0 +1,40 @@
+#ifndef TOPAZ_IO_TTF_HPP
+#define TOPAZ_IO_TTF_HPP
+#include <string_view>
+#include <vector>
+
+namespace tz::io
+{
+	struct ttf_header
+	{
+		std::uint32_t scalar_type = 0u;
+		std::uint16_t num_tables = 0u;
+		std::uint16_t search_range = 0u;
+		std::uint16_t entry_selector = 0u;
+		std::uint16_t range_shift = 0u;
+	};
+
+	struct ttf_table
+	{
+		char tag[4];
+		std::uint32_t checksum = 0u;
+		std::uint32_t offset = 0u;
+		std::uint32_t length = 0u;
+	};
+
+	class ttf
+	{
+	public:
+		ttf() = default;
+		static ttf from_memory(std::string_view sv);
+		static ttf from_file(const char* path);
+		ttf(std::string_view ttf_data);
+	private:
+		void parse_header(std::string_view& str);
+		void parse_table_info(std::string_view str);
+		ttf_header header = {};
+		std::vector<ttf_table> tables = {};
+	};
+}
+
+#endif //TOPAZ_IO_TTF_HPP