Enabled arcs render after adapting OpenCNCPilot code.

Started porting iosender to C++

gcode_parser.h

@@ -0,0 +1,68 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <memory>
+#include "glm/vec3.hpp"
+#include "string_utils.h"
+#include <istream>
+#include <regex>
+#include <iostream>
+#include <array>
+#include <cstring>
+#include <cmath>
+#include "gcode_commands.h"
+
+namespace grbl {
+
+    // direct translation from OpenCNCPilot
+
+    enum class parse_distance_mode {
+        absolute,
+        incremental
+    };
+
+    enum class parse_unit {
+        metric,
+        imperial
+    };
+
+    struct parser_state {
+        glm::vec<3, double> position = {0, 0, 0};
+
+        // true if the position for this coordinate was previously specified in absolute terms, to prevent the start point of (0, 0, 0) to influence the output file
+        bool position_valid[3] = {false, false, false};
+
+        arc_plane plane = arc_plane::xy;
+        double feed = 0;
+        parse_distance_mode distance_mode = parse_distance_mode::absolute;
+        parse_distance_mode arc_distance_mode = parse_distance_mode::incremental;
+        parse_unit unit = parse_unit::metric;
+        int last_motion_mode = -1;
+    };
+
+
+    struct parse_exception : public std::exception {
+        parse_exception(const std::string &reason, size_t lineNumber);
+        const char *what() const noexcept override;
+
+        std::string reason;
+        size_t line_number;
+    };
+
+    struct grbl_parser {
+        parser_state state;
+        std::vector<std::shared_ptr<command>> commands;
+        std::vector<std::string> warnings;
+
+        grbl_parser();
+        void reset();
+        void parse(std::istream &in);
+        void parse(std::string line, int line_number);
+
+    private:
+        static std::string cleanup_line(std::string line, int line_number);
+        static bool is_motion_command(double param);
+    };
+
+}