GPX-Visualizer/Track.cpp

#include "Track.h"
#include "Xml.h"

#include <GL/glut.h>

#include <syslog.h>
#include <iostream>
#include <iomanip>
#include <fstream>

bool ParseFile(std::vector<Track> &out_tracks,
               const std::string &file_and_path)
{
	std::ifstream ifs(file_and_path);
	if(!ifs.is_open())
	{
		std::cerr << "Couldn't open " << file_and_path << "." << std::endl;
		return false;
	}

	// get size
	ifs.seekg(0, std::ios_base::end);
	auto end = ifs.tellg();
	std::string file_str(end, '\0');
	ifs.seekg(0, std::ios_base::beg); // back to beginning to read
	ifs.read(&file_str[0], end);

	// parse it (warning: possibly destructive / not const)
	using namespace rapidxml;
	xml_document<> doc;    // character type defaults to char
	doc.parse<0>(&file_str[0]);    // 0 means default parse flags

	xml_node<> *seg_node = recursive_find_next_node(doc.first_node(), "trkseg");
	if(!seg_node)
	{
		std::cerr << "Couldn't find any <trkseg> nodes for file \""
		          << file_and_path
		          << "\"." << std::endl;
		return false;
	}

	Track t;

	for(int seg_count = 0;
	    seg_node;
	    ++seg_count, seg_node = recursive_find_next_node(seg_node->next_sibling(), "trkseg"))
	{
		xml_node<> *node = recursive_find_next_node(seg_node, "trkpt");
		if(!node)
		{
			std::cerr << "Couldn't find a <trkpt> node for file \""
			          << file_and_path
			          << "\" <trkseg> #" << seg_count << "." << std::endl;
			return false;
		}

		// recursively search for all trkpt nodes:
		for(; node; node = recursive_find_next_node(node->next_sibling(), "trkpt"))
		{
			bool found_lat = false;
			bool found_lon = false;
			bool found_ele = false;

			Point p;
			for(xml_attribute<> *attr = node->first_attribute();
			    attr;
			    attr = attr->next_attribute())
			{
				if(std::string(attr->name()) == "lat")
				{
					try {
						p.lat = std::atof(attr->value());
						found_lat = true;
					} catch(const std::exception &e) {
						syslog(LOG_USER|LOG_DEBUG,"%s:%d:%s Error Parsing lat",
						       __FILE__,__LINE__,__PRETTY_FUNCTION__);
					}
				}
				if(std::string(attr->name()) == "lon")
				{
					try {
						p.lon = std::atof(attr->value());
						found_lon = true;
					} catch(const std::exception &e) {
						syslog(LOG_USER|LOG_DEBUG,"%s:%d:%s Error Parsing lon",
						       __FILE__,__LINE__,__PRETTY_FUNCTION__);
					}
				}
			}
			auto ele_node = node->first_node("ele");
			if(ele_node)
			{
				try {
					p.ele = std::atof(ele_node->value());
					found_ele = true;
				} catch(const std::exception &e) {
					syslog(LOG_USER|LOG_DEBUG,"%s:%d:%s Error Parsing ele",
					       __FILE__,__LINE__,__PRETTY_FUNCTION__);
				}
			}

			if(found_lat && found_lon && found_ele)
				t.points.push_back(p);
			else if(found_lat || found_lon || found_ele)
				syslog(LOG_USER|LOG_DEBUG, "%s:%d:%s Incomplete trkpt",
				       __FILE__,__LINE__,__PRETTY_FUNCTION__);
		}
	}

	// Bring track to a scale that we're comfortable rendering:
	// Grab stats:
	bool first = true;
	for(auto &p : t.points)
	{
		if(first)
		{
			first = false;
			t.min.lat = t.max.lat = p.lat;
			t.min.lon = t.max.lon = p.lon;
			t.min.ele = t.max.ele = p.ele;
		}
		else
		{
			if(p.lat < t.min.lat)
				t.min.lat = p.lat;
			else if(p.lat > t.max.lat)
				t.max.lat = p.lat;
			if(p.lon < t.min.lon)
				t.min.lon = p.lon;
			else if(p.lon > t.max.lon)
				t.max.lon = p.lon;
			if(p.ele < t.min.ele)
				t.min.ele = p.ele;
			else if(p.ele > t.max.ele)
				t.max.ele = p.ele;
		}
		// NOTE(dev): This must be done AFTER the translation so it doesn't get skewered
		// p.lat *= 500;
		// p.lon *= 500;
		// p.ele *= 0.04;
	}

	out_tracks.push_back(t);
	ifs.close();

	std::cout << std::setw(6) << t.points.size() << " tracks points "
	          << "found in \"" << file_and_path << "\"." << std::endl;

	return true;
}

void draw(const Track &track)
{
	// glLineWidth(1.0f);

	// Draw bike path
	glBegin(GL_LINE_STRIP);
	for(auto p : track.points)
	{
		// auto val = (50 + (p.ele * 10)) / 180.0;
		// val /= 2.0;

		// double  val = (p.ele - track.min.ele) / (track.max.ele - track.min.ele);
		// val /= 2.0 + 0.5;
		// val *= 255;

		// glColor3d(val, val, val);

		glColor3d(200, 200, 200);
		glVertex3f(p.lat,
		           p.ele,
		           p.lon);
	}
	glEnd();
	glutPostRedisplay();
}