Subversion Repositories DIN Is Noise

/*
* trail.cc
* DIN Is Noise is copyright (c) 2006-2021 Jagannathan Sampath
* For more information, please visit https://dinisnoise.org/
*/

#include "dingl.h"
#include "trail.h"
#include "log.h"

void trail_t::alloc (int n) {
  if (n > n_tpts) {
    n_tpts = n;
    if (tpts) delete[] tpts;
    tpts = new float [2 * n_tpts];
  }
}

trail_t::trail_t (int tp) {
  num_points = 0;
  total_points = tp;
  alloc (total_points);
}

void trail_t::add (float x, float y) {
  if (x != last.x || y != last.y) {
    last.x = x; last.y = y;
    int dt = num_points - total_points;
    if (dt > -1) {
      int npops = dt + 1;
      for (int i = 0; i < npops; ++i) {
        pts.x.pop_front ();
        pts.y.pop_front ();
      }
      num_points -= npops;
    }      
    pts.x.push_back (x);
    pts.y.push_back (y);
    ++num_points;
  }
}

void trail_t::change_size (int delta) {
  total_points += delta;
  if (delta > 0) alloc (total_points);
  else
    if (total_points < 1) total_points = 1;
}

void trail_t::draw () {
  int m = 0, n = 0;
  float x, y;
  for (std::list< float >::iterator xiter = pts.x.begin (), xjter = pts.x.end (), yiter = pts.y.begin (); xiter != xjter; ++xiter, ++yiter) {
    x = *xiter;
    y = *yiter;
    tpts[m++] = x; tpts[m++]=y;
    ++n;
  }
  glVertexPointer (2, GL_FLOAT, 0, tpts);
  glDrawArrays (GL_LINE_STRIP, 0, n);
}

#ifdef __SVG__
void trail_t::write () {
  dlog << "<polyline points=\"";
  float x, y;
  for (std::list< float >::iterator xiter = pts.x.begin (), xjter = pts.x.end (), yiter = pts.y.begin (); xiter != xjter; ++xiter, ++yiter) {
    x = *xiter;
    y = *yiter;
    dlog << x << "," << y << ' ';
  }
  dlog << "\" style=\"stroke-width:1\" fill=\"none\" stroke=\"black\"/>" << endl;
}
#endif