## Copyright (C) 2007-2012 David Bateman
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or (at
## your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {@var{hg} =} __scatter__ (@dots{})
## Undocumented internal function.
## @end deftypefn

function hg = __scatter__ (varargin)

  hax = varargin{1};  # We don't do anything with this.  Could remove it.
  nd  = varargin{2};
  fcn = varargin{3};
  x   = varargin{4}(:);
  y   = varargin{5}(:);

  if (nd == 2)
    idx = isnan (x) | isnan (y);
    x(idx) = [];
    y(idx) = [];
    z = zeros (length (x), 0);
    istart = 6;
  else
    z = varargin{6}(:);
    idx = isnan (x) | isnan (y) | isnan (z);
    x(idx) = [];
    y(idx) = [];
    z(idx) = [];
    istart = 7;
  endif

  firstnonnumeric = find (! cellfun ("isnumeric", varargin(istart:nargin)), 1);
  if (isempty (firstnonnumeric))
    firstnonnumeric = Inf;
  else
    firstnonnumeric += istart - 1;
  endif

  if (istart <= nargin)
    s = varargin{istart};
    if (isempty (s) || ischar (s))
      s = 6;
    endif
    if (! ischar (varargin{istart}))
      istart++;
    endif
  else
    s = 6;
  endif

  if (istart <= nargin && firstnonnumeric > istart)
    c = varargin{istart};
    if (isvector (c) && columns (c) != 3)
      c = c(:);
    endif
  ## Compare only first 4 letters of "fill" as that is what Matlab uses.
  elseif (firstnonnumeric == istart && ischar (varargin{istart})
          && ! strncmpi (varargin{istart}, "filled", 4))
    c = varargin{istart};
    firstnonnumeric++;
  else
    c = [];
  endif

  newargs = {};
  filled = false;
  have_marker = false;
  marker = "o";
  iarg = firstnonnumeric;
  while (iarg <= nargin)
    arg = varargin{iarg++};
    if (ischar (arg) && strncmpi (arg, "filled", 4))
      filled = true;
    elseif ((ischar (arg) || iscell (arg)) && ! have_marker)
      [linespec, valid] = __pltopt__ (fcn, arg, false);
      if (valid)
        have_marker = true;
        marker = linespec.marker;
        if (strcmp (marker, "none"))
          marker = "o";
        elseif (isempty (marker))
          have_marker = false;
          [~, marker] = __next_line_style__ ();
        endif
      else
        error ("%s: invalid linespec", fcn);
      endif
    else
      newargs{end+1} = arg;
      if (iarg <= nargin)
        newargs{end+1} = varargin{iarg++};
      endif
    endif
  endwhile

  if (isempty (c))
    c = __next_line_color__ ();
  endif

  hg = hggroup ();
  newargs = __add_datasource__ (fcn, hg, {"x", "y", "z", "c", "size"},
                                newargs{:});

  addproperty ("xdata", hg, "data", x);
  addproperty ("ydata", hg, "data", y);
  addproperty ("zdata", hg, "data", z);
  if (ischar (c))
    ## For single explicit color, cdata is unused
    addproperty ("cdata", hg, "data", []);
  else
    addproperty ("cdata", hg, "data", c);
  endif
  addproperty ("sizedata", hg, "data", s);
  addlistener (hg, "xdata", @update_data);
  addlistener (hg, "ydata", @update_data);
  addlistener (hg, "zdata", @update_data);
  addlistener (hg, "cdata", @update_data);
  addlistener (hg, "sizedata", @update_data);

  one_explicit_color = ischar (c) || isequal (size (c), [1, 3]);

  if (numel (x) <= 100)

    ## For small number of points, we'll construct an object for each point.

    if (numel (s) == 1)
      s = repmat (s, numel (x), 1);
    endif

    if (one_explicit_color)
      for i = 1 : numel (x)
        if (filled)
          __go_patch__ (hg, "xdata", x(i), "ydata", y(i), "zdata", z(i,:),
                        "faces", 1, "vertices", [x(i), y(i), z(i,:)],
                        "facecolor", "none", "edgecolor", "none",
                        "marker", marker,  "markersize", s(i),
                        "markeredgecolor", c, "markerfacecolor", c,
                        "linestyle", "none");
        else
          __go_patch__ (hg, "xdata", x(i), "ydata", y(i), "zdata", z(i,:),
                        "faces", 1, "vertices", [x(i), y(i), z(i,:)],
                        "facecolor", "none", "edgecolor", "none",
                        "marker", marker,  "markersize", s(i),
                        "markeredgecolor", c, "markerfacecolor", "none",
                        "linestyle", "none");
        endif
      endfor
    else
      if (rows (c) == 1)
        c = repmat (c, rows (x), 1);
      endif
      for i = 1 : numel (x)
        if (filled)
          __go_patch__ (hg, "xdata", x(i), "ydata", y(i), "zdata", z(i,:),
                        "faces", 1, "vertices", [x(i), y(i), z(i,:)],
                        "facecolor", "none", "edgecolor", "none",
                        "marker", marker, "markersize", s(i),
                        "markeredgecolor", "none",
                        "markerfacecolor", "flat",
                        "cdata", c(i,:), "facevertexcdata", c(i,:),
                        "linestyle", "none");
        else
          __go_patch__ (hg, "xdata", x(i), "ydata", y(i), "zdata", z(i,:),
                        "faces", 1, "vertices", [x(i), y(i), z(i,:)],
                        "facecolor", "none", "edgecolor", "none",
                        "marker", marker, "markersize", s(i),
                        "markeredgecolor", "flat",
                        "markerfacecolor", "none",
                        "cdata", c(i,:), "facevertexcdata", c(i,:),
                        "linestyle", "none");
        endif
      endfor
    endif

  else

    ## For larger numbers of points, we split the points by common color.

    vert = [x, y, z];
    if (one_explicit_color)
      render_size_color (hg, vert, s, c, marker, filled, true);
    else
      if (rows (c) == 1)
        c = repmat (c, rows (x), 1);
      endif
      ## We want to group points by color.  So first get all the unique colors
      [cc, ~, c_to_cc] = unique (c, "rows");

      for i = 1 : rows (cc)
        ## Now for each possible unique color, get the logical index of
        ## points that correspond to that color
        idx = (i == c_to_cc);
        if (isscalar (s))
          render_size_color (hg, vert(idx, :), s, c(idx,:),
                                 marker, filled, true);
        else
          render_size_color (hg, vert(idx, :), s(idx), c(idx,:),
                                 marker, filled, true);
        endif
      endfor

    endif
  endif

  if (! ischar (c) && rows (c) > 1)
    ax = get (hg, "parent");
    clim = get (ax, "clim");
    if (min (c(:)) < clim(1))
      clim(1) = min (c(:));
      set (ax, "clim", clim);
    endif
    if (max (c(:)) > clim(2))
      set (ax, "clim", [clim(1), max(c(:))]);
    endif
  endif

  addproperty ("linewidth", hg, "patchlinewidth", 0.5);
  addproperty ("marker", hg, "patchmarker", marker);
  if (filled)
    addproperty ("markeredgecolor", hg, "patchmarkeredgecolor", "none");
    if (one_explicit_color)
      addproperty ("markerfacecolor", hg, "patchmarkerfacecolor", c);
    else
      addproperty ("markerfacecolor", hg, "patchmarkerfacecolor", "flat");
    endif
  else
    addproperty ("markerfacecolor", hg, "patchmarkerfacecolor", "none");
    if (one_explicit_color)
      addproperty ("markeredgecolor", hg, "patchmarkeredgecolor", c);
    else
      addproperty ("markeredgecolor", hg, "patchmarkeredgecolor", "flat");
    endif
  endif
  addlistener (hg, "linewidth", @update_props);
  addlistener (hg, "marker", @update_props);
  addlistener (hg, "markerfacecolor", @update_props);
  addlistener (hg, "markeredgecolor", @update_props);

  if (! isempty (newargs))
    set (hg, newargs{:});
  endif

endfunction

function render_size_color (hg, vert, s, c, marker, filled, isflat)
  if (isscalar (s))
    x = vert(:,1);
    y = vert(:,2);
    z = vert(:,3:end);
    toolkit = get (ancestor (hg, "figure"), "__graphics_toolkit__");
    ## Does gnuplot only support triangles with different vertex colors ?
    ## TODO: Verify gnuplot can only support one color.  If RGB triplets
    ##       can be assigned to each vertex, then fix __go_draw_axes__.m
    gnuplot_hack = (numel (x) > 1 && columns (c) == 3
                    && strcmp (toolkit, "gnuplot"));
    if (ischar (c) || ! isflat || gnuplot_hack)
      if (filled)
        __go_patch__ (hg, "xdata", x, "ydata", y, "zdata", z,
                          "faces", 1:numel (x), "vertices", vert,
                          "facecolor", "none", "edgecolor", "none",
                          "marker", marker,
                          "markeredgecolor", "none",
                          "markerfacecolor", c(1,:),
                          "markersize", s, "linestyle", "none");
      else
        __go_patch__ (hg, "xdata", x, "ydata", y, "zdata", z,
                          "faces", 1:numel (x), "vertices", vert,
                          "facecolor", "none", "edgecolor", "none",
                          "marker", marker,
                          "markeredgecolor", c(1,:),
                          "markerfacecolor", "none",
                          "markersize", s, "linestyle", "none");
      endif
    else
      if (filled)
        __go_patch__ (hg, "xdata", x, "ydata", y, "zdata", z,
                          "faces", 1:numel (x), "vertices", vert,
                          "facecolor", "none", "edgecolor", "none",
                          "marker", marker, "markersize", s,
                          "markeredgecolor", "none",
                          "markerfacecolor", "flat",
                          "cdata", c, "facevertexcdata", c,
                          "linestyle", "none");
      else
        __go_patch__ (hg, "xdata", x, "ydata", y, "zdata", z,
                          "faces", 1:numel (x), "vertices", vert,
                          "facecolor", "none", "edgecolor", "none",
                          "marker", marker, "markersize", s,
                          "markeredgecolor", "flat",
                          "markerfacecolor", "none",
                          "cdata", c, "facevertexcdata", c,
                          "linestyle", "none");
      endif
    endif
  else
    ## Round size to one decimal place.
    [ss, ~, s_to_ss] = unique (ceil (s*10) / 10);
    for i = 1:rows (ss)
      idx = (i == s_to_ss);
      render_size_color (hg, vert(idx,:), ss(i), c,
                             marker, filled, isflat);
    endfor
  endif
endfunction

function update_props (h, d)
  lw = get (h, "linewidth");
  m  = get (h, "marker");
  fc = get (h, "markerfacecolor");
  ec = get (h, "markeredgecolor");
  kids = get (h, "children");

  set (kids, "linewidth", lw, "marker", m,
             "markerfacecolor", fc, "markeredgecolor", ec);
endfunction

function update_data (h, d)
  x = get (h, "xdata");
  y = get (h, "ydata");
  z = get (h, "zdata");
  c = get (h, "cdata");
  if (rows (c) == 1)
    c = repmat (c, numel (x), 1);
  endif
  s = get (h, "sizedata");
  if (numel (s) == 1)
    s = repmat (s, numel (x), 1);
  endif
  hlist = get (h, "children");

  if (isempty (z))
    for i = 1 : length (hlist)
      set (hlist(i), "vertices", [x(i), y(i)],
                     "cdata", reshape (c(i,:),[1, size(c)(2:end)]),
                     "facevertexcdata", c(i,:),
                     "markersize", s(i));
    endfor
  else
    for i = 1 : length (hlist)
      set (hlist(i), "vertices", [x(i), y(i), z(i)],
                     "cdata", reshape (cd(i,:),[1, size(cd)(2:end)]),
                     "facevertexcdata", cd(i,:),
                     "markersize", s(i));
    endfor
  endif

endfunction