# https://github.com/jheinen/GR.jl


supportedArgs(::GRBackend) = [
    :annotations,
    :background_color, :foreground_color, :color_palette,
    :background_color_legend, :background_color_inside, :background_color_outside,
    :foreground_color_legend, :foreground_color_grid, :foreground_color_axis,
    :foreground_color_text, :foreground_color_border,
    :group,
    :label,
    :seriestype,
    :seriescolor, :seriesalpha,
    :linecolor, :linestyle, :linewidth, :linealpha,
    :markershape, :markercolor, :markersize, :markeralpha,
    :markerstrokewidth, :markerstrokecolor, :markerstrokealpha,
    :fillrange, :fillcolor, :fillalpha,
    :bins,
    :n, :nc, :nr, :layout,
    :smooth,
    :title, :windowtitle, :show, :size,
    :x, :xguide, :xlims, :xticks, :xscale, :xflip,
    :y, :yguide, :ylims, :yticks, :yscale, :yflip,
    # :axis, :yrightlabel,
    :z, :zguide, :zlims, :zticks, :zscale, :zflip,
    :z,
    :tickfont, :guidefont, :legendfont,
    :grid, :legend, :colorbar,
    :marker_z, :levels,
    :xerror, :yerror,
    :ribbon, :quiver,
    :orientation,
    :overwrite_figure,
    :polar,
    :aspect_ratio
  ]
supportedAxes(::GRBackend) = _allAxes
supportedTypes(::GRBackend) = [
    :none, :line, :path, :steppre, :steppost,
    :scatter, :hist2d, :hexbin, :hist, :density,
    :bar, :sticks,
    :hline, :vline, :heatmap, :pie, :image, #:ohlc,
    :contour, :path3d, :scatter3d, :surface, :wireframe
  ]
supportedStyles(::GRBackend) = [:auto, :solid, :dash, :dot, :dashdot, :dashdotdot]
supportedMarkers(::GRBackend) = vcat(_allMarkers, Shape)
supportedScales(::GRBackend) = [:identity, :log10]
subplotSupported(::GRBackend) = true
nativeImagesSupported(::GRBackend) = true


# --------------------------------------------------------------------------------------


function _initialize_backend(::GRBackend; kw...)
  @eval begin
    import GR
    export GR
  end
end

const gr_linetype = KW(
  :auto => 1, :solid => 1, :dash => 2, :dot => 3, :dashdot => 4,
  :dashdotdot => -1 )

const gr_markertype = KW(
  :auto => 1, :none => -1, :ellipse => -1, :rect => -7, :diamond => -13,
  :utriangle => -3, :dtriangle => -5, :pentagon => -21, :hexagon => -22,
  :heptagon => -23, :octagon => -24, :cross => 2, :xcross => 5,
  :star4 => -25, :star5 => -26, :star6 => -27, :star7 => -28, :star8 => -29,
  :vline => -30, :hline => -31 )

const gr_halign = KW(:left => 1, :hcenter => 2, :right => 3)
const gr_valign = KW(:top => 1, :vcenter => 3, :bottom => 5)

const gr_font_family = Dict(
  "times" => 1, "helvetica" => 5, "courier" => 9, "bookman" => 14,
  "newcenturyschlbk" => 18, "avantgarde" => 22, "palatino" => 26)

function gr_getcolorind(v)
  c = getColor(v)
  return convert(Int, GR.inqcolorfromrgb(c.r, c.g, c.b))
end

function gr_getaxisind(p)
  # axis = get(p, :axis, :none)
  axis = :left
  if axis in [:none, :left]
    return 1
  else
    return 2
  end
end

function gr_setmarkershape(p)
  if p[:markershape] != :none
    shape = p[:markershape]
    if isa(shape, Shape)
      p[:vertices] = vertices(shape)
    else
      GR.setmarkertype(gr_markertype[shape])
      p[:vertices] = :none
    end
  end
end

function gr_polymarker(p, x, y)
  if p[:vertices] != :none
    vertices= p[:vertices]
    dx = Float64[el[1] for el in vertices] * 0.01
    dy = Float64[el[2] for el in vertices] * 0.01
    GR.selntran(0)
    GR.setfillcolorind(gr_getcolorind(p[:markercolor]))
    GR.setfillintstyle(GR.INTSTYLE_SOLID)
    for i = 1:length(x)
      xn, yn = GR.wctondc(x[i], y[i])
      GR.fillarea(xn + dx, yn + dy)
    end
    GR.selntran(1)
  else
    GR.polymarker(x, y)
  end
end

function gr_polyline(x, y)
  if NaN in x || NaN in y
    i = 1
    j = 1
    n = length(x)
    while i < n
      while j < n && x[j] != Nan && y[j] != NaN
        j += 1
      end
      if i < j
        GR.polyline(x[i:j], y[i:j])
      end
      i = j + 1
    end
  else
    GR.polyline(x, y)
  end
end

function gr_polaraxes(rmin, rmax)
  GR.savestate()
  GR.setlinetype(GR.LINETYPE_SOLID)
  GR.setlinecolorind(88)
  tick = 0.5 * GR.tick(rmin, rmax)
  n = round(Int, (rmax - rmin) / tick + 0.5)
  for i in 0:n
    r = float(i) / n
    if i % 2 == 0
      GR.setlinecolorind(88)
      if i > 0
        GR.drawarc(-r, r, -r, r, 0, 359)
      end
      GR.settextalign(GR.TEXT_HALIGN_LEFT, GR.TEXT_VALIGN_HALF)
      x, y = GR.wctondc(0.05, r)
      GR.text(x, y, string(signif(rmin + i * tick, 12)))
    else
      GR.setlinecolorind(90)
      GR.drawarc(-r, r, -r, r, 0, 359)
    end
  end
  for alpha in 0:45:315
    a = alpha + 90
    sinf = sin(a * pi / 180)
    cosf = cos(a * pi / 180)
    GR.polyline([sinf, 0], [cosf, 0])
    GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_HALF)
    x, y = GR.wctondc(1.1 * sinf, 1.1 * cosf)
    GR.textext(x, y, string(alpha, "^o"))
  end
  GR.restorestate()
end

function gr_getzlims(d, zmin, zmax, adjust)
  if d[:zlims] != :auto
    zlims = d[:zlims]
    if zlims[1] != NaN
      zmin = zlims[1]
    end
    if zlims[2] != NaN
      zmax = zlims[2]
    end
    adjust = false
  end
  if adjust
    zmin, zmax = GR.adjustrange(zmin, zmax)
  end
  zmin, zmax
end

function gr_display(plt::Plot{GRBackend}, clear=true, update=true,
                    subplot=[0, 1, 0, 1])
  d = plt.plotargs

  clear && GR.clearws()

  mwidth, mheight, width, height = GR.inqdspsize()
  w, h = d[:size]
  viewport = zeros(4)
  vp = float(subplot)
  if w > h
    ratio = float(h) / w
    msize = mwidth * w / width
    GR.setwsviewport(0, msize, 0, msize * ratio)
    GR.setwswindow(0, 1, 0, ratio)
    vp[3] *= ratio
    vp[4] *= ratio
  else
    ratio = float(w) / h
    msize = mheight * h / height
    GR.setwsviewport(0, msize * ratio, 0, msize)
    GR.setwswindow(0, ratio, 0, 1)
    vp[1] *= ratio
    vp[2] *= ratio
  end
  viewport[1] = vp[1] + 0.125 * (vp[2] - vp[1])
  viewport[2] = vp[1] + 0.95  * (vp[2] - vp[1])
  viewport[3] = vp[3] + 0.125 * (vp[4] - vp[3])
  if w > h
    viewport[3] += (1 - (subplot[4] - subplot[3])^2) * 0.02
  end
  viewport[4] = vp[3] + 0.95  * (vp[4] - vp[3])

  bg = gr_getcolorind(d[:background_color]) # TODO: background for all subplots?
  fg = gr_getcolorind(d[:foreground_color])

  GR.savestate()
  GR.selntran(0)
  GR.setfillintstyle(GR.INTSTYLE_SOLID)
  GR.setfillcolorind(gr_getcolorind(d[:background_color_outside]))
  GR.fillrect(vp[1], vp[2], vp[3], vp[4])
  c = getColor(d[:background_color_inside])
  dark_bg = 0.21 * c.r + 0.72 * c.g + 0.07 * c.b < 0.9
  GR.setfillcolorind(gr_getcolorind(d[:background_color_inside]))
  GR.fillrect(viewport[1], viewport[2], viewport[3], viewport[4])
  GR.selntran(1)
  GR.restorestate()

  extrema = zeros(2, 4)
  num_axes = 1
  cmap = false
  axes_2d = true
  grid_flag = get(d, :grid, true)
  outside_ticks = false

  for axis = 1:2
    xmin = ymin = typemax(Float64)
    xmax = ymax = typemin(Float64)
    for p in plt.seriesargs
      st = p[:seriestype]
      if get(d, :polar, false)
        st = :polar
      end
      if axis == gr_getaxisind(p)
        if axis == 2
          num_axes = 2
        end
        if st == :bar
          x, y = 1:length(p[:y]), p[:y]
        # elseif st == :ohlc
        #   x, y = 1:size(p[:y], 1), p[:y]
        elseif st in [:hist, :density]
          x, y = Base.hist(p[:y], p[:bins])
        elseif st in [:hist2d, :hexbin]
          E = zeros(length(p[:x]),2)
          E[:,1] = p[:x]
          E[:,2] = p[:y]
          if isa(p[:bins], Tuple)
            xbins, ybins = p[:bins]
          else
            xbins = ybins = p[:bins]
          end
          cmap = true
          x, y, H = Base.hist2d(E, xbins, ybins)
        elseif st in [:pie, :polar]
          axes_2d = false
          xmin, xmax, ymin, ymax = 0, 1, 0, 1
          x, y = p[:x], p[:y]
        else
          if st in [:contour, :surface, :heatmap]
            cmap = true
          end
          if st in [:surface, :wireframe, :path3d, :scatter3d]
            axes_2d = false
          end
          if st == :heatmap
            outside_ticks = true
          end
          x, y = p[:x], p[:y]
        end
        if !(st in [:pie, :polar])
          xmin = min(minimum(x), xmin)
          xmax = max(maximum(x), xmax)
        #   if st == :ohlc
        #     for val in y
        #       ymin = min(val.open, val.high, val.low, val.close, ymin)
        #       ymax = max(val.open, val.high, val.low, val.close, ymax)
        #     end
        #   else
            ymin = min(minimum(y), ymin)
            ymax = max(maximum(y), ymax)
        #   end
          if p[:xerror] != nothing || p[:yerror] != nothing
            dx = xmax - xmin
            xmin -= 0.02 * dx
            xmax += 0.02 * dx
            dy = ymax - ymin
            ymin -= 0.02 * dy
            ymax += 0.02 * dy
          end
        end
      end
    end
    if d[:xlims] != :auto
      xmin, xmax = d[:xlims]
    end
    if d[:ylims] != :auto
      ymin, ymax = d[:ylims]
    end
    if xmax <= xmin
      xmax = xmin + 1
    end
    if ymax <= ymin
      ymax = ymin + 1
    end
    extrema[axis,:] = [xmin, xmax, ymin, ymax]
  end

  if num_axes == 2 || !axes_2d
    viewport[2] -= 0.0525
  end
  if cmap
    viewport[2] -= 0.1
  end
  GR.setviewport(viewport[1], viewport[2], viewport[3], viewport[4])

  scale = 0
  d[:xscale] == :log10 && (scale |= GR.OPTION_X_LOG)
  d[:yscale] == :log10 && (scale |= GR.OPTION_Y_LOG)
  get(d, :xflip, false) && (scale |= GR.OPTION_FLIP_X)
  get(d, :yflip, false) && (scale |= GR.OPTION_FLIP_Y)

  for axis = 1:num_axes
    xmin, xmax, ymin, ymax = extrema[axis,:]
    if scale & GR.OPTION_X_LOG == 0
      xmin, xmax = GR.adjustlimits(xmin, xmax)
      majorx = 5
      xtick = GR.tick(xmin, xmax) / majorx
    else
      xtick = majorx = 1
    end
    if scale & GR.OPTION_Y_LOG == 0
      ymin, ymax = GR.adjustlimits(ymin, ymax)
      majory = 5
      ytick = GR.tick(ymin, ymax) / majory
    else
      ytick = majory = 1
    end
    if scale & GR.OPTION_FLIP_X == 0
      xorg = (xmin, xmax)
    else
      xorg = (xmax, xmin)
    end
    if scale & GR.OPTION_FLIP_Y == 0
      yorg = (ymin, ymax)
    else
      yorg = (ymax, ymin)
    end

    extrema[axis,:] = [xmin, xmax, ymin, ymax]
    GR.setwindow(xmin, xmax, ymin, ymax)
    GR.setscale(scale)

    diag = sqrt((viewport[2] - viewport[1])^2 + (viewport[4] - viewport[3])^2)
    charheight = max(0.018 * diag, 0.01)
    GR.setcharheight(charheight)
    GR.settextcolorind(fg)

    if axes_2d
      GR.setlinewidth(1)
      GR.setlinecolorind(gr_getcolorind(d[:foreground_color_grid]))
      ticksize = 0.0075 * diag
      if outside_ticks
        ticksize = -ticksize
      end
      if grid_flag
        if dark_bg
          GR.grid(xtick * majorx, ytick * majory, 0, 0, 1, 1)
        else
          GR.grid(xtick, ytick, 0, 0, majorx, majory)
        end
      end
      GR.setlinecolorind(gr_getcolorind(d[:foreground_color_axis]))
      if num_axes == 1
        GR.axes(xtick, ytick, xorg[1], yorg[1], majorx, majory, ticksize)
        GR.axes(xtick, ytick, xorg[2], yorg[2], -majorx, -majory, -ticksize)
      elseif axis == 1
        GR.axes(xtick, ytick, xorg[1], yorg[1], majorx, majory, ticksize)
      else
        GR.axes(xtick, ytick, xorg[2], yorg[2], -majorx, majory, -ticksize)
      end
    end
  end

  if get(d, :title, "") != ""
    GR.savestate()
    GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_TOP)
    GR.settextcolorind(fg)
    GR.text(0.5 * (viewport[1] + viewport[2]), vp[4], d[:title])
    GR.restorestate()
  end
  if get(d, :xguide, "") != ""
    GR.savestate()
    GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_BOTTOM)
    GR.settextcolorind(fg)
    GR.text(0.5 * (viewport[1] + viewport[2]), vp[3], d[:xguide])
    GR.restorestate()
  end
  if get(d, :yguide, "") != ""
    GR.savestate()
    GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_TOP)
    GR.setcharup(-1, 0)
    GR.settextcolorind(fg)
    GR.text(vp[1], 0.5 * (viewport[3] + viewport[4]), d[:yguide])
    GR.restorestate()
  end
  # if get(d, :yrightlabel, "") != ""
  #   GR.savestate()
  #   GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_TOP)
  #   GR.setcharup(1, 0)
  #   GR.settextcolorind(fg)
  #   GR.text(vp[2], 0.5 * (viewport[3] + viewport[4]), d[:yrightlabel])
  #   GR.restorestate()
  # end

  GR.setcolormap(1000 + GR.COLORMAP_COOLWARM)

  legend = falses(length(plt.seriesargs))

  for (ind, p) in enumerate(plt.seriesargs)
    st = p[:seriestype]
    if st in (:hist2d, :hexbin, :contour, :surface, :wireframe, :heatmap)
      if isa(p[:fillcolor], ColorGradient)
        grad = p[:fillcolor]
      else
        grad = default_gradient()
      end
      cs = [getColorZ(grad, z) for z in linspace(0, 1, 256)]
      for (i, c) in enumerate(cs)
         GR.setcolorrep(999+i, red(c), green(c), blue(c))
      end
    end
    if get(d, :polar, false)
      st = :polar
    end
    GR.savestate()
    xmin, xmax, ymin, ymax = extrema[gr_getaxisind(p),:]
    GR.setwindow(xmin, xmax, ymin, ymax)
    if st in [:path, :line, :steppre, :steppost, :sticks, :hline, :vline, :polar] # :ohlc, :polar]
      GR.setlinetype(gr_linetype[p[:linestyle]])
      GR.setlinewidth(p[:linewidth])
      GR.setlinecolorind(gr_getcolorind(p[:linecolor]))
    end
    if st == :path
      if length(p[:x]) > 1
        if p[:fillrange] != nothing
          GR.setfillcolorind(gr_getcolorind(p[:fillcolor]))
          GR.setfillintstyle(GR.INTSTYLE_SOLID)
          GR.fillarea([p[:x][1]; p[:x]; p[:x][length(p[:x])]], [p[:fillrange]; p[:y]; p[:fillrange]])
        end
        GR.polyline(p[:x], p[:y])
      end
      legend[ind] = true
    end
    if st == :line
      if length(p[:x]) > 1
        gr_polyline(p[:x], p[:y])
      end
      legend[ind] = true
    elseif st in [:steppre, :steppost]
      n = length(p[:x])
      x = zeros(2*n + 1)
      y = zeros(2*n + 1)
      x[1], y[1] = p[:x][1], p[:y][1]
      j = 2
      for i = 2:n
        if st == :steppre
          x[j], x[j+1] = p[:x][i-1], p[:x][i]
          y[j], y[j+1] = p[:y][i],   p[:y][i]
        else
          x[j], x[j+1] = p[:x][i],   p[:x][i]
          y[j], y[j+1] = p[:y][i-1], p[:y][i]
        end
        j += 2
      end
      if n > 1
        GR.polyline(x, y)
      end
      legend[ind] = true
    elseif st == :sticks
      x, y = p[:x], p[:y]
      for i = 1:length(y)
        GR.polyline([x[i], x[i]], [ymin, y[i]])
      end
      legend[ind] = true
    elseif st == :scatter || (p[:markershape] != :none && axes_2d)
      GR.setmarkercolorind(gr_getcolorind(p[:markercolor]))
      gr_setmarkershape(p)
      if typeof(p[:markersize]) <: Number
        GR.setmarkersize(p[:markersize] / 4.0)
        if length(p[:x]) > 0
          gr_polymarker(p, p[:x], p[:y])
        end
      else
        c = p[:markercolor]
        GR.setcolormap(-GR.COLORMAP_GLOWING)
        for i = 1:length(p[:x])
          if isa(c, ColorGradient) && p[:marker_z] != nothing
            ci = round(Int, 1000 + p[:marker_z][i] * 255)
            GR.setmarkercolorind(ci)
          end
          GR.setmarkersize(p[:markersize][i] / 4.0)
          gr_polymarker(p, [p[:x][i]], [p[:y][i]])
        end
      end
      legend[ind] = true
    elseif st == :bar
      y = p[:y]
      for i = 1:length(y)
        GR.setfillcolorind(gr_getcolorind(p[:fillcolor]))
        GR.setfillintstyle(GR.INTSTYLE_SOLID)
        GR.fillrect(i-0.4, i+0.4, max(0, ymin), y[i])
        GR.setfillcolorind(fg)
        GR.setfillintstyle(GR.INTSTYLE_HOLLOW)
        GR.fillrect(i-0.4, i+0.4, max(0, ymin), y[i])
      end
    elseif st in [:hist, :density]
      h = Base.hist(p[:y], p[:bins])
      x, y = float(collect(h[1])), float(h[2])
      for i = 2:length(y)
        GR.setfillcolorind(gr_getcolorind(p[:fillcolor]))
        GR.setfillintstyle(GR.INTSTYLE_SOLID)
        GR.fillrect(x[i-1], x[i], ymin, y[i])
        GR.setfillcolorind(fg)
        GR.setfillintstyle(GR.INTSTYLE_HOLLOW)
        GR.fillrect(x[i-1], x[i], ymin, y[i])
      end
    elseif st in [:hline, :vline]
      for xy in p[:y]
        if st == :hline
          GR.polyline([xmin, xmax], [xy, xy])
        else
          GR.polyline([xy, xy], [ymin, ymax])
        end
      end
    elseif st in [:hist2d, :hexbin]
      E = zeros(length(p[:x]),2)
      E[:,1] = p[:x]
      E[:,2] = p[:y]
      if isa(p[:bins], Tuple)
        xbins, ybins = p[:bins]
      else
        xbins = ybins = p[:bins]
      end
      x, y, H = Base.hist2d(E, xbins, ybins)
      counts = round(Int32, 1000 + 255 * H / maximum(H))
      n, m = size(counts)
      GR.cellarray(xmin, xmax, ymin, ymax, n, m, counts)
      GR.setviewport(viewport[2] + 0.02, viewport[2] + 0.05,
                     viewport[3], viewport[4])
      zmin, zmax = gr_getzlims(d, 0, maximum(counts), false)
      GR.setspace(zmin, zmax, 0, 90)
      diag = sqrt((viewport[2] - viewport[1])^2 + (viewport[4] - viewport[3])^2)
      charheight = max(0.016 * diag, 0.01)
      GR.setcharheight(charheight)
      GR.colormap()
      GR.setviewport(viewport[1], viewport[2], viewport[3], viewport[4])
    elseif st == :contour
      x, y, z = p[:x], p[:y], transpose_z(p, p[:z].surf, false)
      zmin, zmax = gr_getzlims(d, minimum(z), maximum(z), false)
      GR.setspace(zmin, zmax, 0, 90)
      if typeof(p[:levels]) <: Array
        h = p[:levels]
      else
        h = linspace(zmin, zmax, p[:levels])
      end
      GR.contour(x, y, h, reshape(z, length(x) * length(y)), 1000)
      GR.setviewport(viewport[2] + 0.02, viewport[2] + 0.05,
                     viewport[3], viewport[4])
      l = round(Int32, 1000 + (h - minimum(h)) / (maximum(h) - minimum(h)) * 255)
      GR.setwindow(xmin, xmax, zmin, zmax)
      GR.cellarray(xmin, xmax, zmax, zmin, 1, length(l), l)
      ztick = 0.5 * GR.tick(zmin, zmax)
      diag = sqrt((viewport[2] - viewport[1])^2 + (viewport[4] - viewport[3])^2)
      charheight = max(0.016 * diag, 0.01)
      GR.setcharheight(charheight)
      GR.axes(0, ztick, xmax, zmin, 0, 1, 0.005)
      GR.setviewport(viewport[1], viewport[2], viewport[3], viewport[4])
    elseif st in [:surface, :wireframe]
      x, y, z = p[:x], p[:y], transpose_z(p, p[:z].surf, false)
      zmin, zmax = gr_getzlims(d, minimum(z), maximum(z), true)
      GR.setspace(zmin, zmax, 40, 70)
      xtick = GR.tick(xmin, xmax) / 2
      ytick = GR.tick(ymin, ymax) / 2
      ztick = GR.tick(zmin, zmax) / 2
      diag = sqrt((viewport[2] - viewport[1])^2 + (viewport[4] - viewport[3])^2)
      charheight = max(0.018 * diag, 0.01)
      ticksize = 0.01 * (viewport[2] - viewport[1])
      GR.setlinewidth(1)
      if grid_flag
        GR.grid3d(xtick, 0, ztick, xmin, ymin, zmin, 2, 0, 2)
        GR.grid3d(0, ytick, 0, xmax, ymin, zmin, 0, 2, 0)
      end
      z = reshape(z, length(x) * length(y))
      if st == :surface
        GR.gr3.surface(x, y, z, GR.OPTION_COLORED_MESH)
      else
        GR.setfillcolorind(0)
        GR.surface(x, y, z, GR.OPTION_FILLED_MESH)
      end
      GR.setlinewidth(1)
      GR.setcharheight(charheight)
      GR.axes3d(xtick, 0, ztick, xmin, ymin, zmin, 2, 0, 2, -ticksize)
      GR.axes3d(0, ytick, 0, xmax, ymin, zmin, 0, 2, 0, ticksize)
      if cmap
        GR.setviewport(viewport[2] + 0.07, viewport[2] + 0.1,
                       viewport[3], viewport[4])
        GR.colormap()
      end
    elseif st == :heatmap
      x, y, z = p[:x], p[:y], transpose_z(p, p[:z].surf, false)
      zmin, zmax = gr_getzlims(d, minimum(z), maximum(z), true)
      GR.setspace(zmin, zmax, 0, 90)
      z = reshape(z, length(x) * length(y))
      GR.surface(x, y, z, GR.OPTION_COLORED_MESH)
      if cmap
        GR.setviewport(viewport[2] + 0.02, viewport[2] + 0.05,
                       viewport[3], viewport[4])
        GR.colormap()
        GR.setviewport(viewport[1], viewport[2], viewport[3], viewport[4])
      end
    elseif st in [:path3d, :scatter3d]
      x, y, z = p[:x], p[:y], p[:z]
      zmin, zmax = gr_getzlims(d, minimum(z), maximum(z), true)
      GR.setspace(zmin, zmax, 40, 70)
      xtick = GR.tick(xmin, xmax) / 2
      ytick = GR.tick(ymin, ymax) / 2
      ztick = GR.tick(zmin, zmax) / 2
      diag = sqrt((viewport[2] - viewport[1])^2 + (viewport[4] - viewport[3])^2)
      charheight = max(0.018 * diag, 0.01)
      ticksize = 0.01 * (viewport[2] - viewport[1])
      GR.setlinewidth(1)
      if grid_flag && st == :path3d
        GR.grid3d(xtick, 0, ztick, xmin, ymin, zmin, 2, 0, 2)
        GR.grid3d(0, ytick, 0, xmax, ymin, zmin, 0, 2, 0)
      end
      if st == :scatter3d
        GR.setmarkercolorind(gr_getcolorind(p[:markercolor]))
        gr_setmarkershape(p)
        for i = 1:length(z)
          px, py = GR.wc3towc(x[i], y[i], z[i])
          gr_polymarker(p, [px], [py])
        end
      else
        if length(x) > 0
          GR.setlinewidth(p[:linewidth])
          GR.polyline3d(x, y, z)
        end
      end
      GR.setlinewidth(1)
      GR.setcharheight(charheight)
      GR.axes3d(xtick, 0, ztick, xmin, ymin, zmin, 2, 0, 2, -ticksize)
      GR.axes3d(0, ytick, 0, xmax, ymin, zmin, 0, 2, 0, ticksize)
    # elseif st == :ohlc
    #   y = p[:y]
    #   n = size(y, 1)
    #   ticksize = 0.5 * (xmax - xmin) / n
    #   for i in 1:n
    #     GR.polyline([i-ticksize, i], [y[i].open, y[i].open])
    #     GR.polyline([i, i], [y[i].low, y[i].high])
    #     GR.polyline([i, i+ticksize], [y[i].close, y[i].close])
    #   end
    elseif st == :pie
      GR.selntran(0)
      GR.setfillintstyle(GR.INTSTYLE_SOLID)
      xmin, xmax, ymin, ymax = viewport
      ymax -= 0.05 * (xmax - xmin)
      xcenter = 0.5 * (xmin + xmax)
      ycenter = 0.5 * (ymin + ymax)
      if xmax - xmin > ymax - ymin
        r = 0.5 * (ymax - ymin)
        xmin, xmax = xcenter - r, xcenter + r
      else
        r = 0.5 * (xmax - xmin)
        ymin, ymax = ycenter - r, ycenter + r
      end
      labels, slices = p[:x], p[:y]
      numslices = length(slices)
      total = sum(slices)
      a1 = 0
      x = zeros(3)
      y = zeros(3)
      for i in 1:numslices
        a2 = round(Int, a1 + (slices[i] / total) * 360.0)
        GR.setfillcolorind(980 + (i-1) % 20)
        GR.fillarc(xmin, xmax, ymin, ymax, a1, a2)
        alpha = 0.5 * (a1 + a2)
        cosf = r * cos(alpha * pi / 180)
        sinf = r * sin(alpha * pi / 180)
        x[1] = xcenter + cosf
        y[1] = ycenter + sinf
        x[2] = x[1] + 0.1 * cosf
        y[2] = y[1] + 0.1 * sinf
        y[3] = y[2]
        if 90 <= alpha < 270
          x[3] = x[2] - 0.05
          GR.settextalign(GR.TEXT_HALIGN_RIGHT, GR.TEXT_VALIGN_HALF)
          GR.text(x[3] - 0.01, y[3], string(labels[i]))
        else
          x[3] = x[2] + 0.05
          GR.settextalign(GR.TEXT_HALIGN_LEFT, GR.TEXT_VALIGN_HALF)
          GR.text(x[3] + 0.01, y[3], string(labels[i]))
        end
        GR.polyline(x, y)
        a1 = a2
      end
      GR.selntran(1)
    elseif st == :image
      img = p[:z].surf
      w, h = size(img)
      if eltype(img) <: Colors.AbstractGray
        grey = round(UInt8, float(img) * 255)
        rgba = map(c -> UInt32( 0xff000000 + Int(c)<<16 + Int(c)<<8 + Int(c) ), grey)
      else
        rgba = map(c -> UInt32( round(Int, alpha(c) * 255) << 24 +
                                round(Int,  blue(c) * 255) << 16 +
                                round(Int, green(c) * 255) << 8  +
                                round(Int,   red(c) * 255) ), img)
      end
      GR.drawimage(xmin, xmax, ymin, ymax, w, h, rgba)
    elseif st == :polar
      xmin, xmax, ymin, ymax = viewport
      ymax -= 0.05 * (xmax - xmin)
      xcenter = 0.5 * (xmin + xmax)
      ycenter = 0.5 * (ymin + ymax)
      r = 0.5 * min(xmax - xmin, ymax - ymin)
      GR.setviewport(xcenter -r, xcenter + r, ycenter - r, ycenter + r)
      GR.setwindow(-1, 1, -1, 1)
      rmin, rmax = GR.adjustrange(minimum(r), maximum(r))
      gr_polaraxes(rmin, rmax)
      phi, r = p[:x], p[:y]
      r = 0.5 * (r - rmin) / (rmax - rmin)
      n = length(r)
      x = zeros(n)
      y = zeros(n)
      for i in 1:n
        x[i] = r[i] * cos(phi[i])
        y[i] = r[i] * sin(phi[i])
      end
      GR.polyline(x, y)
    end
    GR.restorestate()
  end

  if d[:legend] != :none && any(legend) == true
    GR.savestate()
    GR.selntran(0)
    GR.setscale(0)
    w = 0
    i = 0
    n = 0
    for (ind, p) in enumerate(plt.seriesargs)
      if !legend[ind] || p[:label] == ""
        continue
      end
      n += 1
      if typeof(p[:label]) <: Array
        i += 1
        lab = p[:label][i]
      else
        lab = p[:label]
      end
      tbx, tby = GR.inqtext(0, 0, lab)
      w = max(w, tbx[3])
    end
    px = viewport[2] - 0.05 - w
    py = viewport[4] - 0.06
    dy = 0.03 * sqrt((viewport[2] - viewport[1])^2 + (viewport[4] - viewport[3])^2)
    GR.setfillintstyle(GR.INTSTYLE_SOLID)
    GR.setfillcolorind(gr_getcolorind(d[:background_color_legend]))
    GR.fillrect(px - 0.08, px + w + 0.02, py + dy, py - dy * n)
    GR.setlinetype(1)
    GR.setlinewidth(1)
    GR.drawrect(px - 0.08, px + w + 0.02, py + dy, py - dy * n)
    i = 0
    for (ind, p) in enumerate(plt.seriesargs)
      if !legend[ind] || p[:label] == ""
        continue
      end
      GR.setlinewidth(p[:linewidth])
      if p[:seriestype] in [:path, :line, :steppre, :steppost, :sticks]
        GR.setlinecolorind(gr_getcolorind(p[:linecolor]))
        GR.setlinetype(gr_linetype[p[:linestyle]])
        GR.polyline([px - 0.07, px - 0.01], [py, py])
      end
      if p[:seriestype] == :scatter || p[:markershape] != :none
        GR.setmarkercolorind(gr_getcolorind(p[:markercolor]))
        gr_setmarkershape(p)
        if p[:seriestype] in [:path, :line, :steppre, :steppost, :sticks]
          gr_polymarker(p, [px - 0.06, px - 0.02], [py, py])
        else
          gr_polymarker(p, [px - 0.06, px - 0.04, px - 0.02], [py, py, py])
        end
      end
      if typeof(p[:label]) <: Array
        i += 1
        lab = p[:label][i]
      else
        lab = p[:label]
      end
      GR.settextalign(GR.TEXT_HALIGN_LEFT, GR.TEXT_VALIGN_HALF)
      GR.settextcolorind(gr_getcolorind(d[:foreground_color_legend]))
      GR.text(px, py, lab)
      py -= dy
    end
    GR.selntran(1)
    GR.restorestate()
  end

  if haskey(d, :anns)
    GR.savestate()
    for ann in d[:anns]
      x, y, val = ann
      x, y = GR.wctondc(x, y)
      alpha = val.font.rotation
      family = lowercase(val.font.family)
      GR.setcharheight(0.7 * val.font.pointsize / d[:size][2])
      GR.setcharup(sin(val.font.rotation), cos(val.font.rotation))
      if haskey(gr_font_family, family)
        GR.settextfontprec(100 + gr_font_family[family], GR.TEXT_PRECISION_STRING)
      end
      GR.settextcolorind(gr_getcolorind(val.font.color))
      GR.settextalign(gr_halign[val.font.halign], gr_valign[val.font.valign])
      GR.text(x, y, val.str)
    end
    GR.restorestate()
  end

  update && GR.updatews()
end

# function gr_display(subplt::Subplot{GRBackend})
#   clear = true
#   update = false
#   l = enumerate(subplt.layout)
#   nr = nrows(subplt.layout)
#   for (i, (r, c)) in l
#     nc = ncols(subplt.layout, r)
#     if i == length(l)
#       update = true
#     end
#     subplot = [(c-1)/nc, c/nc, 1-r/nr, 1-(r-1)/nr]
#     gr_display(subplt.plts[i], clear, update, subplot)
#     clear = false
#   end
# end

# function _create_plot(pkg::GRBackend, d::KW)
#   Plot(nothing, pkg, 0, d, KW[])
# end

# function _series_added(::GRBackend, plt::Plot, d::KW)
#   push!(plt.seriesargs, d)
#   plt
# end

function _add_annotations{X,Y,V}(plt::Plot{GRBackend}, anns::AVec{@compat(Tuple{X,Y,V})})
  if haskey(plt.plotargs, :anns)
    append!(plt.plotargs[:anns], anns)
  else
    plt.plotargs[:anns] = anns
  end
end

# ----------------------------------------------------------------

# function _before_update_plot(plt::Plot{GRBackend})
# end

function _update_plot(plt::Plot{GRBackend}, d::KW)
  for k in (:title, :xguide, :yguide)
    haskey(d, k) && (plt.plotargs[k] = d[k])
  end
end

# function _update_plot_pos_size(plt::AbstractPlot{GRBackend}, d::KW)
# end

# ----------------------------------------------------------------

function getxy(plt::Plot{GRBackend}, i::Int)
  d = plt.seriesargs[i]
  d[:x], d[:y]
end

function setxy!{X,Y}(plt::Plot{GRBackend}, xy::Tuple{X,Y}, i::Integer)
  d = plt.seriesargs[i]
  d[:x], d[:y] = xy
  plt
end

# ----------------------------------------------------------------

# function _create_subplot(subplt::Subplot{GRBackend}, isbefore::Bool)
#   true
# end
#
# function _expand_limits(lims, plt::Plot{GRBackend}, isx::Bool)
#   # TODO: call expand limits for each plot data
# end
#
# function _remove_axis(plt::Plot{GRBackend}, isx::Bool)
#   # TODO: if plot is inner subplot, might need to remove ticks or axis labels
# end

# ----------------------------------------------------------------

function Base.writemime(io::IO, m::MIME"image/png", plt::AbstractPlot{GRBackend})
  GR.emergencyclosegks()
  ENV["GKS_WSTYPE"] = "png"
  gr_display(plt)
  GR.emergencyclosegks()
  write(io, readall("gks.png"))
end

function Base.writemime(io::IO, m::MIME"image/svg+xml", plt::AbstractPlot{GRBackend})
  GR.emergencyclosegks()
  ENV["GKS_WSTYPE"] = "svg"
  gr_display(plt)
  GR.emergencyclosegks()
  write(io, readall("gks.svg"))
end

function Base.writemime(io::IO, m::MIME"text/html", plt::AbstractPlot{GRBackend})
  writemime(io, MIME("image/svg+xml"), plt)
end

function Base.writemime(io::IO, m::MIME"application/pdf", plt::AbstractPlot{GRBackend})
  GR.emergencyclosegks()
  ENV["GKS_WSTYPE"] = "pdf"
  gr_display(plt)
  GR.emergencyclosegks()
  write(io, readall("gks.pdf"))
end

function Base.writemime(io::IO, m::MIME"application/postscript", plt::AbstractPlot{GRBackend})
  GR.emergencyclosegks()
  ENV["GKS_WSTYPE"] = "ps"
  gr_display(plt)
  GR.emergencyclosegks()
  write(io, readall("gks.ps"))
end

function Base.display(::PlotsDisplay, plt::Plot{GRBackend})
  gr_display(plt)
end

# function Base.display(::PlotsDisplay, plt::Subplot{GRBackend})
#   gr_display(plt)
#   true
# end