// Filename: winStatsStripChart.cxx
// Created by:  drose (03Dec03)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) Carnegie Mellon University.  All rights reserved.
//
// All use of this software is subject to the terms of the revised BSD
// license.  You should have received a copy of this license along
// with this source code in a file named "LICENSE."
//
////////////////////////////////////////////////////////////////////

#include "winStatsStripChart.h"
#include "winStatsMonitor.h"
#include "pStatCollectorDef.h"
#include "numeric_types.h"

static const int default_strip_chart_width = 400;
static const int default_strip_chart_height = 100;

// Surely we aren't expected to hardcode the size of a normal
// checkbox.  But Windows seems to require this data to be passed to
// CreateWindow(), so what else can I do?
size_t WinStatsStripChart::_check_box_height = 13;
size_t WinStatsStripChart::_check_box_width = 13;

bool WinStatsStripChart::_window_class_registered = false;
const char * const WinStatsStripChart::_window_class_name = "strip";

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::Constructor
//       Access: Public
//  Description:
////////////////////////////////////////////////////////////////////
WinStatsStripChart::
WinStatsStripChart(WinStatsMonitor *monitor, int thread_index,
                   int collector_index, bool show_level) :
  PStatStripChart(monitor, 
                  show_level ? monitor->get_level_view(collector_index, thread_index) : monitor->get_view(thread_index), 
                  thread_index,
                  collector_index, 
                  default_strip_chart_width,
                  default_strip_chart_height),
  WinStatsGraph(monitor)
{
  _brush_origin = 0;

  _left_margin = 96;
  _right_margin = 32;
  _top_margin = 16;
  _bottom_margin = 8;

  if (show_level) {
    // If it's a level-type graph, show the appropriate units.
    if (_unit_name.empty()) {
      set_guide_bar_units(GBU_named);
    } else {
      set_guide_bar_units(GBU_named | GBU_show_units);
    }

  } else {
    // If it's a time-type graph, show the ms/Hz units.
    set_guide_bar_units(get_guide_bar_units() | GBU_show_units);
  }

  _smooth_check_box = 0;

  create_window();
  clear_region();
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::Destructor
//       Access: Public, Virtual
//  Description:
////////////////////////////////////////////////////////////////////
WinStatsStripChart::
~WinStatsStripChart() {
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::new_collector
//       Access: Public, Virtual
//  Description: Called whenever a new Collector definition is
//               received from the client.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
new_collector(int collector_index) {
  WinStatsGraph::new_collector(collector_index);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::new_data
//       Access: Public, Virtual
//  Description: Called as each frame's data is made available.  There
//               is no gurantee the frames will arrive in order, or
//               that all of them will arrive at all.  The monitor
//               should be prepared to accept frames received
//               out-of-order or missing.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
new_data(int thread_index, int frame_number) {
  if (is_title_unknown()) {
    string window_title = get_title_text();
    if (!is_title_unknown()) {
      SetWindowText(_window, window_title.c_str());
    }
  }

  if (!_pause) {
    update();

    string text = format_number(get_average_net_value(), get_guide_bar_units(), get_guide_bar_unit_name());
    if (_net_value_text != text) {
      _net_value_text = text;
      RECT rect;
      GetClientRect(_window, &rect);
      rect.bottom = _top_margin;
      InvalidateRect(_window, &rect, TRUE);
    }
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::force_redraw
//       Access: Public, Virtual
//  Description: Called when it is necessary to redraw the entire graph.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
force_redraw() {
  PStatStripChart::force_redraw();
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::changed_graph_size
//       Access: Public, Virtual
//  Description: Called when the user has resized the window, forcing
//               a resize of the graph.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
changed_graph_size(int graph_xsize, int graph_ysize) {
  PStatStripChart::changed_size(graph_xsize, graph_ysize);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::set_time_units
//       Access: Public, Virtual
//  Description: Called when the user selects a new time units from
//               the monitor pulldown menu, this should adjust the
//               units for the graph to the indicated mask if it is a
//               time-based graph.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
set_time_units(int unit_mask) {
  int old_unit_mask = get_guide_bar_units();
  if ((old_unit_mask & (GBU_hz | GBU_ms)) != 0) {
    unit_mask = unit_mask & (GBU_hz | GBU_ms);
    unit_mask |= (old_unit_mask & GBU_show_units);
    set_guide_bar_units(unit_mask);

    RECT rect;
    GetClientRect(_window, &rect);
    rect.left = _right_margin;
    InvalidateRect(_window, &rect, TRUE);

    GetClientRect(_window, &rect);
    rect.bottom = _top_margin;
    InvalidateRect(_window, &rect, TRUE);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::set_scroll_speed
//       Access: Public
//  Description: Called when the user selects a new scroll speed from
//               the monitor pulldown menu, this should adjust the
//               speed for the graph to the indicated value.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
set_scroll_speed(double scroll_speed) {
  // The speed factor indicates chart widths per minute.
  if (scroll_speed != 0.0f) {
    set_horizontal_scale(60.0f / scroll_speed);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::clicked_label
//       Access: Public, Virtual
//  Description: Called when the user single-clicks on a label.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
clicked_label(int collector_index) {
  if (collector_index < 0) {
    // Clicking on whitespace in the graph is the same as clicking on
    // the top label.
    collector_index = get_collector_index();
  }

  if (collector_index == get_collector_index() && collector_index != 0) {
    // Clicking on the top label means to go up to the parent level.
    const PStatClientData *client_data = 
      WinStatsGraph::_monitor->get_client_data();
    if (client_data->has_collector(collector_index)) {
      const PStatCollectorDef &def =
        client_data->get_collector_def(collector_index);
      if (def._parent_index == 0 && get_view().get_show_level()) {
        // Unless the parent is "Frame", and we're not a time collector.
      } else {
        set_collector_index(def._parent_index);
      }
    }

  } else {
    // Clicking on any other label means to focus on that.
    set_collector_index(collector_index);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::set_vertical_scale
//       Access: Public
//  Description: Changes the value the height of the vertical axis
//               represents.  This may force a redraw.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
set_vertical_scale(double value_height) {
  PStatStripChart::set_vertical_scale(value_height);

  RECT rect;
  GetClientRect(_window, &rect);
  rect.left = _right_margin;
  InvalidateRect(_window, &rect, TRUE);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::update_labels
//       Access: Protected, Virtual
//  Description: Resets the list of labels.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
update_labels() {
  PStatStripChart::update_labels();

  _label_stack.clear_labels();
  for (int i = 0; i < get_num_labels(); i++) {
    _label_stack.add_label(WinStatsGraph::_monitor, this, _thread_index,
                           get_label_collector(i), false);
  }
  _labels_changed = false;
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::clear_region
//       Access: Protected, Virtual
//  Description: Erases the chart area.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
clear_region() {
  RECT rect = { 0, 0, get_xsize(), get_ysize() };
  FillRect(_bitmap_dc, &rect, (HBRUSH)GetStockObject(WHITE_BRUSH));
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::copy_region
//       Access: Protected, Virtual
//  Description: Should be overridden by the user class to copy a
//               region of the chart from one part of the chart to
//               another.  This is used to implement scrolling.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
copy_region(int start_x, int end_x, int dest_x) {
  BitBlt(_bitmap_dc, dest_x, 0, 
         end_x - start_x, get_ysize(),
         _bitmap_dc, start_x, 0,
         SRCCOPY);

  // Also shift the brush origin over, so we still get proper
  // dithering.
  _brush_origin += (dest_x - start_x);
  SetBrushOrgEx(_bitmap_dc, _brush_origin, 0, NULL);

  RECT rect = { 
    dest_x, 0, dest_x + end_x - start_x, get_ysize() 
  };
  InvalidateRect(_graph_window, &rect, FALSE);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::draw_slice
//       Access: Protected, Virtual
//  Description: Draws a single vertical slice of the strip chart, at
//               the given pixel position, and corresponding to the
//               indicated level data.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
draw_slice(int x, int w, const PStatStripChart::FrameData &fdata) {
  // Start by clearing the band first.
  RECT rect = { x, 0, x + w, get_ysize() };
  FillRect(_bitmap_dc, &rect, (HBRUSH)GetStockObject(WHITE_BRUSH));

  double overall_time = 0.0;
  int y = get_ysize();

  FrameData::const_iterator fi;
  for (fi = fdata.begin(); fi != fdata.end(); ++fi) {
    const ColorData &cd = (*fi);
    overall_time += cd._net_value;
    HBRUSH brush = get_collector_brush(cd._collector_index);

    if (overall_time > get_vertical_scale()) {
      // Off the top.  Go ahead and clamp it by hand, in case it's so
      // far off the top we'd overflow the 16-bit pixel value.
      rect.top = 0;
      rect.bottom = y;
      FillRect(_bitmap_dc, &rect, brush);
      // And we can consider ourselves done now.
      return;
    }

    int top_y = height_to_pixel(overall_time);
    rect.top = top_y;
    rect.bottom = y;
    FillRect(_bitmap_dc, &rect, brush);
    y = top_y;
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::draw_empty
//       Access: Protected, Virtual
//  Description: Draws a single vertical slice of background color.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
draw_empty(int x, int w) {
  RECT rect = { x, 0, x + w, get_ysize() };
  FillRect(_bitmap_dc, &rect, (HBRUSH)GetStockObject(WHITE_BRUSH));
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::draw_cursor
//       Access: Protected, Virtual
//  Description: Draws a single vertical slice of foreground color.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
draw_cursor(int x) {
  RECT rect = { x, 0, x + 1, get_ysize() };
  FillRect(_bitmap_dc, &rect, (HBRUSH)GetStockObject(BLACK_BRUSH));
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::end_draw
//       Access: Protected, Virtual
//  Description: Should be overridden by the user class.  This hook
//               will be called after drawing a series of color bars
//               in the strip chart; it gives the pixel range that
//               was just redrawn.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
end_draw(int from_x, int to_x) {
  // Draw in the guide bars.
  int num_guide_bars = get_num_guide_bars();
  for (int i = 0; i < num_guide_bars; i++) {
    draw_guide_bar(_bitmap_dc, from_x, to_x, get_guide_bar(i));
  }

  RECT rect = { 
    from_x, 0, to_x + 1, get_ysize() 
  };
  InvalidateRect(_graph_window, &rect, FALSE);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::window_proc
//       Access: Protected
//  Description: 
////////////////////////////////////////////////////////////////////
LONG WinStatsStripChart::
window_proc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) {
  switch (msg) {
  case WM_LBUTTONDOWN:
    if (_potential_drag_mode == DM_new_guide_bar) {
      set_drag_mode(DM_new_guide_bar);
      SetCapture(_graph_window);
      return 0;
    }
    break;

  case WM_COMMAND:
    switch (LOWORD(wparam)) {
    case BN_CLICKED:
      if ((HWND)lparam == _smooth_check_box) {
        int result = SendMessage(_smooth_check_box, BM_GETCHECK, 0, 0);
        set_average_mode(result == BST_CHECKED);
        return 0;
      }
      break;
    }
    break;

  default:
    break;
  }

  return WinStatsGraph::window_proc(hwnd, msg, wparam, lparam);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::graph_window_proc
//       Access: Protected
//  Description: 
////////////////////////////////////////////////////////////////////
LONG WinStatsStripChart::
graph_window_proc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) {
  switch (msg) {
  case WM_LBUTTONDOWN:
    if (_potential_drag_mode == DM_none) {
      set_drag_mode(DM_scale);
      PN_int16 y = HIWORD(lparam);
      _drag_scale_start = pixel_to_height(y);
      SetCapture(_graph_window);
      return 0;

    } else if (_potential_drag_mode == DM_guide_bar && _drag_guide_bar >= 0) {
      set_drag_mode(DM_guide_bar);
      PN_int16 y = HIWORD(lparam);
      _drag_start_y = y;
      SetCapture(_graph_window);
      return 0;
    }
    break;

  case WM_MOUSEMOVE: 
    if (_drag_mode == DM_none && _potential_drag_mode == DM_none) {
      // When the mouse is over a color bar, highlight it.
      PN_int16 x = LOWORD(lparam);
      PN_int16 y = HIWORD(lparam);
      _label_stack.highlight_label(get_collector_under_pixel(x, y));

      // Now we want to get a WM_MOUSELEAVE when the mouse leaves the
      // graph window.
      TRACKMOUSEEVENT tme = {
        sizeof(TRACKMOUSEEVENT),
        TME_LEAVE,
        _graph_window,
        0
      };
      TrackMouseEvent(&tme);

    } else {
      // If the mouse is in some drag mode, stop highlighting.
      _label_stack.highlight_label(-1);
    }

    if (_drag_mode == DM_scale) {
      PN_int16 y = HIWORD(lparam);
      double ratio = 1.0f - ((double)y / (double)get_ysize());
      if (ratio > 0.0f) {
        set_vertical_scale(_drag_scale_start / ratio);
      }
      return 0;

    } else if (_drag_mode == DM_new_guide_bar) {
      // We haven't created the new guide bar yet; we won't until the
      // mouse comes within the graph's region.
      PN_int16 y = HIWORD(lparam);
      if (y >= 0 && y < get_ysize()) {
        set_drag_mode(DM_guide_bar);
        _drag_guide_bar = add_user_guide_bar(pixel_to_height(y));
        return 0;
      }

    } else if (_drag_mode == DM_guide_bar) {
      PN_int16 y = HIWORD(lparam);
      move_user_guide_bar(_drag_guide_bar, pixel_to_height(y));
      return 0;
    }
    break;

  case WM_MOUSELEAVE:
    // When the mouse leaves the graph, stop highlighting.
    _label_stack.highlight_label(-1);
    break;

  case WM_LBUTTONUP:
    if (_drag_mode == DM_scale) {
      set_drag_mode(DM_none);
      ReleaseCapture();
      return 0;

    } else if (_drag_mode == DM_guide_bar) {
      PN_int16 y = HIWORD(lparam);
      if (y < 0 || y >= get_ysize()) {
        remove_user_guide_bar(_drag_guide_bar);
      } else {
        move_user_guide_bar(_drag_guide_bar, pixel_to_height(y));
      }
      set_drag_mode(DM_none);
      ReleaseCapture();
      return 0;
    }
    break;

  case WM_LBUTTONDBLCLK:
    {
      // Double-clicking on a color bar in the graph is the same as
      // double-clicking on the corresponding label.
      PN_int16 x = LOWORD(lparam);
      PN_int16 y = HIWORD(lparam);
      clicked_label(get_collector_under_pixel(x, y));
      return 0;
    }
    break;

  default:
    break;
  }

  return WinStatsGraph::graph_window_proc(hwnd, msg, wparam, lparam);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::additional_window_paint
//       Access: Protected, Virtual
//  Description: This is called during the servicing of WM_PAINT; it
//               gives a derived class opportunity to do some further
//               painting into the window (the outer window, not the
//               graph window).
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
additional_window_paint(HDC hdc) {
  // Draw in the labels for the guide bars.
  HFONT hfnt = (HFONT)GetStockObject(ANSI_VAR_FONT); 
  SelectObject(hdc, hfnt);
  SetTextAlign(hdc, TA_LEFT | TA_TOP);
  SetBkMode(hdc, TRANSPARENT);

  RECT rect;
  GetClientRect(_window, &rect);
  int x = rect.right - _right_margin + 2;
  int last_y = -100;

  int i;
  int num_guide_bars = get_num_guide_bars();
  for (i = 0; i < num_guide_bars; i++) {
    last_y = draw_guide_label(hdc, x, get_guide_bar(i), last_y);
  }

  GuideBar top_value = make_guide_bar(get_vertical_scale());
  draw_guide_label(hdc, x, top_value, last_y);

  last_y = -100;
  int num_user_guide_bars = get_num_user_guide_bars();
  for (i = 0; i < num_user_guide_bars; i++) {
    last_y = draw_guide_label(hdc, x, get_user_guide_bar(i), last_y);
  }

  // Now draw the "net value" label at the top.
  SetTextAlign(hdc, TA_RIGHT | TA_BOTTOM);
  SetTextColor(hdc, RGB(0, 0, 0));
  TextOut(hdc, rect.right - _right_margin, _top_margin,
          _net_value_text.data(), _net_value_text.length()); 

  // Also draw the "Smooth" label on the check box.  This isn't part
  // of the check box itself, because doing that doesn't use the right
  // font!  Surely this isn't the correct Windows(tm) way to do this
  // sort of thing, but I don't know any better for now.
  SetTextAlign(hdc, TA_LEFT | TA_BOTTOM);
  TextOut(hdc, _left_margin + _check_box_width + 2, _top_margin, "Smooth", 6);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::additional_graph_window_paint
//       Access: Protected, Virtual
//  Description: This is called during the servicing of WM_PAINT; it
//               gives a derived class opportunity to do some further
//               painting into the window (the outer window, not the
//               graph window).
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
additional_graph_window_paint(HDC hdc) {
  int num_user_guide_bars = get_num_user_guide_bars();
  for (int i = 0; i < num_user_guide_bars; i++) {
    draw_guide_bar(hdc, 0, get_xsize(), get_user_guide_bar(i));
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::consider_drag_start
//       Access: Protected, Virtual
//  Description: Based on the mouse position within the window's
//               client area, look for draggable things the mouse
//               might be hovering over and return the apprioprate
//               DragMode enum or DM_none if nothing is indicated.
////////////////////////////////////////////////////////////////////
WinStatsGraph::DragMode WinStatsStripChart::
consider_drag_start(int mouse_x, int mouse_y, int width, int height) {
  if (mouse_x >= _graph_left && mouse_x < _graph_left + get_xsize()) {
    if (mouse_y >= _graph_top && mouse_y < _graph_top + get_ysize()) {
      // See if the mouse is over a user-defined guide bar.
      int y = mouse_y - _graph_top;
      double from_height = pixel_to_height(y + 2);
      double to_height = pixel_to_height(y - 2);
      _drag_guide_bar = find_user_guide_bar(from_height, to_height);
      if (_drag_guide_bar >= 0) {
        return DM_guide_bar;
      }

    } else {
      // The mouse is above or below the graph; maybe create a new
      // guide bar.
      return DM_new_guide_bar;
    }
  }

  return WinStatsGraph::consider_drag_start(mouse_x, mouse_y, width, height);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::set_drag_mode
//       Access: Protected, Virtual
//  Description: This should be called whenever the drag mode needs to
//               change state.  It provides hooks for a derived class
//               to do something special.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
set_drag_mode(WinStatsGraph::DragMode drag_mode) {
  WinStatsGraph::set_drag_mode(drag_mode);

  switch (_drag_mode) {
  case DM_scale:
  case DM_left_margin:
  case DM_right_margin:
  case DM_sizing:
    // Disable smoothing for these expensive operations.
    set_average_mode(false);
    break;

  default:
    // Restore smoothing according to the current setting of the check
    // box.
    int result = SendMessage(_smooth_check_box, BM_GETCHECK, 0, 0);
    set_average_mode(result == BST_CHECKED);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::move_graph_window
//       Access: Protected, Virtual
//  Description: Repositions the graph child window within the parent
//               window according to the _margin variables.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
move_graph_window(int graph_left, int graph_top, int graph_xsize, int graph_ysize) {
  WinStatsGraph::move_graph_window(graph_left, graph_top, graph_xsize, graph_ysize);
  if (_smooth_check_box != 0) {
    SetWindowPos(_smooth_check_box, 0, 
                 _left_margin, _top_margin - _check_box_height - 1,
                 0, 0,
                 SWP_NOZORDER | SWP_NOSIZE | SWP_SHOWWINDOW);
    InvalidateRect(_smooth_check_box, NULL, TRUE);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::draw_guide_bar
//       Access: Private
//  Description: Draws the line for the indicated guide bar on the
//               graph.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
draw_guide_bar(HDC hdc, int from_x, int to_x, 
               const PStatGraph::GuideBar &bar) {
  int y = height_to_pixel(bar._height);

  if (y > 0) {
    // Only draw it if it's not too close to the top.
    switch (bar._style) {
    case GBS_target:
      SelectObject(hdc, _light_pen);
      break;

    case GBS_user:
      SelectObject(hdc, _user_guide_bar_pen);
      break;
      
    case GBS_normal:
      SelectObject(hdc, _dark_pen);
      break;
    }
    MoveToEx(hdc, from_x, y, NULL);
    LineTo(hdc, to_x + 1, y);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::draw_guide_label
//       Access: Private
//  Description: Draws the text for the indicated guide bar label to
//               the right of the graph, unless it would overlap with
//               the indicated last label, whose top pixel value is
//               given.  Returns the top pixel value of the new label.
////////////////////////////////////////////////////////////////////
int WinStatsStripChart::
draw_guide_label(HDC hdc, int x, const PStatGraph::GuideBar &bar, int last_y) {
  switch (bar._style) {
  case GBS_target:
    SetTextColor(hdc, _light_color);
    break;
    
  case GBS_user:
    SetTextColor(hdc, _user_guide_bar_color);
    break;
    
  case GBS_normal:
    SetTextColor(hdc, _dark_color);
    break;
  }

  int y = height_to_pixel(bar._height);
  const string &label = bar._label;
  SIZE size;
  GetTextExtentPoint32(hdc, label.data(), label.length(), &size);

  if (bar._style != GBS_user) {
    double from_height = pixel_to_height(y + size.cy);
    double to_height = pixel_to_height(y - size.cy);
    if (find_user_guide_bar(from_height, to_height) >= 0) {
      // Omit the label: there's a user-defined guide bar in the same space.
      return last_y;
    }
  }

  int this_y = _graph_top + y - size.cy / 2;
  if (y >= 0 && y < get_ysize() &&
      (last_y < this_y || last_y > this_y + size.cy)) {
    TextOut(hdc, x, this_y,
            label.data(), label.length()); 
    last_y = this_y;
  }

  return last_y;
}


////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::create_window
//       Access: Private
//  Description: Creates the window for this strip chart.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
create_window() {
  if (_window) {
    return;
  }

  HINSTANCE application = GetModuleHandle(NULL);
  register_window_class(application);

  string window_title = get_title_text();

  RECT win_rect = { 
    0, 0,
    _left_margin + get_xsize() + _right_margin, 
    _top_margin + get_ysize() + _bottom_margin
  };  
  
  // compute window size based on desired client area size
  AdjustWindowRect(&win_rect, graph_window_style, FALSE);

  _window = 
    CreateWindow(_window_class_name, window_title.c_str(), graph_window_style,
                 CW_USEDEFAULT, CW_USEDEFAULT,
                 win_rect.right - win_rect.left,
                 win_rect.bottom - win_rect.top,
                 WinStatsGraph::_monitor->get_window(), NULL, application, 0);
  if (!_window) {
    nout << "Could not create StripChart window!\n";
    exit(1);
  }

  SetWindowLongPtr(_window, 0, (LONG_PTR)this);
  setup_label_stack();

  _smooth_check_box = 
    CreateWindow("BUTTON", "",
                 WS_CHILD | BS_AUTOCHECKBOX,
                 0, 0, _check_box_width, _check_box_height,
                 _window, NULL, application, 0);

  // Ensure that the window is on top of the stack.
  SetWindowPos(_window, HWND_TOP, 0, 0, 0, 0, 
               SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::register_window_class
//       Access: Private, Static
//  Description: Registers the window class for the stripChart window, if
//               it has not already been registered.
////////////////////////////////////////////////////////////////////
void WinStatsStripChart::
register_window_class(HINSTANCE application) {
  if (_window_class_registered) {
    return;
  }

  WNDCLASS wc;

  ZeroMemory(&wc, sizeof(WNDCLASS));
  wc.style = 0;
  wc.lpfnWndProc = (WNDPROC)static_window_proc;
  wc.hInstance = application;
  wc.hCursor = LoadCursor(NULL, IDC_ARROW);
  wc.hbrBackground = (HBRUSH)COLOR_BACKGROUND;
  wc.lpszMenuName = NULL;
  wc.lpszClassName = _window_class_name;

  // Reserve space to associate the this pointer with the window.
  wc.cbWndExtra = sizeof(WinStatsStripChart *);
  
  if (!RegisterClass(&wc)) {
    nout << "Could not register StripChart window class!\n";
    exit(1);
  }

  _window_class_registered = true;
}

////////////////////////////////////////////////////////////////////
//     Function: WinStatsStripChart::static_window_proc
//       Access: Private, Static
//  Description: 
////////////////////////////////////////////////////////////////////
LONG WINAPI WinStatsStripChart::
static_window_proc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) {
  WinStatsStripChart *self = (WinStatsStripChart *)GetWindowLongPtr(hwnd, 0);
  if (self != (WinStatsStripChart *)NULL && self->_window == hwnd) {
    return self->window_proc(hwnd, msg, wparam, lparam);
  } else {
    return DefWindowProc(hwnd, msg, wparam, lparam);
  }
}
