App declarations modified; cursor was corrupt; needed to add PostScript-related variable.

[wxWidgets.git] / src / gtk / dcclient.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        dcclient.cpp
// Purpose:
// Author:      Robert Roebling
// Created:     01/02/97
// Id:
// Copyright:   (c) 1998 Robert Roebling, Julian Smart and Markus Holzem
// Licence:   	wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#ifdef __GNUG__
#pragma implementation "dcclient.h"
#endif

#include "wx/dcclient.h"

//-----------------------------------------------------------------------------
// local data
//-----------------------------------------------------------------------------

#include "bdiag.xbm"
#include "fdiag.xbm"
#include "cdiag.xbm"
#include "horiz.xbm"
#include "verti.xbm"
#include "cross.xbm"
#define  num_hatches 6

static GdkPixmap  *hatches[num_hatches];
static GdkPixmap **hatch_bitmap = NULL;

//-----------------------------------------------------------------------------
// constants
//-----------------------------------------------------------------------------

#define RAD2DEG 57.2957795131

//-----------------------------------------------------------------------------
// wxPaintDC
//-----------------------------------------------------------------------------

IMPLEMENT_DYNAMIC_CLASS(wxPaintDC,wxDC)

wxPaintDC::wxPaintDC(void)
{
};

wxPaintDC::wxPaintDC( wxWindow *window )
{
  if (!window) return;
  GtkWidget *widget = window->m_wxwindow;
  if (!widget) return;
  m_window = widget->window;
  if (!m_window) return;
  if (window->m_wxwindow)
    m_cmap = gtk_widget_get_colormap( window->m_wxwindow );
  else
    m_cmap = gtk_widget_get_colormap( window->m_widget );
  SetUpDC();
  
  long x = 0;
  long y = 0;
  window->GetDrawingOffset( &x, &y );
  SetInternalDeviceOrigin( -x, -y );
};

wxPaintDC::~wxPaintDC(void)
{
};

void wxPaintDC::FloodFill( long WXUNUSED(x1), long WXUNUSED(y1), 
  wxColour *WXUNUSED(col), int WXUNUSED(style) )
{
};

bool wxPaintDC::GetPixel( long WXUNUSED(x1), long WXUNUSED(y1), wxColour *WXUNUSED(col) ) const
{
  return FALSE;
};

void wxPaintDC::DrawLine( long x1, long y1, long x2, long y2 )
{
  if (!Ok()) return;
  
  if (m_pen.GetStyle() != wxTRANSPARENT)
  {
    gdk_draw_line( m_window, m_penGC, 
      XLOG2DEV(x1), YLOG2DEV(y1), XLOG2DEV(x2), YLOG2DEV(y2) );
  };
};

void wxPaintDC::CrossHair( long x, long y )
{
  if (!Ok()) return;
  
  if (m_pen.GetStyle() != wxTRANSPARENT)
  {
    int w = 0;
    int h = 0;
    GetSize( &w, &h );
    long xx = XLOG2DEV(x);
    long yy = YLOG2DEV(y);
    gdk_draw_line( m_window, m_penGC,
      0, yy, XLOG2DEVREL(w), yy );
    gdk_draw_line( m_window, m_penGC,
      xx, 0, xx, YLOG2DEVREL(h) );
  };
};

void wxPaintDC::DrawArc( long x1, long y1, long x2, long y2, double xc, double yc )
{
  if (!Ok()) return;
  
  long xx1 = XLOG2DEV(x1); 
  long yy1 = YLOG2DEV(y1);
  long xx2 = XLOG2DEV(x2); 
  long yy2 = YLOG2DEV(y2);
  long xxc = XLOG2DEV((long)xc); 
  long yyc = YLOG2DEV((long)yc);
  double dx = xx1 - xxc; 
  double dy = yy1 - yyc;
  double radius = sqrt(dx*dx+dy*dy);
  long   r      = (long)radius;
  double radius1, radius2;

  if (xx1 == xx2 && yy1 == yy2) 
  {
    radius1 = 0.0;
    radius2 = 360.0;
  } 
  else 
  if (radius == 0.0) 
  {
    radius1 = radius2 = 0.0;
  } 
  else 
  {
    radius1 = (xx1 - xxc == 0) ?
	    (yy1 - yyc < 0) ? 90.0 : -90.0 :
	    -atan2(double(yy1-yyc), double(xx1-xxc)) * RAD2DEG;
    radius2 = (xx2 - xxc == 0) ?
	    (yy2 - yyc < 0) ? 90.0 : -90.0 :
	    -atan2(double(yy2-yyc), double(xx2-xxc)) * RAD2DEG;
  };
  long alpha1 = long(radius1 * 64.0);
  long alpha2 = long((radius2 - radius1) * 64.0);
  while (alpha2 <= 0) alpha2 += 360*64;
  while (alpha1 > 360*64) alpha1 -= 360*64;

  if (m_brush.GetStyle() != wxTRANSPARENT)
    gdk_draw_arc( m_window, m_brushGC, TRUE, xxc-r, yyc-r, 2*r,2*r, alpha1, alpha2 );
    
  if (m_pen.GetStyle() != wxTRANSPARENT)
    gdk_draw_arc( m_window, m_penGC, FALSE, xxc-r, yyc-r, 2*r,2*r, alpha1, alpha2 );
  
};

void wxPaintDC::DrawEllipticArc( long x, long y, long width, long height, double sa, double ea )
{
  if (!Ok()) return;
  
  if (width<0) { width=-width; x=x-width; }
  if (height<0) { height=-height; y=y-height; }

  long xx = XLOG2DEV(x);    
  long yy = YLOG2DEV(y);
  long ww = XLOG2DEVREL(width); 
  long hh = YLOG2DEVREL(height);
  
  if (m_brush.GetStyle() != wxTRANSPARENT)
    gdk_draw_arc( m_window, m_brushGC, TRUE, xx, yy, ww-1, hh-1, 0, long(sa*64) );
  
  if (m_pen.GetStyle() != wxTRANSPARENT)
    gdk_draw_arc( m_window, m_penGC, FALSE, xx, yy, ww, hh, 0, long(ea*64) );
};

void wxPaintDC::DrawPoint( long x, long y )
{
  if (!Ok()) return;
  
  if (m_pen.GetStyle() != wxTRANSPARENT)
    gdk_draw_point( m_window, m_penGC, XLOG2DEV(x), YLOG2DEV(y) );
};

void wxPaintDC::DrawLines( int n, wxPoint points[], long xoffset, long yoffset )
{
  if (!Ok()) return;
  
  if (m_pen.GetStyle() == wxTRANSPARENT) return;
  
  for (int i = 0; i < n-1; i++)
  {
    long x1 = XLOG2DEV(points[i].x + xoffset);
    long x2 = XLOG2DEV(points[i+1].x + xoffset);
    long y1 = YLOG2DEV(points[i].y + yoffset);     // oh, what a waste
    long y2 = YLOG2DEV(points[i+1].y + yoffset);
    gdk_draw_line( m_window, m_brushGC, x1, y1, x2, y2 );
  };
};

void wxPaintDC::DrawLines( wxList *points, long xoffset, long yoffset )
{
  if (!Ok()) return;
  
  if (m_pen.GetStyle() == wxTRANSPARENT) return;
  
  wxNode *node = points->First();
  while (node->Next())
  {
    wxPoint *point = (wxPoint*)node->Data();
    wxPoint *npoint = (wxPoint*)node->Next()->Data();
    long x1 = XLOG2DEV(point->x + xoffset);
    long x2 = XLOG2DEV(npoint->x + xoffset);
    long y1 = YLOG2DEV(point->y + yoffset);    // and again...
    long y2 = YLOG2DEV(npoint->y + yoffset);
    gdk_draw_line( m_window, m_brushGC, x1, y1, x2, y2 );
    node = node->Next();
  };
};

void wxPaintDC::DrawPolygon( int WXUNUSED(n), wxPoint WXUNUSED(points)[], 
  long WXUNUSED(xoffset), long WXUNUSED(yoffset), int WXUNUSED(fillStyle) )
{
  if (!Ok()) return;
};

void wxPaintDC::DrawPolygon( wxList *WXUNUSED(lines), long WXUNUSED(xoffset), 
                             long WXUNUSED(yoffset), int WXUNUSED(fillStyle) )
{
  if (!Ok()) return;
};

void wxPaintDC::DrawRectangle( long x, long y, long width, long height )
{
  if (!Ok()) return;

  long xx = XLOG2DEV(x);
  long yy = YLOG2DEV(y);
  long ww = XLOG2DEVREL(width);
  long hh = YLOG2DEVREL(height);
    
  if (m_brush.GetStyle() != wxTRANSPARENT)
    gdk_draw_rectangle( m_window, m_brushGC, TRUE, xx, yy, ww, hh );
    
  if (m_pen.GetStyle() != wxTRANSPARENT)
    gdk_draw_rectangle( m_window, m_penGC, FALSE, xx, yy, ww-1, hh-1 );
};

void wxPaintDC::DrawRoundedRectangle( long x, long y, long width, long height, double radius )
{
  if (!Ok()) return;
  
  if (width<0) { width=-width; x=x-width; }
  if (height<0) { height=-height; y=y-height; }

  if (radius < 0.0) radius = - radius * ((width < height) ? width : height);
  
  long xx = XLOG2DEV(x);    
  long yy = YLOG2DEV(y);
  long ww = XLOG2DEVREL(width); 
  long hh = YLOG2DEVREL(height);
  long rr = XLOG2DEVREL((long)radius);
  long dd = 2 * rr;

  if (m_brush.GetStyle() != wxTRANSPARENT)
  {
    gdk_draw_rectangle( m_window, m_brushGC, TRUE, xx+rr, yy, ww-dd, hh );
    gdk_draw_rectangle( m_window, m_brushGC, TRUE, xx, yy+rr, ww, hh-dd );
    gdk_draw_arc( m_window, m_brushGC, TRUE, xx, yy, dd, dd, 90*64, 90*64 );
    gdk_draw_arc( m_window, m_brushGC, TRUE, xx+ww-dd, yy, dd, dd, 0, 90*64 );
    gdk_draw_arc( m_window, m_brushGC, TRUE, xx+ww-dd, yy+hh-dd, dd, dd, 270*64, 90*64 );
    gdk_draw_arc( m_window, m_brushGC, TRUE, xx, yy+hh-dd, dd, dd, 180*64, 90*64 );
  };
  
  if (m_pen.GetStyle() != wxTRANSPARENT)
  {
    gdk_draw_line( m_window, m_penGC, xx+rr, yy, xx+ww-rr, yy );
    gdk_draw_line( m_window, m_penGC, xx+rr, yy+hh, xx+ww-rr, yy+hh );
    gdk_draw_line( m_window, m_penGC, xx, yy+rr, xx, yy+hh-rr );
    gdk_draw_line( m_window, m_penGC, xx+ww, yy+rr, xx+ww, yy+hh-rr );
    gdk_draw_arc( m_window, m_penGC, FALSE, xx, yy, dd, dd, 90*64, 90*64 );
    gdk_draw_arc( m_window, m_penGC, FALSE, xx+ww-dd, yy, dd, dd, 0, 90*64 );
    gdk_draw_arc( m_window, m_penGC, FALSE, xx+ww-dd, yy+hh-dd, dd, dd, 270*64, 90*64 );
    gdk_draw_arc( m_window, m_penGC, FALSE, xx, yy+hh-dd, dd, dd, 180*64, 90*64 );
  };
};

void wxPaintDC::DrawEllipse( long x, long y, long width, long height )
{
  if (!Ok()) return;
  
  if (width<0) { width=-width; x=x-width; }
  if (height<0) { height=-height; y=y-height; }

  long xx = XLOG2DEV(x);    
  long yy = YLOG2DEV(y);
  long ww = XLOG2DEVREL(width); 
  long hh = YLOG2DEVREL(height);
  
  if (m_brush.GetStyle() != wxTRANSPARENT)
    gdk_draw_arc( m_window, m_brushGC, TRUE, xx, yy, ww, hh, 0, 360*64 );
  
  if (m_pen.GetStyle() != wxTRANSPARENT)
    gdk_draw_arc( m_window, m_penGC, FALSE, xx, yy, ww, hh, 0, 360*64 );
};

bool wxPaintDC::CanDrawBitmap(void) const
{
  return TRUE;
};

void wxPaintDC::DrawIcon( const wxIcon &icon, long x, long y, bool useMask )
{
  if (!Ok()) return;
  
  if (!icon.Ok()) return;
  
  int xx = XLOG2DEV(x);
  int yy = YLOG2DEV(y);
  
  GdkBitmap *mask = NULL;
  if (icon.GetMask()) mask = icon.GetMask()->GetBitmap();
    
  if (useMask && mask) 
  {
    gdk_gc_set_clip_mask( m_penGC, mask );
    gdk_gc_set_clip_origin( m_penGC, xx, yy );
  };
  
  GdkPixmap *pm = icon.GetPixmap();
  gdk_draw_pixmap( m_window, m_penGC, pm, 0, 0, xx, yy, -1, -1 );
  
  if (useMask && mask) 
  {
    gdk_gc_set_clip_mask( m_penGC, NULL );
    gdk_gc_set_clip_origin( m_penGC, 0, 0 );
  };
};

bool wxPaintDC::Blit( long xdest, long ydest, long width, long height,
       wxDC *source, long xsrc, long ysrc, int WXUNUSED(logical_func), bool WXUNUSED(useMask) )
{
  if (!Ok()) return FALSE;
  
  wxClientDC *csrc = (wxClientDC*)source;

  gdk_window_copy_area ( m_window, m_penGC,
    XLOG2DEV(xdest), YLOG2DEV(ydest),
    csrc->GetWindow(),
    source->DeviceToLogicalX(xsrc), source->DeviceToLogicalY(ysrc),
    source->DeviceToLogicalXRel(width), source->DeviceToLogicalYRel(height) );

/*    
  gdk_window_copy_area ( m_window, m_penGC,
    XLOG2DEV(xdest), YLOG2DEV(ydest),
    csrc->GetWindow(),
    xsrc, ysrc,
    width, height );
*/
    
  return TRUE;
};

void wxPaintDC::DrawText( const wxString &text, long x, long y, bool WXUNUSED(use16) )
{
  if (!Ok()) return;
  
  GdkFont *font = m_font.GetInternalFont( m_scaleY );
  gdk_draw_string( m_window, font, m_textGC, 
    XLOG2DEV(x), 
    YLOG2DEV(y) + font->ascent, text );
};

bool wxPaintDC::CanGetTextExtent(void) const
{
  return TRUE;
};

void wxPaintDC::GetTextExtent( const wxString &string, long *width, long *height,
                     long *WXUNUSED(descent), long *WXUNUSED(externalLeading),
                     wxFont *WXUNUSED(theFont), bool WXUNUSED(use16) )
{
  if (!Ok()) return;
  
  GdkFont *font = m_font.GetInternalFont( m_scaleY );
  if (width) (*width) = gdk_string_width( font, string );
  if (height) (*height) = font->ascent + font->descent;
};

long wxPaintDC::GetCharWidth(void)
{
  if (!Ok()) return 0;
  
  GdkFont *font = m_font.GetInternalFont( m_scaleY );
  return gdk_string_width( font, "H" );
};

long wxPaintDC::GetCharHeight(void)
{
  if (!Ok()) return 0;
  
  GdkFont *font = m_font.GetInternalFont( m_scaleY );
  return font->ascent + font->descent;
};

void wxPaintDC::Clear(void)
{
  if (!Ok()) return;
  
  DestroyClippingRegion();
  gdk_window_clear( m_window );
};

void wxPaintDC::SetFont( const wxFont &font )
{
  if (!Ok()) return;
  
  m_font = font;
};

void wxPaintDC::SetPen( const wxPen &pen )
{
  if (!Ok()) return;

  if (m_pen == pen) return;
  
  m_pen = pen;
  
  if (!m_pen.Ok()) return;
  
  gint width = m_pen.GetWidth();
  
  GdkLineStyle lineStyle = GDK_LINE_SOLID;
  switch (m_pen.GetStyle())
  {
    case wxSOLID:      { lineStyle = GDK_LINE_SOLID;       break; };
    case wxDOT:        { lineStyle = GDK_LINE_ON_OFF_DASH; break; };
    case wxLONG_DASH:  { lineStyle = GDK_LINE_ON_OFF_DASH; break; };
    case wxSHORT_DASH: { lineStyle = GDK_LINE_ON_OFF_DASH; break; };
    case wxDOT_DASH:   { lineStyle = GDK_LINE_DOUBLE_DASH; break; };
  };
  
  GdkCapStyle capStyle = GDK_CAP_ROUND;
  switch (m_pen.GetCap())
  {
    case wxCAP_ROUND:      { capStyle = GDK_CAP_ROUND;      break; };
    case wxCAP_PROJECTING: { capStyle = GDK_CAP_PROJECTING; break; };
    case wxCAP_BUTT:       { capStyle = GDK_CAP_BUTT;       break; };
  };
  
  GdkJoinStyle joinStyle = GDK_JOIN_ROUND;
  switch (m_pen.GetJoin())
  {
    case wxJOIN_BEVEL: { joinStyle = GDK_JOIN_BEVEL; break; };
    case wxJOIN_ROUND: { joinStyle = GDK_JOIN_ROUND; break; };
    case wxJOIN_MITER: { joinStyle = GDK_JOIN_MITER; break; };
  };
  
  gdk_gc_set_line_attributes( m_penGC, width, lineStyle, capStyle, joinStyle );
  
  m_pen.GetColour().CalcPixel( m_cmap );
  gdk_gc_set_foreground( m_penGC, m_pen.GetColour().GetColor() );
};

void wxPaintDC::SetBrush( const wxBrush &brush )
{
  if (!Ok()) return;
  
  if (m_brush == brush) return;
  
  m_brush = brush;
  
  if (!m_brush.Ok()) return;
  
  m_brush.GetColour().CalcPixel( m_cmap );
  gdk_gc_set_foreground( m_brushGC, m_brush.GetColour().GetColor() );
  
  GdkFill fillStyle = GDK_SOLID;
  switch (m_brush.GetStyle())
  {
    case wxSOLID:
    case wxTRANSPARENT:
      break;
    default:
      fillStyle = GDK_STIPPLED;
  };
 
  gdk_gc_set_fill( m_brushGC, fillStyle );
  
  if (m_brush.GetStyle() == wxSTIPPLE)
  {
    gdk_gc_set_stipple( m_brushGC, m_brush.GetStipple()->GetPixmap() );
  };
  
  if (IS_HATCH(m_brush.GetStyle()))
  {
    int num = m_brush.GetStyle() - wxBDIAGONAL_HATCH;
    gdk_gc_set_stipple( m_brushGC, hatches[num] );
  };
};

void wxPaintDC::SetLogicalFunction( int function )
{
  if (m_logicalFunction == function) return;
  GdkFunction mode = GDK_COPY;
  switch (function)
  {
    case wxXOR:    mode = GDK_INVERT; break;
    case wxINVERT: mode = GDK_INVERT; break;
    default:       break;
  };
  m_logicalFunction = function;
  gdk_gc_set_function( m_penGC, mode );
  gdk_gc_set_function( m_brushGC, mode );
};

void wxPaintDC::SetTextForeground( const wxColour &col )
{
  if (!Ok()) return;
  
  if (m_textForegroundColour == col) return;
  
  m_textForegroundColour = col;
  if (!m_textForegroundColour.Ok()) return;
  
  m_textForegroundColour.CalcPixel( m_cmap );
  gdk_gc_set_foreground( m_textGC, m_textForegroundColour.GetColor() );
};

void wxPaintDC::SetTextBackground( const wxColour &col )
{
  if (!Ok()) return;
  
  if (m_textBackgroundColour == col) return;
  
  m_textBackgroundColour = col;
  if (!m_textBackgroundColour.Ok()) return;
  
  m_textBackgroundColour.CalcPixel( m_cmap );
  gdk_gc_set_background( m_textGC, m_textBackgroundColour.GetColor() );
};

void wxPaintDC::SetBackgroundMode( int WXUNUSED(mode) )
{
};

void wxPaintDC::SetPalette( const wxPalette& WXUNUSED(palette) )
{
};

void wxPaintDC::SetClippingRegion( long x, long y, long width, long height )
{
  wxDC::SetClippingRegion( x, y, width, height );
  
  GdkRectangle rect;
  rect.x = XLOG2DEV(x);
  rect.y = YLOG2DEV(y);
  rect.width = XLOG2DEV(x+width);
  rect.height = YLOG2DEV(y+height);
  gdk_gc_set_clip_rectangle( m_penGC, &rect );
  gdk_gc_set_clip_rectangle( m_brushGC, &rect );
  gdk_gc_set_clip_rectangle( m_textGC, &rect );
  gdk_gc_set_clip_rectangle( m_bgGC, &rect );
  
};

void wxPaintDC::DestroyClippingRegion(void)
{
  wxDC::DestroyClippingRegion();
  
  gdk_gc_set_clip_rectangle( m_penGC, NULL );
  gdk_gc_set_clip_rectangle( m_brushGC, NULL );
  gdk_gc_set_clip_rectangle( m_textGC, NULL );
  gdk_gc_set_clip_rectangle( m_bgGC, NULL );
};

void wxPaintDC::SetUpDC(void)
{
  m_ok = TRUE;
  m_logicalFunction = wxCOPY;
  m_penGC = gdk_gc_new( m_window );
  m_brushGC = gdk_gc_new( m_window );
  m_textGC = gdk_gc_new( m_window );
  m_bgGC = gdk_gc_new( m_window );
  SetTextForeground( m_textForegroundColour );
  SetTextBackground( m_textBackgroundColour );
  SetPen( m_pen );
  SetFont( m_font );
  SetBrush( m_brush );
  
  gdk_gc_set_background( m_penGC, wxWHITE->GetColor() );
  
  if (!hatch_bitmap) 
  {
    hatch_bitmap    = hatches;
    hatch_bitmap[0] = gdk_bitmap_create_from_data( NULL, bdiag_bits, bdiag_width, bdiag_height );
    hatch_bitmap[1] = gdk_bitmap_create_from_data( NULL, cdiag_bits, cdiag_width, cdiag_height );
    hatch_bitmap[2] = gdk_bitmap_create_from_data( NULL, fdiag_bits, fdiag_width, fdiag_height );
    hatch_bitmap[3] = gdk_bitmap_create_from_data( NULL, cross_bits, cross_width, cross_height );
    hatch_bitmap[4] = gdk_bitmap_create_from_data( NULL, horiz_bits, horiz_width, horiz_height );
    hatch_bitmap[5] = gdk_bitmap_create_from_data( NULL, verti_bits, verti_width, verti_height );
  };
};

GdkWindow *wxPaintDC::GetWindow(void)
{
  return m_window;
};

// ----------------------------------- spline code ----------------------------------------

void wx_quadratic_spline(double a1, double b1, double a2, double b2,
                         double a3, double b3, double a4, double b4);
void wx_clear_stack(void);
int wx_spline_pop(double *x1, double *y1, double *x2, double *y2, double *x3,
        double *y3, double *x4, double *y4);
void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3,
          double x4, double y4);
static bool wx_spline_add_point(double x, double y);
static void wx_spline_draw_point_array(wxDC *dc);

wxList wx_spline_point_list;

#define		half(z1, z2)	((z1+z2)/2.0)
#define		THRESHOLD	5

/* iterative version */

void wx_quadratic_spline(double a1, double b1, double a2, double b2, double a3, double b3, double a4,
                 double b4)
{
    register double  xmid, ymid;
    double           x1, y1, x2, y2, x3, y3, x4, y4;

    wx_clear_stack();
    wx_spline_push(a1, b1, a2, b2, a3, b3, a4, b4);

    while (wx_spline_pop(&x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)) {
        xmid = (double)half(x2, x3);
        ymid = (double)half(y2, y3);
	if (fabs(x1 - xmid) < THRESHOLD && fabs(y1 - ymid) < THRESHOLD &&
	    fabs(xmid - x4) < THRESHOLD && fabs(ymid - y4) < THRESHOLD) {
            wx_spline_add_point( x1, y1 );
            wx_spline_add_point( xmid, ymid );
	} else {
            wx_spline_push(xmid, ymid, (double)half(xmid, x3), (double)half(ymid, y3),
                 (double)half(x3, x4), (double)half(y3, y4), x4, y4);
            wx_spline_push(x1, y1, (double)half(x1, x2), (double)half(y1, y2),
                 (double)half(x2, xmid), (double)half(y2, ymid), xmid, ymid);
	}
    }
}

/* utilities used by spline drawing routines */

typedef struct wx_spline_stack_struct {
    double           x1, y1, x2, y2, x3, y3, x4, y4;
} Stack;

#define         SPLINE_STACK_DEPTH             20
static Stack    wx_spline_stack[SPLINE_STACK_DEPTH];
static Stack   *wx_stack_top;
static int      wx_stack_count;

void wx_clear_stack(void)
{
    wx_stack_top = wx_spline_stack;
    wx_stack_count = 0;
}

void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4)
{
    wx_stack_top->x1 = x1;
    wx_stack_top->y1 = y1;
    wx_stack_top->x2 = x2;
    wx_stack_top->y2 = y2;
    wx_stack_top->x3 = x3;
    wx_stack_top->y3 = y3;
    wx_stack_top->x4 = x4;
    wx_stack_top->y4 = y4;
    wx_stack_top++;
    wx_stack_count++;
}

int wx_spline_pop(double *x1, double *y1, double *x2, double *y2,
                  double *x3, double *y3, double *x4, double *y4)
{
    if (wx_stack_count == 0)
	return (0);
    wx_stack_top--;
    wx_stack_count--;
    *x1 = wx_stack_top->x1;
    *y1 = wx_stack_top->y1;
    *x2 = wx_stack_top->x2;
    *y2 = wx_stack_top->y2;
    *x3 = wx_stack_top->x3;
    *y3 = wx_stack_top->y3;
    *x4 = wx_stack_top->x4;
    *y4 = wx_stack_top->y4;
    return (1);
}

static bool wx_spline_add_point(double x, double y)
{
  wxPoint *point = new wxPoint ;
  point->x = (int) x;
  point->y = (int) y;
  wx_spline_point_list.Append((wxObject*)point);
  return TRUE;
}

static void wx_spline_draw_point_array(wxDC *dc)
{
  dc->DrawLines(&wx_spline_point_list, 0, 0 );
  wxNode *node = wx_spline_point_list.First();
  while (node)
  {
    wxPoint *point = (wxPoint *)node->Data();
    delete point;
    delete node;
    node = wx_spline_point_list.First();
  }
}

void wxPaintDC::DrawOpenSpline( wxList *points )
{
    wxPoint *p;
    double           cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4;
    double           x1, y1, x2, y2;

    wxNode *node = points->First();
    p = (wxPoint *)node->Data();

    x1 = p->x;
    y1 = p->y;

    node = node->Next();
    p = (wxPoint *)node->Data();

    x2 = p->x;
    y2 = p->y;
    cx1 = (double)((x1 + x2) / 2);
    cy1 = (double)((y1 + y2) / 2);
    cx2 = (double)((cx1 + x2) / 2);
    cy2 = (double)((cy1 + y2) / 2);

    wx_spline_add_point(x1, y1);

    while ((node = node->Next()) != NULL)
    {
        p = (wxPoint *)node->Data();
	x1 = x2;
	y1 = y2;
	x2 = p->x;
	y2 = p->y;
        cx4 = (double)(x1 + x2) / 2;
        cy4 = (double)(y1 + y2) / 2;
        cx3 = (double)(x1 + cx4) / 2;
        cy3 = (double)(y1 + cy4) / 2;

        wx_quadratic_spline(cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4);

	cx1 = cx4;
	cy1 = cy4;
        cx2 = (double)(cx1 + x2) / 2;
        cy2 = (double)(cy1 + y2) / 2;
    }

    wx_spline_add_point( cx1, cy1 );
    wx_spline_add_point( x2, y2 );

    wx_spline_draw_point_array( this );
};