src/common/dcbase.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/dcbase.cpp
   3 // Purpose:     generic methods of the wxDC Class
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     05/25/99
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) wxWidgets team
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #include "wx/dc.h"
  28 #include "wx/dcbuffer.h" // for IMPLEMENT_DYNAMIC_CLASS
  29
  30 #ifndef WX_PRECOMP
  31     #include "wx/math.h"
  32 #endif
  33
  34 // bool wxDCBase::sm_cacheing = false;
  35
  36 IMPLEMENT_ABSTRACT_CLASS(wxDCBase, wxObject)
  37
  38 // ============================================================================
  39 // implementation
  40 // ============================================================================
  41
  42 IMPLEMENT_DYNAMIC_CLASS(wxBufferedDC, wxMemoryDC)
  43 IMPLEMENT_ABSTRACT_CLASS(wxBufferedPaintDC, wxBufferedDC)
  44
  45 #if WXWIN_COMPATIBILITY_2_6
  46 void wxDCBase::BeginDrawing()
  47 {
  48 }
  49
  50 void wxDCBase::EndDrawing()
  51 {
  52 }
  53 #endif // WXWIN_COMPATIBILITY_2_6
  54
  55 // ----------------------------------------------------------------------------
  56 // special symbols
  57 // ----------------------------------------------------------------------------
  58
  59 void wxDCBase::DoDrawCheckMark(wxCoord x1, wxCoord y1,
  60                                wxCoord width, wxCoord height)
  61 {
  62     wxCHECK_RET( Ok(), wxT("invalid window dc") );
  63
  64     wxCoord x2 = x1 + width,
  65             y2 = y1 + height;
  66
  67     // this is to yield width of 3 for width == height == 10
  68     SetPen(wxPen(GetTextForeground(), (width + height + 1) / 7, wxSOLID));
  69
  70     // we're drawing a scaled version of wx/generic/tick.xpm here
  71     wxCoord x3 = x1 + (4*width) / 10,   // x of the tick bottom
  72             y3 = y1 + height / 2;       // y of the left tick branch
  73     DoDrawLine(x1, y3, x3, y2);
  74     DoDrawLine(x3, y2, x2, y1);
  75
  76     CalcBoundingBox(x1, y1);
  77     CalcBoundingBox(x2, y2);
  78 }
  79
  80 // ----------------------------------------------------------------------------
  81 // line/polygons
  82 // ----------------------------------------------------------------------------
  83
  84 void wxDCBase::DrawLines(const wxList *list, wxCoord xoffset, wxCoord yoffset)
  85 {
  86     int n = list->GetCount();
  87     wxPoint *points = new wxPoint[n];
  88
  89     int i = 0;
  90     for ( wxList::compatibility_iterator node = list->GetFirst(); node; node = node->GetNext(), i++ )
  91     {
  92         wxPoint *point = (wxPoint *)node->GetData();
  93         points[i].x = point->x;
  94         points[i].y = point->y;
  95     }
  96
  97     DoDrawLines(n, points, xoffset, yoffset);
  98
  99     delete [] points;
 100 }
 101
 102
 103 void wxDCBase::DrawPolygon(const wxList *list,
 104                            wxCoord xoffset, wxCoord yoffset,
 105                            int fillStyle)
 106 {
 107     int n = list->GetCount();
 108     wxPoint *points = new wxPoint[n];
 109
 110     int i = 0;
 111     for ( wxList::compatibility_iterator node = list->GetFirst(); node; node = node->GetNext(), i++ )
 112     {
 113         wxPoint *point = (wxPoint *)node->GetData();
 114         points[i].x = point->x;
 115         points[i].y = point->y;
 116     }
 117
 118     DoDrawPolygon(n, points, xoffset, yoffset, fillStyle);
 119
 120     delete [] points;
 121 }
 122
 123 void
 124 wxDCBase::DoDrawPolyPolygon(int n,
 125                             int count[],
 126                             wxPoint points[],
 127                             wxCoord xoffset, wxCoord yoffset,
 128                             int fillStyle)
 129 {
 130     if ( n == 1 )
 131     {
 132         DoDrawPolygon(count[0], points, xoffset, yoffset, fillStyle);
 133         return;
 134     }
 135
 136     int      i, j, lastOfs;
 137     wxPoint* pts;
 138     wxPen    pen;
 139
 140     for (i = j = lastOfs = 0; i < n; i++)
 141     {
 142         lastOfs = j;
 143         j      += count[i];
 144     }
 145     pts = new wxPoint[j+n-1];
 146     for (i = 0; i < j; i++)
 147         pts[i] = points[i];
 148     for (i = 2; i <= n; i++)
 149     {
 150         lastOfs -= count[n-i];
 151         pts[j++] = pts[lastOfs];
 152     }
 153
 154     pen = GetPen();
 155     SetPen(wxPen(*wxBLACK, 0, wxTRANSPARENT));
 156     DoDrawPolygon(j, pts, xoffset, yoffset, fillStyle);
 157     SetPen(pen);
 158     for (i = j = 0; i < n; i++)
 159     {
 160         DoDrawLines(count[i], pts+j, xoffset, yoffset);
 161         j += count[i];
 162     }
 163     delete[] pts;
 164 }
 165
 166 // ----------------------------------------------------------------------------
 167 // splines
 168 // ----------------------------------------------------------------------------
 169
 170 #if wxUSE_SPLINES
 171
 172 // TODO: this API needs fixing (wxPointList, why (!const) "wxList *"?)
 173 void wxDCBase::DrawSpline(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2, wxCoord x3, wxCoord y3)
 174 {
 175     wxList point_list;
 176
 177     wxPoint *point1 = new wxPoint;
 178     point1->x = x1; point1->y = y1;
 179     point_list.Append((wxObject*)point1);
 180
 181     wxPoint *point2 = new wxPoint;
 182     point2->x = x2; point2->y = y2;
 183     point_list.Append((wxObject*)point2);
 184
 185     wxPoint *point3 = new wxPoint;
 186     point3->x = x3; point3->y = y3;
 187     point_list.Append((wxObject*)point3);
 188
 189     DrawSpline(&point_list);
 190
 191     for( wxList::compatibility_iterator node = point_list.GetFirst(); node; node = node->GetNext() )
 192     {
 193         wxPoint *p = (wxPoint *)node->GetData();
 194         delete p;
 195     }
 196 }
 197
 198 void wxDCBase::DrawSpline(int n, wxPoint points[])
 199 {
 200     wxList list;
 201     for (int i =0; i < n; i++)
 202     {
 203         list.Append((wxObject*)&points[i]);
 204     }
 205
 206     DrawSpline(&list);
 207 }
 208
 209 // ----------------------------------- spline code ----------------------------------------
 210
 211 void wx_quadratic_spline(double a1, double b1, double a2, double b2,
 212                          double a3, double b3, double a4, double b4);
 213 void wx_clear_stack();
 214 int wx_spline_pop(double *x1, double *y1, double *x2, double *y2, double *x3,
 215         double *y3, double *x4, double *y4);
 216 void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3,
 217           double x4, double y4);
 218 static bool wx_spline_add_point(double x, double y);
 219 static void wx_spline_draw_point_array(wxDCBase *dc);
 220
 221 wxList wx_spline_point_list;
 222
 223 #define                half(z1, z2)        ((z1+z2)/2.0)
 224 #define                THRESHOLD        5
 225
 226 /* iterative version */
 227
 228 void wx_quadratic_spline(double a1, double b1, double a2, double b2, double a3, double b3, double a4,
 229                  double b4)
 230 {
 231     register double  xmid, ymid;
 232     double           x1, y1, x2, y2, x3, y3, x4, y4;
 233
 234     wx_clear_stack();
 235     wx_spline_push(a1, b1, a2, b2, a3, b3, a4, b4);
 236
 237     while (wx_spline_pop(&x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)) {
 238         xmid = (double)half(x2, x3);
 239         ymid = (double)half(y2, y3);
 240         if (fabs(x1 - xmid) < THRESHOLD && fabs(y1 - ymid) < THRESHOLD &&
 241             fabs(xmid - x4) < THRESHOLD && fabs(ymid - y4) < THRESHOLD) {
 242             wx_spline_add_point( x1, y1 );
 243             wx_spline_add_point( xmid, ymid );
 244         } else {
 245             wx_spline_push(xmid, ymid, (double)half(xmid, x3), (double)half(ymid, y3),
 246                  (double)half(x3, x4), (double)half(y3, y4), x4, y4);
 247             wx_spline_push(x1, y1, (double)half(x1, x2), (double)half(y1, y2),
 248                  (double)half(x2, xmid), (double)half(y2, ymid), xmid, ymid);
 249         }
 250     }
 251 }
 252
 253 /* utilities used by spline drawing routines */
 254
 255 typedef struct wx_spline_stack_struct {
 256     double           x1, y1, x2, y2, x3, y3, x4, y4;
 257 } Stack;
 258
 259 #define         SPLINE_STACK_DEPTH             20
 260 static Stack    wx_spline_stack[SPLINE_STACK_DEPTH];
 261 static Stack   *wx_stack_top;
 262 static int      wx_stack_count;
 263
 264 void wx_clear_stack()
 265 {
 266     wx_stack_top = wx_spline_stack;
 267     wx_stack_count = 0;
 268 }
 269
 270 void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4)
 271 {
 272     wx_stack_top->x1 = x1;
 273     wx_stack_top->y1 = y1;
 274     wx_stack_top->x2 = x2;
 275     wx_stack_top->y2 = y2;
 276     wx_stack_top->x3 = x3;
 277     wx_stack_top->y3 = y3;
 278     wx_stack_top->x4 = x4;
 279     wx_stack_top->y4 = y4;
 280     wx_stack_top++;
 281     wx_stack_count++;
 282 }
 283
 284 int wx_spline_pop(double *x1, double *y1, double *x2, double *y2,
 285                   double *x3, double *y3, double *x4, double *y4)
 286 {
 287     if (wx_stack_count == 0)
 288         return (0);
 289     wx_stack_top--;
 290     wx_stack_count--;
 291     *x1 = wx_stack_top->x1;
 292     *y1 = wx_stack_top->y1;
 293     *x2 = wx_stack_top->x2;
 294     *y2 = wx_stack_top->y2;
 295     *x3 = wx_stack_top->x3;
 296     *y3 = wx_stack_top->y3;
 297     *x4 = wx_stack_top->x4;
 298     *y4 = wx_stack_top->y4;
 299     return (1);
 300 }
 301
 302 static bool wx_spline_add_point(double x, double y)
 303 {
 304   wxPoint *point = new wxPoint ;
 305   point->x = (int) x;
 306   point->y = (int) y;
 307   wx_spline_point_list.Append((wxObject*)point);
 308   return true;
 309 }
 310
 311 static void wx_spline_draw_point_array(wxDCBase *dc)
 312 {
 313   dc->DrawLines(&wx_spline_point_list, 0, 0 );
 314   wxList::compatibility_iterator node = wx_spline_point_list.GetFirst();
 315   while (node)
 316   {
 317     wxPoint *point = (wxPoint *)node->GetData();
 318     delete point;
 319     wx_spline_point_list.Erase(node);
 320     node = wx_spline_point_list.GetFirst();
 321   }
 322 }
 323
 324 void wxDCBase::DoDrawSpline( wxList *points )
 325 {
 326     wxCHECK_RET( Ok(), wxT("invalid window dc") );
 327
 328     wxPoint *p;
 329     double           cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4;
 330     double           x1, y1, x2, y2;
 331
 332     wxList::compatibility_iterator node = points->GetFirst();
 333     if (!node)
 334         // empty list
 335         return;
 336
 337     p = (wxPoint *)node->GetData();
 338
 339     x1 = p->x;
 340     y1 = p->y;
 341
 342     node = node->GetNext();
 343     p = (wxPoint *)node->GetData();
 344
 345     x2 = p->x;
 346     y2 = p->y;
 347     cx1 = (double)((x1 + x2) / 2);
 348     cy1 = (double)((y1 + y2) / 2);
 349     cx2 = (double)((cx1 + x2) / 2);
 350     cy2 = (double)((cy1 + y2) / 2);
 351
 352     wx_spline_add_point(x1, y1);
 353
 354     while ((node = node->GetNext())
 355 #if !wxUSE_STL
 356            != NULL
 357 #endif // !wxUSE_STL
 358           )
 359     {
 360         p = (wxPoint *)node->GetData();
 361         x1 = x2;
 362         y1 = y2;
 363         x2 = p->x;
 364         y2 = p->y;
 365         cx4 = (double)(x1 + x2) / 2;
 366         cy4 = (double)(y1 + y2) / 2;
 367         cx3 = (double)(x1 + cx4) / 2;
 368         cy3 = (double)(y1 + cy4) / 2;
 369
 370         wx_quadratic_spline(cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4);
 371
 372         cx1 = cx4;
 373         cy1 = cy4;
 374         cx2 = (double)(cx1 + x2) / 2;
 375         cy2 = (double)(cy1 + y2) / 2;
 376     }
 377
 378     wx_spline_add_point( cx1, cy1 );
 379     wx_spline_add_point( x2, y2 );
 380
 381     wx_spline_draw_point_array( this );
 382 }
 383
 384 #endif // wxUSE_SPLINES
 385
 386 // ----------------------------------------------------------------------------
 387 // Partial Text Extents
 388 // ----------------------------------------------------------------------------
 389
 390
 391 // Each element of the widths array will be the width of the string up to and
 392 // including the corresponding character in text.  This is the generic
 393 // implementation, the port-specific classes should do this with native APIs
 394 // if available and if faster.  Note: pango_layout_index_to_pos is much slower
 395 // than calling GetTextExtent!!
 396
 397 #define FWC_SIZE 256
 398
 399 class FontWidthCache
 400 {
 401 public:
 402     FontWidthCache() : m_scaleX(1), m_widths(NULL) { }
 403     ~FontWidthCache() { delete []m_widths; }
 404
 405     void Reset()
 406     {
 407         if (!m_widths)
 408             m_widths = new int[FWC_SIZE];
 409
 410         memset(m_widths, 0, sizeof(int)*FWC_SIZE);
 411     }
 412
 413     wxFont m_font;
 414     double m_scaleX;
 415     int *m_widths;
 416 };
 417
 418 static FontWidthCache s_fontWidthCache;
 419
 420 bool wxDCBase::DoGetPartialTextExtents(const wxString& text, wxArrayInt& widths) const
 421 {
 422     int totalWidth = 0;
 423
 424     const size_t len = text.length();
 425     widths.Empty();
 426     widths.Add(0, len);
 427
 428     // reset the cache if font or horizontal scale have changed
 429     if ( !s_fontWidthCache.m_widths ||
 430          !wxIsSameDouble(s_fontWidthCache.m_scaleX, m_scaleX) ||
 431          (s_fontWidthCache.m_font != GetFont()) )
 432     {
 433         s_fontWidthCache.Reset();
 434         s_fontWidthCache.m_font = GetFont();
 435         s_fontWidthCache.m_scaleX = m_scaleX;
 436     }
 437
 438     // Calculate the position of each character based on the widths of
 439     // the previous characters
 440     int w, h;
 441     for ( size_t i = 0; i < len; i++ )
 442     {
 443         const wxChar c = text[i];
 444         unsigned int c_int = (unsigned int)c;
 445
 446         if ((c_int < FWC_SIZE) && (s_fontWidthCache.m_widths[c_int] != 0))
 447         {
 448             w = s_fontWidthCache.m_widths[c_int];
 449         }
 450         else
 451         {
 452             GetTextExtent(c, &w, &h);
 453             if (c_int < FWC_SIZE)
 454                 s_fontWidthCache.m_widths[c_int] = w;
 455         }
 456
 457         totalWidth += w;
 458         widths[i] = totalWidth;
 459     }
 460
 461     return true;
 462 }
 463
 464
 465 // ----------------------------------------------------------------------------
 466 // enhanced text drawing
 467 // ----------------------------------------------------------------------------
 468
 469 void wxDCBase::GetMultiLineTextExtent(const wxString& text,
 470                                       wxCoord *x,
 471                                       wxCoord *y,
 472                                       wxCoord *h,
 473                                       wxFont *font)
 474 {
 475     wxCoord widthTextMax = 0, widthLine,
 476             heightTextTotal = 0, heightLineDefault = 0, heightLine = 0;
 477
 478     wxString curLine;
 479     for ( const wxChar *pc = text; ; pc++ )
 480     {
 481         if ( *pc == _T('\n') || *pc == _T('\0') )
 482         {
 483             if ( curLine.empty() )
 484             {
 485                 // we can't use GetTextExtent - it will return 0 for both width
 486                 // and height and an empty line should count in height
 487                 // calculation
 488
 489                 // assume that this line has the same height as the previous
 490                 // one
 491                 if ( !heightLineDefault )
 492                     heightLineDefault = heightLine;
 493
 494                 if ( !heightLineDefault )
 495                 {
 496                     // but we don't know it yet - choose something reasonable
 497                     GetTextExtent(_T("W"), NULL, &heightLineDefault,
 498                                   NULL, NULL, font);
 499                 }
 500
 501                 heightTextTotal += heightLineDefault;
 502             }
 503             else
 504             {
 505                 GetTextExtent(curLine, &widthLine, &heightLine,
 506                               NULL, NULL, font);
 507                 if ( widthLine > widthTextMax )
 508                     widthTextMax = widthLine;
 509                 heightTextTotal += heightLine;
 510             }
 511
 512             if ( *pc == _T('\n') )
 513             {
 514                curLine.clear();
 515             }
 516             else
 517             {
 518                // the end of string
 519                break;
 520             }
 521         }
 522         else
 523         {
 524             curLine += *pc;
 525         }
 526     }
 527
 528     if ( x )
 529         *x = widthTextMax;
 530     if ( y )
 531         *y = heightTextTotal;
 532     if ( h )
 533         *h = heightLine;
 534 }
 535
 536 void wxDCBase::DrawLabel(const wxString& text,
 537                          const wxBitmap& bitmap,
 538                          const wxRect& rect,
 539                          int alignment,
 540                          int indexAccel,
 541                          wxRect *rectBounding)
 542 {
 543     // find the text position
 544     wxCoord widthText, heightText, heightLine;
 545     GetMultiLineTextExtent(text, &widthText, &heightText, &heightLine);
 546
 547     wxCoord width, height;
 548     if ( bitmap.Ok() )
 549     {
 550         width = widthText + bitmap.GetWidth();
 551         height = bitmap.GetHeight();
 552     }
 553     else // no bitmap
 554     {
 555         width = widthText;
 556         height = heightText;
 557     }
 558
 559     wxCoord x, y;
 560     if ( alignment & wxALIGN_RIGHT )
 561     {
 562         x = rect.GetRight() - width;
 563     }
 564     else if ( alignment & wxALIGN_CENTRE_HORIZONTAL )
 565     {
 566         x = (rect.GetLeft() + rect.GetRight() + 1 - width) / 2;
 567     }
 568     else // alignment & wxALIGN_LEFT
 569     {
 570         x = rect.GetLeft();
 571     }
 572
 573     if ( alignment & wxALIGN_BOTTOM )
 574     {
 575         y = rect.GetBottom() - height;
 576     }
 577     else if ( alignment & wxALIGN_CENTRE_VERTICAL )
 578     {
 579         y = (rect.GetTop() + rect.GetBottom() + 1 - height) / 2;
 580     }
 581     else // alignment & wxALIGN_TOP
 582     {
 583         y = rect.GetTop();
 584     }
 585
 586     // draw the bitmap first
 587     wxCoord x0 = x,
 588             y0 = y,
 589             width0 = width;
 590     if ( bitmap.Ok() )
 591     {
 592         DrawBitmap(bitmap, x, y, true /* use mask */);
 593
 594         wxCoord offset = bitmap.GetWidth() + 4;
 595         x += offset;
 596         width -= offset;
 597
 598         y += (height - heightText) / 2;
 599     }
 600
 601     // we will draw the underscore under the accel char later
 602     wxCoord startUnderscore = 0,
 603             endUnderscore = 0,
 604             yUnderscore = 0;
 605
 606     // split the string into lines and draw each of them separately
 607     wxString curLine;
 608     for ( const wxChar *pc = text; ; pc++ )
 609     {
 610         if ( *pc == _T('\n') || *pc == _T('\0') )
 611         {
 612             int xRealStart = x; // init it here to avoid compielr warnings
 613
 614             if ( !curLine.empty() )
 615             {
 616                 // NB: can't test for !(alignment & wxALIGN_LEFT) because
 617                 //     wxALIGN_LEFT is 0
 618                 if ( alignment & (wxALIGN_RIGHT | wxALIGN_CENTRE_HORIZONTAL) )
 619                 {
 620                     wxCoord widthLine;
 621                     GetTextExtent(curLine, &widthLine, NULL);
 622
 623                     if ( alignment & wxALIGN_RIGHT )
 624                     {
 625                         xRealStart += width - widthLine;
 626                     }
 627                     else // if ( alignment & wxALIGN_CENTRE_HORIZONTAL )
 628                     {
 629                         xRealStart += (width - widthLine) / 2;
 630                     }
 631                 }
 632                 //else: left aligned, nothing to do
 633
 634                 DrawText(curLine, xRealStart, y);
 635             }
 636
 637             y += heightLine;
 638
 639             // do we have underscore in this line? we can check yUnderscore
 640             // because it is set below to just y + heightLine if we do
 641             if ( y == yUnderscore )
 642             {
 643                 // adjust the horz positions to account for the shift
 644                 startUnderscore += xRealStart;
 645                 endUnderscore += xRealStart;
 646             }
 647
 648             if ( *pc == _T('\0') )
 649                 break;
 650
 651             curLine.clear();
 652         }
 653         else // not end of line
 654         {
 655             if ( pc - text.c_str() == indexAccel )
 656             {
 657                 // remeber to draw underscore here
 658                 GetTextExtent(curLine, &startUnderscore, NULL);
 659                 curLine += *pc;
 660                 GetTextExtent(curLine, &endUnderscore, NULL);
 661
 662                 yUnderscore = y + heightLine;
 663             }
 664             else
 665             {
 666                 curLine += *pc;
 667             }
 668         }
 669     }
 670
 671     // draw the underscore if found
 672     if ( startUnderscore != endUnderscore )
 673     {
 674         // it should be of the same colour as text
 675         SetPen(wxPen(GetTextForeground(), 0, wxSOLID));
 676
 677         yUnderscore--;
 678
 679         DrawLine(startUnderscore, yUnderscore, endUnderscore, yUnderscore);
 680     }
 681
 682     // return bounding rect if requested
 683     if ( rectBounding )
 684     {
 685         *rectBounding = wxRect(x, y - heightText, widthText, heightText);
 686     }
 687
 688     CalcBoundingBox(x0, y0);
 689     CalcBoundingBox(x0 + width0, y0 + height);
 690 }
 691
 692
 693 void wxDCBase::DoGradientFillLinear(const wxRect& rect,
 694                                     const wxColour& initialColour,
 695                                     const wxColour& destColour,
 696                                     wxDirection nDirection)
 697 {
 698     // save old pen
 699     wxPen oldPen = m_pen;
 700
 701     wxUint8 nR1 = destColour.Red();
 702     wxUint8 nG1 = destColour.Green();
 703     wxUint8 nB1 = destColour.Blue();
 704     wxUint8 nR2 = initialColour.Red();
 705     wxUint8 nG2 = initialColour.Green();
 706     wxUint8 nB2 = initialColour.Blue();
 707     wxUint8 nR, nG, nB;
 708
 709     if ( nDirection == wxEAST || nDirection == wxWEST )
 710     {
 711         wxInt32 x = rect.GetWidth();
 712         wxInt32 w = x;              // width of area to shade
 713         wxInt32 xDelta = w/256;     // height of one shade bend
 714         if (xDelta < 1)
 715             xDelta = 1;
 716
 717         while (x >= xDelta)
 718         {
 719             x -= xDelta;
 720             if (nR1 > nR2)
 721                 nR = nR1 - (nR1-nR2)*(w-x)/w;
 722             else
 723                 nR = nR1 + (nR2-nR1)*(w-x)/w;
 724
 725             if (nG1 > nG2)
 726                 nG = nG1 - (nG1-nG2)*(w-x)/w;
 727             else
 728                 nG = nG1 + (nG2-nG1)*(w-x)/w;
 729
 730             if (nB1 > nB2)
 731                 nB = nB1 - (nB1-nB2)*(w-x)/w;
 732             else
 733                 nB = nB1 + (nB2-nB1)*(w-x)/w;
 734
 735             SetPen(wxPen(wxColour(nR, nG, nB), 1, wxSOLID));
 736             if(nDirection == wxEAST)
 737                 DrawRectangle(rect.GetLeft()+x, rect.GetTop(),
 738                         xDelta, rect.GetHeight());
 739             else //nDirection == wxWEST
 740                 DrawRectangle(rect.GetRight()-x-xDelta, rect.GetTop(),
 741                         xDelta, rect.GetHeight());
 742         }
 743     }
 744     else  // nDirection == wxNORTH || nDirection == wxSOUTH
 745     {
 746         wxInt32 y = rect.GetHeight();
 747         wxInt32 w = y;              // height of area to shade
 748         wxInt32 yDelta = w/255;     // height of one shade bend
 749         if (yDelta < 1)
 750             yDelta = 1;
 751
 752         while (y > 0)
 753         {
 754             y -= yDelta;
 755             if (nR1 > nR2)
 756                 nR = nR1 - (nR1-nR2)*(w-y)/w;
 757             else
 758                 nR = nR1 + (nR2-nR1)*(w-y)/w;
 759
 760             if (nG1 > nG2)
 761                 nG = nG1 - (nG1-nG2)*(w-y)/w;
 762             else
 763                 nG = nG1 + (nG2-nG1)*(w-y)/w;
 764
 765             if (nB1 > nB2)
 766                 nB = nB1 - (nB1-nB2)*(w-y)/w;
 767             else
 768                 nB = nB1 + (nB2-nB1)*(w-y)/w;
 769
 770             SetPen(wxPen(wxColour(nR, nG, nB), 1, wxSOLID));
 771             if(nDirection == wxNORTH)
 772                 DrawRectangle(rect.GetLeft(), rect.GetTop()+y,
 773                         rect.GetWidth(), yDelta);
 774             else //nDirection == wxSOUTH
 775                 DrawRectangle(rect.GetLeft(), rect.GetBottom()-y-yDelta,
 776                         rect.GetWidth(), yDelta);
 777         }
 778     }
 779
 780     SetPen(oldPen);
 781 }
 782
 783 void wxDCBase::DoGradientFillConcentric(const wxRect& rect,
 784                                       const wxColour& initialColour,
 785                                       const wxColour& destColour,
 786                                       const wxPoint& circleCenter)
 787 {
 788     //save the old pen color
 789     wxColour oldPenColour = m_pen.GetColour();
 790
 791     wxUint8 nR1 = destColour.Red();
 792     wxUint8 nG1 = destColour.Green();
 793     wxUint8 nB1 = destColour.Blue();
 794     wxUint8 nR2 = initialColour.Red();
 795     wxUint8 nG2 = initialColour.Green();
 796     wxUint8 nB2 = initialColour.Blue();
 797     wxUint8 nR, nG, nB;
 798
 799
 800     //Radius
 801     wxInt32 cx = rect.GetWidth() / 2;
 802     wxInt32 cy = rect.GetHeight() / 2;
 803     wxInt32 nRadius;
 804     if (cx < cy)
 805         nRadius = cx;
 806     else
 807         nRadius = cy;
 808
 809     //Offset of circle
 810     wxInt32 nCircleOffX = circleCenter.x - (rect.GetWidth() / 2);
 811     wxInt32 nCircleOffY = circleCenter.y - (rect.GetHeight() / 2);
 812
 813     for ( wxInt32 x = 0; x < rect.GetWidth(); x++ )
 814     {
 815         for ( wxInt32 y = 0; y < rect.GetHeight(); y++ )
 816         {
 817             //get color difference
 818             wxInt32 nGradient = ((nRadius -
 819                                   (wxInt32)sqrt(
 820                                     pow((double)(x - cx - nCircleOffX), 2) +
 821                                     pow((double)(y - cy - nCircleOffY), 2)
 822                                   )) * 100) / nRadius;
 823
 824             //normalize Gradient
 825             if (nGradient < 0 )
 826                 nGradient = 0;
 827
 828             //get dest colors
 829             nR = (wxUint8)(nR1 + ((nR2 - nR1) * nGradient / 100));
 830             nG = (wxUint8)(nG1 + ((nG2 - nG1) * nGradient / 100));
 831             nB = (wxUint8)(nB1 + ((nB2 - nB1) * nGradient / 100));
 832
 833             //set the pixel
 834             m_pen.SetColour(wxColour(nR,nG,nB));
 835             DrawPoint(wxPoint(x + rect.GetLeft(), y + rect.GetTop()));
 836         }
 837     }
 838     //return old pen color
 839     m_pen.SetColour(oldPenColour);
 840 }
 841
 842 /*
 843 Notes for wxWidgets DrawEllipticArcRot(...)
 844
 845 wxDCBase::DrawEllipticArcRot(...) draws a rotated elliptic arc or an ellipse.
 846 It uses wxDCBase::CalculateEllipticPoints(...) and wxDCBase::Rotate(...),
 847 which are also new.
 848
 849 All methods are generic, so they can be implemented in wxDCBase.
 850 DoDrawEllipticArcRot(...) is virtual, so it can be called from deeper
 851 methods like (WinCE) wxDC::DoDrawArc(...).
 852
 853 CalculateEllipticPoints(...) fills a given list of wxPoints with some points
 854 of an elliptic arc. The algorithm is pixel-based: In every row (in flat
 855 parts) or every column (in steep parts) only one pixel is calculated.
 856 Trigonometric calculation (sin, cos, tan, atan) is only done if the
 857 starting angle is not equal to the ending angle. The calculation of the
 858 pixels is done using simple arithmetic only and should perform not too
 859 bad even on devices without floating point processor. I didn't test this yet.
 860
 861 Rotate(...) rotates a list of point pixel-based, you will see rounding errors.
 862 For instance: an ellipse rotated 180 degrees is drawn
 863 slightly different from the original.
 864
 865 The points are then moved to an array and used to draw a polyline and/or polygon
 866 (with center added, the pie).
 867 The result looks quite similar to the native ellipse, only e few pixels differ.
 868
 869 The performance on a desktop system (Athlon 1800, WinXP) is about 7 times
 870 slower as DrawEllipse(...), which calls the native API.
 871 An rotated ellipse outside the clipping region takes nearly the same time,
 872 while an native ellipse outside takes nearly no time to draw.
 873
 874 If you draw an arc with this new method, you will see the starting and ending angles
 875 are calculated properly.
 876 If you use DrawEllipticArc(...), you will see they are only correct for circles
 877 and not properly calculated for ellipses.
 878
 879 Peter Lenhard
 880 p.lenhard@t-online.de
 881 */
 882
 883 #ifdef __WXWINCE__
 884 void wxDCBase::DoDrawEllipticArcRot( wxCoord x, wxCoord y,
 885                                      wxCoord w, wxCoord h,
 886                                      double sa, double ea, double angle )
 887 {
 888     wxList list;
 889
 890     CalculateEllipticPoints( &list, x, y, w, h, sa, ea );
 891     Rotate( &list, angle, wxPoint( x+w/2, y+h/2 ) );
 892
 893     // Add center (for polygon/pie)
 894     list.Append( (wxObject*) new wxPoint( x+w/2, y+h/2 ) );
 895
 896     // copy list into array and delete list elements
 897     int n = list.GetCount();
 898     wxPoint *points = new wxPoint[n];
 899     int i = 0;
 900     wxNode* node = 0;
 901     for ( node = list.GetFirst(); node; node = node->GetNext(), i++ )
 902     {
 903         wxPoint *point = (wxPoint *)node->GetData();
 904         points[i].x = point->x;
 905         points[i].y = point->y;
 906         delete point;
 907     }
 908
 909     // first draw the pie without pen, if necessary
 910     if( GetBrush() != *wxTRANSPARENT_BRUSH )
 911     {
 912         wxPen tempPen( GetPen() );
 913         SetPen( *wxTRANSPARENT_PEN );
 914         DoDrawPolygon( n, points, 0, 0 );
 915         SetPen( tempPen );
 916     }
 917
 918     // then draw the arc without brush, if necessary
 919     if( GetPen() != *wxTRANSPARENT_PEN )
 920     {
 921         // without center
 922         DoDrawLines( n-1, points, 0, 0 );
 923     }
 924
 925     delete [] points;
 926
 927 } // DrawEllipticArcRot
 928
 929 void wxDCBase::Rotate( wxList* points, double angle, wxPoint center )
 930 {
 931     if( angle != 0.0 )
 932     {
 933         double pi(M_PI);
 934         double dSinA = -sin(angle*2.0*pi/360.0);
 935         double dCosA = cos(angle*2.0*pi/360.0);
 936         for ( wxNode* node = points->GetFirst(); node; node = node->GetNext() )
 937         {
 938             wxPoint* point = (wxPoint*)node->GetData();
 939
 940             // transform coordinates, if necessary
 941             if( center.x ) point->x -= center.x;
 942             if( center.y ) point->y -= center.y;
 943
 944             // calculate rotation, rounding simply by implicit cast to integer
 945             int xTemp = point->x * dCosA - point->y * dSinA;
 946             point->y = point->x * dSinA + point->y * dCosA;
 947             point->x = xTemp;
 948
 949             // back transform coordinates, if necessary
 950             if( center.x ) point->x += center.x;
 951             if( center.y ) point->y += center.y;
 952         }
 953     }
 954 }
 955
 956 void wxDCBase::CalculateEllipticPoints( wxList* points,
 957                                         wxCoord xStart, wxCoord yStart,
 958                                         wxCoord w, wxCoord h,
 959                                         double sa, double ea )
 960 {
 961     double pi = M_PI;
 962     double sar = 0;
 963     double ear = 0;
 964     int xsa = 0;
 965     int ysa = 0;
 966     int xea = 0;
 967     int yea = 0;
 968     int sq = 0;
 969     int eq = 0;
 970     bool bUseAngles = false;
 971     if( w<0 ) w = -w;
 972     if( h<0 ) h = -h;
 973     // half-axes
 974     wxCoord a = w/2;
 975     wxCoord b = h/2;
 976     // decrement 1 pixel if ellipse is smaller than 2*a, 2*b
 977     int decrX = 0;
 978     if( 2*a == w ) decrX = 1;
 979     int decrY = 0;
 980     if( 2*b == h ) decrY = 1;
 981     // center
 982     wxCoord xCenter = xStart + a;
 983     wxCoord yCenter = yStart + b;
 984     // calculate data for start and end, if necessary
 985     if( sa != ea )
 986     {
 987         bUseAngles = true;
 988         // normalisation of angles
 989         while( sa<0 ) sa += 360;
 990         while( ea<0 ) ea += 360;
 991         while( sa>=360 ) sa -= 360;
 992         while( ea>=360 ) ea -= 360;
 993         // calculate quadrant numbers
 994         if( sa > 270 ) sq = 3;
 995         else if( sa > 180 ) sq = 2;
 996         else if( sa > 90 ) sq = 1;
 997         if( ea > 270 ) eq = 3;
 998         else if( ea > 180 ) eq = 2;
 999         else if( ea > 90 ) eq = 1;
1000         sar = sa * pi / 180.0;
1001         ear = ea * pi / 180.0;
1002         // correct angle circle -> ellipse
1003         sar = atan( -a/(double)b * tan( sar ) );
1004         if ( sq == 1 || sq == 2 ) sar += pi;
1005         ear = atan( -a/(double)b * tan( ear ) );
1006         if ( eq == 1 || eq == 2 ) ear += pi;
1007         // coordinates of points
1008         xsa = xCenter + a * cos( sar );
1009         if( sq == 0 || sq == 3 ) xsa -= decrX;
1010         ysa = yCenter + b * sin( sar );
1011         if( sq == 2 || sq == 3 ) ysa -= decrY;
1012         xea = xCenter + a * cos( ear );
1013         if( eq == 0 || eq == 3 ) xea -= decrX;
1014         yea = yCenter + b * sin( ear );
1015         if( eq == 2 || eq == 3 ) yea -= decrY;
1016     } // if iUseAngles
1017     // calculate c1 = b^2, c2 = b^2/a^2 with a = w/2, b = h/2
1018     double c1 = b * b;
1019     double c2 = 2.0 / w;
1020     c2 *= c2;
1021     c2 *= c1;
1022     wxCoord x = 0;
1023     wxCoord y = b;
1024     long x2 = 1;
1025     long y2 = y*y;
1026     long y2_old = 0;
1027     long y_old = 0;
1028     // Lists for quadrant 1 to 4
1029     wxList pointsarray[4];
1030     // Calculate points for first quadrant and set in all quadrants
1031     for( x = 0; x <= a; ++x )
1032     {
1033         x2 = x2+x+x-1;
1034         y2_old = y2;
1035         y_old = y;
1036         bool bNewPoint = false;
1037         while( y2 > c1 - c2 * x2 && y > 0 )
1038         {
1039             bNewPoint = true;
1040             y2 = y2-y-y+1;
1041             --y;
1042         }
1043         // old y now to big: set point with old y, old x
1044         if( bNewPoint && x>1)
1045         {
1046             int x1 = x - 1;
1047             // remove points on the same line
1048             pointsarray[0].Insert( (wxObject*) new wxPoint( xCenter + x1 - decrX, yCenter - y_old ) );
1049             pointsarray[1].Append( (wxObject*) new wxPoint( xCenter - x1, yCenter - y_old ) );
1050             pointsarray[2].Insert( (wxObject*) new wxPoint( xCenter - x1, yCenter + y_old - decrY ) );
1051             pointsarray[3].Append( (wxObject*) new wxPoint( xCenter + x1 - decrX, yCenter + y_old - decrY ) );
1052         } // set point
1053     } // calculate point
1054
1055     // Starting and/or ending points for the quadrants, first quadrant gets both.
1056     pointsarray[0].Insert( (wxObject*) new wxPoint( xCenter + a - decrX, yCenter ) );
1057     pointsarray[0].Append( (wxObject*) new wxPoint( xCenter, yCenter - b ) );
1058     pointsarray[1].Append( (wxObject*) new wxPoint( xCenter - a, yCenter ) );
1059     pointsarray[2].Append( (wxObject*) new wxPoint( xCenter, yCenter + b - decrY ) );
1060     pointsarray[3].Append( (wxObject*) new wxPoint( xCenter + a - decrX, yCenter ) );
1061
1062     // copy quadrants in original list
1063     if( bUseAngles )
1064     {
1065         // Copy the right part of the points in the lists
1066         // and delete the wxPoints, because they do not leave this method.
1067         points->Append( (wxObject*) new wxPoint( xsa, ysa ) );
1068         int q = sq;
1069         bool bStarted = false;
1070         bool bReady = false;
1071         bool bForceTurn = ( sq == eq && sa > ea );
1072         while( !bReady )
1073         {
1074             for( wxNode *node = pointsarray[q].GetFirst(); node; node = node->GetNext() )
1075             {
1076                 // once: go to starting point in start quadrant
1077                 if( !bStarted &&
1078                     (
1079                       ( (wxPoint*) node->GetData() )->x < xsa+1 && q <= 1
1080                       ||
1081                       ( (wxPoint*) node->GetData() )->x > xsa-1 && q >= 2
1082                     )
1083                   )
1084                 {
1085                     bStarted = true;
1086                 }
1087
1088                 // copy point, if not at ending point
1089                 if( bStarted )
1090                 {
1091                     if( q != eq || bForceTurn
1092                         ||
1093                         ( (wxPoint*) node->GetData() )->x > xea+1 && q <= 1
1094                         ||
1095                         ( (wxPoint*) node->GetData() )->x < xea-1 && q >= 2
1096                       )
1097                     {
1098                         // copy point
1099                         wxPoint* pPoint = new wxPoint( *((wxPoint*) node->GetData() ) );
1100                         points->Append( (wxObject*) pPoint );
1101                     }
1102                     else if( q == eq && !bForceTurn || ( (wxPoint*) node->GetData() )->x == xea)
1103                     {
1104                         bReady = true;
1105                     }
1106                 }
1107             } // for node
1108             ++q;
1109             if( q > 3 ) q = 0;
1110             bForceTurn = false;
1111             bStarted = true;
1112         } // while not bReady
1113         points->Append( (wxObject*) new wxPoint( xea, yea ) );
1114
1115         // delete points
1116         for( q = 0; q < 4; ++q )
1117         {
1118             for( wxNode *node = pointsarray[q].GetFirst(); node; node = node->GetNext() )
1119             {
1120                 wxPoint *p = (wxPoint *)node->GetData();
1121                 delete p;
1122             }
1123         }
1124     }
1125     else
1126     {
1127         wxNode* node;
1128         // copy whole ellipse, wxPoints will be deleted outside
1129         for( node = pointsarray[0].GetFirst(); node; node = node->GetNext() )
1130         {
1131             wxObject *p = node->GetData();
1132             points->Append( p );
1133         }
1134         for( node = pointsarray[1].GetFirst(); node; node = node->GetNext() )
1135         {
1136             wxObject *p = node->GetData();
1137             points->Append( p );
1138         }
1139         for( node = pointsarray[2].GetFirst(); node; node = node->GetNext() )
1140         {
1141             wxObject *p = node->GetData();
1142             points->Append( p );
1143         }
1144         for( node = pointsarray[3].GetFirst(); node; node = node->GetNext() )
1145         {
1146             wxObject *p = node->GetData();
1147             points->Append( p );
1148         }
1149     } // not iUseAngles
1150 } // CalculateEllipticPoints
1151
1152 #endif