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