src/common/dcbase.cpp

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