contrib/src/ogl/ogldiag.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        ogldiag.cpp
   3 // Purpose:     wxDiagram
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     12/07/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  13 #pragma implementation "ogldiag.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20 #pragma hdrstop
  21 #endif
  22
  23 #ifndef WX_PRECOMP
  24 #include <wx/wx.h>
  25 #endif
  26
  27 #include <wx/wxexpr.h>
  28
  29 #ifdef new
  30 #undef new
  31 #endif
  32
  33 #if wxUSE_IOSTREAMH
  34 #include <iostream.h>
  35 #include <fstream.h>
  36 #else
  37 #include <iostream>
  38 #include <fstream>
  39 #ifdef _MSC_VER
  40 //using namespace std;
  41 #endif
  42 #endif
  43
  44 #include <ctype.h>
  45 #include <math.h>
  46 #include <stdlib.h>
  47
  48 #include <wx/ogl/basic.h>
  49 #include <wx/ogl/basicp.h>
  50 #include <wx/ogl/canvas.h>
  51 #include <wx/ogl/ogldiag.h>
  52 #include <wx/ogl/lines.h>
  53 #include <wx/ogl/composit.h>
  54 #include <wx/ogl/misc.h>
  55
  56 IMPLEMENT_DYNAMIC_CLASS(wxDiagram, wxObject)
  57
  58 // Object canvas
  59 wxDiagram::wxDiagram()
  60 {
  61   m_diagramCanvas = NULL;
  62   m_quickEditMode = FALSE;
  63   m_snapToGrid = TRUE;
  64   m_gridSpacing = 5.0;
  65   m_shapeList = new wxList;
  66   m_mouseTolerance = DEFAULT_MOUSE_TOLERANCE;
  67 }
  68
  69 wxDiagram::~wxDiagram()
  70 {
  71   if (m_shapeList)
  72     delete m_shapeList;
  73 }
  74
  75 void wxDiagram::SetSnapToGrid(bool snap)
  76 {
  77   m_snapToGrid = snap;
  78 }
  79
  80 void wxDiagram::SetGridSpacing(double spacing)
  81 {
  82   m_gridSpacing = spacing;
  83 }
  84
  85 void wxDiagram::Snap(double *x, double *y)
  86 {
  87   if (m_snapToGrid)
  88   {
  89     *x = m_gridSpacing * ((int)(*x/m_gridSpacing + 0.5));
  90     *y = m_gridSpacing * ((int)(*y/m_gridSpacing + 0.5));
  91   }
  92 }
  93
  94
  95 void wxDiagram::Redraw(wxDC& dc)
  96 {
  97   if (m_shapeList)
  98   {
  99     if (GetCanvas())
 100       GetCanvas()->SetCursor(* wxHOURGLASS_CURSOR);
 101     wxNode *current = m_shapeList->First();
 102
 103     while (current)
 104     {
 105       wxShape *object = (wxShape *)current->Data();
 106       if (!object->GetParent())
 107         object->Draw(dc);
 108
 109       current = current->Next();
 110     }
 111     if (GetCanvas())
 112       GetCanvas()->SetCursor(* wxSTANDARD_CURSOR);
 113   }
 114 }
 115
 116 void wxDiagram::Clear(wxDC& dc)
 117 {
 118   dc.Clear();
 119 }
 120
 121 // Insert object after addAfter, or at end of list.
 122 void wxDiagram::AddShape(wxShape *object, wxShape *addAfter)
 123 {
 124   wxNode *nodeAfter = NULL;
 125   if (addAfter)
 126     nodeAfter = m_shapeList->Member(addAfter);
 127
 128   if (!m_shapeList->Member(object))
 129   {
 130     if (nodeAfter)
 131     {
 132       if (nodeAfter->Next())
 133         m_shapeList->Insert(nodeAfter->Next(), object);
 134       else
 135         m_shapeList->Append(object);
 136     }
 137     else
 138       m_shapeList->Append(object);
 139     object->SetCanvas(GetCanvas());
 140   }
 141 }
 142
 143 void wxDiagram::InsertShape(wxShape *object)
 144 {
 145   m_shapeList->Insert(object);
 146   object->SetCanvas(GetCanvas());
 147 }
 148
 149 void wxDiagram::RemoveShape(wxShape *object)
 150 {
 151   m_shapeList->DeleteObject(object);
 152 }
 153
 154 // Should this delete the actual objects too? I think not.
 155 void wxDiagram::RemoveAllShapes()
 156 {
 157   m_shapeList->Clear();
 158 }
 159
 160 void wxDiagram::DeleteAllShapes()
 161 {
 162   wxNode *node = m_shapeList->First();
 163   while (node)
 164   {
 165     wxShape *shape = (wxShape *)node->Data();
 166     if (!shape->GetParent())
 167     {
 168       RemoveShape(shape);
 169       delete shape;
 170       node = m_shapeList->First();
 171     }
 172     else
 173       node = node->Next();
 174   }
 175 }
 176
 177 void wxDiagram::ShowAll(bool show)
 178 {
 179   wxNode *current = m_shapeList->First();
 180
 181   while (current)
 182   {
 183     wxShape *object = (wxShape *)current->Data();
 184     object->Show(show);
 185
 186     current = current->Next();
 187   }
 188 }
 189
 190 void wxDiagram::DrawOutline(wxDC& dc, double x1, double y1, double x2, double y2)
 191 {
 192   wxPen dottedPen(wxColour(0, 0, 0), 1, wxDOT);
 193   dc.SetPen(dottedPen);
 194   dc.SetBrush((* wxTRANSPARENT_BRUSH));
 195
 196   wxPoint points[5];
 197
 198   points[0].x = (int) x1;
 199   points[0].y = (int) y1;
 200
 201   points[1].x = (int) x2;
 202   points[1].y = (int) y1;
 203
 204   points[2].x = (int) x2;
 205   points[2].y = (int) y2;
 206
 207   points[3].x = (int) x1;
 208   points[3].y = (int) y2;
 209
 210   points[4].x = (int) x1;
 211   points[4].y = (int) y1;
 212   dc.DrawLines(5, points);
 213 }
 214
 215 // Make sure all text that should be centred, is centred.
 216 void wxDiagram::RecentreAll(wxDC& dc)
 217 {
 218   wxNode *object_node = m_shapeList->First();
 219   while (object_node)
 220   {
 221     wxShape *obj = (wxShape *)object_node->Data();
 222     obj->Recentre(dc);
 223     object_node = object_node->Next();
 224   }
 225 }
 226
 227 // Input/output
 228 #ifdef PROLOGIO
 229 bool wxDiagram::SaveFile(const wxString& filename)
 230 {
 231   wxBeginBusyCursor();
 232
 233   wxExprDatabase *database = new wxExprDatabase;
 234
 235   // First write the diagram type
 236   wxExpr *header = new wxExpr("diagram");
 237   OnHeaderSave(*database, *header);
 238
 239   database->Append(header);
 240
 241   wxNode *node = m_shapeList->First();
 242   while (node)
 243   {
 244     wxShape *shape = (wxShape *)node->Data();
 245
 246     if (!shape->IsKindOf(CLASSINFO(wxControlPoint)))
 247     {
 248       wxExpr *expr = NULL;
 249       if (shape->IsKindOf(CLASSINFO(wxLineShape)))
 250         expr = new wxExpr("line");
 251        else
 252         expr = new wxExpr("shape");
 253
 254       OnShapeSave(*database, *shape, *expr);
 255     }
 256     node = node->Next();
 257   }
 258   OnDatabaseSave(*database);
 259
 260   wxString tempFile;
 261   wxGetTempFileName(wxT("diag"), tempFile);
 262   FILE* file = fopen(tempFile.mb_str(wxConvFile), "w");
 263   if (! file)
 264   {
 265     wxEndBusyCursor();
 266     delete database;
 267     return FALSE;
 268   }
 269
 270   database->Write(file);
 271   fclose(file);
 272   delete database;
 273
 274 /*
 275   // Save backup
 276   if (FileExists(filename))
 277   {
 278     char buf[400];
 279 #ifdef __X__
 280     sprintf(buf, "%s.bak", filename);
 281 #endif
 282 #ifdef __WXMSW__
 283     sprintf(buf, "_diagram.bak");
 284 #endif
 285     if (FileExists(buf)) wxRemoveFile(buf);
 286     if (!wxRenameFile(filename, buf))
 287     {
 288       wxCopyFile(filename, buf);
 289       wxRemoveFile(filename);
 290     }
 291   }
 292 */
 293
 294   // Copy the temporary file to the correct filename
 295   if (!wxRenameFile(tempFile, filename))
 296   {
 297     wxCopyFile(tempFile, filename);
 298     wxRemoveFile(tempFile);
 299   }
 300
 301   wxEndBusyCursor();
 302   return TRUE;
 303 }
 304
 305 bool wxDiagram::LoadFile(const wxString& filename)
 306 {
 307   wxBeginBusyCursor();
 308
 309   wxExprDatabase database(wxExprInteger, "id");
 310   if (!database.Read(filename))
 311   {
 312     wxEndBusyCursor();
 313     return FALSE;
 314   }
 315
 316   DeleteAllShapes();
 317
 318   database.BeginFind();
 319   wxExpr *header = database.FindClauseByFunctor("diagram");
 320
 321   if (header)
 322     OnHeaderLoad(database, *header);
 323
 324   // Scan through all clauses and register the ids
 325   wxNode *node = database.First();
 326   while (node)
 327   {
 328     wxExpr *clause = (wxExpr *)node->Data();
 329     long id = -1;
 330     clause->GetAttributeValue("id", id);
 331     wxRegisterId(id);
 332     node = node->Next();
 333   }
 334
 335   ReadNodes(database);
 336   ReadContainerGeometry(database);
 337   ReadLines(database);
 338
 339   OnDatabaseLoad(database);
 340
 341   wxEndBusyCursor();
 342
 343   return TRUE;
 344 }
 345
 346 void wxDiagram::ReadNodes(wxExprDatabase& database)
 347 {
 348   // Find and create the node images
 349   database.BeginFind();
 350   wxExpr *clause = database.FindClauseByFunctor("shape");
 351   while (clause)
 352   {
 353     wxChar *type = NULL;
 354     long parentId = -1;
 355
 356     clause->AssignAttributeValue(wxT("type"), &type);
 357     clause->AssignAttributeValue(wxT("parent"), &parentId);
 358     wxClassInfo *classInfo = wxClassInfo::FindClass(type);
 359     if (classInfo)
 360     {
 361       wxShape *shape = (wxShape *)classInfo->CreateObject();
 362       OnShapeLoad(database, *shape, *clause);
 363
 364       shape->SetCanvas(GetCanvas());
 365       shape->Show(TRUE);
 366
 367       m_shapeList->Append(shape);
 368
 369       // If child of composite, link up
 370       if (parentId > -1)
 371       {
 372         wxExpr *parentExpr = database.HashFind("shape", parentId);
 373         if (parentExpr && parentExpr->GetClientData())
 374         {
 375           wxShape *parent = (wxShape *)parentExpr->GetClientData();
 376           shape->SetParent(parent);
 377           parent->GetChildren().Append(shape);
 378         }
 379       }
 380
 381       clause->SetClientData(shape);
 382     }
 383     if (type)
 384       delete[] type;
 385
 386     clause = database.FindClauseByFunctor("shape");
 387   }
 388   return;
 389 }
 390
 391 void wxDiagram::ReadLines(wxExprDatabase& database)
 392 {
 393   database.BeginFind();
 394   wxExpr *clause = database.FindClauseByFunctor("line");
 395   while (clause)
 396   {
 397     wxString type;
 398     long parentId = -1;
 399
 400     clause->GetAttributeValue("type", type);
 401     clause->GetAttributeValue("parent", parentId);
 402     wxClassInfo *classInfo = wxClassInfo::FindClass(type);
 403     if (classInfo)
 404     {
 405       wxLineShape *shape = (wxLineShape *)classInfo->CreateObject();
 406       shape->Show(TRUE);
 407
 408       OnShapeLoad(database, *shape, *clause);
 409       shape->SetCanvas(GetCanvas());
 410
 411       long image_to = -1; long image_from = -1;
 412       clause->GetAttributeValue("to", image_to);
 413       clause->GetAttributeValue("from", image_from);
 414
 415       wxExpr *image_to_expr = database.HashFind("shape", image_to);
 416
 417       if (!image_to_expr)
 418       {
 419         // Error
 420       }
 421       wxExpr *image_from_expr = database.HashFind("shape", image_from);
 422
 423       if (!image_from_expr)
 424       {
 425         // Error
 426       }
 427
 428       if (image_to_expr && image_from_expr)
 429       {
 430         wxShape *image_to_object = (wxShape *)image_to_expr->GetClientData();
 431         wxShape *image_from_object = (wxShape *)image_from_expr->GetClientData();
 432
 433         if (image_to_object && image_from_object)
 434         {
 435           image_from_object->AddLine(shape, image_to_object, shape->GetAttachmentFrom(), shape->GetAttachmentTo());
 436         }
 437       }
 438       clause->SetClientData(shape);
 439
 440       m_shapeList->Append(shape);
 441     }
 442
 443     clause = database.FindClauseByFunctor("line");
 444   }
 445 }
 446
 447 // Containers have divisions that reference adjoining divisions,
 448 // so we need a separate pass to link everything up.
 449 // Also used by Symbol Library.
 450 void wxDiagram::ReadContainerGeometry(wxExprDatabase& database)
 451 {
 452   database.BeginFind();
 453   wxExpr *clause = database.FindClauseByFunctor("shape");
 454   while (clause)
 455   {
 456     wxShape *image = (wxShape *)clause->GetClientData();
 457     if (image && image->IsKindOf(CLASSINFO(wxCompositeShape)))
 458     {
 459       wxCompositeShape *composite = (wxCompositeShape *)image;
 460       wxExpr *divisionExpr = NULL;
 461
 462       // Find the list of divisions in the composite
 463       clause->GetAttributeValue("divisions", &divisionExpr);
 464       if (divisionExpr)
 465       {
 466         int i = 0;
 467         wxExpr *idExpr = divisionExpr->Nth(i);
 468         while (idExpr)
 469         {
 470           long divisionId = idExpr->IntegerValue();
 471           wxExpr *childExpr = database.HashFind("shape", divisionId);
 472           if (childExpr && childExpr->GetClientData())
 473           {
 474             wxDivisionShape *child = (wxDivisionShape *)childExpr->GetClientData();
 475             composite->GetDivisions().Append(child);
 476
 477             // Find the adjoining shapes
 478             long leftSideId = -1;
 479             long topSideId = -1;
 480             long rightSideId = -1;
 481             long bottomSideId = -1;
 482             childExpr->GetAttributeValue("left_side", leftSideId);
 483             childExpr->GetAttributeValue("top_side", topSideId);
 484             childExpr->GetAttributeValue("right_side", rightSideId);
 485             childExpr->GetAttributeValue("bottom_side", bottomSideId);
 486             if (leftSideId > -1)
 487             {
 488               wxExpr *leftExpr = database.HashFind("shape", leftSideId);
 489               if (leftExpr && leftExpr->GetClientData())
 490               {
 491                 wxDivisionShape *leftSide = (wxDivisionShape *)leftExpr->GetClientData();
 492                 child->SetLeftSide(leftSide);
 493               }
 494             }
 495             if (topSideId > -1)
 496             {
 497               wxExpr *topExpr = database.HashFind("shape", topSideId);
 498               if (topExpr && topExpr->GetClientData())
 499               {
 500                 wxDivisionShape *topSide = (wxDivisionShape *)topExpr->GetClientData();
 501                 child->SetTopSide(topSide);
 502               }
 503             }
 504             if (rightSideId > -1)
 505             {
 506               wxExpr *rightExpr = database.HashFind("shape", rightSideId);
 507               if (rightExpr && rightExpr->GetClientData())
 508               {
 509                 wxDivisionShape *rightSide = (wxDivisionShape *)rightExpr->GetClientData();
 510                 child->SetRightSide(rightSide);
 511               }
 512             }
 513             if (bottomSideId > -1)
 514             {
 515               wxExpr *bottomExpr = database.HashFind("shape", bottomSideId);
 516               if (bottomExpr && bottomExpr->GetClientData())
 517               {
 518                 wxDivisionShape *bottomSide = (wxDivisionShape *)bottomExpr->GetClientData();
 519                 child->SetBottomSide(bottomSide);
 520               }
 521             }
 522           }
 523           i ++;
 524           idExpr = divisionExpr->Nth(i);
 525         }
 526       }
 527     }
 528
 529     clause = database.FindClauseByFunctor("shape");
 530   }
 531 }
 532
 533 // Allow for modifying file
 534 bool wxDiagram::OnDatabaseLoad(wxExprDatabase& db)
 535 {
 536   return TRUE;
 537 }
 538
 539 bool wxDiagram::OnDatabaseSave(wxExprDatabase& db)
 540 {
 541   return TRUE;
 542 }
 543
 544 bool wxDiagram::OnShapeSave(wxExprDatabase& db, wxShape& shape, wxExpr& expr)
 545 {
 546   shape.WriteAttributes(&expr);
 547   db.Append(&expr);
 548
 549   if (shape.IsKindOf(CLASSINFO(wxCompositeShape)))
 550   {
 551     wxNode *node = shape.GetChildren().First();
 552     while (node)
 553     {
 554       wxShape *childShape = (wxShape *)node->Data();
 555       wxExpr *childExpr = new wxExpr("shape");
 556       OnShapeSave(db, *childShape, *childExpr);
 557       node = node->Next();
 558     }
 559   }
 560
 561   return TRUE;
 562 }
 563
 564 bool wxDiagram::OnShapeLoad(wxExprDatabase& db, wxShape& shape, wxExpr& expr)
 565 {
 566   shape.ReadAttributes(&expr);
 567   return TRUE;
 568 }
 569
 570 bool wxDiagram::OnHeaderSave(wxExprDatabase& db, wxExpr& expr)
 571 {
 572   return TRUE;
 573 }
 574
 575 bool wxDiagram::OnHeaderLoad(wxExprDatabase& db, wxExpr& expr)
 576 {
 577   return TRUE;
 578 }
 579
 580 #endif
 581
 582 void wxDiagram::SetCanvas(wxShapeCanvas *can)
 583 {
 584   m_diagramCanvas = can;
 585 }
 586
 587 // Find a shape by its id
 588 wxShape* wxDiagram::FindShape(long id) const
 589 {
 590     wxNode* node = GetShapeList()->First();
 591     while (node)
 592     {
 593         wxShape* shape = (wxShape*) node->Data();
 594         if (shape->GetId() == id)
 595             return shape;
 596         node = node->Next();
 597     }
 598     return NULL;
 599 }
 600
 601
 602 //// Crossings classes
 603
 604 wxLineCrossings::wxLineCrossings()
 605 {
 606 }
 607
 608 wxLineCrossings::~wxLineCrossings()
 609 {
 610     ClearCrossings();
 611 }
 612
 613 void wxLineCrossings::FindCrossings(wxDiagram& diagram)
 614 {
 615     ClearCrossings();
 616     wxNode* node1 = diagram.GetShapeList()->First();
 617     while (node1)
 618     {
 619         wxShape* shape1 = (wxShape*) node1->Data();
 620         if (shape1->IsKindOf(CLASSINFO(wxLineShape)))
 621         {
 622             wxLineShape* lineShape1 = (wxLineShape*) shape1;
 623             // Iterate through the segments
 624             wxList* pts1 = lineShape1->GetLineControlPoints();
 625             int i;
 626             for (i = 0; i < (pts1->Number() - 1); i++)
 627             {
 628                 wxRealPoint* pt1_a = (wxRealPoint*) (pts1->Nth(i)->Data());
 629                 wxRealPoint* pt1_b = (wxRealPoint*) (pts1->Nth(i+1)->Data());
 630
 631                 // Now we iterate through the segments again
 632
 633                 wxNode* node2 = diagram.GetShapeList()->First();
 634                 while (node2)
 635                 {
 636                     wxShape* shape2 = (wxShape*) node2->Data();
 637
 638                     // Assume that the same line doesn't cross itself
 639                     if (shape2->IsKindOf(CLASSINFO(wxLineShape)) && (shape1 != shape2))
 640                     {
 641                         wxLineShape* lineShape2 = (wxLineShape*) shape2;
 642                         // Iterate through the segments
 643                         wxList* pts2 = lineShape2->GetLineControlPoints();
 644                         int j;
 645                         for (j = 0; j < (pts2->Number() - 1); j++)
 646                         {
 647                             wxRealPoint* pt2_a = (wxRealPoint*) (pts2->Nth(j)->Data());
 648                             wxRealPoint* pt2_b = (wxRealPoint*) (pts2->Nth(j+1)->Data());
 649
 650                             // Now let's see if these two segments cross.
 651                             double ratio1, ratio2;
 652                             oglCheckLineIntersection(pt1_a->x, pt1_a->y, pt1_b->x, pt1_b->y,
 653                                pt2_a->x, pt2_a->y, pt2_b->x, pt2_b->y,
 654                              & ratio1, & ratio2);
 655
 656                             if ((ratio1 < 1.0) && (ratio1 > -1.0))
 657                             {
 658                                 // Intersection!
 659                                 wxLineCrossing* crossing = new wxLineCrossing;
 660                                 crossing->m_intersect.x = (pt1_a->x + (pt1_b->x - pt1_a->x)*ratio1);
 661                                 crossing->m_intersect.y = (pt1_a->y + (pt1_b->y - pt1_a->y)*ratio1);
 662
 663                                 crossing->m_pt1 = * pt1_a;
 664                                 crossing->m_pt2 = * pt1_b;
 665                                 crossing->m_pt3 = * pt2_a;
 666                                 crossing->m_pt4 = * pt2_b;
 667
 668                                 crossing->m_lineShape1 = lineShape1;
 669                                 crossing->m_lineShape2 = lineShape2;
 670
 671                                 m_crossings.Append(crossing);
 672                             }
 673                         }
 674                     }
 675                     node2 = node2->Next();
 676                 }
 677             }
 678         }
 679
 680         node1 = node1->Next();
 681     }
 682 }
 683
 684 void wxLineCrossings::DrawCrossings(wxDiagram& diagram, wxDC& dc)
 685 {
 686     dc.SetBrush(*wxTRANSPARENT_BRUSH);
 687
 688     long arcWidth = 8;
 689
 690     wxNode* node = m_crossings.First();
 691     while (node)
 692     {
 693         wxLineCrossing* crossing = (wxLineCrossing*) node->Data();
 694 //        dc.DrawEllipse((long) (crossing->m_intersect.x - (arcWidth/2.0) + 0.5), (long) (crossing->m_intersect.y - (arcWidth/2.0) + 0.5),
 695 //           arcWidth, arcWidth);
 696
 697
 698         // Let's do some geometry to find the points on either end of the arc.
 699 /*
 700
 701 (x1, y1)
 702     |\
 703     | \
 704     |  \
 705     |   \
 706     |    \
 707     |    |\ c    c1
 708     |  a | \
 709          |  \
 710     |     -  x <-- centre of arc
 711  a1 |     b  |\
 712     |        | \ c2
 713     |     a2 |  \
 714     |         -  \
 715     |         b2  \
 716     |              \
 717     |_______________\ (x2, y2)
 718           b1
 719
 720 */
 721
 722         double a1 = wxMax(crossing->m_pt1.y, crossing->m_pt2.y) - wxMin(crossing->m_pt1.y, crossing->m_pt2.y) ;
 723         double b1 = wxMax(crossing->m_pt1.x, crossing->m_pt2.x) - wxMin(crossing->m_pt1.x, crossing->m_pt2.x) ;
 724         double c1 = sqrt( (a1*a1) + (b1*b1) );
 725
 726         double c = arcWidth / 2.0;
 727         double a = c * a1/c1 ;
 728         double b = c * b1/c1 ;
 729
 730         // I'm not sure this is right, since we don't know which direction we should be going in - need
 731         // to know which way the line slopes and choose the sign appropriately.
 732         double arcX1 = crossing->m_intersect.x - b;
 733         double arcY1 = crossing->m_intersect.y - a;
 734
 735         double arcX2 = crossing->m_intersect.x + b;
 736         double arcY2 = crossing->m_intersect.y + a;
 737
 738         dc.SetPen(*wxBLACK_PEN);
 739         dc.DrawArc( (long) arcX1, (long) arcY1, (long) arcX2, (long) arcY2,
 740             (long) crossing->m_intersect.x, (long) crossing->m_intersect.y);
 741
 742         dc.SetPen(*wxWHITE_PEN);
 743         dc.DrawLine( (long) arcX1, (long) arcY1, (long) arcX2, (long) arcY2 );
 744
 745         node = node->Next();
 746     }
 747 }
 748
 749 void wxLineCrossings::ClearCrossings()
 750 {
 751     wxNode* node = m_crossings.First();
 752     while (node)
 753     {
 754         wxLineCrossing* crossing = (wxLineCrossing*) node->Data();
 755         delete crossing;
 756         node = node->Next();
 757     }
 758     m_crossings.Clear();
 759 }
 760