Shamusworld >> Repos - architektonas/blob - src/drawingview.cpp

   1 // drawingview.cpp
   2 //
   3 // Part of the Architektonas Project
   4 // (C) 2011 Underground Software
   5 // See the README and GPLv3 files for licensing and warranty information
   6 //
   7 // JLH = James L. Hammons <jlhamm@acm.org>
   8 //
   9 // Who  When        What
  10 // ---  ----------  -------------------------------------------------------------
  11 // JLH  03/22/2011  Created this file
  12 //
  13
  14 // FIXED:
  15 //
  16 //
  17 // STILL TO BE DONE:
  18 //
  19 //
  20
  21 // Uncomment this for debugging...
  22 //#define DEBUG
  23 //#define DEBUGFOO            // Various tool debugging...
  24 //#define DEBUGTP                               // Toolpalette debugging...
  25
  26 #include "drawingview.h"
  27
  28 #include <stdint.h>
  29 #include "mathconstants.h"
  30
  31 #include "arc.h"
  32 #include "circle.h"
  33 #include "dimension.h"
  34 #include "line.h"
  35
  36
  37 DrawingView::DrawingView(QWidget * parent/*= NULL*/): QWidget(parent),
  38 //      scale(1.0), offsetX(-10), offsetY(-10), tool(TOOLSelect),
  39 //      ptHighlight(-1), oldPtHighlight(-1), ptNextHighlight(-1), oldPtNextHighlight(-1),
  40 //      polyFirstPoint(true)
  41         scale(1.0), offsetX(-10), offsetY(-10),
  42         document(Vector(0, 0)),
  43         gridSpacing(32.0), collided(false)
  44 {
  45         setBackgroundRole(QPalette::Base);
  46         setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
  47
  48 //      toolPalette = new ToolWindow();
  49 //      CreateCursors();
  50 //      setCursor(cur[TOOLSelect]);
  51 //      setMouseTracking(true);
  52
  53         document.Add(new Line(Vector(5, 5), Vector(50, 40), &document));
  54         document.Add(new Line(Vector(50, 40), Vector(10, 83), &document));
  55         document.Add(new Line(Vector(10, 83), Vector(17, 2), &document));
  56         document.Add(new Circle(Vector(100, 100), 36, &document));
  57         document.Add(new Circle(Vector(50, 150), 49, &document));
  58         document.Add(new Arc(Vector(300, 300), 32, PI / 4.0, PI * 1.3, &document)),
  59         document.Add(new Arc(Vector(200, 200), 60, PI / 2.0, PI * 1.5, &document));
  60         document.Add(new Dimension(Vector(5, 5), Vector(50, 40), &document));
  61 }
  62
  63 QPoint DrawingView::GetAdjustedMousePosition(QMouseEvent * event)
  64 {
  65         // This is undoing the transform, e.g. going from client coords to local coords.
  66         // In essence, the height - y is height + (y * -1), the (y * -1) term doing the
  67         // conversion of the y-axis from increasing bottom to top.
  68         return QPoint(offsetX + event->x(), offsetY + (size().height() - event->y()));
  69 }
  70
  71 QPoint DrawingView::GetAdjustedClientPosition(int x, int y)
  72 {
  73         // VOODOO ALERT (ON Y COMPONENT!!!!) (eh?)
  74         // No voodoo here, it's just grouped wrong to see it. It should be:
  75         // -offsetY + (size.height() + (y * -1.0)) <-- this is wrong, offsetY should be positive
  76         return QPoint(-offsetX + x, (size().height() - (-offsetY + y)) * +1.0);
  77 }
  78
  79 void DrawingView::paintEvent(QPaintEvent * /*event*/)
  80 {
  81         QPainter painter(this);
  82         painter.setRenderHint(QPainter::Antialiasing);
  83
  84 #if 0
  85         painter.translate(QPoint(-offsetX, size.height() - (-offsetY)));
  86         painter.scale(1.0, -1.0);
  87 #else
  88         QTransform transform;
  89 //order of operations is important! N.B.: Can't use scaling other than 1.0, it
  90 //causes lines to look strange (i.e., it scales the pen strokes too)
  91 //      transform.translate(-offsetX, size().height() - (-offsetY));
  92         transform.scale(1.0, -1.0);
  93         transform.translate(-offsetX, -size().height() - offsetY);
  94 //      transform.scale(0.25, 0.25);
  95         painter.setTransform(transform);
  96 #endif
  97         Object::SetViewportHeight(size().height());
  98
  99         // Draw coordinate axes
 100
 101         painter.setPen(QPen(Qt::blue, 1.0, Qt::DotLine));
 102         painter.drawLine(0, -16384, 0, 16384);
 103         painter.drawLine(-16384, 0, 16384, 0);
 104
 105 // Maybe we can make the grid into a background brush instead, and let Qt deal
 106 // with it???
 107         // Draw grid
 108
 109 #if 0
 110         painter.setPen(QPen(QColor(90, 90, 90), 1.0, Qt::DotLine));
 111
 112         //these two loops kill performance!
 113         for(double x=0; x<size().width(); x+=gridSpacing*10.0)
 114                 p.drawLine((int)x, -16384, (int)x, 16384);
 115
 116         for(double y=0; y<size().height(); y+=gridSpacing*10.0)
 117                 p.drawLine(-16384, (int)y, 16384, (int)y);
 118 #endif
 119
 120         painter.setPen(QPen(Qt::black, 1.0, Qt::SolidLine));
 121
 122         for(double x=0; x<size().width(); x+=gridSpacing)
 123                 for(double y=0; y<size().height(); y+=gridSpacing)
 124                         painter.drawPoint((int)x, (int)y);
 125
 126         // The top level document takes care of rendering for us...
 127         document.Draw(&painter);
 128 }
 129
 130 void DrawingView::mousePressEvent(QMouseEvent * event)
 131 {
 132         if (event->button() == Qt::LeftButton)
 133         {
 134                 QPoint pt = GetAdjustedMousePosition(event);
 135                 Vector point(pt.x(), pt.y());
 136
 137                 collided = document.Collided(point);
 138
 139                 if (collided)
 140                         update();       // Do an update if collided with at least *one* object in the document
 141         }
 142 }
 143
 144 void DrawingView::mouseMoveEvent(QMouseEvent * event)
 145 {
 146         QPoint pt = GetAdjustedMousePosition(event);
 147         Vector point(pt.x(), pt.y());
 148
 149         // Grid processing...
 150 #if 1
 151         // This looks strange, but it's really quite simple: We want a point that's
 152         // more than half-way to the next grid point to snap there while conversely
 153         // we want a point that's less than half-way to to the next grid point then
 154         // snap to the one before it. So we add half of the grid spacing to the
 155         // point, then divide by it so that we can remove the fractional part, then
 156         // multiply it back to get back to the correct answer.
 157         point += gridSpacing / 2.0;                                     // *This* adds to Z!!!
 158         point /= gridSpacing;
 159         point.x = floor(point.x);//need to fix this for negative numbers...
 160         point.y = floor(point.y);
 161         point.z = 0;                                                            // Make *sure* Z doesn't go anywhere!!!
 162         point *= gridSpacing;
 163 #endif
 164 //we should keep track of the last point here and only pass this down *if* the point
 165 //changed...
 166         document.PointerMoved(point);
 167
 168         if (document.NeedsUpdate())
 169                 update();
 170 }
 171
 172 void DrawingView::mouseReleaseEvent(QMouseEvent * event)
 173 {
 174         if (event->button() == Qt::LeftButton)
 175         {
 176                 document.PointerReleased();
 177
 178 //We need to update especially if nothing collided and the state needs to change. !!! FIX !!!
 179 //could set it up to use the document's update function (assumes that all object updates
 180 //are being reported correctly:
 181 //              if (document.NeedsUpdate())
 182 //              if (collided)
 183                         update();       // Do an update if collided with at least *one* object in the document
 184         }
 185 }
 186
 187
 188 #if 0
 189 QSize DrawingView::minimumSizeHint() const
 190 {
 191         return QSize(50, 50);
 192 }
 193
 194 QSize DrawingView::sizeHint() const
 195 {
 196         return QSize(400, 400);
 197 }
 198
 199 void DrawingView::CreateCursors(void)
 200 {
 201         int hotx[8] = {  1,  1, 11, 15,  1,  1,  1,  1 };
 202         int hoty[8] = {  1,  1, 11, 13,  1,  1,  1,  1 };
 203
 204         for(int i=0; i<8; i++)
 205         {
 206                 QString s;
 207                 s.sprintf(":/res/cursor%u.png", i+1);
 208                 QPixmap pmTmp(s);
 209                 cur[i] = QCursor(pmTmp, hotx[i], hoty[i]);
 210         }
 211 }
 212
 213 /*
 214 TODO:
 215  o  Different colors for polys on selected points
 216  o  Different colors for handles on non-selected polys
 217  o  Line of sight (dashed, dotted) for off-curve points
 218  o  Repaints for press/release of CTRL/SHIFT during point creation
 219 */
 220 void DrawingView::paintEvent(QPaintEvent * /*event*/)
 221 {
 222         QPainter p(this);
 223 //hm, causes lockup
 224 //      p.setRenderHint(QPainter::Antialiasing);
 225 //Doesn't do crap!
 226 //dc.SetBackground(*wxWHITE_BRUSH);
 227
 228 // Due to the screwiness of wxWidgets coord system, the origin is ALWAYS
 229 // the upper left corner--regardless of axis orientation, etc...
 230 //      int width, height;
 231 //      dc.GetSize(&width, &height);
 232         QSize winSize = size();
 233
 234 //      dc.SetDeviceOrigin(-offsetX, height - (-offsetY));
 235 //      dc.SetAxisOrientation(true, true);
 236         p.translate(QPoint(-offsetX, winSize.height() - (-offsetY)));
 237         p.scale(1.0, -1.0);
 238
 239 // Scrolling can be done by using OffsetViewportOrgEx
 240 // Scaling can be done by adjusting SetWindowExtEx (it's denominator of txform)
 241 // you'd use: % = ViewportExt / WindowExt
 242 // But it makes the window look like crap: fuggetuboutit.
 243 // Instead, we have to scale EVERYTHING by hand. Crap!
 244 // It's not *that* bad, but not as convenient either...
 245
 246 //      dc.SetPen(*(wxThePenList->FindOrCreatePen(wxColour(0x00, 0x00, 0xFF), 1, wxDOT)));
 247 ////    dc.DrawLine(0, 0, 10, 10);
 248         p.setPen(QPen(Qt::blue, 1.0, Qt::DotLine));
 249
 250     // Draw coordinate axes
 251
 252 //      dc.CrossHair(0, 0);
 253         p.drawLine(0, -16384, 0, 16384);
 254         p.drawLine(-16384, 0, 16384, 0);
 255
 256     // Draw points
 257
 258         for(int i=0; i<pts.GetNumPoints(); i++)
 259         {
 260                 if (i == ptHighlight)
 261                 {
 262 //                      dc.SetPen(*(wxThePenList->FindOrCreatePen(wxColour(0xFF, 0x00, 0x00), 1, wxSOLID)));
 263 ////                    SelectObject(hdc, hRedPen1);
 264                         p.setPen(QPen(Qt::red, 1.0, Qt::SolidLine));
 265
 266                         if (pts.GetOnCurve(i))
 267                         {
 268                                 DrawSquareDotN(p, pts.GetX(i), pts.GetY(i), 7);
 269                                 DrawSquareDotN(p, pts.GetX(i), pts.GetY(i), 9);
 270                         }
 271                         else
 272                         {
 273                                 DrawRoundDotN(p, pts.GetX(i), pts.GetY(i), 7);
 274                                 DrawRoundDotN(p, pts.GetX(i), pts.GetY(i), 9);
 275                         }
 276                 }
 277                 else if ((i == ptHighlight || i == ptNextHighlight) && tool == TOOLAddPt)
 278                 {
 279 //                      dc.SetPen(*(wxThePenList->FindOrCreatePen(wxColour(0x00, 0xAF, 0x00), 1, wxSOLID)));
 280 ////                    SelectObject(hdc, hGreenPen1);
 281                         p.setPen(QPen(Qt::green, 1.0, Qt::SolidLine));
 282
 283                         if (pts.GetOnCurve(i))
 284                         {
 285                                 DrawSquareDotN(p, pts.GetX(i), pts.GetY(i), 7);
 286                                 DrawSquareDotN(p, pts.GetX(i), pts.GetY(i), 9);
 287                         }
 288                         else
 289                         {
 290                                 DrawRoundDotN(p, pts.GetX(i), pts.GetY(i), 7);
 291                                 DrawRoundDotN(p, pts.GetX(i), pts.GetY(i), 9);
 292                         }
 293                 }
 294                 else
 295                 {
 296 //                      dc.SetPen(*(wxThePenList->FindOrCreatePen(wxColour(0x00, 0x00, 0x00), 1, wxSOLID)));
 297 ////                    SelectObject(hdc, hBlackPen1);
 298                         p.setPen(QPen(Qt::black, 1.0, Qt::SolidLine));
 299
 300                         if (pts.GetOnCurve(i))
 301                                 DrawSquareDot(p, pts.GetX(i), pts.GetY(i));
 302                         else
 303                                 DrawRoundDot(p, pts.GetX(i), pts.GetY(i));
 304                 }
 305
 306                 if (tool == TOOLDelPt && i == ptHighlight)
 307                 {
 308 #if 0
 309                         dc.SetPen(*(wxThePenList->FindOrCreatePen(wxColour(0xFF, 0x00, 0x00), 1, wxSOLID)));
 310 //                      SelectObject(hdc, hRedPen1);
 311 //                      MoveToEx(hdc, pts.GetX(i) - 5, pts.GetY(i) - 5, NULL);
 312 //                      LineTo(hdc, pts.GetX(i) + 5, pts.GetY(i) + 5);
 313 //                      LineTo(hdc, pts.GetX(i) - 5, pts.GetY(i) - 5);//Lameness!
 314 //                      MoveToEx(hdc, pts.GetX(i) - 5, pts.GetY(i) + 5, NULL);
 315 //                      LineTo(hdc, pts.GetX(i) + 5, pts.GetY(i) - 5);
 316 //                      LineTo(hdc, pts.GetX(i) - 5, pts.GetY(i) + 5);//More lameness!!
 317 #endif
 318                         p.setPen(QPen(Qt::red, 1.0, Qt::SolidLine));
 319                         p.drawLine(pts.GetX(i) - 5, pts.GetY(i) - 5, pts.GetX(i) + 5, pts.GetY(i) + 5);
 320                         p.drawLine(pts.GetX(i) + 5, pts.GetY(i) - 5, pts.GetX(i) - 5, pts.GetY(i) + 5);
 321                 }
 322         }
 323
 324 ////            SelectObject(hdc, hBlackPen1);
 325 //      dc.SetPen(*(wxThePenList->FindOrCreatePen(wxColour(0x00, 0x00, 0x00), 1, wxSOLID)));
 326         p.setPen(QPen(Qt::black, 1.0, Qt::SolidLine));
 327
 328         // Draw curve formed by points
 329
 330         for(int poly=0; poly<pts.GetNumPolys(); poly++)
 331         {
 332                 if (pts.GetNumPoints(poly) > 2)
 333                 {
 334                         // Initial move...
 335                         // If it's not on curve, then move to it, otherwise move to last point...
 336
 337                         int x, y;
 338
 339                         if (pts.GetOnCurve(poly, pts.GetNumPoints(poly) - 1))
 340                                 x = (int)pts.GetX(poly, pts.GetNumPoints(poly) - 1), y = (int)pts.GetY(poly, pts.GetNumPoints(poly) - 1);
 341                         else
 342                                 x = (int)pts.GetX(poly, 0), y = (int)pts.GetY(poly, 0);
 343
 344                         for(int i=0; i<pts.GetNumPoints(poly); i++)
 345                         {
 346                                 if (pts.GetOnCurve(poly, i))
 347 //                                      LineTo(hdc, pts.GetX(poly, i), pts.GetY(poly, i));
 348                                 {
 349                                         p.drawLine(x, y, pts.GetX(poly, i), pts.GetY(poly, i));
 350                                         x = (int)pts.GetX(poly, i), y = (int)pts.GetY(poly, i);
 351                                 }
 352                                 else
 353                                 {
 354                                         uint32 prev = pts.GetPrev(poly, i), next = pts.GetNext(poly, i);
 355                                         float px = pts.GetX(poly, prev), py = pts.GetY(poly, prev),
 356                                                 nx = pts.GetX(poly, next), ny = pts.GetY(poly, next);
 357
 358                                         if (!pts.GetOnCurve(poly, prev))
 359                                                 px = (px + pts.GetX(poly, i)) / 2.0f,
 360                                                 py = (py + pts.GetY(poly, i)) / 2.0f;
 361
 362                                         if (!pts.GetOnCurve(poly, next))
 363                                                 nx = (nx + pts.GetX(poly, i)) / 2.0f,
 364                                                 ny = (ny + pts.GetY(poly, i)) / 2.0f;
 365
 366                                         Bezier(p, point(px, py), point(pts.GetX(poly, i), pts.GetY(poly, i)), point(nx, ny));
 367                                         x = (int)nx, y = (int)ny;
 368
 369                                         if (pts.GetOnCurve(poly, next))
 370                                                 i++;                                    // Following point is on curve, so move past it
 371                                 }
 372                         }
 373                 }
 374         }
 375 }
 376
 377 void DrawingView::mousePressEvent(QMouseEvent * event)
 378 {
 379         if (event->button() == Qt::RightButton)
 380         {
 381                 toolPalette->move(event->globalPos());
 382                 toolPalette->setVisible(true);
 383                 setCursor(cur[TOOLSelect]);
 384                 toolPalette->prevTool = TOOLSelect;
 385         }
 386         else if (event->button() == Qt::MidButton)
 387         {
 388                 setCursor(cur[2]);                                                      // Scrolling cursor
 389         }
 390         else if (event->button() == Qt::LeftButton)
 391         {
 392                 if (tool == TOOLScroll || tool == TOOLZoom)
 393 ;//meh                  CaptureMouse();                                         // Make sure we capture the mouse when in scroll/zoom mode
 394                 else if (tool == TOOLAddPt)             // "Add Point" tool
 395                 {
 396                         if (pts.GetNumPoints() > 0)
 397                         {
 398                                 QPoint pt = GetAdjustedMousePosition(event);
 399                                 pts.InsertPoint(pts.GetNext(ptHighlight), pt.x(), pt.y(), ((event->modifiers() == Qt::ShiftModifier || event->modifiers() == Qt::ControlModifier) ? false : true));
 400                                 ptHighlight = ptNextHighlight;
 401                                 update();
 402                         }
 403                 }
 404                 else if (tool == TOOLAddPoly)   // "Add Poly" tool
 405                 {
 406 #ifdef DEBUGFOO
 407 WriteLogMsg("Adding point... # polys: %u, # points: %u", pts.GetNumPolys(), pts.GetNumPoints());
 408 #endif
 409                         if (polyFirstPoint)
 410                         {
 411                                 polyFirstPoint = false;
 412                                 pts.AddNewPolyAtEnd();
 413                         }
 414
 415                         QPoint pt = GetAdjustedMousePosition(event);
 416 //printf("GetAdjustedMousePosition = %i, %i\n", pt.x(), pt.y());
 417                         // Append a point to the end of the structure
 418                         pts += IPoint(pt.x(), pt.y(), ((event->modifiers() == Qt::ShiftModifier || event->modifiers() == Qt::ControlModifier) ? false : true));
 419                         ptHighlight = pts.GetNumPoints() - 1;
 420                         update();
 421 #ifdef DEBUGFOO
 422 WriteLogMsg(" --> [# polys: %u, # points: %u]\n", pts.GetNumPolys(), pts.GetNumPoints());
 423 #endif
 424                 }
 425                 else if (tool == TOOLSelect || tool == TOOLPolySelect)
 426                 {
 427                         if (pts.GetNumPoints() > 0)
 428                         {
 429                                 pt = GetAdjustedClientPosition(pts.GetX(ptHighlight), pts.GetY(ptHighlight));
 430 //printf("GetAdjustedClientPosition = %i, %i\n", pt.x(), pt.y());
 431 //                              WarpPointer(pt.x, pt.y);
 432                                 QCursor::setPos(mapToGlobal(pt));
 433
 434                                 if (event->modifiers() == Qt::ShiftModifier || event->modifiers() == Qt::ControlModifier)
 435                                 {
 436                                         pts.SetOnCurve(ptHighlight, !pts.GetOnCurve(ptHighlight));
 437                                         update();
 438                                 }
 439                         }
 440                 }
 441                 else if (tool == TOOLDelPt)
 442                 {
 443                         if (pts.GetNumPoints() > 0)
 444 //Or could use:
 445 //                      if (ptHighlight != -1)
 446                         {
 447 //This assumes that WM_MOUSEMOVE happens before this!
 448 //The above commented out line should take care of this contingency... !!! FIX !!!
 449                                 pts.DeletePoint(ptHighlight);
 450                                 update();
 451                         }
 452                 }
 453         }
 454
 455         event->accept();
 456 }
 457
 458 void DrawingView::mouseMoveEvent(QMouseEvent * event)
 459 {
 460         if (event->buttons() == Qt::RightButton)
 461         {
 462                 ToolType newTool = toolPalette->FindSelectedTool();
 463
 464                 if (newTool != toolPalette->prevTool)
 465                 {
 466                         toolPalette->prevTool = newTool;
 467                         toolPalette->repaint();
 468                 }
 469         }
 470         else if (event->buttons() == Qt::MidButton)
 471         {
 472                 // Calc offset from previous point
 473                 pt = event->pos();
 474                 ptOffset = QPoint(pt.x() - ptPrevious.x(), pt.y() - ptPrevious.y());
 475
 476 // Then multiply it by the scaling factor. Whee!
 477                 // This looks wacky because we're using screen coords for the offset...
 478                 // Otherwise, we would subtract both offsets!
 479                 offsetX -= ptOffset.x(), offsetY += ptOffset.y();
 480                 update();
 481                 ptPrevious = pt;
 482         }
 483         else if (event->buttons() == Qt::LeftButton)
 484         {
 485 #if 0
 486                         if (tool == TOOLScroll)
 487                         {
 488                             // Extract current point from lParam/calc offset from previous point
 489
 490                                 pt = e.GetPosition();
 491                                 ptOffset.x = pt.x - ptPrevious.x,
 492                                 ptOffset.y = pt.y - ptPrevious.y;
 493
 494                                 // NOTE: OffsetViewportOrg operates in DEVICE UNITS...
 495
 496 //Seems there's no equivalent for this in wxWidgets...!
 497 //!!! FIX !!!
 498 //                              hdc = GetDC(hWnd);
 499 //                              OffsetViewportOrgEx(hdc, ptOffset.x, ptOffset.y, NULL);
 500 //                              ReleaseDC(hWnd, hdc);
 501
 502 // this shows that it works, so the logic above must be faulty...
 503 // And it is. It should convert the coords first, then do the subtraction to figure the offset...
 504 // Above: DONE
 505 // Then multiply it by the scaling factor. Whee!
 506                                 // This looks wacky because we're using screen coords for the offset...
 507                                 // Otherwise, we would subtract both offsets!
 508                                 offsetX -= ptOffset.x, offsetY += ptOffset.y;
 509                                 Refresh();
 510                         }
 511                         else
 512 #endif
 513                         if (tool == TOOLAddPt || tool == TOOLAddPoly || tool == TOOLSelect)
 514                         {
 515                                 if (tool != TOOLAddPt || pts.GetNumPoints() > 0)//yecch.
 516                                 {
 517 //temporary, for testing. BTW, Select drag bug is here...!
 518 #if 1
 519                                         QPoint pt2 = GetAdjustedMousePosition(event);
 520                                         pts.SetXY(ptHighlight, pt2.x(), pt2.y());
 521                                         update();
 522 #endif
 523                                 }
 524                         }
 525                         else if (tool == TOOLPolySelect)
 526                         {
 527                                 if (pts.GetNumPoints() > 0)
 528                                 {
 529                                         QPoint pt2 = GetAdjustedMousePosition(event);
 530                                         // Should also set onCurve here as well, depending on keystate
 531 //Or should we?
 532                                         pts.OffsetPoly(pts.GetPoly(ptHighlight), pt2.x() - pts.GetX(ptHighlight), pt2.y() - pts.GetY(ptHighlight));
 533                                         update();
 534                                 }
 535                         }
 536         }
 537         else if (event->buttons() == Qt::NoButton)
 538         {
 539                 // Moving, not dragging...
 540                 if (tool == TOOLSelect || tool == TOOLDelPt || tool == TOOLAddPt
 541                         || tool == TOOLPolySelect)// || tool == TOOLAddPoly)
 542                 {
 543                         QPoint pt2 = GetAdjustedMousePosition(event);
 544                         double closest = 1.0e+99;
 545
 546                         for(int i=0; i<pts.GetNumPoints(); i++)
 547                         {
 548                                 double dist = ((pt2.x() - pts.GetX(i)) * (pt2.x() - pts.GetX(i)))
 549                                         + ((pt2.y() - pts.GetY(i)) * (pt2.y() - pts.GetY(i)));
 550
 551                                 if (dist < closest)
 552                                         closest = dist, ptHighlight = i;
 553                         }
 554
 555                         if (ptHighlight != oldPtHighlight)
 556                         {
 557                                 oldPtHighlight = ptHighlight;
 558                                 update();
 559                         }
 560
 561                         // What follows here looks like voodoo, but is really simple. What we do is
 562                         // check to see if the mouse point has a perpendicular intersection with any of
 563                         // the line segments. If it does, calculate the length of the perpendicular
 564                         // and choose the smallest length. If there is no perpendicular, then choose the
 565                         // length of line connecting the closer of either the first endpoint or the
 566                         // second and choose the smallest of those.
 567
 568                         // There is one bit of math that looks like voodoo to me ATM--will explain once
 569                         // I understand it better (the calculation of the length of the perpendicular).
 570
 571                         if (pts.GetNumPoints() > 1 && tool == TOOLAddPt)
 572                         {
 573                                 double smallest = 1.0e+99;
 574
 575                                 for(int i=0; i<pts.GetNumPoints(); i++)
 576                                 {
 577                                         int32 p1x = pts.GetX(i), p1y = pts.GetY(i),
 578                                                 p2x = pts.GetX(pts.GetNext(i)), p2y = pts.GetY(pts.GetNext(i));
 579
 580                                         vector ls(p2x, p2y, 0, p1x, p1y, 0), v1(pt2.x(), pt2.y(), 0, p1x, p1y, 0),
 581                                                 v2(pt2.x(), pt2.y(), 0, p2x, p2y, 0);
 582                                         double pp = ls.dot(v1) / ls.length(), dist;
 583 // Geometric interpretation:
 584 // pp is the paremeterized point on the vector ls where the perpendicular intersects ls.
 585 // If pp < 0, then the perpendicular lies beyond the 1st endpoint. If pp > length of ls,
 586 // then the perpendicular lies beyond the 2nd endpoint.
 587
 588                                         if (pp < 0.0)
 589                                                 dist = v1.length();
 590                                         else if (pp > ls.length())
 591                                                 dist = v2.length();
 592                                         else                                    // distance = ?Det?(ls, v1) / |ls|
 593                                                 dist = fabs((ls.x * v1.y - v1.x * ls.y) / ls.length());
 594
 595 //The answer to the above looks like it might be found here:
 596 //
 597 //If the segment endpoints are s and e, and the point is p, then the test for the perpendicular
 598 //intercepting the segment is equivalent to insisting that the two dot products {s-e}.{s-p} and
 599 //{e-s}.{e-p} are both non-negative.  Perpendicular distance from the point to the segment is
 600 //computed by first computing the area of the triangle the three points form, then dividing by the
 601 //length of the segment.  Distances are done just by the Pythagorean theorem.  Twice the area of the
 602 //triangle formed by three points is the determinant of the following matrix:
 603 //
 604 //sx sy 1
 605 //ex ey 1
 606 //px py 1
 607 //
 608 //By translating the start point to the origin, this can be rewritten as:
 609 //By subtracting row 1 from all rows, you get the following:
 610 //[because sx = sy = 0. you could leave out the -sx/y terms below. because we subtracted
 611 // row 1 from all rows (including row 1) row 1 turns out to be zero. duh!]
 612 //
 613 //0         0         0
 614 //(ex - sx) (ey - sy) 0
 615 //(px - sx) (py - sy) 0
 616 //
 617 //which greatly simplifies the calculation of the determinant.
 618
 619                                         if (dist < smallest)
 620                                                 smallest = dist, ptNextHighlight = pts.GetNext(i), ptHighlight = i;
 621                                 }
 622
 623                                 if (ptNextHighlight != oldPtNextHighlight)
 624                                 {
 625                                         oldPtNextHighlight = ptNextHighlight;
 626                                         update();
 627                                 }
 628                         }
 629                 }
 630
 631                 ptPrevious = event->pos();
 632         }
 633
 634         event->accept();
 635 }
 636
 637 void DrawingView::mouseReleaseEvent(QMouseEvent * event)
 638 {
 639         if (event->button() == Qt::RightButton)
 640         {
 641                 ToolType newTool = toolPalette->FindSelectedTool();
 642
 643                 // We only change the tool if a new one was actually selected. Otherwise, we do nothing.
 644                 if (newTool != TOOLNone)
 645                 {
 646                         tool = newTool;
 647
 648                         if (tool == TOOLScroll || tool == TOOLZoom || tool == TOOLAddPoly
 649                                 || tool == TOOLDelPoly)
 650                                 ptHighlight = -1;
 651
 652                         if (tool == TOOLAddPoly)
 653                                 polyFirstPoint = true;
 654                 }
 655
 656                 toolPalette->setVisible(false);
 657                 setCursor(cur[tool]);
 658                 // Just in case we changed highlighting style with the new tool...
 659                 update();
 660         }
 661         else if (event->button() == Qt::MidButton)
 662         {
 663                 setCursor(cur[tool]);                                           // Restore previous cursor
 664         }
 665         else if (event->button() == Qt::LeftButton)
 666         {
 667 //              if (tool == TOOLScroll || tool == TOOLZoom)
 668 //                      ReleaseMouse();
 669 //this is prolly too much
 670                 ((TTEdit *)qApp)->charWnd->MakePathFromPoints(&pts);
 671                 ((TTEdit *)qApp)->charWnd->update();
 672         }
 673
 674         event->accept();
 675 }
 676 #endif