1 // line.cpp: Line object
3 // Part of the Architektonas Project
4 // (C) 2011 Underground Software
5 // See the README and GPLv3 files for licensing and warranty information
7 // JLH = James Hammons <jlhamm@acm.org>
10 // --- ---------- ------------------------------------------------------------
11 // JLH 03/22/2011 Created this file
12 // JLH 04/11/2011 Fixed attached dimensions to stay at correct length when
13 // "Fixed Length" button is down
14 // JLH 04/27/2011 Fixed attached dimension to stay a correct length when
15 // "Fixed Length" button is *not* down ;-)
16 // JLH 05/29/2011 Added (some) mouseover hints
22 #include "container.h"
23 #include "dimension.h"
25 #include "mathconstants.h"
29 Line::Line(Vector p1, Vector p2, Object * p/*= NULL*/): Object(p1, p),
30 /*type(OTLine),*/ endpoint(p2),
31 draggingLine(false), draggingHandle1(false), draggingHandle2(false), //needUpdate(false),
32 length(Vector::Magnitude(p2, p1)), angle(Vector(endpoint - position).Unit()),
33 hitPoint1(false), hitPoint2(false), hitLine(false)
41 // Taking care of connections should be done by the Container, as we don't know
42 // anything about any other object connected to this one.
44 // If there are any attached Dimensions, we must set the attachment points
45 // to NULL since they will no longer be valid.
46 if (attachedDimension)
48 attachedDimension->SetPoint1(NULL);
49 attachedDimension->SetPoint2(NULL);
51 // IT WOULD BE NICE to have any object points attached to this line automagically
52 // connect to this dimension object at this point, instead of just becoming
58 /*virtual*/ void Line::Draw(Painter * painter)
60 painter->SetPen(QPen(Qt::red, 2.0, Qt::DotLine));
62 if ((state == OSSelected) || ((state == OSInactive) && hitPoint1))
63 painter->DrawHandle(position);
65 if ((state == OSSelected) || ((state == OSInactive) && hitPoint2))
66 painter->DrawHandle(endpoint);
68 if ((state == OSInactive) && !hitLine)
69 painter->SetPen(QPen(Qt::black, 1.0, Qt::SolidLine));
71 if (Object::fixedLength && (draggingHandle1 || draggingHandle2))
73 Vector point1 = (draggingHandle1 ? endpoint : position);
74 Vector point2 = (draggingHandle1 ? position : endpoint);
76 Vector current(point2 - point1);
77 Vector v = current.Unit() * length;
78 Vector v2 = point1 + v;
79 painter->DrawLine(point1, v2);
81 if (current.Magnitude() > length)
83 painter->SetPen(QPen(QColor(128, 0, 0), 1.0, Qt::DashLine));
84 painter->DrawLine(v2, point2);
88 painter->DrawLine(position, endpoint);
90 // If we're dragging an endpoint, draw an information panel showing both
91 // the length and angle being set.
92 if (draggingHandle1 || draggingHandle2)
94 double absAngle = (Vector(endpoint - position).Angle()) * RADIANS_TO_DEGREES;
95 double absLength = Vector(position - endpoint).Magnitude();
97 QString text = QObject::tr("Length: %1 in.\n") + QChar(0x2221) + QObject::tr(": %2");
98 text = text.arg(absLength).arg(absAngle);
100 QPen pen = QPen(QColor(0x00, 0xFF, 0x00), 1.0, Qt::SolidLine);
101 painter->SetPen(pen);
102 painter->SetBrush(QBrush(QColor(0x40, 0xFF, 0x40, 0x9F)));
103 QRectF textRect(10.0, 10.0, 270.0, 70.0); // x, y, w, h (in Qt coords)
104 painter->DrawRoundedRect(textRect, 7.0, 7.0);
106 textRect.setLeft(textRect.left() + 14);
107 painter->SetFont(*Object::font);
108 pen = QPen(QColor(0x00, 0x5F, 0xDF));
109 painter->SetPen(pen);
110 painter->DrawText(textRect, Qt::AlignVCenter, text);
112 painter->DrawInformativeText(text);
117 /*virtual*/ Vector Line::Center(void)
119 // Technically, this is the midpoint but who are we to quibble? :-)
120 Vector v((position.x - endpoint.x) / 2.0, (position.y - endpoint.y) / 2.0);
124 /*virtual*/ bool Line::Collided(Vector point)
127 what we can do here is set ignoreClicks to true to keep other objects that are
128 selected from deselecting themselves. Will that fuck up something else? Not sure
131 // Someone told us to fuck off, so we'll fuck off. :-)
135 // We can assume this, since this is a mouse down event here.
136 objectWasDragged = false;
139 // Now that we've done our hit testing on the non-snapped point, snap it if
142 point = SnapPointToGrid(point);
144 // this is shite. this should be checked for in the Container, not here!
145 #warning "!!! This should be checked for in Container, not here !!!"
146 // If we're part of a non-top-level container, send this signal to it
147 if (parent->type == OTContainer && !((Container *)parent)->isTopLevelContainer
148 && (hitLine || hitPoint1 || hitPoint2))
150 parent->state = OSSelected;
155 There's a small problem here with the implementation: You can have a dimension tied
156 to only one point while at the same time you can have a dimension sitting on this line.
157 Since there's only *one* dimPoint for each point, this can be problematic...
159 We solve this by allowing only *one* Dimension object to be attached to the Line,
160 Arc, etc. and by giving the Dimension object a pointer to our endpoints.
162 Problem still arises when we delete this object; The attached Dimension object will
163 then have bad pointers! What it *should* do is delete the object if and only if this
164 line is not attached to any other object. If it is, then one of those attachment
165 points should be sent to the dimension object (done for position & endpoint).
167 NOTE: The STL vector<T> *does not* take ownership of pointers, therefore is suitable
170 Also: It would be nice to have a preview of the dimension being drawn, with a modifier
171 key to make it draw/show on the other side...
173 TODO: Make Dimension preview with modifier keys for showing on other side
177 N.B.: This no longer works, as the DrawDimension object takes precedence over this code.
178 THIS DOES NOTHING ANYMORE!!!
182 // Is the dimension tool active? Let's use it:
185 // User clicked on the line itself (endpoint checks should preceed this one):
186 // (Priorities are taken care of in HitTest()...)
190 if (attachedDimension == NULL)
192 // How to get this object into the top level container???
194 The real question is do we care. I think so, because if this isn't in the top
195 level container, it won't get drawn...
196 But we can fix that by making this object call any attached object's (like
197 a dimension only) Draw() function... :-/
199 attachedDimension = new Dimension(&position, &endpoint, DTLinear, this);
202 parent->Add(attachedDimension);
206 // If there's one already there, tell it to flip sides...
207 attachedDimension->FlipSides();
210 // New approach here: We look for connected objects.
211 Object * attachedDimension = FindAttachedDimension();
213 if (attachedDimension)
215 // If there's an attached Dimension, tell it to switch sides...
216 ((Dimension *)attachedDimension)->FlipSides();
220 // Otherwise, we make a new one and attach it here.
221 attachedDimension = new Dimension(Connection(this, 0), Connection(this, 1.0), DTLinear, this);
222 connected.push_back(Connection(attachedDimension, 0));
223 connected.push_back(Connection(attachedDimension, 1.0));
226 parent->Add(attachedDimension);
235 if (state == OSInactive)
237 //How to translate this into pixels from Document space???
238 //Maybe we need to pass a scaling factor in here from the caller? That would
239 //make sense, as the caller knows about the zoom factor and all that good kinda
241 //I think what's needed is an Object class variable/method that can be changed
242 //by the TLC and called in derived classes to properly scale the location to
243 //the current zoom level. That *should* work.
245 // ALSO: Need to code a global (read: Object class) variable that tells use
246 // whether a modifier key was pressed in addition to the mouse click, so
247 // we can do stuff like, say, hold down CTRL and be able to do multiple
248 // selecting of objects (in that case, we would keep the Object state
255 draggingHandle1 = true;
263 draggingHandle2 = true;
275 else if (state == OSSelected)
280 // state = OSInactive;
284 // Toggle selected state if CTRL held
285 if (qApp->keyboardModifiers() == Qt::ControlModifier)
292 // If CTRL is held, then we bypass the "turn off" code. Still didn't hit
293 // *this* object though. :-)
294 if (qApp->keyboardModifiers() == Qt::ControlModifier)
297 // If we got here, we clicked on nothing, so set the object to inactive.
298 // (Once we can read key modifiers, we can override this to allow multiple selection.)
304 /*virtual*/ void Line::PointerMoved(Vector point)
306 if (selectionInProgress)
308 // Check for whether or not the rect contains this line
310 if (selection.normalized().contains(Extents()))
312 // if (selection.normalized().contains(position.x, position.y)
313 // && selection.normalized().contains(endpoint.x, endpoint.y))
314 if (selection.contains(position.x, position.y)
315 && selection.contains(endpoint.x, endpoint.y))
324 // Hit test tells us what we hit (if anything) through boolean variables. (It
325 // also tells us whether or not the state changed. --not any more)
328 needUpdate = HitStateChanged();
330 objectWasDragged = (draggingLine | draggingHandle1 | draggingHandle2);
332 if (objectWasDragged)
334 Vector delta = point - oldPoint;
336 if (draggingHandle1 || draggingLine)
339 if (draggingHandle2 || draggingLine)
345 //doesn't work QMainWindow::statusBar()->setText("You are manipulating a line");
347 // Tell connected objects to move themselves...
350 std::vector<Connection>::iterator i;
352 for(i=connected.begin(); i!=connected.end(); i++)
354 if ((*i).object->type == OTLine)
355 ((Line *)((*i).object))->MovePointAtParameter((*i).t, delta);
361 We can't count on any coupling between the dimension object and us, so how do we do this???
362 Also, there may be more than one Dimension object connected to a single endpoint!
365 - Keep track of the state of the connected dimension
366 - Pass the Dimension the point that's being changed and the delta
369 - Pass the point in a notification function (how?)
370 - Pass the point as a reference to the class instance object (&endpoint). This
371 way, the line doesn't have to care about keeping track of Dimensions
372 connected to it. But still have to care about other connected entities
373 (other Lines, Circles, Arcs, Splines, Texts, etc). I think I'd be OK with
374 this. Since the Dimension has a pointer to our object, all we have to do is
375 update our coordinates and the Dimension object will adjust itself on the
376 next repaint. Problem solved, and we don't have to know anything about how
377 many Dimensions are connected to us, or where! \o/
378 The question then becomes, how do we do this kind of coupling???
380 We need to know about connected entities so that we can have them either move
381 in expected ways or constrain the movement of this Line object. This is how we
382 will be a cut above all other CAD software currently out there: the GUI will
383 try to do the right thing, most of the time. :-)
387 // should only do this if "Fixed Length" is set... !!! FIX !!! [DONE]
388 Vector point1 = (draggingHandle1 ? endpoint : position);
389 Vector point2 = (draggingHandle1 ? position : endpoint);
391 if (Object::fixedAngle)
393 // Here we calculate the component of the current vector along the fixed angle.
394 // A_compB = (A . Bu) * Bu
395 double magnitudeAlongB = Vector::Dot(Vector(point2 - point1), angle);
397 Actually, this isn't quite right. What we want to do is look for the intersection along either
398 the horizontal line or vertical line that intersects from the current mouse position.
402 position = endpoint + (angle * magnitudeAlongB);
405 endpoint = position + (angle * magnitudeAlongB);
410 //If we tell the dimension to flip sides, this is no longer a valid
411 //assumption. !!! FIX !!!
412 //Ideally, we should just send the point that's changing to the Dimension object
413 //and have it figure out which point needs to move... Or is it???
414 // Ideally, we shouldn't have to fuck around with this shit. We need to fix the rendering code
415 // so that we don't have to wait until the dragging is done to correct the position of the
416 // point in question, but we'd need another variable tho.
419 dimPoint1->SetPoint1(draggingHandle1 ? v2 : position);
422 dimPoint2->SetPoint2(draggingHandle2 ? v2 : endpoint);
428 /*virtual*/ void Line::PointerReleased(void)
430 if (draggingHandle1 || draggingHandle2)
432 // Set the length (in case the global state was set to fixed (or not))
433 if (Object::fixedLength)
435 if (draggingHandle1) // startpoint
437 Vector v = Vector(position - endpoint).Unit() * length;
438 position = endpoint + v;
442 Vector v = Vector(endpoint - position).Unit() * length;
443 endpoint = position + v;
448 // Otherwise, we calculate the new length, just in case on the next
449 // move it turns out to have a fixed length. :-)
450 length = Vector(endpoint - position).Magnitude();
453 if (!Object::fixedAngle)
455 // Calculate the new angle, just in case on the next move it turns
456 // out to be fixed. :-)
457 angle = Vector(endpoint - position).Unit();
461 draggingLine = false;
462 draggingHandle1 = false;
463 draggingHandle2 = false;
465 if (objectWasDragged)
470 /*virtual*/ bool Line::HitTest(Point point)
472 hitPoint1 = hitPoint2 = hitLine = false;
473 Vector lineSegment = endpoint - position;
474 Vector v1 = point - position;
475 Vector v2 = point - endpoint;
476 double t = Geometry::ParameterOfLineAndPoint(position, endpoint, point);
479 // Geometric interpretation of "distance = ?Det?(ls, v1) / |ls|":
480 // If the segment endpoints are s and e, and the point is p, then the test
481 // for the perpendicular intercepting the segment is equivalent to insisting
482 // that the two dot products {s-e}.{s-p} and {e-s}.{e-p} are both non-negative.
483 // Perpendicular distance from the point to the segment is computed by first
484 // computing the area of the triangle the three points form, then dividing by
485 // the length of the segment. Distances are done just by the Pythagorean
486 // theorem. Twice the area of the triangle formed by three points is the
487 // determinant of the following matrix:
489 // sx sy 1 0 0 1 0 0 0
490 // ex ey 1 ==> ex ey 1 ==> ex ey 0
491 // px py 1 px py 1 px py 0
493 // By translating the start point to the origin, and subtracting row 1 from
494 // all other rows, we end up with the matrix on the right which greatly
495 // simplifies the calculation of the determinant.
498 distance = v1.Magnitude();
500 distance = v2.Magnitude();
502 // distance = ?Det?(ls, v1) / |ls|
503 distance = fabs((lineSegment.x * v1.y - v1.x * lineSegment.y)
504 / lineSegment.Magnitude());
506 if ((v1.Magnitude() * Painter::zoom) < 8.0)
508 else if ((v2.Magnitude() * Painter::zoom) < 8.0)
510 else if ((distance * Painter::zoom) < 5.0)
513 return (hitPoint1 || hitPoint2 || hitLine ? true : false);
517 // Check to see if the point passed in coincides with any we have. If so, return a
518 // pointer to it; otherwise, return NULL.
519 /*virtual*/ Vector * Line::GetPointAt(Vector v)
523 else if (v == endpoint)
530 /*virtual*/ void Line::Enumerate(FILE * file)
532 fprintf(file, "LINE %i (%lf,%lf) (%lf,%lf)\n", layer, position.x, position.y, endpoint.x, endpoint.y);
536 /*virtual*/ Object * Line::Copy(void)
538 #warning "!!! This doesn't take care of attached Dimensions !!!"
540 This is a real problem. While having a pointer in the Dimension to this line's points
541 is fast & easy, it creates a huge problem when trying to replicate an object like this.
543 Maybe a way to fix that then, is to have reference numbers instead of pointers. That
544 way, if you copy them, ... you might still have problems. Because you can't be sure if
545 a copy will be persistant or not, you then *definitely* do not want them to have the
546 same reference number.
548 return new Line(position, endpoint, parent);
552 /*virtual*/ Vector Line::GetPointAtParameter(double parameter)
554 // Is there any real reason to clamp this to the endpoints?
555 // (hey, whaddya know? this was masking a bug!)
559 else if (parameter >= 1.0)
563 // The parameter is a percentage of the length of the vector, so all we
564 // have to do is scale the vector by it to find the point.
565 return position + (Vector(position, endpoint) * parameter);
569 /*virtual*/ void Line::MovePointAtParameter(double parameter, Vector v)
573 else if (parameter == 1.0)
576 {} // Not sure how to handle this case :-P
580 /*virtual*/ QRectF Line::Extents(void)
582 QRectF rect(QPointF(position.x, position.y), QPointF(endpoint.x, endpoint.y));
583 return rect.normalized();
587 /*virtual*/ void Line::Translate(Vector amount)
594 /*virtual*/ void Line::Rotate(Point point, double angle)
596 Point l1 = Geometry::RotatePointAroundPoint(position, point, angle);
597 Point l2 = Geometry::RotatePointAroundPoint(endpoint, point, angle);
603 /*virtual*/ void Line::Scale(Point point, double amount)
608 /*virtual*/ void Line::Mirror(Point p1, Point p2)
610 Point l1 = Geometry::MirrorPointAroundLine(position, p1, p2);
611 Point l2 = Geometry::MirrorPointAroundLine(endpoint, p1, p2);
617 /*virtual*/ void Line::Save(void)
620 oldEndpoint = endpoint;
624 /*virtual*/ void Line::Restore(void)
627 endpoint = oldEndpoint;
631 void Line::SetDimensionOnLine(Dimension * dimension/*= NULL*/)
633 // If they don't pass one in, create it for the caller.
634 if (dimension == NULL)
636 //printf("Line::SetDimensionOnLine(): Creating new dimension...\n");
637 // dimension = new Dimension(position, endpoint, DTLinear, this);
638 dimension = new Dimension(Connection(this, 0), Connection(this, 1.0), DTLinear, this);
642 //printf("Line::SetDimensionOnLine(): Adding to parent...\n");
643 parent->Add(dimension);
648 dimension->Connect(this, 0);
649 dimension->Connect(this, 1.0);
652 // Make sure the Dimension is connected to us...
653 Connect(dimension, 0);
654 Connect(dimension, 1.0);
658 Object * Line::FindAttachedDimension(void)
660 // Is there anything connected to this line? If not, return NULL
661 if (connected.size() < 2)
664 // Otherwise, we have to search our objects to see if there's a likely
665 // candidate. In this case, we're looking for a pointer to the same object
666 // with a parameter of 0 and 1 respectively. This is O((n^2)/2).
667 for(uint i=0; i<connected.size(); i++)
669 for(uint j=i+1; j<connected.size(); j++)
671 //printf("Line: connected[i]=%X, connected[j]=%X, connected[i].t=%lf, connected[j].t=%lf\n", connected[i].object, connected[j].object, connected[i].t, connected[j].t);
672 if ((connected[i].object == connected[j].object)
673 && ((connected[i].t == 0 && connected[j].t == 1.0)
674 || (connected[i].t == 1.0 && connected[j].t == 0)))
675 return connected[i].object;
679 // Didn't find anything, so return NULL
684 void Line::SaveHitState(void)
686 oldHitPoint1 = hitPoint1;
687 oldHitPoint2 = hitPoint2;
688 oldHitLine = hitLine;
692 bool Line::HitStateChanged(void)
694 if ((hitPoint1 != oldHitPoint1) || (hitPoint2 != oldHitPoint2) || (hitLine != oldHitLine))
702 Intersection of two lines:
704 Find where the lines with equations r = i + j + t (3i - j) and r = -i + s (j) intersect.
706 When they intersect, we can set the equations equal to one another:
708 i + j + t (3i - j) = -i + s (j)
710 Equating coefficients:
711 1 + 3t = -1 and 1 - t = s
712 So t = -2/3 and s = 5/3
714 The position vector of the intersection point is therefore given by putting t = -2/3 or s = 5/3 into one of the above equations. This gives -i +5j/3 .
717 so, let's say we have two lines, l1 and l2. Points are v0(p0x, p0y), v1(p1x, p1y) for l1
718 and v2(p2x, p2y), v3(p3x, p3y) for l2.
720 d1 = v1 - v0, d2 = v3 - v2
722 Our parametric equations for the line then are:
727 Set r1 = r2, thus we have:
729 v0 + t(d1) = v2 + s(d2)
731 Taking coefficients, we have:
733 p0x + t(d1x) = p2x + s(d2x)
734 p0y + t(d1y) = p2y + s(d2y)
738 t(d1x) - s(d2x) = p2x - p0x
739 t(d1y) - s(d2y) = p2y - p0y
741 Determinant D is ad - bc where the matrix looks like:
746 so D = (d1x)(d2y) - (d2x)(d1y)
747 if D = 0, the lines are parallel.
748 Dx = (p2x - p0x)(d2y) - (d2x)(p2y - p0y)
749 Dy = (d1x)(p2y - p0y) - (p2x - p0x)(d1y)
752 We only need to calculate t, as we can then multiply it by d1 to get the intersection point.
754 ---------------------------------------------------------------------------------------------------
756 The first and most preferred method for intersection calculation is the perp-product calculation. There are two vectors, v1 and v2. Create a third vector vector between the starting points of these vectors, and calculate the perp product of v2 and the two other vectors. These two scalars have to be divided to get the mulitplication ratio of v1 to reach intersection point. So:
762 Perp product is equal with dot product of normal of first vector and the second vector, so we need normals:
769 dp1 = n3 . v2 = -by3 * bx2 + bx3 * by2;
770 dp2 = n1 . v2 = -by1 * bx2 + bx1 * by2;
773 crossing vector = v1 * ratio;
777 -----------------------------------
779 So... to code this, let's say we have two Lines: l1 & l2.
781 Vector v1 = l1.endpoint - l1.position;
782 Vector v2 = l2.endpoint - l2.position;
785 Vector normal1(-v1.y, v1.x);
786 Vector normal3(-v3.y, v3.x);
788 double dotProduct1 = v2.Dot(normal1);
789 double dotProduct2 = v2.Dot(normal3);
791 if (dotProduct2 == 0)
792 return ParallelLines;
795 // I think we'd still have to add the intersection to the position point to get the intersection...
796 Point intersection = v1 * (dotProduct1 / dotProduct2);