Пример #1
0
/*
 * Find where (x1, y1) -> (x2, y2) hits one of the lines in xvec, yvec.
 * (*x3, *y3) is the point where it hits.
 *
 */
void oglFindEndForPolyline(double n, double xvec[], double yvec[],
                           double x1, double y1, double x2, double y2, double *x3, double *y3)
{
    int i;
    double lastx = xvec[0];
    double lasty = yvec[0];

    double min_ratio = 1.0;
    double line_ratio;
    double other_ratio;

    for (i = 1; i < n; i++)
    {
        oglCheckLineIntersection(x1, y1, x2, y2, lastx, lasty, xvec[i], yvec[i],
                                 &line_ratio, &other_ratio);
        lastx = xvec[i];
        lasty = yvec[i];

        if (line_ratio < min_ratio)
            min_ratio = line_ratio;
    }

    // Do last (implicit) line if last and first doubles are not identical
    if (!(xvec[0] == lastx && yvec[0] == lasty))
    {
        oglCheckLineIntersection(x1, y1, x2, y2, lastx, lasty, xvec[0], yvec[0],
                                 &line_ratio, &other_ratio);

        if (line_ratio < min_ratio)
            min_ratio = line_ratio;
    }

    *x3 = (x1 + (x2 - x1)*min_ratio);
    *y3 = (y1 + (y2 - y1)*min_ratio);

}
Пример #2
0
bool PolylineHitTest(double n, double xvec[], double yvec[],
                     double x1, double y1, double x2, double y2)
{
	bool isAHit = FALSE;
	int i;
	double lastx = xvec[0];
	double lasty = yvec[0];

	double min_ratio = 1.0;
	double line_ratio;
	double other_ratio;

	for (i = 1; i < n; i++)
	{
		oglCheckLineIntersection(x1, y1, x2, y2, lastx, lasty, xvec[i], yvec[i],
		                         &line_ratio, &other_ratio);
		if (line_ratio != 1.0)
			isAHit = TRUE;
		lastx = xvec[i];
		lasty = yvec[i];

		if (line_ratio < min_ratio)
			min_ratio = line_ratio;
	}

	// Do last (implicit) line if last and first doubles are not identical
	if (!(xvec[0] == lastx && yvec[0] == lasty))
	{
		oglCheckLineIntersection(x1, y1, x2, y2, lastx, lasty, xvec[0], yvec[0],
		                         &line_ratio, &other_ratio);
		if (line_ratio != 1.0)
			isAHit = TRUE;

	}
	return isAHit;
}
Пример #3
0
void wxLineCrossings::FindCrossings(wxDiagram& diagram)
{
    ClearCrossings();
    wxNode* node1 = diagram.GetShapeList()->GetFirst();
    while (node1)
    {
        wxShape* shape1 = (wxShape*) node1->GetData();
        if (shape1->IsKindOf(CLASSINFO(wxLineShape)))
        {
            wxLineShape* lineShape1 = (wxLineShape*) shape1;
            // Iterate through the segments
            wxList* pts1 = lineShape1->GetLineControlPoints();
            size_t i;
            for (i = 0; i < (pts1->GetCount() - 1); i++)
            {
                wxRealPoint* pt1_a = (wxRealPoint*) (pts1->Item(i)->GetData());
                wxRealPoint* pt1_b = (wxRealPoint*) (pts1->Item(i+1)->GetData());

                // Now we iterate through the segments again

                wxNode* node2 = diagram.GetShapeList()->GetFirst();
                while (node2)
                {
                    wxShape* shape2 = (wxShape*) node2->GetData();

                    // Assume that the same line doesn't cross itself
                    if (shape2->IsKindOf(CLASSINFO(wxLineShape)) && (shape1 != shape2))
                    {
                        wxLineShape* lineShape2 = (wxLineShape*) shape2;
                        // Iterate through the segments
                        wxList* pts2 = lineShape2->GetLineControlPoints();
                        int j;
                        for (j = 0; j < (int) (pts2->GetCount() - 1); j++)
                        {
                            wxRealPoint* pt2_a = (wxRealPoint*) (pts2->Item(j)->GetData());
                            wxRealPoint* pt2_b = (wxRealPoint*) (pts2->Item(j+1)->GetData());

                            // Now let's see if these two segments cross.
                            double ratio1, ratio2;
                            oglCheckLineIntersection(pt1_a->x, pt1_a->y, pt1_b->x, pt1_b->y,
                               pt2_a->x, pt2_a->y, pt2_b->x, pt2_b->y,
                             & ratio1, & ratio2);

                            if ((ratio1 < 1.0) && (ratio1 > -1.0))
                            {
                                // Intersection!
                                wxLineCrossing* crossing = new wxLineCrossing;
                                crossing->m_intersect.x = (pt1_a->x + (pt1_b->x - pt1_a->x)*ratio1);
                                crossing->m_intersect.y = (pt1_a->y + (pt1_b->y - pt1_a->y)*ratio1);

                                crossing->m_pt1 = * pt1_a;
                                crossing->m_pt2 = * pt1_b;
                                crossing->m_pt3 = * pt2_a;
                                crossing->m_pt4 = * pt2_b;

                                crossing->m_lineShape1 = lineShape1;
                                crossing->m_lineShape2 = lineShape2;

                                m_crossings.Append(crossing);
                            }
                        }
                    }
                    node2 = node2->GetNext();
                }
            }
        }

        node1 = node1->GetNext();
    }
}