Added Geometry class for common geometric tools used everywhere.

[architektonas] / src / line.cpp

diff --git a/src/line.cpp b/src/line.cpp
index 8425e62356e5062cee58b39a50da4793e0c11090..956b9bdd3c7174c16041885ed43100e758f2ff67 100644 (file)
--- a/src/line.cpp
+++ b/src/line.cpp
@@ -21,6 +21,7 @@
 #include <QtGui>
 #include "container.h"
 #include "dimension.h"
+#include "geometry.h"
 #include "mathconstants.h"
 #include "painter.h"
 
@@ -122,6 +123,10 @@ Line::~Line()
 
 /*virtual*/ bool Line::Collided(Vector point)
 {
+       // Someone told us to fuck off, so we'll fuck off. :-)
+       if (ignoreClicks)
+               return false;
+
        // We can assume this, since this is a mouse down event here.
        objectWasDragged = false;
        HitTest(point);
@@ -445,7 +450,8 @@ the horizontal line or vertical line that intersects from the current mouse posi
        Vector lineSegment = endpoint - position;
        Vector v1 = point - position;
        Vector v2 = point - endpoint;
-       double t = Vector::Parameter(position, endpoint, point);
+//     double t = Vector::Parameter(position, endpoint, point);
+       double t = Geometry::ParameterOfLineAndPoint(position, endpoint, point);
        double distance;
 
        // Geometric interpretation:
@@ -577,52 +583,55 @@ same reference number.
 
 /*virtual*/ Object * Line::Mirror(Vector p1, Vector p2)
 {
-#if 0
-       return NULL;
+#if 1
+       Point l1 = Geometry::MirrorPointAroundLine(position, p1, p2);
+       Point l2 = Geometry::MirrorPointAroundLine(endpoint, p1, p2);
+       return new Line(l1, l2);
+#else
+       Vector normal = Vector::Normal(p1, p2);
+       Vector p4 = position + normal;
 
-double Vector::Parameter(Vector v1, Vector v2, Vector p)
-{
-       // Geometric interpretation:
-       // The parameterized point on the vector lineSegment is where the normal of
-       // the lineSegment to the point intersects lineSegment. If the pp < 0, then
-       // the perpendicular lies beyond the 1st endpoint. If pp > 1, then the
-       // perpendicular lies beyond the 2nd endpoint.
-
-       Vector lineSegment = v2 - v1;
-       double magnitude = lineSegment.Magnitude();
-       Vector pointSegment = p - v1;
-       double t = lineSegment.Dot(pointSegment) / (magnitude * magnitude);
-       return t;
-}
+       // Find the intersection of the line and position + normal to the line
+       double px = (((p1.x * p2.y) - (p1.y * p2.x)) * (position.x - p4.x))
+               - ((p1.x - p2.x) * ((position.x * p4.y) - (position.y * p4.x)));
+       double py = (((p1.x * p2.y) - (p1.y * p2.x)) * (position.y - p4.y))
+               - ((p1.y - p2.y) * ((position.x * p4.y) - (position.y * p4.x)));
+       double d = ((p1.x - p2.x) * (position.y - p4.y))
+               - ((p1.y - p2.y) * (position.x - p4.x));
 
+       // px = (x1y2 - y1x2)(x3 - x4) - (x1 - x2)(x3y4 - y3x4)
+       // py = (x1y2 - y1x2)(y3 - y4) - (y1 - y2)(x3y4 - y3x4)
+       // d = (x1 - x2)(y3 - y4) - (y1 - y2)(x3 - x4) = 0 if lines are parallel
+       // Intersection is (px / d, py / d)
 
-// Return the normal to the linesegment formed by the passed in points.
-// (Not sure which is head or tail, or which hand the normal lies)
-/*static*/ Vector Vector::Normal(Vector v1, Vector v2)
-#endif
+       Vector v1(px / d, py / d);
 
-       double t1 = Vector::Parameter(p1, p2, position);
-       double t2 = Vector::Parameter(p1, p2, endpoint);
+//     Vector normal = Vector::Normal(p1, p2);
+       p4 = endpoint + normal;
 
-       Vector unit = Vector(p1, p2).Unit();
-       Vector v1 = unit * t1;
-       Vector v2 = unit * t2;
+       // Find the intersection of the line and endpoint + normal to the line
+       px = (((p1.x * p2.y) - (p1.y * p2.x)) * (endpoint.x - p4.x))
+               - ((p1.x - p2.x) * ((endpoint.x * p4.y) - (endpoint.y * p4.x)));
+       py = (((p1.x * p2.y) - (p1.y * p2.x)) * (endpoint.y - p4.y))
+               - ((p1.y - p2.y) * ((endpoint.x * p4.y) - (endpoint.y * p4.x)));
+       d = ((p1.x - p2.x) * (endpoint.y - p4.y))
+               - ((p1.y - p2.y) * (endpoint.x - p4.x));
 
-//     Vector normal = Vector::Normal(p1, p2);
-       // Get the points normal to position & endpoint to the line passed in
-       // (these are tails)
-       Vector v3 = p1 + v1;
-       Vector v4 = p1 + v2;
+       Vector v2(px / d, py / d);
 
-       // Make our mirrored vectors
-       Vector v5 = -(position - v3);
-       Vector v6 = -(endpoint - v4);
+#if 0
+       Vector v3 = position - v1;
+       Vector v4 = endpoint - v2;
 
-       // Find the points
-       Vector v7 = v3 + v5;
-       Vector v8 = v4 + v6;
+       Vector v5 = v1 + -v3;
+       Vector v6 = v2 + -v4;
+#else
+       Vector v5 = v1 + v1 - position;
+       Vector v6 = v2 + v2 - endpoint;
+#endif
 
-       return new Line(v7, v8);
+       return new Line(v5, v6);
+#endif
 }