--- /dev/null
+#include "geometry.h"
+
+#include "misc.h"
+#include <math.h>
+
+#include <QString>
+
+#include <iostream>
+using namespace std;
+
+QRectF addBBox(QRectF r1, QRectF r2)
+{
+ // Find smallest QRectF containing given rectangles
+
+ QRectF n;
+ // Set left border
+ if (r1.left() <= r2.left())
+ n.setLeft(r1.left());
+ else
+ n.setLeft(r2.left());
+
+ // Set top border
+ if (r1.top() <= r2.top())
+ n.setTop(r1.top());
+ else
+ n.setTop(r2.top());
+
+ // Set right border
+ if (r1.right() <= r2.right())
+ n.setRight(r2.right());
+ else
+ n.setRight(r1.right());
+
+ // Set bottom
+ if (r1.bottom() <= r2.bottom())
+ n.setBottom(r2.bottom());
+ else
+ n.setBottom(r1.bottom());
+ return n;
+}
+
+QSize addBBoxSize(QSize s1, QSize s2)
+{
+ // Find the minimimum smallest QSize which could include 2 given sizes
+
+ QSize s = s1;
+ if (s1.width() <= s2.width())
+ s.setWidth(s2.width());
+ if (s1.height() <= s2.height())
+ s.setHeight(s2.height());
+ return s;
+}
+
+bool isInBox(const QPointF &p, const QRectF &box)
+{
+ if (p.x() >= box.left() && p.x() <= box.right() && p.y() <= box.bottom() &&
+ p.y() >= box.top())
+ return true;
+ return false;
+}
+
+qreal Geometry::distance(const QPointF &p, const QPointF &q)
+{
+ return sqrt(p.x() * q.x() + p.y() * q.y());
+}
+
+Vector::Vector() : QPointF() {}
+
+Vector::Vector(const QPointF &p) : QPointF(p) {}
+
+Vector::Vector(qreal x, qreal y) : QPointF(x, y) {}
+
+Vector::~Vector() {}
+
+//! Check if length is 0
+bool Vector::isNull()
+{
+ if (x() == 0 && y() == 0)
+ return true;
+ return false;
+}
+
+//! Normalize vector
+void Vector::normalize()
+{
+ if (isNull())
+ return;
+ qreal l = sqrt(x() * x() + y() * y());
+ setX(x() / l);
+ setY(y() / l);
+}
+
+//! Dot product of two vectors
+qreal Vector::dotProduct(const QPointF &b) { return x() * b.x() + y() * b.y(); }
+
+void Vector::scale(const qreal &f)
+{
+ setX(x() * f);
+ setY(y() * f);
+}
+
+void Vector::invert()
+{
+ setX(-x());
+ setY(-y());
+}
+
+QPointF Vector::toQPointF() { return QPointF(x(), y()); }
+
+/*! Calculate the projection of a polygon on an axis
+ and returns it as a [min, max] interval */
+ConvexPolygon::ConvexPolygon() {}
+
+ConvexPolygon::ConvexPolygon(QPolygonF p) : QPolygonF(p) {}
+
+ConvexPolygon::~ConvexPolygon() {}
+
+void ConvexPolygon::calcCentroid()
+{
+ // Calculate area and centroid
+ // http://en.wikipedia.org/wiki/Centroid
+ qreal cx, cy, p;
+ cx = cy = 0;
+ _area = 0;
+
+ append(at(0));
+ for (int i = 0; i < size() - 1; i++) {
+ p = at(i).x() * at(i + 1).y() - at(i + 1).x() * at(i).y();
+ _area += p;
+ cx += (at(i).x() + at(i + 1).x()) * p;
+ cy += (at(i).y() + at(i + 1).y()) * p;
+ }
+ pop_back();
+ // area is negative if vertices ordered counterclockwise
+ // (in mirrored graphicsview!)
+ _area = _area / 2;
+ p = _area * 6;
+ _centroid.setX(cx / p);
+ _centroid.setY(cy / p);
+}
+
+QPointF ConvexPolygon::centroid() const { return _centroid; }
+
+qreal ConvexPolygon::weight() const { return _area; }
+
+std::string ConvexPolygon::toStdString()
+{
+ QString s("(");
+ for (int i = 0; i < size(); ++i) {
+ s += QString("(%1,%2)").arg(at(i).x()).arg(at(i).y());
+ if (i < size() - 1)
+ s += ",";
+ }
+ s += ")";
+ return s.toStdString();
+}
+
+Vector ConvexPolygon::at(const int &i) const
+{
+ return Vector(QPolygonF::at(i).x(), QPolygonF::at(i).y());
+}
+
+void ConvexPolygon::translate(const Vector &offset)
+{
+ translate(offset.x(), offset.y());
+}
+
+void ConvexPolygon::translate(qreal dx, qreal dy)
+{
+ QPolygonF::translate(dx, dy);
+ _centroid = _centroid + QPointF(dx, dy);
+}
+
+void projectPolygon(Vector axis, ConvexPolygon polygon, qreal &min, qreal &max)
+{
+ // To project a point on an axis use the dot product
+
+ // qDebug() << "Projecting on "<< axis;
+ qreal d = axis.dotProduct(polygon.at(0));
+ min = d;
+ max = d;
+ for (int i = 0; i < polygon.size(); i++) {
+ d = polygon.at(i).dotProduct(axis);
+ if (d < min)
+ min = d;
+ else if (d > max)
+ max = d;
+ // qDebug() << "p="<<polygon.at(i)<<" d="<<d<<" (min,
+ //max)=("<<min<<","<<max<<")";
+ }
+}
+
+// Calculate the signed distance between [minA, maxA] and [minB, maxB]
+// The distance will be negative if the intervals overlap
+
+qreal intervalDistance(qreal minA, qreal maxA, qreal minB, qreal maxB)
+{
+ if (minA < minB) {
+ return minB - maxA;
+ }
+ else {
+ return minA - maxB;
+ }
+}
+
+/*!
+ Check if polygon A is going to collide with polygon B.
+ The last parameter is the *relative* velocity
+ of the polygons (i.e. velocityA - velocityB)
+*/
+
+PolygonCollisionResult polygonCollision(ConvexPolygon polygonA,
+ ConvexPolygon polygonB, Vector velocity)
+{
+ PolygonCollisionResult result;
+ result.intersect = true;
+ result.willIntersect = true;
+
+ int edgeCountA = polygonA.size();
+ int edgeCountB = polygonB.size();
+ qreal minIntervalDistance = 1000000000;
+ QPointF translationAxis;
+ QPointF edge;
+
+ /*
+ qDebug() << "A: ";
+ for (int k=0; k<edgeCountA;k++)
+ qDebug() <<polygonA.at(k);
+ qDebug() << "B: ";
+ for (int k=0; k<edgeCountB;k++)
+ qDebug() <<polygonB.at(k);
+ qDebug() ;
+ */
+
+ // Loop through all the edges of both polygons
+ for (int i = 0; i < edgeCountA + edgeCountB; i++) {
+ if (i < edgeCountA) {
+ // Loop through polygon A
+ if (i < edgeCountA - 1)
+ edge = QPointF(polygonA.at(i + 1).x() - polygonA.at(i).x(),
+ polygonA.at(i + 1).y() - polygonA.at(i).y());
+ else
+ edge = QPointF(polygonA.at(0).x() - polygonA.at(i).x(),
+ polygonA.at(0).y() - polygonA.at(i).y());
+ }
+ else {
+ // Loop through polygon B
+ if (i < edgeCountA + edgeCountB - 1)
+ edge = QPointF(polygonB.at(i - edgeCountA + 1).x() -
+ polygonB.at(i - edgeCountA).x(),
+ polygonB.at(i - edgeCountA + 1).y() -
+ polygonB.at(i - edgeCountA).y());
+ else
+ edge = QPointF(
+ polygonB.at(0).x() - polygonB.at(i - edgeCountA).x(),
+ polygonB.at(0).y() - polygonB.at(i - edgeCountA).y());
+ }
+
+ // ===== 1. Find if the polygons are currently intersecting =====
+
+ // Find the axis perpendicular to the current edge
+
+ Vector axis(-edge.y(), edge.x());
+ axis.normalize();
+
+ // Find the projection of the polygon on the current axis
+
+ qreal minA = 0;
+ qreal minB = 0;
+ qreal maxA = 0;
+ qreal maxB = 0;
+ projectPolygon(axis, polygonA, minA, maxA);
+ projectPolygon(axis, polygonB, minB, maxB);
+
+ // Check if the polygon projections are currentlty intersecting
+
+ qreal d = intervalDistance(minA, maxA, minB, maxB);
+ if (d > 0)
+ result.intersect = false;
+
+ // ===== 2. Now find if the polygons *will* intersect =====
+
+ // Project the velocity on the current axis
+
+ qreal velocityProjection = axis.dotProduct(velocity);
+
+ // Get the projection of polygon A during the movement
+
+ if (velocityProjection < 0)
+ minA += velocityProjection;
+ else
+ maxA += velocityProjection;
+
+ // Do the same test as above for the new projection
+
+ // d = intervalDistance(minA, maxA, minB, maxB);
+ // if (d > 0) result.willIntersect = false;
+ /*
+ qDebug() <<" ";
+ qDebug() << "edge="<<edge<<" ";
+ qDebug() <<"axis="<<axis<<" ";
+ qDebug() <<"dA=("<<minA<<","<<maxA<<") dB=("<<minB<<","<<maxB<<")";
+ qDebug() <<" d="<<d<<" ";
+ //qDebug() <<"minD="<<minIntervalDistance<<" ";
+ qDebug() <<"int="<<result.intersect<<" ";
+ //qDebug() <<"wint="<<result.willIntersect<<" ";
+ //qDebug() <<"velProj="<<velocityProjection<<" ";
+ qDebug() ;
+ */
+
+ if (result.intersect) // || result.willIntersect)
+ {
+ // Check if the current interval distance is the minimum one. If so
+ // store the interval distance and the current distance. This will
+ // be used to calculate the minimum translation vector
+
+ if (d < 0)
+ d = -d;
+ if (d < minIntervalDistance) {
+ minIntervalDistance = d;
+ // translationAxis = axis;
+ // qDebug() << "tAxix="<<translationAxis;
+
+ // QPointF t = polygonA.Center - polygonB.Center;
+ // QPointF t = polygonA.at(0) - polygonB.at(0);
+ // if (dotProduct(t,translationAxis) < 0)
+ // translationAxis = -translationAxis;
+ }
+ }
+ }
+
+ // The minimum translation vector
+ // can be used to push the polygons appart.
+
+ if (result.willIntersect)
+ result.minTranslation = translationAxis * minIntervalDistance;
+
+ return result;
+}
+
+/* The function can be used this way:
+ QPointF polygonATranslation = new QPointF();
+*/
+
+/*
+PolygonCollisionResult r = PolygonCollision(polygonA, polygonB, velocity);
+
+if (r.WillIntersect)
+ // Move the polygon by its velocity, then move
+ // the polygons appart using the Minimum Translation Vector
+ polygonATranslation = velocity + r.minTranslation;
+else
+ // Just move the polygon by its velocity
+ polygonATranslation = velocity;
+
+polygonA.Offset(polygonATranslation);
+
+*/
projects / sven / vym.git / blobdiff