/**
* Shift the points so that the center is at 0,0.
* That way, if everyone centers at the same place, we can measure
* the distance between each pair of points without worrying about
* where each point was originally drawn
* If we didn't do this, shapes drawn at the top of the screen
* would have a hard time matching shapes drawn at the bottom
* of the screen
*/
Path2D GeometricRecognizer::translateToOrigin(Path2D points)
{
Point2D c = centroid(points);
Path2D newPoints;
for (Path2DIterator i = points.begin(); i != points.end(); i++)
{
Point2D point = *i;
double qx = point.x - c.x;
double qy = point.y - c.y;
newPoints.push_back(Point2D(qx, qy));
}
return newPoints;
}
Point2D GeometricRecognizer::centroid(Path2D points)
{
double x = 0.0, y = 0.0;
for (Path2DIterator i = points.begin(); i != points.end(); i++)
{
Point2D point = *i;
x += point.x;
y += point.y;
}
x /= points.size();
y /= points.size();
return Point2D(x, y);
}
Path2D GeometricRecognizer::rotateBy(Path2D points, double rotation)
{
Point2D c = centroid(points);
//--- can't name cos; creates compiler error since VC++ can't
//--- tell the difference between the variable and function
double cosine = cos(rotation);
double sine = sin(rotation);
Path2D newPoints;
for (Path2DIterator i = points.begin(); i != points.end(); i++)
{
Point2D point = *i;
double qx = (point.x - c.x) * cosine - (point.y - c.y) * sine + c.x;
double qy = (point.x - c.x) * sine + (point.y - c.y) * cosine + c.y;
newPoints.push_back(Point2D(qx, qy));
}
return newPoints;
}
Path2D GeometricRecognizer::scaleToSquare(Path2D points)
{
//--- Figure out the smallest box that can contain the path
DollarRecognizer::Rectangle box = boundingBox(points);
Path2D newPoints;
for (Path2DIterator i = points.begin(); i != points.end(); i++)
{
Point2D point = *i;
//--- Scale the points to fit the main box
//--- So if we wanted everything 100x100 and this was 50x50,
//--- we'd multiply every point by 2
double scaledX = point.x * (this->squareSize / box.width);
double scaledY = point.y * (this->squareSize / box.height);
//--- Why are we adding them to a new list rather than
//--- just scaling them in-place?
// TODO: try scaling in place (once you know this way works)
newPoints.push_back(Point2D(scaledX, scaledY));
}
return newPoints;
}
Rectangle GeometricRecognizer::boundingBox(Path2D points)
{
double minX = MAX_DOUBLE;
double maxX = -MAX_DOUBLE;
double minY = MAX_DOUBLE;
double maxY = -MAX_DOUBLE;
for (Path2DIterator i = points.begin(); i != points.end(); i++)
{
Point2D point = *i;
if (point.x < minX)
minX = point.x;
if (point.x > maxX)
maxX = point.x;
if (point.y < minY)
minY = point.y;
if (point.y > maxY)
maxY = point.y;
}
Rectangle bounds(minX, minY, (maxX - minX), (maxY - minY));
return bounds;
}
