GreatCircleArc::GreatCircleArc(double startLat, double startLong,
double endLat, double endLong,
VisualizationState & visualizationState)
{
m_visualizationState = &visualizationState;
// get the output projection
const HuginBase::PanoramaOptions & options = *(visualizationState.GetOptions());
// make an image to transform spherical coordinates into the output projection
HuginBase::SrcPanoImage equirectangularImage;
equirectangularImage.setProjection(HuginBase::SrcPanoImage::EQUIRECTANGULAR);
equirectangularImage.setHFOV(360.0);
equirectangularImage.setSize(vigra::Size2D(360.0, 180.0));
// make a transformation from spherical coordinates to the output projection
HuginBase::PTools::Transform transform;
transform.createInvTransform(equirectangularImage, options);
m_xscale = visualizationState.GetScale();
/**Handle case where the points are opposite sides of the sphere
* (i.e. The angle startLat is -endLat and startLong is -endLong.)
* There are infinetly many great circles in this case, we pick one going
* through (180, 90), by splitting the problem in two.
*/
if (startLat == 360.0 - endLat && startLong == 180.0 - endLong)
{
// we should probably check to see if we already go through (180, 90).
if (startLat == 180.0 && startLong == 90.0)
{
// foiled again: pick one going through (180, 0) instead.
*this = GreatCircleArc(startLat, startLong, 180.0, 0.0, visualizationState);
GreatCircleArc other(180.0, 0.0, endLat, endLong, visualizationState);
m_lines.insert(m_lines.end(), other.m_lines.begin(), other.m_lines.end());
return;
}
*this = GreatCircleArc(startLat, startLong, 180.0, 90.0, visualizationState);
GreatCircleArc other(180.0, 90.0, endLat, endLong, visualizationState);
m_lines.insert(m_lines.end(), other.m_lines.begin(), other.m_lines.end());
return;
}
// convert start and end positions so that they don't go across the +/-180
// degree seam
if (startLat < 90.0 && endLat > 270.0)
{
endLat -= 360.0;
}
// convert to radians
startLat *= (M_PI / 180.0);
startLong *= (M_PI / 180.0);
endLat *= (M_PI / 180.0);
endLong *= (M_PI / 180.0);
// find sines and cosines, they are used multiple times.
double sineStartLat = std::sin(startLat);
double sineStartLong = std::sin(startLong);
double sineEndLat = std::sin(endLat);
double sineEndLong = std::sin(endLong);
double cosineStartLat = std::cos(startLat);
double cosineStartLong = std::cos(startLong);
double cosineEndLat = std::cos(endLat);
double cosineEndLong = std::cos(endLong);
/* to get points on the great circle, we linearly interpolate between the
* two 3D coordinates for the given spherical coordinates, then normalise
* the vector to get back on the sphere. This works everywhere except exact
* opposite points, where we'll get the original points repeated several
* times (and if we are even more unlucky we will hit the origin where the
* normal isn't defined.)
*/
// convert locations to 3d coordinates.
double p1[3] = {cosineStartLat * sineStartLong, sineStartLat * sineStartLong, cosineStartLong};
double p2[3] = {cosineEndLat * sineEndLong, sineEndLat * sineEndLong, cosineEndLong};
///@todo don't check the +/- 180 degree boundary when projection does not break there.
bool hasSeam = true;
// draw a line strip and transform the coordinates as we go.
double b1 = 0.0;
double b2 = 1.0;
const double bDifference = 1.0 / double(segments);
// for discontinuity detection.
int lastSegment = 1;
// The last processed vertex's position.
hugin_utils::FDiff2D last_vertex;
/* true if we shouldn't use last_vertex to make a line segment
* i.e. We just crossed a discontinuity. */
bool skip = true;
for (unsigned int segment_index = 0; segment_index < segments;
segment_index++, b1 += bDifference, b2 -= bDifference)
{
// linearly interpolate positions
double v[3] = {p1[0] * b1 + p2[0] * b2, p1[1] * b1 + p2[1] * b2, p1[2] * b1 + p2[2] * b2};
// normalise
double length = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
v[0] /= length;
v[1] /= length;
v[2] /= length;
/*double longitude = atan2(numerator,
cosineStartLong * (c1 * std::sin(latitude) -
c2 * std::cos(latitude)));*/
double longitude = std::acos(v[2]);
// acos returns values between 0 and M_PI. The other
// latitudes are on the back of the sphere, so check y coordinate (v1)
double latitude = std::acos(v[0] / std::sin(longitude));
if (v[1] < 0.0)
{
// on the back.
latitude = -latitude + 2 * M_PI;
}
double vx, vy;
bool infront = transform.transformImgCoord(vx,
vy,
latitude * 180.0 / M_PI,
longitude * 180.0 / M_PI);
// don't draw across +/- 180 degree seems.
if (hasSeam)
{
// we divide the width of the panorama into 3 segments. If we jump
// across the middle section, we split the line into two.
int newSegment = vx / (options.getWidth() / 3);
if ((newSegment < 1 && lastSegment > 1) ||
(newSegment > 1 && lastSegment < 1))
{
skip = true;
}
lastSegment = newSegment;
}
if (infront)
{
if (!skip)
{
LineSegment line;
line.vertices[0] = last_vertex;
line.vertices[1] = hugin_utils::FDiff2D(vx, vy);
m_lines.push_back(line);
}
// The next line segment should be a valid one.
last_vertex = hugin_utils::FDiff2D(vx, vy);
skip = false;
} else {
skip = true;
}
}
}
void PreviewLayoutLinesTool::updateLineInformation()
{
m_lines.clear();
const HuginBase::Panorama & pano = *(helper->GetPanoramaPtr());
unsigned int numberOfImages = pano.getNrOfImages();
HuginBase::UIntSet active_images = pano.getActiveImages();
// make a line for every image pair, but set the unneeded ones as dud.
// This is for constant look up times when we scan control points.
m_lines.resize(numberOfImages * numberOfImages);
unsigned int numberOfControlPoints = pano.getNrOfCtrlPoints();
// loop over all control points to count them and get error statistics.
for (unsigned int cpi = 0 ; cpi < numberOfControlPoints ; cpi++)
{
const HuginBase::ControlPoint & cp = pano.getCtrlPoint(cpi);
unsigned int low_index, high_index;
if (cp.image1Nr < cp.image2Nr)
{
low_index = cp.image1Nr;
high_index = cp.image2Nr;
} else {
low_index = cp.image2Nr;
high_index = cp.image1Nr;
}
// find the line.
// We use the formula in the line below to record image numbers to each
// line later.
LineDetails & line = m_lines[low_index * numberOfImages + high_index];
// update control point count.
line.numberOfControlPoints++;
// update error statistics
line.totalError += cp.error;
if (cp.error > line.worstError)
{
line.worstError = cp.error;
}
}
/* Find some locations of the images. We will test if they overlap using
* these locations. We don't need the last image as we can always take the
* smallest numbered image as the source of points.
*/
/** @todo Check both ways around.
* This only checks if points from the smallest numbered image are
* within the largest numbered image. If the first image is huge compared to
* the second, then it many points will miss and we might not reach the
* target even if the second image is contained within the first.
*/
std::vector<PosMap> positions(pano.getNrOfImages() - 1);
for (unsigned int i = 0; i < numberOfImages - 1; i++)
{
const HuginBase::SrcPanoImage & img = pano.getImage(i);
for (unsigned int x = 0; x < SAMPLE_FREQUENCY; x++)
{
for (unsigned int y = 0; y < SAMPLE_FREQUENCY; y++)
{
// scale (x, y) so it is always within the cropped region of the
// image.
vigra::Rect2D c = img.getCropRect();
/** @todo Use only points inside the circle when circular crop
* is used.
*/
double xc = double (x) / double (SAMPLE_FREQUENCY)
* double(c.width()) + c.left();
double yc = double (y) / double (SAMPLE_FREQUENCY)
* double(c.height()) + c.top();
// now look up (xc, yc) in the image, find where in the panorama
// it ends up.
m_transforms[i]->transformImgCoord (
positions[i][x][y].x, positions[i][x][y].y,
xc, yc );
}
}
}
// write other line data.
for (unsigned int i = 0; i < numberOfImages; i++)
{
for (unsigned int j = 0; j < numberOfImages; j++)
{
LineDetails & line = m_lines[i * numberOfImages + j];
line.image1 = i;
line.image2 = j;
/// test if the line should be visible.
if (!(set_contains(active_images, i) &&
set_contains(active_images, j)))
{
// At least one of the images is hidden, so don't show the line.
line.dud = true;
}
else if (line.numberOfControlPoints > 0)
{
line.dud = false;
} else if (i >= j) {
// We only use lines where image1 is the lowest numbered image.
// We don't bother with lines from one image to the same one.
line.dud = true;
} else {
// test overlapping regions.
HuginBase::PTools::Transform transform;
ViewState & viewState = *helper->GetViewStatePtr();
HuginBase::SrcPanoImage & src = *viewState.GetSrcImage(j);
transform.createTransform(src, *(viewState.GetOptions()));
unsigned int overlapingSamples = 0;
for (unsigned int x = 0; x < SAMPLE_FREQUENCY; x++)
{
for (unsigned int y = 0; y < SAMPLE_FREQUENCY; y++)
{
// check if mapping a point that was found earilier to
// be inside an image in panorama space is inside the
// other image when transformed from panorama to image.
double dx, dy;
transform.transformImgCoord (
dx, dy,
positions[i][x][y].x,
positions[i][x][y].y
);
if (src.isInside(vigra::Point2D((int) dx, (int) dy)))
{
// they overlap
overlapingSamples++;
}
}
}
// If the overlap isn't big enough, the line isn't used.
line.dud = (overlapingSamples < MIN_SAMPLE_OVERLAPS);
}
if (!line.dud)
{
line.arc = GreatCircleArc(m_imageCentresSpherical[i].x,
m_imageCentresSpherical[i].y,
m_imageCentresSpherical[j].x,
m_imageCentresSpherical[j].y,
*(helper->GetVisualizationStatePtr()));
}
}
}
}
void GreatCircles::drawLineFromSpherical(double startLat, double startLong,
double endLat, double endLong, double width)
{
DEBUG_ASSERT(m_visualizationState);
GreatCircleArc(startLat, startLong, endLat, endLong, *m_visualizationState).draw(true, width);
}
