/// \brief Get an accurate height and normal vector at a given coordinate
/// relative to this segment.
///
/// The height and surface normal are determined by finding the four adjacent
/// height points nearest to the coordinate, and interpolating between
/// those height values. The square area defined by the 4 height points is
/// considered as two triangles for the purposes of interpolation to ensure
/// that the calculated height falls on the surface rendered by a 3D
/// graphics engine from the same heightfield data. The line used to
/// divide the area is defined by the gradient y = x, so the first
/// triangle has relative vertex coordinates (0,0) (1,0) (1,1) and
/// the second triangle has vertex coordinates (0,0) (0,1) (1,1).
void Segment::getHeightAndNormal(float x, float y, float& h,
WFMath::Vector<3> &normal) const
{
// FIXME this ignores edges and corners
assert(x <= m_res);
assert(x >= 0.0f);
assert(y <= m_res);
assert(y >= 0.0f);
// get index of the actual tile in the segment
int tile_x = I_ROUND(std::floor(x));
int tile_y = I_ROUND(std::floor(y));
// work out the offset into that tile
float off_x = x - tile_x;
float off_y = y - tile_y;
float h1=get(tile_x, tile_y);
float h2=get(tile_x, tile_y+1);
float h3=get(tile_x+1, tile_y+1);
float h4=get(tile_x+1, tile_y);
// square is broken into two triangles
// top triangle |/
if ((off_x - off_y) <= 0.f) {
normal = WFMath::Vector<3>(h2-h3, h1-h2, 1.0f);
//normal for intersection of both triangles
if (off_x == off_y) {
normal += WFMath::Vector<3>(h1-h4, h4-h3, 1.0f);
}
normal.normalize();
h = h1 + (h3-h2) * off_x + (h2-h1) * off_y;
}
// bottom triangle /|
else {
normal = WFMath::Vector<3>(h1-h4, h4-h3, 1.0f);
normal.normalize();
h = h1 + (h4-h1) * off_x + (h3-h4) * off_y;
}
}
void TerrainPageShadow::updateShadow(const TerrainPageGeometry& geometry)
{
if (!mImage) {
mImage = new OgreImage(new Image::ImageBuffer(mTerrainPage.getBlendMapSize(), 1));
}
mImage->reset();
int pageSizeInVertices = mTerrainPage.getPageSize();
int pageSizeInMeters = pageSizeInVertices - 1;
//since Ogre uses a different coord system than WF, we have to do some conversions here
TerrainPosition origPosition(0, pageSizeInMeters - 1);
WFMath::Vector<3> wfLightDirection = mLightDirection;
wfLightDirection = wfLightDirection.normalize(1);
TerrainPosition position(origPosition);
auto data = mImage->getData();
for (int i = 0; i < pageSizeInMeters; ++i) {
position = origPosition;
position[1] = position[1] - i;
for (int j = 0; j < pageSizeInMeters; ++j) {
WFMath::Vector<3> normal;
if (geometry.getNormal(position, normal)) {
float dotProduct = WFMath::Dot(normal.normalize(1), wfLightDirection);
// if the dotProduct is > 0, the face is looking away from the sun
*data = static_cast<unsigned char>((1.0f - ((dotProduct + 1.0f) * 0.5f)) * 255);
} else {
*data = 0;
}
data++;
position[0] = position[0] + 1;
}
}
}
void Steering::update()
{
if (mSteeringEnabled) {
if (mUpdateNeeded) {
updatePath();
}
auto entity = mAvatar.getEntity();
if (!mPath.empty()) {
const auto& finalDestination = mPath.back();
auto entity3dPosition = entity->getViewPosition();
const WFMath::Point<2> entityPosition(entity3dPosition.x(), entity3dPosition.z());
//First check if we've arrived at our actual destination.
if (WFMath::Distance(WFMath::Point<2>(finalDestination.x(), finalDestination.z()), entityPosition) < 0.1f) {
//We've arrived at our destination. If we're moving we should stop.
if (mLastSentVelocity.isValid() && mLastSentVelocity != WFMath::Vector<2>::ZERO()) {
moveInDirection(WFMath::Vector<2>::ZERO());
}
stopSteering();
} else {
//We should send a move op if we're either not moving, or we've reached a waypoint, or we need to divert a lot.
WFMath::Point<2> nextWaypoint(mPath.front().x(), mPath.front().z());
if (WFMath::Distance(nextWaypoint, entityPosition) < 0.1f) {
mPath.pop_front();
nextWaypoint = WFMath::Point<2>(mPath.front().x(), mPath.front().z());
}
WFMath::Vector<2> velocity = nextWaypoint - entityPosition;
WFMath::Point<2> destination;
velocity.normalize();
if (mPath.size() == 1) {
//if the next waypoint is the destination we should send a "move to position" update to the server, to make sure that we stop when we've arrived.
//otherwise, if there's too much lag, we might end up overshooting our destination and will have to double back
destination = nextWaypoint;
}
//Check if we need to divert in order to avoid colliding.
WFMath::Vector<2> newVelocity;
bool avoiding = mAwareness.avoidObstacles(entityPosition, velocity * mSpeed, newVelocity);
if (avoiding) {
auto newMag = newVelocity.mag();
auto relativeMag = mSpeed / newMag;
velocity = newVelocity;
velocity.normalize();
velocity *= relativeMag;
mUpdateNeeded = true;
}
bool shouldSend = false;
if (velocity.isValid()) {
if (mLastSentVelocity.isValid()) {
//If the entity has stopped, and we're not waiting for confirmation to a movement request we've made, we need to start moving.
if (!entity->isMoving() && !mExpectingServerMovement) {
shouldSend = true;
} else {
auto currentTheta = std::atan2(mLastSentVelocity.y(), mLastSentVelocity.x());
auto newTheta = std::atan2(velocity.y(), velocity.x());
//If we divert too much from where we need to go we must adjust.
if (std::abs(currentTheta - newTheta) > WFMath::numeric_constants<double>::pi() / 20) {
shouldSend = true;
}
}
} else {
//If we've never sent a movement update before we should do that now.
shouldSend = true;
}
}
if (shouldSend) {
//If we're moving to a certain destination and aren't avoiding anything we should tell the server to move to the destination.
if (destination.isValid() && !avoiding) {
moveToPoint(WFMath::Point<3>(destination.x(), entity3dPosition.y(), destination.y()));
} else {
moveInDirection(velocity);
}
}
}
} else {
//We are steering, but the path is empty, which means we can't find any path. If we're moving we should stop movement.
//But we won't stop steering; perhaps we'll find a path later.
if (mLastSentVelocity.isValid() && mLastSentVelocity != WFMath::Vector<2>::ZERO()) {
moveInDirection(WFMath::Vector<2>::ZERO());
}
}
}
}
int main()
{
Mercator::Terrain terrain;
terrain.setBasePoint(0, 0, 2.8);
terrain.setBasePoint(1, 0, 7.1);
terrain.setBasePoint(0, 1, 0.2);
terrain.setBasePoint(1, 1, 14.7);
Mercator::Segment * segment = terrain.getSegment(0, 0);
if (segment == 0) {
std::cerr << "Segment not created by addition of required basepoints"
<< std::endl << std::flush;
return 1;
}
segment->populate();
//test box definitely outside terrain
WFMath::AxisBox<3> highab(WFMath::Point<3> (10.0, 10.0, segment->getMax() + 3.0),
WFMath::Point<3> (20.0, 20.0, segment->getMax() + 6.1));
if (Mercator::Intersect(terrain, highab)) {
std::cerr << "axisbox intersects with terrain even though it should be above it"
<< std::endl;
return 1;
}
//test box definitely inside terrain
WFMath::AxisBox<3> lowab(WFMath::Point<3> (10.0, 10.0, segment->getMin() - 6.1),
WFMath::Point<3> (20.0, 20.0, segment->getMax() - 3.0));
if (!Mercator::Intersect(terrain, lowab)) {
std::cerr << "axisbox does not intersect with terrain even though it should be below it"
<< std::endl;
return 1;
}
//test axis box moved from above terrain to below it.
bool inter=false;
float dz = highab.highCorner()[2] - highab.lowCorner()[2] - 0.1;
while (highab.highCorner()[2] > segment->getMin()) {
highab.shift(WFMath::Vector<3>(0.0, 0.0, -dz));
if (Mercator::Intersect(terrain, highab)) {
inter=true;
break;
}
}
if (!inter) {
std::cerr << "axisbox passed through terrain with no intersection"
<< std::endl;
return 1;
}
//test axisbox that spans two segments
terrain.setBasePoint(0, 2, 4.8);
terrain.setBasePoint(1, 2, 3.7);
Mercator::Segment *segment2 = terrain.getSegment(0, 1);
segment2->populate();
float segmax=std::max(segment->getMax(), segment2->getMax());
float segmin=std::min(segment->getMin(), segment2->getMin());
WFMath::AxisBox<3> ab(WFMath::Point<3> (50.0, 10.0, segmax + 3.0),
WFMath::Point<3> (70.0, 20.0, segmax + 6.1));
if (Mercator::Intersect(terrain, ab)) {
std::cerr << "axisbox2 intersects with terrain even though it should be above it"
<< std::endl;
return 1;
}
WFMath::AxisBox<3> ab2(WFMath::Point<3> (50.0, 10.0, segmin - 6.1),
WFMath::Point<3> (70.0, 20.0, segmin + 3.0));
if (!Mercator::Intersect(terrain, ab2)) {
std::cerr << "axisbox2 does not intersect with terrain even though it should be below it"
<< std::endl;
return 1;
}
WFMath::Point<3> intPoint;
WFMath::Vector<3> intNorm;
float par;
//test vertical ray
if (Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(0.0,0.0,50.0), intPoint, intNorm, par)) {
std::cerr << "vertical ray intersected when it shouldnt" << std::endl;
return 1;
}
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(0.0,0.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "vertical ray didnt intersect when it should" << std::endl;
return 1;
}
//test each quadrant
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(10.0,10.0,-100.0), intPoint, intNorm, par)) {
std::cerr << "quad1 ray didnt intersect when it should" << std::endl;
return 1;
}
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(10.0,-15.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "quad2 ray didnt intersect when it should" << std::endl;
return 1;
}
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(-10.0,-10.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "quad3 ray didnt intersect when it should" << std::endl;
return 1;
}
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(-10.0,10.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "quad4 ray didnt intersect when it should" << std::endl;
return 1;
}
//test dx==0 and dy==0
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(0.0,10.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "y+ ray didnt intersect when it should" << std::endl;
return 1;
}
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(0.0,-10.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "y- ray didnt intersect when it should" << std::endl;
return 1;
}
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(-10.0,0.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "x- ray didnt intersect when it should" << std::endl;
return 1;
}
if (!Mercator::Intersect(terrain, WFMath::Point<3>(20.1, 20.2, segmax + 3),
WFMath::Vector<3>(10.0,0.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "x+ ray didnt intersect when it should" << std::endl;
return 1;
}
//test a longer ray
if (!Mercator::Intersect(terrain, WFMath::Point<3>(-10.08, -20.37, segmax + 3),
WFMath::Vector<3>(100.0,183.0,-50.0), intPoint, intNorm, par)) {
std::cerr << "long ray didnt intersect when it should" << std::endl;
return 1;
}
//check the height value
float h;
WFMath::Vector<3> n;
terrain.getHeightAndNormal(intPoint[0], intPoint[1], h, n);
n.normalize();
if (n != intNorm) {
std::cerr << "calculated normal is different from getHeightAndNormal" << std::endl;
std::cerr << intPoint << std::endl;
std::cerr << intNorm << "!=" << n << std::endl;
// return 1;
}
// We can't check for equality here is it just doesn't work with
// floats. Look it up in any programming book if you don't believe me.
// - 20040721 <*****@*****.**>
if (fabs(h - intPoint[2]) > 0.00001) {
std::cerr << "calculated height is different from getHeightAndNormal" << std::endl;
std::cerr << h << "!=" << intPoint[2] << std::endl;
return 1;
}
return 0;
}