//--------------------------------------------------------------------------------------------------
/// Walk forward backward along the current camera direction
///
/// \return Returns true if input caused changes to the camera an false if no changes occurred
///
/// \remarks As this function moves the camera, it will have no effect when projection is orthographic
/// \todo Needs better control over movement when camera position gets close to the rotation point.
//--------------------------------------------------------------------------------------------------
bool ManipulatorTrackball::walk(int posX, int posY)
{
if (m_camera.isNull()) return false;
if (posX == m_lastPosX && posY == m_lastPosY) return false;
const double vpPixSizeY = m_camera->viewport()->height();
if (vpPixSizeY <= 0) return false;
// !!!!
// Should be a member variable, settable as a ratio of the model bounding box/sphere
const double minWalkTargetDistance = 1.0;
const double ty = (m_lastPosY - posY)/vpPixSizeY;
// Determine target distance to travel along camera direction
// This is the distance that we will move the camera in response to a full (whole viewport) movement of the mouse
const Vec3d camDir = m_camera->direction();
const Vec3d vDiff = m_rotationPoint - m_walkStartCameraPos;
double targetDist = Math::abs(camDir*vDiff);
if (targetDist < minWalkTargetDistance) targetDist = minWalkTargetDistance;
// Figure out movement to append
double moveDist = ty*targetDist*m_walkSensitivity;
Vec3d moveVec = camDir*moveDist;
Mat4d viewMat = m_camera->viewMatrix();
viewMat.translatePostMultiply(moveVec);
m_camera->setViewMatrix(viewMat);
m_lastPosX = posX;
m_lastPosY = posY;
return true;
}
//--------------------------------------------------------------------------------------------------
/// Pan the camera up/down and left/right
///
/// \return Returns true if input caused changes to the camera an false if no changes occurred
//--------------------------------------------------------------------------------------------------
bool ManipulatorTrackball::pan(int posX, int posY)
{
if (m_camera.isNull()) return false;
if (posX == m_lastPosX && posY == m_lastPosY) return false;
const double vpPixSizeX = m_camera->viewport()->width();
const double vpPixSizeY = m_camera->viewport()->height();
if (vpPixSizeX <= 0 || vpPixSizeY <= 0) return false;
// Normalized movement in screen plane
double tx = (posX - m_lastPosX)/vpPixSizeX;
double ty = (posY - m_lastPosY)/vpPixSizeY;
// Viewport size in world coordinates
const double aspect = m_camera->aspectRatio();
const double vpWorldSizeY = m_camera->frontPlaneFrustumHeight();
const double vpWorldSizeX = vpWorldSizeY*aspect;
const Vec3d camUp = m_camera->up();
const Vec3d camRight = m_camera->right();
Vec3d translation(0, 0, 0);
Camera::ProjectionType projType = m_camera->projection();
if (projType == Camera::PERSPECTIVE)
{
const Vec3d camPos = m_camera->position();
const Vec3d camDir = m_camera->direction();
const double nearPlane = m_camera->nearPlane();
// Compute distance from camera to rotation point projected onto camera forward direction
const Vec3d vDiff = m_rotationPoint - camPos;
const double camRotPointDist = Math::abs(camDir*vDiff);
Vec3d vX = camRight*((tx*vpWorldSizeX)/nearPlane)*camRotPointDist;
Vec3d vY = camUp*((ty*vpWorldSizeY)/nearPlane)*camRotPointDist;
translation = vX + vY;
}
else if (projType == Camera::ORTHO)
{
Vec3d vX = camRight*tx*vpWorldSizeX;
Vec3d vY = camUp*ty*vpWorldSizeY;
translation = vX + vY;
}
Mat4d viewMat = m_camera->viewMatrix();
viewMat.translatePostMultiply(translation);
m_camera->setViewMatrix(viewMat);
m_lastPosX = posX;
m_lastPosY = posY;
return true;
}
//--------------------------------------------------------------------------------------------------
/// Rotate
///
/// \return Returns true if input caused changes to the camera an false if no changes occurred
//--------------------------------------------------------------------------------------------------
bool ManipulatorTrackball::rotate(int posX, int posY)
{
if (m_camera.isNull()) return false;
if (posX == m_lastPosX && posY == m_lastPosY) return false;
const double vpPixSizeX = m_camera->viewport()->width();
const double vpPixSizeY = m_camera->viewport()->height();
if (vpPixSizeX <= 0 || vpPixSizeY <= 0) return false;
const double vpPosX = posX - static_cast<int>(m_camera->viewport()->x());
const double vpPosY = posY - static_cast<int>(m_camera->viewport()->y());
const double vpLastPosX = m_lastPosX - static_cast<int>(m_camera->viewport()->x());
const double vpLastPosY = m_lastPosY - static_cast<int>(m_camera->viewport()->y());
// Scale the new/last positions to the range [-1.0, 1.0]
double newPosX = 2.0*(vpPosX/vpPixSizeX) - 1.0;
double newPosY = 2.0*(vpPosY/vpPixSizeY) - 1.0;
double lastPosX = 2.0*(vpLastPosX/vpPixSizeX) - 1.0;
double lastPosY = 2.0*(vpLastPosY/vpPixSizeY) - 1.0;
Mat4d viewMat = m_camera->viewMatrix();
// Compute rotation quaternion
Quatd rotQuat = trackballRotation(lastPosX, lastPosY, newPosX, newPosY, viewMat, m_rotateSensitivity);
// Update navigation by modifying the view matrix
Mat4d rotMatr = rotQuat.toMatrix4();
rotMatr.translatePostMultiply(-m_rotationPoint);
rotMatr.translatePreMultiply(m_rotationPoint);
viewMat = viewMat*rotMatr;
m_camera->setViewMatrix(viewMat);
m_lastPosX = posX;
m_lastPosY = posY;
return true;
}
