void GraphicCamera::MouseEventHandler(int button, int state, int x, int y){
double realy, wx, wy, wz;
// if ALT key used
// int mode = glutGetModifiers();
if (state == GLUT_UP && CameraMode != kINACTIVE) {
current_elev += dt_elev;
current_azim += dt_azim;
//reset change in elevation and roll of the camera;
dt_elev = dt_azim = 0.0;
CameraMode = kINACTIVE;
} else if (state == GLUT_DOWN) {
MouseStartX = MousePrevX = x;
MouseStartY = MousePrevY = y;
switch(button) {
case GLUT_LEFT_BUTTON:
//rotating
CameraMode = kROTATE;
break;
case GLUT_MIDDLE_BUTTON:
// translating
CameraMode = kTRANSLATE;
glGetIntegerv(GL_VIEWPORT, ViewPort);
glGetDoublev(GL_MODELVIEW_MATRIX, MvMat.GetPtr());
glGetDoublev(GL_PROJECTION_MATRIX, ProjMat.GetPtr());
// height of window in pixels
realy = ViewPort[3] - y - 1;
gluProject(aim_.x(), aim_.y(), aim_.z(), MvMat.GetPtr(),
ProjMat.GetPtr(), ViewPort, &wx, &wy, &wz);
gluUnProject((GLdouble) x, (GLdouble) realy, wz, MvMat.GetPtr(),
ProjMat.GetPtr(), ViewPort, &PrevMousePos.x(),
&PrevMousePos.y(), &PrevMousePos.z());
break;
case GLUT_RIGHT_BUTTON:
CameraMode = kZOOM;
break;
}
}
}
void GraphicCamera::MouseMotionEventHandler(int x, int y) {
int mouse_dx, mouse_dy, d;
double z;
Vec3d mouse_pos, dir;
Vec3d WndX, WndY, WndZ;
float realy;
double wx, wy, wz;
if (CameraMode != kINACTIVE) {
mouse_dx = x - MousePrevX;
mouse_dy = y - MousePrevY;
if (abs(mouse_dx) > abs(mouse_dy)) {
d = mouse_dx;
} else {
d = mouse_dy;
}
switch(CameraMode) {
case kZOOM:
z = (double) d / 100.0;
dir = aim_ - pos_;
if (dir.Norm() < 0.1 && z > 0) {
z *= 10.0;
aim_ = aim_ + z * dir;
}
pos_ = pos_ + z * dir;
break;
case kROTATE:
dt_azim = ((double) (x - MouseStartX)) / 5.0;
dt_elev = ((double) (y - MouseStartY)) / 5.0;
loc_dt_azim = ((double) mouse_dx) / 5.0;
loc_dt_elev = ((double) mouse_dy) / 5.0;
WndX = {1.0, 0.0, 0.0};
WndY = {0.0, 1.0, 0.0};
RotateX(WndX, current_elev + dt_elev);
RotateY(WndX, current_azim + dt_azim);
WndX.z() *= -1;
RotateX(WndY, current_elev + dt_elev);
RotateY(WndY, current_azim + dt_azim);
WndY.z() *= -1;
WndZ = (WndX % WndY).Normalization();
ArbitraryRotate(WndX, WndY, WndZ, loc_dt_elev, 0, pos_, aim_);
ArbitraryRotate(Vec3d(1, 0, 0), Vec3d(0, 1, 0), Vec3d(0, 0, 1), 0,
-loc_dt_azim, pos_, aim_);
up_ = WndY.Normalization();
break;
case kTRANSLATE:
realy = ViewPort[3] - y - 1;
gluProject(aim_.x(), aim_.y(), aim_.z(), MvMat.GetPtr(),
ProjMat.GetPtr(), ViewPort,
&wx, &wy, &wz);
gluUnProject((GLdouble) x, (GLdouble) realy, wz, MvMat.GetPtr(),
ProjMat.GetPtr(),
ViewPort, &mouse_pos.x(), &mouse_pos.y(),
&mouse_pos.z());
// move both the camera position and its aim coordinate
dir = mouse_pos - PrevMousePos;
pos_ = pos_ - dir;
aim_ = aim_ - dir;
PrevMousePos = mouse_pos;
break;
}
MousePrevX = x;
MousePrevY = y;
}
}
