void ArcBall::mouseDragged(int mouseX, int mouseY) {
v_drag = mouse_to_sphere(mouseX, mouseY);
QQuaternion q_drag( QVector3D::dotProduct(v_down, v_drag),
QVector3D::crossProduct(v_down, v_drag));
q_now = q_drag * q_down;
}
void Arcball::mouse_motion(int x, int y, int shift, int ctrl, int alt)
{
/* Set the X constraint if CONTROL key is pressed, Y if ALT key */
set_constraints( ctrl != 0, alt != 0 );
vec2 new_pt( (float)x, (float) y );
vec3 v0 = mouse_to_sphere( down_pt );
vec3 v1 = mouse_to_sphere( new_pt );
vec3 cross = v0^v1;
q_drag.set( cross, v0 * v1 );
// *rot_ptr = (q_drag * q_now).to_mat4();
mat4 temp = q_drag.to_mat4();
*rot_ptr = *rot_ptr * temp;
down_pt = new_pt;
/* We keep a copy of the current incremental rotation (= q_drag) */
q_increment = q_drag;
rot_increment = q_increment.to_mat4();
set_constraints(false, false);
if ( q_increment.s < .999999 )
{
is_spinning = true;
zero_increment = false;
}
else
{
is_spinning = false;
zero_increment = true;
}
}
void ArcBall::mousePressed(int mouseX, int mouseY) {
v_down = mouse_to_sphere(mouseX, mouseY);
q_down = q_now;
}
