//  zoom.h
//
//  by John D. de Boer


//  Initialisation

void initzoom(void);
void giveprojcontrols(window *W, int PLACE, int AZIM, int ELEV, bool DownOnly);
//void give2Dcontrols(window *W, int PLACE, int AZIM);
void giveglobecontrols(window *W, int PLACE, int LAT, int LONG);


//  Controlling projections in windows

void scrolltoproj(window *W);
void projtoscroll(window *W);
bool projectionkey(keystroke *K);
bool projectionwheel(window *W, short DX, short DY);
//bool projcontent(mouseclick *E);
//void adjustprojcontrols(window *W, int STATE);


//  These routines allow the user to drag a point in a perspective view, or
//  on the surface of an opaque unit sphere, with the view angles being slaved
//  to satisfy the new orientation of the sphere

typedef struct {
bool   good,   //  struct has been initialised successfully
       same,   //  whether mouse has remained stationary since last draw
       did;    //  whether any dragging took place
window *wind;  //  window in which drag takes place
point  start,  //  start point of drag
       end;    //  current or end point of drag
vector where;  //  view angle or terrestrial location of mouse-down event (normalised)
real   azim,   //  new view azimuth as a result of drag
       elev;   //  new view elevation as a result of drag
} projdragtask;

void initprojdrag(mouseclick *M, projdragtask *T);
void trackprojdrag(projdragtask *T, point P);

void initspheredrag(mouseclick *M, projdragtask *T);
void trackspheredrag(projdragtask *T, point P);