Waits for mouse button press
int MPE_Get_mouse_press( graph, x, y, button )
int *x, *y, *button;
- MPE graphics handle
|x ||horizontal coordinate of the point where the mouse button was pressed
|y ||vertical coordinate of the point where the mouse button was pressed
|button ||which button was pressed: MPE_BUTTON[1-5]
This routine waits for mouse button press, blocking
until the mouse button is pressed inside this MPE window.
When pressed, returns the coordinate relative to the upper right of
this MPE window and the button that was pressed.