Provided by: allegro4-doc_4.4.3.1-1_all bug


       mouse_x,  mouse_y,  mouse_z,  mouse_w, mouse_b, mouse_pos - Global variable with the mouse
       position/button state. Allegro game programming library.


       #include <allegro.h>

       extern volatile int mouse_x;

       extern volatile int mouse_y;

       extern volatile int mouse_z;

       extern volatile int mouse_w;

       extern volatile int mouse_b;

       extern volatile int mouse_pos;


       Global variables containing  the  current  mouse  position  and  button  state.   Wherever
       possible  these  values  will be updated asynchronously, but if mouse_needs_poll() returns
       TRUE, you must manually call poll_mouse() to update them with the current input state. The
       `mouse_x'  and  `mouse_y'  positions  are  integers  ranging from zero to the bottom right
       corner of the screen. The `mouse_z' and `mouse_w' variables hold the current vertical  and
       horizontal  wheel  position,  when  using  an  input  driver that supports wheel mice. The
       `mouse_b' variable is a bitfield indicating the state of each button: bit 0  is  the  left
       button,   bit  1  the  right,  and  bit 2 the middle button. Additional non standard mouse
       buttons might be available as higher bits in this variable. Usage example:

          if (mouse_b & 1)
             printf("Left button is pressed\n");

          if (!(mouse_b & 2))
             printf("Right button is not pressed\n");

       The `mouse_pos' variable has the current X coordinate in the upper 16 bits and  the  Y  in
       the lower 16 bits. This may be useful in tight polling loops where a mouse interrupt could
       occur between your reading of the two separate variables, since you can  copy  this  value
       into  a  local  variable  with  a single instruction and then split it up at your leisure.

          int pos, x, y;

          pos = mouse_pos;
          x = pos >> 16;
          y = pos & 0x0000ffff;


       install_mouse(3alleg4), poll_mouse(3alleg4), mouse_needs_poll(3alleg4),  exalpha(3alleg4),
       exlights(3alleg4), exmouse(3alleg4), exshade(3alleg4), exspline(3alleg4), extrans(3alleg4)