DOKK / manpages / debian 10 / allegro4-doc / mouse_b.3alleg4.en
mouse_x(3alleg4) Allegro manual mouse_x(3alleg4)

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. Example:


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)

version 4.4.2 Allegro