mouse_x(3alleg4)

✨ mouse_x — bestie, it's the mouse page ✨

okay so real talk, this is from the Allegro game programming library manual, and it's covering a whole lil squad of global variables: mouse_x, mouse_y, mouse_z, mouse_w, mouse_b, and mouse_pos. they all just hang out in global scope holding the mouse's position and button state. no cap. 🐭💖

🌸 SYNOPSIS 🌸

#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;

🎀 DESCRIPTION 🎀

So these are global variables and they hold the current mouse position plus the button state, okay? and here's the thing — wherever it's possible, these values get updated asynchronously, like they just do it themselves, main character energy, no help needed. ✨

BUT. if mouse_needs_poll() returns TRUE, bestie, you have to manually call poll_mouse() to refresh them with the current input state. it's giving "you gotta do it yourself", no shortcuts. 💅

Here's the breakdown of who holds what:

• mouse_x and mouse_y — these are integers ranging from zero all the way to the bottom right corner of the screen. iconic.
• mouse_z and mouse_w — these hold the current vertical and horizontal wheel position, but only when you're using an input driver that supports wheel mice. if your driver doesn't, well, not them being useful 💀
• mouse_b — this one's a bitfield showing the state of each button:
  • bit 0 → the left button
  • bit 1 → the right button
  • bit 2 → the middle button
  • higher bits → additional non standard mouse buttons might show up there, so like, extra buttons can absolutely be lurking up in there 🫶

Usage example, and it's literally this:

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

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

Now mouse_pos, she's the clever one. 🌈 She's got the current X coordinate in the upper 16 bits and the Y in the lower 16 bits. why do you care? because this is lowkey perfect for tight polling loops — imagine a mouse interrupt pops off between you reading the two separate variables, that's a whole vibe check failure 😭. but with mouse_pos you copy the value into a local variable with a single instruction and then split it up at your leisure. obsessed.

Example, verbatim:

int pos, x, y;

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

💜 SEE ALSO 💜

go read these too bestie, they're the whole friend group:

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

and that's the page, periodt. 🎀 this was the Allegro manual, version 4.4.3, and yeah the page is literally named mouse_x(3alleg4). go press some buttons, bestie, you've got this 💅✨🦋