Mouse routines
- ALLEGRO_MOUSE_STATE
- al_install_mouse
- al_is_mouse_installed
- al_uninstall_mouse
- al_get_mouse_num_axes
- al_get_mouse_num_buttons
- al_get_mouse_state
- al_get_mouse_state_axis
- al_mouse_button_down
- al_set_mouse_xy
- al_set_mouse_z
- al_set_mouse_w
- al_set_mouse_axis
- al_get_mouse_event_source
- al_set_mouse_wheel_precision
- al_get_mouse_wheel_precision
- Mouse cursors
These functions are declared in the main Allegro header file:
#include <allegro5/allegro.h>
ALLEGRO_MOUSE_STATE
typedef struct ALLEGRO_MOUSE_STATE ALLEGRO_MOUSE_STATE;
typedef struct ALLEGRO_MOUSE_STATE ALLEGRO_MOUSE_STATE;
typedef struct ALLEGRO_MOUSE_STATE ALLEGRO_MOUSE_STATE;
Public fields (read only):
- x - mouse x position
- y - mouse y position
- w, z - mouse wheel position (2D 'ball')
buttons - mouse buttons bitfield
The zeroth bit is set if the primary mouse button is held down, the first bit is set if the secondary mouse button is held down, and so on.
pressure - pressure, ranging from
0.0
to1.0
See also: al_get_mouse_state, al_get_mouse_state_axis, al_mouse_button_down
al_install_mouse
bool al_install_mouse(void)
Install a mouse driver.
Returns true if successful. If a driver was already installed, nothing happens and true is returned.
al_is_mouse_installed
bool al_is_mouse_installed(void)
Returns true if al_install_mouse was called successfully.
al_uninstall_mouse
void al_uninstall_mouse(void)
Uninstalls the active mouse driver, if any. This will automatically unregister the mouse event source with any event queues.
This function is automatically called when Allegro is shut down.
al_get_mouse_num_axes
unsigned int al_get_mouse_num_axes(void)
Return the number of axes on the mouse. The first axis is 0.
See also: al_get_mouse_num_buttons
al_get_mouse_num_buttons
unsigned int al_get_mouse_num_buttons(void)
Return the number of buttons on the mouse. The first button is 1.
See also: al_get_mouse_num_axes
al_get_mouse_state
void al_get_mouse_state(ALLEGRO_MOUSE_STATE *ret_state)
Save the state of the mouse specified at the time the function is called into the given structure.
Example:
ALLEGRO_MOUSE_STATE state;
al_get_mouse_state(&state);
if (state.buttons & 1) {
/* Primary (e.g. left) mouse button is held. */
printf("Mouse position: (%d, %d)\n", state.x, state.y);
}
if (state.buttons & 2) {
/* Secondary (e.g. right) mouse button is held. */
}
if (state.buttons & 4) {
/* Tertiary (e.g. middle) mouse button is held. */
}
See also: ALLEGRO_MOUSE_STATE, al_get_mouse_state_axis, al_mouse_button_down
al_get_mouse_state_axis
int al_get_mouse_state_axis(const ALLEGRO_MOUSE_STATE *state, int axis)
Extract the mouse axis value from the saved state. The axes are numbered from 0, in this order: x-axis, y-axis, z-axis, w-axis.
See also: ALLEGRO_MOUSE_STATE, al_get_mouse_state, al_mouse_button_down
al_mouse_button_down
bool al_mouse_button_down(const ALLEGRO_MOUSE_STATE *state, int button)
Return true if the mouse button specified was held down in the state specified. Unlike most things, the first mouse button is numbered 1.
See also: ALLEGRO_MOUSE_STATE, al_get_mouse_state, al_get_mouse_state_axis
al_set_mouse_xy
bool al_set_mouse_xy(ALLEGRO_DISPLAY *display, int x, int y)
Try to position the mouse at the given coordinates on the given display. The mouse movement resulting from a successful move will generate an ALLEGRO_EVENT_MOUSE_WARPED event.
Returns true on success, false on failure.
See also: al_set_mouse_z, al_set_mouse_w
al_set_mouse_z
bool al_set_mouse_z(int z)
Set the mouse wheel position to the given value.
Returns true on success, false on failure.
See also: al_set_mouse_w
al_set_mouse_w
bool al_set_mouse_w(int w)
Set the second mouse wheel position to the given value.
Returns true on success, false on failure.
See also: al_set_mouse_z
al_set_mouse_axis
bool al_set_mouse_axis(int which, int value)
Set the given mouse axis to the given value.
The axis number must not be 0 or 1, which are the X and Y axes. Use al_set_mouse_xy for that.
Returns true on success, false on failure.
See also: al_set_mouse_xy, al_set_mouse_z, al_set_mouse_w
al_get_mouse_event_source
ALLEGRO_EVENT_SOURCE *al_get_mouse_event_source(void)
Retrieve the mouse event source. All mouse events are generated by this event source.
Returns NULL if the mouse subsystem was not installed.
al_set_mouse_wheel_precision
void al_set_mouse_wheel_precision(int precision)
Sets the precision of the mouse wheel (the z and w coordinates). This precision manifests itself as a multiplier on the dz
and dw
fields in mouse events. It also affects the z
and w
fields of events and ALLEGRO_MOUSE_STATE, but not in a simple way if you alter the precision often, so it is suggested to reset those axes to 0 when you change precision. Setting this to a high value allows you to detect small changes in those two axes for some high precision mice. A flexible way of using this precision is to set it to a high value (120 is likely sufficient for most, if not all, mice) and use a floating point dz
and dw
like so:
al_set_mouse_wheel_precision(120);
ALLEGRO_EVENT event;
al_wait_for_event(event_queue, &event);
if (event.type == ALLEGRO_EVENT_MOUSE_AXES) {
double dz = (double)event.mouse.dz / al_get_mouse_wheel_precision();
/* Use dz in some way... */
}
Precision is set to 1 by default. It is impossible to set it to a lower precision than that.
Since: 5.1.10
See also: al_get_mouse_wheel_precision
al_get_mouse_wheel_precision
int al_get_mouse_wheel_precision(void)
Gets the precision of the mouse wheel (the z and w coordinates).
Since: 5.1.10
See also: al_set_mouse_wheel_precision
Mouse cursors
al_create_mouse_cursor
ALLEGRO_MOUSE_CURSOR *al_create_mouse_cursor(ALLEGRO_BITMAP *bmp,
int x_focus, int y_focus)
Create a mouse cursor from the bitmap provided. x_focus
and y_focus
describe the bit of the cursor that will represent the actual mouse position.
Returns a pointer to the cursor on success, or NULL on failure.
See also: al_set_mouse_cursor, al_destroy_mouse_cursor
al_destroy_mouse_cursor
void al_destroy_mouse_cursor(ALLEGRO_MOUSE_CURSOR *cursor)
Free the memory used by the given cursor.
Has no effect if cursor
is NULL.
See also: al_create_mouse_cursor
al_set_mouse_cursor
bool al_set_mouse_cursor(ALLEGRO_DISPLAY *display, ALLEGRO_MOUSE_CURSOR *cursor)
Set the given mouse cursor to be the current mouse cursor for the given display.
If the cursor is currently 'shown' (as opposed to 'hidden') the change is immediately visible.
Returns true on success, false on failure.
See also: al_set_system_mouse_cursor, al_show_mouse_cursor, al_hide_mouse_cursor
al_set_system_mouse_cursor
bool al_set_system_mouse_cursor(ALLEGRO_DISPLAY *display,
ALLEGRO_SYSTEM_MOUSE_CURSOR cursor_id)
Set the given system mouse cursor to be the current mouse cursor for the given display. If the cursor is currently 'shown' (as opposed to 'hidden') the change is immediately visible.
If the cursor doesn't exist on the current platform another cursor will be silently be substituted.
The cursors are:
- ALLEGRO_SYSTEM_MOUSE_CURSOR_DEFAULT
- ALLEGRO_SYSTEM_MOUSE_CURSOR_ARROW
- ALLEGRO_SYSTEM_MOUSE_CURSOR_BUSY
- ALLEGRO_SYSTEM_MOUSE_CURSOR_QUESTION
- ALLEGRO_SYSTEM_MOUSE_CURSOR_EDIT
- ALLEGRO_SYSTEM_MOUSE_CURSOR_MOVE
- ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_N
- ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_W
- ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_S
- ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_E
- ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_NW
- ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_SW
- ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_SE
- ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_NE
- ALLEGRO_SYSTEM_MOUSE_CURSOR_PROGRESS
- ALLEGRO_SYSTEM_MOUSE_CURSOR_PRECISION
- ALLEGRO_SYSTEM_MOUSE_CURSOR_LINK
- ALLEGRO_SYSTEM_MOUSE_CURSOR_ALT_SELECT
- ALLEGRO_SYSTEM_MOUSE_CURSOR_UNAVAILABLE
Returns true on success, false on failure.
See also: al_set_mouse_cursor, al_show_mouse_cursor, al_hide_mouse_cursor
al_get_mouse_cursor_position
bool al_get_mouse_cursor_position(int *ret_x, int *ret_y)
On platforms where this information is available, this function returns the global location of the mouse cursor, relative to the desktop. You should not normally use this function, as the information is not useful except for special scenarios as moving a window.
Returns true on success, false on failure.
al_hide_mouse_cursor
bool al_hide_mouse_cursor(ALLEGRO_DISPLAY *display)
Hide the mouse cursor in the given display. This has no effect on what the current mouse cursor looks like; it just makes it disappear.
Returns true on success (or if the cursor already was hidden), false otherwise.
See also: al_show_mouse_cursor
al_show_mouse_cursor
bool al_show_mouse_cursor(ALLEGRO_DISPLAY *display)
Make a mouse cursor visible in the given display.
Returns true if a mouse cursor is shown as a result of the call (or one already was visible), false otherwise.
See also: al_hide_mouse_cursor
al_grab_mouse
bool al_grab_mouse(ALLEGRO_DISPLAY *display)
Confine the mouse cursor to the given display. The mouse cursor can only be confined to one display at a time.
Returns true if successful, otherwise returns false. Do not assume that the cursor will remain confined until you call al_ungrab_mouse. It may lose the confined status at any time for other reasons.
Note: not yet implemented on Mac OS X.
See also: al_ungrab_mouse
al_ungrab_mouse
bool al_ungrab_mouse(void)
Stop confining the mouse cursor to any display belonging to the program.
Note: not yet implemented on Mac OS X.
See also: al_grab_mouse