clear mouse pointer of current window/screen

[jotd]

I have a game where mouse pointer subsists from workbench


How can I get the active window so I can call ClearPointer on that?


asm, C, doesn't matter.

[thomas]

IntuitionBase->ActiveWindow

But that's not the right way. You should open your own window on your own screen, make that active and set its pointer.

BTW, ClearPointer returns the pointer to normal, so if you currently see the Workbench pointer, ClearPointer won't change that.

To hide the mouse pointer you have to allocate IIRC 4 bytes of Chip memory and give that to SetPointer. Thinking about it, it can also be 12 bytes. Two words for x/y coordinates, two words for a 1x1 pixel pointer with two bitplanes and another two words to end the sprite chain.

[jotd]

Originally Posted by thomas

IntuitionBase->ActiveWindow

But that's not the right way. You should open your own window on your own screen, make that active and set its pointer.

I know but I'm patching a game that doesn't do that.


With your advice I coded that asm piece and it works, so thanks. Dropping it here for people who're interested.

    INCLUDE    exec/exec.i
    INCLUDE    intuition/intuitionbase.i
    INCLUDE    lvo/exec.i
    INCLUDE    lvo/intuition.i


zap_pointer:
    movem.l    d0-d3/a0-a2/a6,-(a7)
    move.l    4.W,a6
    move.l    #MEMF_CHIP|MEMF_CLEAR,d1
    move.l    #12,d0
    jsr    (_LVOAllocMem,a6)
    move.l    d0,a2        ; save for later
    
    lea    (_intname,pc),a1
    jsr    (_LVOOldOpenLibrary,a6)
    move.l    d0,a6
    move.l    ib_ActiveWindow(a6),a0
    move.l    a2,a1
    moveq    #1,d0
    moveq    #1,d1
    moveq    #0,d2
    moveq    #0,d3
    jsr    _LVOSetPointer(a6)
    
    movem.l    (a7)+,d0-d3/a0-a2/a6
    rts
_intname
    dc.b    "intuition.library",0

[Photon]

Can SetPointer be used for a Screen somehow? ClearPointer works with ActiveWindow=0, but not SetPointer.

Edit: Doesn't seem so.

If only I could nudge the pointer down when I create my screen! I've tried to displace the screen instead, but the pointer is glued to screen's 0,0 on creation (and no way to create a screen with a custom pointer).

I realize of course that mouse movement is central to the OS, deep within an interrupt on the mouse port.

It's just that sometimes you want to show a screen for presentation, and then the pointer distracts (and you may have use of those colors).

[thomas]

You could call GetPrefs, make a copy of it, clear the pointer data and call SetPrefs.

On exit call SetPrefs with the original prefs to restore the pointer.

This the 1.3 way of setting preferences. I am not sure if it plays well with settings set by IPrefs.

Also if the user uses Amiga-M keys to return to the Workbench screen while your game is still running, he would not see a pointer there, too.

The best way is always to open Screen + Window together. A screen alone is of no use.

[Thomas Richter]

Originally Posted by Photon

Can SetPointer be used for a Screen somehow?

Not as such, but you rarely have a bare screen since a screen does not receive any data from intuition. It is just a canvas on which you can put windows. You should place a backdrop borderless window on the screen - the result looks the same, but with this window you can interact through intuition.

[Thomas Richter]

Originally Posted by thomas

You could call GetPrefs, make a copy of it, clear the pointer data and call SetPrefs.

Actually, I would not recommend that. It means that the mouse pointer goes away for every window that does not define its own pointer, and this is quite intrusive (not to say utterly confusing).