Re: cursor maddnes and a solution

["Antonino A. Daplas" <adaplas@gmail.com>]

Jon Smirl wrote:
> On 8/10/05, Andrey Volkov <avolkov@varma-el.com> wrote:
>>
>> Jon Smirl wrote:
>>> On 8/10/05, Antonino A. Daplas <adaplas@gmail.com> wrote:
>>>
>>>> struct fb_cursor_ops {
>>>>        int (*cursor_move)(int x, int y);
>>>>        int (*cursor_show)(int show);
>>>>        int (*cursor_load_image)(u32 *image, int width, int height);
>>>>        int (*cursor_load_color)(struct fb_cmap *cmap);
>>>>        int (*cursor_set_size)(int width, int height);
>>>>        int (*cursor_capabilities)(int set, int caps);
>>>> };
>>>
>>> Doen't fb already support an image format with embedded color map? Can
>>> we use it and merge:
>>>
>>>>        int (*cursor_load_image)(u32 *image, int width, int height);
>>>>        int (*cursor_load_color)(struct fb_cmap *cmap);

Yes, we can do that.
 
>>>
>>> The size can also be computed from the image so the size call can be eliminated.
>>>
>> You are omit hwd cursor size problem - very few (possible no one)
>> graphics chips could support cursor with any size. Usually they support
>> 32x32/64x64 pixels cursors only. For kernel fb its have not meaning,
>> 'cause we always could fallback to the soft_cursor (in the fbcon or
>> directly in a driver), BUT what to do with such crazy user who will wish
>> to use, ex. 100x100 pix cursor in user space?
> 

If cursor_capabilities() is called, it should return the maximum
dimensions supported by the hardware.  

Meaning, we have to change it to:

int (*cursor_capabilities)(int set, struct fb_cursor_caps *caps);

so it passes struct fb_cursor_caps *caps instead of int caps.

Of course, if user is so crazy that he/she insists on using a 100x100 cursor
image, the kernel should return an error and, as Jon said, fallback to
a software implementation

Tony 


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