Re: GDK-DirectFB Patches

[Denis Oliver Kropp <dok directfb org>]

Carl Worth wrote:
> On Wed, 5 Dec 2007 12:15:38 -0800, "Mike Emmel" wrote:
>> I've not come up with a general
>> way to interleave a Cairo context
>> with directfb calls. So depending on how you do things you can get
>> unexpected results.
> 
> Above we were talking about performance, right? And here you are
> talking about incorrect results, right? What's the cause of this? Is
> it that cairo-directfb is just broken?
> 
> For interleaving cairo and non-cairo rendering, cairo provides the
> cairo_surface_flush and cairo_surface_mark_dirty APIs. Does
> cairo-directfb implement those and does your application use them.


Thanks for the pointer. The cairo-directfb backend seems to do nothing
in these functions. I'm not sure what it's supposed to do. Should the
first accumulate a region to flip and the second actually flips?


static cairo_status_t
_cairo_directfb_surface_mark_dirty_rectangle (void *abstract_surface,
                                              int   x,
                                              int   y,
                                              int   width,
                                              int   height)
{
#if 0
    cairo_directfb_surface_t *surface = abstract_surface;

    D_DEBUG_AT (Cairo_DirectFB,
                "%s( surface=%p, x=%d, y=%d, width=%d, height=%d ).\n",
                __FUNCTION__, surface, x, y, width, height);
    if( !surface->dirty_region )
            surface->dirty_region = malloc(sizeof(DFBRegion));
    if (!dirty_region)
            return CAIRO_STATUS_NO_MEMORY;
#endif
    return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_directfb_surface_flush (void *abstract_surface)
{
#if 0
    cairo_directfb_surface_t *surface = abstract_surface;

    D_DEBUG_AT (Cairo_DirectFB,
                "%s( surface=%p ).\n", __FUNCTION__, surface);

    if (surface->surface != surface->buffer) {
        surface->surface->SetClip (surface->surface, NULL);
        surface->surface->SetBlittingFlags (surface->surface, DSBLIT_NOFX);
        surface->surface->Blit (surface->surface, surface->buffer, NULL, 0, 0);
    }
#endif
    return CAIRO_STATUS_SUCCESS;
}


No more ->surface and ->buffer exist, just ->dfbsurface.


typedef struct _cairo_directfb_surface {
    cairo_surface_t      base;
    cairo_format_t       format;
    IDirectFB           *dfb;
    int                 owner;
    IDirectFBSurface    *dfbsurface;
    /* color buffer */
    cairo_surface_t     *color;

    DFBRegion           *clips;
    int                  n_clips;
    DFBRegion           *dirty_region;
    int                  width;
    int                  height;
} cairo_directfb_surface_t;



BTW, with the recent state/clipping fixes to GDK-DirectFB, the rectangle
filling in cairo-directfb could be fixed, I did not check the BTS entries
to verify what was the problem with it.

-- 
Best regards,
  Denis Oliver Kropp

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