[PATCH] egl, wayland: RGB565 format support on Back-buffer

[Jon A. Cruz]

On 02/06/2015 03:50 PM, Bryce Harrington wrote:
> On Fri, Feb 06, 2015 at 12:29:02PM -0800, Jon A. Cruz wrote:
>>
>> My initial concern with this is that it changes from one hardcoding to
>> two hardcodings. Is 565 the only other format that will need to be
>> supported? Could XRGB888 or others also be needed?
>>
>> If this needs changing it might be good to be sure it is comprehensive.
> 
> Yes, that'd be nice, but couldn't those other formats be added as their
> need crops up?
>  


If it were started as a solution using case, then yes. But by using the
conditional operator the later changes would be more significant and
allow for bugs to creep in.

Also I do see a list of three formats set for some bitmask elsewhere.
This then hints that the code cares about at least those three formats.


>> On 02/03/2015 02:52 PM, Dongwon Kim wrote:
>>> In current code, color format is always hardcoded to __DRI_IMAGE_FORMAT_ARGB8888
>>> when buffer or DRI image is allocated in function calls, get_back_bo and dri2_get_buffers,
>>> regardless of current target's color format. This problem may leads to incorrect render
>>> pitch calculation, which eventually ends up with wrong offset of pixels in the frame buffer
>>> when the image is in different color format from dri surf's, especially with different bpp.
>>> (e.g. 16bpp)
>>>
>>> Attached code patch simply adds RGB565 case to two functions noted above to resolve
>>> the issue.
>>>
>>> Signed-off-by: Vivek Kasireddy <vivek.kasireddy at intel.com>
>>> Signed-off-by: Dongwon Kim <dongwon.kim at intel.com>
>>> ---
>>>  src/egl/drivers/dri2/platform_wayland.c |   10 ++++++++--
>>>  1 file changed, 8 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c
>>> index 3c34e07..78761e2 100644
>>> --- a/src/egl/drivers/dri2/platform_wayland.c
>>> +++ b/src/egl/drivers/dri2/platform_wayland.c
>>> @@ -293,6 +293,11 @@ get_back_bo(struct dri2_egl_surface *dri2_surf)
>>>        dri2_egl_display(dri2_surf->base.Resource.Display);
>>>     int i;
>>>  
>>> +   /* currently supports two DRI image formats, __DRI_IMAGE_FORMAT_RGB565 or __DRI_IMAGE_FORMAT_ARGB8888,
>>> +    * one of which is selected depending on dri surface format */
>>> +   const unsigned int dri_image_format =
>>> +        (dri2_surf->format == WL_DRM_FORMAT_RGB565) ? __DRI_IMAGE_FORMAT_RGB565 : __DRI_IMAGE_FORMAT_ARGB8888;
>>> +
>>>     /* We always want to throttle to some event (either a frame callback or
>>>      * a sync request) after the commit so that we can be sure the
>>>      * compositor has had a chance to handle it and send us a release event
>>> @@ -322,7 +327,7 @@ get_back_bo(struct dri2_egl_surface *dri2_surf)
>>>           dri2_dpy->image->createImage(dri2_dpy->dri_screen,
>>>                                        dri2_surf->base.Width,
>>>                                        dri2_surf->base.Height,
>>> -                                      __DRI_IMAGE_FORMAT_ARGB8888,
>>> +                                      dri_image_format,
>>>                                        __DRI_IMAGE_USE_SHARE,
>>>                                        NULL);
>>>        dri2_surf->back->age = 0;
>>> @@ -462,9 +467,10 @@ dri2_wl_get_buffers(__DRIdrawable * driDrawable,
>>>                      unsigned int *attachments, int count,
>>>                      int *out_count, void *loaderPrivate)
>>>  {
>>> +   struct dri2_egl_surface *dri2_surf = loaderPrivate;
>>>     unsigned int *attachments_with_format;
>>>     __DRIbuffer *buffer;
>>> -   const unsigned int format = 32;
>>> +   const unsigned int format = (dri2_surf->format == WL_DRM_FORMAT_RGB565) ? 16 : 32;
>>>     int i;
>>>  
>>>     attachments_with_format = calloc(count, 2 * sizeof(unsigned int));
>>>
>> _______________________________________________
>> wayland-devel mailing list
>> wayland-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/wayland-devel

-- 
Jon A. Cruz - Senior Open Source Developer
Samsung Open Source Group
jonc at osg.samsung.com