[Mesa-dev] [PATCH 7/9] softpipe: don't use 3-component formats

[Brian Paul]

On 08/24/2015 06:59 PM, Marek Olšák wrote:
> On Tue, Aug 25, 2015 at 1:04 AM, Brian Paul <brianp at vmware.com> wrote:
>> Mesa and gallium don't have a complete set of matching 3-component
>> texture formats.  For example, 8-bit sRGB unorm.  To fully support
>> the GL_ARB_copy_image extension we need to have support for all of
>> these formats: RGB8_UNORM, RGB8_SNORM, RGB8_SRGB, RGB8_UINT, and
>> RGB8_SINT using the same component order.  Since we don't have that,
>> disable the 3-component formats for now.
>> ---
>>   src/gallium/drivers/softpipe/sp_screen.c | 25 +++++++++++++++++++++++++
>>   1 file changed, 25 insertions(+)
>>
>> diff --git a/src/gallium/drivers/softpipe/sp_screen.c b/src/gallium/drivers/softpipe/sp_screen.c
>> index aeef8e6..24d79f1 100644
>> --- a/src/gallium/drivers/softpipe/sp_screen.c
>> +++ b/src/gallium/drivers/softpipe/sp_screen.c
>> @@ -360,6 +360,31 @@ softpipe_is_format_supported( struct pipe_screen *screen,
>>         return FALSE;
>>      }
>>
>> +   if ((bind & (PIPE_BIND_RENDER_TARGET | PIPE_BIND_SAMPLER_VIEW)) &&
>> +       ((bind & PIPE_BIND_DISPLAY_TARGET) == 0)) {
>> +      if (format == PIPE_FORMAT_R8G8B8_UINT ||
>> +          format == PIPE_FORMAT_R8G8B8_SINT ||
>> +          format == PIPE_FORMAT_R8G8B8_UNORM ||
>> +          format == PIPE_FORMAT_R16G16B16_UINT ||
>> +          format == PIPE_FORMAT_R16G16B16_SINT ||
>> +          format == PIPE_FORMAT_R16G16B16_UNORM ||
>> +          format == PIPE_FORMAT_R16G16B16_FLOAT ||
>> +          format == PIPE_FORMAT_R32G32B32_UINT ||
>> +          format == PIPE_FORMAT_R32G32B32_SINT ||
>> +          format == PIPE_FORMAT_R32G32B32_UNORM ||
>> +          format == PIPE_FORMAT_R32G32B32_FLOAT) {
>
> For simpler code and keeping TBO support:
>
> desc->is_array && desc->nr_channels == 3 && target != PIPE_BUFFER
>
> where desc = util_format_description(format)

Formats such as PIPE_FORMAT_B8G8R8X8_UNORM report nr_channels=4.  One 
also has to count the number of non-UTIL_FORMAT_TYPE_VOID channel types. 
  I had tried that but it didn't work out and I didn't dig deeper into it.

-Brian