[Mesa-dev] [PATCH 2/5] gallium: increase the number of available stream output decls

[Roland Scheidegger]

Am 25.04.2013 19:44, schrieb Zack Rusin:
> ----- Original Message -----
>> Am 24.04.2013 00:58, schrieb Zack Rusin:
>>> There can be more stream output decls than shader outputs because
>>> individual components from them can be split and distributed
>>> among different so buffers.
>>>
>>> Signed-off-by: Zack Rusin <zackr at vmware.com>
>>> ---
>>>  src/gallium/include/pipe/p_state.h |    3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/src/gallium/include/pipe/p_state.h
>>> b/src/gallium/include/pipe/p_state.h
>>> index c0b2bcd..5830dff 100644
>>> --- a/src/gallium/include/pipe/p_state.h
>>> +++ b/src/gallium/include/pipe/p_state.h
>>> @@ -64,6 +64,7 @@ extern "C" {
>>>  #define PIPE_MAX_SHADER_RESOURCES 32
>>>  #define PIPE_MAX_TEXTURE_LEVELS   16
>>>  #define PIPE_MAX_SO_BUFFERS        4
>>> +#define PIPE_MAX_SO_OUTPUT_COMPONENT_COUNT 128
>>>  
>>>  
>>>  struct pipe_reference
>>> @@ -198,7 +199,7 @@ struct pipe_stream_output_info
>>>        unsigned num_components:3;  /** 1 to 4 */
>>>        unsigned output_buffer:3;   /**< 0 to PIPE_MAX_SO_BUFFERS */
>>>        unsigned dst_offset:16;     /**< offset into the buffer in dwords */
>>> -   } output[PIPE_MAX_SHADER_OUTPUTS];
>>> +   } output[PIPE_MAX_SO_BUFFERS * PIPE_MAX_SO_OUTPUT_COMPONENT_COUNT];
>>>  };
>>>  
>>>  
>>>
>>
>> Are you sure this isn't overkill, that is if you have multiple buffers
>> this really increases the total number of attributes you can output? I
>> thought this merely allows you to distribute the same number to
>> different buffers.
>> Also I'm not quite convinced with the 128 number. It looks like d3d10
>> has a limit of 64 components, and it seems like OpenGL would be happy
>> with that as well.
> 
> Yes, I'm sure.
> "The number of entries in the stream output declaration ( ranges from 0 to D3D11_SO_STREAM_COUNT * D3D11_SO_OUTPUT_COMPONENT_COUNT )"
> http://msdn.microsoft.com/en-US/library/windows/apps/ff476510
> D3D10 has a lower limit (64) but I didn't feel it was in our best interest to add something that we'll need to change in a few months again.

Ok that's fair enough if we can do the rest of stream output which d3d11
requires.

Roland