[Mesa-dev] [PATCH] gallium: move clear paths from rgba to a pointer to a color union

[Roland Scheidegger]

Am 15.09.2011 19:11, schrieb Dave Airlie:
>>>
>>> This moves the gallium interface for clears from using a pointer to 4 floats
>>> to a pointer to a union of float/unsigned/int values. This is step one
>>> in allowing integer clears. I've tried to build as many drivers/pieces
>>> as I could, but I think I missed a couple, (vega for instance seems to
>>> need a bit more work).
>>
>>> diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
>>> index 49c12ec..b2d5f95 100644
>>> --- a/src/gallium/include/pipe/p_context.h
>>> +++ b/src/gallium/include/pipe/p_context.h
>>> @@ -63,7 +63,7 @@ struct pipe_vertex_element;
>>>  struct pipe_video_buffer;
>>>  struct pipe_video_decoder;
>>>  struct pipe_viewport_state;
>>> -
>>> +union pipe_color_union;
>>>
>>>  /**
>>>   * Gallium rendering context.  Basically:
>>> @@ -281,23 +281,23 @@ struct pipe_context {
>>>      * The entire buffers are cleared (no scissor, no colormask, etc).
>>>      *
>>>      * \param buffers  bitfield of PIPE_CLEAR_* values.
>>> -    * \param rgba  pointer to an array of one float for each of r, g, b, a.
>>> +    * \param color  pointer to a union of fiu array for each of r, g, b, a.
>>>      * \param depth  depth clear value in [0,1].
>>>      * \param stencil  stencil clear value
>>>      */
>>>     void (*clear)(struct pipe_context *pipe,
>>>                   unsigned buffers,
>>> -                 const float *rgba,
>>> +                 const union pipe_color_union *color,
>>>                   double depth,
>>>                   unsigned stencil);
>>>
>>>     /**
>>>      * Clear a color rendertarget surface.
>>> -    * \param rgba  pointer to an array of one float for each of r, g, b, a.
>>> +    * \param color  pointer to an union of fiu array for each of r, g, b, a.
>>>      */
>>>     void (*clear_render_target)(struct pipe_context *pipe,
>>>                                 struct pipe_surface *dst,
>>> -                               const float *rgba,
>>> +                               const union pipe_color_union *color,
>>>                                 unsigned dstx, unsigned dsty,
>>>                                 unsigned width, unsigned height);
>>>
>>
>> Hmm is it really necessary to change the clear function?
>> This is sort of a legacy clear, and neither OpenGL nor d3d9(*) allow you
>> to use anything but floats when specifying clear color.
>> (Yes I know mesa / mesa state tracker currently use clear and not
>> clear_render_target/clear_depth_stencil even for the glClearBufferxx
>> functions right now.)
> 
> You should know better by now than to claim GL can't do something
> stupid or insane.
> 
> EXT_gpu_shader4 allows this, I even fixed all the mesa entry points last week.
> 
> glClearColorIiEXT

Ah I see it's part of EXT_texture_integer actually. Ok I'm convinced :-).
It isn't actually really stupid or insane I guess, I just thought the
main reason for the ClearBufferxx funcs was because you couldn't clear
int buffers otherwise.

Roland