We don't translate it away. The property does 2 things not available
in the pipe interface:
- It disables viewport clipping, so that window coordinates can pass
through untouched.
- It disables viewport transformation.
Our hardware is capable of both, however, some APIs are not.
Marek
On Wed, May 21, 2014 at 12:42 PM, Roland Scheidegger <srol...@vmware.com> wrote:
> On 05/21/2014 12:49 AM, Marek Olšák wrote:
>>
>> Hi,
>>
>> Could somebody from VMWare please review this patch? It's for st/nine
>> (open d3d9 state tracker).
>>
>> Thanks,
>>
>> Marek
>>
>> On Sat, May 17, 2014 at 1:20 AM, Automated rebase
>> <david.heidelber...@ixit.cz> wrote:
>>>
>>> From: Christoph Bumiller <e0425...@student.tuwien.ac.at>
>>>
>>> ---
>>> src/gallium/auxiliary/tgsi/tgsi_strings.c | 3 ++-
>>> src/gallium/auxiliary/tgsi/tgsi_ureg.c | 16 ++++++++++++++++
>>> src/gallium/auxiliary/tgsi/tgsi_ureg.h | 4 ++++
>>> src/gallium/docs/source/tgsi.rst | 9 +++++++++
>>> src/gallium/include/pipe/p_shader_tokens.h | 3 ++-
>>> 5 files changed, 33 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_strings.c
>>> b/src/gallium/auxiliary/tgsi/tgsi_strings.c
>>> index 5b6e47f..c3e7118 100644
>>> --- a/src/gallium/auxiliary/tgsi/tgsi_strings.c
>>> +++ b/src/gallium/auxiliary/tgsi/tgsi_strings.c
>>> @@ -120,7 +120,8 @@ const char *tgsi_property_names[TGSI_PROPERTY_COUNT]
>>> =
>>> "FS_COORD_PIXEL_CENTER",
>>> "FS_COLOR0_WRITES_ALL_CBUFS",
>>> "FS_DEPTH_LAYOUT",
>>> - "VS_PROHIBIT_UCPS"
>>> + "VS_PROHIBIT_UCPS",
>>> + "VS_POSITION_WINDOW_SPACE"
>>> };
>>>
>>> const char *tgsi_type_names[5] =
>>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_ureg.c
>>> b/src/gallium/auxiliary/tgsi/tgsi_ureg.c
>>> index 2bf93ee..bd0a3f7 100644
>>> --- a/src/gallium/auxiliary/tgsi/tgsi_ureg.c
>>> +++ b/src/gallium/auxiliary/tgsi/tgsi_ureg.c
>>> @@ -173,6 +173,7 @@ struct ureg_program
>>> unsigned char property_fs_coord_pixel_center; /* =
>>> TGSI_FS_COORD_PIXEL_CENTER_* */
>>> unsigned char property_fs_color0_writes_all_cbufs; /* =
>>> TGSI_FS_COLOR0_WRITES_ALL_CBUFS * */
>>> unsigned char property_fs_depth_layout; /* TGSI_FS_DEPTH_LAYOUT */
>>> + boolean property_vs_window_space_position; /*
>>> TGSI_VS_WINDOW_SPACE_POSITION */
>>>
>>> unsigned nr_addrs;
>>> unsigned nr_preds;
>>> @@ -331,6 +332,13 @@ ureg_property_fs_depth_layout(struct ureg_program
>>> *ureg,
>>> ureg->property_fs_depth_layout = fs_depth_layout;
>>> }
>>>
>>> +void
>>> +ureg_property_vs_window_space_position(struct ureg_program *ureg,
>>> + boolean vs_window_space_position)
>>> +{
>>> + ureg->property_vs_window_space_position = vs_window_space_position;
>>> +}
>>> +
>>> struct ureg_src
>>> ureg_DECL_fs_input_cyl_centroid(struct ureg_program *ureg,
>>> unsigned semantic_name,
>>> @@ -1508,6 +1516,14 @@ static void emit_decls( struct ureg_program *ureg
>>> )
>>> ureg->property_fs_depth_layout);
>>> }
>>>
>>> + if (ureg->property_vs_window_space_position) {
>>> + assert(ureg->processor == TGSI_PROCESSOR_VERTEX);
>>> +
>>> + emit_property(ureg,
>>> + TGSI_PROPERTY_VS_WINDOW_SPACE_POSITION,
>>> + ureg->property_vs_window_space_position);
>>> + }
>>> +
>>> if (ureg->processor == TGSI_PROCESSOR_VERTEX) {
>>> for (i = 0; i < UREG_MAX_INPUT; i++) {
>>> if (ureg->vs_inputs[i/32] & (1 << (i%32))) {
>>> diff --git a/src/gallium/auxiliary/tgsi/tgsi_ureg.h
>>> b/src/gallium/auxiliary/tgsi/tgsi_ureg.h
>>> index a0a50b7..28edea6 100644
>>> --- a/src/gallium/auxiliary/tgsi/tgsi_ureg.h
>>> +++ b/src/gallium/auxiliary/tgsi/tgsi_ureg.h
>>> @@ -184,6 +184,10 @@ void
>>> ureg_property_fs_depth_layout(struct ureg_program *ureg,
>>> unsigned fs_depth_layout);
>>>
>>> +void
>>> +ureg_property_vs_window_space_position(struct ureg_program *ureg,
>>> + boolean
>>> vs_window_space_position);
>>> +
>>>
>>>
>>> /***********************************************************************
>>> * Build shader declarations:
>>> diff --git a/src/gallium/docs/source/tgsi.rst
>>> b/src/gallium/docs/source/tgsi.rst
>>> index 9500b9d..2ca3c3b 100644
>>> --- a/src/gallium/docs/source/tgsi.rst
>>> +++ b/src/gallium/docs/source/tgsi.rst
>>> @@ -2848,6 +2848,15 @@ input primitive. Each invocation will have a
>>> different
>>> TGSI_SEMANTIC_INVOCATIONID system value set. If not specified, assumed
>>> to
>>> be 1.
>>>
>>> +VS_WINDOW_SPACE_POSITION
>>> +""""""""""""""""""""""""""
>>> +If this property is set on the vertex shader, the TGSI_SEMANTIC_POSITION
>>> output
>>> +is assumed to contain window space coordinates.
>>> +Division of X,Y,Z by W and the viewport transformation are disabled, and
>>> 1/W is
>>> +directly taken from the 4-th component of the shader output.
>>> +Naturally, clipping is not performed on window coordinates either.
>>> +The effect of this property is undefined if a geometry or tessellation
>>> shader
>>> +are in use.
>>>
>>> Texture Sampling and Texture Formats
>>> ------------------------------------
>>> diff --git a/src/gallium/include/pipe/p_shader_tokens.h
>>> b/src/gallium/include/pipe/p_shader_tokens.h
>>> index d095bd3..9261b79 100644
>>> --- a/src/gallium/include/pipe/p_shader_tokens.h
>>> +++ b/src/gallium/include/pipe/p_shader_tokens.h
>>> @@ -237,7 +237,8 @@ union tgsi_immediate_data
>>> #define TGSI_PROPERTY_FS_DEPTH_LAYOUT 6
>>> #define TGSI_PROPERTY_VS_PROHIBIT_UCPS 7
>>> #define TGSI_PROPERTY_GS_INVOCATIONS 8
>>> -#define TGSI_PROPERTY_COUNT 9
>>> +#define TGSI_PROPERTY_VS_WINDOW_SPACE_POSITION 9
>>> +#define TGSI_PROPERTY_COUNT 10
>>>
>>> struct tgsi_property {
>>> unsigned Type : 4; /**< TGSI_TOKEN_TYPE_PROPERTY */
>>> --
>
>
> I can't say I'm a big fan of it (I guess alternatively you could use a
> TGSI_SEMANTIC_POSITIONT output but that doesn't really make a difference
> neither).
> This was quite some d3d hack which doesn't really fit into a modern shader
> based world (of course, it doesn't work with d3d10 neither). So, the usual
> way to deal with this is to translate this away, since this was only used
> for old or simple stuff afaik (if it was complex you tend to not already
> know the screen space coords) noone is going to care if it runs at 1500 or
> 1520 fps anyway.
> But if you really think this is a must have and are going to use it in a
> public state tracker you probably have to implement a cap bit for it too,
> and be able to deal with drivers which can't handle it - it seems
> unreasonable to me to assume all drivers will handle it (hence you don't
> really save anything in the state tracker, you still need all the code
> translating it away anyway).
>
> Roland
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
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