[Mesa-dev] [PATCH 8/8] nine: allow fragment shader POSITION and FACE to be system values

[Axel Davy]

On 08/01/2016 02:29, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
>
> ---
>   src/gallium/state_trackers/nine/nine_ff.c     | 10 +++++-
>   src/gallium/state_trackers/nine/nine_shader.c | 48 +++++++++++++++++++++------
>   2 files changed, 46 insertions(+), 12 deletions(-)
>
> diff --git a/src/gallium/state_trackers/nine/nine_ff.c b/src/gallium/state_trackers/nine/nine_ff.c
> index fe26086..0feaeab 100644
> --- a/src/gallium/state_trackers/nine/nine_ff.c
> +++ b/src/gallium/state_trackers/nine/nine_ff.c
> @@ -1391,7 +1391,15 @@ nine_ff_build_ps(struct NineDevice9 *device, struct nine_ff_ps_key *key)
>       /* Fog.
>        */
>       if (key->fog_mode) {
> -        struct ureg_src vPos = ureg_DECL_fs_input(ureg, TGSI_SEMANTIC_POSITION, 0, TGSI_INTERPOLATE_LINEAR);
> +        struct ureg_src vPos;
> +        if (device->screen->get_param(device->screen,
> +                                      PIPE_CAP_TGSI_FS_POSITION_IS_SYSVAL)) {
> +            vPos = ureg_DECL_system_value(ureg, TGSI_SEMANTIC_POSITION, 0);
> +        } else {
> +            vPos = ureg_DECL_fs_input(ureg, TGSI_SEMANTIC_POSITION, 0,
> +                                      TGSI_INTERPOLATE_LINEAR);
> +        }
> +
>           struct ureg_dst rFog = ureg_writemask(ps.rTmp, TGSI_WRITEMASK_X);
>           if (key->fog_mode == D3DFOG_EXP) {
>               ureg_MUL(ureg, rFog, _ZZZZ(vPos), _ZZZZ(_CONST(22)));
> diff --git a/src/gallium/state_trackers/nine/nine_shader.c b/src/gallium/state_trackers/nine/nine_shader.c
> index 28f2787..311897d 100644
> --- a/src/gallium/state_trackers/nine/nine_shader.c
> +++ b/src/gallium/state_trackers/nine/nine_shader.c
> @@ -462,6 +462,8 @@ struct shader_translator
>       boolean lower_preds;
>       boolean want_texcoord;
>       boolean shift_wpos;
> +    boolean wpos_is_sysval;
> +    boolean face_is_sysval_integer;
>       unsigned texcoord_sn;
>   
>       struct sm1_instruction insn; /* current instruction */
> @@ -945,10 +947,16 @@ tx_src_param(struct shader_translator *tx, const struct sm1_src_param *param)
>       case D3DSPR_MISCTYPE:
>           switch (param->idx) {
>           case D3DSMO_POSITION:
> -           if (ureg_src_is_undef(tx->regs.vPos))
> -               tx->regs.vPos = ureg_DECL_fs_input(ureg,
> -                                                  TGSI_SEMANTIC_POSITION, 0,
> -                                                  TGSI_INTERPOLATE_LINEAR);
> +           if (ureg_src_is_undef(tx->regs.vPos)) {
> +              if (tx->wpos_is_sysval) {
> +                  tx->regs.vPos =
> +                      ureg_DECL_system_value(ureg, TGSI_SEMANTIC_POSITION, 0);
> +              } else {
> +                  tx->regs.vPos =
> +                      ureg_DECL_fs_input(ureg, TGSI_SEMANTIC_POSITION, 0,
> +                                         TGSI_INTERPOLATE_LINEAR);
> +              }
> +           }
>              if (tx->shift_wpos) {
>                  /* TODO: do this only once */
>                  struct ureg_dst wpos = tx_scratch(tx);
> @@ -961,9 +969,20 @@ tx_src_param(struct shader_translator *tx, const struct sm1_src_param *param)
>              break;
>           case D3DSMO_FACE:
>              if (ureg_src_is_undef(tx->regs.vFace)) {
> -               tx->regs.vFace = ureg_DECL_fs_input(ureg,
> -                                                   TGSI_SEMANTIC_FACE, 0,
> -                                                   TGSI_INTERPOLATE_CONSTANT);
> +               if (tx->face_is_sysval_integer) {
> +                   tmp = tx_scratch(tx);
> +                   tx->regs.vFace =
> +                       ureg_DECL_system_value(ureg, TGSI_SEMANTIC_FACE, 0);
> +
> +                   /* convert bool to float */
> +                   ureg_UCMP(ureg, tmp, ureg_scalar(tx->regs.vFace, TGSI_SWIZZLE_X),
> +                             ureg_imm1f(ureg, 1), ureg_imm1f(ureg, 0));

This looks wrong. It should be -1.0 for the backface and 1.0 for the 
frontface.

> +                   tx->regs.vFace = ureg_src(tmp);
> +               } else {
> +                   tx->regs.vFace = ureg_DECL_fs_input(ureg,
> +                                                       TGSI_SEMANTIC_FACE, 0,
> +                                                       TGSI_INTERPOLATE_CONSTANT);
> +               }
>                  tx->regs.vFace = ureg_scalar(tx->regs.vFace, TGSI_SWIZZLE_X);
>              }
>              src = tx->regs.vFace;
> @@ -3259,10 +3278,15 @@ shader_add_ps_fog_stage(struct shader_translator *tx, struct ureg_src src_col)
>           return;
>       }
>   
> -    if (tx->info->fog_mode != D3DFOG_NONE)
> -        depth = ureg_scalar(ureg_DECL_fs_input(ureg, TGSI_SEMANTIC_POSITION, 0,
> -                                              TGSI_INTERPOLATE_LINEAR),
> -                                              TGSI_SWIZZLE_Z);
> +    if (tx->info->fog_mode != D3DFOG_NONE) {
> +        if (tx->wpos_is_sysval) {
> +            depth = ureg_DECL_system_value(ureg, TGSI_SEMANTIC_POSITION, 0);
> +        } else {
> +            depth = ureg_DECL_fs_input(ureg, TGSI_SEMANTIC_POSITION, 0,
> +                                       TGSI_INTERPOLATE_LINEAR);
> +        }
> +        depth = ureg_scalar(depth, TGSI_SWIZZLE_Z);
> +    }
>   
>       nine_info_mark_const_f_used(tx->info, 33);
>       fog_color = NINE_CONSTANT_SRC(32);
> @@ -3344,6 +3368,8 @@ nine_translate_shader(struct NineDevice9 *device, struct nine_shader_info *info)
>       tx->shift_wpos = !GET_CAP(TGSI_FS_COORD_PIXEL_CENTER_INTEGER);
>       tx->texcoord_sn = tx->want_texcoord ?
>           TGSI_SEMANTIC_TEXCOORD : TGSI_SEMANTIC_GENERIC;
> +    tx->wpos_is_sysval = GET_CAP(TGSI_FS_POSITION_IS_SYSVAL);
> +    tx->face_is_sysval_integer = GET_CAP(TGSI_FS_FACE_IS_INTEGER_SYSVAL);
>   
>       if (IS_VS) {
>           tx->num_constf_allowed = NINE_MAX_CONST_F;