[Mesa-dev] [PATCH 6/7] i965: add functional changes for AMD_depth_clamp_separate

[Ian Romanick]

On 08/21/2018 05:02 PM, Sagar Ghuge wrote:
> Gen >= 9 have ability to control clamping of depth values separately at
> near and far plane.
> 
> z_w is clamped to the range [min(n,f), 0] if clamping at near plane is
> enabled, [0, max(n,f)] if clamping at far plane is enabled and [min(n,f)
> max(n,f)] if clamping at both plane is enabled.
> 
> Signed-off-by: Sagar Ghuge <sagar.ghuge at intel.com>
> ---
>  src/mesa/drivers/dri/i965/genX_state_upload.c | 23 +++++++++++++++----
>  1 file changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/genX_state_upload.c b/src/mesa/drivers/dri/i965/genX_state_upload.c
> index dc54cb67af..4e978bed91 100644
> --- a/src/mesa/drivers/dri/i965/genX_state_upload.c
> +++ b/src/mesa/drivers/dri/i965/genX_state_upload.c
> @@ -2343,7 +2343,13 @@ genX(upload_cc_viewport)(struct brw_context *brw)
>        if (ctx->Transform.DepthClampNear && ctx->Transform.DepthClampFar) {
>           ccv.MinimumDepth = MIN2(vp->Near, vp->Far);
>           ccv.MaximumDepth = MAX2(vp->Near, vp->Far);
> -      } else {
> +      } else if (ctx->Transform.DepthClampNear) {
> +         ccv.MinimumDepth = MIN2(vp->Near, vp->Far);
> +         ccv.MaximumDepth = 0.0;
> +      } else if (ctx->Transform.DepthClampFar) {
> +         ccv.MinimumDepth = 0.0;
> +         ccv.MaximumDepth = MAX2(vp->Near, vp->Far);
> +      }else {
          ^
Missing space here.

With that fixed, this patch is

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

>           ccv.MinimumDepth = 0.0;
>           ccv.MaximumDepth = 1.0;
>        }
> @@ -4607,16 +4613,23 @@ genX(upload_raster)(struct brw_context *brw)
>        raster.ScissorRectangleEnable = ctx->Scissor.EnableFlags;
>  
>        /* _NEW_TRANSFORM */
> +#if GEN_GEN < 9
>        if (!(ctx->Transform.DepthClampNear &&
>              ctx->Transform.DepthClampFar)) {
> -#if GEN_GEN >= 9
> -         raster.ViewportZFarClipTestEnable = true;
> -         raster.ViewportZNearClipTestEnable = true;
> -#else
>           raster.ViewportZClipTestEnable = true;
> +      }
>  #endif
> +
> +#if GEN_GEN >= 9
> +      if (!ctx->Transform.DepthClampNear) {
> +         raster.ViewportZNearClipTestEnable = true;
>        }

If the condition and the body of an if-statement are each a single text
line, it's okay to omit the { }.  If either the condition or the single
statement of the body are long enough to require line-wrapping, we still
require the { } because it improves readability.

You don't need to change this here.  I just thought I'd let you know for
future reference.  It's "coder's preference." :)

>  
> +      if (!ctx->Transform.DepthClampFar) {
> +         raster.ViewportZFarClipTestEnable = true;
> +      }
> +#endif
> +
>        /* BRW_NEW_CONSERVATIVE_RASTERIZATION */
>  #if GEN_GEN >= 9
>        raster.ConservativeRasterizationEnable =
>