[Mesa-dev] [PATCH 38/40] i965: Consider all viewports before enabling guardband clipping

[Kenneth Graunke]

On 01/10/2014 05:40 PM, Ian Romanick wrote:
> From: Ian Romanick <ian.d.romanick at intel.com>
> 
> Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
> ---
>  src/mesa/drivers/dri/i965/gen6_clip_state.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/gen6_clip_state.c b/src/mesa/drivers/dri/i965/gen6_clip_state.c
> index 3499e37..ed7afd7 100644
> --- a/src/mesa/drivers/dri/i965/gen6_clip_state.c
> +++ b/src/mesa/drivers/dri/i965/gen6_clip_state.c
> @@ -96,11 +96,15 @@ upload_clip_state(struct brw_context *brw)
>     dw2 |= (ctx->Transform.ClipPlanesEnabled <<
>             GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT);
>  
> -   if (ctx->ViewportArray[0].X == 0 &&
> -       ctx->ViewportArray[0].Y == 0 &&
> -       ctx->ViewportArray[0].Width == (float) fb->Width &&
> -       ctx->ViewportArray[0].Height == (float) fb->Height) {
> -      dw2 |= GEN6_CLIP_GB_TEST;
> +   dw2 |= GEN6_CLIP_GB_TEST;
> +   for (unsigned i = 0; i < ctx->Const.MaxViewports; i++) {

Don't you want to check for actually enabled viewports here?  I'm not
sure what data the others get, but I imagine it's fairly bogus and thus
would result in guardband clipping always getting disabled.

> +      if (ctx->ViewportArray[i].X != 0 ||
> +          ctx->ViewportArray[i].Y != 0 ||
> +          ctx->ViewportArray[i].Width != (float) fb->Width ||
> +          ctx->ViewportArray[i].Height != (float) fb->Height) {
> +         dw2 &= ~GEN6_CLIP_GB_TEST;
> +         break;
> +      }
>     }
>  
>     /* BRW_NEW_RASTERIZER_DISCARD */
>