[Mesa-dev] [PATCH v2] swr: [rasterizer core] allow an OpenGL driver to specify halfz clipping

[Rowley, Timothy O]

SwrSetRastState shouldn’t be overriding what the caller passed in.  clip.h changes look good.

> On Nov 9, 2016, at 10:56 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> 
> With ARB_clip_control, GL may also do 0..1 depth clipping, not just
> -1..1. This removes clip's reliance on driver type. Instead we force
> halfz to on for DX driver types at the API layer.
> 
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
> 
> v1 -> v2: remove driverType from clip, set halfz at API layer
> 
> src/gallium/drivers/swr/rasterizer/core/api.cpp |  4 ++++
> src/gallium/drivers/swr/rasterizer/core/clip.h  | 13 ++++++-------
> src/gallium/drivers/swr/rasterizer/core/state.h |  1 +
> 3 files changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/src/gallium/drivers/swr/rasterizer/core/api.cpp b/src/gallium/drivers/swr/rasterizer/core/api.cpp
> index b1a426d..70bd6a8 100644
> --- a/src/gallium/drivers/swr/rasterizer/core/api.cpp
> +++ b/src/gallium/drivers/swr/rasterizer/core/api.cpp
> @@ -701,6 +701,10 @@ void SwrSetRastState(
>     API_STATE* pState = GetDrawState(pContext);
> 
>     memcpy(&pState->rastState, pRastState, sizeof(SWR_RASTSTATE));
> +    if (pContext->driverType == DX)
> +    {
> +        pState->rastState.clipHalfZ = 1;
> +    }
> }
> 
> void SwrSetViewports(
> diff --git a/src/gallium/drivers/swr/rasterizer/core/clip.h b/src/gallium/drivers/swr/rasterizer/core/clip.h
> index 43bc522..3d86b28 100644
> --- a/src/gallium/drivers/swr/rasterizer/core/clip.h
> +++ b/src/gallium/drivers/swr/rasterizer/core/clip.h
> @@ -63,7 +63,7 @@ void Clip(const float *pTriangle, const float *pAttribs, int numAttribs, float *
>           int *numVerts, float *pOutAttribs);
> 
> INLINE
> -void ComputeClipCodes(DRIVER_TYPE type, const API_STATE& state, const simdvector& vertex, simdscalar& clipCodes, simdscalari viewportIndexes)
> +void ComputeClipCodes(const API_STATE& state, const simdvector& vertex, simdscalar& clipCodes, simdscalari viewportIndexes)
> {
>     clipCodes = _simd_setzero_ps();
> 
> @@ -90,7 +90,7 @@ void ComputeClipCodes(DRIVER_TYPE type, const API_STATE& state, const simdvector
>     {
>         // FRUSTUM_NEAR
>         // DX clips depth [0..w], GL clips [-w..w]
> -        if (type == DX)
> +        if (state.rastState.clipHalfZ)
>         {
>             vRes = _simd_cmplt_ps(vertex.z, _simd_setzero_ps());
>         }
> @@ -135,7 +135,7 @@ class Clipper
> {
> public:
>     Clipper(uint32_t in_workerId, DRAW_CONTEXT* in_pDC) :
> -        workerId(in_workerId), driverType(in_pDC->pContext->driverType), pDC(in_pDC), state(GetApiState(in_pDC))
> +        workerId(in_workerId), pDC(in_pDC), state(GetApiState(in_pDC))
>     {
>         static_assert(NumVertsPerPrim >= 1 && NumVertsPerPrim <= 3, "Invalid NumVertsPerPrim");
>     }
> @@ -144,7 +144,7 @@ public:
>     {
>         for (uint32_t i = 0; i < NumVertsPerPrim; ++i)
>         {
> -            ::ComputeClipCodes(this->driverType, this->state, vertex[i], this->clipCodes[i], viewportIndexes);
> +            ::ComputeClipCodes(this->state, vertex[i], this->clipCodes[i], viewportIndexes);
>         }
>     }
> 
> @@ -640,7 +640,7 @@ private:
>         case FRUSTUM_BOTTOM:    t = ComputeInterpFactor(_simd_sub_ps(v1[3], v1[1]), _simd_sub_ps(v2[3], v2[1])); break;
>         case FRUSTUM_NEAR:      
>             // DX Znear plane is 0, GL is -w
> -            if (this->driverType == DX)
> +            if (this->state.rastState.clipHalfZ)
>             {
>                 t = ComputeInterpFactor(v1[2], v2[2]);
>             }
> @@ -708,7 +708,7 @@ private:
>         case FRUSTUM_RIGHT:     return _simd_cmple_ps(v[0], v[3]);
>         case FRUSTUM_TOP:       return _simd_cmpge_ps(v[1], _simd_mul_ps(v[3], _simd_set1_ps(-1.0f)));
>         case FRUSTUM_BOTTOM:    return _simd_cmple_ps(v[1], v[3]);
> -        case FRUSTUM_NEAR:      return _simd_cmpge_ps(v[2], this->driverType == DX ? _simd_setzero_ps() : _simd_mul_ps(v[3], _simd_set1_ps(-1.0f)));
> +        case FRUSTUM_NEAR:      return _simd_cmpge_ps(v[2], this->state.rastState.clipHalfZ ? _simd_setzero_ps() : _simd_mul_ps(v[3], _simd_set1_ps(-1.0f)));
>         case FRUSTUM_FAR:       return _simd_cmple_ps(v[2], v[3]);
>         default:
>             SWR_ASSERT(false, "invalid clipping plane: %d", ClippingPlane);
> @@ -942,7 +942,6 @@ private:
>     }
> 
>     const uint32_t workerId{ 0 };
> -    const DRIVER_TYPE driverType{ DX };
>     DRAW_CONTEXT* pDC{ nullptr };
>     const API_STATE& state;
>     simdscalar clipCodes[NumVertsPerPrim];
> diff --git a/src/gallium/drivers/swr/rasterizer/core/state.h b/src/gallium/drivers/swr/rasterizer/core/state.h
> index 93e4565..5ee12e8 100644
> --- a/src/gallium/drivers/swr/rasterizer/core/state.h
> +++ b/src/gallium/drivers/swr/rasterizer/core/state.h
> @@ -932,6 +932,7 @@ struct SWR_RASTSTATE
>     uint32_t frontWinding           : 1;
>     uint32_t scissorEnable          : 1;
>     uint32_t depthClipEnable        : 1;
> +    uint32_t clipHalfZ              : 1;
>     uint32_t pointParam             : 1;
>     uint32_t pointSpriteEnable      : 1;
>     uint32_t pointSpriteTopOrigin   : 1;
> -- 
> 2.7.3
>