[Mesa-dev] [PATCH v2 3/7] mesa: Add support for AMD_depth_clamp_separate

Sagar Ghuge sagar.ghuge at intel.com
Thu Aug 23 00:14:03 UTC 2018


On 08/22/2018 04:31 PM, Marek Olšák wrote:
> On Wed, Aug 22, 2018 at 5:52 PM Sagar Ghuge <sagar.ghuge at intel.com> wrote:
>>
>> Enable _mesa_PushAttrib() and _mesa_PopAttrib() to handle
>> GL_DEPTH_CLAMP_NEAR_AMD and GL_DEPTH_CLAMP_FAR_AMD tokens.
>>
>> Remove DepthClamp, because DepthClampNear + DepthClampFar replaces it,
>> as suggested by Marek Olsak.
>>
>> Driver that enables AMD_depth_clamp_separate will only ever look at
>> DepthClampNear and DepthClampFar, as suggested by Ian Romanick.
>>
>> v2: 1) Remove unnecessary parentheses (Marek Olsak)
>>     2) if AMD_depth_clamp_separate is unsupported, TEST_AND_UPDATE
>>        GL_DEPTH_CLAMP only (Marek Olsak)
>>     3) Clamp against near and far plane separately (Marek Olsak)
>>     4) Clip point separately for near and far Z clipping plane (Marek
>>        Olsak)
>>
>> Signed-off-by: Sagar Ghuge <sagar.ghuge at intel.com>
>> ---
>>  src/mesa/drivers/dri/i965/genX_state_upload.c | 11 ++--
>>  src/mesa/main/attrib.c                        | 40 +++++++++++---
>>  src/mesa/main/enable.c                        |  9 ++-
>>  src/mesa/main/get.c                           |  4 ++
>>  src/mesa/main/get_hash_params.py              |  2 +-
>>  src/mesa/main/mtypes.h                        |  1 -
>>  src/mesa/main/rastpos.c                       | 55 ++++++++++++++++---
>>  src/mesa/state_tracker/st_atom_rasterizer.c   |  3 +-
>>  src/mesa/state_tracker/st_cb_drawpixels.c     |  3 +-
>>  src/mesa/swrast/s_span.c                      |  2 +-
>>  src/mesa/tnl/t_vb_program.c                   |  6 +-
>>  src/mesa/tnl/t_vb_vertex.c                    |  8 ++-
>>  12 files changed, 111 insertions(+), 33 deletions(-)
>>
>> diff --git a/src/mesa/drivers/dri/i965/genX_state_upload.c b/src/mesa/drivers/dri/i965/genX_state_upload.c
>> index c051848985..dc54cb67af 100644
>> --- a/src/mesa/drivers/dri/i965/genX_state_upload.c
>> +++ b/src/mesa/drivers/dri/i965/genX_state_upload.c
>> @@ -1399,7 +1399,8 @@ genX(upload_clip_state)(struct brw_context *brw)
>>        clip.ScreenSpaceViewportYMax = 1;
>>
>>        clip.ViewportXYClipTestEnable = true;
>> -      clip.ViewportZClipTestEnable = !ctx->Transform.DepthClamp;
>> +      clip.ViewportZClipTestEnable = !(ctx->Transform.DepthClampNear &&
>> +                                       ctx->Transform.DepthClampFar);
>>
>>        /* _NEW_TRANSFORM */
>>        if (GEN_GEN == 5 || GEN_IS_G4X) {
>> @@ -1493,7 +1494,8 @@ genX(upload_clip_state)(struct brw_context *brw)
>>        clip.UserClipDistanceCullTestEnableBitmask =
>>           brw_vue_prog_data(brw->vs.base.prog_data)->cull_distance_mask;
>>
>> -      clip.ViewportZClipTestEnable = !ctx->Transform.DepthClamp;
>> +      clip.ViewportZClipTestEnable = !(ctx->Transform.DepthClampNear &&
>> +                                       ctx->Transform.DepthClampFar);
>>  #endif
>>
>>        /* _NEW_LIGHT */
>> @@ -2338,7 +2340,7 @@ genX(upload_cc_viewport)(struct brw_context *brw)
>>     for (unsigned i = 0; i < viewport_count; i++) {
>>        /* _NEW_VIEWPORT | _NEW_TRANSFORM */
>>        const struct gl_viewport_attrib *vp = &ctx->ViewportArray[i];
>> -      if (ctx->Transform.DepthClamp) {
>> +      if (ctx->Transform.DepthClampNear && ctx->Transform.DepthClampFar) {
>>           ccv.MinimumDepth = MIN2(vp->Near, vp->Far);
>>           ccv.MaximumDepth = MAX2(vp->Near, vp->Far);
>>        } else {
>> @@ -4605,7 +4607,8 @@ genX(upload_raster)(struct brw_context *brw)
>>        raster.ScissorRectangleEnable = ctx->Scissor.EnableFlags;
>>
>>        /* _NEW_TRANSFORM */
>> -      if (!ctx->Transform.DepthClamp) {
>> +      if (!(ctx->Transform.DepthClampNear &&
>> +            ctx->Transform.DepthClampFar)) {
>>  #if GEN_GEN >= 9
>>           raster.ViewportZFarClipTestEnable = true;
>>           raster.ViewportZNearClipTestEnable = true;
>> diff --git a/src/mesa/main/attrib.c b/src/mesa/main/attrib.c
>> index cbe93ab6fa..a46fec73fd 100644
>> --- a/src/mesa/main/attrib.c
>> +++ b/src/mesa/main/attrib.c
>> @@ -72,7 +72,8 @@ struct gl_enable_attrib
>>     GLbitfield ClipPlanes;
>>     GLboolean ColorMaterial;
>>     GLboolean CullFace;
>> -   GLboolean DepthClamp;
>> +   GLboolean DepthClampNear;
>> +   GLboolean DepthClampFar;
>>     GLboolean DepthTest;
>>     GLboolean Dither;
>>     GLboolean Fog;
>> @@ -336,7 +337,8 @@ _mesa_PushAttrib(GLbitfield mask)
>>        attr->ClipPlanes = ctx->Transform.ClipPlanesEnabled;
>>        attr->ColorMaterial = ctx->Light.ColorMaterialEnabled;
>>        attr->CullFace = ctx->Polygon.CullFlag;
>> -      attr->DepthClamp = ctx->Transform.DepthClamp;
>> +      attr->DepthClampNear = ctx->Transform.DepthClampNear;
>> +      attr->DepthClampFar = ctx->Transform.DepthClampFar;
>>        attr->DepthTest = ctx->Depth.Test;
>>        attr->Dither = ctx->Color.DitherFlag;
>>        attr->Fog = ctx->Fog.Enabled;
>> @@ -627,8 +629,18 @@ pop_enable_group(struct gl_context *ctx, const struct gl_enable_attrib *enable)
>>     TEST_AND_UPDATE(ctx->Light.ColorMaterialEnabled, enable->ColorMaterial,
>>                     GL_COLOR_MATERIAL);
>>     TEST_AND_UPDATE(ctx->Polygon.CullFlag, enable->CullFace, GL_CULL_FACE);
>> -   TEST_AND_UPDATE(ctx->Transform.DepthClamp, enable->DepthClamp,
>> -                   GL_DEPTH_CLAMP);
>> +
>> +   if (!ctx->Extensions.AMD_depth_clamp_separate) {
>> +      TEST_AND_UPDATE(ctx->Transform.DepthClampNear && ctx->Transform.DepthClampFar,
>> +                      enable->DepthClampNear && enable->DepthClampFar,
>> +                      GL_DEPTH_CLAMP);
>> +   } else {
>> +      TEST_AND_UPDATE(ctx->Transform.DepthClampNear, enable->DepthClampNear,
>> +                      GL_DEPTH_CLAMP_NEAR_AMD);
>> +      TEST_AND_UPDATE(ctx->Transform.DepthClampFar, enable->DepthClampFar,
>> +                      GL_DEPTH_CLAMP_FAR_AMD);
>> +   }
>> +
>>     TEST_AND_UPDATE(ctx->Depth.Test, enable->DepthTest, GL_DEPTH_TEST);
>>     TEST_AND_UPDATE(ctx->Color.DitherFlag, enable->Dither, GL_DITHER);
>>     TEST_AND_UPDATE(ctx->Fog.Enabled, enable->Fog, GL_FOG);
>> @@ -1433,9 +1445,23 @@ _mesa_PopAttrib(void)
>>                 if (xform->RescaleNormals != ctx->Transform.RescaleNormals)
>>                    _mesa_set_enable(ctx, GL_RESCALE_NORMAL_EXT,
>>                                     ctx->Transform.RescaleNormals);
>> -               if (xform->DepthClamp != ctx->Transform.DepthClamp)
>> -                  _mesa_set_enable(ctx, GL_DEPTH_CLAMP,
>> -                                   ctx->Transform.DepthClamp);
>> +
>> +               if (!ctx->Extensions.AMD_depth_clamp_separate) {
>> +                  if (xform->DepthClampNear != ctx->Transform.DepthClampNear &&
>> +                      xform->DepthClampFar != ctx->Transform.DepthClampFar) {
>> +                     _mesa_set_enable(ctx, GL_DEPTH_CLAMP,
>> +                                      ctx->Transform.DepthClampNear &&
>> +                                      ctx->Transform.DepthClampFar);
>> +                  }
>> +               } else {
>> +                  if (xform->DepthClampNear != ctx->Transform.DepthClampNear)
>> +                     _mesa_set_enable(ctx, GL_DEPTH_CLAMP_NEAR_AMD,
>> +                                      ctx->Transform.DepthClampNear);
>> +                  if (xform->DepthClampFar != ctx->Transform.DepthClampFar)
>> +                     _mesa_set_enable(ctx, GL_DEPTH_CLAMP_FAR_AMD,
>> +                                      ctx->Transform.DepthClampFar);
>> +               }
>> +
>>                 if (ctx->Extensions.ARB_clip_control)
>>                    _mesa_ClipControl(xform->ClipOrigin, xform->ClipDepthMode);
>>              }
>> diff --git a/src/mesa/main/enable.c b/src/mesa/main/enable.c
>> index d1b2f3a962..30d275075d 100644
>> --- a/src/mesa/main/enable.c
>> +++ b/src/mesa/main/enable.c
>> @@ -1007,12 +1007,14 @@ _mesa_set_enable(struct gl_context *ctx, GLenum cap, GLboolean state)
>>           if (!_mesa_is_desktop_gl(ctx))
>>              goto invalid_enum_error;
>>           CHECK_EXTENSION(ARB_depth_clamp, cap);
>> -         if (ctx->Transform.DepthClamp == state)
>> +         if (ctx->Transform.DepthClampNear == state &&
>> +             ctx->Transform.DepthClampFar == state)
>>              return;
>>           FLUSH_VERTICES(ctx, ctx->DriverFlags.NewDepthClamp ? 0 :
>>                                                             _NEW_TRANSFORM);
>>           ctx->NewDriverState |= ctx->DriverFlags.NewDepthClamp;
>> -         ctx->Transform.DepthClamp = state;
>> +         ctx->Transform.DepthClampNear = state;
>> +         ctx->Transform.DepthClampFar = state;
>>           break;
>>
>>        case GL_FRAGMENT_SHADER_ATI:
>> @@ -1684,7 +1686,8 @@ _mesa_IsEnabled( GLenum cap )
>>           if (!_mesa_is_desktop_gl(ctx))
>>              goto invalid_enum_error;
>>           CHECK_EXTENSION(ARB_depth_clamp);
>> -         return ctx->Transform.DepthClamp;
>> +         return ctx->Transform.DepthClampNear ||
>> +                ctx->Transform.DepthClampFar;
>>
>>        case GL_FRAGMENT_SHADER_ATI:
>>           if (ctx->API != API_OPENGL_COMPAT)
>> diff --git a/src/mesa/main/get.c b/src/mesa/main/get.c
>> index f870b217db..16625e92e2 100644
>> --- a/src/mesa/main/get.c
>> +++ b/src/mesa/main/get.c
>> @@ -698,6 +698,10 @@ find_custom_value(struct gl_context *ctx, const struct value_desc *d, union valu
>>        v->value_int_4[3] = GET_COLORMASK_BIT(ctx->Color.ColorMask, 0, 3);
>>        break;
>>
>> +   case GL_DEPTH_CLAMP:
>> +      v->value_bool = ctx->Transform.DepthClampNear || ctx->Transform.DepthClampFar;
>> +      break;
>> +
>>     case GL_EDGE_FLAG:
>>        v->value_bool = ctx->Current.Attrib[VERT_ATTRIB_EDGEFLAG][0] == 1.0F;
>>        break;
>> diff --git a/src/mesa/main/get_hash_params.py b/src/mesa/main/get_hash_params.py
>> index 5c672a3312..ae1fc6f062 100644
>> --- a/src/mesa/main/get_hash_params.py
>> +++ b/src/mesa/main/get_hash_params.py
>> @@ -903,7 +903,7 @@ descriptor=[
>>    [ "DEPTH_BOUNDS_EXT", "CONTEXT_FLOAT2(Depth.BoundsMin), extra_EXT_depth_bounds_test" ],
>>
>>  # GL_ARB_depth_clamp
>> -  [ "DEPTH_CLAMP", "CONTEXT_BOOL(Transform.DepthClamp), extra_ARB_depth_clamp" ],
>> +  [ "DEPTH_CLAMP", "LOC_CUSTOM, TYPE_BOOLEAN, 0, extra_ARB_depth_clamp" ],
>>
>>  # GL_ATI_fragment_shader
>>    [ "FRAGMENT_SHADER_ATI", "CONTEXT_BOOL(ATIFragmentShader.Enabled), extra_ATI_fragment_shader" ],
>> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
>> index 3df657cc5d..eb4ccc1804 100644
>> --- a/src/mesa/main/mtypes.h
>> +++ b/src/mesa/main/mtypes.h
>> @@ -1282,7 +1282,6 @@ struct gl_transform_attrib
>>     GLboolean Normalize;                                /**< Normalize all normals? */
>>     GLboolean RescaleNormals;                   /**< GL_EXT_rescale_normal */
>>     GLboolean RasterPositionUnclipped;           /**< GL_IBM_rasterpos_clip */
>> -   GLboolean DepthClamp;                       /**< GL_ARB_depth_clamp */
>>     GLboolean DepthClampNear;                   /**< GL_AMD_depth_clamp_separate */
>>     GLboolean DepthClampFar;                    /**< GL_AMD_depth_clamp_separate */
>>     /** GL_ARB_clip_control */
>> diff --git a/src/mesa/main/rastpos.c b/src/mesa/main/rastpos.c
>> index 1ca83c78b0..7dd984caa1 100644
>> --- a/src/mesa/main/rastpos.c
>> +++ b/src/mesa/main/rastpos.c
>> @@ -61,16 +61,35 @@ viewclip_point_xy( const GLfloat v[] )
>>
>>
>>  /**
>> - * Clip a point against the far/near Z clipping planes.
>> + * Clip a point against the near Z clipping planes.
>>   *
>>   * \param v vertex vector describing the point to clip.
>>   *
>>   * \return zero if outside view volume, or one if inside.
>>   */
>>  static GLuint
>> -viewclip_point_z( const GLfloat v[] )
>> +viewclip_point_near_z( const GLfloat v[] )
>>  {
>> -   if (v[2] > v[3] || v[2] < -v[3] ) {
>> +   if (v[2] < -v[3]) {
>> +      return 0;
>> +   }
>> +   else {
>> +      return 1;
>> +   }
>> +}
>> +
>> +
>> +/**
>> + * Clip a point against the far Z clipping planes.
>> + *
>> + * \param v vertex vector describing the point to clip.
>> + *
>> + * \return zero if outside view volume, or one if inside.
>> + */
>> +static GLuint
>> +viewclip_point_far_z( const GLfloat v[] )
>> +{
>> +   if (v[2] > v[3]) {
>>        return 0;
>>     }
>>     else {
>> @@ -389,8 +408,14 @@ _mesa_RasterPos(struct gl_context *ctx, const GLfloat vObj[4])
>>        TRANSFORM_POINT( clip, ctx->ProjectionMatrixStack.Top->m, eye );
>>
>>        /* clip to view volume. */
>> -      if (!ctx->Transform.DepthClamp) {
>> -         if (viewclip_point_z(clip) == 0) {
>> +      if (!ctx->Transform.DepthClampNear) {
>> +         if (viewclip_point_near_z(clip) == 0) {
>> +            ctx->Current.RasterPosValid = GL_FALSE;
>> +            return;
>> +         }
>> +      }
>> +      if (!ctx->Transform.DepthClampFar) {
>> +         if (viewclip_point_far_z(clip) == 0) {
>>              ctx->Current.RasterPosValid = GL_FALSE;
>>              return;
>>           }
>> @@ -420,10 +445,22 @@ _mesa_RasterPos(struct gl_context *ctx, const GLfloat vObj[4])
>>        ctx->Current.RasterPos[2] = ndc[2] * scale[2] + translate[2];
>>        ctx->Current.RasterPos[3] = clip[3];
>>
>> -      if (ctx->Transform.DepthClamp) {
>> -        ctx->Current.RasterPos[3] = CLAMP(ctx->Current.RasterPos[3],
>> -                                          ctx->ViewportArray[0].Near,
>> -                                          ctx->ViewportArray[0].Far);
>> +      if (ctx->Transform.DepthClampNear &&
>> +          ctx->Transform.DepthClampFar) {
>> +         ctx->Current.RasterPos[3] = CLAMP(ctx->Current.RasterPos[3],
>> +                                           ctx->ViewportArray[0].Near,
>> +                                           ctx->ViewportArray[0].Far);
>> +      } else {
>> +         /* Clamp against near and far plane separately */
>> +         if (ctx->Transform.DepthClampNear) {
>> +            ctx->Current.RasterPos[3] = MIN2(ctx->ViewportArray[0].Near,
>> +                                             ctx->ViewportArray[0].Far);
>> +         }
>> +
>> +         if (ctx->Transform.DepthClampFar) {
>> +           ctx->Current.RasterPos[3] = MAX2(ctx->ViewportArray[0].Near,
>> +                                             ctx->ViewportArray[0].Far);
>> +         }
> 
> This doesn't clamp RasterPos correctly.
>

Ohh, I see. I am just setting RasterPos to MIN and MAX. I should have handled the ranges [min(n,f), 0] for near and [0, max(n,f)] for far plane. My bad. I will also include tests to catch this case. 
Thanks for pointing this out. 
 
> Marek
> 
>>        }
>>
>>        /* compute raster distance */
>> diff --git a/src/mesa/state_tracker/st_atom_rasterizer.c b/src/mesa/state_tracker/st_atom_rasterizer.c
>> index 0383b8ac4a..1f66b9d059 100644
>> --- a/src/mesa/state_tracker/st_atom_rasterizer.c
>> +++ b/src/mesa/state_tracker/st_atom_rasterizer.c
>> @@ -294,7 +294,8 @@ st_update_rasterizer(struct st_context *st)
>>     }
>>
>>     /* _NEW_TRANSFORM */
>> -   raster->depth_clip = !ctx->Transform.DepthClamp;
>> +   raster->depth_clip = !(ctx->Transform.DepthClampNear &&
>> +                          ctx->Transform.DepthClampFar);
>>     raster->clip_plane_enable = ctx->Transform.ClipPlanesEnabled;
>>     raster->clip_halfz = (ctx->Transform.ClipDepthMode == GL_ZERO_TO_ONE);
>>
>> diff --git a/src/mesa/state_tracker/st_cb_drawpixels.c b/src/mesa/state_tracker/st_cb_drawpixels.c
>> index b8895684bc..67bbb35850 100644
>> --- a/src/mesa/state_tracker/st_cb_drawpixels.c
>> +++ b/src/mesa/state_tracker/st_cb_drawpixels.c
>> @@ -677,7 +677,8 @@ draw_textured_quad(struct gl_context *ctx, GLint x, GLint y, GLfloat z,
>>                                          ctx->Color._ClampFragmentColor;
>>        rasterizer.half_pixel_center = 1;
>>        rasterizer.bottom_edge_rule = 1;
>> -      rasterizer.depth_clip = !ctx->Transform.DepthClamp;
>> +      rasterizer.depth_clip = !(ctx->Transform.DepthClampNear &&
>> +                                ctx->Transform.DepthClampFar);
>>        rasterizer.scissor = ctx->Scissor.EnableFlags;
>>        cso_set_rasterizer(cso, &rasterizer);
>>     }
>> diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
>> index 87b72e8197..f50b549a97 100644
>> --- a/src/mesa/swrast/s_span.c
>> +++ b/src/mesa/swrast/s_span.c
>> @@ -1219,7 +1219,7 @@ _swrast_write_rgba_span( struct gl_context *ctx, SWspan *span)
>>        if (!(span->arrayMask & SPAN_Z))
>>           _swrast_span_interpolate_z(ctx, span);
>>
>> -      if (ctx->Transform.DepthClamp)
>> +      if (ctx->Transform.DepthClampNear && ctx->Transform.DepthClampFar)
>>          _swrast_depth_clamp_span(ctx, span);
>>
>>        if (_mesa_stencil_is_enabled(ctx)) {
>> diff --git a/src/mesa/tnl/t_vb_program.c b/src/mesa/tnl/t_vb_program.c
>> index 19be5eed63..8d8aca614e 100644
>> --- a/src/mesa/tnl/t_vb_program.c
>> +++ b/src/mesa/tnl/t_vb_program.c
>> @@ -143,7 +143,8 @@ do_ndc_cliptest(struct gl_context *ctx, struct vp_stage_data *store)
>>                                              store->clipmask,
>>                                              &store->ormask,
>>                                              &store->andmask,
>> -                                           !ctx->Transform.DepthClamp );
>> +                                           !(ctx->Transform.DepthClampNear &&
>> +                                              ctx->Transform.DepthClampFar) );
>>     }
>>     else {
>>        VB->NdcPtr = NULL;
>> @@ -152,7 +153,8 @@ do_ndc_cliptest(struct gl_context *ctx, struct vp_stage_data *store)
>>                                              store->clipmask,
>>                                              &store->ormask,
>>                                              &store->andmask,
>> -                                           !ctx->Transform.DepthClamp );
>> +                                           !(ctx->Transform.DepthClampNear &&
>> +                                              ctx->Transform.DepthClampFar) );
>>     }
>>
>>     if (store->andmask) {
>> diff --git a/src/mesa/tnl/t_vb_vertex.c b/src/mesa/tnl/t_vb_vertex.c
>> index 71a32b4952..4fb3659a35 100644
>> --- a/src/mesa/tnl/t_vb_vertex.c
>> +++ b/src/mesa/tnl/t_vb_vertex.c
>> @@ -123,7 +123,7 @@ tnl_clip_prepare(struct gl_context *ctx)
>>     /* Neither the x86 nor sparc asm cliptest functions have been updated
>>      * for ARB_depth_clamp, so force the C paths.
>>      */
>> -   if (ctx->Transform.DepthClamp) {
>> +   if (ctx->Transform.DepthClampNear && ctx->Transform.DepthClampFar) {
>>        static GLboolean c_funcs_installed = GL_FALSE;
>>        if (!c_funcs_installed) {
>>           init_c_cliptest();
>> @@ -191,7 +191,8 @@ static GLboolean run_vertex_stage( struct gl_context *ctx,
>>                                             store->clipmask,
>>                                             &store->ormask,
>>                                             &store->andmask,
>> -                                           !ctx->Transform.DepthClamp );
>> +                                           !(ctx->Transform.DepthClampNear &&
>> +                                              ctx->Transform.DepthClampFar) );
>>     }
>>     else {
>>        VB->NdcPtr = NULL;
>> @@ -200,7 +201,8 @@ static GLboolean run_vertex_stage( struct gl_context *ctx,
>>                                             store->clipmask,
>>                                             &store->ormask,
>>                                             &store->andmask,
>> -                                           !ctx->Transform.DepthClamp );
>> +                                           !(ctx->Transform.DepthClampNear &&
>> +                                              ctx->Transform.DepthClampFar) );
>>     }
>>
>>     if (store->andmask)
>> --
>> 2.17.1
>>


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