mesa/st: Tie depth_clamp code into other shaders (GS and TES)

v2: Use file scope defined depth_range_state  in common
v3: - don't use the one_shader_variant property, as this is
      not correct (Marek)
    - also use tests on available shader stages to enable
      depth_clamp lowering
v4: Don't use key.st, use st directly (Marek)

Signed-off-by: Gert Wollny <[email protected]>
Reviewed-by: Reviewed-by: Marek Olšák <[email protected]>

3 files changed, 36 insertions, 1 deletions

diff --git a/src/mesa/state_tracker/st_atom_shader.c b/src/mesa/state_tracker/st_atom_shader.c
index a10cc21021c..f9c61c055cc 100644
--- a/src/mesa/state_tracker/st_atom_shader.c
+++ b/src/mesa/state_tracker/st_atom_shader.c
@@ -251,6 +251,17 @@ st_update_common_program(struct st_context *st, struct gl_program *prog,
                           VARYING_SLOT_COL1 |
                           VARYING_SLOT_BFC0 |
                           VARYING_SLOT_BFC1));
+
+      key.lower_depth_clamp =
+            (pipe_shader == PIPE_SHADER_GEOMETRY || !st->gp) &&
+            st->clamp_frag_depth_in_shader &&
+            (st->ctx->Transform.DepthClampNear ||
+             st->ctx->Transform.DepthClampFar);
+
+      if (key.lower_depth_clamp)
+         key.clip_negative_one_to_one =
+               st->ctx->Transform.ClipDepthMode == GL_NEGATIVE_ONE_TO_ONE;
+
    }
 
    return st_get_basic_variant(st, pipe_shader, stp, &key)->driver_shader;
diff --git a/src/mesa/state_tracker/st_program.c b/src/mesa/state_tracker/st_program.c
index fa7552b2592..df6c8e81f55 100644
--- a/src/mesa/state_tracker/st_program.c
+++ b/src/mesa/state_tracker/st_program.c
@@ -1697,8 +1697,27 @@ st_get_basic_variant(struct st_context *st,
                NIR_PASS_V(tgsi.ir.nir, nir_lower_clamp_color_outputs);
 
             tgsi.stream_output = prog->tgsi.stream_output;
-	 } else
+	 } else {
+            if (key->lower_depth_clamp) {
+               struct gl_program_parameter_list *params = prog->Base.Parameters;
+
+               unsigned depth_range_const =
+                     _mesa_add_state_reference(params, depth_range_state);
+
+               const struct tgsi_token *tokens;
+               tokens =
+                     st_tgsi_lower_depth_clamp(prog->tgsi.tokens,
+                                               depth_range_const,
+                                               key->clip_negative_one_to_one);
+
+               if (tokens != prog->tgsi.tokens)
+                  tgsi_free_tokens(prog->tgsi.tokens);
+
+               prog->tgsi.tokens = tokens;
+               prog->num_tgsi_tokens = tgsi_num_tokens(tokens);
+            }
 	    tgsi = prog->tgsi;
+         }
          /* fill in new variant */
          switch (pipe_shader) {
          case PIPE_SHADER_TESS_CTRL:
diff --git a/src/mesa/state_tracker/st_program.h b/src/mesa/state_tracker/st_program.h
index eefa340e5cb..77b335993a5 100644
--- a/src/mesa/state_tracker/st_program.h
+++ b/src/mesa/state_tracker/st_program.h
@@ -269,6 +269,11 @@ struct st_basic_variant_key
 
    /** For compat profile */
    bool clamp_color;
+
+   /** both for ARB_depth_clamp */
+   bool lower_depth_clamp;
+   bool clip_negative_one_to_one;
+
 };