i965: Move legacy clip plane handling to vec4_vs_visitor.

This is now only used for the vertex shader, so it makes sense to get it
out of any paths run by the geometry shader.

Instead of passing the gl_clip_plane array into the run() method (which
is shared among all subclasses), we add it as a vec4_vs_visitor
constructor parameter.  This eliminates the bogus NULL parameter in the
GS case.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chris Forbes <chrisf@ijw.co.nz>

6 files changed, 74 insertions, 67 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index 0c2326c..073e90b 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -1721,7 +1721,7 @@ vec4_visitor::emit_shader_time_write(int shader_time_subindex, src_reg value)
 }
 
 bool
-vec4_visitor::run(gl_clip_plane *clip_planes)
+vec4_visitor::run()
 {
    bool use_vec4_nir =
       compiler->glsl_compiler_options[stage].NirOptions != NULL;
@@ -1750,9 +1750,6 @@ vec4_visitor::run(gl_clip_plane *clip_planes)
    }
    base_ir = NULL;
 
-   if (key->nr_userclip_plane_consts > 0)
-      setup_uniform_clipplane_values(clip_planes);
-
    emit_thread_end();
 
    calculate_cfg();
@@ -1979,9 +1976,10 @@ brw_vs_emit(struct brw_context *brw,
       prog_data->base.dispatch_mode = DISPATCH_MODE_4X2_DUAL_OBJECT;
 
       vec4_vs_visitor v(brw->intelScreen->compiler, brw, key, prog_data,
-                        vp, prog, mem_ctx, st_index,
+                        vp, prog, brw_select_clip_planes(&brw->ctx),
+                        mem_ctx, st_index,
                         !_mesa_is_gles3(&brw->ctx));
-      if (!v.run(brw_select_clip_planes(&brw->ctx))) {
+      if (!v.run()) {
          if (prog) {
             prog->LinkStatus = false;
             ralloc_strcat(&prog->InfoLog, v.fail_msg);
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h
index 673a29e..7c31932 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_vec4.h
@@ -173,10 +173,9 @@ public:
 
    struct hash_table *variable_ht;
 
-   bool run(gl_clip_plane *clip_planes);
+   bool run();
    void fail(const char *msg, ...);
 
-   void setup_uniform_clipplane_values(gl_clip_plane *clip_planes);
    virtual void setup_vec4_uniform_value(unsigned param_offset,
                                          const gl_constant_value *values,
                                          unsigned n);
@@ -359,7 +358,6 @@ public:
 
    void emit_ndc_computation();
    void emit_psiz_and_flags(dst_reg reg);
-   void emit_clip_distances(dst_reg reg, int offset);
    vec4_instruction *emit_generic_urb_slot(dst_reg reg, int varying);
    void emit_urb_slot(dst_reg reg, int varying);
 
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
index 019efec..4fd626f 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
@@ -679,7 +679,7 @@ brw_gs_emit(struct brw_context *brw,
 
          vec4_gs_visitor v(brw->intelScreen->compiler, brw,
                            c, prog, mem_ctx, true /* no_spills */, st_index);
-         if (v.run(NULL /* clip planes */)) {
+         if (v.run()) {
             return generate_assembly(brw, prog, &c->gp->program.Base,
                                      &c->prog_data.base, mem_ctx, v.cfg,
                                      final_assembly_size);
@@ -727,7 +727,7 @@ brw_gs_emit(struct brw_context *brw,
                                c, prog, mem_ctx, false /* no_spills */,
                                st_index);
 
-   if (!gs->run(NULL /* clip planes */)) {
+   if (!gs->run()) {
       prog->LinkStatus = false;
       ralloc_strcat(&prog->InfoLog, gs->fail_msg);
    } else {
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
index 4d3d281..978d28c 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
@@ -755,22 +755,6 @@ vec4_visitor::setup_uniform_values(ir_variable *ir)
    }
 }
 
-void
-vec4_visitor::setup_uniform_clipplane_values(gl_clip_plane *clip_planes)
-{
-   for (int i = 0; i < key->nr_userclip_plane_consts; ++i) {
-      assert(this->uniforms < uniform_array_size);
-      this->uniform_vector_size[this->uniforms] = 4;
-      this->userplane[i] = dst_reg(UNIFORM, this->uniforms);
-      this->userplane[i].type = BRW_REGISTER_TYPE_F;
-      for (int j = 0; j < 4; ++j) {
-         stage_prog_data->param[this->uniforms * 4 + j] =
-            (gl_constant_value *) &clip_planes[i][j];
-      }
-      ++this->uniforms;
-   }
-}
-
 /* Our support for builtin uniforms is even scarier than non-builtin.
  * It sits on top of the PROG_STATE_VAR parameters that are
  * automatically updated from GL context state.
@@ -3203,35 +3187,6 @@ vec4_visitor::emit_psiz_and_flags(dst_reg reg)
    }
 }
 
-void
-vec4_visitor::emit_clip_distances(dst_reg reg, int offset)
-{
-   /* From the GLSL 1.30 spec, section 7.1 (Vertex Shader Special Variables):
-    *
-    *     "If a linked set of shaders forming the vertex stage contains no
-    *     static write to gl_ClipVertex or gl_ClipDistance, but the
-    *     application has requested clipping against user clip planes through
-    *     the API, then the coordinate written to gl_Position is used for
-    *     comparison against the user clip planes."
-    *
-    * This function is only called if the shader didn't write to
-    * gl_ClipDistance.  Accordingly, we use gl_ClipVertex to perform clipping
-    * if the user wrote to it; otherwise we use gl_Position.
-    */
-   gl_varying_slot clip_vertex = VARYING_SLOT_CLIP_VERTEX;
-   if (!(prog_data->vue_map.slots_valid & VARYING_BIT_CLIP_VERTEX)) {
-      clip_vertex = VARYING_SLOT_POS;
-   }
-
-   for (int i = 0; i + offset < key->nr_userclip_plane_consts && i < 4;
-        ++i) {
-      reg.writemask = 1 << i;
-      emit(DP4(reg,
-               src_reg(output_reg[clip_vertex]),
-               src_reg(this->userplane[i + offset])));
-   }
-}
-
 vec4_instruction *
 vec4_visitor::emit_generic_urb_slot(dst_reg reg, int varying)
 {
@@ -3354,17 +3309,6 @@ vec4_visitor::emit_vertex()
       emit_ndc_computation();
    }
 
-   /* Lower legacy ff and ClipVertex clipping to clip distances */
-   if (key->nr_userclip_plane_consts > 0) {
-      current_annotation = "user clip distances";
-
-      output_reg[VARYING_SLOT_CLIP_DIST0] = dst_reg(this, glsl_type::vec4_type);
-      output_reg[VARYING_SLOT_CLIP_DIST1] = dst_reg(this, glsl_type::vec4_type);
-
-      emit_clip_distances(output_reg[VARYING_SLOT_CLIP_DIST0], 0);
-      emit_clip_distances(output_reg[VARYING_SLOT_CLIP_DIST1], 4);
-   }
-
    /* We may need to split this up into several URB writes, so do them in a
     * loop.
     */
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp
index 620f652..f81ee4e 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp
@@ -202,8 +202,68 @@ vec4_vs_visitor::emit_urb_write_opcode(bool complete)
 
 
 void
+vec4_vs_visitor::emit_clip_distances(dst_reg reg, int offset)
+{
+   /* From the GLSL 1.30 spec, section 7.1 (Vertex Shader Special Variables):
+    *
+    *     "If a linked set of shaders forming the vertex stage contains no
+    *     static write to gl_ClipVertex or gl_ClipDistance, but the
+    *     application has requested clipping against user clip planes through
+    *     the API, then the coordinate written to gl_Position is used for
+    *     comparison against the user clip planes."
+    *
+    * This function is only called if the shader didn't write to
+    * gl_ClipDistance.  Accordingly, we use gl_ClipVertex to perform clipping
+    * if the user wrote to it; otherwise we use gl_Position.
+    */
+   gl_varying_slot clip_vertex = VARYING_SLOT_CLIP_VERTEX;
+   if (!(prog_data->vue_map.slots_valid & VARYING_BIT_CLIP_VERTEX)) {
+      clip_vertex = VARYING_SLOT_POS;
+   }
+
+   for (int i = 0; i + offset < key->base.nr_userclip_plane_consts && i < 4;
+        ++i) {
+      reg.writemask = 1 << i;
+      emit(DP4(reg,
+               src_reg(output_reg[clip_vertex]),
+               src_reg(this->userplane[i + offset])));
+   }
+}
+
+
+void
+vec4_vs_visitor::setup_uniform_clipplane_values()
+{
+   for (int i = 0; i < key->base.nr_userclip_plane_consts; ++i) {
+      assert(this->uniforms < uniform_array_size);
+      this->uniform_vector_size[this->uniforms] = 4;
+      this->userplane[i] = dst_reg(UNIFORM, this->uniforms);
+      this->userplane[i].type = BRW_REGISTER_TYPE_F;
+      for (int j = 0; j < 4; ++j) {
+         stage_prog_data->param[this->uniforms * 4 + j] =
+            (gl_constant_value *) &clip_planes[i][j];
+      }
+      ++this->uniforms;
+   }
+}
+
+
+void
 vec4_vs_visitor::emit_thread_end()
 {
+   setup_uniform_clipplane_values();
+
+   /* Lower legacy ff and ClipVertex clipping to clip distances */
+   if (key->base.nr_userclip_plane_consts > 0) {
+      current_annotation = "user clip distances";
+
+      output_reg[VARYING_SLOT_CLIP_DIST0] = dst_reg(this, glsl_type::vec4_type);
+      output_reg[VARYING_SLOT_CLIP_DIST1] = dst_reg(this, glsl_type::vec4_type);
+
+      emit_clip_distances(output_reg[VARYING_SLOT_CLIP_DIST0], 0);
+      emit_clip_distances(output_reg[VARYING_SLOT_CLIP_DIST1], 4);
+   }
+
    /* For VS, we always end the thread by emitting a single vertex.
     * emit_urb_write_opcode() will take care of setting the eot flag on the
     * SEND instruction.
@@ -218,6 +278,7 @@ vec4_vs_visitor::vec4_vs_visitor(const struct brw_compiler *compiler,
                                  struct brw_vs_prog_data *vs_prog_data,
                                  struct gl_vertex_program *vp,
                                  struct gl_shader_program *prog,
+                                 gl_clip_plane *clip_planes,
                                  void *mem_ctx,
                                  int shader_time_index,
                                  bool use_legacy_snorm_formula)
@@ -229,6 +290,7 @@ vec4_vs_visitor::vec4_vs_visitor(const struct brw_compiler *compiler,
      key(key),
      vs_prog_data(vs_prog_data),
      vp(vp),
+     clip_planes(clip_planes),
      use_legacy_snorm_formula(use_legacy_snorm_formula)
 {
 }
diff --git a/src/mesa/drivers/dri/i965/brw_vs.h b/src/mesa/drivers/dri/i965/brw_vs.h
index 1d9bee1..e98679a 100644
--- a/src/mesa/drivers/dri/i965/brw_vs.h
+++ b/src/mesa/drivers/dri/i965/brw_vs.h
@@ -90,6 +90,7 @@ public:
                    struct brw_vs_prog_data *vs_prog_data,
                    struct gl_vertex_program *vp,
                    struct gl_shader_program *prog,
+                   gl_clip_plane *clip_planes,
                    void *mem_ctx,
                    int shader_time_index,
                    bool use_legacy_snorm_formula);
@@ -107,6 +108,8 @@ protected:
 private:
    int setup_attributes(int payload_reg);
    void setup_vp_regs();
+   void setup_uniform_clipplane_values();
+   void emit_clip_distances(dst_reg reg, int offset);
    dst_reg get_vp_dst_reg(const prog_dst_register &dst);
    src_reg get_vp_src_reg(const prog_src_register &src);
 
@@ -116,6 +119,8 @@ private:
    src_reg *vp_temp_regs;
    src_reg vp_addr_reg;
 
+   gl_clip_plane *clip_planes;
+
    bool use_legacy_snorm_formula;
 };