EEVEE: Speedup: Don't request orco layer if not needed

Should speed up eevee mesh update a tiny bit in certain particular cases
(deform modifier + (shader using texcoord (but not generated output) OR
principled bsdf OR geometry node (except tangent output))).

3 files changed, 12 insertions, 5 deletions

diff --git a/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c b/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
index 595ddf27d0a..3340054396d 100644
--- a/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
+++ b/source/blender/nodes/shader/nodes/node_shader_bsdf_principled.c
@@ -120,6 +120,7 @@ static int node_shader_gpu_bsdf_principled(GPUMaterial *mat,
     GPU_link(mat, "world_normals_get", &in[20].link);
   }
 
+#if 0 /* Not used at the moment. */
   /* Tangents */
   if (!in[21].link) {
     GPUNodeLink *orco = GPU_attribute(CD_ORCO, "");
@@ -131,6 +132,7 @@ static int node_shader_gpu_bsdf_principled(GPUMaterial *mat,
              GPU_builtin(GPU_OBJECT_MATRIX),
              &in[21].link);
   }
+#endif
 
   bool use_diffuse = socket_not_one(4) && socket_not_one(15);
   bool use_subsurf = socket_not_zero(1) && use_diffuse && node->sss_id > 0;
diff --git a/source/blender/nodes/shader/nodes/node_shader_geometry.c b/source/blender/nodes/shader/nodes/node_shader_geometry.c
index df9a8ac8318..d94141c3699 100644
--- a/source/blender/nodes/shader/nodes/node_shader_geometry.c
+++ b/source/blender/nodes/shader/nodes/node_shader_geometry.c
@@ -41,9 +41,11 @@ static int node_shader_gpu_geometry(GPUMaterial *mat,
 {
   /* HACK: Don't request GPU_BARYCENTRIC_TEXCO if not used because it will
    * trigger the use of geometry shader (and the performance penalty it implies). */
-  float val[2] = {0.0f, 0.0f};
+  float val[4] = {0.0f, 0.0f, 0.0f, 0.0f};
   GPUNodeLink *bary_link = (!out[5].hasoutput) ? GPU_constant(val) :
                                                  GPU_builtin(GPU_BARYCENTRIC_TEXCO);
+  /* Opti: don't request orco if not needed. */
+  GPUNodeLink *orco_link = (!out[2].hasoutput) ? GPU_constant(val) : GPU_attribute(CD_ORCO, "");
 
   return GPU_stack_link(mat,
                         node,
@@ -52,7 +54,7 @@ static int node_shader_gpu_geometry(GPUMaterial *mat,
                         out,
                         GPU_builtin(GPU_VIEW_POSITION),
                         GPU_builtin(GPU_WORLD_NORMAL),
-                        GPU_attribute(CD_ORCO, ""),
+                        orco_link,
                         GPU_builtin(GPU_OBJECT_MATRIX),
                         GPU_builtin(GPU_INVERSE_VIEW_MATRIX),
                         bary_link);
diff --git a/source/blender/nodes/shader/nodes/node_shader_tex_coord.c b/source/blender/nodes/shader/nodes/node_shader_tex_coord.c
index 637aeb3c182..068458b7e1f 100644
--- a/source/blender/nodes/shader/nodes/node_shader_tex_coord.c
+++ b/source/blender/nodes/shader/nodes/node_shader_tex_coord.c
@@ -45,14 +45,17 @@ static int node_shader_gpu_tex_coord(GPUMaterial *mat,
   GPUNodeLink *inv_obmat = (ob != NULL) ? GPU_uniform(&ob->imat[0][0]) :
                                           GPU_builtin(GPU_INVERSE_OBJECT_MATRIX);
 
-  /* TODO only request orco if needed. */
-  GPUNodeLink *orco = GPU_attribute(CD_ORCO, "");
+  /* Opti: don't request orco if not needed. */
+  GPUNodeLink *orco = (!out[0].hasoutput) ? GPU_constant((float[4]){0.0f, 0.0f, 0.0f, 0.0f}) :
+                                            GPU_attribute(CD_ORCO, "");
   GPUNodeLink *mtface = GPU_attribute(CD_MTFACE, "");
   GPUNodeLink *viewpos = GPU_builtin(GPU_VIEW_POSITION);
   GPUNodeLink *worldnor = GPU_builtin(GPU_WORLD_NORMAL);
   GPUNodeLink *texcofacs = GPU_builtin(GPU_CAMERA_TEXCO_FACTORS);
 
-  GPU_link(mat, "generated_from_orco", orco, &orco);
+  if (out[0].hasoutput) {
+    GPU_link(mat, "generated_from_orco", orco, &orco);
+  }
 
   GPU_stack_link(
       mat, node, "node_tex_coord", in, out, viewpos, worldnor, inv_obmat, texcofacs, orco, mtface);