2 files changed, 33 insertions, 3 deletions
diff --git a/source/blender/draw/intern/shaders/common_subdiv_lib.glsl b/source/blender/draw/intern/shaders/common_subdiv_lib.glsl
index a620905622a..44048e73ee5 100644
--- a/source/blender/draw/intern/shaders/common_subdiv_lib.glsl
+++ b/source/blender/draw/intern/shaders/common_subdiv_lib.glsl
@@ -107,6 +107,10 @@ struct PosNorLoop {
   float flag;
 };
 
+struct LoopNormal {
+  float nx, ny, nz, flag;
+};
+
 vec3 get_vertex_pos(PosNorLoop vertex_data)
 {
   return vec3(vertex_data.x, vertex_data.y, vertex_data.z);
@@ -117,6 +121,16 @@ vec3 get_vertex_nor(PosNorLoop vertex_data)
   return vec3(vertex_data.nx, vertex_data.ny, vertex_data.nz);
 }
 
+LoopNormal get_normal_and_flag(PosNorLoop vertex_data)
+{
+  LoopNormal loop_nor;
+  loop_nor.nx = vertex_data.nx;
+  loop_nor.ny = vertex_data.ny;
+  loop_nor.nz = vertex_data.nz;
+  loop_nor.flag = vertex_data.flag;
+  return loop_nor;
+}
+
 void set_vertex_pos(inout PosNorLoop vertex_data, vec3 pos)
 {
   vertex_data.x = pos.x;
diff --git a/source/blender/draw/intern/shaders/common_subdiv_vbo_lnor_comp.glsl b/source/blender/draw/intern/shaders/common_subdiv_vbo_lnor_comp.glsl
index 8b4a5dd14f3..c3aa74ec18c 100644
--- a/source/blender/draw/intern/shaders/common_subdiv_vbo_lnor_comp.glsl
+++ b/source/blender/draw/intern/shaders/common_subdiv_vbo_lnor_comp.glsl
@@ -13,9 +13,14 @@ layout(std430, binding = 2) readonly buffer extraCoarseFaceData
 
 layout(std430, binding = 3) writeonly buffer outputLoopNormals
 {
-  vec3 output_lnor[];
+  LoopNormal output_lnor[];
 };
 
+bool is_face_selected(uint coarse_quad_index)
+{
+  return (extra_coarse_face_data[coarse_quad_index] & coarse_face_select_mask) != 0;
+}
+
 void main()
 {
   /* We execute for each quad. */
@@ -34,7 +39,7 @@ void main()
     /* Face is smooth, use vertex normals. */
     for (int i = 0; i < 4; i++) {
       PosNorLoop pos_nor_loop = pos_nor[start_loop_index + i];
-      output_lnor[start_loop_index + i] = get_vertex_nor(pos_nor_loop);
+      output_lnor[start_loop_index + i] = get_normal_and_flag(pos_nor_loop);
     }
   }
   else {
@@ -50,8 +55,19 @@ void main()
     add_newell_cross_v3_v3v3(face_normal, v3, v0);
 
     face_normal = normalize(face_normal);
+
+    LoopNormal loop_normal;
+    loop_normal.nx = face_normal.x;
+    loop_normal.ny = face_normal.y;
+    loop_normal.nz = face_normal.z;
+    loop_normal.flag = 0.0;
+
+    if (is_face_selected(coarse_quad_index)) {
+      loop_normal.flag = 1.0;
+    }
+
     for (int i = 0; i < 4; i++) {
-      output_lnor[start_loop_index + i] = face_normal;
+      output_lnor[start_loop_index + i] = loop_normal;
     }
   }
 }