1 files changed, 33 insertions, 0 deletions
diff --git a/source/blender/draw/engines/eevee/shaders/eevee_surface_mesh_geom.glsl b/source/blender/draw/engines/eevee/shaders/eevee_surface_mesh_geom.glsl
new file mode 100644
index 00000000000..29558a0958e
--- /dev/null
+++ b/source/blender/draw/engines/eevee/shaders/eevee_surface_mesh_geom.glsl
@@ -0,0 +1,33 @@
+
+/**
+ * Optional geometry shader stage to compute barycentric coords
+ * Only needed / compatible with mesh or gpencil geometry.
+ * Main is generated in eevee_shader.cc to avoid compilation issue on some drivers.
+ */
+
+layout(triangles) in;
+layout(triangle_strip, max_vertices = 3) out;
+
+vec3 calc_barycentric_distances(vec3 pos0, vec3 pos1, vec3 pos2)
+{
+  vec3 edge21 = pos2 - pos1;
+  vec3 edge10 = pos1 - pos0;
+  vec3 edge02 = pos0 - pos2;
+  vec3 d21 = normalize(edge21);
+  vec3 d10 = normalize(edge10);
+  vec3 d02 = normalize(edge02);
+
+  vec3 dists;
+  float d = dot(d21, edge02);
+  dists.x = sqrt(dot(edge02, edge02) - d * d);
+  d = dot(d02, edge10);
+  dists.y = sqrt(dot(edge10, edge10) - d * d);
+  d = dot(d10, edge21);
+  dists.z = sqrt(dot(edge21, edge21) - d * d);
+  return dists;
+}
+
+vec2 calc_barycentric_co(int vertid)
+{
+  return vec2((vertid % 3) == 0, (vertid % 3) == 1);
+}