EEVEE: GLSL refactor/cleanup

- add the use of DRWShaderLibrary to EEVEE's glsl codebase to reduce code
complexity and duplication.
- split bsdf_common_lib.glsl into multiple sub library which are now shared
with other engines.
- the surface shader code is now more organised and have its own files.
- change default world to use a material nodetree and make lookdev shader
more clear.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D8306

1 files changed, 21 insertions, 1 deletions

diff --git a/source/blender/draw/intern/shaders/common_hair_lib.glsl b/source/blender/draw/intern/shaders/common_hair_lib.glsl
index ffff631e34b..8684d82f228 100644
--- a/source/blender/draw/intern/shaders/common_hair_lib.glsl
+++ b/source/blender/draw/intern/shaders/common_hair_lib.glsl
@@ -95,7 +95,7 @@ void hair_get_interp_attrs(
  * For final drawing, the vertex index and the number of vertex per segment
  */
 
-#ifndef HAIR_PHASE_SUBDIV
+#if !defined(HAIR_PHASE_SUBDIV) && defined(GPU_VERTEX_SHADER)
 int hair_get_strand_id(void)
 {
   return gl_VertexID / (hairStrandsRes * hairThicknessRes);
@@ -206,4 +206,24 @@ vec3 hair_get_strand_pos(void)
   return texelFetch(hairPointBuffer, id).point_position;
 }
 
+vec2 hair_get_barycentric(void)
+{
+  /* To match cycles without breaking into individual segment we encode if we need to invert
+   * the first component into the second component. We invert if the barycentricTexCo.y
+   * is NOT 0.0 or 1.0. */
+  int id = hair_get_base_id();
+  return vec2(float((id % 2) == 1), float(((id % 4) % 3) > 0));
+}
+
 #endif
+
+/* To be fed the result of hair_get_barycentric from vertex shader. */
+vec2 hair_resolve_barycentric(vec2 vert_barycentric)
+{
+  if (fract(vert_barycentric.y) != 0.0) {
+    return vec2(vert_barycentric.x, 0.0);
+  }
+  else {
+    return vec2(1.0 - vert_barycentric.x, 0.0);
+  }
+}