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

3 files changed, 14 insertions, 2 deletions

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_ambient_occlusion.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_ambient_occlusion.glsl
index d6d6fbab971..eea8d19efce 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_ambient_occlusion.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_ambient_occlusion.glsl
@@ -3,7 +3,7 @@ void node_ambient_occlusion(
     vec4 color, float distance, vec3 normal, out vec4 result_color, out float result_ao)
 {
   vec3 bent_normal;
-  vec4 rand = texelFetch(utilTex, ivec3(ivec2(gl_FragCoord.xy) % LUT_SIZE, 2.0), 0);
+  vec4 rand = texelfetch_noise_tex(gl_FragCoord.xy);
   result_ao = occlusion_compute(normalize(normal), viewPosition, 1.0, rand, bent_normal);
   result_color = result_ao * color;
 }
diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_hair_info.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_hair_info.glsl
index 3b23ac976ae..6330daa4391 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_hair_info.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_hair_info.glsl
@@ -1,3 +1,15 @@
+
+float wang_hash_noise(uint s)
+{
+  s = (s ^ 61u) ^ (s >> 16u);
+  s *= 9u;
+  s = s ^ (s >> 4u);
+  s *= 0x27d4eb2du;
+  s = s ^ (s >> 15u);
+
+  return fract(float(s) / 4294967296.0);
+}
+
 void node_hair_info(out float is_strand,
                     out float intercept,
                     out float thickness,
diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_world_normals.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_world_normals.glsl
index f9691beee6f..d33465fa846 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_world_normals.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_world_normals.glsl
@@ -6,7 +6,7 @@ void world_normals_get(out vec3 N)
   vec3 B = normalize(cross(worldNormal, hairTangent));
   float cos_theta;
   if (hairThicknessRes == 1) {
-    vec4 rand = texelFetch(utilTex, ivec3(ivec2(gl_FragCoord.xy) % LUT_SIZE, 2.0), 0);
+    vec4 rand = texelfetch_noise_tex(gl_FragCoord.xy);
     /* Random cosine normal distribution on the hair surface. */
     cos_theta = rand.x * 2.0 - 1.0;
   }