EEVEE: Refactor of eevee_material.c

These are the modifications:

-With DRW modification we reduce the number of passes we need to populate.
-Rename passes for consistent naming.
-Reduce complexity in code compilation
-Cleanup how renderpass accumulation passes are setup, using pass instances.
-Make sculpt mode compatible with shadows
-Make hair passes compatible with SSS
-Error shader and lookdev materials now use standalone materials.
-Support default shader (world and material) using a default nodetree internally.
-Change BLEND_CLIP to be emulated by gpu nodetree. Making less shader variations.
-Use BLI_memblock for cache memory allocation.
-Renderpasses are handled by switching a UBO ref bind.

One major hack in this patch is the use of modified pointer as ghash keys.
This rely on the assumption that the keys will never overlap because the
number of options per key will never be bigger than the pointed struct.

The use of one single nodetree to support default material is also a bit hacky
since it won't support concurent usage of this nodetree.
(see EEVEE_shader_default_surface_nodetree)

Another change is that objects with shader errors now appear solid magenta instead
of shaded magenta. This is only because of code reuse purpose but could be changed
if really needed.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D7642

1 files changed, 6 insertions, 15 deletions

diff --git a/source/blender/draw/engines/eevee/shaders/prepass_frag.glsl b/source/blender/draw/engines/eevee/shaders/prepass_frag.glsl
index b49dbfceba2..9acd8f998f6 100644
--- a/source/blender/draw/engines/eevee/shaders/prepass_frag.glsl
+++ b/source/blender/draw/engines/eevee/shaders/prepass_frag.glsl
@@ -45,26 +45,22 @@ float hashed_alpha_threshold(vec3 co)
   /* Find our final, uniformly distributed alpha threshold. */
   float threshold = (x < one_a) ? ((x < a) ? cases.x : cases.y) : cases.z;
 
+  /* Jitter the threshold for TAA accumulation. */
+  threshold = fract(threshold + alphaHashOffset);
+
   /* Avoids threshold == 0. */
   threshold = clamp(threshold, 1.0e-6, 1.0);
 
-  /* Jitter the threshold for TAA accumulation. */
-  return fract(threshold + alphaHashOffset);
+  return threshold;
 }
 
 #endif
 
-#ifdef USE_ALPHA_CLIP
-uniform float alphaThreshold;
-#endif
+#define NODETREE_EXEC
 
 void main()
 {
-  /* For now do nothing.
-   * In the future, output object motion blur. */
-
-#if defined(USE_ALPHA_HASH) || defined(USE_ALPHA_CLIP)
-#  define NODETREE_EXEC
+#if defined(USE_ALPHA_HASH)
 
   Closure cl = nodetree_exec();
 
@@ -75,11 +71,6 @@ void main()
   if (opacity < hashed_alpha_threshold(worldPosition)) {
     discard;
   }
-#  elif defined(USE_ALPHA_CLIP)
-  /* Alpha clip */
-  if (opacity <= alphaThreshold) {
-    discard;
-  }
 #  endif
 #endif
 }