GPU: Make nodetree GLSL Codegen render engine agnostic

This commit removes all EEVEE specific code from the `gpu_shader_material*.glsl`
files. It defines a clear interface to evaluate the closure nodes leaving
more flexibility to the render engine.

Some of the long standing workaround are fixed:
- bump mapping support is no longer duplicating a lot of node and is instead
  compiled into a function call.
- bump rewiring to Normal socket is no longer needed as we now use a global
  `g_data.N` for that.


Closure sampling with upstread weight eval is now supported if the engine needs
it.

This also makes all the material GLSL sources use `GPUSource` for better
debugging experience. The `GPUFunction` parsing now happens in `GPUSource`
creation.

The whole `GPUCodegen` now uses the `ShaderCreateInfo` and is object type
agnostic. Is has also been rewritten in C++.

This patch changes a view behavior for EEVEE:
- Mix shader node factor imput is now clamped.
- Tangent Vector displacement behavior is now matching cycles.
- The chosen BSDF used for SSR might change.
- Hair shading may have very small changes on very large hairs when using hair
  polygon stripes.
- ShaderToRGB node will remove any SSR and SSS form a shader.
- SSS radius input now is no longer a scaling factor but defines an average
  radius. The SSS kernel "shape" (radii) are still defined by the socket default
  values.

Appart from the listed changes no other regressions are expected.

1 files changed, 3 insertions, 21 deletions

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_volume_info.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_volume_info.glsl
index e6d7b9d3721..464cf5227b4 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_volume_info.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_volume_info.glsl
@@ -4,14 +4,8 @@ uniform vec3 volumeColor = vec3(1.0);
 uniform vec2 volumeTemperature = vec2(0.0);
 
 /* Generic volume attribute. */
-void node_attribute_volume(sampler3D tex, mat4 transform, out vec3 outvec)
+void node_attribute_volume(sampler3D tex, mat4 transform, vec3 cos, out vec3 outvec)
 {
-#if defined(MESH_SHADER) && defined(VOLUMETRICS)
-  vec3 cos = volumeObjectLocalCoord;
-#else
-  vec3 cos = vec3(0.0);
-#endif
-
   /* Optional per-grid transform. */
   if (transform[3][3] != 0.0) {
     cos = (transform * vec4(cos, 1.0)).xyz;
@@ -21,14 +15,8 @@ void node_attribute_volume(sampler3D tex, mat4 transform, out vec3 outvec)
 }
 
 /* Special color attribute for smoke. */
-void node_attribute_volume_color(sampler3D tex, mat4 transform, out vec3 outvec)
+void node_attribute_volume_color(sampler3D tex, mat4 transform, vec3 cos, out vec3 outvec)
 {
-#if defined(MESH_SHADER) && defined(VOLUMETRICS)
-  vec3 cos = volumeObjectLocalCoord;
-#else
-  vec3 cos = vec3(0.0);
-#endif
-
   /* Optional per-grid transform. */
   if (transform[3][3] != 0.0) {
     cos = (transform * vec4(cos, 1.0)).xyz;
@@ -44,14 +32,8 @@ void node_attribute_volume_color(sampler3D tex, mat4 transform, out vec3 outvec)
 }
 
 /* Special temperature attribute for smoke. */
-void node_attribute_volume_temperature(sampler3D tex, mat4 transform, out float outf)
+void node_attribute_volume_temperature(sampler3D tex, mat4 transform, vec3 cos, out float outf)
 {
-#if defined(MESH_SHADER) && defined(VOLUMETRICS)
-  vec3 cos = volumeObjectLocalCoord;
-#else
-  vec3 cos = vec3(0.0);
-#endif
-
   /* Optional per-grid transform. */
   if (transform[3][3] != 0.0) {
     cos = (transform * vec4(cos, 1.0)).xyz;