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, 12 insertions, 9 deletions

diff --git a/source/blender/draw/intern/draw_shader_shared.h b/source/blender/draw/intern/draw_shader_shared.h
index 5fc76bc25e6..58875c0496a 100644
--- a/source/blender/draw/intern/draw_shader_shared.h
+++ b/source/blender/draw/intern/draw_shader_shared.h
@@ -36,16 +36,19 @@ struct ViewInfos {
 };
 BLI_STATIC_ASSERT_ALIGN(ViewInfos, 16)
 
+/* Do not override old definitions if the shader uses this header but not shader info. */
+#ifdef USE_GPU_SHADER_CREATE_INFO
 /* TODO(@fclem): Mass rename. */
-#define ViewProjectionMatrix drw_view.persmat
-#define ViewProjectionMatrixInverse drw_view.persinv
-#define ViewMatrix drw_view.viewmat
-#define ViewMatrixInverse drw_view.viewinv
-#define ProjectionMatrix drw_view.winmat
-#define ProjectionMatrixInverse drw_view.wininv
-#define clipPlanes drw_view.clip_planes
-#define ViewVecs drw_view.viewvecs
-#define CameraTexCoFactors drw_view.viewcamtexcofac
+#  define ViewProjectionMatrix drw_view.persmat
+#  define ViewProjectionMatrixInverse drw_view.persinv
+#  define ViewMatrix drw_view.viewmat
+#  define ViewMatrixInverse drw_view.viewinv
+#  define ProjectionMatrix drw_view.winmat
+#  define ProjectionMatrixInverse drw_view.wininv
+#  define clipPlanes drw_view.clip_planes
+#  define ViewVecs drw_view.viewvecs
+#  define CameraTexCoFactors drw_view.viewcamtexcofac
+#endif
 
 struct ObjectMatrices {
   float4x4 drw_modelMatrix;