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, 6 insertions, 78 deletions

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_texture_coordinates.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_texture_coordinates.glsl
index a8ef9687b0a..a3666164cf7 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_texture_coordinates.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_texture_coordinates.glsl
@@ -1,38 +1,5 @@
-vec3 mtex_2d_mapping(vec3 vec)
-{
-  return vec3(vec.xy * 0.5 + vec2(0.5), vec.z);
-}
-
-void generated_from_orco(vec3 orco, out vec3 generated)
-{
-#ifdef VOLUMETRICS
-#  ifdef MESH_SHADER
-  generated = volumeObjectLocalCoord;
-#  else
-  generated = worldPosition;
-#  endif
-#else
-  generated = orco;
-#endif
-}
 
-void generated_texco(vec3 I, vec3 attr_orco, out vec3 generated)
-{
-  vec4 v = (ProjectionMatrix[3][3] == 0.0) ? vec4(I, 1.0) : vec4(0.0, 0.0, 1.0, 1.0);
-  vec4 co_homogeneous = (ProjectionMatrixInverse * v);
-  vec4 co = vec4(co_homogeneous.xyz / co_homogeneous.w, 0.0);
-  co.xyz = normalize(co.xyz);
-#if defined(WORLD_BACKGROUND) || defined(PROBE_CAPTURE)
-  generated = (ViewMatrixInverse * co).xyz;
-#else
-  generated_from_orco(attr_orco, generated);
-#endif
-}
-
-void node_tex_coord(vec3 I,
-                    vec3 wN,
-                    mat4 obmatinv,
-                    vec4 camerafac,
+void node_tex_coord(mat4 obmatinv,
                     vec3 attr_orco,
                     vec3 attr_uv,
                     out vec3 generated,
@@ -44,49 +11,10 @@ void node_tex_coord(vec3 I,
                     out vec3 reflection)
 {
   generated = attr_orco;
-  normal = normalize(normal_world_to_object(wN));
+  normal = normal_world_to_object(g_data.N);
   uv = attr_uv;
-  object = (obmatinv * (ViewMatrixInverse * vec4(I, 1.0))).xyz;
-  camera = vec3(I.xy, -I.z);
-  vec4 projvec = ProjectionMatrix * vec4(I, 1.0);
-  window = vec3(mtex_2d_mapping(projvec.xyz / projvec.w).xy * camerafac.xy + camerafac.zw, 0.0);
-  reflection = -reflect(cameraVec(worldPosition), normalize(wN));
-}
-
-void node_tex_coord_background(vec3 I,
-                               vec3 N,
-                               mat4 obmatinv,
-                               vec4 camerafac,
-                               vec3 attr_orco,
-                               vec3 attr_uv,
-                               out vec3 generated,
-                               out vec3 normal,
-                               out vec3 uv,
-                               out vec3 object,
-                               out vec3 camera,
-                               out vec3 window,
-                               out vec3 reflection)
-{
-  vec4 v = (ProjectionMatrix[3][3] == 0.0) ? vec4(I, 1.0) : vec4(0.0, 0.0, 1.0, 1.0);
-  vec4 co_homogeneous = (ProjectionMatrixInverse * v);
-
-  vec4 co = vec4(co_homogeneous.xyz / co_homogeneous.w, 0.0);
-
-  co = normalize(co);
-
-  vec3 coords = (ViewMatrixInverse * co).xyz;
-
-  generated = coords;
-  normal = -coords;
-  uv = vec3(attr_uv.xy, 0.0);
-  object = (obmatinv * vec4(coords, 1.0)).xyz;
-
-  camera = vec3(co.xy, -co.z);
-  window = vec3(mtex_2d_mapping(I).xy * camerafac.xy + camerafac.zw, 0.0);
-
-  reflection = -coords;
+  object = transform_point((obmatinv[3][3] == 0.0) ? ModelMatrixInverse : obmatinv, g_data.P);
+  camera = coordinate_camera(g_data.P);
+  window = coordinate_screen(g_data.P);
+  reflection = coordinate_reflect(g_data.P, g_data.N);
 }
-
-#if defined(WORLD_BACKGROUND) || (defined(PROBE_CAPTURE) && !defined(MESH_SHADER))
-#  define node_tex_coord node_tex_coord_background
-#endif