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, 36 insertions, 48 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_shaders.c b/source/blender/draw/engines/eevee/eevee_shaders.c
index ae5e6e94f74..4e4a2a9eb8e 100644
--- a/source/blender/draw/engines/eevee/eevee_shaders.c
+++ b/source/blender/draw/engines/eevee/eevee_shaders.c
@@ -170,6 +170,7 @@ extern char datatoc_common_math_lib_glsl[];
 extern char datatoc_common_math_geom_lib_glsl[];
 extern char datatoc_common_view_lib_glsl[];
 extern char datatoc_gpu_shader_common_obinfos_lib_glsl[];
+extern char datatoc_gpu_shader_codegen_lib_glsl[];
 
 extern char datatoc_ambient_occlusion_lib_glsl[];
 extern char datatoc_background_vert_glsl[];
@@ -178,6 +179,7 @@ extern char datatoc_bsdf_lut_frag_glsl[];
 extern char datatoc_bsdf_sampling_lib_glsl[];
 extern char datatoc_btdf_lut_frag_glsl[];
 extern char datatoc_closure_type_lib_glsl[];
+extern char datatoc_closure_eval_volume_lib_glsl[];
 extern char datatoc_common_uniforms_lib_glsl[];
 extern char datatoc_common_utiltex_lib_glsl[];
 extern char datatoc_cryptomatte_frag_glsl[];
@@ -230,6 +232,7 @@ extern char datatoc_lightprobe_planar_downsample_vert_glsl[];
 extern char datatoc_lightprobe_vert_glsl[];
 extern char datatoc_lights_lib_glsl[];
 extern char datatoc_closure_eval_lib_glsl[];
+extern char datatoc_closure_eval_surface_lib_glsl[];
 extern char datatoc_closure_eval_diffuse_lib_glsl[];
 extern char datatoc_closure_eval_glossy_lib_glsl[];
 extern char datatoc_closure_eval_refraction_lib_glsl[];
@@ -239,7 +242,6 @@ extern char datatoc_object_motion_frag_glsl[];
 extern char datatoc_object_motion_vert_glsl[];
 extern char datatoc_octahedron_lib_glsl[];
 extern char datatoc_prepass_frag_glsl[];
-extern char datatoc_prepass_vert_glsl[];
 extern char datatoc_random_lib_glsl[];
 extern char datatoc_raytrace_lib_glsl[];
 extern char datatoc_renderpass_lib_glsl[];
@@ -261,6 +263,7 @@ extern char datatoc_volumetric_lib_glsl[];
 extern char datatoc_volumetric_resolve_frag_glsl[];
 extern char datatoc_volumetric_scatter_frag_glsl[];
 extern char datatoc_volumetric_vert_glsl[];
+extern char datatoc_world_vert_glsl[];
 
 /* *********** FUNCTIONS *********** */
 
@@ -275,6 +278,7 @@ static void eevee_shader_library_ensure(void)
     DRW_SHADER_LIB_ADD(e_data.lib, common_view_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, common_uniforms_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, gpu_shader_common_obinfos_lib);
+    DRW_SHADER_LIB_ADD(e_data.lib, gpu_shader_codegen_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, random_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, renderpass_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, bsdf_common_lib);
@@ -299,6 +303,8 @@ static void eevee_shader_library_ensure(void)
     DRW_SHADER_LIB_ADD(e_data.lib, closure_eval_glossy_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, closure_eval_translucent_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, closure_eval_refraction_lib);
+    DRW_SHADER_LIB_ADD(e_data.lib, closure_eval_surface_lib);
+    DRW_SHADER_LIB_ADD(e_data.lib, closure_eval_volume_lib);
 
     e_data.surface_lit_frag = DRW_shader_library_create_shader_string(e_data.lib,
                                                                       datatoc_surface_frag_glsl);
@@ -313,6 +319,7 @@ static void eevee_shader_library_ensure(void)
 
 void EEVEE_shaders_material_shaders_init(void)
 {
+  eevee_shader_extra_init();
   eevee_shader_library_ensure();
 }
 
@@ -828,6 +835,7 @@ struct GPUShader *EEVEE_shaders_volumes_clear_sh_get()
                                                                   datatoc_volumetric_frag_glsl,
                                                                   e_data.lib,
                                                                   SHADER_DEFINES
+                                                                  "#define STANDALONE\n"
                                                                   "#define VOLUMETRICS\n"
                                                                   "#define CLEAR\n");
   }
@@ -842,6 +850,7 @@ struct GPUShader *EEVEE_shaders_volumes_scatter_sh_get()
                                                          datatoc_volumetric_scatter_frag_glsl,
                                                          e_data.lib,
                                                          SHADER_DEFINES
+                                                         "#define STANDALONE\n"
                                                          "#define VOLUMETRICS\n"
                                                          "#define VOLUME_SHADOW\n");
   }
@@ -857,6 +866,7 @@ struct GPUShader *EEVEE_shaders_volumes_scatter_with_lights_sh_get()
         datatoc_volumetric_scatter_frag_glsl,
         e_data.lib,
         SHADER_DEFINES
+        "#define STANDALONE\n"
         "#define VOLUMETRICS\n"
         "#define VOLUME_LIGHTING\n"
         "#define VOLUME_SHADOW\n");
@@ -872,7 +882,9 @@ struct GPUShader *EEVEE_shaders_volumes_integration_sh_get()
         datatoc_volumetric_geom_glsl,
         datatoc_volumetric_integration_frag_glsl,
         e_data.lib,
-        USE_VOLUME_OPTI ? "#define USE_VOLUME_OPTI\n" SHADER_DEFINES : SHADER_DEFINES);
+        USE_VOLUME_OPTI ? "#define USE_VOLUME_OPTI\n"
+                          "#define STANDALONE\n" SHADER_DEFINES :
+                          "#define STANDALONE\n" SHADER_DEFINES);
   }
   return e_data.volumetric_integration_sh;
 }
@@ -1232,7 +1244,7 @@ Material *EEVEE_material_default_glossy_get(void)
 Material *EEVEE_material_default_error_get(void)
 {
   if (!e_data.error_mat) {
-    Material *ma = BKE_id_new_nomain(ID_MA, "EEVEEE default metal");
+    Material *ma = BKE_id_new_nomain(ID_MA, "EEVEEE default error");
 
     bNodeTree *ntree = ntreeAddTree(NULL, "Shader Nodetree", ntreeType_Shader->idname);
     ma->nodetree = ntree;
@@ -1375,7 +1387,7 @@ static char *eevee_get_vert(int options)
     str = DRW_shader_library_create_shader_string(e_data.lib, datatoc_volumetric_vert_glsl);
   }
   else if ((options & (VAR_WORLD_PROBE | VAR_WORLD_BACKGROUND)) != 0) {
-    str = DRW_shader_library_create_shader_string(e_data.lib, datatoc_background_vert_glsl);
+    str = DRW_shader_library_create_shader_string(e_data.lib, datatoc_world_vert_glsl);
   }
   else {
     str = DRW_shader_library_create_shader_string(e_data.lib, datatoc_surface_vert_glsl);
@@ -1412,68 +1424,43 @@ static char *eevee_get_frag(int options)
   return str;
 }
 
-static void eevee_material_post_eval(GPUMaterial *mat,
-                                     int options,
-                                     const char **UNUSED(vert_code),
-                                     const char **geom_code,
-                                     const char **UNUSED(frag_lib),
-                                     const char **UNUSED(defines))
+static void eevee_material_post_eval(void *UNUSED(thunk),
+                                     GPUMaterial *mat,
+                                     GPUCodegenOutput *codegen)
 {
-  const bool is_hair = (options & VAR_MAT_HAIR) != 0;
-  const bool is_mesh = (options & VAR_MAT_MESH) != 0;
+  uint64_t options = GPU_material_uuid_get(mat);
 
-  /* Force geometry usage if GPU_BARYCENTRIC_DIST or GPU_BARYCENTRIC_TEXCO are used.
-   * NOTE: GPU_BARYCENTRIC_TEXCO only requires it if the shader is not drawing hairs. */
-  if (!is_hair && is_mesh && GPU_material_flag_get(mat, GPU_MATFLAG_BARYCENTRIC) &&
-      *geom_code == NULL) {
-    *geom_code = e_data.surface_geom_barycentric;
-  }
+  char *vert = eevee_get_vert(options);
+  char *geom = eevee_get_geom(options);
+  char *frag = eevee_get_frag(options);
+  char *defines = eevee_get_defines(options);
+
+  eevee_shader_material_create_info_amend(mat, codegen, frag, vert, geom, defines);
+
+  MEM_SAFE_FREE(defines);
+  MEM_SAFE_FREE(vert);
+  MEM_SAFE_FREE(geom);
+  MEM_SAFE_FREE(frag);
 }
 
 static struct GPUMaterial *eevee_material_get_ex(
-    struct Scene *scene, Material *ma, World *wo, int options, bool deferred)
+    struct Scene *UNUSED(scene), Material *ma, World *wo, int options, bool deferred)
 {
   BLI_assert(ma || wo);
   const bool is_volume = (options & VAR_MAT_VOLUME) != 0;
   const bool is_default = (options & VAR_DEFAULT) != 0;
-  const void *engine = &DRW_engine_viewport_eevee_type;
 
   GPUMaterial *mat = NULL;
+  GPUCodegenCallbackFn cbfn = &eevee_material_post_eval;
 
   if (ma) {
-    mat = DRW_shader_find_from_material(ma, engine, options, deferred);
-  }
-  else {
-    mat = DRW_shader_find_from_world(wo, engine, options, deferred);
-  }
-
-  if (mat) {
-    return mat;
-  }
-
-  char *defines = eevee_get_defines(options);
-  char *vert = eevee_get_vert(options);
-  char *geom = eevee_get_geom(options);
-  char *frag = eevee_get_frag(options);
-
-  if (ma) {
-    GPUMaterialEvalCallbackFn cbfn = &eevee_material_post_eval;
-
     bNodeTree *ntree = !is_default ? ma->nodetree : EEVEE_shader_default_surface_nodetree(ma);
-    mat = DRW_shader_create_from_material(
-        scene, ma, ntree, engine, options, is_volume, vert, geom, frag, defines, deferred, cbfn);
+    mat = DRW_shader_from_material(ma, ntree, options, is_volume, deferred, cbfn, NULL);
   }
   else {
     bNodeTree *ntree = !is_default ? wo->nodetree : EEVEE_shader_default_world_nodetree(wo);
-    mat = DRW_shader_create_from_world(
-        scene, wo, ntree, engine, options, is_volume, vert, geom, frag, defines, deferred, NULL);
+    mat = DRW_shader_from_world(wo, ntree, options, is_volume, deferred, cbfn, NULL);
   }
-
-  MEM_SAFE_FREE(defines);
-  MEM_SAFE_FREE(vert);
-  MEM_SAFE_FREE(geom);
-  MEM_SAFE_FREE(frag);
-
   return mat;
 }
 
@@ -1520,6 +1507,7 @@ struct GPUMaterial *EEVEE_material_get(
 
 void EEVEE_shaders_free(void)
 {
+  eevee_shader_extra_exit();
   MEM_SAFE_FREE(e_data.surface_prepass_frag);
   MEM_SAFE_FREE(e_data.surface_lit_frag);
   MEM_SAFE_FREE(e_data.surface_geom_barycentric);