EEVEE: GLSL refactor/cleanup

- add the use of DRWShaderLibrary to EEVEE's glsl codebase to reduce code
complexity and duplication.
- split bsdf_common_lib.glsl into multiple sub library which are now shared
with other engines.
- the surface shader code is now more organised and have its own files.
- change default world to use a material nodetree and make lookdev shader
more clear.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D8306

7 files changed, 14 insertions, 46 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_cavity_lib.glsl b/source/blender/draw/engines/workbench/shaders/workbench_cavity_lib.glsl
index 722dbdd0b5e..d0d52c8485b 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_cavity_lib.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_cavity_lib.glsl
@@ -28,7 +28,7 @@ void cavity_compute(vec2 screenco,
     return;
   }
 
-  vec3 position = view_position_from_depth(screenco, depth, ViewVecs, ProjectionMatrix);
+  vec3 position = get_view_space_from_depth(screenco, depth);
   vec3 normal = workbench_normal_decode(texture(normalBuffer, screenco));
 
   vec2 jitter_co = (screenco * world_data.viewport_size.xy) * world_data.cavity_jitter_scale;
@@ -68,7 +68,7 @@ void cavity_compute(vec2 screenco,
     bool is_background = (s_depth == 1.0);
     /* This trick provide good edge effect even if no neighbor is found. */
     s_depth = (is_background) ? depth : s_depth;
-    vec3 s_pos = view_position_from_depth(uvcoords, s_depth, ViewVecs, ProjectionMatrix);
+    vec3 s_pos = get_view_space_from_depth(uvcoords, s_depth);
 
     if (is_background) {
       s_pos.z -= world_data.cavity_distance;
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl b/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
index c529f23265b..eb61edca6c7 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
@@ -67,31 +67,3 @@ void workbench_float_pair_decode(float data, out float v1, out float v2)
   v1 = float(idata & v1_mask) * (1.0 / float(v1_mask));
   v2 = float(idata >> int(ROUGHNESS_BITS)) * (1.0 / float(v2_mask));
 }
-
-vec3 view_vector_from_screen_uv(vec2 uv, vec4 viewvecs[2], mat4 proj_mat)
-{
-  if (proj_mat[3][3] == 0.0) {
-    return normalize(vec3(viewvecs[0].xy + uv * viewvecs[1].xy, 1.0));
-  }
-  else {
-    return vec3(0.0, 0.0, 1.0);
-  }
-}
-
-vec3 view_position_from_depth(vec2 uvcoords, float depth, vec4 viewvecs[2], mat4 proj_mat)
-{
-  if (proj_mat[3][3] == 0.0) {
-    /* Perspective */
-    float d = 2.0 * depth - 1.0;
-
-    float zview = -proj_mat[3][2] / (d + proj_mat[2][2]);
-
-    return zview * vec3(viewvecs[0].xy + uvcoords * viewvecs[1].xy, 1.0);
-  }
-  else {
-    /* Orthographic */
-    vec3 offset = vec3(uvcoords, depth);
-
-    return viewvecs[0].xyz + offset * viewvecs[1].xyz;
-  }
-}
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl
index f3a238fd112..6e10a656fc1 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl
@@ -14,7 +14,7 @@ out vec4 fragColor;
 void main()
 {
   /* Normal and Incident vector are in viewspace. Lighting is evaluated in viewspace. */
-  vec3 I = view_vector_from_screen_uv(uvcoordsvar.st, ViewVecs, ProjectionMatrix);
+  vec3 I = get_view_vector_from_screen_uv(uvcoordsvar.st);
   vec3 N = workbench_normal_decode(texture(normalBuffer, uvcoordsvar.st));
   vec4 mat_data = texture(materialBuffer, uvcoordsvar.st);
 
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_effect_dof_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_effect_dof_frag.glsl
index 51007a9f246..71816f6ff6e 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_effect_dof_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_effect_dof_frag.glsl
@@ -1,3 +1,6 @@
+
+#pragma BLENDER_REQUIRE(common_math_lib.glsl)
+
 /**
  * Separable Hexagonal Bokeh Blur by Colin Barré-Brisebois
  * https://colinbarrebrisebois.com/2017/04/18/hexagonal-bokeh-blur-revisited-part-1-basic-3-pass-version/
@@ -21,13 +24,6 @@ uniform sampler2D noiseTex;
 #define dof_distance dofParams.y
 #define dof_invsensorsize dofParams.z
 
-#define M_PI 3.1415926535897932 /* pi */
-
-float max_v4(vec4 v)
-{
-  return max(max(v.x, v.y), max(v.z, v.w));
-}
-
 #define weighted_sum(a, b, c, d, e, e_sum) \
   ((a)*e.x + (b)*e.y + (c)*e.z + (d)*e.w) / max(1e-6, e_sum);
 
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_transparent_accum_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_transparent_accum_frag.glsl
index ba8eeff1001..fd4d00d96dd 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_transparent_accum_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_transparent_accum_frag.glsl
@@ -57,7 +57,7 @@ void main()
 {
   /* Normal and Incident vector are in viewspace. Lighting is evaluated in viewspace. */
   vec2 uv_viewport = gl_FragCoord.xy * world_data.viewport_size_inv;
-  vec3 I = view_vector_from_screen_uv(uv_viewport, ViewVecs, ProjectionMatrix);
+  vec3 I = get_view_vector_from_screen_uv(uv_viewport);
   vec3 N = normalize(normal_interp);
 
   vec3 color = color_interp;
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
index 6ab652cbf36..aa938d80fa3 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
@@ -1,4 +1,5 @@
 
+#pragma BLENDER_REQUIRE(common_math_lib.glsl)
 #pragma BLENDER_REQUIRE(common_view_lib.glsl)
 #pragma BLENDER_REQUIRE(gpu_shader_common_obinfos_lib.glsl)
 #pragma BLENDER_REQUIRE(workbench_data_lib.glsl)
@@ -33,11 +34,6 @@ float phase_function_isotropic()
   return 1.0 / (4.0 * M_PI);
 }
 
-float max_v3(vec3 v)
-{
-  return max(v.x, max(v.y, v.z));
-}
-
 float line_unit_box_intersect_dist(vec3 lineorigin, vec3 linedirection)
 {
   /* https://seblagarde.wordpress.com/2012/09/29/image-based-lighting-approaches-and-parallax-corrected-cubemap/
@@ -194,8 +190,8 @@ void main()
 
   float depth = texelFetch(depthBuffer, ivec2(gl_FragCoord.xy), 0).r;
   float depth_end = min(depth, gl_FragCoord.z);
-  vec3 vs_ray_end = view_position_from_depth(screen_uv, depth_end, ViewVecs, ProjectionMatrix);
-  vec3 vs_ray_ori = view_position_from_depth(screen_uv, 0.0, ViewVecs, ProjectionMatrix);
+  vec3 vs_ray_end = get_view_space_from_depth(screen_uv, depth_end);
+  vec3 vs_ray_ori = get_view_space_from_depth(screen_uv, 0.0);
   vec3 vs_ray_dir = (is_persp) ? (vs_ray_end - vs_ray_ori) : vec3(0.0, 0.0, -1.0);
   vs_ray_dir /= abs(vs_ray_dir.z);
 
diff --git a/source/blender/draw/engines/workbench/workbench_shader.c b/source/blender/draw/engines/workbench/workbench_shader.c
index 835f10598d4..aab3cef00e6 100644
--- a/source/blender/draw/engines/workbench/workbench_shader.c
+++ b/source/blender/draw/engines/workbench/workbench_shader.c
@@ -28,6 +28,8 @@
 #include "workbench_engine.h"
 #include "workbench_private.h"
 
+extern char datatoc_common_math_lib_glsl[];
+extern char datatoc_common_math_geom_lib_glsl[];
 extern char datatoc_common_hair_lib_glsl[];
 extern char datatoc_common_pointcloud_lib_glsl[];
 extern char datatoc_common_view_lib_glsl[];
@@ -119,6 +121,8 @@ void workbench_shader_library_ensure(void)
   if (e_data.lib == NULL) {
     e_data.lib = DRW_shader_library_create();
     /* NOTE: Theses needs to be ordered by dependencies. */
+    DRW_SHADER_LIB_ADD(e_data.lib, common_math_lib);
+    DRW_SHADER_LIB_ADD(e_data.lib, common_math_geom_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, common_hair_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, common_view_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, common_pointcloud_lib);