GPU: Split gpu_shader_material into multiple files.

This patch continue the efforts to split the `gpu_shader_material` file
started in D5569.

Dependency resolution is now recursive. Each shading node gets its own
file. Additionally, some utility files are added to be shared between
files, like `math_util`, `color_util`, and `hash`. Some files are always
included because they may be used in the execution function, like
`world_normals`.

Some glsl functions appeared to be unused, so they were removed, like
`output_node`, `bits_to_01`, and `exp_blender`. Other functions have
been renamed to be more general and get used as utils, like `texco_norm`
which became `vector_normalize`.

A lot of the opengl tests fails, but those same tests also fail in
master, so this is probably unrelated to this patch.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D5616

1 files changed, 16 insertions, 0 deletions

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_refraction.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_refraction.glsl
new file mode 100644
index 00000000000..04394a9420b
--- /dev/null
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_refraction.glsl
@@ -0,0 +1,16 @@
+#ifndef VOLUMETRICS
+void node_bsdf_refraction(vec4 color, float roughness, float ior, vec3 N, out Closure result)
+{
+  N = normalize(N);
+  vec3 out_refr;
+  color.rgb *= (refractionDepth > 0.0) ? color.rgb : vec3(1.0); /* Simulate 2 absorption event. */
+  eevee_closure_refraction(N, roughness, ior, out_refr);
+  vec3 vN = mat3(ViewMatrix) * N;
+  result = CLOSURE_DEFAULT;
+  result.ssr_normal = normal_encode(vN, viewCameraVec);
+  result.radiance = out_refr * color.rgb;
+}
+#else
+/* Stub refraction because it is not compatible with volumetrics. */
+#  define node_bsdf_refraction
+#endif