1 files changed, 129 insertions, 0 deletions
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_prepass_hair_vert.glsl b/source/blender/draw/engines/workbench/shaders/workbench_prepass_hair_vert.glsl
new file mode 100644
index 00000000000..4252c20a551
--- /dev/null
+++ b/source/blender/draw/engines/workbench/shaders/workbench_prepass_hair_vert.glsl
@@ -0,0 +1,129 @@
+
+#ifndef HAIR_SHADER
+in vec3 pos;
+in vec3 nor;
+in vec2 au; /* active texture layer */
+#  ifdef V3D_SHADING_VERTEX_COLOR
+in vec4 ac; /* active color */
+#  endif
+#  define uv au
+#else /* HAIR_SHADER */
+
+#  ifdef V3D_SHADING_TEXTURE_COLOR
+uniform samplerBuffer au; /* active texture layer */
+#  endif
+#  ifdef V3D_SHADING_VERTEX_COLOR
+uniform samplerBuffer ac; /* active color layer */
+#  endif
+
+flat out float hair_rand;
+#endif /* HAIR_SHADER */
+
+#ifdef NORMAL_VIEWPORT_PASS_ENABLED
+out vec3 normal_viewport;
+#endif
+
+#ifdef V3D_SHADING_TEXTURE_COLOR
+out vec2 uv_interp;
+#endif
+#ifdef V3D_SHADING_VERTEX_COLOR
+out vec3 vertexColor;
+#endif
+
+#ifdef OBJECT_ID_PASS_ENABLED
+RESOURCE_ID_VARYING
+#endif
+
+/* From http://libnoise.sourceforge.net/noisegen/index.html */
+float integer_noise(int n)
+{
+  n = (n >> 13) ^ n;
+  int nn = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff;
+  return (float(nn) / 1073741824.0);
+}
+
+vec3 workbench_hair_hair_normal(vec3 tan, vec3 binor, float rand)
+{
+  /* To "simulate" anisotropic shading, randomize hair normal per strand. */
+  vec3 nor = cross(tan, binor);
+  nor = normalize(mix(nor, -tan, rand * 0.1));
+  float cos_theta = (rand * 2.0 - 1.0) * 0.2;
+  float sin_theta = sqrt(max(0.0, 1.0 - cos_theta * cos_theta));
+  nor = nor * sin_theta + binor * cos_theta;
+  return nor;
+}
+
+void main()
+{
+#ifdef HAIR_SHADER
+#  ifdef V3D_SHADING_TEXTURE_COLOR
+  vec2 uv = hair_get_customdata_vec2(au);
+#  endif
+  float time, thick_time, thickness;
+  vec3 world_pos, tan, binor;
+  hair_get_pos_tan_binor_time((ProjectionMatrix[3][3] == 0.0),
+                              ModelMatrixInverse,
+                              ViewMatrixInverse[3].xyz,
+                              ViewMatrixInverse[2].xyz,
+                              world_pos,
+                              tan,
+                              binor,
+                              time,
+                              thickness,
+                              thick_time);
+
+  hair_rand = integer_noise(hair_get_strand_id());
+  vec3 nor = workbench_hair_hair_normal(tan, binor, hair_rand);
+#else
+  vec3 world_pos = point_object_to_world(pos);
+#endif
+  gl_Position = point_world_to_ndc(world_pos);
+
+#ifdef V3D_SHADING_TEXTURE_COLOR
+  uv_interp = uv;
+#endif
+
+#ifdef V3D_SHADING_VERTEX_COLOR
+#  ifndef HAIR_SHADER
+  vertexColor = ac.rgb;
+#  else
+  vertexColor = hair_get_customdata_vec4(ac).rgb;
+#  endif
+#endif
+
+#ifdef NORMAL_VIEWPORT_PASS_ENABLED
+#  ifndef HAIR_SHADER
+  normal_viewport = normal_object_to_view(nor);
+  normal_viewport = normalize(normal_viewport);
+#  else
+  normal_viewport = normal_world_to_view(nor);
+#  endif
+#endif
+
+#ifdef OBJECT_ID_PASS_ENABLED
+  PASS_RESOURCE_ID
+#endif
+
+#ifdef USE_WORLD_CLIP_PLANES
+  world_clip_planes_calc_clip_distance(world_pos);
+#endif
+
+#ifdef HAIR_SHADER
+  /* Add some variation to the hairs to avoid uniform look. */
+  float hair_variation = hair_rand * 0.1;
+  color = clamp(color - hair_variation, 0.0, 1.0);
+  metallic = clamp(materialColorAndMetal.a - hair_variation, 0.0, 1.0);
+  roughness = clamp(materialRoughness - hair_variation, 0.0, 1.0);
+#endif
+
+#ifdef V3D_LIGHTING_MATCAP
+  /* Encode front facing in metallic channel. */
+  metallic = float(gl_FrontFacing);
+  roughness = 0.0;
+#else
+  metallic = materialColorAndMetal.a;
+  roughness = materialRoughness;
+#endif
+
+  workbench_float_pair_encode(roughness, metallic)
+}