1 files changed, 30 insertions, 0 deletions
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_matcap_lib.glsl b/source/blender/draw/engines/workbench/shaders/workbench_matcap_lib.glsl
new file mode 100644
index 00000000000..2d18cc1b014
--- /dev/null
+++ b/source/blender/draw/engines/workbench/shaders/workbench_matcap_lib.glsl
@@ -0,0 +1,30 @@
+
+#pragma BLENDER_REQUIRE(workbench_data_lib.glsl)
+
+vec2 matcap_uv_compute(vec3 I, vec3 N, bool flipped)
+{
+  /* Quick creation of an orthonormal basis */
+  float a = 1.0 / (1.0 + I.z);
+  float b = -I.x * I.y * a;
+  vec3 b1 = vec3(1.0 - I.x * I.x * a, b, -I.x);
+  vec3 b2 = vec3(b, 1.0 - I.y * I.y * a, -I.y);
+  vec2 matcap_uv = vec2(dot(b1, N), dot(b2, N));
+  if (flipped) {
+    matcap_uv.x = -matcap_uv.x;
+  }
+  return matcap_uv * 0.496 + 0.5;
+}
+
+uniform sampler2D matcapDiffuseImage;
+uniform sampler2D matcapSpecularImage;
+
+vec3 get_matcap_lighting(vec3 base_color, vec3 N, vec3 I)
+{
+  bool flipped = world_data.matcap_orientation != 0;
+  vec2 uv = matcap_uv_compute(I, N, flipped);
+
+  vec3 diffuse = textureLod(matcapDiffuseImage, uv, 0.0).rgb;
+  vec3 specular = textureLod(matcapSpecularImage, uv, 0.0).rgb;
+
+  return diffuse * base_color + specular * float(world_data.use_specular);
+}