1 files changed, 46 insertions, 0 deletions
diff --git a/source/blender/draw/intern/shaders/draw_visibility_comp.glsl b/source/blender/draw/intern/shaders/draw_visibility_comp.glsl
new file mode 100644
index 00000000000..86add2d1fe2
--- /dev/null
+++ b/source/blender/draw/intern/shaders/draw_visibility_comp.glsl
@@ -0,0 +1,46 @@
+
+/**
+ * Compute visibility of each resource bounds for a given view.
+ */
+/* TODO(fclem): This could be augmented by a 2 pass occlusion culling system. */
+
+#pragma BLENDER_REQUIRE(common_math_lib.glsl)
+#pragma BLENDER_REQUIRE(common_intersect_lib.glsl)
+
+shared uint shared_result;
+
+void mask_visibility_bit()
+{
+  uint bit = 1u << gl_LocalInvocationID.x;
+  atomicAnd(visibility_buf[gl_WorkGroupID.x], ~bit);
+}
+
+void main()
+{
+  if (gl_GlobalInvocationID.x >= resource_len) {
+    return;
+  }
+
+  ObjectBounds bounds = bounds_buf[gl_GlobalInvocationID.x];
+
+  if (bounds.bounding_sphere.w != -1.0) {
+    IsectBox box = isect_data_setup(bounds.bounding_corners[0].xyz,
+                                    bounds.bounding_corners[1].xyz,
+                                    bounds.bounding_corners[2].xyz,
+                                    bounds.bounding_corners[3].xyz);
+    Sphere bounding_sphere = Sphere(bounds.bounding_sphere.xyz, bounds.bounding_sphere.w);
+    Sphere inscribed_sphere = Sphere(bounds.bounding_sphere.xyz, bounds._inner_sphere_radius);
+
+    if (intersect_view(inscribed_sphere) == true) {
+      /* Visible. */
+    }
+    else if (intersect_view(bounding_sphere) == false) {
+      /* Not visible. */
+      mask_visibility_bit();
+    }
+    else if (intersect_view(box) == false) {
+      /* Not visible. */
+      mask_visibility_bit();
+    }
+  }
+}