Cycles: Display RenderPass in Viewport

This change allows the user to select a renderpass in the 3d viewport.

Added support for external renderers to extend the `View3DShading` struct.
This way Blender doesn't need to know the features an external render engine wants to support.
Note that the View3DShading is also available in the scene->display.shading; although this is
supported, it does not make sense for render engines to put something here as it is really
scene/workbench related.

Currently cycles assumes that it always needs to calculate the combined pass; it ignores the
`pass_flag` in KernelFilm. We could optimize this but that was not in scope of this change

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D5689

1 files changed, 10 insertions, 0 deletions

diff --git a/intern/cycles/blender/blender_viewport.h b/intern/cycles/blender/blender_viewport.h
index 6b2f8ea4215..564c4f2b210 100644
--- a/intern/cycles/blender/blender_viewport.h
+++ b/intern/cycles/blender/blender_viewport.h
@@ -22,6 +22,7 @@
 #include "RNA_access.h"
 #include "RNA_blender_cpp.h"
 
+#include "render/film.h"
 #include "util/util_param.h"
 
 CCL_NAMESPACE_BEGIN
@@ -41,8 +42,17 @@ class BlenderViewportParameters {
   const bool modified(const BlenderViewportParameters &other) const;
   const bool custom_viewport_parameters() const;
   friend class BlenderSync;
+
+ public:
+  /* Retrieve the render pass that needs to be displayed on the given `SpaceView3D`
+   * When the `b_v3d` parameter is not given `PASS_NONE` will be returned. */
+  static PassType get_viewport_display_render_pass(BL::SpaceView3D &b_v3d);
 };
 
+PassType update_viewport_display_passes(BL::SpaceView3D &b_v3d,
+                                        vector<Pass> &passes,
+                                        bool reset_passes);
+
 CCL_NAMESPACE_END
 
 #endif