Improvements and fixes to Cycles metadata

This is a request by the studio here to make it possible to see how
many samples were used to render a specific shot or a frame. It is a
bit more tricky than simply stamping number of samples from a scene
since rendering is happening in multiple ranges of samples.

This change makes it so Cycles saves configured number of samples for
the specific view layer, and also stores start sample and number of
samples when rendering only a subrange of all samples.

The format used is "cycles.<view_layer_name>.><field>", which allows
to have information about all layers in a multi-layer EXR file.

Ideally we can store simplified "cycles.<field>" if we know that there
is only one render layer in the file, but detecting this is somewhat
tricky since Cycles operates on an evaluated scene which always have
single view layer.

The metadata is shown in the Metadata panels for clip, image and
sequencer spaces.

Example screenshot which shows the metadata:

{F6527727}

Reviewers: brecht

Reviewed By: brecht

Subscribers: fsiddi

Differential Revision: https://developer.blender.org/D4311

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/editors/include/ED_screen.h b/source/blender/editors/include/ED_screen.h
index e3146668571..b5ea993900c 100644
--- a/source/blender/editors/include/ED_screen.h
+++ b/source/blender/editors/include/ED_screen.h
@@ -47,6 +47,7 @@ struct bContext;
 struct bScreen;
 struct rcti;
 struct uiBlock;
+struct uiLayout;
 struct wmEvent;
 struct wmKeyConfig;
 struct wmMsgBus;
@@ -98,6 +99,7 @@ void    ED_region_visibility_change_update(struct bContext *C, struct ARegion *a
 void    ED_region_info_draw(struct ARegion *ar, const char *text, float fill_color[4], const bool full_redraw);
 void    ED_region_info_draw_multiline(ARegion *ar, const char *text_array[], float fill_color[4], const bool full_redraw);
 void    ED_region_image_metadata_draw(int x, int y, struct ImBuf *ibuf, const rctf *frame, float zoomx, float zoomy);
+void    ED_region_image_metadata_panel_draw(struct ImBuf *ibuf, struct uiLayout *layout);
 void    ED_region_grid_draw(struct ARegion *ar, float zoomx, float zoomy);
 float	ED_region_blend_alpha(struct ARegion *ar);
 void	ED_region_visible_rect(struct ARegion *ar, struct rcti *rect);