Add render result caching.

Simply add an option to render settings to save an EXR cache,
just when the render is finished. Also changed RE_ReadRenderResult() to read
cache instead of temp sample files (those are fully volatile now anyway).

Path to save cached render results is an UserPreferences setting.

Also added 'Reload render' feature to the Image Editor (so one can now re-open a blend,
and in an Image Editor hit ctrl-R to (try to) reload last render from cache).

Reviewers: campbellbarton, sergey

Differential Revision: https://developer.blender.org/D553

2 files changed, 3 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index c95cdb5c1f8..6b1cad120a7 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -1377,6 +1377,7 @@ typedef struct Scene {
 /* #define R_RECURS_PROTECTION	0x20000 */
 #define R_TEXNODE_PREVIEW	0x40000
 #define R_VIEWPORT_PREVIEW	0x80000
+#define R_EXR_CACHE_FILE	0x100000
 
 /* r->stamp */
 #define R_STAMP_TIME 	0x0001
diff --git a/source/blender/makesdna/DNA_userdef_types.h b/source/blender/makesdna/DNA_userdef_types.h
index 987985f0ba7..cb2341b0b7f 100644
--- a/source/blender/makesdna/DNA_userdef_types.h
+++ b/source/blender/makesdna/DNA_userdef_types.h
@@ -422,6 +422,8 @@ typedef struct UserDef {
 	char tempdir[768];	/* FILE_MAXDIR length */
 	char fontdir[768];
 	char renderdir[1024]; /* FILE_MAX length */
+	/* EXR cache path */
+	char render_cachedir[768];  /* 768 = FILE_MAXDIR */
 	char textudir[768];
 	char pythondir[768];
 	char sounddir[768];