Cycles: persistent images option

This option enables keeping loaded images in the memory in-between
of rendering.

Implemented by keeping render engine alive for until Render structure
is being freed.

Cycles will free all data when render finishes, optionally keeping
image manager untouched. All shaders, meshes, objects will be
re-allocated next time rendering happens.

Cycles cession and scene will be re-created from scratch if render/
scene parameters were changed.

This will also allow to keep compiled OSL shaders in memory without
need to re-compile them again.

P.S. Performance panel could be cleaned up a bit, not so much happy
     with it's vertical alignment currently but not sure how to make
     it look better.

 P.P.S. Currently the only way to free images from the device is to
       disable Persistent Images option and start rendering.

3 files changed, 13 insertions, 3 deletions

diff --git a/source/blender/render/intern/include/render_types.h b/source/blender/render/intern/include/render_types.h
index 825fe2ff4d0..6ed8d6a7b6c 100644
--- a/source/blender/render/intern/include/render_types.h
+++ b/source/blender/render/intern/include/render_types.h
@@ -59,6 +59,7 @@ struct RenderBuckets;
 struct ObjectInstanceRen;
 struct RayObject;
 struct RayFace;
+struct RenderEngine;
 struct ReportList;
 struct Main;
 
@@ -183,6 +184,9 @@ struct Render
 	
 	ListBase parts;
 	
+	/* render engine */
+	struct RenderEngine *engine;
+	
 	/* octree tables and variables for raytrace */
 	struct RayObject *raytree;
 	struct RayFace *rayfaces;
diff --git a/source/blender/render/intern/source/external_engine.c b/source/blender/render/intern/source/external_engine.c
index e2f347c05f1..736cb5de7c3 100644
--- a/source/blender/render/intern/source/external_engine.c
+++ b/source/blender/render/intern/source/external_engine.c
@@ -349,7 +349,12 @@ int RE_engine_render(Render *re, int do_all)
 	re->i.totface = re->i.totvert = re->i.totstrand = re->i.totlamp = re->i.tothalo = 0;
 
 	/* render */
-	engine = RE_engine_create(type);
+	if(!re->engine)
+		re->engine = RE_engine_create(type);
+
+	engine = re->engine;
+
+	/* TODO: actually link to a parent which shouldn't happen */
 	engine->re = re;
 
 	if (re->flag & R_ANIMATION)
@@ -389,8 +394,6 @@ int RE_engine_render(Render *re, int do_all)
 
 	render_result_free_list(&engine->fullresult, engine->fullresult.first);
 
-	RE_engine_free(engine);
-
 	if (BKE_reports_contain(re->reports, RPT_ERROR))
 		G.is_break = TRUE;
 	
diff --git a/source/blender/render/intern/source/pipeline.c b/source/blender/render/intern/source/pipeline.c
index d305ed06af1..369818d37d5 100644
--- a/source/blender/render/intern/source/pipeline.c
+++ b/source/blender/render/intern/source/pipeline.c
@@ -387,6 +387,9 @@ void RE_InitRenderCB(Render *re)
 /* only call this while you know it will remove the link too */
 void RE_FreeRender(Render *re)
 {
+	if (re->engine)
+		RE_engine_free(re->engine);
+
 	BLI_rw_mutex_end(&re->resultmutex);
 	
 	free_renderdata_tables(re);