Render API/Cycles: Identify Render Passes by their name instead of a type flag

Previously, every RenderPass would have a bitfield that specified its type. That limits the number of passes to 32, which was reached a while ago.
However, most of the code already supported arbitrary RenderPasses since they were also used to store Multilayer EXR images.
Therefore, this commit completely removes the passflag from RenderPass and changes all code to use the unique pass name for identification.
Since Blender Internal relies on hardcoded passes and to preserve compatibility, 32 pass names are reserved for the old hardcoded passes.

To support these arbitrary passes, the Render Result compositor node now adds dynamic sockets. For compatibility, the old hardcoded sockets are always stored and just hidden when the corresponding pass isn't available.

To use these changes, the Render Engine API now includes a function that allows render engines to add arbitrary passes to the render result. To be able to add options for these passes, addons can now add their own properties to SceneRenderLayers.
To keep the compositor input node updated, render engine plugins have to implement a callback that registers all the passes that will be generated.

From a user perspective, nothing should change with this commit.

Differential Revision: https://developer.blender.org/D2443

Differential Revision: https://developer.blender.org/D2444

4 files changed, 13 insertions, 9 deletions

diff --git a/source/blender/blenkernel/BKE_blender_version.h b/source/blender/blenkernel/BKE_blender_version.h
index 4f4787f9da5..207631d36bd 100644
--- a/source/blender/blenkernel/BKE_blender_version.h
+++ b/source/blender/blenkernel/BKE_blender_version.h
@@ -28,7 +28,7 @@
  * and keep comment above the defines.
  * Use STRINGIFY() rather than defining with quotes */
 #define BLENDER_VERSION         278
-#define BLENDER_SUBVERSION      4
+#define BLENDER_SUBVERSION      5
 /* Several breakages with 270, e.g. constraint deg vs rad */
 #define BLENDER_MINVERSION      270
 #define BLENDER_MINSUBVERSION   6
diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 7544e8f5b3e..41028c73014 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -973,7 +973,8 @@ void ntreeCompositExecTree(struct Scene *scene, struct bNodeTree *ntree, struct
 void ntreeCompositTagRender(struct Scene *sce);
 int ntreeCompositTagAnimated(struct bNodeTree *ntree);
 void ntreeCompositTagGenerators(struct bNodeTree *ntree);
-void ntreeCompositForceHidden(struct bNodeTree *ntree);
+void ntreeCompositUpdateRLayers(struct bNodeTree *ntree);
+void ntreeCompositRegisterPass(struct bNodeTree *ntree, struct Scene *scene, struct SceneRenderLayer *srl, const char *name, int type);
 void ntreeCompositClearTags(struct bNodeTree *ntree);
 
 struct bNodeSocket *ntreeCompositOutputFileAddSocket(struct bNodeTree *ntree, struct bNode *node,
diff --git a/source/blender/blenkernel/intern/image.c b/source/blender/blenkernel/intern/image.c
index 8a01e120d6d..2db13f9c778 100644
--- a/source/blender/blenkernel/intern/image.c
+++ b/source/blender/blenkernel/intern/image.c
@@ -2739,7 +2739,6 @@ void BKE_image_signal(Image *ima, ImageUser *iuser, int signal)
 	}
 }
 
-#define PASSTYPE_UNSET -1
 /* return renderpass for a given pass index and active view */
 /* fallback to available if there are missing passes for active view */
 static RenderPass *image_render_pass_get(RenderLayer *rl, const int pass, const int view, int *r_passindex)
@@ -2748,7 +2747,7 @@ static RenderPass *image_render_pass_get(RenderLayer *rl, const int pass, const
 	RenderPass *rpass;
 
 	int rp_index = 0;
-	int rp_passtype = PASSTYPE_UNSET;
+	const char *rp_name = "";
 
 	for (rpass = rl->passes.first; rpass; rpass = rpass->next, rp_index++) {
 		if (rp_index == pass) {
@@ -2758,12 +2757,12 @@ static RenderPass *image_render_pass_get(RenderLayer *rl, const int pass, const
 				break;
 			}
 			else {
-				rp_passtype = rpass->passtype;
+				rp_name = rpass->name;
 			}
 		}
 		/* multiview */
-		else if ((rp_passtype != PASSTYPE_UNSET) &&
-		         (rpass->passtype == rp_passtype) &&
+		else if (rp_name[0] &&
+		         STREQ(rpass->name, rp_name) &&
 		         (rpass->view_id == view))
 		{
 			rpass_ret = rpass;
@@ -2783,7 +2782,6 @@ static RenderPass *image_render_pass_get(RenderLayer *rl, const int pass, const
 
 	return rpass_ret;
 }
-#undef PASSTYPE_UNSET
 
 /* if layer or pass changes, we need an index for the imbufs list */
 /* note it is called for rendered results, but it doesnt use the index! */
@@ -3753,7 +3751,7 @@ static ImBuf *image_get_render_result(Image *ima, ImageUser *iuser, void **r_loc
 			}
 
 			for (rpass = rl->passes.first; rpass; rpass = rpass->next)
-				if (rpass->passtype == SCE_PASS_Z)
+				if (STREQ(rpass->name, RE_PASSNAME_Z) && rpass->view_id == actview)
 					rectz = rpass->rect;
 		}
 	}
diff --git a/source/blender/blenkernel/intern/scene.c b/source/blender/blenkernel/intern/scene.c
index 906fa0134a0..559531a3d8a 100644
--- a/source/blender/blenkernel/intern/scene.c
+++ b/source/blender/blenkernel/intern/scene.c
@@ -2063,6 +2063,11 @@ bool BKE_scene_remove_render_layer(Main *bmain, Scene *scene, SceneRenderLayer *
 
 	BKE_freestyle_config_free(&srl->freestyleConfig);
 
+	if (srl->prop) {
+		IDP_FreeProperty(srl->prop);
+		MEM_freeN(srl->prop);
+	}
+
 	BLI_remlink(&scene->r.layers, srl);
 	MEM_freeN(srl);