Fix T50736: Zero streaks in Glare node.

Please never, ever use same DNA var for two different things. Even worse
if they do not have same type and ranges!

This is only ensuring issues (as described in report, but also if
animating both RNA props using same DNA var... yuck).

And we were not even saving any byte in DNA, could reuse some padding
there to store the two new needed vars (yes, two, since we cannot re-use
existing one if we want to keep backward *and* forward compatibility).

7 files changed, 58 insertions, 14 deletions

diff --git a/source/blender/blenloader/intern/versioning_270.c b/source/blender/blenloader/intern/versioning_270.c
index 6235ebf28ee..7106cf60721 100644
--- a/source/blender/blenloader/intern/versioning_270.c
+++ b/source/blender/blenloader/intern/versioning_270.c
@@ -1575,6 +1575,29 @@ void blo_do_versions_270(FileData *fd, Library *UNUSED(lib), Main *main)
 			}
 		}
 
+		/* Fix for T50736, Glare comp node using same var for two different things. */
+		if (!DNA_struct_elem_find(fd->filesdna, "NodeGlare", "char", "star_45")) {
+			FOREACH_NODETREE(main, ntree, id) {
+				if (ntree->type == NTREE_COMPOSIT) {
+					ntreeSetTypes(NULL, ntree);
+					for (bNode *node = ntree->nodes.first; node; node = node->next) {
+						if (node->type == CMP_NODE_GLARE) {
+							NodeGlare *ndg = node->storage;
+							switch (ndg->type) {
+								case 2:  /* Grrrr! magic numbers :( */
+									ndg->streaks = ndg->angle;
+									break;
+								case 0:
+									ndg->star_45 = ndg->angle != 0;
+									break;
+								default:
+									break;
+							}
+						}
+					}
+				}
+			} FOREACH_NODETREE_END
+		}
 	}
 }
 
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index 998d4161c2f..38a032f4907 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -1026,6 +1026,25 @@ static void write_nodetree(WriteData *wd, bNodeTree *ntree)
 			{
 				/* pass */
 			}
+			else if ((ntree->type == NTREE_COMPOSIT) && (node->type == CMP_NODE_GLARE)) {
+				/* Simple forward compat for fix for T50736.
+				 * Not ideal (there is no ideal solution here), but should do for now. */
+				NodeGlare *ndg = node->storage;
+				/* Not in undo case. */
+				if (!wd->current) {
+					switch (ndg->type) {
+						case 2:  /* Grrrr! magic numbers :( */
+							ndg->angle = ndg->streaks;
+							break;
+						case 0:
+							ndg->angle = ndg->star_45;
+							break;
+						default:
+							break;
+					}
+				}
+				writestruct_id(wd, DATA, node->typeinfo->storagename, 1, node->storage);
+			}
 			else {
 				writestruct_id(wd, DATA, node->typeinfo->storagename, 1, node->storage);
 			}
diff --git a/source/blender/compositor/operations/COM_GlareSimpleStarOperation.cpp b/source/blender/compositor/operations/COM_GlareSimpleStarOperation.cpp
index 957ac5af748..57aa3a1bac2 100644
--- a/source/blender/compositor/operations/COM_GlareSimpleStarOperation.cpp
+++ b/source/blender/compositor/operations/COM_GlareSimpleStarOperation.cpp
@@ -44,18 +44,18 @@ void GlareSimpleStarOperation::generateGlare(float *data, MemoryBuffer *inputTil
 				xp = x + i;
 				tbuf1->read(c, x, y);
 				mul_v3_fl(c, f1);
-				tbuf1->read(tc, (settings->angle ? xm : x), ym);
+				tbuf1->read(tc, (settings->star_45 ? xm : x), ym);
 				madd_v3_v3fl(c, tc, f2);
-				tbuf1->read(tc, (settings->angle ? xp : x), yp);
+				tbuf1->read(tc, (settings->star_45 ? xp : x), yp);
 				madd_v3_v3fl(c, tc, f2);
 				c[3] = 1.0f;
 				tbuf1->writePixel(x, y, c);
 
 				tbuf2->read(c, x, y);
 				mul_v3_fl(c, f1);
-				tbuf2->read(tc, xm, (settings->angle ? yp : y));
+				tbuf2->read(tc, xm, (settings->star_45 ? yp : y));
 				madd_v3_v3fl(c, tc, f2);
-				tbuf2->read(tc, xp, (settings->angle ? ym : y));
+				tbuf2->read(tc, xp, (settings->star_45 ? ym : y));
 				madd_v3_v3fl(c, tc, f2);
 				c[3] = 1.0f;
 				tbuf2->writePixel(x, y, c);
@@ -73,18 +73,18 @@ void GlareSimpleStarOperation::generateGlare(float *data, MemoryBuffer *inputTil
 				xp = x + i;
 				tbuf1->read(c, x, y);
 				mul_v3_fl(c, f1);
-				tbuf1->read(tc, (settings->angle ? xm : x), ym);
+				tbuf1->read(tc, (settings->star_45 ? xm : x), ym);
 				madd_v3_v3fl(c, tc, f2);
-				tbuf1->read(tc, (settings->angle ? xp : x), yp);
+				tbuf1->read(tc, (settings->star_45 ? xp : x), yp);
 				madd_v3_v3fl(c, tc, f2);
 				c[3] = 1.0f;
 				tbuf1->writePixel(x, y, c);
 
 				tbuf2->read(c, x, y);
 				mul_v3_fl(c, f1);
-				tbuf2->read(tc, xm, (settings->angle ? yp : y));
+				tbuf2->read(tc, xm, (settings->star_45 ? yp : y));
 				madd_v3_v3fl(c, tc, f2);
-				tbuf2->read(tc, xp, (settings->angle ? ym : y));
+				tbuf2->read(tc, xp, (settings->star_45 ? ym : y));
 				madd_v3_v3fl(c, tc, f2);
 				c[3] = 1.0f;
 				tbuf2->writePixel(x, y, c);
diff --git a/source/blender/compositor/operations/COM_GlareStreaksOperation.cpp b/source/blender/compositor/operations/COM_GlareStreaksOperation.cpp
index da6076337b4..535f2952e5d 100644
--- a/source/blender/compositor/operations/COM_GlareStreaksOperation.cpp
+++ b/source/blender/compositor/operations/COM_GlareStreaksOperation.cpp
@@ -28,7 +28,7 @@ void GlareStreaksOperation::generateGlare(float *data, MemoryBuffer *inputTile,
 	int x, y, n;
 	unsigned int nump = 0;
 	float c1[4], c2[4], c3[4], c4[4];
-	float a, ang = DEG2RADF(360.0f) / (float)settings->angle;
+	float a, ang = DEG2RADF(360.0f) / (float)settings->streaks;
 
 	int size = inputTile->getWidth() * inputTile->getHeight();
 	int size4 = size * 4;
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index fd601e55550..47677e50451 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -668,7 +668,8 @@ typedef struct NodeScriptDict {
 /* qdn: glare node */
 typedef struct NodeGlare {
 	char quality, type, iter;
-	char angle, pad_c1, size, pad[2];
+	/* XXX angle is only kept for backward/forward compatibility, was used for two different things, see T50736. */
+	char angle DNA_DEPRECATED, pad_c1, size, star_45, streaks;
 	float colmod, mix, threshold, fade;
 	float angle_ofs, pad_f1;
 } NodeGlare;
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index b35142f2a58..784004182dd 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -5721,8 +5721,8 @@ static void def_cmp_glare(StructRNA *srna)
 	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 	
 	prop = RNA_def_property(srna, "streaks", PROP_INT, PROP_NONE);
-	RNA_def_property_int_sdna(prop, NULL, "angle");
-	RNA_def_property_range(prop, 2, 16);
+	RNA_def_property_int_sdna(prop, NULL, "streaks");
+	RNA_def_property_range(prop, 1, 16);
 	RNA_def_property_ui_text(prop, "Streaks", "Total number of streaks");
 	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 	
@@ -5739,7 +5739,7 @@ static void def_cmp_glare(StructRNA *srna)
 	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 	
 	prop = RNA_def_property(srna, "use_rotate_45", PROP_BOOLEAN, PROP_NONE);
-	RNA_def_property_boolean_sdna(prop, NULL, "angle", 0);
+	RNA_def_property_boolean_sdna(prop, NULL, "star_45", 0);
 	RNA_def_property_ui_text(prop, "Rotate 45", "Simple star filter: add 45 degree rotation offset");
 	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 	
diff --git a/source/blender/nodes/composite/nodes/node_composite_glare.c b/source/blender/nodes/composite/nodes/node_composite_glare.c
index c512ea49586..76020e55463 100644
--- a/source/blender/nodes/composite/nodes/node_composite_glare.c
+++ b/source/blender/nodes/composite/nodes/node_composite_glare.c
@@ -50,7 +50,8 @@ static void node_composit_init_glare(bNodeTree *UNUSED(ntree), bNode *node)
 	ndg->colmod = 0.25;
 	ndg->mix = 0;
 	ndg->threshold = 1;
-	ndg->angle = 4;
+	ndg->star_45 = true;
+	ndg->streaks = 4;
 	ndg->angle_ofs = 0.0f;
 	ndg->fade = 0.9;
 	ndg->size = 8;