[Bf-blender-cvs] [40177740830] temp-angavrilov-constraints: Limit Rotation: add an Euler Order option and orthogonalize the matrix.

[Alexander Gavrilov]

Commit: 401777408302c48958f3d0cd9a0afebf105f5169
Author: Alexander Gavrilov
Date:   Sun Nov 22 14:17:21 2020 +0300
Branches: temp-angavrilov-constraints
https://developer.blender.org/rB401777408302c48958f3d0cd9a0afebf105f5169

Limit Rotation: add an Euler Order option and orthogonalize the matrix.

Since Limit Rotation is based on Euler decomposition, it should allow
specifying the order to use for the same reasons as Copy Rotation does,
namely, if the bone uses Quaternion rotation for its animation channels,
there is no way to choose the order for the constraint.

In addition, add a call to orthogonalize the matrix before processing
for the same reasons as D8915, and an early exit in case no limits are
enabled for a bit of extra efficiency.

Since the constraint goes through Euler decomposition, it would remove
shear even before the change, but the rotation won't make much sense.

Differential Revision: https://developer.blender.org/D9626

===================================================================

M	release/scripts/startup/bl_ui/properties_constraint.py
M	source/blender/blenkernel/intern/constraint.c
M	source/blender/makesdna/DNA_constraint_types.h
M	source/blender/makesrna/intern/rna_constraint.c

===================================================================

diff --git a/release/scripts/startup/bl_ui/properties_constraint.py b/release/scripts/startup/bl_ui/properties_constraint.py
index e835e577953..a88def34767 100644
--- a/release/scripts/startup/bl_ui/properties_constraint.py
+++ b/release/scripts/startup/bl_ui/properties_constraint.py
@@ -245,6 +245,7 @@ class ConstraintButtonsPanel:
         sub.prop(con, "max_z", text="Max")
         row.label(icon='BLANK1')
 
+        layout.prop(con, "euler_order", text="Order")
         layout.prop(con, "use_transform_limit")
         self.space_template(layout, con, target=False, owner=True)
 
diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index 754ee896552..5c2d4831839 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -1633,10 +1633,28 @@ static void rotlimit_evaluate(bConstraint *con, bConstraintOb *cob, ListBase *UN
   float eul[3];
   float size[3];
 
+  /* This constraint is based on euler rotation math, which doesn't work well with shear.
+   * The Y axis is chosen as the main one because constraints are most commonly used on bones.
+   * This also allows using the constraint to simply remove shear. */
+  orthogonalize_m4_stable(cob->matrix, 1, false);
+
+  /* Only do the complex processing if some limits are actually enabled. */
+  if (!(data->flag & (LIMIT_XROT | LIMIT_YROT | LIMIT_ZROT))) {
+    return;
+  }
+
+  /* Select the Euler rotation order, defaulting to the owner value. */
+  short rot_order = cob->rotOrder;
+
+  if (data->euler_order != CONSTRAINT_EULER_AUTO) {
+    rot_order = data->euler_order;
+  }
+
+  /* Decompose the matrix using the specified order. */
   copy_v3_v3(loc, cob->matrix[3]);
   mat4_to_size(size, cob->matrix);
 
-  mat4_to_eulO(eul, cob->rotOrder, cob->matrix);
+  mat4_to_eulO(eul, rot_order, cob->matrix);
 
   /* constraint data uses radians internally */
 
@@ -1669,7 +1687,7 @@ static void rotlimit_evaluate(bConstraint *con, bConstraintOb *cob, ListBase *UN
     }
   }
 
-  loc_eulO_size_to_mat4(cob->matrix, loc, eul, size, cob->rotOrder);
+  loc_eulO_size_to_mat4(cob->matrix, loc, eul, size, rot_order);
 }
 
 static bConstraintTypeInfo CTI_ROTLIMIT = {
diff --git a/source/blender/makesdna/DNA_constraint_types.h b/source/blender/makesdna/DNA_constraint_types.h
index 957c52cbb73..18b6205dde6 100644
--- a/source/blender/makesdna/DNA_constraint_types.h
+++ b/source/blender/makesdna/DNA_constraint_types.h
@@ -536,6 +536,8 @@ typedef struct bRotLimitConstraint {
   float zmin, zmax;
   short flag;
   short flag2;
+  char euler_order;
+  char _pad[3];
 } bRotLimitConstraint;
 
 /* Limit Scale Constraint */
diff --git a/source/blender/makesrna/intern/rna_constraint.c b/source/blender/makesrna/intern/rna_constraint.c
index 51b6d9ad4d1..8dd5b945915 100644
--- a/source/blender/makesrna/intern/rna_constraint.c
+++ b/source/blender/makesrna/intern/rna_constraint.c
@@ -2603,6 +2603,12 @@ static void rna_def_constraint_rotation_limit(BlenderRNA *brna)
   RNA_def_property_ui_text(prop, "Maximum Z", "Highest Z value to allow");
   RNA_def_property_update(prop, NC_OBJECT | ND_CONSTRAINT, "rna_Constraint_update");
 
+  prop = RNA_def_property(srna, "euler_order", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "euler_order");
+  RNA_def_property_enum_items(prop, euler_order_items);
+  RNA_def_property_ui_text(prop, "Euler Order", "Explicitly specify the euler rotation order");
+  RNA_def_property_update(prop, NC_OBJECT | ND_CONSTRAINT, "rna_Constraint_update");
+
   prop = RNA_def_property(srna, "use_transform_limit", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_sdna(prop, NULL, "flag2", LIMIT_TRANSFORM);
   RNA_def_property_ui_text(