From 64968e3618892ebac419149fa8c4198151a4e29a Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Tue, 25 Jun 2013 10:49:20 +0000
Subject: [PATCH] patch [#35830] Add Catmull-Rom spline as an option for
 lattice deformer

---
 source/blender/blenkernel/intern/key.c   | 27 ++++++++++++++++++++++++
 source/blender/makesdna/DNA_key_types.h  |  3 ++-
 source/blender/makesrna/intern/rna_key.c |  1 +
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/source/blender/blenkernel/intern/key.c b/source/blender/blenkernel/intern/key.c
index dfa5fcff94c..e141b9dbabe 100644
--- a/source/blender/blenkernel/intern/key.c
+++ b/source/blender/blenkernel/intern/key.c
@@ -289,6 +289,16 @@ void key_curve_position_weights(float t, float data[4], int type)
 		data[2] = -0.5f        * t3  + 0.5f * t2   + 0.5f * t    + 0.16666666f;
 		data[3] =  0.16666666f * t3;
 	}
+	else if (type == KEY_CATMULL_ROM) {
+		t2 = t * t;
+		t3 = t2 * t;
+		fc = 0.5f;
+
+		data[0] = -fc          * t3  + 2.0f * fc          * t2 - fc * t;
+		data[1] =  (2.0f - fc) * t3  + (fc - 3.0f)        * t2 + 1.0f;
+		data[2] =  (fc - 2.0f) * t3  + (3.0f - 2.0f * fc) * t2 + fc * t;
+		data[3] =  fc          * t3  - fc * t2;
+	}
 }
 
 /* first derivative */
@@ -319,6 +329,15 @@ void key_curve_tangent_weights(float t, float data[4], int type)
 		data[2] = -1.5f * t2  + t         + 0.5f;
 		data[3] =  0.5f * t2;
 	}
+	else if (type == KEY_CATMULL_ROM) {
+		t2 = t * t;
+		fc = 0.5f;
+
+		data[0] = -3.0f * fc          * t2  + 4.0f * fc * t                  - fc;
+		data[1] =  3.0f * (2.0f - fc) * t2  + 2.0f * (fc - 3.0f) * t;
+		data[2] =  3.0f * (fc - 2.0f) * t2  + 2.0f * (3.0f - 2.0f * fc) * t  + fc;
+		data[3] =  3.0f * fc          * t2  - 2.0f * fc * t;
+	}
 }
 
 /* second derivative */
@@ -346,6 +365,14 @@ void key_curve_normal_weights(float t, float data[4], int type)
 		data[2] = -3.0f * t  + 1.0f;
 		data[3] =  1.0f * t;
 	}
+	else if (type == KEY_CATMULL_ROM) {
+		fc = 0.5f;
+
+		data[0] = -6.0f * fc          * t  + 4.0f * fc;
+		data[1] =  6.0f * (2.0f - fc) * t  + 2.0f * (fc - 3.0f);
+		data[2] =  6.0f * (fc - 2.0f) * t  + 2.0f * (3.0f - 2.0f * fc);
+		data[3] =  6.0f * fc          * t  - 2.0f * fc;
+	}
 }
 
 static int setkeys(float fac, ListBase *lb, KeyBlock *k[], float t[4], int cycl)
diff --git a/source/blender/makesdna/DNA_key_types.h b/source/blender/makesdna/DNA_key_types.h
index 4783247420c..0a09a82b2bb 100644
--- a/source/blender/makesdna/DNA_key_types.h
+++ b/source/blender/makesdna/DNA_key_types.h
@@ -125,7 +125,8 @@ enum {
 enum {
 	KEY_LINEAR      = 0,
 	KEY_CARDINAL    = 1,
-	KEY_BSPLINE     = 2
+	KEY_BSPLINE     = 2,
+	KEY_CATMULL_ROM = 3,
 };
 
 /* KeyBlock->flag */
diff --git a/source/blender/makesrna/intern/rna_key.c b/source/blender/makesrna/intern/rna_key.c
index 3a2677c8398..49d760adb32 100644
--- a/source/blender/makesrna/intern/rna_key.c
+++ b/source/blender/makesrna/intern/rna_key.c
@@ -458,6 +458,7 @@ static char *rna_ShapeKeyPoint_path(PointerRNA *ptr)
 EnumPropertyItem keyblock_type_items[] = {
 	{KEY_LINEAR, "KEY_LINEAR", 0, "Linear", ""},
 	{KEY_CARDINAL, "KEY_CARDINAL", 0, "Cardinal", ""},
+	{KEY_CATMULL_ROM, "KEY_CATMULL_ROM", 0, "Catmull-Rom", ""},
 	{KEY_BSPLINE, "KEY_BSPLINE", 0, "BSpline", ""},
 	{0, NULL, 0, NULL, NULL}
 };