From 02acfdab9eeb01f0394f5428038d39db54096401 Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Wed, 4 Feb 2015 05:35:09 +1100
Subject: [PATCH] Add inverse-square blending for PET and warp

Similar to 'Root' but without noticeable spike/pinch in the center.
---
 source/blender/editors/transform/transform_generics.c | 6 ++++++
 source/blender/makesdna/DNA_modifier_types.h          | 1 +
 source/blender/makesdna/DNA_scene_types.h             | 3 ++-
 source/blender/makesrna/intern/rna_modifier.c         | 1 +
 source/blender/makesrna/intern/rna_scene.c            | 1 +
 source/blender/modifiers/intern/MOD_warp.c            | 3 +++
 6 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index fcf789546e8..903b3f124ee 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -1937,6 +1937,9 @@ void calculatePropRatio(TransInfo *t)
 					case PROP_RANDOM:
 						td->factor = BLI_frand() * dist;
 						break;
+					case PROP_INVSQUARE:
+						td->factor = dist * (2.0f - dist);
+						break;
 					default:
 						td->factor = 1;
 						break;
@@ -1965,6 +1968,9 @@ void calculatePropRatio(TransInfo *t)
 			case PROP_RANDOM:
 				strcpy(t->proptext, IFACE_("(Random)"));
 				break;
+			case PROP_INVSQUARE:
+				strcpy(t->proptext, IFACE_("(InvSquare)"));
+				break;
 			default:
 				t->proptext[0] = '\0';
 				break;
diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index 43d7b45675c..2d8c3b23da7 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -978,6 +978,7 @@ typedef enum {
 	eWarp_Falloff_Linear = 5, /* PROP_LIN */
 	eWarp_Falloff_Const  = 6, /* PROP_CONST */
 	eWarp_Falloff_Sphere = 7, /* PROP_SPHERE */
+	eWarp_Falloff_InvSquare = 8, /* PROP_INVSQUARE */
 	/* PROP_RANDOM not used */
 } WarpModifierFalloff;
 
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index fabfa7653f2..9ac506696ad 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -1625,7 +1625,8 @@ extern const char *RE_engine_id_CYCLES;
 #define PROP_LIN               4
 #define PROP_CONST             5
 #define PROP_RANDOM            6
-#define PROP_MODE_MAX          7
+#define PROP_INVSQUARE         7
+#define PROP_MODE_MAX          8
 
 /* toolsettings->proportional */
 #define PROP_EDIT_OFF			0
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index a7e0ed27299..12b6d74e4a5 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -1117,6 +1117,7 @@ static void rna_def_modifier_warp(BlenderRNA *brna)
 		{eWarp_Falloff_Smooth,  "SMOOTH", ICON_SMOOTHCURVE, "Smooth", ""},
 		{eWarp_Falloff_Sphere,  "SPHERE", ICON_SPHERECURVE, "Sphere", ""},
 		{eWarp_Falloff_Root,    "ROOT", ICON_ROOTCURVE, "Root", ""},
+		{eWarp_Falloff_InvSquare, "INVERSE_SQUARE", ICON_ROOTCURVE, "Inverse Square", ""},
 		{eWarp_Falloff_Sharp,   "SHARP", ICON_SHARPCURVE, "Sharp", ""},
 		{eWarp_Falloff_Linear,  "LINEAR", ICON_LINCURVE, "Linear", ""},
 		{eWarp_Falloff_Const,   "CONSTANT", ICON_NOCURVE, "Constant", ""},
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index e830e86a573..7ebbf0b132d 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -112,6 +112,7 @@ EnumPropertyItem proportional_falloff_items[] = {
 	{PROP_SMOOTH, "SMOOTH", ICON_SMOOTHCURVE, "Smooth", "Smooth falloff"},
 	{PROP_SPHERE, "SPHERE", ICON_SPHERECURVE, "Sphere", "Spherical falloff"},
 	{PROP_ROOT, "ROOT", ICON_ROOTCURVE, "Root", "Root falloff"},
+	{PROP_INVSQUARE, "INVERSE_SQUARE", ICON_ROOTCURVE, "Inverse Square", "Inverse Square falloff"},
 	{PROP_SHARP, "SHARP", ICON_SHARPCURVE, "Sharp", "Sharp falloff"},
 	{PROP_LIN, "LINEAR", ICON_LINCURVE, "Linear", "Linear falloff"},
 	{PROP_CONST, "CONSTANT", ICON_NOCURVE, "Constant", "Constant falloff"},
diff --git a/source/blender/modifiers/intern/MOD_warp.c b/source/blender/modifiers/intern/MOD_warp.c
index ed0d18fc484..3eb34e56700 100644
--- a/source/blender/modifiers/intern/MOD_warp.c
+++ b/source/blender/modifiers/intern/MOD_warp.c
@@ -265,6 +265,9 @@ static void warpModifier_do(WarpModifierData *wmd, Object *ob,
 				case eWarp_Falloff_Sphere:
 					fac = sqrtf(2 * fac - fac * fac);
 					break;
+				case eWarp_Falloff_InvSquare:
+					fac = fac * (2.0f - fac);
+					break;
 			}
 
 			fac *= weight;