== Constraints System - Recode 2 ==

Once again, I've recoded the constraints system. This time, the goals were:
* To make it more future-proof by 'modernising' the coding style. The long functions filled with switch statements, have given way to function-pointers with smaller functions for specific purposes.
* To make it support constraints which use multiple targets more readily that it did. In the past, it was assumed that constraints could only have at most one target.

As a result, a lot of code has been shuffled around, and modified. Also, the subversion number has been bumped up.

Known issues:
* PyConstraints, which were the main motivation for supporting multiple-targets, are currently broken. There are some bimport() error that keeps causing problems. I've also temporarily removed the doDriver support, although it may return in another form soon. 
* Constraints BPy-API is currently has a few features which currently don't work yet
* Outliner currently only displays the names of the constraints instead of the fancy subtarget/target/constraint-name display it used to do. What gets displayed here needs further investigation, as the old way was certainly not that great (and is not compatible with the new system too) 

1 files changed, 112 insertions, 56 deletions

diff --git a/source/blender/makesdna/DNA_constraint_types.h b/source/blender/makesdna/DNA_constraint_types.h
index fcde95371ac..e06063a11a1 100644
--- a/source/blender/makesdna/DNA_constraint_types.h
+++ b/source/blender/makesdna/DNA_constraint_types.h
@@ -36,13 +36,11 @@
 
 #include "DNA_ID.h"
 #include "DNA_ipo_types.h"
+#include "DNA_listBase.h"
 #include "DNA_object_types.h"
 
 struct Action;
 struct Text;
-#ifndef __cplusplus
-struct PyObject;
-#endif
 
 /* channels reside in Object or Action (ListBase) constraintChannels */
 typedef struct bConstraintChannel {
@@ -55,29 +53,67 @@ typedef struct bConstraintChannel {
 /* A Constraint */
 typedef struct bConstraint {
 	struct bConstraint *next, *prev;
+	
 	void		*data;		/*	Constraint data	(a valid constraint type) */
 	short		type;		/*	Constraint type	*/
 	short		flag;		/*	Flag - General Settings	*/
 	
 	char 		ownspace;	/* 	Space that owner should be evaluated in 	*/
-	char		tarspace;	/* 	Space that target should be evaluated in 	*/
+	char		tarspace;	/* 	Space that target should be evaluated in (only used if 1 target) */
 	
-	char		name[30];	/*	Constraint name	*/
+	char		name[30];	/*	Constraint name */
 	
 	float		enforce;	/* 	Amount of influence exherted by constraint (0.0-1.0) */
 } bConstraint;
 
 
-/* Python Script Constraint */
-typedef struct bPythonConstraint {
-	Object *tar;			/* object to use as target (if required) */
-	char subtarget[32]; 	/* bone to use as subtarget (if required) */
+/* Multiple-target constraints ---------------------  */
+
+/* This struct defines a constraint target.
+ * It is used during constraint solving regardless of how many targets the
+ * constraint has.
+ */
+typedef struct bConstraintTarget {
+	struct bConstraintTarget *next, *prev;
+
+	Object *tar;			/* object to use as target */
+	char subtarget[32];		/* subtarget - pchan or vgroup name */
+	
+	float matrix[4][4];		/* matrix used during constraint solving - should be cleared before each use */
 	
+	short space;			/* space that target should be evaluated in (overrides bConstraint->tarspace) */
+	short flag;				/* runtime settings (for editor, etc.) */
+	short type;				/* type of target (B_CONSTRAINT_OB_TYPE) */
+	short pad;
+} bConstraintTarget;
+
+/* bConstraintTarget -> flag */
+typedef enum B_CONSTRAINT_TARGET_FLAG {
+	CONSTRAINT_TAR_TEMP = (1<<0),		/* temporary target-struct that needs to be freed after use */
+} B_CONSTRAINT_TARGET_FLAG;
+
+/* bConstraintTarget/bConstraintOb -> type */
+typedef enum B_CONSTRAINT_OB_TYPE {
+	CONSTRAINT_OBTYPE_OBJECT = 1,	/*	string is ""				*/
+	CONSTRAINT_OBTYPE_BONE,			/*	string is bone-name		*/
+	CONSTRAINT_OBTYPE_VERT,			/*	string is vertex-group name 	*/
+	CONSTRAINT_OBTYPE_CV			/* 	string is vertex-group name - is not available until curves get vgroups */
+} B_CONSTRAINT_OB_TYPE;
+
+
+
+/* Python Script Constraint */
+typedef struct bPythonConstraint {	
 	struct Text *text;		/* text-buffer (containing script) to execute */
 	IDProperty *prop;		/* 'id-properties' used to store custom properties for constraint */
 	
 	int flag;				/* general settings/state indicators accessed by bitmapping */
-	int pad;
+	int tarnum;				/* number of targets - usually only 1-3 are needed */
+	
+	ListBase targets;		/* a list of targets that this constraint has (bConstraintTarget-s) */
+	
+	Object *tar;			/* target from previous implementation (version-patch sets this to NULL on file-load) */
+	char subtarget[32];		/* subtarger from previous implentation (version-patch sets this to "" on file-load) */
 } bPythonConstraint;
 
 /* Single-target subobject constraints ---------------------  */
@@ -125,10 +161,10 @@ typedef struct bLocateLikeConstraint {
 typedef struct bMinMaxConstraint {
 	Object		*tar;
 	int			minmaxflag;
-	float			offset;
-	int				flag;
-	short			sticky, stuck, pad1, pad2; /* for backward compatability */
-	float			cache[3];
+	float		offset;
+	int			flag;
+	short		sticky, stuck, pad1, pad2; /* for backward compatability */
+	float		cache[3];
 	char		subtarget[32];
 } bMinMaxConstraint;
 
@@ -143,13 +179,13 @@ typedef struct bSizeLikeConstraint {
 /* Action Constraint */
 typedef struct bActionConstraint {
 	Object		*tar;
-	short		type;
+	short		type;	/* what transform 'channel' drives the result */
 	short		local;	/* was used in versions prior to the Constraints recode */
-	int		start;
-	int		end;
+	int			start;
+	int			end;
 	float		min;
 	float		max;
-	int             pad;
+	int         pad;
 	struct bAction	*act;
 	char		subtarget[32];
 } bActionConstraint;
@@ -261,53 +297,73 @@ typedef struct bSizeLimitConstraint {
 	short		pad1;
 } bSizeLimitConstraint;
 
-/* bConstraint.type */
-#define CONSTRAINT_TYPE_NULL		0
-#define CONSTRAINT_TYPE_CHILDOF		1		/* Unimplemented non longer :) - during constraints recode, Aligorith */
-#define CONSTRAINT_TYPE_TRACKTO		2	
-#define CONSTRAINT_TYPE_KINEMATIC	3	
-#define CONSTRAINT_TYPE_FOLLOWPATH	4
-#define CONSTRAINT_TYPE_ROTLIMIT	5		/* Unimplemented no longer :) - Aligorith */
-#define CONSTRAINT_TYPE_LOCLIMIT	6		/* Unimplemented no longer :) - Aligorith */
-#define CONSTRAINT_TYPE_SIZELIMIT	7		/* Unimplemented no longer :) - Aligorith */
-#define CONSTRAINT_TYPE_ROTLIKE		8	
-#define CONSTRAINT_TYPE_LOCLIKE		9	
-#define CONSTRAINT_TYPE_SIZELIKE	10
-#define CONSTRAINT_TYPE_PYTHON		11		/* Unimplemented no longer :) - Aligorith. Scripts */
-#define CONSTRAINT_TYPE_ACTION		12
-#define CONSTRAINT_TYPE_LOCKTRACK	13		/* New Tracking constraint that locks an axis in place - theeth */
-#define CONSTRAINT_TYPE_DISTANCELIMIT 14 	/* was never properly coded - removed! */
-#define CONSTRAINT_TYPE_STRETCHTO	15  	/* claiming this to be mine :) is in tuhopuu bjornmose */ 
-#define CONSTRAINT_TYPE_MINMAX      16  	/* floor constraint */
-#define CONSTRAINT_TYPE_RIGIDBODYJOINT 17 	/* rigidbody constraint */
-#define CONSTRAINT_TYPE_CLAMPTO		18  	/* clampto constraint */	
-#define CONSTRAINT_TYPE_TRANSFORM	19 		/* transformation constraint */	
+/* ------------------------------------------ */
+
+/* bConstraint->type 
+ * 	- Do not ever change the order of these, or else files could get
+ * 	  broken as their correct value cannot be resolved
+ */
+typedef enum B_CONSTAINT_TYPES {
+	CONSTRAINT_TYPE_NULL = 0,			/* Invalid/legacy constraint */
+	CONSTRAINT_TYPE_CHILDOF,			/* Unimplemented non longer :) - during constraints recode, Aligorith */
+	CONSTRAINT_TYPE_TRACKTO,
+	CONSTRAINT_TYPE_KINEMATIC,
+	CONSTRAINT_TYPE_FOLLOWPATH,
+	CONSTRAINT_TYPE_ROTLIMIT,			/* Unimplemented no longer :) - Aligorith */
+	CONSTRAINT_TYPE_LOCLIMIT,			/* Unimplemented no longer :) - Aligorith */
+	CONSTRAINT_TYPE_SIZELIMIT,			/* Unimplemented no longer :) - Aligorith */
+	CONSTRAINT_TYPE_ROTLIKE,	
+	CONSTRAINT_TYPE_LOCLIKE,	
+	CONSTRAINT_TYPE_SIZELIKE,
+	CONSTRAINT_TYPE_PYTHON,				/* Unimplemented no longer :) - Aligorith. Scripts */
+	CONSTRAINT_TYPE_ACTION,
+	CONSTRAINT_TYPE_LOCKTRACK,			/* New Tracking constraint that locks an axis in place - theeth */
+	CONSTRAINT_TYPE_DISTANCELIMIT,		/* was never properly coded - removed! */
+	CONSTRAINT_TYPE_STRETCHTO, 			/* claiming this to be mine :) is in tuhopuu bjornmose */ 
+	CONSTRAINT_TYPE_MINMAX,  			/* floor constraint */
+	CONSTRAINT_TYPE_RIGIDBODYJOINT,		/* rigidbody constraint */
+	CONSTRAINT_TYPE_CLAMPTO, 			/* clampto constraint */	
+	CONSTRAINT_TYPE_TRANSFORM,			/* transformation (loc/rot/size -> loc/rot/size) constraint */	
+	
+	/* NOTE: everytime a new constraint is added, update this */
+	NUM_CONSTRAINT_TYPES= CONSTRAINT_TYPE_TRANSFORM
+} B_CONSTRAINT_TYPES; 
 
 /* bConstraint->flag */
+/* flags 0x2 (1<<1) and 0x8 (1<<3) were used in past */
+/* flag 0x20 (1<<5) was used to indicate that a constraint was evaluated using a 'local' hack for posebones only  */
+typedef enum B_CONSTRAINT_FLAG {
 		/* expand for UI */
-#define CONSTRAINT_EXPAND		0x01
+	CONSTRAINT_EXPAND =		(1<<0), 
 		/* pre-check for illegal object name or bone name */
-#define CONSTRAINT_DISABLE		0x04
-		/* flags 0x2 and 0x8 were used in past, skip this */
-		/* to indicate which Ipo should be shown, maybe for 3d access later too */
-#define CONSTRAINT_ACTIVE		0x10
-		/* flag 0x20 was used to indicate that a constraint was evaluated using a 'local' hack for posebones only  */
+	CONSTRAINT_DISABLE = 	(1<<2), 
+		/* to indicate which Ipo should be shown, maybe for 3d access later too */	
+	CONSTRAINT_ACTIVE = 	(1<<4), 
 		/* to indicate that the owner's space should only be changed into ownspace, but not out of it */
-#define CONSTRAINT_SPACEONCE	0x40
+	CONSTRAINT_SPACEONCE = 	(1<<6)  
+} B_CONSTRAINT_FLAG;
 
 /* bConstraint->ownspace/tarspace */
-	/* default for all - worldspace */
-#define CONSTRAINT_SPACE_WORLD			0
-	/* for objects (relative to parent/without parent influence), for bones (along normals of bone, without parent/restposi) */
-#define CONSTRAINT_SPACE_LOCAL			1
-	/* for posechannels - pose space  */
-#define CONSTRAINT_SPACE_POSE			2
-	/* for posechannels - local with parent  */
-#define CONSTRAINT_SPACE_PARLOCAL		3
+typedef enum B_CONSTRAINT_SPACETYPES {
+		/* default for all - worldspace */
+	CONSTRAINT_SPACE_WORLD = 0,
+		/* for objects (relative to parent/without parent influence), 
+		 * for bones (along normals of bone, without parent/restpositions) 
+		 */
+	CONSTRAINT_SPACE_LOCAL,
+		/* for posechannels - pose space  */
+	CONSTRAINT_SPACE_POSE,
+		/* for posechannels - local with parent  */
+	CONSTRAINT_SPACE_PARLOCAL,
+} B_CONSTRAINT_SPACETYPES;
 
 /* bConstraintChannel.flag */
-#define CONSTRAINT_CHANNEL_SELECT		0x01
-#define CONSTRAINT_CHANNEL_PROTECTED 	0x02
+typedef enum B_CONSTRAINTCHANNEL_FLAG {
+	CONSTRAINT_CHANNEL_SELECT =		(1<<0),
+	CONSTRAINT_CHANNEL_PROTECTED =	(1<<1)
+} B_CONSTRAINTCHANNEL_FLAG;
+
+/* -------------------------------------- */
 
 /**
  * The flags for ROTLIKE, LOCLIKE and SIZELIKE should be kept identical