F-Curve Modifiers: Groundwork for getting these working

- Completed cleaning up the drawing code so that F-Curves with modifiers now get drawn to reflect this.
- Added a temporary operator to add modifiers (hotkey Ctrl-Shift-M) 

2 files changed, 65 insertions, 3 deletions

diff --git a/source/blender/blenkernel/BKE_fcurve.h b/source/blender/blenkernel/BKE_fcurve.h
index a8b1ad49648..23c4579de14 100644
--- a/source/blender/blenkernel/BKE_fcurve.h
+++ b/source/blender/blenkernel/BKE_fcurve.h
@@ -44,6 +44,8 @@ typedef struct FModifierTypeInfo {
 	/* admin/ident */
 	short type;				/* FMODIFIER_TYPE_### */
 	short size;				/* size in bytes of the struct */
+	short acttype;			/* eFMI_Action_Types */
+	short requires;			/* eFMI_Requirement_Flags */
 	char name[32]; 			/* name of modifier in interface */
 	char structName[32];	/* name of struct for SDNA */
 	
@@ -60,13 +62,37 @@ typedef struct FModifierTypeInfo {
 	void (*evaluate_modifier)(struct FCurve *fcu, struct FModifier *fcm, float *cvalue, float evaltime);
 } FModifierTypeInfo;
 
+/* Values which describe the behaviour of a FModifier Type */
+enum {
+		/* modifier only modifies values outside of data range */
+	FMI_TYPE_EXTRAPOLATION = 0,
+		/* modifier leaves data-points alone, but adjusts the interpolation between and around them */
+	FMI_TYPE_INTERPOLATION,
+		/* modifier only modifies the values of points (but times stay the same) */
+	FMI_TYPE_REPLACE_VALUES,
+		/* modifier generates a curve regardless of what came before */
+	FMI_TYPE_GENERATE_CURVE,
+} eFMI_Action_Types;
+
+/* Flags for the requirements of a FModifier Type */
+enum {
+		/* modifier requires original data-points (kindof beats the purpose of a modifier stack?) */
+	FMI_REQUIRES_ORIGINAL_DATA		= (1<<0),
+		/* modifier doesn't require on any preceeding data (i.e. it will generate a curve). 
+		 * Use in conjunction with FMI_TYPE_GENRATE_CURVE 
+		 */
+	FMI_REQUIRES_NOTHING			= (1<<1),
+		/* refer to modifier instance */
+	FMI_REQUIRES_RUNTIME_CHECK		= (1<<2),
+} eFMI_Requirement_Flags;
+
 /* Function Prototypes for FModifierTypeInfo's */
 FModifierTypeInfo *fmodifier_get_typeinfo(struct FModifier *fcm);
 FModifierTypeInfo *get_fmodifier_typeinfo(int type);
 
 /* ---------------------- */
 
-// TODO... general API here..
+struct FModifier *fcurve_active_modifier(struct FCurve *fcu);
 struct FModifier *fcurve_add_modifier(struct FCurve *fcu, int type);
 void fcurve_copy_modifiers(ListBase *dst, ListBase *src);
 void fcurve_remove_modifier(struct FCurve *fcu, struct FModifier *fcm);
diff --git a/source/blender/blenkernel/intern/fcurve.c b/source/blender/blenkernel/intern/fcurve.c
index 6f3cad7995c..e73a2e158ad 100644
--- a/source/blender/blenkernel/intern/fcurve.c
+++ b/source/blender/blenkernel/intern/fcurve.c
@@ -1105,6 +1105,8 @@ static float fcurve_eval_samples (FCurve *fcu, FPoint *fpts, float evaltime)
 static FModifierTypeInfo FMI_MODNAME = {
 	FMODIFIER_TYPE_MODNAME, /* type */
 	sizeof(FMod_ModName), /* size */
+	FMI_TYPE_SOME_ACTION, /* action type */
+	FMI_REQUIRES_SOME_REQUIREMENT, /* requirements */
 	"Modifier Name", /* name */
 	"FMod_ModName", /* struct name */
 	fcm_modname_free, /* free data */
@@ -1155,6 +1157,7 @@ static void fcm_generator_evaluate (FCurve *fcu, FModifier *fcm, float *cvalue,
 	
 	/* behaviour depends on mode (NOTE: we don't need to do anything...) */
 	switch (data->mode) {
+		// TODO: implement factorised polynomial too
 		case FCM_GENERATOR_POLYNOMIAL: /* polynomial expression */
 		{
 			/* we overwrite cvalue with the sum of the polynomial */
@@ -1184,6 +1187,8 @@ static void fcm_generator_evaluate (FCurve *fcu, FModifier *fcm, float *cvalue,
 static FModifierTypeInfo FMI_GENERATOR = {
 	FMODIFIER_TYPE_GENERATOR, /* type */
 	sizeof(FMod_Generator), /* size */
+	FMI_TYPE_GENERATE_CURVE, /* action type */
+	FMI_REQUIRES_NOTHING, /* requirements */
 	"Generator", /* name */
 	"FMod_Generator", /* struct name */
 	fcm_generator_free, /* free data */
@@ -1266,6 +1271,8 @@ static void fcm_envelope_evaluate (FCurve *fcu, FModifier *fcm, float *cvalue, f
 static FModifierTypeInfo FMI_ENVELOPE = {
 	FMODIFIER_TYPE_ENVELOPE, /* type */
 	sizeof(FMod_Envelope), /* size */
+	FMI_TYPE_REPLACE_VALUES, /* action type */
+	0, /* requirements */
 	"Envelope", /* name */
 	"FMod_Envelope", /* struct name */
 	fcm_envelope_free, /* free data */
@@ -1399,6 +1406,8 @@ static void fcm_cycles_evaluate (FCurve *fcu, FModifier *fcm, float *cvalue, flo
 static FModifierTypeInfo FMI_CYCLES = {
 	FMODIFIER_TYPE_CYCLES, /* type */
 	sizeof(FMod_Cycles), /* size */
+	FMI_TYPE_EXTRAPOLATION, /* action type */
+	FMI_REQUIRES_ORIGINAL_DATA, /* requirements */
 	"Cycles", /* name */
 	"FMod_Cycles", /* struct name */
 	NULL, /* free data */
@@ -1413,6 +1422,8 @@ static FModifierTypeInfo FMI_CYCLES = {
 static FModifierTypeInfo FMI_NOISE = {
 	FMODIFIER_TYPE_NOISE, /* type */
 	sizeof(FMod_Noise), /* size */
+	FMI_TYPE_REPLACE_VALUES, /* action type */
+	0, /* requirements */
 	"Noise", /* name */
 	"FMod_Noise", /* struct name */
 	NULL, /* free data */
@@ -1428,6 +1439,8 @@ static FModifierTypeInfo FMI_NOISE = {
 static FModifierTypeInfo FMI_FILTER = {
 	FMODIFIER_TYPE_FILTER, /* type */
 	sizeof(FMod_Filter), /* size */
+	FMI_TYPE_REPLACE_VALUES, /* action type */
+	0, /* requirements */
 	"Filter", /* name */
 	"FMod_Filter", /* struct name */
 	NULL, /* free data */
@@ -1480,6 +1493,8 @@ static void fcm_python_evaluate (FCurve *fcu, FModifier *fcm, float *cvalue, flo
 static FModifierTypeInfo FMI_PYTHON = {
 	FMODIFIER_TYPE_PYTHON, /* type */
 	sizeof(FMod_Python), /* size */
+	FMI_TYPE_GENERATE_CURVE, /* action type */
+	FMI_REQUIRES_RUNTIME_CHECK, /* requirements */
 	"Python", /* name */
 	"FMod_Python", /* struct name */
 	fcm_python_free, /* free data */
@@ -1499,7 +1514,8 @@ static FModifierTypeInfo *fmodifiersTypeInfo[FMODIFIER_NUM_TYPES];
 static short FMI_INIT= 1; /* when non-zero, the list needs to be updated */
 
 /* This function only gets called when FMI_INIT is non-zero */
-static void fmods_init_typeinfo () {
+static void fmods_init_typeinfo () 
+{
 	fmodifiersTypeInfo[0]=  NULL; 					/* 'Null' F-Curve Modifier */
 	fmodifiersTypeInfo[1]=  &FMI_GENERATOR; 		/* Generator F-Curve Modifier */
 	fmodifiersTypeInfo[2]=  &FMI_ENVELOPE;			/* Envelope F-Curve Modifier */
@@ -1568,6 +1584,8 @@ FModifier *fcurve_add_modifier (FCurve *fcu, int type)
 	
 	/* add modifier itself */
 	fcm= MEM_callocN(sizeof(FModifier), "F-Curve Modifier");
+	fcm->type = type;
+	fcm->flag = FMODIFIER_FLAG_EXPANDED;
 	BLI_addtail(&fcu->modifiers, fcm);
 	
 	/* add modifier's data */
@@ -1674,12 +1692,30 @@ void fcurve_bake_modifiers (FCurve *fcu, int start, int end)
 	fcu->driver= driver;
 }
 
+/* Find the active F-Curve Modifier */
+FModifier *fcurve_active_modifier (FCurve *fcu)
+{
+	FModifier *fcm;
+	
+	/* sanity checks */
+	if ELEM(NULL, fcu, fcu->modifiers.first)
+		return NULL;
+	
+	/* loop over modifiers until 'active' one is found */
+	for (fcm= fcu->modifiers.first; fcm; fcm= fcm->next) {
+		if (fcm->flag & FMODIFIER_FLAG_ACTIVE)
+			return fcm;
+	}
+	
+	/* no modifier is active */
+	return NULL;
+}
+
 /* ***************************** F-Curve - Evaluation ********************************* */
 
 /* Evaluate and return the value of the given F-Curve at the specified frame ("evaltime") 
  * Note: this is also used for drivers
  */
-// TODO: set up the modifier system...
 float evaluate_fcurve (FCurve *fcu, float evaltime) 
 {
 	FModifier *fcm;