F-Modifiers (in Nla branch):

For fun, added 'sinc' (i.e. y = sin(pi*x)/(pi*x)) as a type of builtin function usable through the generator modifier. This makes a nice 'jolt' which tapers off.

4 files changed, 22 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/fcurve.c b/source/blender/blenkernel/intern/fcurve.c
index 6a3870f8f31..5820761234c 100644
--- a/source/blender/blenkernel/intern/fcurve.c
+++ b/source/blender/blenkernel/intern/fcurve.c
@@ -1410,6 +1410,18 @@ static void fcm_generator_verify (FModifier *fcm)
 	}
 }
 
+/* Unary 'normalised sine' function
+ * 	y = sin(PI + x) / (PI * x),
+ * except for x = 0 when y = 1.
+ */
+static double sinc (double x)
+{
+    if (fabs(x) < 0.0001)
+        return 1.0;
+    else
+        return sin(M_PI * x) / (M_PI * x);
+}
+
 static void fcm_generator_evaluate (FCurve *fcu, FModifier *fcm, float *cvalue, float evaltime)
 {
 	FMod_Generator *data= (FMod_Generator *)fcm->data;
@@ -1490,6 +1502,9 @@ static void fcm_generator_evaluate (FCurve *fcu, FModifier *fcm, float *cvalue,
 				case FCM_GENERATOR_FN_COS: /* cosine wave */
 					fn= cos;
 					break;
+				case FCM_GENERATOR_FN_SINC: /* normalised sine wave */
+					fn= sinc;
+					break;
 					
 				/* validation required */
 				case FCM_GENERATOR_FN_TAN: /* tangent wave */
@@ -1527,7 +1542,7 @@ static void fcm_generator_evaluate (FCurve *fcu, FModifier *fcm, float *cvalue,
 					}
 				}
 					break;
-					
+				
 				default:
 					printf("Invalid Function-Generator for F-Modifier - %d \n", data->func_type);
 			}
diff --git a/source/blender/editors/space_graph/graph_buttons.c b/source/blender/editors/space_graph/graph_buttons.c
index a4babaad74c..5b00205b5d0 100644
--- a/source/blender/editors/space_graph/graph_buttons.c
+++ b/source/blender/editors/space_graph/graph_buttons.c
@@ -405,7 +405,7 @@ static void draw_modifier__generator(uiBlock *block, FCurve *fcu, FModifier *fcm
 {
 	FMod_Generator *data= (FMod_Generator *)fcm->data;
 	char gen_mode[]="Generator Type%t|Expanded Polynomial%x0|Factorised Polynomial%x1|Built-In Function%x2|Expression%x3";
-	char fn_type[]="Built-In Function%t|Sin%x0|Cos%x1|Tan%x2|Square Root%x3|Natural Log%x4";
+	char fn_type[]="Built-In Function%t|Sin%x0|Cos%x1|Tan%x2|Square Root%x3|Natural Log%x4|Normalised Sin%x5";
 	int cy= *yco - 30;
 	uiBut *but;
 	
@@ -555,6 +555,9 @@ static void draw_modifier__generator(uiBlock *block, FCurve *fcu, FModifier *fcm
 					case FCM_GENERATOR_FN_SQRT: /* square root */
 						sprintf(func_name, "sqrt(");
 						break;
+					case FCM_GENERATOR_FN_SINC: /* normalised sine wave */
+						sprintf(func_name, "sinc(");
+						break;
 					default: /* unknown */
 						sprintf(func_name, "<fn?>(");
 						break;
diff --git a/source/blender/makesdna/DNA_anim_types.h b/source/blender/makesdna/DNA_anim_types.h
index c19318629f6..a784adaf35f 100644
--- a/source/blender/makesdna/DNA_anim_types.h
+++ b/source/blender/makesdna/DNA_anim_types.h
@@ -108,6 +108,7 @@ enum {
 	FCM_GENERATOR_FN_TAN,
 	FCM_GENERATOR_FN_SQRT,
 	FCM_GENERATOR_FN_LN,
+	FCM_GENERATOR_FN_SINC,
 } eFMod_Generator_Functions;
 
 
diff --git a/source/blender/makesrna/intern/rna_fcurve.c b/source/blender/makesrna/intern/rna_fcurve.c
index ea26118f267..69103536310 100644
--- a/source/blender/makesrna/intern/rna_fcurve.c
+++ b/source/blender/makesrna/intern/rna_fcurve.c
@@ -284,6 +284,7 @@ static void rna_def_fmodifier_generator_function(BlenderRNA *brna)
 		{2, "TAN", "Tangent", ""},
 		{3, "SQRT", "Square Root", ""},
 		{4, "LN", "Natural Logarithm", ""},
+		{5, "SINC", "Normalised Sine", "sin(x) / x"},
 		{0, NULL, NULL, NULL}};