Stroke geometry modifiers

Added a set of stroke geometry modifiers to the Geometry tab of line styles
in the Parameter Editor mode.  Now the following stroke geometry modifiers are
available, each with a set of animateable parameters:
- Sampling: changes the resolution of stroke backbone polylines.
- Bezier Curve: replace stroke backbone with a Bezier approximation of the
  stroke backbone.
- Sinus Displacement: add sinus displacement to stroke backbone.
- Spatial Noise: add spatial noise to stroke backbone.
- Perlin Noise 1D: add one-dimensional Perlin noise to stroke backbone.
- Perlin Noise 2D: add two-dimensional Perlin noise to stroke backbone.
- Backbone Stretcher: stretch the beginning and the end of strokes.
- Tip Remover: remove a piece of stroke at the beginning and the end of strokes.

To branch users: When you have a .blend file with Freestyle options specified,
you may want to add a Sampling modifier with the 'sampling' value set to 5.
This value specifies a resolution of polylines for line drawing in Freestyle.
If no sampling modifier is specified, your line drawing will result in coarse
polylines.  Before geometry modifiers were introduced, this initial sampling
was automatically done.  Now the initial sampling is a tunable parameter that
can be omitted, allowing better control on polyline resolution.

2 files changed, 179 insertions, 48 deletions

diff --git a/source/blender/blenkernel/BKE_linestyle.h b/source/blender/blenkernel/BKE_linestyle.h
index ebbfe7c5559..ccf8e1c6b30 100644
--- a/source/blender/blenkernel/BKE_linestyle.h
+++ b/source/blender/blenkernel/BKE_linestyle.h
@@ -37,6 +37,7 @@
 #define LS_MODIFIER_TYPE_COLOR      1
 #define LS_MODIFIER_TYPE_ALPHA      2
 #define LS_MODIFIER_TYPE_THICKNESS  3
+#define LS_MODIFIER_TYPE_GEOMETRY   4
 
 struct Main;
 struct Object;
@@ -47,14 +48,17 @@ void FRS_free_linestyle(FreestyleLineStyle *linestyle);
 int FRS_add_linestyle_color_modifier(FreestyleLineStyle *linestyle, int type);
 int FRS_add_linestyle_alpha_modifier(FreestyleLineStyle *linestyle, int type);
 int FRS_add_linestyle_thickness_modifier(FreestyleLineStyle *linestyle, int type);
+int FRS_add_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, int type);
 
 void FRS_remove_linestyle_color_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier);
 void FRS_remove_linestyle_alpha_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier);
 void FRS_remove_linestyle_thickness_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier);
+void FRS_remove_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier);
 
 void FRS_move_linestyle_color_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier, int direction);
 void FRS_move_linestyle_alpha_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier, int direction);
 void FRS_move_linestyle_thickness_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier, int direction);
+void FRS_move_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier, int direction);
 
 void FRS_list_modifier_color_ramps(FreestyleLineStyle *linestyle, ListBase *listbase);
 char *FRS_path_from_ID_to_color_ramp(FreestyleLineStyle *linestyle, ColorBand *color_ramp);
diff --git a/source/blender/blenkernel/intern/linestyle.c b/source/blender/blenkernel/intern/linestyle.c
index 76371af3b8f..90b35e1f220 100644
--- a/source/blender/blenkernel/intern/linestyle.c
+++ b/source/blender/blenkernel/intern/linestyle.c
@@ -52,11 +52,19 @@ static char *modifier_name[LS_MODIFIER_NUM] = {
 	"Along Stroke",
 	"Distance from Camera",
 	"Distance from Object",
-	"Material"};
+	"Material",
+	"Sampling",
+	"Bezier Curve",
+	"Sinus Displacement",
+	"Spatial Noise",
+	"Perlin Noise 1D",
+	"Perlin Noise 2D",
+	"Backbone Stretcher",
+	"Tip Remover"};
 
 static void default_linestyle_settings(FreestyleLineStyle *linestyle)
 {
-	linestyle->panel = LS_PANEL_COLOR;
+	linestyle->panel = LS_PANEL_STROKES;
 	linestyle->r = linestyle->g = linestyle->b = 0.0;
 	linestyle->alpha = 1.0;
 	linestyle->thickness = 1.0;
@@ -64,6 +72,9 @@ static void default_linestyle_settings(FreestyleLineStyle *linestyle)
 	linestyle->color_modifiers.first = linestyle->color_modifiers.last = NULL;
 	linestyle->alpha_modifiers.first = linestyle->alpha_modifiers.last = NULL;
 	linestyle->thickness_modifiers.first = linestyle->thickness_modifiers.last = NULL;
+	linestyle->geometry_modifiers.first = linestyle->geometry_modifiers.last = NULL;
+
+	FRS_add_linestyle_geometry_modifier(linestyle, LS_MODIFIER_SAMPLING);
 
 	linestyle->caps = LS_CAPS_BUTT;
 }
@@ -93,6 +104,8 @@ void FRS_free_linestyle(FreestyleLineStyle *linestyle)
 		FRS_remove_linestyle_alpha_modifier(linestyle, m);
 	while ((m = (LineStyleModifier *)linestyle->thickness_modifiers.first))
 		FRS_remove_linestyle_thickness_modifier(linestyle, m);
+	while ((m = (LineStyleModifier *)linestyle->geometry_modifiers.first))
+		FRS_remove_linestyle_geometry_modifier(linestyle, m);
 }
 
 static LineStyleModifier *new_modifier(int type, size_t size)
@@ -117,40 +130,45 @@ static void add_to_modifier_list(ListBase *lb, LineStyleModifier *m)
 
 int FRS_add_linestyle_color_modifier(FreestyleLineStyle *linestyle, int type)
 {
-	static size_t modifier_size[LS_MODIFIER_NUM] = {
-		0,
-		sizeof(LineStyleColorModifier_AlongStroke),
-		sizeof(LineStyleColorModifier_DistanceFromCamera),
-		sizeof(LineStyleColorModifier_DistanceFromObject),
-		sizeof(LineStyleColorModifier_Material)
-	};
+	size_t size;
 	LineStyleModifier *m;
 
-	if (type <= 0 || type >= LS_MODIFIER_NUM || modifier_size[type] == 0)
-		return -1;
-	m = new_modifier(type, modifier_size[type]);
+	switch (type) {
+	case LS_MODIFIER_ALONG_STROKE:
+		size = sizeof(LineStyleColorModifier_AlongStroke);
+		break;
+	case LS_MODIFIER_DISTANCE_FROM_CAMERA:
+		size = sizeof(LineStyleColorModifier_DistanceFromCamera);
+		break;
+	case LS_MODIFIER_DISTANCE_FROM_OBJECT:
+		size = sizeof(LineStyleColorModifier_DistanceFromObject);
+		break;
+	case LS_MODIFIER_MATERIAL:
+		size = sizeof(LineStyleColorModifier_Material);
+		break;
+	default:
+		return -1; /* unknown modifier type */
+	}
+	m = new_modifier(type, size);
 	if (!m)
 		return -1;
+	m->blend = MA_RAMP_BLEND;
 	switch (type) {
 	case LS_MODIFIER_ALONG_STROKE:
 		((LineStyleColorModifier_AlongStroke *)m)->color_ramp = add_colorband(1);
-		((LineStyleColorModifier_AlongStroke *)m)->blend = MA_RAMP_BLEND;
 		break;
 	case LS_MODIFIER_DISTANCE_FROM_CAMERA:
 		((LineStyleColorModifier_DistanceFromCamera *)m)->color_ramp = add_colorband(1);
-		((LineStyleColorModifier_DistanceFromCamera *)m)->blend = MA_RAMP_BLEND;
 		((LineStyleColorModifier_DistanceFromCamera *)m)->range_min = 0.0f;
 		((LineStyleColorModifier_DistanceFromCamera *)m)->range_max = 10000.0f;
 		break;
 	case LS_MODIFIER_DISTANCE_FROM_OBJECT:
 		((LineStyleColorModifier_DistanceFromObject *)m)->target = NULL;
 		((LineStyleColorModifier_DistanceFromObject *)m)->color_ramp = add_colorband(1);
-		((LineStyleColorModifier_DistanceFromObject *)m)->blend = MA_RAMP_BLEND;
 		((LineStyleColorModifier_DistanceFromObject *)m)->range_min = 0.0f;
 		((LineStyleColorModifier_DistanceFromObject *)m)->range_max = 10000.0f;
 		break;
 	case LS_MODIFIER_MATERIAL:
-		((LineStyleColorModifier_Material *)m)->blend = MA_RAMP_BLEND;
 		((LineStyleColorModifier_Material *)m)->color_ramp = add_colorband(1);
 		((LineStyleColorModifier_Material *)m)->mat_attr = LS_MODIFIER_MATERIAL_DIFF;
 		break;
@@ -183,45 +201,48 @@ void FRS_remove_linestyle_color_modifier(FreestyleLineStyle *linestyle, LineStyl
 
 int FRS_add_linestyle_alpha_modifier(FreestyleLineStyle *linestyle, int type)
 {
-	static size_t modifier_size[LS_MODIFIER_NUM] = {
-		0,
-		sizeof(LineStyleAlphaModifier_AlongStroke),
-		sizeof(LineStyleAlphaModifier_DistanceFromCamera),
-		sizeof(LineStyleAlphaModifier_DistanceFromObject),
-		sizeof(LineStyleAlphaModifier_Material)
-	};
+	size_t size;
 	LineStyleModifier *m;
 
-	if (type <= 0 || type >= LS_MODIFIER_NUM || modifier_size[type] == 0)
-		return -1;
-	m = new_modifier(type, modifier_size[type]);
+	switch (type) {
+	case LS_MODIFIER_ALONG_STROKE:
+		size = sizeof(LineStyleAlphaModifier_AlongStroke);
+		break;
+	case LS_MODIFIER_DISTANCE_FROM_CAMERA:
+		size = sizeof(LineStyleAlphaModifier_DistanceFromCamera);
+		break;
+	case LS_MODIFIER_DISTANCE_FROM_OBJECT:
+		size = sizeof(LineStyleAlphaModifier_DistanceFromObject);
+		break;
+	case LS_MODIFIER_MATERIAL:
+		size = sizeof(LineStyleAlphaModifier_Material);
+		break;
+	default:
+		return -1; /* unknown modifier type */
+	}
+	m = new_modifier(type, size);
 	if (!m)
 		return -1;
+	m->blend = LS_VALUE_BLEND;
 	switch (type) {
 	case LS_MODIFIER_ALONG_STROKE:
 		((LineStyleAlphaModifier_AlongStroke *)m)->curve = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
-		((LineStyleAlphaModifier_AlongStroke *)m)->blend = LS_VALUE_BLEND;
 		break;
 	case LS_MODIFIER_DISTANCE_FROM_CAMERA:
 		((LineStyleAlphaModifier_DistanceFromCamera *)m)->curve = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
-		((LineStyleAlphaModifier_DistanceFromCamera *)m)->blend = LS_VALUE_BLEND;
 		((LineStyleAlphaModifier_DistanceFromCamera *)m)->range_min = 0.0f;
 		((LineStyleAlphaModifier_DistanceFromCamera *)m)->range_max = 10000.0f;
 		break;
 	case LS_MODIFIER_DISTANCE_FROM_OBJECT:
 		((LineStyleAlphaModifier_DistanceFromObject *)m)->target = NULL;
 		((LineStyleAlphaModifier_DistanceFromObject *)m)->curve = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
-		((LineStyleAlphaModifier_DistanceFromObject *)m)->blend = LS_VALUE_BLEND;
 		((LineStyleAlphaModifier_DistanceFromObject *)m)->range_min = 0.0f;
 		((LineStyleAlphaModifier_DistanceFromObject *)m)->range_max = 10000.0f;
 		break;
 	case LS_MODIFIER_MATERIAL:
 		((LineStyleAlphaModifier_Material *)m)->curve = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
-		((LineStyleAlphaModifier_Material *)m)->blend = LS_VALUE_BLEND;
 		((LineStyleAlphaModifier_Material *)m)->mat_attr = LS_MODIFIER_MATERIAL_DIFF;
 		break;
-	default:
-		return -1; /* unknown modifier type */
 	}
 	add_to_modifier_list(&linestyle->alpha_modifiers, m);
 
@@ -249,30 +270,37 @@ void FRS_remove_linestyle_alpha_modifier(FreestyleLineStyle *linestyle, LineStyl
 
 int FRS_add_linestyle_thickness_modifier(FreestyleLineStyle *linestyle, int type)
 {
-	static size_t modifier_size[LS_MODIFIER_NUM] = {
-		0,
-		sizeof(LineStyleThicknessModifier_AlongStroke),
-		sizeof(LineStyleThicknessModifier_DistanceFromCamera),
-		sizeof(LineStyleThicknessModifier_DistanceFromObject),
-		sizeof(LineStyleThicknessModifier_Material)
-	};
+	size_t size;
 	LineStyleModifier *m;
 
-	if (type <= 0 || type >= LS_MODIFIER_NUM || modifier_size[type] == 0)
-		return -1;
-	m = new_modifier(type, modifier_size[type]);
+	switch (type) {
+	case LS_MODIFIER_ALONG_STROKE:
+		size = sizeof(LineStyleThicknessModifier_AlongStroke);
+		break;
+	case LS_MODIFIER_DISTANCE_FROM_CAMERA:
+		size = sizeof(LineStyleThicknessModifier_DistanceFromCamera);
+		break;
+	case LS_MODIFIER_DISTANCE_FROM_OBJECT:
+		size = sizeof(LineStyleThicknessModifier_DistanceFromObject);
+		break;
+	case LS_MODIFIER_MATERIAL:
+		size = sizeof(LineStyleThicknessModifier_Material);
+		break;
+	default:
+		return -1; /* unknown modifier type */
+	}
+	m = new_modifier(type, size);
 	if (!m)
 		return -1;
+	m->blend = LS_VALUE_BLEND;
 	switch (type) {
 	case LS_MODIFIER_ALONG_STROKE:
 		((LineStyleThicknessModifier_AlongStroke *)m)->curve = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
-		((LineStyleThicknessModifier_AlongStroke *)m)->blend = LS_VALUE_BLEND;
 		((LineStyleThicknessModifier_AlongStroke *)m)->value_min = 0.0f;
 		((LineStyleThicknessModifier_AlongStroke *)m)->value_max = 1.0f;
 		break;
 	case LS_MODIFIER_DISTANCE_FROM_CAMERA:
 		((LineStyleThicknessModifier_DistanceFromCamera *)m)->curve = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
-		((LineStyleThicknessModifier_DistanceFromCamera *)m)->blend = LS_VALUE_BLEND;
 		((LineStyleThicknessModifier_DistanceFromCamera *)m)->range_min = 0.0f;
 		((LineStyleThicknessModifier_DistanceFromCamera *)m)->range_max = 1000.0f;
 		((LineStyleThicknessModifier_DistanceFromCamera *)m)->value_min = 0.0f;
@@ -281,7 +309,6 @@ int FRS_add_linestyle_thickness_modifier(FreestyleLineStyle *linestyle, int type
 	case LS_MODIFIER_DISTANCE_FROM_OBJECT:
 		((LineStyleThicknessModifier_DistanceFromObject *)m)->target = NULL;
 		((LineStyleThicknessModifier_DistanceFromObject *)m)->curve = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
-		((LineStyleThicknessModifier_DistanceFromObject *)m)->blend = LS_VALUE_BLEND;
 		((LineStyleThicknessModifier_DistanceFromObject *)m)->range_min = 0.0f;
 		((LineStyleThicknessModifier_DistanceFromObject *)m)->range_max = 1000.0f;
 		((LineStyleThicknessModifier_DistanceFromObject *)m)->value_min = 0.0f;
@@ -289,13 +316,10 @@ int FRS_add_linestyle_thickness_modifier(FreestyleLineStyle *linestyle, int type
 		break;
 	case LS_MODIFIER_MATERIAL:
 		((LineStyleThicknessModifier_Material *)m)->curve = curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
-		((LineStyleThicknessModifier_Material *)m)->blend = LS_VALUE_BLEND;
 		((LineStyleThicknessModifier_Material *)m)->mat_attr = LS_MODIFIER_MATERIAL_DIFF;
 		((LineStyleThicknessModifier_Material *)m)->value_min = 0.0f;
 		((LineStyleThicknessModifier_Material *)m)->value_max = 1.0f;
 		break;
-	default:
-		return -1; /* unknown modifier type */
 	}
 	add_to_modifier_list(&linestyle->thickness_modifiers, m);
 
@@ -321,6 +345,104 @@ void FRS_remove_linestyle_thickness_modifier(FreestyleLineStyle *linestyle, Line
 	BLI_freelinkN(&linestyle->thickness_modifiers, m);
 }
 
+int FRS_add_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, int type)
+{
+	size_t size;
+	LineStyleModifier *m;
+
+	switch (type) {
+	case LS_MODIFIER_SAMPLING:
+		size = sizeof(LineStyleGeometryModifier_Sampling);
+		break;
+	case LS_MODIFIER_BEZIER_CURVE:
+		size = sizeof(LineStyleGeometryModifier_BezierCurve);
+		break;
+	case LS_MODIFIER_SINUS_DISPLACEMENT:
+		size = sizeof(LineStyleGeometryModifier_SinusDisplacement);
+		break;
+	case LS_MODIFIER_SPATIAL_NOISE:
+		size = sizeof(LineStyleGeometryModifier_SpatialNoise);
+		break;
+	case LS_MODIFIER_PERLIN_NOISE_1D:
+		size = sizeof(LineStyleGeometryModifier_PerlinNoise1D);
+		break;
+	case LS_MODIFIER_PERLIN_NOISE_2D:
+		size = sizeof(LineStyleGeometryModifier_PerlinNoise2D);
+		break;
+	case LS_MODIFIER_BACKBONE_STRETCHER:
+		size = sizeof(LineStyleGeometryModifier_BackboneStretcher);
+		break;
+	case LS_MODIFIER_TIP_REMOVER:
+		size = sizeof(LineStyleGeometryModifier_TipRemover);
+		break;
+	default:
+		return -1; /* unknown modifier type */
+	}
+	m = new_modifier(type, size);
+	if (!m)
+		return -1;
+	switch (type) {
+	case LS_MODIFIER_SAMPLING:
+		((LineStyleGeometryModifier_Sampling *)m)->sampling = 10.0;
+		break;
+	case LS_MODIFIER_BEZIER_CURVE:
+		((LineStyleGeometryModifier_BezierCurve *)m)->error = 10.0;
+		break;
+	case LS_MODIFIER_SINUS_DISPLACEMENT:
+		((LineStyleGeometryModifier_SinusDisplacement *)m)->wavelength = 20.0;
+		((LineStyleGeometryModifier_SinusDisplacement *)m)->amplitude = 5.0;
+		((LineStyleGeometryModifier_SinusDisplacement *)m)->phase = 0.0;
+		break;
+	case LS_MODIFIER_SPATIAL_NOISE:
+		((LineStyleGeometryModifier_SpatialNoise *)m)->amplitude = 5.0;
+		((LineStyleGeometryModifier_SpatialNoise *)m)->scale = 20.0;
+		((LineStyleGeometryModifier_SpatialNoise *)m)->octaves = 4;
+		((LineStyleGeometryModifier_SpatialNoise *)m)->flags = LS_MODIFIER_SPATIAL_NOISE_SMOOTH | LS_MODIFIER_SPATIAL_NOISE_PURERANDOM;
+		break;
+	case LS_MODIFIER_PERLIN_NOISE_1D:
+		((LineStyleGeometryModifier_PerlinNoise1D *)m)->frequency = 10.0;
+		((LineStyleGeometryModifier_PerlinNoise1D *)m)->amplitude = 10.0;
+		((LineStyleGeometryModifier_PerlinNoise1D *)m)->octaves = 4;
+		break;
+	case LS_MODIFIER_PERLIN_NOISE_2D:
+		((LineStyleGeometryModifier_PerlinNoise2D *)m)->frequency = 10.0;
+		((LineStyleGeometryModifier_PerlinNoise2D *)m)->amplitude = 10.0;
+		((LineStyleGeometryModifier_PerlinNoise2D *)m)->octaves = 4;
+		break;
+	case LS_MODIFIER_BACKBONE_STRETCHER:
+		((LineStyleGeometryModifier_BackboneStretcher *)m)->amount = 10.0;
+		break;
+	case LS_MODIFIER_TIP_REMOVER:
+		((LineStyleGeometryModifier_TipRemover *)m)->tip_length = 10.0;
+		break;
+	}
+	add_to_modifier_list(&linestyle->geometry_modifiers, m);
+	return 0;
+}
+
+void FRS_remove_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *m)
+{
+	switch (m->type) {
+	case LS_MODIFIER_SAMPLING:
+		break;
+	case LS_MODIFIER_BEZIER_CURVE:
+		break;
+	case LS_MODIFIER_SINUS_DISPLACEMENT:
+		break;
+	case LS_MODIFIER_SPATIAL_NOISE:
+		break;
+	case LS_MODIFIER_PERLIN_NOISE_1D:
+		break;
+	case LS_MODIFIER_PERLIN_NOISE_2D:
+		break;
+	case LS_MODIFIER_BACKBONE_STRETCHER:
+		break;
+	case LS_MODIFIER_TIP_REMOVER:
+		break;
+	}
+	BLI_freelinkN(&linestyle->geometry_modifiers, m);
+}
+
 static void move_modifier(ListBase *lb, LineStyleModifier *modifier, int direction)
 {
 	BLI_remlink(lb, modifier);
@@ -345,6 +467,11 @@ void FRS_move_linestyle_thickness_modifier(FreestyleLineStyle *linestyle, LineSt
 	move_modifier(&linestyle->thickness_modifiers, modifier, direction);
 }
 
+void FRS_move_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, LineStyleModifier *modifier, int direction)
+{
+	move_modifier(&linestyle->geometry_modifiers, modifier, direction);
+}
+
 void FRS_list_modifier_color_ramps(FreestyleLineStyle *linestyle, ListBase *listbase)
 {
 	LineStyleModifier *m;