Added to the Parameter Editor mode new stroke geometry modifier `Blueprint'

that produces a blueprint using circular, elliptic, and square contour strokes.
Related changes and bug fixes were made as follows:

* The randomness in radius and center has been transformed into optional
parameters of the pyBluePrintCirclesShader and pyBluePrintEllipsesShader.
Also a new optional parameter to control the randomness of backbone
stretching has been added to the pyBluePrintSquaresShader.

* A bug in the pyBluePrintSquaresShader that invisible stroke vertices at
corners of rectangular contour strokes were not properly drawn.  The problem
was due to the changes of the / operator between Python 2.x to 3.x.  Even
when the two operands of the division operator are integers, Python 3.x
gives a floating-point number when the quotient is not an integer.  The fix
was just to replace the / operator by the // operator for integer division.

* An unpleasant discontinuity in circular and elliptical contour strokes
was fixed.

* The length parameter of the Backbone Stretcher geometry modifier has been
renamed to `backbone_length' in line with the parameter of the same name in
the pyBluePrintSquaresShader.

5 files changed, 88 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/linestyle.c b/source/blender/blenkernel/intern/linestyle.c
index a8d8038e7f9..0c48590410e 100644
--- a/source/blender/blenkernel/intern/linestyle.c
+++ b/source/blender/blenkernel/intern/linestyle.c
@@ -63,7 +63,8 @@ static char *modifier_name[LS_MODIFIER_NUM] = {
 	"Tip Remover",
 	"Calligraphy",
 	"Polygonalization",
-	"Guiding Lines"};
+	"Guiding Lines",
+	"Blueprint"};
 
 static void default_linestyle_settings(FreestyleLineStyle *linestyle)
 {
@@ -398,6 +399,9 @@ int FRS_add_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, int type)
 	case LS_MODIFIER_GUIDING_LINES:
 		size = sizeof(LineStyleGeometryModifier_GuidingLines);
 		break;
+	case LS_MODIFIER_BLUEPRINT:
+		size = sizeof(LineStyleGeometryModifier_Blueprint);
+		break;
 	default:
 		return -1; /* unknown modifier type */
 	}
@@ -435,7 +439,7 @@ int FRS_add_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, int type)
 		((LineStyleGeometryModifier_PerlinNoise2D *)m)->angle = 45.0;
 		break;
 	case LS_MODIFIER_BACKBONE_STRETCHER:
-		((LineStyleGeometryModifier_BackboneStretcher *)m)->amount = 10.0;
+		((LineStyleGeometryModifier_BackboneStretcher *)m)->backbone_length = 10.0;
 		break;
 	case LS_MODIFIER_TIP_REMOVER:
 		((LineStyleGeometryModifier_TipRemover *)m)->tip_length = 10.0;
@@ -446,6 +450,14 @@ int FRS_add_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, int type)
 	case LS_MODIFIER_GUIDING_LINES:
 		((LineStyleGeometryModifier_GuidingLines *)m)->offset = 0.0;
 		break;
+	case LS_MODIFIER_BLUEPRINT:
+		((LineStyleGeometryModifier_Blueprint *)m)->flags = LS_MODIFIER_BLUEPRINT_CIRCLES;
+		((LineStyleGeometryModifier_Blueprint *)m)->rounds = 1;
+		((LineStyleGeometryModifier_Blueprint *)m)->backbone_length = 10.f;
+		((LineStyleGeometryModifier_Blueprint *)m)->random_radius = 3;
+		((LineStyleGeometryModifier_Blueprint *)m)->random_center = 5;
+		((LineStyleGeometryModifier_Blueprint *)m)->random_backbone = 5;
+		break;
 	}
 	add_to_modifier_list(&linestyle->geometry_modifiers, m);
 	return 0;
@@ -474,6 +486,8 @@ void FRS_remove_linestyle_geometry_modifier(FreestyleLineStyle *linestyle, LineS
 		break;
 	case LS_MODIFIER_GUIDING_LINES:
 		break;
+	case LS_MODIFIER_BLUEPRINT:
+		break;
 	}
 	BLI_freelinkN(&linestyle->geometry_modifiers, m);
 }
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index b37364e830b..3accc871548 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -2723,6 +2723,9 @@ static void write_linestyle_geometry_modifiers(WriteData *wd, ListBase *modifier
 		case LS_MODIFIER_GUIDING_LINES:
 			struct_name = "LineStyleGeometryModifier_GuidingLines";
 			break;
+		case LS_MODIFIER_BLUEPRINT:
+			struct_name = "LineStyleGeometryModifier_Blueprint";
+			break;
 		default:
 			struct_name = "LineStyleGeometryModifier"; // this should not happen
 		}
diff --git a/source/blender/makesdna/DNA_linestyle_types.h b/source/blender/makesdna/DNA_linestyle_types.h
index a34a4285e55..a73dd707caa 100644
--- a/source/blender/makesdna/DNA_linestyle_types.h
+++ b/source/blender/makesdna/DNA_linestyle_types.h
@@ -64,7 +64,8 @@ typedef struct LineStyleModifier {
 #define LS_MODIFIER_CALLIGRAPHY            13
 #define LS_MODIFIER_POLYGONIZATION         14
 #define LS_MODIFIER_GUIDING_LINES          15
-#define LS_MODIFIER_NUM                    16
+#define LS_MODIFIER_BLUEPRINT              16
+#define LS_MODIFIER_NUM                    17
 
 /* LineStyleModifier::flags */
 #define LS_MODIFIER_ENABLED     1
@@ -284,7 +285,7 @@ typedef struct LineStyleGeometryModifier_PerlinNoise2D {
 typedef struct LineStyleGeometryModifier_BackboneStretcher {
 	struct LineStyleModifier modifier;
 
-	float amount;
+	float backbone_length;
 	int pad;
 
 } LineStyleGeometryModifier_BackboneStretcher;
@@ -313,6 +314,23 @@ typedef struct LineStyleGeometryModifier_GuidingLines {
 
 } LineStyleGeometryModifier_GuidingLines;
 
+/* LineStyleGeometryModifier_BluePrintLines::shape */
+#define LS_MODIFIER_BLUEPRINT_CIRCLES   1
+#define LS_MODIFIER_BLUEPRINT_ELLIPSES  2
+#define LS_MODIFIER_BLUEPRINT_SQUARES   4
+
+typedef struct LineStyleGeometryModifier_Blueprint {
+	struct LineStyleModifier modifier;
+
+	int flags;
+	unsigned int rounds;
+	float backbone_length;
+	unsigned int random_radius;
+	unsigned int random_center;
+	unsigned int random_backbone;
+
+} LineStyleGeometryModifier_Blueprint;
+
 /* Calligraphic thickness modifier */
 
 typedef struct LineStyleThicknessModifier_Calligraphy {
diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 67d4b2deee1..1e0231fd4a6 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -299,6 +299,7 @@ extern StructRNA RNA_LineStyleColorModifier_Material;
 extern StructRNA RNA_LineStyleGeometryModifier;
 extern StructRNA RNA_LineStyleGeometryModifier_BackboneStretcher;
 extern StructRNA RNA_LineStyleGeometryModifier_BezierCurve;
+extern StructRNA RNA_LineStyleGeometryModifier_Blueprint;
 extern StructRNA RNA_LineStyleGeometryModifier_GuidingLines;
 extern StructRNA RNA_LineStyleGeometryModifier_PerlinNoise1D;
 extern StructRNA RNA_LineStyleGeometryModifier_PerlinNoise2D;
diff --git a/source/blender/makesrna/intern/rna_linestyle.c b/source/blender/makesrna/intern/rna_linestyle.c
index 6ae8bd2253e..58be8fc62c4 100644
--- a/source/blender/makesrna/intern/rna_linestyle.c
+++ b/source/blender/makesrna/intern/rna_linestyle.c
@@ -61,6 +61,7 @@ EnumPropertyItem linestyle_thickness_modifier_type_items[] ={
 EnumPropertyItem linestyle_geometry_modifier_type_items[] ={
 	{LS_MODIFIER_BACKBONE_STRETCHER, "BACKBONE_STRETCHER", ICON_MODIFIER, "Backbone Stretcher", ""},
 	{LS_MODIFIER_BEZIER_CURVE, "BEZIER_CURVE", ICON_MODIFIER, "Bezier Curve", ""},
+	{LS_MODIFIER_BLUEPRINT, "BLUEPRINT", ICON_MODIFIER, "Blueprint", ""},
 	{LS_MODIFIER_GUIDING_LINES, "GUIDING_LINES", ICON_MODIFIER, "Guiding Lines", ""},
 	{LS_MODIFIER_PERLIN_NOISE_1D, "PERLIN_NOISE_1D", ICON_MODIFIER, "Perlin Noise 1D", ""},
 	{LS_MODIFIER_PERLIN_NOISE_2D, "PERLIN_NOISE_2D", ICON_MODIFIER, "Perlin Noise 2D", ""},
@@ -154,6 +155,8 @@ static StructRNA *rna_LineStyle_geometry_modifier_refine(struct PointerRNA *ptr)
 			return &RNA_LineStyleGeometryModifier_Polygonalization;
 		case LS_MODIFIER_GUIDING_LINES:
 			return &RNA_LineStyleGeometryModifier_GuidingLines;
+		case LS_MODIFIER_BLUEPRINT:
+			return &RNA_LineStyleGeometryModifier_Blueprint;
 		default:
 			return &RNA_LineStyleGeometryModifier;
 	}
@@ -378,6 +381,12 @@ static void rna_def_linestyle_modifiers(BlenderRNA *brna)
 	StructRNA *srna;
 	PropertyRNA *prop;
 
+	static EnumPropertyItem blueprint_shape_items[] = {
+		{LS_MODIFIER_BLUEPRINT_CIRCLES, "CIRCLES", 0, "Circles", "Draw a blueprint using circular contour strokes"},
+		{LS_MODIFIER_BLUEPRINT_ELLIPSES, "ELLIPSES", 0, "Ellipses", "Draw a blueprint using elliptic contour strokes"},
+		{LS_MODIFIER_BLUEPRINT_SQUARES, "SQUARES", 0, "Squares", "Draw a blueprint using square contour strokes"},
+		{0, NULL, 0, NULL, NULL}};
+
 	srna= RNA_def_struct(brna, "LineStyleModifier", NULL);
 	RNA_def_struct_ui_text(srna, "Line Style Modifier", "Base type to define modifiers");
 
@@ -651,9 +660,9 @@ static void rna_def_linestyle_modifiers(BlenderRNA *brna)
 	RNA_def_struct_ui_text(srna, "Backbone Stretcher", "Stretch the beginning and the end of stroke backbone");
 	rna_def_geometry_modifier(srna);
 
-	prop= RNA_def_property(srna, "amount", PROP_FLOAT, PROP_NONE);
-	RNA_def_property_float_sdna(prop, NULL, "amount");
-	RNA_def_property_ui_text(prop, "Amount", "Amount of stretching");
+	prop= RNA_def_property(srna, "backbone_length", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "backbone_length");
+	RNA_def_property_ui_text(prop, "Backbone Length", "Amount of backbone stretching");
 	RNA_def_property_update(prop, NC_SCENE, NULL);
 
 	srna= RNA_def_struct(brna, "LineStyleGeometryModifier_TipRemover", "LineStyleGeometryModifier");
@@ -683,6 +692,42 @@ static void rna_def_linestyle_modifiers(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Offset", "Displacement that is applied to the main direction line along its normal");
 	RNA_def_property_update(prop, NC_SCENE, NULL);
 
+	srna= RNA_def_struct(brna, "LineStyleGeometryModifier_Blueprint", "LineStyleGeometryModifier");
+	RNA_def_struct_ui_text(srna, "Blueprint", "Produce a blueprint using circular, elliptic, and square contour strokes");
+	rna_def_geometry_modifier(srna);
+
+	prop= RNA_def_property(srna, "shape", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_bitflag_sdna(prop, NULL, "flags");
+	RNA_def_property_enum_items(prop, blueprint_shape_items);
+	RNA_def_property_ui_text(prop, "Shape", "Select the shape of blueprint contour strokes");
+	RNA_def_property_update(prop, NC_SCENE, NULL);
+
+	prop= RNA_def_property(srna, "rounds", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_int_sdna(prop, NULL, "rounds");
+	RNA_def_property_range(prop, 1, 1000);
+	RNA_def_property_ui_text(prop, "Rounds", "Number of rounds in contour strokes");
+	RNA_def_property_update(prop, NC_SCENE, NULL);
+
+	prop= RNA_def_property(srna, "backbone_length", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "backbone_length");
+	RNA_def_property_ui_text(prop, "Backbone Length", "Amount of backbone stretching");
+	RNA_def_property_update(prop, NC_SCENE, NULL);
+
+	prop= RNA_def_property(srna, "random_radius", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_int_sdna(prop, NULL, "random_radius");
+	RNA_def_property_ui_text(prop, "Random Radius", "Randomness of the radius");
+	RNA_def_property_update(prop, NC_SCENE, NULL);
+
+	prop= RNA_def_property(srna, "random_center", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_int_sdna(prop, NULL, "random_center");
+	RNA_def_property_ui_text(prop, "Random Center", "Randomness of the center");
+	RNA_def_property_update(prop, NC_SCENE, NULL);
+
+	prop= RNA_def_property(srna, "random_backbone", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_int_sdna(prop, NULL, "random_backbone");
+	RNA_def_property_ui_text(prop, "Random Backbone", "Randomness of the backbone stretching");
+	RNA_def_property_update(prop, NC_SCENE, NULL);
+
 }
 
 static void rna_def_linestyle(BlenderRNA *brna)