better newline logic when fixing curvature

__init__.py

@@ -244,6 +244,7 @@ class ABC3D_text_properties(bpy.types.PropertyGroup):
     compensate_curvature: bpy.props.BoolProperty(
             update=update_callback,
             name="Compensate Curvature",
+            description="Fixes curvature spacing issues for simple curves, don't use on curve with tiny loops.",
             default=True,
     )
     ignore_orientation: bpy.props.BoolProperty(

butils.py

@@ -245,6 +245,7 @@ def calc_point_on_bezier_spline(bezier_spline_obj,
 def calc_point_on_bezier_curve(bezier_curve_obj,
                                distance,
                                output_tangent = False,
+                               output_spline_index = False,
                                resolution_factor = 1.0):
     curve = bezier_curve_obj.data
 
@@ -254,6 +255,21 @@ def calc_point_on_bezier_curve(bezier_curve_obj,
         resolution = int(spline.resolution_u * resolution_factor)
         length = spline.calc_length(resolution=resolution)
         if total_length + length > distance or i == len(curve.splines) - 1:
+            if output_spline_index and output_tangent:
+                # return value from c_p_o_b_s is a tuple
+                # so we need to append tuple + tuple
+                return calc_point_on_bezier_spline(spline,
+                                                   (distance - total_length),
+                                                   output_tangent,
+                                                   resolution_factor) + (i,)
+            if output_spline_index and not output_tangent:
+                # return value from c_p_o_b_s is a location vector
+                # so we need to append with a comma
+                return calc_point_on_bezier_spline(spline,
+                                                   (distance - total_length),
+                                                   output_tangent,
+                                                   resolution_factor), i
+            else:
                 return calc_point_on_bezier_spline(spline,
                                                    (distance - total_length),
                                                    output_tangent,
@@ -677,18 +693,21 @@ def set_text_on_curve(text_properties, recursive=True):
     advance = text_properties.offset
     glyph_advance = 0
     is_command = False
+    previous_spline_index = -1
     for i, c in enumerate(text_properties.text):
         if c == '\\':
             is_command = True
             continue
+        is_newline = False
         if is_command:
             if c == 'n':
+                is_newline = True
                 next_line_advance = get_next_line_advance(mom, advance, glyph_advance)
                 if advance == next_line_advance:
                     # self.report({'INFO'}, f"would like to add new line for {text_properties.text} please")
                     print(f"would like to add new line for {text_properties.text} please")
                     # TODO: add a new line
-                advance = next_line_advance
+                advance = next_line_advance + text_properties.offset
                 continue
             is_command = False
         glyph_id = c
@@ -721,7 +740,9 @@ def set_text_on_curve(text_properties, recursive=True):
             ob.constraints["Follow Path"].forward_axis = "FORWARD_X"
             ob.constraints["Follow Path"].up_axis = "UP_Y"
         elif distribution_type == 'CALCULATE':
-            location, tangent = calc_point_on_bezier_curve(mom, advance, True)
+            location, tangent, spline_index = calc_point_on_bezier_curve(mom, advance, True, True)
+            if spline_index != previous_spline_index:
+                is_newline = True
             ob.location = mom.matrix_world @ (location + text_properties.translation)
             if not text_properties.ignore_orientation:
                 mask = [0]
@@ -754,20 +775,28 @@ def set_text_on_curve(text_properties, recursive=True):
         # otherwise letters will be closer together the curvier the bezier is
         # this could be done more efficiently, but whatever
         curve_compensation = 0
-        if distribution_type == 'CALCULATE':
+        if distribution_type == 'CALCULATE' and not is_newline:
             if text_properties.compensate_curvature and glyph_advance > 0:
-                previous_location = calc_point_on_bezier_curve(mom, advance, False)
+                previous_location, psi = calc_point_on_bezier_curve(mom, advance, False, True)
-                new_location = calc_point_on_bezier_curve(mom, advance + glyph_advance, False)
+                new_location, si = calc_point_on_bezier_curve(mom, advance + glyph_advance, False, True)
-                while (previous_location - new_location).length > glyph_advance:
+                if psi == si:
+                    while (previous_location - new_location).length > glyph_advance and psi == si:
                         curve_compensation = curve_compensation - glyph_advance * 0.01
-                    new_location = calc_point_on_bezier_curve(mom, advance + glyph_advance + curve_compensation, False)
+                        new_location, si = calc_point_on_bezier_curve(mom,
-                while (previous_location - new_location).length < glyph_advance:
+                                                                      advance + glyph_advance + curve_compensation,
+                                                                      output_tangent=False,
+                                                                      output_spline_index=True)
+                    while (previous_location - new_location).length < glyph_advance and psi == si:
                         curve_compensation = curve_compensation + glyph_advance * 0.01
-                    new_location = calc_point_on_bezier_curve(mom, advance + glyph_advance + curve_compensation, False)
+                        new_location, si = calc_point_on_bezier_curve(mom,
+                                                                      advance + glyph_advance + curve_compensation,
+                                                                      output_tangent=False,
+                                                                      output_spline_index=True)
 
         ob.scale = (scalor, scalor, scalor)
 
         advance = advance + glyph_advance + curve_compensation
+        previous_spline_index = spline_index
 
         if regenerate:
             mom.users_collection[0].objects.link(ob)