Multiline in dimension description / suffix / prefix #3005

Also added some offset for dimension text in viewport to make it more similar to svg

src/blenderbim/blenderbim/bim/module/drawing/decoration.py

@@ -377,17 +377,42 @@ class BaseDecorator:
         font_size_mm=2.5,
         line_no=0,
         box_alignment=None,
+        multiline=False,
+        multiline_to_bottom=True,
     ):
         """Draw text label
 
         Args:
           pos: bottom-center
+          multiline: \n characters will be interpreted as line breaks
 
         aligned and centered at segment middle
 
         NOTE: `blf.draw` seems to ignore the \n character, so we have to split the text ourselves
         and use the `line_no` argument of `draw_label`
+
         """
+
+        if multiline:
+            line_no = 0
+            lines = text.split("\\n")
+            lines = lines if multiline_to_bottom else lines[::-1]
+            for line in lines:
+                self.draw_label(
+                    context,
+                    line,
+                    pos,
+                    text_dir,
+                    gap=gap,
+                    center=center,
+                    vcenter=vcenter,
+                    font_size_mm=font_size_mm,
+                    line_no=line_no,
+                    box_alignment=box_alignment,
+                )
+                line_no += 1 if multiline_to_bottom else -1
+            return
+
         # 0 is the default font, but we're fancier than that
         font_id = self.font_id
 
@@ -492,7 +517,7 @@ class BaseDecorator:
             start_i = add_verts_sequence(add_offsets(v0, segment), start_i, **out_kwargs)
         self.draw_lines(context, obj, output_verts, output_edges)
 
-    def draw_text(self, context, obj, text_world_position=None):
+    def draw_text(self, context, obj, text_world_position=None, reverse_lines_order=False):
         """if `text_world_position` is not provided, the object's location will be used"""
         if not text_world_position:
             text_world_position = obj.location
@@ -522,6 +547,7 @@ class BaseDecorator:
             text_scale = obj.scale.x
 
         line_i = 0
+        font_size_mm = text_data["FontSize"] * text_scale
         for literal_data in literals_data:
             box_alignment = literal_data["BoxAlignment"]
 
@@ -534,11 +560,11 @@ class BaseDecorator:
                     gap=0,
                     center=False,
                     vcenter=False,
-                    font_size_mm=text_data["FontSize"] * text_scale,
+                    font_size_mm=font_size_mm,
                     line_no=line_i,
                     box_alignment=box_alignment,
                 )
-                line_i += 1
+                line_i += 1 if not reverse_lines_order else -1
 
 
 class DimensionDecorator(BaseDecorator):
@@ -624,6 +650,8 @@ class DimensionDecorator(BaseDecorator):
         show_description_only = dimension_data["show_description_only"]
         text_prefix = dimension_data["text_prefix"]
         text_suffix = dimension_data["text_suffix"]
+        viewportDrawingScale = self.get_viewport_drawing_scale(context)
+        text_offset_value = viewportDrawingScale * 3
 
         for i0, i1 in indices:
             v0 = Vector(vertices[i0])
@@ -633,6 +661,8 @@ class DimensionDecorator(BaseDecorator):
             text_dir = p1 - p0
             if text_dir.length < 1:
                 continue
+            perpendicular = Vector((-text_dir.y, text_dir.x)).normalized()
+            text_offset = perpendicular * text_offset_value
 
             if not show_description_only:
                 length = (v1 - v0).length
@@ -641,12 +671,35 @@ class DimensionDecorator(BaseDecorator):
                 text = self.format_value(context, length)
                 text = text_prefix + text + text_suffix
 
-                self.draw_label(context, text, p0 + text_dir * 0.5, text_dir, box_alignment="bottom-middle")
+                self.draw_label(
+                    context,
+                    text,
+                    p0 + text_dir * 0.5 + text_offset,
+                    text_dir,
+                    box_alignment="bottom-middle",
+                    multiline=True,
+                    multiline_to_bottom=False,
+                )
                 if description:
-                    self.draw_label(context, description, p0 + text_dir * 0.5, text_dir, box_alignment="top-middle")
+                    self.draw_label(
+                        context,
+                        description,
+                        p0 + text_dir * 0.5 - text_offset,
+                        text_dir,
+                        box_alignment="top-middle",
+                        multiline=True,
+                    )
 
             elif show_description_only and description:
-                self.draw_label(context, description, p0 + text_dir * 0.5, text_dir, box_alignment="bottom-middle")
+                self.draw_label(
+                    context,
+                    description,
+                    p0 + text_dir * 0.5 + text_offset,
+                    text_dir,
+                    box_alignment="bottom-middle",
+                    multiline=True,
+                    multiline_to_bottom=False,
+                )
 
 
 class AngleDecorator(BaseDecorator):

src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py

@@ -1149,28 +1149,86 @@ class SvgWriter:
 
         # if annotation can't fit offset text to the right of marker
         text_position = mid if sheet_dimension > 5 else (end + (3 * vector.normalized()))
-        rotation = math.degrees(vector.angle_signed(Vector((1, 0))))
+        angle = math.degrees(vector.angle_signed(Vector((1, 0))))
 
         line = self.svg.line(start=start, end=end, class_=" ".join(classes))
         self.svg.add(line)
 
-        def create_text_tag(text, text_position, box_alignment):
-            text_kwargs = {"transform": "rotate({} {} {})".format(rotation, text_position.x, text_position.y)}
+        if not show_description_only:
+            text = f"{text_prefix}{str(dimension)}{text_suffix}"
+            text_tag = self.create_text_tag(
+                text,
+                text_position + perpendicular,
+                angle,
+                "bottom-middle",
+                "DIMENSION",
+                text_format=text_format,
+                multiline=True,
+                multiline_to_bottom=False,
+            )
+            self.svg.add(text_tag)
+            if dimension_text:
+                text_tag = self.create_text_tag(
+                    dimension_text,
+                    text_position - perpendicular,
+                    angle,
+                    "top-middle",
+                    "DIMENSION",
+                    text_format=text_format,
+                    multiline=True,
+                    multiline_to_bottom=True,
+                )
+                self.svg.add(text_tag)
+
+        elif show_description_only and dimension_text:
+            text_tag = self.create_text_tag(
+                dimension_text,
+                text_position + perpendicular,
+                angle,
+                "bottom-middle",
+                "DIMENSION",
+                text_format=text_format,
+                multiline=True,
+                multiline_to_bottom=False,
+            )
+            self.svg.add(text_tag)
+
+    def create_text_tag(
+        self,
+        text,
+        text_position,
+        angle,
+        box_alignment,
+        class_str,
+        text_format=lambda x: x,
+        multiline=False,
+        multiline_to_bottom=False,
+    ):
+        if not multiline:
+            text_kwargs = {"transform": "rotate({} {} {})".format(angle, text_position.x, text_position.y)}
             return self.svg.text(
                 text_format(text),
                 insert=text_position,
-                class_="DIMENSION",
+                class_=class_str,
                 **(text_kwargs | SvgWriter.get_box_alignment_parameters(box_alignment)),
             )
 
-        if not show_description_only:
-            text = f"{text_prefix}{str(dimension)}{text_suffix}"
-            self.svg.add(create_text_tag(text, text_position + perpendicular, "bottom-middle"))
-            if dimension_text:
-                self.svg.add(create_text_tag(dimension_text, text_position - perpendicular, "top-middle"))
+        text_position_svg_str = ", ".join(map(str, text_position))
+        text_transform = f"translate({text_position_svg_str}) rotate({angle})"
+        text_kwargs = {
+            "transform": text_transform,
+            "style": "font-size: 0;",
+        }
 
-        elif show_description_only and dimension_text:
-            self.svg.add(create_text_tag(dimension_text, text_position + perpendicular, "bottom-middle"))
+        text_tag = self.svg.text("", **text_kwargs, **SvgWriter.get_box_alignment_parameters(box_alignment))
+        text_lines = text.replace("\\n", "\n").split("\n")
+        text_lines = text_lines if multiline_to_bottom else text_lines[::-1]
+
+        for line_number, text_line in enumerate(text_lines):
+            tspan = self.svg.tspan(text_format(text_line), class_=class_str, insert=(0, 0))
+            tspan.update({"dy": f"{line_number if multiline_to_bottom else -line_number}em"})
+            text_tag.add(tspan)
+        return text_tag
 
     def project_point_onto_camera(self, point):
         # TODO is this needlessly complex?