From 8686462eed566af6c4f8fe91345026e60395ca67 Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Tue, 29 Mar 2022 20:44:20 +1100
Subject: [PATCH] #1153. Section markers are now supported in SVG.

---
 .../blenderbim/bim/data/templates/symbols.svg |  7 +++++
 .../blenderbim/bim/module/drawing/operator.py |  2 ++
 .../bim/module/drawing/svgwriter.py           | 26 +++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/src/blenderbim/blenderbim/bim/data/templates/symbols.svg b/src/blenderbim/blenderbim/bim/data/templates/symbols.svg
index 1dc3c36950..ea0e4b3630 100644
--- a/src/blenderbim/blenderbim/bim/data/templates/symbols.svg
+++ b/src/blenderbim/blenderbim/bim/data/templates/symbols.svg
@@ -14,4 +14,11 @@
         <circle r="5" fill="white" stroke="black" style="stroke-width: 0.25;" />
         <line x1="-5" y1="0" x2="5" y2="0" style="stroke: black; stroke-width: 0.25;" />
     </g>
+    <g id="section-arrow">
+        <path style="fill: black;" d="M -7.07106 0 0 -7.07106 7.07106 0" />
+    </g>
+    <g id="section-tag">
+        <circle r="5" fill="white" stroke="black" style="stroke-width: 0.25;" />
+        <line x1="-5" y1="0" x2="5" y2="0" style="stroke: black; stroke-width: 0.25;" />
+    </g>
 </svg>
diff --git a/src/blenderbim/blenderbim/bim/module/drawing/operator.py b/src/blenderbim/blenderbim/bim/module/drawing/operator.py
index a519ccd9a2..c7d083fa13 100644
--- a/src/blenderbim/blenderbim/bim/module/drawing/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/drawing/operator.py
@@ -459,6 +459,8 @@ class CreateDrawing(bpy.types.Operator):
                 svg_writer.annotations.setdefault("dimension_objs", []).append(obj)
             elif element.ObjectType == "ELEVATION":
                 svg_writer.annotations.setdefault("elevation_objs", []).append(obj)
+            elif element.ObjectType == "SECTION":
+                svg_writer.annotations.setdefault("section_objs", []).append(obj)
             elif element.ObjectType == "BREAKLINE":
                 svg_writer.annotations["break_obj"] = obj
             elif element.ObjectType == "HIDDEN_LINE":
diff --git a/src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py b/src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py
index 4e81798518..b13656735c 100644
--- a/src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py
+++ b/src/blenderbim/blenderbim/bim/module/drawing/svgwriter.py
@@ -290,6 +290,9 @@ class SvgWriter:
         for obj in self.annotations.get("elevation_objs", []):
             self.draw_elevation_annotation(obj)
 
+        for obj in self.annotations.get("section_objs", []):
+            self.draw_section_annotation(obj)
+
         for text_obj in self.annotations.get("text_objs", []):
             self.draw_text_annotation(text_obj, text_obj.location)
 
@@ -430,6 +433,29 @@ class SvgWriter:
                 position = Vector((0, 0, 0))
             self.draw_text_annotation(obj, position)
 
+    def draw_section_annotation(self, obj):
+        x_offset = self.raw_width / 2
+        y_offset = self.raw_height / 2
+
+        self.draw_line_annotation((obj, obj.data), ["solid"])
+
+        v1 = self.project_point_onto_camera(obj.matrix_world @ Vector((0, 0, 0)))
+        v2 = self.project_point_onto_camera(obj.matrix_world @ Vector((0, 0, -1)))
+        angle = -math.degrees((v2 - v1).xy.angle_signed(Vector((0, 1))))
+
+        for vert in obj.data.vertices:
+            point = obj.matrix_world @ vert.co
+            symbol_position = self.project_point_onto_camera(point)
+            symbol_position = Vector(((x_offset + symbol_position.x), (y_offset - symbol_position.y)))
+            transform = "rotate({}, {}, {})".format(
+                angle,
+                (symbol_position * self.scale)[0],
+                (symbol_position * self.scale)[1],
+            )
+
+            self.svg.add(self.svg.use("#section-arrow", insert=tuple(symbol_position * self.scale), transform=transform))
+            self.svg.add(self.svg.use("#section-tag", insert=tuple(symbol_position * self.scale)))
+
     def draw_elevation_annotation(self, obj):
         x_offset = self.raw_width / 2
         y_offset = self.raw_height / 2