See #2894. Implement SVG mirroring options (typically used for RCPs or useful when converting to other things like DXF).

src/serializers/SvgSerializer.cpp

@@ -773,7 +773,14 @@ void SvgSerializer::write(const geometry_data& data) {
 	// SVG has a coordinate system with the origin in the *upper*-left corner
 	// therefore we mirror the shape along the XZ-plane.	
 	gp_Trsf trsf_mirror;
-	trsf_mirror.SetMirror(gp_Ax2(gp::Origin(), gp::DY()));
+	if (!mirror_y_) {
+		trsf_mirror.SetMirror(gp_Ax2(gp::Origin(), gp::DY()));
+	}
+	if (mirror_x_) {
+		gp_Trsf mirror_x;
+		mirror_x.SetMirror(gp_Ax2(gp::Origin(), gp::DX()));
+		trsf_mirror.PreMultiply(mirror_x);
+	}
 	BRepBuilderAPI_Transform make_transform_mirror(compound_unmirrored, trsf_mirror, true);
 	make_transform_mirror.Build();
 	// (When determinant < 0, copy is implied and the input is not mutated.)
@@ -1679,6 +1686,13 @@ std::array<std::array<double, 3>, 3> SvgSerializer::resize() {
 			cy = ymin * sc;
 		}
 
+		if (mirror_y_) {
+			cy = - size_->second - cy;
+		}
+		if (mirror_x_) {
+			cx = - size_->first - cx;
+		}
+
 		m = {{ {{sc,0,-cx}},{{0,sc,-cy}},{{0,0,1}} }};
 
 		float_item_list::const_iterator it;
@@ -1716,7 +1730,14 @@ void SvgSerializer::draw_hlr(const gp_Pln& pln, const drawing_key& drawing_name)
 		TopoDS_Shape hlr_compound;
 		if (drawing_name.first == nullptr) {
 			gp_Trsf trsf_mirror;
-			trsf_mirror.SetMirror(gp_Ax2(gp::Origin(), gp::DY()));
+			if (!mirror_y_) {
+				trsf_mirror.SetMirror(gp_Ax2(gp::Origin(), gp::DY()));
+			}
+			if (mirror_x_) {
+				gp_Trsf mirror_x;
+				mirror_x.SetMirror(gp_Ax2(gp::Origin(), gp::DX()));
+				trsf_mirror.PreMultiply(mirror_x);
+			}
 			BRepBuilderAPI_Transform make_transform_mirror(hlr_compound_unmirrored, trsf_mirror, true);
 			make_transform_mirror.Build();
 			hlr_compound = make_transform_mirror.Shape();

src/serializers/SvgSerializer.h

@@ -524,6 +524,8 @@ protected:
 	bool emit_building_storeys_;
 	bool no_css_;
 	bool unify_inputs_;
+	bool mirror_y_;
+	bool mirror_x_;
 
 	int profile_threshold_;
 
@@ -575,6 +577,8 @@ public:
 		, polygonal_(false)
 		, emit_building_storeys_(true)
 		, no_css_(false)
+		, mirror_y_(false)
+		, mirror_x_(false)
 		, unify_inputs_(false)
 		, profile_threshold_(-1)
 		, file(0)
@@ -716,6 +720,22 @@ public:
 		return profile_threshold_;
 	}
 
+	void setMirrorY(bool b) {
+		mirror_y_ = b;
+	}
+
+	bool getMirrorY() const {
+		return mirror_y_;
+	}
+
+	void setMirrorX(bool b) {
+		mirror_x_ = b;
+	}
+
+	bool getMirrorX() const {
+		return mirror_x_;
+	}
+
 protected:
 	std::string writeMetadata(const drawing_meta& m);
 };