Update camera settings for commandline rendering from the file context
unless the --camera option is given in which case the camera is locked.

Signed-off-by: Herbert Poetzl <herbert@13thfloor.at>
---

diff -u b/src/Camera.cc b/src/Camera.cc
--- b/src/Camera.cc
+++ b/src/Camera.cc
@@ -15,6 +15,7 @@
 
 	pixel_width = RenderSettings::inst()->img_width;
 	pixel_height = RenderSettings::inst()->img_height;
+	locked = false;
 }
 
 void Camera::setup(std::vector<double> params)
@@ -38,6 +39,7 @@
 	} else {
 		assert("Gimbal cam needs 7 numbers, Vector camera needs 6");
 	}
+	locked = true;
 }
 /*!
 	Moves camera so that the given bbox is fully visible.
@@ -60,6 +62,7 @@
 		PRINTDB("modified obj trans x y z %f %f %f",object_trans.x() % object_trans.y() % object_trans.z());
 		PRINTDB("modified obj rot   x y z %f %f %f",object_rot.x() % object_rot.y() % object_rot.z());
 	}
+	locked = true;
 }
 
 void Camera::zoom(int zoom, bool relative)
@@ -90,6 +93,9 @@
  */
 void Camera::updateView(const std::shared_ptr<FileContext> ctx)
 {
+	if (locked)
+		return;
+
 	double x, y, z;
 	const auto vpr = ctx->lookup_variable("$vpr");
 	if (vpr->getVec3(x, y, z, 0.0)){
diff -u b/src/Camera.h b/src/Camera.h
--- b/src/Camera.h
+++ b/src/Camera.h
@@ -61,6 +61,10 @@
 	unsigned int pixel_width;
 	unsigned int pixel_height;
 
+	// true if camera settings are fixed 
+	// (--camera option in commandline mode)
+	bool locked;
+
 protected:
 	// Perspective settings
 	double viewer_distance;
only in patch2:
unchanged:
--- a/src/openscad.cc
+++ b/src/openscad.cc
@@ -379,7 +379,9 @@ int cmdline(const char *deps_output_file, const std::string &filename, const std
 	top_ctx->setDocumentPath(fparent.string());
 
 	AbstractNode::resetIndexCounter();
-	absolute_root_node = root_module->instantiate(top_ctx.ctx, &root_inst, nullptr);
+	ContextHandle<FileContext> filectx{Context::create<FileContext>(top_ctx.ctx)};
+	absolute_root_node = root_module->instantiateWithFileContext(filectx.ctx, &root_inst, nullptr);
+	camera.updateView(filectx.ctx);
 
 	// Do we have an explicit root node (! modifier)?
 	const Location *nextLocation = nullptr;