Allow render cancel on exception

components/renderers/cpp/include/ftl/render/CUDARender.hpp

@@ -33,6 +33,8 @@ class CUDARender : public ftl::render::FSRenderer {
 
 	void blend(ftl::codecs::Channel) override;
 
+	void cancel() override;
+
 	/**
 	 * Returns all inter-frameset collisions in camera coordinates.
 	 */

components/renderers/cpp/include/ftl/render/renderer.hpp

@@ -47,6 +47,8 @@ class Renderer : public ftl::Configurable {
 
 	virtual void blend(ftl::codecs::Channel)=0;
 
+	virtual void cancel()=0;
+
 	protected:
 	Stage stage_;
 };

components/renderers/cpp/src/CUDARender.cpp

@@ -498,6 +498,13 @@ void CUDARender::_renderPass2(Channels<0> chans, const Eigen::Matrix4d &t) {
 	}
 }
 
+void CUDARender::cancel() {
+	out_ = nullptr;
+	scene_ = nullptr;
+	stage_ = Stage::Finished;
+	cudaSafeCall(cudaStreamSynchronize(stream_));
+}
+
 void CUDARender::begin(ftl::rgbd::Frame &out, ftl::codecs::Channel chan) {
 	if (stage_ != Stage::Finished) {
 		throw FTL_Error("Already rendering");

components/streams/src/renderers/openvr_render.cpp

@@ -448,6 +448,9 @@ bool OpenVRRender::retrieve(ftl::data::Frame &frame_out) {
 			renderer2_->end();
 		} catch (const ftl::exception &e) {
 			LOG(ERROR) << "Render exception: " << e.what();
+			renderer_->cancel();
+			renderer2_->cancel();
+			frame_out.message(ftl::data::Message::Error_RENDER, e.what());
 		}
 
 		if (!post_pipe_) {

components/streams/src/renderers/screen_render.cpp

@@ -206,6 +206,8 @@ bool ScreenRender::retrieve(ftl::data::Frame &frame_out) {
 			if (!data_only) renderer_->end();
 		} catch (const ftl::exception &e) {
 			LOG(ERROR) << "Render exception: " << e.what();
+			renderer_->cancel();
+			frame_out.message(ftl::data::Message::Error_RENDER, e.what());
 		}
 
 		if (!data_only) {

components/structures/include/ftl/data/messages.hpp

@@ -13,6 +13,7 @@ enum class Message : int {
 	Error_FRAME_GRAB,
 	Error_BAD_FORMAT,
 	Error_OPENVR,
+	Error_RENDER,
 	Warning_UNKNOWN = 1024,
 	Warning_FRAME_DROP,
 	Warning_PIPELINE_DROP,