Extract stroke draw pad face helper

src/canvas.h

@@ -238,6 +238,15 @@ public:
     bool project_open_thread(std::string file_path);
     void inject_xmp(std::string jpg_path);
     Image thumbnail_generate(int w, int h);
+
+private:
+    void stroke_draw_pad_pass(
+        const std::array<pp::panopainter::LegacyCanvasStrokePadFace, 6>& pad_faces,
+        bool copy_stroke_destination,
+        const std::array<pp::panopainter::LegacyCanvasStrokeTextureBinding, 1>& pad_destination_texture_binding,
+        const pp::panopainter::LegacyCanvasStrokeTextureInputDispatch& pad_destination_texture_dispatch,
+        const pp::renderer::Extent2D& stroke_extent,
+        const glm::vec4& pad_color);
     Image thumbnail_read(std::string file_path);
     void draw_objects(std::function<void(const glm::mat4& camera, const glm::mat4& proj, int i)>, int frame, bool save_history);
     void draw_objects(std::function<void(const glm::mat4& camera, const glm::mat4& proj, int i)>, Layer& layer, int frame, bool save_history);