Route retained readbacks through GL backend

src/node_panel_grid.cpp

@@ -231,19 +231,7 @@ void NodePanelGrid::init_controls()
         m_texture.create_mipmaps();
 #else
         // get the texture data and resize it
-        Image img;
-        img.create(m_texture.size().x, m_texture.size().y);
-        App::I->render_task([&]
-        {
-            m_texture.bind();
-            glGetTexImage(
-                pp::renderer::gl::texture_2d_target(),
-                0,
-                pp::renderer::gl::rgba_pixel_format(),
-                pp::renderer::gl::unsigned_byte_component_type(),
-                img.m_data.get());
-            m_texture.unbind();
-        });
+        Image img = m_texture.get_image();
         Image resized = img.resize(texres, texres);
         m_texture.create(resized);
         m_texture.create_mipmaps();