render task queue the color pick action

src/canvas.cpp

@@ -72,6 +72,8 @@ void Canvas::pick_update(int plane)
     if (m_pick_ready[plane])
         return;
     
+    App::I->render_task([this, plane]
+    {
         // save viewport and clear color states
         GLint vp[4];
         GLfloat cc[4];
@@ -105,7 +107,7 @@ void Canvas::pick_update(int plane)
         m_sampler.unbind();
 
         if (!m_pick_data[plane])
-        m_pick_data[plane] = std::make_unique<glm::u8vec4[]>(m_width*m_height);
+            m_pick_data[plane] = std::make_unique<glm::u8vec4[]>(m_width * m_height);
         glReadPixels(0, 0, m_width, m_height, GL_RGBA, GL_UNSIGNED_BYTE, m_pick_data[plane].get());
         m_tmp[i].unbindFramebuffer();
 
@@ -114,7 +116,7 @@ void Canvas::pick_update(int plane)
         glViewport(vp[0], vp[1], vp[2], vp[3]);
         glClearColor(cc[0], cc[1], cc[2], cc[3]);
         glActiveTexture(GL_TEXTURE0);
-
+    });
     
     m_pick_ready[plane] = true;
 }