improve grid panel

src/util.h

@@ -180,6 +180,7 @@ struct gl_state
     GLint program;
     GLint fb;
     GLint active_tex;
+    GLfloat line_width;
     void save()
     {
         blend = glIsEnabled(GL_BLEND);
@@ -187,6 +188,7 @@ struct gl_state
         scissor_test = glIsEnabled(GL_SCISSOR_TEST);
         glGetIntegerv(GL_VIEWPORT, vp);
         glGetFloatv(GL_COLOR_CLEAR_VALUE, cc);
+        glGetFloatv(GL_LINE_WIDTH, &line_width);
         glGetIntegerv(GL_CURRENT_PROGRAM, &program);
         glGetIntegerv(GL_FRAMEBUFFER_BINDING, &fb);
         glGetIntegerv(GL_ACTIVE_TEXTURE, &active_tex);
@@ -215,5 +217,6 @@ struct gl_state
         }
         glActiveTexture(active_tex);
         glBindTexture(GL_TEXTURE_CUBE_MAP, cube);
+        glLineWidth(line_width);
     }
 };