Route framebuffer texture copies through GL backend

src/node_canvas.cpp

@@ -16,6 +16,7 @@
 #include "paint_renderer/compositor.h"
 #include "settings.h"
 #include "renderer_gl/opengl_capabilities.h"
+#include "util.h"
 
 namespace {
 
@@ -523,8 +524,13 @@ void NodeCanvas::draw()
                     {
                         set_active_texture_unit(2);
                         m_blender_bg.bind();
-                        glCopyTexSubImage2D(pp::renderer::gl::texture_2d_target(), 0, 0, 0, 0, 0,
-                            m_blender_bg.size().x, m_blender_bg.size().y);
+                        copy_framebuffer_to_texture_2d(
+                            0,
+                            0,
+                            0,
+                            0,
+                            m_blender_bg.size().x,
+                            m_blender_bg.size().y);
                     }
 
                     m_face_plane.draw_fill();