[gtk/wip/chergert/glproto] use split_draw() when processing glyphs

[Christian Hergert <chergert src gnome org>]

commit 3a34e9e53fe7a174e4bf14c1fb9342ce5400b21c
Author: Christian Hergert <chergert redhat com>
Date:   Mon Feb 1 10:36:33 2021 -0800

    use split_draw() when processing glyphs
    
    only if we change atlas texture, but use the split draw instead of the
    full state tracking end_draw/begin_draw

 gsk/next/gskglrenderjob.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)
---
diff --git a/gsk/next/gskglrenderjob.c b/gsk/next/gskglrenderjob.c
index 2e5ba9196a..c5225e0155 100644
--- a/gsk/next/gskglrenderjob.c
+++ b/gsk/next/gskglrenderjob.c
@@ -2657,18 +2657,13 @@ gsk_gl_render_job_visit_text_node (GskGLRenderJob *job,
 
       if G_UNLIKELY (last_texture != texture_id)
         {
-          gsk_gl_program_end_draw (program);
+          if G_LIKELY (last_texture != 0)
+            gsk_gl_program_split_draw (program);
           gsk_gl_program_set_uniform_texture (program,
                                               UNIFORM_SHARED_SOURCE,
                                               GL_TEXTURE_2D,
                                               GL_TEXTURE0,
                                               texture_id);
-          gsk_gl_program_begin_draw (program,
-                                     &job->viewport,
-                                     &job->projection,
-                                     gsk_gl_render_job_get_modelview_matrix (job),
-                                     gsk_gl_render_job_get_clip (job),
-                                     job->alpha);
           last_texture = texture_id;
         }