[gtk: 1/2] Switch to GL_ARB_framebuffer_object

[Matthias Clasen <matthiasc src gnome org>]

commit 404d79153eb33d2d85e3c40d371e70292175f2d8
Author: Emmanuel Gil Peyrot <linkmauve linkmauve fr>
Date:   Fri Jun 12 15:08:44 2020 +0200

    Switch to GL_ARB_framebuffer_object
    
    GTK 4.0 was currently using GL_EXT_framebuffer_object, which is
    deprecated as the ARB version has been merged into OpenGL 3.0 as well as
    OpenGL ES 2.0, and provides laxer requirements.
    
    This is a port of !2076 for 4.x.

 gdk/gdkgl.c     | 14 +++++++-------
 gtk/gtkglarea.c | 28 ++++++++++++++--------------
 2 files changed, 21 insertions(+), 21 deletions(-)
---
diff --git a/gdk/gdkgl.c b/gdk/gdkgl.c
index dcaae81f3b..6ea045b9b0 100644
--- a/gdk/gdkgl.c
+++ b/gdk/gdkgl.c
@@ -348,7 +348,7 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
   paint_data = gdk_gl_context_get_paint_data (paint_context);
 
   if (paint_data->tmp_framebuffer == 0)
-    glGenFramebuffersEXT (1, &paint_data->tmp_framebuffer);
+    glGenFramebuffers (1, &paint_data->tmp_framebuffer);
 
   if (source_type == GL_RENDERBUFFER)
     {
@@ -390,19 +390,19 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
   cairo_surface_set_device_scale (image, buffer_scale, buffer_scale);
 
   framebuffer = paint_data->tmp_framebuffer;
-  glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, framebuffer);
+  glBindFramebuffer (GL_FRAMEBUFFER, framebuffer);
 
   if (source_type == GL_RENDERBUFFER)
     {
       /* Create a framebuffer with the source renderbuffer and
          make it the current target for reads */
-      glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
-                                    GL_RENDERBUFFER_EXT, source);
+      glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                                 GL_RENDERBUFFER, source);
     }
   else
     {
-      glFramebufferTexture2DEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
-                                 GL_TEXTURE_2D, source, 0);
+      glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                              GL_TEXTURE_2D, source, 0);
     }
 
   glPixelStorei (GL_PACK_ALIGNMENT, 4);
@@ -418,7 +418,7 @@ gdk_cairo_draw_from_gl (cairo_t              *cr,
 
   glPixelStorei (GL_PACK_ROW_LENGTH, 0);
 
-  glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0);
+  glBindFramebuffer (GL_FRAMEBUFFER, 0);
 
   cairo_surface_mark_dirty (image);
 
diff --git a/gtk/gtkglarea.c b/gtk/gtkglarea.c
index c91cc1e427..107e0940ff 100644
--- a/gtk/gtkglarea.c
+++ b/gtk/gtkglarea.c
@@ -366,17 +366,17 @@ gtk_gl_area_ensure_buffers (GtkGLArea *area)
 
   priv->have_buffers = TRUE;
 
-  glGenFramebuffersEXT (1, &priv->frame_buffer);
+  glGenFramebuffers (1, &priv->frame_buffer);
 
   if ((priv->has_depth_buffer || priv->has_stencil_buffer))
     {
       if (priv->depth_stencil_buffer == 0)
-        glGenRenderbuffersEXT (1, &priv->depth_stencil_buffer);
+        glGenRenderbuffers (1, &priv->depth_stencil_buffer);
     }
   else if (priv->depth_stencil_buffer != 0)
     {
       /* Delete old depth/stencil buffer */
-      glDeleteRenderbuffersEXT (1, &priv->depth_stencil_buffer);
+      glDeleteRenderbuffers (1, &priv->depth_stencil_buffer);
       priv->depth_stencil_buffer = 0;
     }
 
@@ -549,20 +549,20 @@ gtk_gl_area_attach_buffers (GtkGLArea *area)
   else if (priv->needs_resize)
     gtk_gl_area_allocate_buffers (area);
 
-  glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, priv->frame_buffer);
+  glBindFramebuffer (GL_FRAMEBUFFER, priv->frame_buffer);
 
   if (priv->texture != NULL)
-    glFramebufferTexture2D (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
+    glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                             GL_TEXTURE_2D, priv->texture->id, 0);
 
   if (priv->depth_stencil_buffer)
     {
       if (priv->has_depth_buffer)
-        glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
-                                      GL_RENDERBUFFER_EXT, priv->depth_stencil_buffer);
+        glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
+                                   GL_RENDERBUFFER, priv->depth_stencil_buffer);
       if (priv->has_stencil_buffer)
-        glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT,
-                                      GL_RENDERBUFFER_EXT, priv->depth_stencil_buffer);
+        glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
+                                   GL_RENDERBUFFER, priv->depth_stencil_buffer);
     }
 }
 
@@ -578,14 +578,14 @@ gtk_gl_area_delete_buffers (GtkGLArea *area)
 
   if (priv->depth_stencil_buffer != 0)
     {
-      glDeleteRenderbuffersEXT (1, &priv->depth_stencil_buffer);
+      glDeleteRenderbuffers (1, &priv->depth_stencil_buffer);
       priv->depth_stencil_buffer = 0;
     }
 
   if (priv->frame_buffer != 0)
     {
-      glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0);
-      glDeleteFramebuffersEXT (1, &priv->frame_buffer);
+      glBindFramebuffer (GL_FRAMEBUFFER, 0);
+      glDeleteFramebuffers (1, &priv->frame_buffer);
       priv->frame_buffer = 0;
     }
 }
@@ -716,8 +716,8 @@ gtk_gl_area_snapshot (GtkWidget   *widget,
  else
    glDisable (GL_DEPTH_TEST);
 
-  status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
-  if (status == GL_FRAMEBUFFER_COMPLETE_EXT)
+  status = glCheckFramebufferStatus (GL_FRAMEBUFFER);
+  if (status == GL_FRAMEBUFFER_COMPLETE)
     {
       Texture *texture;