[gtk] gsk: Improve GSK_RENDERER behavior

[Benjamin Otte <otte src gnome org>]

commit 69644993f608d1822f3a27554741ab3fc1bc9685
Author: Benjamin Otte <otte redhat com>
Date:   Mon May 7 16:45:32 2018 +0200

    gsk: Improve GSK_RENDERER behavior
    
    1. Include the broadway renderer (so we can test it properly fails on
       Wayland or X11)
    2. List all potential renderers, print useful information when Vulkan
       is not compiled in instea dof omitting it
    3. Improve docs

 docs/reference/gtk/running.sgml | 23 +++++++++++++++++------
 gsk/gskrenderer.c               | 11 +++++++++++
 2 files changed, 28 insertions(+), 6 deletions(-)
---
diff --git a/docs/reference/gtk/running.sgml b/docs/reference/gtk/running.sgml
index a001ffec28..90ec4178f6 100644
--- a/docs/reference/gtk/running.sgml
+++ b/docs/reference/gtk/running.sgml
@@ -465,22 +465,33 @@ nevertheless.
 
   <para>
     If set, selects the GSK renderer to use. The following renderers can
-    be selected, provided they are included in the GSK libraries you are using:
+    be selected, provided they are included in the GTK library you are using
+    and the GDK backend supports them:
     <variablelist>
 
       <varlistentry>
-        <term>vulkan</term>
-        <listitem><para>Selects the Vulkan renderer</para></listitem>
+        <term>help</term>
+        <listitem><para>Prints information about available options</para></listitem>
       </varlistentry>
 
       <varlistentry>
-        <term>gl</term>
-        <listitem><para>Selects the Vulkan renderer</para></listitem>
+        <term>broadway</term>
+        <listitem><para>Selects the Broadway-backend specific renderer</para></listitem>
       </varlistentry>
 
       <varlistentry>
         <term>cairo</term>
-        <listitem><para>Selects the cairo renderer</para></listitem>
+        <listitem><para>Selects the fallback Cairo renderer</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term>gl</term>
+        <listitem><para>Selects the default OpenGL renderer</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term>vulkan</term>
+        <listitem><para>Selects the Vulkan renderer</para></listitem>
       </varlistentry>
 
     </variablelist>
diff --git a/gsk/gskrenderer.c b/gsk/gskrenderer.c
index 9c10209b53..11b8cd2074 100644
--- a/gsk/gskrenderer.c
+++ b/gsk/gskrenderer.c
@@ -545,6 +545,10 @@ get_renderer_for_name (const char *renderer_name)
 {
   if (renderer_name == NULL)
     return G_TYPE_INVALID;
+#ifdef GDK_WINDOWING_BROADWAY
+  else if (g_ascii_strcasecmp (renderer_name, "broadway") == 0)
+    return GSK_TYPE_BROADWAY_RENDERER;
+#endif
   else if (g_ascii_strcasecmp (renderer_name, "cairo") == 0)
     return GSK_TYPE_CAIRO_RENDERER;
   else if (g_ascii_strcasecmp (renderer_name, "opengl") == 0
@@ -557,10 +561,17 @@ get_renderer_for_name (const char *renderer_name)
   else if (g_ascii_strcasecmp (renderer_name, "help") == 0)
     {
       g_print ("Supported arguments for GSK_RENDERER environment variable:\n");
+#ifdef GDK_WINDOWING_BROADWAY
+      g_print ("broadway - Use the Broadway specific renderer\n");
+#else
+      g_print ("broadway - disabled during GTK build\n");
+#endif
       g_print ("   cairo - Use the Cairo fallback renderer\n");
       g_print ("  opengl - Use the default OpenGL renderer\n");
 #ifdef GDK_RENDERING_VULKAN
       g_print ("  vulkan - Use the Vulkan renderer\n");
+#else
+      g_print ("  vulkan - Disabled during GTK build\n");
 #endif
       g_print ("    help - Print this help\n\n");
       g_print ("Other arguments will cause a warning and be ignored.\n");