[cogl/cogl-1.12] Make the default driver selectable at configure time

[Robert Bragg <rbragg src gnome org>]

commit cde0eb3e762d14c6b9f1c1b34bbb525332cbda89
Author: Sjoerd Simons <sjoerd simons collabora co uk>
Date:   Wed Jun 20 09:47:41 2012 +0200

    Make the default driver selectable at configure time
    
    When building COGL with multiple backends it can be useful to force a
    default driver to be selected. For example while for Debian we do want to
    build the GL renderer on ARM, GLESv2 is much more suitable as the
    default renderer on that platform.
    
    Reviewed-by: Robert Bragg <robert linux intel com>
    
    (cherry picked from commit 8a43aa7167b56784f7b50c557391b990861d594f)

 cogl/Makefile.am     |    6 ++++++
 cogl/cogl-renderer.c |    5 +++++
 configure.ac         |   15 ++++++++++++++-
 3 files changed, 25 insertions(+), 1 deletions(-)
---
diff --git a/cogl/Makefile.am b/cogl/Makefile.am
index 31c7f19..a73d3f8 100644
--- a/cogl/Makefile.am
+++ b/cogl/Makefile.am
@@ -32,6 +32,12 @@ AM_CPPFLAGS = \
 	-DCOGL_LOCALEDIR=\""$(localedir)"\" \
 	$(NULL)
 
+if HAVE_COGL_DEFAULT_DRIVER
+AM_CPPFLAGS += \
+	-DCOGL_DEFAULT_DRIVER=\"$(COGL_DEFAULT_DRIVER)\"
+endif
+
+
 AM_CFLAGS = $(COGL_DEP_CFLAGS) $(COGL_EXTRA_CFLAGS) $(MAINTAINER_CFLAGS)
 
 BUILT_SOURCES += cogl-defines.h cogl-egl-defines.h cogl-gl-header.h
diff --git a/cogl/cogl-renderer.c b/cogl/cogl-renderer.c
index 82e45b6..d47e972 100644
--- a/cogl/cogl-renderer.c
+++ b/cogl/cogl-renderer.c
@@ -260,6 +260,11 @@ _cogl_renderer_choose_driver (CoglRenderer *renderer,
         }
     }
 
+#ifdef COGL_DEFAULT_DRIVER
+  if (!driver_name)
+    driver_name = COGL_DEFAULT_DRIVER;
+#endif
+
 #ifdef HAVE_COGL_GL
   if (renderer->driver_override == COGL_DRIVER_GL ||
       (renderer->driver_override == COGL_DRIVER_ANY &&
diff --git a/configure.ac b/configure.ac
index 893cc46..c262c0d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -612,7 +612,7 @@ AM_CONDITIONAL([COGL_DRIVER_GL_SUPPORTED], [test "x$enable_gl" = "xyes"])
 AM_CONDITIONAL([COGL_DRIVER_GLES_SUPPORTED],
                [test "x$enable_gles1" = "xyes" || test "x$enable_gles2" = "xyes"])
 
-dnl Allow the GL library names to be overridden with configure options
+dnl Allow the GL library names and default driver to be overridden with configure options
 AC_ARG_WITH([gl-libname],
             [AS_HELP_STRING([--with-gl-libname],
                             override the name of the GL library to dlopen)],
@@ -625,6 +625,15 @@ AC_ARG_WITH([gles2-libname],
             [AS_HELP_STRING([--with-gles2-libname],
                             override the name of the GLESv2 library to dlopen)],
             [COGL_GLES2_LIBNAME="$withval"])
+AC_ARG_WITH([default-driver],
+            [AS_HELP_STRING([--with-default-driver],
+                            specify a default cogl driver)],
+            [COGL_DEFAULT_DRIVER="${withval}"],
+            [COGL_DEFAULT_DRIVER="" ])
+
+AM_CONDITIONAL(HAVE_COGL_DEFAULT_DRIVER,
+  [ test "x$COGL_DEFAULT_DRIVER" != "x" ])
+
 
 AC_SUBST([COGL_GL_LIBNAME])
 AC_SUBST([HAVE_GL])
@@ -632,6 +641,7 @@ AC_SUBST([COGL_GLES1_LIBNAME])
 AC_SUBST([HAVE_GLES1])
 AC_SUBST([COGL_GLES2_LIBNAME])
 AC_SUBST([HAVE_GLES2])
+AC_SUBST([COGL_DEFAULT_DRIVER])
 
 if test "x$GL_LIBRARY_DIRECTLY_LINKED" = "xyes"; then
    AC_DEFINE([HAVE_DIRECTLY_LINKED_GL_LIBRARY], [1],
@@ -1234,6 +1244,9 @@ echo "Cogl - $COGL_1_VERSION/$COGL_VERSION (${COGL_RELEASE_STATUS})"
 echo ""
 echo " â Global:"
 echo "        Prefix: ${prefix}"
+if test "x$COGL_DEFAULT_DRIVER" != "x"; then
+echo "        Default driver: ${COGL_DEFAULT_DRIVER}"
+fi
 
 echo ""
 # Features