[cogl] renderer: Adds getters/setters for driver preference

[Robert Bragg <rbragg src gnome org>]

commit be237cc2b7a02ad8b4ec78fe1a495e1b616e8688
Author: Robert Bragg <robert linux intel com>
Date:   Thu Feb 23 16:41:27 2012 +0000

    renderer: Adds getters/setters for driver preference
    
    This adds api for explicitly choosing what underlying driver cogl should
    use internally for rendering as well as api for querying back what
    driver is actually in use.
    
    Reviewed-by: Neil Roberts <neil linux intel com>

 cogl/cogl-internal.h              |    7 ----
 cogl/cogl-renderer-private.h      |    1 +
 cogl/cogl-renderer.c              |   27 ++++++++++++++++--
 cogl/cogl-renderer.h              |   56 +++++++++++++++++++++++++++++++++++++
 cogl/winsys/cogl-winsys-egl-kms.c |    2 +
 5 files changed, 83 insertions(+), 10 deletions(-)
---
diff --git a/cogl/cogl-internal.h b/cogl/cogl-internal.h
index 0cc2f9b..5c9a097 100644
--- a/cogl/cogl-internal.h
+++ b/cogl/cogl-internal.h
@@ -92,13 +92,6 @@ typedef enum { /*< prefix=COGL_DRIVER_ERROR >*/
 
 typedef enum
 {
-  COGL_DRIVER_GL,
-  COGL_DRIVER_GLES1,
-  COGL_DRIVER_GLES2
-} CoglDriver;
-
-typedef enum
-{
   COGL_PRIVATE_FEATURE_TEXTURE_2D_FROM_EGL_IMAGE = 1L<<0,
   COGL_PRIVATE_FEATURE_MESA_PACK_INVERT = 1L<<1,
   COGL_PRIVATE_FEATURE_STENCIL_BUFFER = 1L<<2,
diff --git a/cogl/cogl-renderer-private.h b/cogl/cogl-renderer-private.h
index bdc505d..11dc0bb 100644
--- a/cogl/cogl-renderer-private.h
+++ b/cogl/cogl-renderer-private.h
@@ -42,6 +42,7 @@ struct _CoglRenderer
 {
   CoglObject _parent;
   gboolean connected;
+  CoglDriver driver_override;
   const CoglWinsysVtable *winsys_vtable;
   CoglWinsysID winsys_id_override;
   GList *constraints;
diff --git a/cogl/cogl-renderer.c b/cogl/cogl-renderer.c
index 2af1f74..1c6a28b 100644
--- a/cogl/cogl-renderer.c
+++ b/cogl/cogl-renderer.c
@@ -245,7 +245,9 @@ _cogl_renderer_choose_driver (CoglRenderer *renderer,
     driver_name = _cogl_config_driver;
 
 #ifdef HAVE_COGL_GL
-  if (driver_name == NULL || !g_ascii_strcasecmp (driver_name, "gl"))
+  if (renderer->driver_override == COGL_DRIVER_GL ||
+      (renderer->driver_override == COGL_DRIVER_ANY &&
+       (driver_name == NULL || !g_ascii_strcasecmp (driver_name, "gl"))))
     {
       renderer->driver = COGL_DRIVER_GL;
       libgl_name = COGL_GL_LIBNAME;
@@ -254,7 +256,9 @@ _cogl_renderer_choose_driver (CoglRenderer *renderer,
 #endif
 
 #ifdef HAVE_COGL_GLES2
-  if (driver_name == NULL || !g_ascii_strcasecmp (driver_name, "gles2"))
+  if (renderer->driver_override == COGL_DRIVER_GLES2 ||
+      (renderer->driver_override == COGL_DRIVER_ANY &&
+       (driver_name == NULL || !g_ascii_strcasecmp (driver_name, "gles2"))))
     {
       renderer->driver = COGL_DRIVER_GLES2;
       libgl_name = COGL_GLES2_LIBNAME;
@@ -263,7 +267,9 @@ _cogl_renderer_choose_driver (CoglRenderer *renderer,
 #endif
 
 #ifdef HAVE_COGL_GLES
-  if (driver_name == NULL || !g_ascii_strcasecmp (driver_name, "gles1"))
+  if (renderer->driver_override == COGL_DRIVER_GLES1 ||
+      (renderer->driver_override == COGL_DRIVER_ANY &&
+       (driver_name == NULL || !g_ascii_strcasecmp (driver_name, "gles1"))))
     {
       renderer->driver = COGL_DRIVER_GLES1;
       libgl_name = COGL_GLES1_LIBNAME;
@@ -505,3 +511,18 @@ cogl_renderer_remove_constraint (CoglRenderer *renderer,
                                          GUINT_TO_POINTER (constraint));
 }
 
+void
+cogl_renderer_set_driver (CoglRenderer *renderer,
+                          CoglDriver driver)
+{
+  _COGL_RETURN_IF_FAIL (!renderer->connected);
+  renderer->driver_override = driver;
+}
+
+CoglDriver
+cogl_renderer_get_driver (CoglRenderer *renderer)
+{
+  _COGL_RETURN_VAL_IF_FAIL (renderer->connected, 0);
+
+  return renderer->driver;
+}
diff --git a/cogl/cogl-renderer.h b/cogl/cogl-renderer.h
index 06b0f5c..6332327 100644
--- a/cogl/cogl-renderer.h
+++ b/cogl/cogl-renderer.h
@@ -319,6 +319,62 @@ void
 cogl_renderer_remove_constraint (CoglRenderer *renderer,
                                  CoglRendererConstraint constraint);
 
+/**
+ * CoglDriver:
+ * @COGL_DRIVER_ANY: Implies no preference for which driver is used
+ * @COGL_DRIVER_GL: An OpenGL driver.
+ * @COGL_DRIVER_GLES1: An OpenGL ES 1.1 driver.
+ * @COGL_DRIVER_GLES2: An OpenGL ES 2.0 driver.
+ *
+ * Identifiers for underlying hardware drivers that may be used by
+ * Cogl for rendering.
+ *
+ * Since: 1.10
+ * Stability: unstable
+ */
+typedef enum
+{
+  COGL_DRIVER_ANY,
+  COGL_DRIVER_GL,
+  COGL_DRIVER_GLES1,
+  COGL_DRIVER_GLES2
+} CoglDriver;
+
+/**
+ * cogl_renderer_set_driver:
+ * @renderer: An unconnected #CoglRenderer
+ *
+ * Requests that Cogl should try to use a specific underlying driver
+ * for rendering.
+ *
+ * If you select an unsupported driver then cogl_renderer_connect()
+ * will fail and report an error. Most applications should not
+ * explicitly select a driver and should rely on Cogl automatically
+ * choosing the driver.
+ *
+ * This may only be called on an un-connected #CoglRenderer.
+ *
+ * Since: 1.10
+ * Stability: unstable
+ */
+void
+cogl_renderer_set_driver (CoglRenderer *renderer,
+                          CoglDriver driver);
+
+/**
+ * cogl_renderer_get_driver:
+ * @renderer: A connected #CoglRenderer
+ *
+ * Queries what underlying driver is being used by Cogl.
+ *
+ * This may only be called on a connected #CoglRenderer.
+ *
+ * Since: 1.10
+ * Stability: unstable
+ */
+CoglDriver
+cogl_renderer_get_driver (CoglRenderer *renderer);
+
 G_END_DECLS
 
 #endif /* __COGL_RENDERER_H__ */
diff --git a/cogl/winsys/cogl-winsys-egl-kms.c b/cogl/winsys/cogl-winsys-egl-kms.c
index 7864bd2..1f42fe5 100644
--- a/cogl/winsys/cogl-winsys-egl-kms.c
+++ b/cogl/winsys/cogl-winsys-egl-kms.c
@@ -178,6 +178,8 @@ _cogl_winsys_egl_display_setup (CoglDisplay *display,
       surfaceless_feature = COGL_EGL_WINSYS_FEATURE_SURFACELESS_GLES2;
       surfaceless_feature_name = "gles2";
       break;
+    case COGL_DRIVER_ANY:
+      g_return_val_if_reached (FALSE);
     }
 
   if (!(egl_renderer->private_features & surfaceless_feature))