[cogl/wip/wayland-compositor: 4/18] Add internal _cogl_get_proc_address

[Robert Bragg <rbragg src gnome org>]

commit 14a88f009e3672732765c737982be0ed2a1fd146
Author: Robert Bragg <robert linux intel com>
Date:   Tue May 24 01:38:48 2011 +0100

    Add internal _cogl_get_proc_address
    
    This adds an internal _cogl_get_proc_address that doesn't need a
    CoglContext. This will enable us to check driver features earlier.

 cogl/cogl-feature-private.c       |   35 ++++++++++++++++-------------------
 cogl/cogl-feature-private.h       |    3 ++-
 cogl/cogl.c                       |   22 +---------------------
 cogl/driver/gl/cogl-gl.c          |   19 ++-----------------
 cogl/driver/gles/cogl-gles.c      |   19 ++-----------------
 cogl/winsys/cogl-winsys-egl.c     |   21 ++-------------------
 cogl/winsys/cogl-winsys-glx.c     |   21 ++-------------------
 cogl/winsys/cogl-winsys-private.h |    4 ++++
 cogl/winsys/cogl-winsys-wgl.c     |    3 ++-
 cogl/winsys/cogl-winsys.c         |   31 +++++++++++++++++++++++++++++++
 10 files changed, 64 insertions(+), 114 deletions(-)
---
diff --git a/cogl/cogl-feature-private.c b/cogl/cogl-feature-private.c
index d3904b4..1b60afd 100644
--- a/cogl/cogl-feature-private.c
+++ b/cogl/cogl-feature-private.c
@@ -33,7 +33,8 @@
 #include "cogl-feature-private.h"
 
 gboolean
-_cogl_feature_check (const char *driver_prefix,
+_cogl_feature_check (const CoglWinsysVtable *winsys,
+                     const char *driver_prefix,
                      const CoglFeatureData *data,
                      unsigned int gl_major,
                      unsigned int gl_minor,
@@ -44,8 +45,6 @@ _cogl_feature_check (const char *driver_prefix,
   const char *suffix = NULL;
   int func_num;
 
-  _COGL_GET_CONTEXT (ctx, FALSE);
-
   /* First check whether the functions should be directly provided by
      GL */
   if (COGL_CHECK_GL_VERSION (gl_major, gl_minor,
@@ -107,7 +106,7 @@ _cogl_feature_check (const char *driver_prefix,
   /* If we couldn't find anything that provides the functions then
      give up */
   if (suffix == NULL)
-    return FALSE;
+    goto error;
 
   /* Try to get all of the entry points */
   for (func_num = 0; data->functions[func_num].name; func_num++)
@@ -117,28 +116,26 @@ _cogl_feature_check (const char *driver_prefix,
 
       full_function_name = g_strconcat (data->functions[func_num].name,
                                         suffix, NULL);
-      func = cogl_get_proc_address (full_function_name);
+      func = _cogl_get_proc_address (winsys, full_function_name);
       g_free (full_function_name);
 
       if (func == NULL)
-        break;
+        goto error;
 
       /* Set the function pointer in the context */
       *(void **) ((guint8 *) function_table +
                   data->functions[func_num].pointer_offset) = func;
     }
 
-  /* If one of the functions wasn't found then we should set all of
-     the function pointers back to NULL so that the rest of Cogl can
-     safely do feature testing by just looking at the function
-     pointers */
-  if (data->functions[func_num].name)
-    {
-      while (func_num-- > 0)
-        *(void **) ((guint8 *) ctx +
-                    data->functions[func_num].pointer_offset) = NULL;
-      return FALSE;
-    }
-  else
-    return TRUE;
+  return TRUE;
+
+  /* If the extension isn't found or one of the functions wasn't found
+   * then set all of the functions pointers to NULL so Cogl can safely
+   * do feature testing by just looking at the function pointers */
+error:
+  for (func_num = 0; data->functions[func_num].name; func_num++)
+    *(void **) ((guint8 *) function_table +
+                data->functions[func_num].pointer_offset) = NULL;
+
+  return FALSE;
 }
diff --git a/cogl/cogl-feature-private.h b/cogl/cogl-feature-private.h
index 5d0101e..5b26b70 100644
--- a/cogl/cogl-feature-private.h
+++ b/cogl/cogl-feature-private.h
@@ -71,7 +71,8 @@ struct _CoglFeatureData
 };
 
 gboolean
-_cogl_feature_check (const char *driver_prefix,
+_cogl_feature_check (const CoglWinsysVtable *winsys,
+                     const char *driver_prefix,
                      const CoglFeatureData *data,
                      unsigned int gl_major,
                      unsigned int gl_minor,
diff --git a/cogl/cogl.c b/cogl/cogl.c
index 896b2e6..07cc76d 100644
--- a/cogl/cogl.c
+++ b/cogl/cogl.c
@@ -30,7 +30,6 @@
 #include <string.h>
 #include <math.h>
 #include <stdlib.h>
-#include <gmodule.h>
 
 #include "cogl-debug.h"
 #include "cogl-internal.h"
@@ -93,32 +92,13 @@ cogl_gl_error_to_string (GLenum error_code)
 CoglFuncPtr
 cogl_get_proc_address (const char* name)
 {
-  void *address;
-  static GModule *module = NULL;
   const CoglWinsysVtable *winsys;
 
   _COGL_GET_CONTEXT (ctx, NULL);
 
   winsys = _cogl_context_get_winsys (ctx);
 
-  address = winsys->get_proc_address (name);
-  if (address)
-    return address;
-
-  /* this should find the right function if the program is linked against a
-   * library providing it */
-  if (G_UNLIKELY (module == NULL))
-    module = g_module_open (NULL, 0);
-
-  if (module)
-    {
-      gpointer symbol;
-
-      if (g_module_symbol (module, name, &symbol))
-        return symbol;
-    }
-
-  return NULL;
+  return _cogl_get_proc_address (winsys, name);
 }
 
 gboolean
diff --git a/cogl/driver/gl/cogl-gl.c b/cogl/driver/gl/cogl-gl.c
index c738806..ce81a6a 100644
--- a/cogl/driver/gl/cogl-gl.c
+++ b/cogl/driver/gl/cogl-gl.c
@@ -148,20 +148,6 @@ static const CoglFeatureData cogl_feature_data[] =
 #include "cogl-feature-functions-gl.h"
   };
 
-#undef COGL_FEATURE_BEGIN
-#define COGL_FEATURE_BEGIN(a, b, c, d, e, f, g)
-#undef COGL_FEATURE_FUNCTION
-#define COGL_FEATURE_FUNCTION(ret, name, args) \
-  context->drv.pf_ ## name = NULL;
-#undef COGL_FEATURE_END
-#define COGL_FEATURE_END()
-
-static void
-initialize_function_table (CoglContext *context)
-{
-  #include "cogl-feature-functions-gl.h"
-}
-
 /* Query the GL extensions and lookup the corresponding function
  * pointers. Theoretically the list of extensions can change for
  * different GL contexts so it is the winsys backend's responsiblity
@@ -220,10 +206,9 @@ _cogl_gl_update_features (CoglContext *context)
   if (max_clip_planes >= 4)
     flags |= COGL_FEATURE_FOUR_CLIP_PLANES;
 
-  initialize_function_table (context);
-
   for (i = 0; i < G_N_ELEMENTS (cogl_feature_data); i++)
-    if (_cogl_feature_check ("GL", cogl_feature_data + i,
+    if (_cogl_feature_check (_cogl_context_get_winsys (context),
+                             "GL", cogl_feature_data + i,
                              gl_major, gl_minor,
                              gl_extensions,
                              context))
diff --git a/cogl/driver/gles/cogl-gles.c b/cogl/driver/gles/cogl-gles.c
index 09d0382..080efeb 100644
--- a/cogl/driver/gles/cogl-gles.c
+++ b/cogl/driver/gles/cogl-gles.c
@@ -70,20 +70,6 @@ static const CoglFeatureData cogl_feature_data[] =
 #include "cogl-feature-functions-gles.h"
   };
 
-#undef COGL_FEATURE_BEGIN
-#define COGL_FEATURE_BEGIN(a, b, c, d, e, f, g)
-#undef COGL_FEATURE_FUNCTION
-#define COGL_FEATURE_FUNCTION(ret, name, args) \
-  context->drv.pf_ ## name = NULL;
-#undef COGL_FEATURE_END
-#define COGL_FEATURE_END()
-
-static void
-initialize_function_table (CoglContext *context)
-{
-  #include "cogl-feature-functions-gles.h"
-}
-
 /* Query the GL extensions and lookup the corresponding function
  * pointers. Theoretically the list of extensions can change for
  * different GL contexts so it is the winsys backend's responsiblity
@@ -137,10 +123,9 @@ _cogl_gl_update_features (CoglContext *context)
   /* Both GLES 1.1 and GLES 2.0 support point sprites in core */
   flags |= COGL_FEATURE_POINT_SPRITE;
 
-  initialize_function_table (context);
-
   for (i = 0; i < G_N_ELEMENTS (cogl_feature_data); i++)
-    if (_cogl_feature_check ("GL", cogl_feature_data + i,
+    if (_cogl_feature_check (_cogl_context_get_winsys (context),
+                             "GL", cogl_feature_data + i,
                              0, 0,
                              gl_extensions,
                              context))
diff --git a/cogl/winsys/cogl-winsys-egl.c b/cogl/winsys/cogl-winsys-egl.c
index 49b1965..d9da042 100644
--- a/cogl/winsys/cogl-winsys-egl.c
+++ b/cogl/winsys/cogl-winsys-egl.c
@@ -195,22 +195,6 @@ _cogl_winsys_get_proc_address (const char *name)
   return (CoglFuncPtr) eglGetProcAddress (name);
 }
 
-#undef COGL_WINSYS_FEATURE_BEGIN
-#define COGL_WINSYS_FEATURE_BEGIN(a, b, c, d, e, f)
-#undef COGL_WINSYS_FEATURE_FUNCTION
-#define COGL_WINSYS_FEATURE_FUNCTION(ret, name, args) \
-  egl_renderer->pf_ ## name = NULL;
-#undef COGL_WINSYS_FEATURE_END
-#define COGL_WINSYS_FEATURE_END()
-
-static void
-initialize_function_table (CoglRenderer *renderer)
-{
-  CoglRendererEGL *egl_renderer = renderer->winsys;
-
-#include "cogl-winsys-egl-feature-functions.h"
-}
-
 #ifdef COGL_HAS_EGL_PLATFORM_ANDROID_SUPPORT
 static ANativeWindow *android_native_window;
 
@@ -494,10 +478,9 @@ update_winsys_features (CoglContext *context)
                   TRUE);
 #endif
 
-  initialize_function_table (context->display->renderer);
-
   for (i = 0; i < G_N_ELEMENTS (winsys_feature_data); i++)
-    if (_cogl_feature_check ("EGL", winsys_feature_data + i, 0, 0,
+    if (_cogl_feature_check (_cogl_context_get_winsys (context),
+                             "EGL", winsys_feature_data + i, 0, 0,
                              egl_extensions,
                              egl_renderer))
       {
diff --git a/cogl/winsys/cogl-winsys-glx.c b/cogl/winsys/cogl-winsys-glx.c
index 412f8fe..74a3668 100644
--- a/cogl/winsys/cogl-winsys-glx.c
+++ b/cogl/winsys/cogl-winsys-glx.c
@@ -178,22 +178,6 @@ _cogl_winsys_get_proc_address (const char *name)
   return NULL;
 }
 
-#undef COGL_WINSYS_FEATURE_BEGIN
-#define COGL_WINSYS_FEATURE_BEGIN(a, b, c, d, e, f)
-#undef COGL_WINSYS_FEATURE_FUNCTION
-#define COGL_WINSYS_FEATURE_FUNCTION(ret, name, args) \
-  glx_renderer->pf_ ## name = NULL;
-#undef COGL_WINSYS_FEATURE_END
-#define COGL_WINSYS_FEATURE_END()
-
-static void
-initialize_function_table (CoglRenderer *renderer)
-{
-  CoglRendererGLX *glx_renderer = renderer->winsys;
-
-#include "cogl-winsys-glx-feature-functions.h"
-}
-
 static CoglOnscreen *
 find_onscreen_for_xid (CoglContext *context, guint32 xid)
 {
@@ -361,10 +345,9 @@ update_winsys_features (CoglContext *context)
                   COGL_WINSYS_FEATURE_MULTIPLE_ONSCREEN,
                   TRUE);
 
-  initialize_function_table (context->display->renderer);
-
   for (i = 0; i < G_N_ELEMENTS (winsys_feature_data); i++)
-    if (_cogl_feature_check ("GLX", winsys_feature_data + i, 0, 0,
+    if (_cogl_feature_check (_cogl_context_get_winsys (context),
+                             "GLX", winsys_feature_data + i, 0, 0,
                              glx_extensions,
                              glx_renderer))
       {
diff --git a/cogl/winsys/cogl-winsys-private.h b/cogl/winsys/cogl-winsys-private.h
index 2208a86..a8aaf90 100644
--- a/cogl/winsys/cogl-winsys-private.h
+++ b/cogl/winsys/cogl-winsys-private.h
@@ -154,4 +154,8 @@ typedef struct _CoglWinsysVtable
 gboolean
 _cogl_winsys_has_feature (CoglWinsysFeature feature);
 
+CoglFuncPtr
+_cogl_get_proc_address (const CoglWinsysVtable *winsys,
+                        const char *name);
+
 #endif /* __COGL_WINSYS_PRIVATE_H */
diff --git a/cogl/winsys/cogl-winsys-wgl.c b/cogl/winsys/cogl-winsys-wgl.c
index 8c2cb7e..9eb9e87 100644
--- a/cogl/winsys/cogl-winsys-wgl.c
+++ b/cogl/winsys/cogl-winsys-wgl.c
@@ -566,7 +566,8 @@ update_winsys_features (CoglContext *context)
       COGL_NOTE (WINSYS, "  WGL Extensions: %s", wgl_extensions);
 
       for (i = 0; i < G_N_ELEMENTS (winsys_feature_data); i++)
-        if (_cogl_feature_check ("WGL", winsys_feature_data + i, 0, 0,
+        if (_cogl_feature_check (_cogl_context_get_winsys (context),
+                                 "WGL", winsys_feature_data + i, 0, 0,
                                  wgl_extensions,
                                  wgl_renderer))
           {
diff --git a/cogl/winsys/cogl-winsys.c b/cogl/winsys/cogl-winsys.c
index 547ea5a..e75b906 100644
--- a/cogl/winsys/cogl-winsys.c
+++ b/cogl/winsys/cogl-winsys.c
@@ -29,6 +29,8 @@
 #include "cogl.h"
 #include "cogl-context-private.h"
 
+#include <gmodule.h>
+
 GQuark
 _cogl_winsys_error_quark (void)
 {
@@ -43,3 +45,32 @@ _cogl_winsys_has_feature (CoglWinsysFeature feature)
 
   return COGL_FLAGS_GET (ctx->winsys_features, feature);
 }
+
+/* XXX: we would call this _cogl_winsys_get_proc_address but that
+ * currently collides with the per winsys implementation names we use.
+ * */
+CoglFuncPtr
+_cogl_get_proc_address (const CoglWinsysVtable *winsys,
+                        const char *name)
+{
+  void *address = winsys->get_proc_address (name);
+  static GModule *module = NULL;
+
+  if (address)
+    return address;
+
+  /* this should find the right function if the program is linked against a
+   * library providing it */
+  if (G_UNLIKELY (module == NULL))
+    module = g_module_open (NULL, 0);
+
+  if (module)
+    {
+      gpointer symbol;
+
+      if (g_module_symbol (module, name, &symbol))
+        return symbol;
+    }
+
+  return NULL;
+}