[cogl] egl: pass EGL_NO_CONTEXT to eglCreateImage for tfp

[Robert Bragg <rbragg src gnome org>]

commit 6e6620e089fdb4f0a09f645c8789f7726c22eedf
Author: Robert Bragg <robert linux intel com>
Date:   Thu Jul 21 00:52:07 2011 +0100

    egl: pass EGL_NO_CONTEXT to eglCreateImage for tfp
    
    When passing the EGL_NATIVE_PIXMAP_KHR target to eglCreateImage the
    EGL_KHR_image_pixmap extension explicitly states that EGL_NO_CONTEXT
    must also be passed so we are now careful to do this.
    
    Reviewed-by: Neil Roberts <neil linux intel com>

 cogl/winsys/cogl-winsys-egl.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)
---
diff --git a/cogl/winsys/cogl-winsys-egl.c b/cogl/winsys/cogl-winsys-egl.c
index 14de1e3..2c84ff6 100644
--- a/cogl/winsys/cogl-winsys-egl.c
+++ b/cogl/winsys/cogl-winsys-egl.c
@@ -1809,11 +1809,21 @@ _cogl_egl_create_image (CoglContext *ctx,
 {
   CoglDisplayEGL *egl_display = ctx->display->winsys;
   CoglRendererEGL *egl_renderer = ctx->display->renderer->winsys;
+  EGLContext egl_ctx;
 
   g_return_val_if_fail (egl_renderer->pf_eglCreateImage, EGL_NO_IMAGE_KHR);
 
+  /* The EGL_KHR_image_pixmap spec explicitly states that EGL_NO_CONTEXT must
+   * always be used in conjunction with the EGL_NATIVE_PIXMAP_KHR target */
+#ifdef EGL_KHR_image_pixmap
+  if (target == EGL_NATIVE_PIXMAP_KHR)
+    egl_ctx = EGL_NO_CONTEXT;
+  else
+#endif
+    egl_ctx = egl_display->egl_context;
+
   return egl_renderer->pf_eglCreateImage (egl_renderer->edpy,
-                                          egl_display->egl_context,
+                                          egl_ctx,
                                           target,
                                           buffer,
                                           attribs);