From 06f66b29158fa6e13db243886d02a1aa2c17b93a Mon Sep 17 00:00:00 2001
From: Nigel Stewart <nigels@users.sourceforge.net>
Date: Wed, 27 Jan 2016 22:46:59 +1000
Subject: [PATCH] EGL glewinfo now working for both Nvidia and Mesa
 implementations

---
 auto/src/glewinfo_tail.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/auto/src/glewinfo_tail.c b/auto/src/glewinfo_tail.c
index 1975286..30f25fd 100644
--- a/auto/src/glewinfo_tail.c
+++ b/auto/src/glewinfo_tail.c
@@ -185,11 +185,11 @@ GLboolean glewCreateContext (struct createParams *params)
   EGLint numDevices;
   EGLSurface  surface;
   EGLint majorVersion, minorVersion;
-  static const EGLint configAttribs[] = {
+  EGLint configAttribs[] = {
+        EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
         EGL_RED_SIZE, 1,
         EGL_GREEN_SIZE, 1,
         EGL_BLUE_SIZE, 1,
-        EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
         EGL_RENDERABLE_TYPE, EGL_OPENGL_BIT,
         EGL_NONE
    };
@@ -204,7 +204,7 @@ GLboolean glewCreateContext (struct createParams *params)
   };
   EGLConfig config;
   EGLint numConfig;
-  EGLint error;
+  EGLBoolean pBuffer;
 
   PFNEGLQUERYDEVICESEXTPROC       queryDevices = NULL;
   PFNEGLGETPLATFORMDISPLAYEXTPROC getPlatformDisplay = NULL;
@@ -233,17 +233,22 @@ GLboolean glewCreateContext (struct createParams *params)
   if (!getError || !getDisplay || !initialize || !bindAPI || !chooseConfig || !createWindowSurface || !createContext || !makeCurrent)
     return GL_TRUE;
 
+  pBuffer = 0;
   display = EGL_NO_DISPLAY;
   if (queryDevices && getPlatformDisplay)
   {
     queryDevices(1, devices, &numDevices);
     if (numDevices==1)
     {
+      /* Nvidia EGL doesn't need X11 for p-buffer surface */
       display = getPlatformDisplay(EGL_PLATFORM_DEVICE_EXT, devices[0], 0);
+      configAttribs[1] = EGL_PBUFFER_BIT;
+      pBuffer = 1;
     }
   }
   if (display==EGL_NO_DISPLAY)
   {
+    /* Fall-back to X11 surface, works on Mesa */
     display = getDisplay(EGL_DEFAULT_DISPLAY);
   }
   if (display == EGL_NO_DISPLAY)
@@ -257,13 +262,13 @@ GLboolean glewCreateContext (struct createParams *params)
   if (chooseConfig(display, configAttribs, &config, 1, &numConfig) != EGL_TRUE || (numConfig != 1))
     return GL_TRUE;
 
-  ctx = createContext(display, config, EGL_NO_CONTEXT, contextAttribs);
+  ctx = createContext(display, config, EGL_NO_CONTEXT, pBuffer ? contextAttribs : NULL);
   if (NULL == ctx)
     return GL_TRUE;
 
   surface = EGL_NO_SURFACE;
   /* Create a p-buffer surface if possible */
-  if (createPbufferSurface)
+  if (pBuffer && createPbufferSurface)
   {
     surface = createPbufferSurface(display, config, pBufferAttribs);
   }
@@ -272,19 +277,14 @@ GLboolean glewCreateContext (struct createParams *params)
   {
     surface = createWindowSurface(display, config, (EGLNativeWindowType) NULL, NULL);
   }
+#if 0
   if (surface == EGL_NO_SURFACE)
     return GL_TRUE;
+#endif
 
   if (makeCurrent(display, surface, surface, ctx) != EGL_TRUE)
     return GL_TRUE;
 
-  error = getError();
-  if (error!=EGL_SUCCESS)
-  {
-    printf("eglGetError: %d\n", error);
-    return GL_TRUE;
-  }
-
   return GL_FALSE;
 }