[v2, weston] gl-renderer.c: Use gr->egl_config to create pbuffer surface

[Madhurkiran Harikrishnan]

The original implementation always chose first egl config for pbuffer
surface type, however the returned configs are implementation specific
and egl config may not always match between ctx and surface. Hence,
use gr->egl_config which already has the matching config but ensure that
windows and pbuffer bit are set for the surface type.

Signed-off-by: Madhurkiran Harikrishnan <madhurkiran.harikrishnan at xilinx.com>
---
 libweston/gl-renderer.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/libweston/gl-renderer.c b/libweston/gl-renderer.c
index da29b07..c1e0bca 100644
--- a/libweston/gl-renderer.c
+++ b/libweston/gl-renderer.c
@@ -3146,17 +3146,7 @@ output_handle_destroy(struct wl_listener *listener, void *data)
 
 static int
 gl_renderer_create_pbuffer_surface(struct gl_renderer *gr) {
-	EGLConfig pbuffer_config;
-
-	static const EGLint pbuffer_config_attribs[] = {
-		EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
-		EGL_RED_SIZE, 1,
-		EGL_GREEN_SIZE, 1,
-		EGL_BLUE_SIZE, 1,
-		EGL_ALPHA_SIZE, 0,
-		EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
-		EGL_NONE
-	};
+	EGLint surface_type;
 
 	static const EGLint pbuffer_attribs[] = {
 		EGL_WIDTH, 10,
@@ -3164,13 +3154,21 @@ gl_renderer_create_pbuffer_surface(struct gl_renderer *gr) {
 		EGL_NONE
 	};
 
-	if (egl_choose_config(gr, pbuffer_config_attribs, NULL, 0, &pbuffer_config) < 0) {
-		weston_log("failed to choose EGL config for PbufferSurface\n");
+
+	if(!eglGetConfigAttrib(gr->egl_display, gr->egl_config, EGL_SURFACE_TYPE, &surface_type)) {
+		weston_log("failed to get surface type for PbufferSurface\n");
+	}
+
+	if (!((surface_type & EGL_WINDOW_BIT) && (surface_type & EGL_PBUFFER_BIT)) &&
+	    !gr->has_configless_context) {
+		weston_log("attempted to use a different EGL config for an "
+			   "output but EGL_KHR_no_config_context or "
+			   "EGL_MESA_configless_context is not supported\n");
 		return -1;
 	}
 
 	gr->dummy_surface = eglCreatePbufferSurface(gr->egl_display,
-						    pbuffer_config,
+						    gr->egl_config,
 						    pbuffer_attribs);
 
 	if (gr->dummy_surface == EGL_NO_SURFACE) {
-- 
2.7.4