[PATCH weston] gl-renderer: Use EGL_KHR_no_config_context

[Armin Krezović]

This patch makes use of recently implemented
EGL_KHR_no_config_context extension in Mesa,
which superseeds EGL_MESA_configless_context.

See also (and the follow-up patch):

https://lists.freedesktop.org/archives/mesa-dev/2016-September/128510.html

Signed-off-by: Armin Krezović <krezovic.armin at gmail.com>
---
 libweston/gl-renderer.c    | 14 +++++++++++---
 libweston/weston-egl-ext.h |  3 +++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/libweston/gl-renderer.c b/libweston/gl-renderer.c
index 031576b..7ef7b89 100644
--- a/libweston/gl-renderer.c
+++ b/libweston/gl-renderer.c
@@ -199,6 +199,8 @@ struct gl_renderer {
 
 	int has_egl_buffer_age;
 
+	int has_no_config_context;
+
 	int has_configless_context;
 
 	int has_surfaceless_context;
@@ -2564,10 +2566,11 @@ gl_renderer_output_create(struct weston_output *output,
 	}
 
 	if (egl_config != gr->egl_config &&
+	    !gr->has_no_config_context &&
 	    !gr->has_configless_context) {
 		weston_log("attempted to use a different EGL config for an "
-			   "output but EGL_MESA_configless_context is not "
-			   "supported\n");
+			   "output but EGL_KHR_no_config_context or "
+			   "EGL_MESA_configless_context is not supported\n");
 		return -1;
 	}
 
@@ -2726,6 +2729,9 @@ gl_renderer_setup_egl_extensions(struct weston_compositor *ec)
 		weston_log("warning: EGL_EXT_swap_buffers_with_damage not "
 			   "supported. Performance could be affected.\n");
 
+	if (weston_check_egl_extension(extensions, "EGL_KHR_no_config_context"))
+		gr->has_no_config_context = 1;
+
 	if (weston_check_egl_extension(extensions, "EGL_MESA_configless_context"))
 		gr->has_configless_context = 1;
 
@@ -3101,7 +3107,9 @@ gl_renderer_setup(struct weston_compositor *ec, EGLSurface egl_surface)
 
 	context_config = gr->egl_config;
 
-	if (gr->has_configless_context)
+	if (gr->has_no_config_context)
+		context_config = EGL_NO_CONFIG_KHR;
+	else if (gr->has_configless_context)
 		context_config = EGL_NO_CONFIG_MESA;
 
 	gr->egl_context = eglCreateContext(gr->egl_display, context_config,
diff --git a/libweston/weston-egl-ext.h b/libweston/weston-egl-ext.h
index 6e36996..50964a8 100644
--- a/libweston/weston-egl-ext.h
+++ b/libweston/weston-egl-ext.h
@@ -152,5 +152,8 @@ typedef EGLSurface (EGLAPIENTRYP PFNEGLCREATEPLATFORMPIXMAPSURFACEEXTPROC) (EGLD
 #define EGL_PLATFORM_X11_KHR 0x31D5
 #endif
 
+#ifndef EGL_NO_CONFIG_KHR
+#define EGL_NO_CONFIG_KHR ((EGLConfig)0)
+#endif
 
 #endif
-- 
2.10.0