opengl: add egl-context.[ch] helpers

Add helper functions to manage opengl contexts using egl.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

ui/egl-context.c

@@ -0,0 +1,34 @@
+#include "qemu-common.h"
+#include "ui/egl-context.h"
+
+QEMUGLContext qemu_egl_create_context(DisplayChangeListener *dcl,
+                                      QEMUGLParams *params)
+{
+   EGLContext ctx;
+   EGLint ctx_att[] = {
+      EGL_CONTEXT_CLIENT_VERSION, params->major_ver,
+      EGL_CONTEXT_MINOR_VERSION_KHR, params->minor_ver,
+      EGL_NONE
+   };
+
+   ctx = eglCreateContext(qemu_egl_display, qemu_egl_config,
+                          eglGetCurrentContext(), ctx_att);
+   return ctx;
+}
+
+void qemu_egl_destroy_context(DisplayChangeListener *dcl, QEMUGLContext ctx)
+{
+    eglDestroyContext(qemu_egl_display, ctx);
+}
+
+int qemu_egl_make_context_current(DisplayChangeListener *dcl,
+                                  QEMUGLContext ctx)
+{
+   return eglMakeCurrent(qemu_egl_display,
+                         EGL_NO_SURFACE, EGL_NO_SURFACE, ctx);
+}
+
+QEMUGLContext qemu_egl_get_current_context(DisplayChangeListener *dcl)
+{
+    return eglGetCurrentContext();
+}