ui/egl-helpers.c | 53
+++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 47 insertions(+), 6 deletions(-)
diff --git a/ui/egl-helpers.c b/ui/egl-helpers.c
index 584dd1b..48686cf 100644
--- a/ui/egl-helpers.c
+++ b/ui/egl-helpers.c
@@ -192,6 +192,51 @@ EGLSurface qemu_egl_init_surface_x11(EGLContext ectx,
Window win)
/* ----------------------------------------------------------------------
*/
+/*
+ * Taken from glamor_egl.h from the Xorg xserver, which is MIT licensed
+ *
+ * Create an EGLDisplay from a native display type. This is a little
quirky
+ * for a few reasons.
+ *
+ * 1: GetPlatformDisplayEXT and GetPlatformDisplay are the API you want to
+ * use, but have different function signatures in the third argument; this
+ * happens not to matter for us, at the moment, but it means epoxy won't
alias
+ * them together.
+ *
+ * 2: epoxy 1.3 and earlier don't understand EGL client extensions, which
+ * means you can't call "eglGetPlatformDisplayEXT" directly, as the
resolver
+ * will crash.
+ *
+ * 3: You can't tell whether you have EGL 1.5 at this point, because
+ * eglQueryString(EGL_VERSION) is a property of the display, which we
don't
+ * have yet. So you have to query for extensions no matter what.
Fortunately
+ * epoxy_has_egl_extension _does_ let you query for client extensions, so
+ * we don't have to write our own extension string parsing.
+ *
+ * 4. There is no EGL_KHR_platform_base to complement the EXT one, thus
one
+ * needs to know EGL 1.5 is supported in order to use the
eglGetPlatformDisplay
+ * function pointer.
+ * We can workaround this (circular dependency) by probing for the EGL 1.5
+ * platform extensions (EGL_KHR_platform_gbm and friends) yet it doesn't
seem
+ * like mesa will be able to adverise these (even though it can do EGL
1.5).
+ */
+static EGLDisplay qemu_egl_get_display(void *native)
+{
+#ifdef EGL_PLATFORM_GBM_MESA
+ /* In practise any EGL 1.5 implementation would support the EXT
extension */
+ if (epoxy_has_egl_extension(NULL, "EGL_EXT_platform_base")) {
+ PFNEGLGETPLATFORMDISPLAYEXTPROC getPlatformDisplayEXT =
+ (void *) eglGetProcAddress("eglGetPlatformDisplayEXT");
+ if (getPlatformDisplayEXT) {
+ return getPlatformDisplayEXT(EGL_PLATFORM_GBM_MESA, native,
NULL);
+ }
+ }
+#endif
+
+ /* fallback */
+ return eglGetDisplay(native);
+}
+
int qemu_egl_init_dpy(EGLNativeDisplayType dpy, bool gles, bool debug)
{
static const EGLint conf_att_gl[] = {
@@ -222,12 +267,8 @@ int qemu_egl_init_dpy(EGLNativeDisplayType dpy, bool
gles, bool debug)
setenv("LIBGL_DEBUG", "verbose", true);
}
- egl_dbg("eglGetDisplay (dpy %p) ...\n", dpy);
-#ifdef EGL_MESA_platform_gbm
- qemu_egl_display = eglGetPlatformDisplayEXT(EGL_PLATFORM_GBM_MESA,
dpy, NULL);
-#else
- qemu_egl_display = eglGetDisplay(dpy);
-#endif
+ egl_dbg("qemu_egl_get_display (dpy %p) ...\n", dpy);
+ qemu_egl_display = qemu_egl_get_display(dpy);
if (qemu_egl_display == EGL_NO_DISPLAY) {
error_report("egl: eglGetDisplay failed");
return -1;
--
1.8.3.1
--