From 10a1b9808253dc67e19db2a0c4c360788b9e668e Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Sun, 30 Jun 2019 00:39:23 +0200
Subject: vo_gpu: x11egl: support Mesa OML sync extension

Mesa supports the EGL_CHROMIUM_sync_control extension, and it's
available out of the box with AMD drivers. In practice, this is exactly
the same as GLX_OML_sync_control, but for EGL. The extension
specification is separate from the GLX one though, and buried somewhere
in the Chromium code.

This appears to work, although I don't know if it really works.

In theory, this could be useful for other EGL targets. Support code for
it could have been added to egl_helpers.c to avoid some minor duplicated
glue code if another EGL target were to provide this extension. I didn't
bother with that. ANGLE on Windows can't support it, because the
extension spec. explicitly requires POSIX timers. ANGLE on Linux/OSX is
actively harmful for mpv and hopefully won't ever use it. Wayland uses
EGL, but has its own fancy presentation feedback stuff (and besides, I
don't think basic video player functionality works on Wayland at all).
context_drm_egl maybe? But I think DRM has its own stuff.
---
 video/out/opengl/context_x11egl.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'video/out')

diff --git a/video/out/opengl/context_x11egl.c b/video/out/opengl/context_x11egl.c
index 32530cc11d..b1aa0690d7 100644
--- a/video/out/opengl/context_x11egl.c
+++ b/video/out/opengl/context_x11egl.c
@@ -30,12 +30,18 @@
 #include "video/out/x11_common.h"
 #include "context.h"
 #include "egl_helpers.h"
+#include "oml_sync.h"
+#include "utils.h"
 
 struct priv {
     GL gl;
     EGLDisplay egl_display;
     EGLContext egl_context;
     EGLSurface egl_surface;
+
+    EGLBoolean (*GetSyncValues)(EGLDisplay, EGLSurface,
+                                int64_t*, int64_t*, int64_t*);
+    struct oml_sync sync;
 };
 
 static void mpegl_uninit(struct ra_ctx *ctx)
@@ -79,6 +85,19 @@ static void mpegl_swap_buffers(struct ra_ctx *ctx)
 {
     struct priv *p = ctx->priv;
     eglSwapBuffers(p->egl_display, p->egl_surface);
+
+    int64_t ust, msc, sbc;
+    if (!p->GetSyncValues || !p->GetSyncValues(p->egl_display, p->egl_surface,
+                                               &ust, &msc, &sbc))
+        ust = msc = sbc = -1;
+
+    oml_sync_swap(&p->sync, ust, msc, sbc);
+}
+
+static void mpegl_get_vsync(struct ra_ctx *ctx, struct vo_vsync_info *info)
+{
+    struct priv *p = ctx->priv;
+    oml_sync_get_info(&p->sync, info);
 }
 
 static bool mpegl_init(struct ra_ctx *ctx)
@@ -142,11 +161,16 @@ static bool mpegl_init(struct ra_ctx *ctx)
 
     struct ra_gl_ctx_params params = {
         .swap_buffers = mpegl_swap_buffers,
+        .get_vsync    = mpegl_get_vsync,
     };
 
     if (!ra_gl_ctx_init(ctx, &p->gl, params))
         goto uninit;
 
+    const char *exts = eglQueryString(eglGetCurrentDisplay(), EGL_EXTENSIONS);
+    if (gl_check_extension(exts, "EGL_CHROMIUM_sync_control"))
+        p->GetSyncValues = (void *)eglGetProcAddress("eglGetSyncValuesCHROMIUM");
+
     ra_add_native_resource(ctx->ra, "x11", vo->x11->display);
 
     return true;
-- 
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