chjj/compton #7: Patch to add SGI_video_sync to mpv

mpv-0.1.7-sgi-video-sync.patch

diff -x '*~' -x '.*.sw?' -ru mpv-0.1.7.orig/video/out/gl_common.c mpv-0.1.7/video/out/gl_common.c
--- mpv-0.1.7.orig/video/out/gl_common.c	2013-09-24 22:58:11.829840182 +0800
+++ mpv-0.1.7/video/out/gl_common.c	2013-09-24 23:05:09.749834728 +0800
@@ -362,6 +362,15 @@
             {0}
         },
     },
+    // SGI_video_sync
+    {
+        .extension = "SGI_video_sync",
+        .functions = (struct gl_function[]) {
+            DEF_FN_NAMES(GetVideoSync, "glXGetVideoSyncSGI"),
+            DEF_FN_NAMES(WaitVideoSync, "glXWaitVideoSyncSGI"),
+            {0}
+        },
+    },
     // GL legacy functions in GL 1.x - 2.x, removed from GL 3.x
     {
         .ver_core = MPGL_VER(1, 1),
diff -x '*~' -x '.*.sw?' -ru mpv-0.1.7.orig/video/out/gl_common.h mpv-0.1.7/video/out/gl_common.h
--- mpv-0.1.7.orig/video/out/gl_common.h	2013-09-24 22:58:11.829840182 +0800
+++ mpv-0.1.7/video/out/gl_common.h	2013-09-24 23:06:39.699833554 +0800
@@ -259,6 +259,8 @@
     void (GLAPIENTRY *ProgramEnvParameter4f)(GLenum, GLuint, GLfloat, GLfloat,
                                              GLfloat, GLfloat);
     int (GLAPIENTRY *SwapInterval)(int);
+    int (GLAPIENTRY *WaitVideoSync) (int, int, unsigned *);
+    int (GLAPIENTRY *GetVideoSync) (unsigned *);
     void (GLAPIENTRY *TexImage3D)(GLenum, GLint, GLenum, GLsizei, GLsizei,
                                   GLsizei, GLint, GLenum, GLenum,
                                   const GLvoid *);
diff -x '*~' -x '.*.sw?' -ru mpv-0.1.7.orig/video/out/gl_x11.c mpv-0.1.7/video/out/gl_x11.c
--- mpv-0.1.7.orig/video/out/gl_x11.c	2013-09-24 22:58:11.829840182 +0800
+++ mpv-0.1.7/video/out/gl_x11.c	2013-09-24 23:10:57.179830194 +0800
@@ -298,6 +298,11 @@
 
 static void swapGlBuffers_x11(MPGLContext *ctx)
 {
+    if (ctx->gl->GetVideoSync && ctx->gl->WaitVideoSync) {
+        unsigned vblank_count = 0;
+        ctx->gl->GetVideoSync(&vblank_count);
+        ctx->gl->WaitVideoSync(2, (vblank_count + 1) % 2, &vblank_count);
+    }
     glXSwapBuffers(ctx->vo->x11->display, ctx->vo->x11->window);
 }