test: Add script to generate source file for testing vsync

Courtesy of an original script by Mark Schreiber,
https://bugs.freedesktop.org/show_bug.cgi?id=59606

test/Makefile.am

@@ -35,4 +35,11 @@ libtest_la_SOURCES = \
 	dri2.h \
 	$(NULL)
 
-EXTRA_DIST = README
+vsync.avi: mkvsync.sh
+	./mkvsync.sh $@
+
+clean-vsync-avi:
+	rm -rf vsync.avi .build.tmp
+
+EXTRA_DIST = README mkvsync.sh
+clean-local: clean-vsync-avi

test/mkvsync.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+OUT="$1"
+[ -n "$OUT" ] || OUT="vsync.avi"
+
+TMP=".build.tmp"
+
+rm -rf ${TMP}
+mkdir ${TMP}
+convert -size 640x480 -depth 24 canvas:black png24:${TMP}/black.png
+convert -size 640x480 -depth 24 canvas:white png24:${TMP}/white.png
+
+mkdir ${TMP}/anim
+
+for ((a=0; $a < 1000; a=$a+2)); do
+	ln -s ../black.png ${TMP}/anim/$a.png
+done
+
+for ((a=1; $a < 1000; a=$a+2)); do
+	ln -s ../white.png ${TMP}/anim/$a.png
+done
+
+mencoder "mf://${TMP}/anim/*.png" -v -vf-clr -mf fps=60 -o "${OUT}" -ovc lavc
+exitcode=$?
+rm -rf ${TMP}
+
+exit ${exitcode}