Check whether swap interval value is supported

[gltest.git] / eglbackend.cpp

diff --git a/eglbackend.cpp b/eglbackend.cpp
index 359d54ac0d133d9a10e2b84588fb02a24dcb445e..04165c761460cedb93a6d99203a5b367a01381e4 100644 (file)
--- a/eglbackend.cpp
+++ b/eglbackend.cpp
@@ -1,3 +1,21 @@
+/* gltest - small OpenGL tearing test program
+ * Copyright (C) 2012-2013 Ralf Jung <post@ralfj.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
 #include "eglbackend.h"
 
 #include <stdlib.h>
@@ -94,11 +112,26 @@ EGLBackend::~EGLBackend()
 void EGLBackend::swapBuffers() const
 {
        assert(context != EGL_NO_CONTEXT); // this implies the display is also initialized
-       eglSwapBuffers(display, surface);
+       if (eglSwapBuffers(display, surface) == EGL_FALSE)
+               exitEglError("Failed to swap buffers");
 }
 
 void EGLBackend::setSwapInterval(int i) const
 {
        assert(context != EGL_NO_CONTEXT);
-       eglSwapInterval(display, i);
+       // check if swap interval value is supported
+       EGLint val;
+       eglGetConfigAttrib(display, config, EGL_MIN_SWAP_INTERVAL, &val);
+       if (i < val) {
+               fprintf(stderr, "Cannot set swap interval to %d, minimum supported value is %d\n", i, val);
+               exit(1);
+       }
+       eglGetConfigAttrib(display, config, EGL_MAX_SWAP_INTERVAL, &val);
+       if (i > val) {
+               fprintf(stderr, "Cannot set swap interval to %d, maximum supported value is %d\n", i, val);
+               exit(1);
+       }
+       // use it
+       if (eglSwapInterval(display, i) == EGL_FALSE)
+               exitEglError("Failed to set swap interval");
 }