From 92d3b1692f11658cad027cd597019eabd65faf89 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Wed, 3 Apr 2013 15:27:29 +0200
Subject: [PATCH] Check whether swap interval value is supported

---
 eglbackend.cpp | 19 +++++++++++++++++--
 glwindow.cpp   |  2 --
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/eglbackend.cpp b/eglbackend.cpp
index 0e4c937..04165c7 100644
--- a/eglbackend.cpp
+++ b/eglbackend.cpp
@@ -112,11 +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");
 }
diff --git a/glwindow.cpp b/glwindow.cpp
index 2d79639..ca6dbb9 100644
--- a/glwindow.cpp
+++ b/glwindow.cpp
@@ -124,8 +124,6 @@ void GLWindow::exec()
 					if (strcmp(XGetAtomName(display, event.xclient.message_type), "WM_PROTOCOLS") == 0 &&
 						strcmp(XGetAtomName(display, event.xclient.data.l[0]), "WM_DELETE_WINDOW") == 0)
 					{
-						XDestroyWindow(display, window);
-						window = 0;
 						return;
 					}
 					break;
-- 
2.30.2