log CGLErrorString for CGLChoosePixelFormat, enable OpenGL

multithreading

https://developer.apple.com/library/mac/technotes/tn2085/_index.html

1 files changed, 7 insertions, 1 deletions

diff --git a/common/headless_view.cpp b/common/headless_view.cpp
index 61531bfd65..10888f7a76 100644
--- a/common/headless_view.cpp
+++ b/common/headless_view.cpp
@@ -20,7 +20,7 @@ HeadlessView::HeadlessView() {
     GLint num;
     CGLError error = CGLChoosePixelFormat(attributes, &pixelFormat, &num);
     if (error) {
-        fprintf(stderr, "Error pixel format\n");
+        fprintf(stderr, "Error pixel format: %s\n", CGLErrorString(error));
         return;
     }
 
@@ -30,6 +30,12 @@ HeadlessView::HeadlessView() {
         fprintf(stderr, "Error creating GL context object\n");
         return;
     }
+
+    error = CGLEnable(gl_context, kCGLCEMPEngine);
+    if (error != kCGLNoError ) {
+        fprintf(stderr, "Error enabling OpenGL multithreading\n");
+        return;
+    }
 #endif
 
 #if MBGL_USE_GLX