[core] Abstract the OpenGL implementation

The platform will be responsible to load the OpenGL implementation
and give the function pointers to Mapbox GL Core. The platform might
load OpenGL by linking against some OpenGL implementation, load it
dynamically, etc. It doesn't matter as long as it is a valid
implementation.

Also adds the `::platform` namespace where all the missing symbols and
interfaces expected to be implemented by the platforms will live.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/mbgl/platform/gl_functions.cpp b/src/mbgl/platform/gl_functions.cpp
new file mode 100644
index 0000000000..6eb7790ca2
--- /dev/null
+++ b/src/mbgl/platform/gl_functions.cpp
@@ -0,0 +1,17 @@
+#include <mbgl/platform/gl_functions.hpp>
+
+#include <mbgl/util/logging.hpp>
+
+namespace mbgl {
+namespace platform {
+
+#ifndef NDEBUG
+void glCheckError(const char* cmd, const char* file, int line) {
+    if (GLenum err = glGetError()) {
+        Log::Warning(Event::OpenGL, "Error %d: %s - %s:%d", err, cmd, file, line);
+    }
+}
+#endif
+
+}  // namespace platform
+}  // namespace mbgl