diff -up SDL2-2.0.9/include/SDL_opengl_glext.h.khrplatform SDL2-2.0.9/include/SDL_opengl_glext.h

--- SDL2-2.0.9/include/SDL_opengl_glext.h.khrplatform	2019-02-15 20:22:39.173773779 -0500

+++ SDL2-2.0.9/include/SDL_opengl_glext.h	2019-02-15 20:22:58.176399330 -0500

@@ -469,8 +469,9 @@ GLAPI void APIENTRY glBlendEquation (GLe

 typedef long GLsizeiptr;

 typedef long GLintptr;

 #else

-typedef ptrdiff_t GLsizeiptr;

-typedef ptrdiff_t GLintptr;

+#include <KHR/khrplatform.h>

+typedef khronos_intptr_t GLintptr;

+typedef khronos_ssize_t GLsizeiptr;

 #endif

 #define GL_BUFFER_SIZE                    0x8764

 #define GL_BUFFER_USAGE                   0x8765