SDL_opengl: Fix Mac build with new glext.h
diff --git a/include/SDL_opengl.h b/include/SDL_opengl.h
index 2a639b9..d89185b 100644
--- a/include/SDL_opengl.h
+++ b/include/SDL_opengl.h
@@ -50,6 +50,7 @@
#define __glext_h_ /* Don't let gl.h include glext.h */
#endif
#if defined(__MACOSX__)
+#include <stddef.h> /* Needed for ptrdiff_t */
#include <OpenGL/gl.h> /* Header File For The OpenGL Library */
#define __X_GL_H
#else
diff --git a/src/render/opengl/SDL_render_gl.c b/src/render/opengl/SDL_render_gl.c
index 20a7f66..643f248 100644
--- a/src/render/opengl/SDL_render_gl.c
+++ b/src/render/opengl/SDL_render_gl.c
@@ -332,7 +332,7 @@ GL_ResetState(SDL_Renderer *renderer)
}
static void APIENTRY
-GL_HandleDebugMessage(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const char *message, void *userParam)
+GL_HandleDebugMessage(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const char *message, const void *userParam)
{
SDL_Renderer *renderer = (SDL_Renderer *) userParam;
GL_RenderData *data = (GL_RenderData *) renderer->driverdata;