Getting an error on make with SDL

[kimslawson]

I'm running El Capitan, OS X 10.11.6. I installed updated versions of glew and libpng via homebrew.

Though I have SDL installed I'm getting the following error on make:

In file included from ./cglutils.h:1:
./GL/glew.h:36:12: fatal error: 'SDL/SDL_opengl.h' file not found

and also

In file included from ./common.h:42:
./cglutils.h:1:10: error: 'GL/glew.h' file not found with include; use
"quotes" instead

which I resolved by changing the <> to ""