FindOpenGL

FindModule for OpenGL and GLU.

Optional COMPONENTS

This module respects several optional COMPONENTS: EGL, GLX, and OpenGL. There are corresponding import targets for each of these flags.

IMPORTED Targets

This module defines the IMPORTED targets:

OpenGL::GL
Defined to the platform-specific OpenGL libraries if the system has OpenGL.
OpenGL::OpenGL
Defined to libOpenGL if the system is GLVND-based. OpenGL::GL
OpenGL::GLU
Defined if the system has GLU.
OpenGL::GLX
Defined if the system has GLX.
OpenGL::EGL
Defined if the system has EGL.

Result Variables

This module sets the following variables:

OPENGL_FOUND
True, if the system has OpenGL and all components are found.
OPENGL_XMESA_FOUND
True, if the system has XMESA.
OPENGL_GLU_FOUND
True, if the system has GLU.
OpenGL_OpenGL_FOUND
True, if the system has an OpenGL library.
OpenGL_GLX_FOUND
True, if the system has GLX.
OpenGL_EGL_FOUND
True, if the system has EGL.
OPENGL_INCLUDE_DIR
Path to the OpenGL include directory.
OPENGL_EGL_INCLUDE_DIRS
Path to the EGL include directory.
OPENGL_LIBRARIES
Paths to the OpenGL library, windowing system libraries, and GLU libraries. On Linux, this assumes GLX and is never correct for EGL-based targets. Clients are encouraged to use the OpenGL::* import targets instead.

Cache variables

The following cache variables may also be set:

OPENGL_egl_LIBRARY
Path to the EGL library.
OPENGL_glu_LIBRARY
Path to the GLU library.
OPENGL_glx_LIBRARY
Path to the GLVND ‘GLX’ library.
OPENGL_opengl_LIBRARY
Path to the GLVND ‘OpenGL’ library
OPENGL_gl_LIBRARY
Path to the OpenGL library. New code should prefer the OpenGL::* import targets.

Linux-specific

Some Linux systems utilize GLVND as a new ABI for OpenGL. GLVND separates context libraries from OpenGL itself; OpenGL lives in “libOpenGL”, and contexts are defined in “libGLX” or “libEGL”. GLVND is currently the only way to get OpenGL 3+ functionality via EGL in a manner portable across vendors. Projects may use GLVND explicitly with target OpenGL::OpenGL and either OpenGL::GLX or OpenGL::EGL.

Projects may use the OpenGL::GL target (or OPENGL_LIBRARIES variable) to use legacy GL interfaces. These will use the legacy GL library located by OPENGL_gl_LIBRARY, if available. If OPENGL_gl_LIBRARY is empty or not found and GLVND is available, the OpenGL::GL target will use GLVND OpenGL::OpenGL and OpenGL::GLX (and the OPENGL_LIBRARIES variable will use the corresponding libraries). Thus, for non-EGL-based Linux targets, the OpenGL::GL target is most portable.

A OpenGL_GL_PREFERENCE variable may be set to specify the preferred way to provide legacy GL interfaces in case multiple choices are available. The value may be one of:

GLVND
If the GLVND OpenGL and GLX libraries are available, prefer them. This forces OPENGL_gl_LIBRARY to be empty. This is the default if components were requested (since components correspond to GLVND libraries).
LEGACY
Prefer to use the legacy libGL library, if available. This is the default if no components were requested.

For EGL targets the client must rely on GLVND support on the user’s system. Linking should use the OpenGL::OpenGL OpenGL::EGL targets. Using GLES* libraries is theoretically possible in place of OpenGL::OpenGL, but this module does not currently support that; contributions welcome.

OPENGL_egl_LIBRARY and OPENGL_EGL_INCLUDE_DIRS are defined in the case of GLVND. For non-GLVND Linux and other systems these are left undefined.

macOS-Specific

On OSX FindOpenGL defaults to using the framework version of OpenGL. People will have to change the cache values of OPENGL_glu_LIBRARY and OPENGL_gl_LIBRARY to use OpenGL with X11 on OSX.