FindOpenGL

FindModule for OpenGL and OpenGL Utility Library (GLU).

在 3.2 版的變更: X11 is no longer added as a dependency on Unix/Linux systems.

在 3.10 版被加入: GLVND support on Linux. See the Linux-specific section below.

Optional COMPONENTS

在 3.10 版被加入.

This module respects several optional COMPONENTS:

EGL

The EGL interface between OpenGL, OpenGL ES and the underlying windowing system.

GLX

An extension to X that interfaces OpenGL, OpenGL ES with X window system.

OpenGL

The cross platform API for 3D graphics.

GLES2

在 3.27 版被加入.

A subset of OpenGL API for embedded systems with limited capabilities.

GLES3

在 3.27 版被加入.

A subset of OpenGL API for embedded systems with more capabilities.

Imported Targets

在 3.8 版被加入.

This module defines the IMPORTED targets:

OpenGL::GL

Defined to the platform-specific OpenGL libraries if the system has OpenGL.

OpenGL::GLU

Defined if the system has OpenGL Utility Library (GLU).

在 3.10 版被加入: Additionally, the following GLVND-specific library targets are defined:

OpenGL::OpenGL

Defined to libOpenGL if the system is GLVND-based.

OpenGL::GLX

Defined if the system has OpenGL Extension to the X Window System (GLX).

OpenGL::EGL

Defined if the system has EGL.

OpenGL::GLES2

在 3.27 版被加入.

Defined if the system has GLES2.

OpenGL::GLES3

在 3.27 版被加入.

Defined if the system has GLES3.

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::GLES2

Defined if the system has GLES2.

OpenGL::GLES3

Defined if the system has GLES3.

OPENGL_INCLUDE_DIR

Path to the OpenGL include directory. The OPENGL_INCLUDE_DIRS variable is preferred.

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.

OPENGL_INCLUDE_DIRS

在 3.29 版被加入.

Paths to the OpenGL include directories.

在 3.10 版被加入: Variables for GLVND-specific libraries OpenGL, EGL and GLX.

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.

OPENGL_gles2_LIBRARY

在 3.27 版被加入.

Path to the OpenGL GLES2 library.

OPENGL_gles3_LIBRARY

在 3.27 版被加入.

Path to the OpenGL GLES3 library.

OPENGL_GLU_INCLUDE_DIR

在 3.29 版被加入.

Path to the OpenGL GLU include directory.

在 3.10 版被加入: Variables for GLVND-specific libraries OpenGL, EGL and GLX.

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.

在 3.11 版的變更: This is the default, unless policy CMP0072 is set to OLD and no components are requested (since components correspond to GLVND libraries).

LEGACY

Prefer to use the legacy libGL library, if available.

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 macOS this module defaults to using the macOS-native framework version of OpenGL. To use the X11 version of OpenGL on macOS, one can disable searching of frameworks. For example:

find_package(X11)
if(APPLE AND X11_FOUND)
  set(CMAKE_FIND_FRAMEWORK NEVER)
  find_package(OpenGL)
  unset(CMAKE_FIND_FRAMEWORK)
else()
  find_package(OpenGL)
endif()

An end user building this project may need to point CMake at their X11 installation, e.g., with -DOpenGL_ROOT=/opt/X11.