FindOpenGL¶

Finds the OpenGL and OpenGL Utility Library (GLU), for using OpenGL in a CMake project:

find_package(OpenGL [COMPONENTS <components>...] [...])

OpenGL (Open Graphics Library) is a cross-platform API for rendering 2D and 3D graphics. It is widely used in CAD, games, and visualization software.

GL refers to the core OpenGL library, which provides the fundamental graphics rendering API.
GLU (OpenGL Utility Library) is a companion library that offers utility functions built on top of OpenGL, such as tessellation and more complex shape drawing.

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 (GL Vendor-Neutral Dispatch library) support on Linux. See the Linux-specific section below.

Components¶

This module supports optional components which can be specified with the find_package() command:

find_package(OpenGL [COMPONENTS <components>...])

Supported components are:

EGL: 在 3.10 版被加入.

The EGL interface between OpenGL, OpenGL ES and the underlying windowing system.
GLX: 在 3.10 版被加入.

An extension to X that interfaces OpenGL, OpenGL ES with X window system.
OpenGL: 在 3.10 版被加入.

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¶

This module provides the following Imported Targets:

OpenGL::GL: 在 3.8 版被加入.

Target encapsulating the usage requirements of platform-specific OpenGL libraries, available if OpenGL is found.
OpenGL::GLU: 在 3.8 版被加入.

Target encapsulating the OpenGL Utility Library (GLU) usage requirements, available if GLU is found.

Additionally, the following GLVND-specific library imported targets are provided:

OpenGL::OpenGL: 在 3.10 版被加入.

Target encapsulating the libOpenGL usage requirements, available if system is GLVND-based and OpenGL is found.
OpenGL::GLX: 在 3.10 版被加入.

Target encapsulating the usage requirements of the OpenGL Extension to the the X Window System (GLX), available if OpenGL and GLX are found.
OpenGL::EGL: 在 3.10 版被加入.

Target encapsulating the EGL usage requirements, available if OpenGL and EGL are found.
OpenGL::GLES2: 在 3.27 版被加入.

Target encapsulating the GLES2 usage requirements, available if OpenGL and GLES2 are found.
OpenGL::GLES3: 在 3.27 版被加入.

Target encapsulating the GLES3 usage requirements, available if OpenGL and GLES3 are found.

結果變數¶

該模組定義了以下變數：

OpenGL_FOUND: 在 3.3 版被加入.

Boolean indicating whether OpenGL and all requested components were found.
OPENGL_XMESA_FOUND: Boolean indicating whether OpenGL XMESA was found.
OPENGL_GLU_FOUND: Boolean indicating whether GLU was found.
OpenGL_OpenGL_FOUND: 在 3.10 版被加入.

Boolean indicating whether the GLVND OpenGL library was found.
OpenGL_GLX_FOUND: 在 3.10 版被加入.

Boolean indicating whether GLVND GLX was found.
OpenGL_EGL_FOUND: 在 3.10 版被加入.

Boolean indicating whether GLVND EGL was found.
OpenGL_GLES2_FOUND: 在 3.27 版被加入.

Boolean indicating whether GLES2 was found.
OpenGL_GLES3_FOUND: 在 3.27 版被加入.

Boolean indicating whether GLES3 was found.
OPENGL_INCLUDE_DIRS: 在 3.29 版被加入.

Paths to the OpenGL include directories.
OPENGL_EGL_INCLUDE_DIRS: 在 3.10 版被加入.

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::* imported targets instead.

快取變數¶

The following cache variables may also be set:

OPENGL_INCLUDE_DIR: The path to the OpenGL include directory. The OPENGL_INCLUDE_DIRS variable is preferred.
OPENGL_GLU_INCLUDE_DIR: 在 3.29 版被加入.

Path to the OpenGL GLU include directory.
OPENGL_egl_LIBRARY: 在 3.10 版被加入.

Path to the GLVND EGL library.
OPENGL_glu_LIBRARY: Path to the GLU library.
OPENGL_glx_LIBRARY: 在 3.10 版被加入.

Path to the GLVND GLX library.
OPENGL_opengl_LIBRARY: 在 3.10 版被加入.

Path to the GLVND OpenGL library
OPENGL_gl_LIBRARY: Path to the OpenGL library.
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.

提示¶

該模組接受以下變數：

OpenGL_GL_PREFERENCE

在 3.10 版被加入.

This variable is supported on Linux systems 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.

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.

The OpenGL_GL_PREFERENCE variable may be set to specify the preferred way to provide legacy GL interfaces in case multiple choices are 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 using the CMAKE_FIND_FRAMEWORK variable. 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.

已棄用的變數¶

The following variables are provided for backward compatibility:

OPENGL_FOUND: 在 4.2 版之後被棄用: Use OpenGL_FOUND, which has the same value.

Boolean indicating whether OpenGL and all requested components were found.

範例¶

Finding the OpenGL library and linking it to a project target:

find_package(OpenGL)
target_link_libraries(project_target PRIVATE OpenGL::OpenGL)

另請參見¶

The FindGLEW module to find OpenGL Extension Wrangler Library (GLEW).
The FindGLUT module to find OpenGL Utility Toolkit (GLUT) library.
The FindVulkan module to find Vulkan graphics API.