1# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
2# file Copyright.txt or https://cmake.org/licensing for details.
3
4#[=======================================================================[.rst:
5FindOpenGL
6----------
7
8FindModule for OpenGL and OpenGL Utility Library (GLU).
9
10.. versionchanged:: 3.2
11  X11 is no longer added as a dependency on Unix/Linux systems.
12
13.. versionadded:: 3.10
14  GLVND support on Linux.  See the :ref:`Linux Specific` section below.
15
16Optional COMPONENTS
17^^^^^^^^^^^^^^^^^^^
18
19.. versionadded:: 3.10
20
21This module respects several optional COMPONENTS: ``EGL``, ``GLX``, and
22``OpenGL``.  There are corresponding import targets for each of these flags.
23
24IMPORTED Targets
25^^^^^^^^^^^^^^^^
26
27.. versionadded:: 3.8
28
29This module defines the :prop_tgt:`IMPORTED` targets:
30
31``OpenGL::GL``
32  Defined to the platform-specific OpenGL libraries if the system has OpenGL.
33``OpenGL::GLU``
34  Defined if the system has OpenGL Utility Library (GLU).
35
36.. versionadded:: 3.10
37  Additionally, the following GLVND-specific library targets are defined:
38
39``OpenGL::OpenGL``
40  Defined to libOpenGL if the system is GLVND-based.
41``OpenGL::GLX``
42  Defined if the system has OpenGL Extension to the X Window System (GLX).
43``OpenGL::EGL``
44  Defined if the system has EGL.
45
46Result Variables
47^^^^^^^^^^^^^^^^
48
49This module sets the following variables:
50
51``OPENGL_FOUND``
52 True, if the system has OpenGL and all components are found.
53``OPENGL_XMESA_FOUND``
54 True, if the system has XMESA.
55``OPENGL_GLU_FOUND``
56 True, if the system has GLU.
57``OpenGL_OpenGL_FOUND``
58 True, if the system has an OpenGL library.
59``OpenGL_GLX_FOUND``
60 True, if the system has GLX.
61``OpenGL_EGL_FOUND``
62 True, if the system has EGL.
63``OPENGL_INCLUDE_DIR``
64 Path to the OpenGL include directory.
65``OPENGL_EGL_INCLUDE_DIRS``
66 Path to the EGL include directory.
67``OPENGL_LIBRARIES``
68 Paths to the OpenGL library, windowing system libraries, and GLU libraries.
69 On Linux, this assumes GLX and is never correct for EGL-based targets.
70 Clients are encouraged to use the ``OpenGL::*`` import targets instead.
71
72.. versionadded:: 3.10
73  Variables for GLVND-specific libraries ``OpenGL``, ``EGL`` and ``GLX``.
74
75Cache variables
76^^^^^^^^^^^^^^^
77
78The following cache variables may also be set:
79
80``OPENGL_egl_LIBRARY``
81 Path to the EGL library.
82``OPENGL_glu_LIBRARY``
83 Path to the GLU library.
84``OPENGL_glx_LIBRARY``
85 Path to the GLVND 'GLX' library.
86``OPENGL_opengl_LIBRARY``
87 Path to the GLVND 'OpenGL' library
88``OPENGL_gl_LIBRARY``
89 Path to the OpenGL library.  New code should prefer the ``OpenGL::*`` import
90 targets.
91
92.. versionadded:: 3.10
93  Variables for GLVND-specific libraries ``OpenGL``, ``EGL`` and ``GLX``.
94
95.. _`Linux Specific`:
96
97Linux-specific
98^^^^^^^^^^^^^^
99
100Some Linux systems utilize GLVND as a new ABI for OpenGL.  GLVND separates
101context libraries from OpenGL itself; OpenGL lives in "libOpenGL", and
102contexts are defined in "libGLX" or "libEGL".  GLVND is currently the only way
103to get OpenGL 3+ functionality via EGL in a manner portable across vendors.
104Projects may use GLVND explicitly with target ``OpenGL::OpenGL`` and either
105``OpenGL::GLX`` or ``OpenGL::EGL``.
106
107Projects may use the ``OpenGL::GL`` target (or ``OPENGL_LIBRARIES`` variable)
108to use legacy GL interfaces.  These will use the legacy GL library located
109by ``OPENGL_gl_LIBRARY``, if available.  If ``OPENGL_gl_LIBRARY`` is empty or
110not found and GLVND is available, the ``OpenGL::GL`` target will use GLVND
111``OpenGL::OpenGL`` and ``OpenGL::GLX`` (and the ``OPENGL_LIBRARIES``
112variable will use the corresponding libraries).  Thus, for non-EGL-based
113Linux targets, the ``OpenGL::GL`` target is most portable.
114
115A ``OpenGL_GL_PREFERENCE`` variable may be set to specify the preferred way
116to provide legacy GL interfaces in case multiple choices are available.
117The value may be one of:
118
119``GLVND``
120 If the GLVND OpenGL and GLX libraries are available, prefer them.
121 This forces ``OPENGL_gl_LIBRARY`` to be empty.
122
123 .. versionchanged:: 3.11
124  This is the default, unless policy :policy:`CMP0072` is set to ``OLD``
125  and no components are requeted (since components
126  correspond to GLVND libraries).
127
128``LEGACY``
129 Prefer to use the legacy libGL library, if available.
130
131For EGL targets the client must rely on GLVND support on the user's system.
132Linking should use the ``OpenGL::OpenGL OpenGL::EGL`` targets.  Using GLES*
133libraries is theoretically possible in place of ``OpenGL::OpenGL``, but this
134module does not currently support that; contributions welcome.
135
136``OPENGL_egl_LIBRARY`` and ``OPENGL_EGL_INCLUDE_DIRS`` are defined in the case of
137GLVND.  For non-GLVND Linux and other systems these are left undefined.
138
139macOS-Specific
140^^^^^^^^^^^^^^
141
142On OSX FindOpenGL defaults to using the framework version of OpenGL. People
143will have to change the cache values of OPENGL_glu_LIBRARY and
144OPENGL_gl_LIBRARY to use OpenGL with X11 on OSX.
145#]=======================================================================]
146
147set(_OpenGL_REQUIRED_VARS OPENGL_gl_LIBRARY)
148
149# Provide OPENGL_USE_<C> variables for each component.
150foreach(component ${OpenGL_FIND_COMPONENTS})
151  string(TOUPPER ${component} _COMPONENT)
152  set(OPENGL_USE_${_COMPONENT} 1)
153endforeach()
154
155set(_OpenGL_CACHE_VARS)
156
157if (WIN32)
158
159  if(BORLAND)
160    set (OPENGL_gl_LIBRARY import32 CACHE STRING "OpenGL library for win32")
161    set (OPENGL_glu_LIBRARY import32 CACHE STRING "GLU library for win32")
162  else()
163    set (OPENGL_gl_LIBRARY opengl32 CACHE STRING "OpenGL library for win32")
164    set (OPENGL_glu_LIBRARY glu32 CACHE STRING "GLU library for win32")
165  endif()
166
167  list(APPEND _OpenGL_CACHE_VARS
168    OPENGL_gl_LIBRARY
169    OPENGL_glu_LIBRARY
170    )
171elseif (APPLE)
172  # The OpenGL.framework provides both gl and glu
173  find_library(OPENGL_gl_LIBRARY OpenGL DOC "OpenGL library for OS X")
174  find_library(OPENGL_glu_LIBRARY OpenGL DOC
175    "GLU library for OS X (usually same as OpenGL library)")
176  find_path(OPENGL_INCLUDE_DIR OpenGL/gl.h DOC "Include for OpenGL on OS X")
177  list(APPEND _OpenGL_REQUIRED_VARS OPENGL_INCLUDE_DIR)
178
179  list(APPEND _OpenGL_CACHE_VARS
180    OPENGL_INCLUDE_DIR
181    OPENGL_gl_LIBRARY
182    OPENGL_glu_LIBRARY
183    )
184else()
185  if (CMAKE_SYSTEM_NAME MATCHES "HP-UX")
186    # Handle HP-UX cases where we only want to find OpenGL in either hpux64
187    # or hpux32 depending on if we're doing a 64 bit build.
188    if(CMAKE_SIZEOF_VOID_P EQUAL 4)
189      set(_OPENGL_LIB_PATH
190        /opt/graphics/OpenGL/lib/hpux32/)
191    else()
192      set(_OPENGL_LIB_PATH
193        /opt/graphics/OpenGL/lib/hpux64/
194        /opt/graphics/OpenGL/lib/pa20_64)
195    endif()
196  elseif(CMAKE_SYSTEM_NAME STREQUAL Haiku)
197    set(_OPENGL_LIB_PATH
198      /boot/develop/lib/x86)
199    set(_OPENGL_INCLUDE_PATH
200      /boot/develop/headers/os/opengl)
201  endif()
202
203  # The first line below is to make sure that the proper headers
204  # are used on a Linux machine with the NVidia drivers installed.
205  # They replace Mesa with NVidia's own library but normally do not
206  # install headers and that causes the linking to
207  # fail since the compiler finds the Mesa headers but NVidia's library.
208  # Make sure the NVIDIA directory comes BEFORE the others.
209  #  - Atanas Georgiev <[email protected]>
210  find_path(OPENGL_INCLUDE_DIR GL/gl.h
211    /usr/share/doc/NVIDIA_GLX-1.0/include
212    /usr/openwin/share/include
213    /opt/graphics/OpenGL/include
214    ${_OPENGL_INCLUDE_PATH}
215  )
216  find_path(OPENGL_GLX_INCLUDE_DIR GL/glx.h ${_OPENGL_INCLUDE_PATH})
217  find_path(OPENGL_EGL_INCLUDE_DIR EGL/egl.h ${_OPENGL_INCLUDE_PATH})
218  find_path(OPENGL_xmesa_INCLUDE_DIR GL/xmesa.h
219    /usr/share/doc/NVIDIA_GLX-1.0/include
220    /usr/openwin/share/include
221    /opt/graphics/OpenGL/include
222  )
223  list(APPEND _OpenGL_CACHE_VARS
224    OPENGL_INCLUDE_DIR
225    OPENGL_GLX_INCLUDE_DIR
226    OPENGL_EGL_INCLUDE_DIR
227    OPENGL_xmesa_INCLUDE_DIR
228    )
229
230  # Search for the GLVND libraries.  We do this regardless of COMPONENTS; we'll
231  # take into account the COMPONENTS logic later.
232  find_library(OPENGL_opengl_LIBRARY
233    NAMES OpenGL
234    PATHS ${_OPENGL_LIB_PATH}
235  )
236
237  find_library(OPENGL_glx_LIBRARY
238    NAMES GLX
239    PATHS ${_OPENGL_LIB_PATH}
240    PATH_SUFFIXES libglvnd
241  )
242
243  find_library(OPENGL_egl_LIBRARY
244    NAMES EGL
245    PATHS ${_OPENGL_LIB_PATH}
246    PATH_SUFFIXES libglvnd
247  )
248
249  find_library(OPENGL_glu_LIBRARY
250    NAMES GLU MesaGLU
251    PATHS ${OPENGL_gl_LIBRARY}
252          /opt/graphics/OpenGL/lib
253          /usr/openwin/lib
254          /usr/shlib
255  )
256
257  list(APPEND _OpenGL_CACHE_VARS
258    OPENGL_opengl_LIBRARY
259    OPENGL_glx_LIBRARY
260    OPENGL_egl_LIBRARY
261    OPENGL_glu_LIBRARY
262    )
263
264  set(_OpenGL_GL_POLICY_WARN 0)
265  if(NOT DEFINED OpenGL_GL_PREFERENCE)
266    set(OpenGL_GL_PREFERENCE "")
267  endif()
268  if(NOT OpenGL_GL_PREFERENCE STREQUAL "")
269    # A preference has been explicitly specified.
270    if(NOT OpenGL_GL_PREFERENCE MATCHES "^(GLVND|LEGACY)$")
271      message(FATAL_ERROR
272        "OpenGL_GL_PREFERENCE value '${OpenGL_GL_PREFERENCE}' not recognized.  "
273        "Allowed values are 'GLVND' and 'LEGACY'."
274        )
275    endif()
276  elseif(OpenGL_FIND_COMPONENTS)
277    # No preference was explicitly specified, but the caller did request
278    # at least one GLVND component.  Prefer GLVND for legacy GL.
279    set(OpenGL_GL_PREFERENCE "GLVND")
280  else()
281    # No preference was explicitly specified and no GLVND components were
282    # requested.  Use a policy to choose the default.
283    cmake_policy(GET CMP0072 _OpenGL_GL_POLICY)
284    if("x${_OpenGL_GL_POLICY}x" STREQUAL "xNEWx")
285      set(OpenGL_GL_PREFERENCE "GLVND")
286    else()
287      set(OpenGL_GL_PREFERENCE "LEGACY")
288      if("x${_OpenGL_GL_POLICY}x" STREQUAL "xx")
289        set(_OpenGL_GL_POLICY_WARN 1)
290      endif()
291    endif()
292    unset(_OpenGL_GL_POLICY)
293  endif()
294
295  if("x${OpenGL_GL_PREFERENCE}x" STREQUAL "xGLVNDx" AND OPENGL_opengl_LIBRARY AND OPENGL_glx_LIBRARY)
296    # We can provide legacy GL using GLVND libraries.
297    # Do not use any legacy GL library.
298    set(OPENGL_gl_LIBRARY "")
299  else()
300    # We cannot provide legacy GL using GLVND libraries.
301    # Search for the legacy GL library.
302    find_library(OPENGL_gl_LIBRARY
303      NAMES GL MesaGL
304      PATHS /opt/graphics/OpenGL/lib
305            /usr/openwin/lib
306            /usr/shlib
307            ${_OPENGL_LIB_PATH}
308      PATH_SUFFIXES libglvnd
309      )
310    list(APPEND _OpenGL_CACHE_VARS OPENGL_gl_LIBRARY)
311  endif()
312
313  if(_OpenGL_GL_POLICY_WARN AND OPENGL_gl_LIBRARY AND OPENGL_opengl_LIBRARY AND OPENGL_glx_LIBRARY)
314    cmake_policy(GET_WARNING CMP0072 _cmp0072_warning)
315    message(AUTHOR_WARNING
316      "${_cmp0072_warning}\n"
317      "FindOpenGL found both a legacy GL library:\n"
318      "  OPENGL_gl_LIBRARY: ${OPENGL_gl_LIBRARY}\n"
319      "and GLVND libraries for OpenGL and GLX:\n"
320      "  OPENGL_opengl_LIBRARY: ${OPENGL_opengl_LIBRARY}\n"
321      "  OPENGL_glx_LIBRARY: ${OPENGL_glx_LIBRARY}\n"
322      "OpenGL_GL_PREFERENCE has not been set to \"GLVND\" or \"LEGACY\", so for "
323      "compatibility with CMake 3.10 and below the legacy GL library will be used."
324      )
325  endif()
326  unset(_OpenGL_GL_POLICY_WARN)
327
328  # FPHSA cannot handle "this OR that is required", so we conditionally set what
329  # it must look for.  First clear any previous config we might have done:
330  set(_OpenGL_REQUIRED_VARS)
331
332  # now we append the libraries as appropriate.  The complicated logic
333  # basically comes down to "use libOpenGL when we can, and add in specific
334  # context mechanisms when requested, or we need them to preserve the previous
335  # default where glx is always available."
336  if((NOT OPENGL_USE_EGL AND
337      NOT OPENGL_opengl_LIBRARY AND
338          OPENGL_glx_LIBRARY AND
339      NOT OPENGL_gl_LIBRARY) OR
340     (NOT OPENGL_USE_EGL AND
341      NOT OPENGL_glx_LIBRARY AND
342      NOT OPENGL_gl_LIBRARY) OR
343     (NOT OPENGL_USE_EGL AND
344          OPENGL_opengl_LIBRARY AND
345          OPENGL_glx_LIBRARY) OR
346     (    OPENGL_USE_EGL))
347    list(APPEND _OpenGL_REQUIRED_VARS OPENGL_opengl_LIBRARY)
348  endif()
349
350  # GLVND GLX library.  Preferred when available.
351  if((NOT OPENGL_USE_OPENGL AND
352      NOT OPENGL_USE_GLX AND
353      NOT OPENGL_USE_EGL AND
354      NOT OPENGL_glx_LIBRARY AND
355      NOT OPENGL_gl_LIBRARY) OR
356     (    OPENGL_USE_GLX AND
357      NOT OPENGL_USE_EGL AND
358      NOT OPENGL_glx_LIBRARY AND
359      NOT OPENGL_gl_LIBRARY) OR
360     (NOT OPENGL_USE_EGL AND
361          OPENGL_opengl_LIBRARY AND
362          OPENGL_glx_LIBRARY) OR
363     (OPENGL_USE_GLX AND OPENGL_USE_EGL))
364    list(APPEND _OpenGL_REQUIRED_VARS OPENGL_glx_LIBRARY)
365  endif()
366
367  # GLVND EGL library.
368  if(OPENGL_USE_EGL)
369    list(APPEND _OpenGL_REQUIRED_VARS OPENGL_egl_LIBRARY)
370  endif()
371
372  # Old-style "libGL" library: used as a fallback when GLVND isn't available.
373  if((NOT OPENGL_USE_EGL AND
374      NOT OPENGL_opengl_LIBRARY AND
375          OPENGL_glx_LIBRARY AND
376          OPENGL_gl_LIBRARY) OR
377     (NOT OPENGL_USE_EGL AND
378      NOT OPENGL_glx_LIBRARY AND
379          OPENGL_gl_LIBRARY))
380    list(APPEND _OpenGL_REQUIRED_VARS OPENGL_gl_LIBRARY)
381  endif()
382
383  # We always need the 'gl.h' include dir.
384  list(APPEND _OpenGL_REQUIRED_VARS OPENGL_INCLUDE_DIR)
385
386  unset(_OPENGL_INCLUDE_PATH)
387  unset(_OPENGL_LIB_PATH)
388
389  find_library(OPENGL_glu_LIBRARY
390    NAMES GLU MesaGLU
391    PATHS ${OPENGL_gl_LIBRARY}
392          /opt/graphics/OpenGL/lib
393          /usr/openwin/lib
394          /usr/shlib
395  )
396endif ()
397
398if(OPENGL_xmesa_INCLUDE_DIR)
399  set( OPENGL_XMESA_FOUND "YES" )
400else()
401  set( OPENGL_XMESA_FOUND "NO" )
402endif()
403
404if(OPENGL_glu_LIBRARY)
405  set( OPENGL_GLU_FOUND "YES" )
406else()
407  set( OPENGL_GLU_FOUND "NO" )
408endif()
409
410# OpenGL_OpenGL_FOUND is a bit unique in that it is okay if /either/ libOpenGL
411# or libGL is found.
412# Using libGL with libEGL is never okay, though; we handle that case later.
413if(NOT OPENGL_opengl_LIBRARY AND NOT OPENGL_gl_LIBRARY)
414  set(OpenGL_OpenGL_FOUND FALSE)
415else()
416  set(OpenGL_OpenGL_FOUND TRUE)
417endif()
418
419if(OPENGL_glx_LIBRARY AND OPENGL_GLX_INCLUDE_DIR)
420  set(OpenGL_GLX_FOUND TRUE)
421else()
422  set(OpenGL_GLX_FOUND FALSE)
423endif()
424
425if(OPENGL_egl_LIBRARY AND OPENGL_EGL_INCLUDE_DIR)
426  set(OpenGL_EGL_FOUND TRUE)
427else()
428  set(OpenGL_EGL_FOUND FALSE)
429endif()
430
431# User-visible names should be plural.
432if(OPENGL_EGL_INCLUDE_DIR)
433  set(OPENGL_EGL_INCLUDE_DIRS ${OPENGL_EGL_INCLUDE_DIR})
434endif()
435
436include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
437if (CMAKE_FIND_PACKAGE_NAME STREQUAL "GLU")
438  # FindGLU include()'s this module. It's an old pattern, but rather than
439  # trying to suppress this from outside the module (which is then sensitive to
440  # the contents, detect the case in this module and suppress it explicitly.
441  set(FPHSA_NAME_MISMATCHED 1)
442endif ()
443FIND_PACKAGE_HANDLE_STANDARD_ARGS(OpenGL REQUIRED_VARS ${_OpenGL_REQUIRED_VARS}
444                                  HANDLE_COMPONENTS)
445unset(FPHSA_NAME_MISMATCHED)
446unset(_OpenGL_REQUIRED_VARS)
447
448# OpenGL:: targets
449if(OPENGL_FOUND)
450  # ::OpenGL is a GLVND library, and thus Linux-only: we don't bother checking
451  # for a framework version of this library.
452  if(OPENGL_opengl_LIBRARY AND NOT TARGET OpenGL::OpenGL)
453    if(IS_ABSOLUTE "${OPENGL_opengl_LIBRARY}")
454      add_library(OpenGL::OpenGL UNKNOWN IMPORTED)
455      set_target_properties(OpenGL::OpenGL PROPERTIES IMPORTED_LOCATION
456                            "${OPENGL_opengl_LIBRARY}")
457    else()
458      add_library(OpenGL::OpenGL INTERFACE IMPORTED)
459      set_target_properties(OpenGL::OpenGL PROPERTIES IMPORTED_LIBNAME
460                            "${OPENGL_opengl_LIBRARY}")
461    endif()
462    set_target_properties(OpenGL::OpenGL PROPERTIES INTERFACE_INCLUDE_DIRECTORIES
463                          "${OPENGL_INCLUDE_DIR}")
464  endif()
465
466  # ::GLX is a GLVND library, and thus Linux-only: we don't bother checking
467  # for a framework version of this library.
468  if(OpenGL_GLX_FOUND AND NOT TARGET OpenGL::GLX AND TARGET OpenGL::OpenGL)
469    if(IS_ABSOLUTE "${OPENGL_glx_LIBRARY}")
470      add_library(OpenGL::GLX UNKNOWN IMPORTED)
471      set_target_properties(OpenGL::GLX PROPERTIES IMPORTED_LOCATION
472                            "${OPENGL_glx_LIBRARY}")
473    else()
474      add_library(OpenGL::GLX INTERFACE IMPORTED)
475      set_target_properties(OpenGL::GLX PROPERTIES IMPORTED_LIBNAME
476                            "${OPENGL_glx_LIBRARY}")
477    endif()
478    set_target_properties(OpenGL::GLX PROPERTIES INTERFACE_LINK_LIBRARIES
479                          OpenGL::OpenGL)
480    set_target_properties(OpenGL::GLX PROPERTIES INTERFACE_INCLUDE_DIRECTORIES
481                          "${OPENGL_GLX_INCLUDE_DIR}")
482  endif()
483
484  if(OPENGL_gl_LIBRARY AND NOT TARGET OpenGL::GL)
485    # A legacy GL library is available, so use it for the legacy GL target.
486    if(IS_ABSOLUTE "${OPENGL_gl_LIBRARY}")
487      add_library(OpenGL::GL UNKNOWN IMPORTED)
488      if(OPENGL_gl_LIBRARY MATCHES "/([^/]+)\\.framework$")
489        set(_gl_fw "${OPENGL_gl_LIBRARY}/${CMAKE_MATCH_1}")
490        if(EXISTS "${_gl_fw}.tbd")
491          string(APPEND _gl_fw ".tbd")
492        endif()
493        set_target_properties(OpenGL::GL PROPERTIES
494          IMPORTED_LOCATION "${_gl_fw}")
495      else()
496        set_target_properties(OpenGL::GL PROPERTIES
497          IMPORTED_LOCATION "${OPENGL_gl_LIBRARY}")
498      endif()
499    else()
500      add_library(OpenGL::GL INTERFACE IMPORTED)
501      set_target_properties(OpenGL::GL PROPERTIES
502        IMPORTED_LIBNAME "${OPENGL_gl_LIBRARY}")
503    endif()
504    set_target_properties(OpenGL::GL PROPERTIES
505      INTERFACE_INCLUDE_DIRECTORIES "${OPENGL_INCLUDE_DIR}")
506  elseif(NOT TARGET OpenGL::GL AND TARGET OpenGL::OpenGL AND TARGET OpenGL::GLX)
507    # A legacy GL library is not available, but we can provide the legacy GL
508    # target using GLVND OpenGL+GLX.
509    add_library(OpenGL::GL INTERFACE IMPORTED)
510    set_target_properties(OpenGL::GL PROPERTIES INTERFACE_LINK_LIBRARIES
511                          OpenGL::OpenGL)
512    set_property(TARGET OpenGL::GL APPEND PROPERTY INTERFACE_LINK_LIBRARIES
513                 OpenGL::GLX)
514    set_target_properties(OpenGL::GL PROPERTIES INTERFACE_INCLUDE_DIRECTORIES
515                          "${OPENGL_INCLUDE_DIR}")
516  endif()
517
518  # ::EGL is a GLVND library, and thus Linux-only: we don't bother checking
519  # for a framework version of this library.
520  # Note we test for OpenGL::OpenGL as a target.  When this module is updated to
521  # support GLES, we would additionally want to check for the hypothetical GLES
522  # target and enable EGL if either ::GLES or ::OpenGL is created.
523  if(TARGET OpenGL::OpenGL AND OpenGL_EGL_FOUND AND NOT TARGET OpenGL::EGL)
524    if(IS_ABSOLUTE "${OPENGL_egl_LIBRARY}")
525      add_library(OpenGL::EGL UNKNOWN IMPORTED)
526      set_target_properties(OpenGL::EGL PROPERTIES IMPORTED_LOCATION
527                            "${OPENGL_egl_LIBRARY}")
528    else()
529      add_library(OpenGL::EGL INTERFACE IMPORTED)
530      set_target_properties(OpenGL::EGL PROPERTIES IMPORTED_LIBNAME
531                            "${OPENGL_egl_LIBRARY}")
532    endif()
533    set_target_properties(OpenGL::EGL PROPERTIES INTERFACE_LINK_LIBRARIES
534                          OpenGL::OpenGL)
535    # Note that EGL's include directory is different from OpenGL/GLX's!
536    set_target_properties(OpenGL::EGL PROPERTIES INTERFACE_INCLUDE_DIRECTORIES
537                          "${OPENGL_EGL_INCLUDE_DIR}")
538  endif()
539
540  if(OPENGL_GLU_FOUND AND NOT TARGET OpenGL::GLU)
541    if(IS_ABSOLUTE "${OPENGL_glu_LIBRARY}")
542      add_library(OpenGL::GLU UNKNOWN IMPORTED)
543      if(OPENGL_glu_LIBRARY MATCHES "/([^/]+)\\.framework$")
544        set(_glu_fw "${OPENGL_glu_LIBRARY}/${CMAKE_MATCH_1}")
545        if(EXISTS "${_glu_fw}.tbd")
546          string(APPEND _glu_fw ".tbd")
547        endif()
548        set_target_properties(OpenGL::GLU PROPERTIES
549          IMPORTED_LOCATION "${_glu_fw}")
550      else()
551        set_target_properties(OpenGL::GLU PROPERTIES
552          IMPORTED_LOCATION "${OPENGL_glu_LIBRARY}")
553      endif()
554    else()
555      add_library(OpenGL::GLU INTERFACE IMPORTED)
556      set_target_properties(OpenGL::GLU PROPERTIES
557        IMPORTED_LIBNAME "${OPENGL_glu_LIBRARY}")
558    endif()
559    set_target_properties(OpenGL::GLU PROPERTIES
560      INTERFACE_LINK_LIBRARIES OpenGL::GL)
561  endif()
562
563  # OPENGL_LIBRARIES mirrors OpenGL::GL's logic ...
564  if(OPENGL_gl_LIBRARY)
565    set(OPENGL_LIBRARIES ${OPENGL_gl_LIBRARY})
566  elseif(TARGET OpenGL::OpenGL AND TARGET OpenGL::GLX)
567    set(OPENGL_LIBRARIES ${OPENGL_opengl_LIBRARY} ${OPENGL_glx_LIBRARY})
568  else()
569    set(OPENGL_LIBRARIES "")
570  endif()
571  # ... and also includes GLU, if available.
572  if(TARGET OpenGL::GLU)
573    list(APPEND OPENGL_LIBRARIES ${OPENGL_glu_LIBRARY})
574  endif()
575endif()
576
577# This deprecated setting is for backward compatibility with CMake1.4
578set(OPENGL_LIBRARY ${OPENGL_LIBRARIES})
579# This deprecated setting is for backward compatibility with CMake1.4
580set(OPENGL_INCLUDE_PATH ${OPENGL_INCLUDE_DIR})
581
582mark_as_advanced(${_OpenGL_CACHE_VARS})
583unset(_OpenGL_CACHE_VARS)
584