diff options
| -rw-r--r-- | Modules/FindOpenGL.cmake | 69 |
1 files changed, 56 insertions, 13 deletions
diff --git a/Modules/FindOpenGL.cmake b/Modules/FindOpenGL.cmake index 1c74012..9063492 100644 --- a/Modules/FindOpenGL.cmake +++ b/Modules/FindOpenGL.cmake @@ -84,12 +84,26 @@ # ``OpenGL::GLX`` or ``OpenGL::EGL``. # # Projects may use the ``OpenGL::GL`` target (or ``OPENGL_LIBRARIES`` variable) -# to use legacy GL. By default, these will use the legacy libGL library file. -# 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. +# 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* @@ -206,13 +220,42 @@ else() /usr/shlib /usr/X11R6/lib ) - find_library(OPENGL_gl_LIBRARY - NAMES GL MesaGL - PATHS /opt/graphics/OpenGL/lib - /usr/openwin/lib - /usr/shlib /usr/X11R6/lib - ${_OPENGL_LIB_PATH} - ) + if(NOT DEFINED OpenGL_GL_PREFERENCE) + set(OpenGL_GL_PREFERENCE "") + endif() + if(NOT OpenGL_GL_PREFERENCE STREQUAL "") + # A preference has been explicitly specified. + if(NOT OpenGL_GL_PREFERENCE MATCHES "^(GLVND|LEGACY)$") + message(FATAL_ERROR + "OpenGL_GL_PREFERENCE value '${OpenGL_GL_PREFERENCE}' not recognized. " + "Allowed values are 'GLVND' and 'LEGACY'." + ) + endif() + elseif(OpenGL_FIND_COMPONENTS) + # No preference was explicitly specified, but the caller did request + # at least one GLVND component. Prefer GLVND for legacy GL. + set(OpenGL_GL_PREFERENCE "GLVND") + else() + # No preference was explicitly specified and no GLVND components were + # requested. Prefer libGL for legacy GL. + set(OpenGL_GL_PREFERENCE "LEGACY") + endif() + + if("x${OpenGL_GL_PREFERENCE}x" STREQUAL "xGLVNDx" AND OPENGL_opengl_LIBRARY AND OPENGL_glx_LIBRARY) + # We can provide legacy GL using GLVND libraries. + # Do not use any legacy GL library. + set(OPENGL_gl_LIBRARY "") + else() + # We cannot provide legacy GL using GLVND libraries. + # Search for the legacy GL library. + find_library(OPENGL_gl_LIBRARY + NAMES GL MesaGL + PATHS /opt/graphics/OpenGL/lib + /usr/openwin/lib + /usr/shlib /usr/X11R6/lib + ${_OPENGL_LIB_PATH} + ) + endif() # FPHSA cannot handle "this OR that is required", so we conditionally set what # it must look for. First clear any previous config we might have done: |