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-rw-r--r--CMake/resources.cmake3
-rw-r--r--examples/CMakeLists.txt82
-rw-r--r--examples/OpenGL3-glut-test.cxx5
-rw-r--r--examples/OpenGL3test.cxx4
4 files changed, 68 insertions, 26 deletions
diff --git a/CMake/resources.cmake b/CMake/resources.cmake
index 3fd8205f1..eaea18c07 100644
--- a/CMake/resources.cmake
+++ b/CMake/resources.cmake
@@ -152,14 +152,13 @@ endif((NOT APPLE) OR FLTK_BACKEND_X11)
find_library(LIB_freetype freetype)
find_library(LIB_GL GL)
find_library(LIB_MesaGL MesaGL)
-find_library(LIB_GLEW NAMES GLEW glew32)
find_library(LIB_jpeg jpeg)
find_library(LIB_png png)
find_library(LIB_zlib z)
find_library(LIB_m m)
mark_as_advanced(LIB_dl LIB_fontconfig LIB_freetype)
-mark_as_advanced(LIB_GL LIB_MesaGL LIB_GLEW)
+mark_as_advanced(LIB_GL LIB_MesaGL)
mark_as_advanced(LIB_jpeg LIB_png LIB_zlib)
mark_as_advanced(LIB_m)
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index 3e44d29fa..a8dfa970f 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -80,7 +80,7 @@ set(FLUID_SOURCES
)
############################################################
-# examples requiring fltk_images
+# examples requiring fltk::images
############################################################
set(IMAGE_SOURCES
@@ -100,7 +100,7 @@ set(CAIRO_SOURCES
)
############################################################
-# examples requiring OpenGL + libGLEW
+# examples requiring OpenGL3 + GLEW
############################################################
set(OPENGL_SOURCES
@@ -141,33 +141,79 @@ foreach(src ${CAIRO_SOURCES})
endforeach(src)
############################################################
-# create example programs with OpenGL + libGLEW
+# create example programs with OpenGL3 + GLEW
############################################################
+#
+# Note 1: macOS (Quartz) does not need GLEW, it's included in OpenGL
+# Note 2: find_package(GLEW) finds either shared or static libs or both.
+# Note 3: on Windows we set the variable GLEW_USE_STATIC_LIBS=TRUE because
+# we *want* to find static libs but we *can* also use shared libs.
+# Note 4: FindGLEW.cmake changed the library suffixes for MinGW in CMake 3.28.0,
+# obviously "assuming" that ".lib" is Visual Studio only. There have been
+# discussions about finding the "wrong" libraries since CMake 3.25 or so.
+# Therefore the static lib "glew32s.lib" is not found if CMake 3.28 or
+# higher is used (current version, as of this writing: 3.29.3). However,
+# this assumption is probably not true for a pure C library (glew32s).
+# This library *is* found and works well with CMake 3.15.0 - 3.27.9.
+# Users may need to copy or rename "glew32s.lib" to "glew32s.a"
+# if CMake 3.28 or higher is used.
+# Albrecht-S, May 13, 2024
+
+if(OPENGL_FOUND)
+ if(WIN32)
+ set(GLEW_USE_STATIC_LIBS TRUE)
+ endif()
+ set(_glew_lib GLEW::glew)
+ set(_glew_static FALSE)
+ if(APPLE AND NOT FLTK_BACKEND_X11) # macOS Quartz
+ set(_glew_lib)
+ set(GLEW_FOUND TRUE)
+ else()
+ # set(GLEW_VERBOSE TRUE) # make `find_package(GLEW)` verbose
+ set(_CMAKE_PREFIX_PATH_SAVED ${CMAKE_PREFIX_PATH})
+ set(CMAKE_PREFIX_PATH ${FLTK_GLEW_DIR} ${CMAKE_PREFIX_PATH})
+ find_package(GLEW MODULE)
+ set(CMAKE_PREFIX_PATH ${_CMAKE_PREFIX_PATH_SAVED})
+ unset(_CMAKE_PREFIX_PATH_SAVED)
+ # Did we find the static lib? If yes, use it
+ if(TARGET GLEW::glew_s)
+ set(_glew_lib GLEW::glew_s)
+ set(_glew_static TRUE)
+ endif()
+ endif()
-# Note: macOS does not need libGLEW
+ if(0) # Debug
+ fl_debug_var(OPENGL_FOUND)
+ fl_debug_var(GLEW_FOUND)
+ fl_debug_var(GLEW_DIR)
+ fl_debug_var(_glew_lib)
+ fl_debug_target(GLEW::glew)
+ fl_debug_target(GLEW::glew_s)
+ fl_debug_target(GLEW::GLEW)
+ endif() # /Debug
-if(APPLE AND NOT FLTK_BACKEND_X11)
- if(NOT LIB_GLEW)
- set(LIB_GLEW TRUE)
- endif()
- set(REQUIRED_LIBS fltk::gl)
-else()
- set(REQUIRED_LIBS fltk::gl ${LIB_GLEW})
-endif()
+endif(OPENGL_FOUND)
+
+if(OPENGL_FOUND AND (TARGET "${_glew_lib}" OR APPLE))
+
+ # GLEW was found, create the OpenGL3 targets:
-if(OPENGL_FOUND AND LIB_GLEW)
foreach(tgt ${OPENGL_SOURCES})
- fl_create_example(${tgt} ${tgt}.cxx "${REQUIRED_LIBS}")
+ fl_create_example(${tgt} ${tgt}.cxx "fltk::gl;${_glew_lib}")
set_property(TARGET ${tgt} PROPERTY CXX_STANDARD 11)
set_property(TARGET ${tgt} PROPERTY CXX_STANDARD_REQUIRED TRUE)
+ # define preprocessor macro GLEW_STATIC only if we link to the static lib
+ if(_glew_static)
+ target_compile_definitions(${tgt} PRIVATE "GLEW_STATIC")
+ endif()
endforeach(tgt)
else()
+
message(STATUS
- "OpenGL or libGLEW not present: OpenGL example programs will not be built.")
+ "OpenGL or GLEW not present: OpenGL3 example programs will not be built.")
fl_debug_var(OPENGL_FOUND)
- fl_debug_var(LIB_GLEW)
+ fl_debug_var(GLEW_FOUND)
message("")
-endif(OPENGL_FOUND AND LIB_GLEW)
-unset(REQUIRED_LIBS)
+endif() # (OPENGL_FOUND AND TARGET "${_glew_lib}")
diff --git a/examples/OpenGL3-glut-test.cxx b/examples/OpenGL3-glut-test.cxx
index 311a02603..8693b3861 100644
--- a/examples/OpenGL3-glut-test.cxx
+++ b/examples/OpenGL3-glut-test.cxx
@@ -19,11 +19,10 @@
# define GL_DO_NOT_WARN_IF_MULTI_GL_VERSION_HEADERS_INCLUDED 1
# include <OpenGL/gl3.h> // defines OpenGL 3.0+ functions
#else
-# if defined(_WIN32)
-# define GLEW_STATIC 1
-# endif
+// Note: GLEW_STATIC is defined by CMake if the static lib is linked
# include <GL/glew.h>
#endif
+
#include <FL/glut.H>
#include <FL/fl_ask.H>
#include <stdio.h>
diff --git a/examples/OpenGL3test.cxx b/examples/OpenGL3test.cxx
index deaf2ec8f..c9f0d59e5 100644
--- a/examples/OpenGL3test.cxx
+++ b/examples/OpenGL3test.cxx
@@ -25,9 +25,7 @@
#if defined(__APPLE__)
# include <OpenGL/gl3.h> // defines OpenGL 3.0+ functions
#else
-# if defined(_WIN32)
-# define GLEW_STATIC 1
-# endif
+// Note: GLEW_STATIC is defined by CMake if the static lib is linked
# include <GL/glew.h>
#endif
#include <FL/gl.h> // for gl_texture_reset()